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Research ArticleHeat Treatment and Ventilation Optimization in a Deep Mine

Xingxin Nie Xiaobin Wei Xiaochen Li and Caiwu Lu

School of Management Xirsquoan University of Architecture and Technology Xirsquoan Shaanxi 710055 China

Correspondence should be addressed to Xingxin Nie 670127529qqcom and Xiaobin Wei 1462658088qqcom

Received 19 March 2018 Accepted 14 June 2018 Published 1 August 2018

Academic Editor Hugo Rodrigues

Copyright copy 2018 Xingxin Nie et al is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

In order to address the issue of high temperatures and thermal damages in deep mines the factors causing downhole heat damageat high temperatures were analyzed the mine ventilation system was optimized and rebuilt and a cooling system was establishede proposed cooling system uses mine water as the cooling source and its features are based on the analysis of traditional coolingsystemse current ventilation system in the 1118m deep pit of the Jinqu GoldMine was evaluated and the ventilation networkventilation equipment and ventilation structures near the underground working face were optimizede low-temperature minewater stored in the middle section of the mine at 640m depth was used as the cooling source and a cooling system was establishednear the 440m deep middle return well to alleviate the high-temperature and high-humidity conditions of the 280m deep middle-western area e results show that the effective air volume in the west wing at 280m was 30m3s the operating ambienttemperature was 276degC the relative humidity was reduced to 76 and the temperature was reduced by 5-6degC after the op-timization of the system

1 Introduction

In an era of rapid development of the global economy theenergy dependence is increasing rapidly [1ndash4] As theshallow mineral resources on Earthrsquos surface have beendepleted [5] countries worldwide have successively begunto mine deep resources As the mining depth increases thetemperature of the rock increases and the heat damagecaused by the ground temperatures and other factors isamplified [6ndash11] For example at a depth of 900m ina mine in Germany the average temperature is 41degC and atthe mining depth of 1712m the maximum temperature is50degC In gold mines in India at a depth of 3000m thegeothermal temperature is more than 60degC e worldrsquosdeepest underground mine is South Africarsquos Carletonvillegold deposit the mining depth is 4000m and the groundtemperatures is 70degC At present China is also encoun-tering the problem of high temperatures in deep mines asin the Shandong Sun Cun mine [12] the Tongling Shi-zishan copper mine [13] and the Fushun Hongtoushancopper mine [14] where the mining depth is more than1000m and the geothermal temperature is 45degC egeneral distribution of high temperatures and heat damage

in deep mines in China is shown in Figure 1 e hot andhumid working environment has seriously endangered theminersrsquo health [15ndash18] according to Chinarsquos TechnicalSpecification for Ventilation System of Metallic and Non-Metallic Underground Mine the air temperature indownhole operation sites shall not exceed 28degC [19]therefore it is very important and of practical signifi-cance to minimize the heat damage in undergroundhigh-temperature and heat damage-prone working envi-ronments e high-temperature high-humidity and low-velocity work environment on the working surface in deepmines will cause the central nervous system to be inhibitedby workers working underground for a long period oftime e symptoms include mental retardation lack ofconcentration and decreased ability to work At the sametime the environment is hot and humid Working fora long time will also make the workers feel un-comfortable irritated and have eczema and other dis-eases that will seriously affect the safety productionefficiency of the mine Solving the problem of ventilationdifficulties and high-temperature heat damage in deepmines can not only protect the physical and mentalhealth of underground miners but also help improve the

HindawiAdvances in Civil EngineeringVolume 2018 Article ID 1529490 12 pageshttpsdoiorg10115520181529490

production eciency of deep mine operating surfacesand contribute to the exploitation of mineral resourcesrich in the depth of the Earth

High-temperature thermal damage in undergroundmines can be minimized by nonarticial refrigerationcooling and articial refrigeration cooling Common non-articial refrigeration cooling methods include ventilationcooling heat insulation and personal protection Commonarticial cooling methods include water cooling ice coolingand thermoelectric cooling combined with cogenerationHowever nonarticial refrigeration cooling methods cannotbe applied in deep mines to minimize high temperatures dueto the limitations in the cooling capacity Yuan et al [20]proposed a new coupled cooling method of Latent Heat ermal Energy Storage (LHTES) combined with Pre-cooling of Envelope (PE) Guo and Chen [21] used thedeep well return air as the cold source of the cooling systemto achieve cooling and dehumidication on the workingsurface Shi et al [22] used liquid nitrogen to inject into theworking face to achieve cooling eect Guo et al [23] usedthe heat of the bathing water on the surface and createda refrigeration unit to achieve a heat exchange between thechilled water and the high-temperature air on the workingsurface the heat created by the condensation of the re-frigeration unit was recovered and the thermal hazard of thehigh temperatures in the mine was converted into heatenergy thereby improving the energy eciency Wang et al[24] optimized a ventilation system and increased theventilation of a mine and the distribution of the air vol-ume to accelerate the downhole airow to achieve cooling

Zou et al [25] used the theories of uid mechanics and heattransfer to develop heat insulation materials in the minemain ventilation tunnel to achieve heat insulation heatremoval and cooling Zhang [26] used combined heat andpower cogeneration technology using steam lithium bro-mide chillers and centrifugal chillers for heating powergeneration and refrigeration to improve the energy utili-zation In this study we propose a downhole centralizedcooling system using mine water as the cooling source witha focus on underground mines with inow water or waterseepage e method is based on the principle of heat ex-change between the cold mine water and the high airtemperatures of the working area and minimizes the heatdamage in the working area e cooling system assisted bymine water source cooling is to reduce the output of re-frigeration unit cooling capacity by using the cold energyhidden by the groundwater source to save the running costof cooling and cooling system In addition the condensingheat discharged by the cooling and cooling system can beabsorbed by the cold energy contained in the mine watersource itself reducing the emission of condensation heat andreducing the secondary thermal hazards generatedunderground

2 Thermal Damage Analysis ofHigh-Temperature Mine

e related research shows that the fundamental cause of thehigh-temperature heat damage near the working face of themine is the concentration of the heat on the working surface

Eastern north heat damageEastern heat damageEastern south heat damage

Figure 1 Distribution map of high-temperature mine in deep mining in China

2 Advances in Civil Engineering

because the heat cannot be discharged from the well in timeis results in an increase in the ambient temperature of theworking surface erefore the main reasons for the high-temperature heat damage in deep wells are the heat releasefrom underground heat sources and the poor air circulation

21 High-Temperature Heat Release

211 Heat Radiating from the Well Rock e original rocktemperature shows a nonlinear increase with the increasein the depth of the stratume thermal physical properties ofthe stratum rock in deep mining have a great influence on thehigh-temperature thermal damage [5] High-temperatureunderground rock releases heat through heat conductionand convection due to heat exchange with the air resulting inincreased enthalpy in the air and in high air temperatures inthe roadways In engineering practice the formula for cal-culating the heat transfer between a high-temperature wallrock and the air in the roadway is

Qr KτUL trm minus t( 1113857 (1)

Kτ 1163

196vB( 1113857 + 00441 (2)

where Qr is the heat transfer of the surrounding rock in thetunnel kW Kτ is the unstable heat transfer coefficientbetween the surrounding rock and the airflow kW(m2middotdegC)U is the perimeter of the mine roadway m L is the length ofwell m trm is the average primary rock temperature degC t isthe average temperature of the air in the mine shaft degC vB isthe average velocity of the airflow in the mine shaft ms

However in the real life the wall surface of undergroundmine tunnel is not dry and there is water seepage in thesurrounding rock wall of the roadway e evaporation ofmoisture will absorb part of the heat to generate heat andmoisture exchange erefore the latent heat exchangebetween the water and wind flow in the tunnel wall iscalculated It is required e formula for calculating latentheat exchange between water and air is

Qw βFkB pw minuspB( 1113857 (3)

β 00846 + 00262vB (4)

kB 101325

B (5)

where Qw is the amount of latent heat exchange betweenwater and winds kW β is latent heat exchange coefficientJmiddotsminus1middotNminus1 F is the heat dissipation surface area of water m2kB is the pressure correction factor pw is the saturated steampressure at the water surface temperature kPa pB is thepartial pressure of water vapor in the air kPa B is thedownhole atmospheric pressure kPa

212 Electromechanical Equipment Is Exothermic With thecontinuous improvement in the mechanization of minemining the exothermic heat of the electromechanical

equipment in the downhole production process has be-come a major heat source for high-temperature thermalhazards downhole [27] Mining equipment wind tur-bines transportation equipment exploration equipmentand lighting are powered by electrical energy and releaseheat e equation for heat generated by electrome-chanical equipment during the operation is

Qd 1113944 φNd (6)

where Qd is the heating capacity of the electromechanicalequipment to the downhole airflow kW φ is the heatdissipation coefficient of the electromechanical equipmentand Nd is the total power of the electromechanical equip-ment operating at the same time kW

e exothermic heat of electromechanical equipment isan important heat source for heat dissipation from thedownhole heat source e heat dissipation coefficient of theelectromechanical equipment is an important factor af-fecting the heat dissipation of the equipment e heatdissipation coefficient of the equipment is determinedaccording to its own characteristics so the heat dissipationcoefficient of different equipment is different In this paperthe heat dissipation coefficient of the downhole electro-mechanical equipment is determined according to thecharacteristics of the equipment itself and the on-siteconditions

213 Heat Released during Ore Transportation e newlymined ore is exposed to the air which increases the contactarea with the downhole air and speeds up the cooling of theore e emitted heat is absorbed by the airflow in thetransportation lanee heat dissipation efficiency of the orebeingmined is faster than that of unmined ore therefore theheat emitted by the ore during transport cannot be ignorede equation of the exothermic reaction of the ore duringtransport is

Qk 00024L08

tr minus twm( 1113857mCm (7)

where Qk is the heat release of ore during transportationkW L is the distance of ore transportation m tr is theaverage temperature of ore in transit degC twm is the averagetemperature of the air in the transportation lane degC m is theore transport capacity kgs and Cm is the specific heatcapacity of the ore kJ(kgmiddotdegC)

214 Heat Release from the Air due to CompressionWhen fresh air flows from the outside to the well bottomsurface the air pressure increases with the increase in thedepth According to the principles of air compression andheat release the air will release a certain amount of heatduring the compression process Under adiabatic condi-tions the airflow will flow about 102m vertically and itstemperature increases about 1degC [28] Under normal cir-cumstances there is a heat and moisture exchange betweenthe wellbore and the airflow in the air intake tunnele heatbalance equation for these conditions is

Advances in Civil Engineering 3

G i2 minus i1( 1113857minusZ1 minusZ2

427GminusG

ω22 minusω2

12 times 427

Qx + Qq + Qj minusQ1

(8)

where Qx is the sensible heat in the heat transfer from theborehole wall to the air Js Qq is the latent heat in the heattransfer from the borehole wall to the air Js Qj is the localheat release Js Q1 is the heat that evaporates from thesurface of a water droplet due to air absorption Js G is theventilation kgs and 1427 is the work heat equivalentJkgfmiddotm

Under normal circumstances when there is little changein the wind speed the wellbore can be defined as ω2 ω1then (8) can be changed to

G i2 minus i1( 1113857 ΔZ427

G + Qx + Qq minusQ1 (9)

In the adiabatic state the following is consideredQx + Qq minusQ1 0

erefore only the adiabatic heat of compression iscalculated here e equation can be simplified as

Qheating ΔZ427

G (10)

where ΔZ is the height difference between the ground andthe mining working face

However for mines that are mined in reality the mineroadway is not adiabatic and the sensible heat and latentheat in the mine will occur during the flow of air ereforein actual mining wells the heat generated by self-compression for every 100m drop in air is insufficientdue to the presence of heat exchange and its own temper-ature is increased by 1degC rough experiments it can beconcluded that the temperature rises for every 100m of airdrop 04-05degC

22 Poor Ventilation of the Working Surface Mine ventila-tion systems are important for the safe operation of un-derground mines and provide fresh airflow and remove thecontaminated air but also lower the heat and humidity of theworking surface Poor ventilation in the work area is one ofthe main causes of high temperatures and heat damage onthe underground working surface When the ventilation ispoor the high temperature can affect the physical andmental health and the work efficiency of mine employees

221 Ventilation Networks Are Complex and Changeablee layout of the ventilation network is a core componentof the mine ventilation system and determines its efficiencye underground environment is complex and variable asunderground mining explorations increase In many casesthe layout of the originally planned ventilation networkundergoes tremendous changes as the mine expands Asa result the underground ventilation network needs to beoptimized to avoid ventilation problems For example thesimultaneous mining of multiple middle segments results inproblems such as changes in the working surface difficultyin providing proper airflow the continuous extension of

mine ventilation lines the accumulation of waste rock in theventilation tunnels and the ventilation issues caused by theaccumulation of wastewater In addition the airflow volumeis affected by increased resistance lack of planning for theextraction of a large number of goafs without timely fillingand closing and the increase in the number of crossroadslanes caused by wind air leakage and short circuits

222 Insufficient Power of Ventilation Equipment evolume of the airflow at the mining face and driving face ofthe underground mine depends on the capacity of theunderground ventilation fans In many mines the ventila-tion capacity of the underground ventilation equipment isincompatible with the mine ventilation system and this isa common problem in underground mining As a result thelack of fresh air affects the safety of the workers

With the continuous expansion of underground miningthe number of downhole mining operations is also in-creasing this requires an expansion of the ventilation re-quirements of the working surface and in many cases theunderground ventilation network is insufficient which re-sults in poor ventilation e existing wind turbine equip-ment does not have the capacity to supply sufficient airflowand the increased temperatures and sewage gases seriouslyaffect the physical and mental health of the staff Accordingto statistics [29] the average power consumption of mineventilation equipment accounts for about 30 of the totalelectricity consumption of the mine In order to ensure theeconomic and efficient operation of ventilation fans thecapacity of the ventilation equipment and the number andlocation of the fans have to be adjusted to the requirementsto reduce the operating costs and ensure adequate airflow

223 Misalignment of Ventilation Structures e ventila-tion equipment the ducts barriers and the adjustment ofthe ventilation equipment play important roles in the reg-ulation of the airflow in the mine Ventilation structures fallinto two categories based on the airflow e first type ofventilation structure allows the airflow to pass through andthis structure includes an air inlet an air deflector and an airbridge In the second type of structure the airflow is notpassing through the system and those components includedampers air curtains air walls and wellhead closures [24]e main function of ventilation structures in undergroundmines is to ensure the flow of fresh air so that all workingsurfaces in the underground wells are reached

In many underground ventilation systems the structuresare installed improperly or components are missing whichaffects the underground airflow negatively and results indifficulties in regulating the airflow and poor ventilationCommon problems encountered inmine ventilation systemsinclude the low quality of ventilation structures which leadto air leakage short circuits and a reduction in the airflowcapacity e structures are affected by the blasting vibra-tion transport equipment and malfunctions In some casesdaily maintenance of the facilities is not performed and theregulations are disregarded erefore in order to ensurethe stable operation of the underground mine ventilation


system the layout of the ventilation equipment should bewell planned e maintenance and management of themine ventilation equipment should be regulated to ensuresucient underground fresh airow

3 Refrigeration and Cooling System withAuxiliary Cooling of Mine Water Source

In the natural environment water sources such asgroundwater surface water and atmospheric precipitationcause water inow or water seepage during the mining andproduction process in underground mines Mine waterinux exists in most underground mines In order to makefull use of the natural cold energyheat energy contained inthe underground water source we can extract heat fromdeep well and high-temperature water [30] and extract coldenergy from shallow low-temperature water [31 32] to makeuse of it e use of mine water for this purpose can becategorized based on the amount of the inow water intohigh medium and low e cooling principle is based on the

fact that the mine water is a source of cold energy that can beused in a downhole centralized cooling system An exampleof an extraction system to extract the cold energy from thewater and use the principle of heat exchange to reduce thehigh air temperatures on the operating surface is shown inFigure 2

e cooling system that uses themine inow or seepage asthe cold source includes three parts the cooling source re-frigeration and cooling e core component is the coolingsource which provides a continuous cooling capacity for therefrigeration unit and for air conditioning is technologycan be used to produce chilled water in the air cooler toachieve a heat exchange and cool the operating surface

e process of extracting cold from mine water a waterpump is used to pump the low-temperature water from theunderground ree ltration systems and a simple coarselter are used to lter the corrosive water that is moved fromthe source to the cooling station through three antiheatsystems from high pollution high ore cooling and corrosivemine water At the same time the initial high pressure of the

Minewater

Waterstorage

Heatexchanger

Waterpump

Waterpump

Cooling andreverse Kano cycle

Condenser

rottle

Evaporator

Compressor

Mine windflow

Air cooler

High-temperature airflow

Low-temperatureairflow

Low-temperaturefrozen water

Working face

Bathing heating

Figure 2 Cooling system of mine water as cold source


water is reduced when it enters the cooling system to reducethe damage to the system

e process of producing cryogenic water the re-frigeration cooling system consists of a condenser a throttlevalve an evaporator and a four-part compressor ecooling principle is based on the reverse Carnot cycle(Figure 2) and evaporation endothermic cooling e reverseCarnot cycle consists of two isothermal processes and twoisentropic processes During the cycle the cooling of thework surface is achieved by evaporation heat absorptionand condensation of the refrigerant in the circuit resultingin heat release e detailed process of the circulation systemis as follows the refrigerant is condensed into a liquid stateby using the cold mine water extracted from the un-derground storage tank en the liquid refrigerant whosepressure and temperature are lowered by the throttle valvedevice ows into the evaporator e evaporator absorbs theheat from the high-temperature mining operation surfaceand the water evaporates During this process the liquidrefrigerant is vaporized from the high-temperature back-water on the working surface and releases the cold energy e refrigerant is compressed resulting in high temperatureand high pressure of the vapor refrigerant Finally the steamrefrigerant is liqueed by low-temperature mine water in thecondenser e high-temperaturemine water can be used forunderground bathing water and heating to improve theenergy recycling

e cooling process on the high-temperature workingface is explained as follows after the chilled water istransported to the air cooler on the working surface of thedownhole by an insulated duct the high-temperature air istransported to the air cooler by a blower for the heat ex-change with the chilled water On the high-temperatureworking surface an air exchange occurs and reduces thetemperature and humidity of the ambient air in the workingenvironment

4 Practical Application and Analysis

41 Project Overview e study area is located in thewestern section of the Great Lakes Valley in Yangping TownLingbao City Henan Province the gold deposit is located inthe northern part of the Laojiachac complex anticline in theXiaoqinling Mountains e syncline axis of the Xiyin-LeijiaPass runs through the northern part of the mining area eterrain is comprised of low elevations in the south and highelevations in the north e 1118m deep pit mine at theJinqu Gold Mine is currently under construction for ex-ploration and infrastructure development e pioneeringmethod used in this mine pit excavation is the joint de-velopment of a blind shaft a pit and an incline the area isdominated by excavation e middle section of the 1118mdeep pit mine which is currently being mined consists ofsections at the depths of 640m 830m 696m 597m 440mand 280m emidsections at 440m and 280m are the mainopen mining areas at this time [33] e mining operationdetails are shown in Figure 3 e ventilation system of the1118m pit mine in Jinqu Gold Mine adopts single-wingdiagonal extraction mechanical ventilation and the localface of the tunnel is adopted with the local fan pressurizationventilation At the 640m level a mine fan withmodel K40-4-1490 and rated power of 90 kW is installed as the main fanof the ventilation system e amount of airow in the mainventilation shaft of the 1118m underground pit ventilationsystem in Jinqu Gold Mine is shown in Table 1

e depth of the 280mmiddle working surface is as highas 838m e large depth of the undergroundmine results inhigh temperatures of the surrounding rocks in the exca-vation tunnel is heats the air in the tunnel and createsa high-temperature working environment by long-distanceheat conduction or convection e large wind resistancegenerated by the ventilation line and the high airowpressure causes low wind speeds in the ventilation ducts in

1118 m pit

640 m640 m

830 m

950 m pit725 m return air grille

440 m597 m

280 m

Blind sha

696 m

1250 m return air grille

Inlet airwayReturn airway

Figure 3 Current status of exploitation in Jinqu Gold Mine


the middle section at 280m e seepage or inflow of waterin the roadway accelerates the evaporation of the high-temperature environment and increases the humidity eoperational environment of high temperatures high hu-midity and low wind speeds in the middle section of the280m site has caused serious harm to the undergroundworkers and this problem has to be addressed

42 Calculation of Heat Dissipation and CoolingLoad of Roadway

421 Heat Release of Surrounding Rock in Well In themiddle section of the 280m pit the surface temperature ofthe surrounding rock of the horizontal mining roadway is inthe range of 35ndash39degC because this area is located at a depth of838m e average wind speed is 28ms the distance fromthe exit of the ventilation equipment to the work surface is15mndash20m the cross section of the roadway is 75m2 theperimeter of the roadway is 116m the average air tem-perature in the west wing roadway is 332degC and the ex-pected temperature after cooling is about 28degC e heatexchange between the high-temperature surrounding rockand the air in the tunnel is the cause of the high temperatureof the 280m horizontal roadway e roadway circumfer-ence was calculated using the relevant parameters of the280m horizontal roadway and (1) and (2) e heat dissi-pation of the rock is defined as follows

Qr KτUL trm minus t( 1113857 1163

((196 times 28) + 00441)times 116

times 18 times(37minus 28)

1000 2688 (kW)

(11)

According to the relevant data from the mine pitmonitoring at 1118m of Jinqu Gold Mine and (3) (4) and(5) the heat absorbed by the latent heat in themine airflow is1782 kW

422 Heat Dissipation of Electromechanical Equipmente degree of mechanization of the mining face at the 280mlevel roadway tunnel is relatively high and the heat emitted

by the electromechanical equipment during normal oper-ations accounts for a large part of the heat of the miningoperation surface e excavation work requires mechanicaland electrical equipment including three YT28 rock drillingmachines with a power of 08 kW a rake loader with a modelof P-30 and power of 188 kW one DBKJNO-62times15 kWcounter-rotating local fan pressure inlet and withdrawablefan each and transport equipment with a power of 40 kWAnd mining equipment was calculated using the equipmentspecification and (6)

Qd 1113944 φNd 3 times 08 times 06 + 188 times 04

+ 2 times 15 times 03 + 40 times 02 2596 (kW)(12)

423 Heat Dissipation of Ore in Transportation etransportation of the ore results in increases in the heat asthe ore cools during transport and contributes to the high airtemperatures in the roadway According to existing recordsthe amount of ore transported per unit time is 8 kgs elength of the roadway for a single-head tunnel is 650m einitial rock temperature of the mining face is 37degC on av-erage e average wet-bulb temperature in the roadway is333degC According to (7) the heat dissipation of the trans-ported ore is

Qk 00024L08

tr minus twm( 1113857mCm 00024 times 65008

times(37minus 333) times 8 times 097 1226 (kW)(13)

424 Heat Energy Release due to Air Pressure Differencese vertical distance between the 1118m deep pit and the280m horizontal working face in the Jinqu Gold Mine is838m If we assume adiabatic conditions the air temper-ature rises by about 1degC for every vertical downward flow of102m e results show that the heat released due to the airpressure difference is significantly lower than that of the welle warming of the air has a certain influence As the airflows downward towards the working surface the hightemperature results in thermal expansion of the air andreduces the density of the air Based on the given parametersthe mass flow rate G of the air is 27 kgs e heat releaseddue to the air pressure differences can be obtained using (10)

Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)

425 Calculation of Required Cooling Capacity e re-quired cooling load for minimizing the thermal damage inunderground mines usually refers to the required coolingcapacity of the working areas such as the mining operationsurface and the chamber In this study the 280m horizontalwest wing heading face is used as an example to calculate therequired cooling capacity of the heading face the mass flowrate of the air at the exit of the wind tunnel is 53 kgs and theflow rate is relatively stable A wind turbine failure wasignored here e required cooling capacity of the workingarea is calculated using the following equation

Table 1 Air volume of underground ventilation shaft in 1118m pitof Jinqu Gold Mine

Ventilation tunnel Air volume(m3s)

Air speed(ms)

1118m pithead inlat air tunnel 223 21Blind shaft entry 215 24640m level main air tunnel 211 23640m level leading to the mainreturn air tunnel 183 34

440m inclined shaft airway 54 12440m level return air well 52 21440m level working face 02 007280m inclined shaft airway 0 0280m level return air well 0 0280m level working face 01 005


Qcooling geG h2 minus h1( 1113857 + 1113944 Qheating (15)

where Qcooling is the required cooling capacity of the exca-vation work surface G is the quality of the airflow at the coldlocation h2 is the enthalpy of the wind at the cold locationh1 is the enthalpy of the wind at the cool-down destinationand 1113936 Qheating is the total surface heat e hottest dry-bulbtemperature of the air at the 280m horizontal heading face is346degC and the humidity is greater than 90 If the dry-bulbtemperature is 28degC the unit mass enthalpy is 306 kWHowever in engineering practice it is often necessary toincrease the safety factor to prevent the loss of the coolingcapacity during transportation As a result the coolingcapacity of the work surface is insufficient and is generallyabout 12 Equation (15) is used to calculate the requiredcooling capacity of the working surface of the head

Qcooling ge 12 times[53 times 306 +(265 + 1226 + 2596

+ 2688 + 1782)] 2973 (kW)(16)

erefore the required cooling capacity of the 280mmiddle-end heading face is 2973 kW

43 Optimization of Underground Ventilation System andEffect Analysis

431 Ventilation Network Optimization e current ven-tilation system in the 1118m pit mine in the Jinqu GoldMine is optimized with regard to the ventilation line net-work layout and broken area of ventilation tunnel andconsists of the following improvements (1) reasonablyoptimizing downhole ventilation line expanding 280mhorizontal diameter 025m air return guide hole diameterinto 14m air return well form 280m level and 640mhorizontal airflow loop and promoting natural wind cir-culation at 280m level (2) optimizing the effective flowsection of airflow clearing the waste rock and sewage ac-cumulated in the ventilation tunnel in time increasing theeffective ventilation area of the ventilation tunnel ensuringthe smooth flow of the downhole and reducing the venti-lation resistance

432 Ventilation Equipment e fans are importantcomponents of the downhole ventilation system becausethey draw the air into the mine e fans are importantcomponents of the downhole ventilation system becausethey draw the air into the mine e following midsectionfan optimization and improvement measures are imple-mented (1)e existing two wind turbines with a power of11 kW which were used for supplying air to the mid-section of the 280m section are replaced with two windturbines with a combined power of 21 kW to increase theblowing power e radial distance between the blades ofthe fan is equipped with a special diffuser (2) e size andmaterial of the air duct are changed by replacing the unitwith a diameter of 300mm with a rigid air duct with thediameter of 500mm to reduce the wind resistance (3) Inthe middle of the 280m section a series-connected 11 kW

axial fan was added to pressurize the relay It is worthnoting that when adjusting the fan power it must beensured that the ingoing fan power is less than the out-going fan power

433 Optimization of Ventilation Structure e optimi-zation of the downhole ventilation structures consists of thefollowing improvements (1) A damper is installed at theopening of the ventilation roadway leading to the 830mdeep mining area in the middle section of the 640m sectionto prevent the fresh airflow (2) A controllable and adjustablemine ventilation window is installed in the 640m middlesection of the 640mndash440m inclined shaft to allow a suffi-cient amount of fresh air to flow smoothly to the middle ofthe 440m and 280m middle sections

434 Analysis of Implementation Effect of Ventilation SystemReform Project e 1118m pit ventilation system of JinquGold Mine has been rebuilt over a period of more than sixmonths and the optimization of the ventilation system hasbasically been completed Compared with the originalventilation system the advantages of the existing ventilationsystem are mainly reflected in the following aspects (1) e280m return air guide hole with a horizontal diameter of025m has become a 14m diameter return air well whichpromotes the circulation of 280m horizontal natural windcurrents (2)e parameters of the main fan of the mine andthe radial spacing of the blades have been optimized whichhas increased the total intake air volume of the mine (3)eair duct leading to the single-headed excavation work sur-face is replaced with a diameter of 300mme rigid air ductmade of a material reduces the ventilation resistance of theairflow (4) Abandoned roadway of downhole ventilationsystem has been closed which solved the phenomenon ofdownhole airflow short circuit and fresh airflow loss in theoriginal ventilation system (5)e installation of ventilationstructures in the downhole ventilation system is added thetrend of the downhole air flow is reasonably adjusted the airvolume is allocated on every job surface in accordance withthe demand and the waste or shortage of fresh air flow in theunderground is avoided e results of the actual mea-surement of the air volume at each level and on the workingsurface after the optimization of the underground mineventilation system are compared with those before thetransformation are shown in Table 2

44 ermal Damage Control Cooling Technology In thisstudy we designed a cooling system for the 640m middlesection using cold mine water as a source for the heattreatment of the 280m horizontal working face of the1118m deep pit in the Jinqu Gold Mine e details of thedownhole centralized cooling system and the process areshown in Figure 4

(1) e water storage tank at the 640m level is used asthe cooling source of the downhole cooling system Afiltration system is used at the cooling water pumpstation to filter out the impurities in the gushing


water and the cold water is then pumped to the440m level to the heat exchange station

(2) ree heat exchange systems are installed at the440m level to preliminarily purify the highly pol-luted and highly mineralized inflow water extractthe cold energy to be sent to the refrigeration unitand convert the water pressure e high waterpressure caused by the difference in the height of thewater source and destination is converted to lowwater pressure to reduce damages to the pipeline andthe refrigeration unit

(3) In the 440m horizontal return-ventilation wellscooling chillers are set up to further cool the chilledwater which is supplied to the air cooler at the 280mhorizontal mining surface

(4) e air cooler at the 280m level precools the airflowing through the air cooler using the chilled waterso that the low-temperature air flows to the worksurface and exchanges the heat with the high-temperature air on the work surface to cool thework surface

45 Analysis of Practical Application After the imple-mentation of the heat damage control and cooling measuresat the 1118m pit mouth and 280m horizontal high-temperature working surface of the Jinqu Gold Mine tak-ing the 280m horizontal west wing working surface as anexample the temperature and humidity of the underground280m level working environment were analyzed using thecomparative analysis method e layout of the monitoring

Table 2 e measured air volume of main roadway before and after transformation of ventilation system

Ventilation tunnel Preoptimized air volume(m3s)

Optimized air volume(m3s)

Changing of air volume(m3s)

1118m pithead inlet air tunnel 223 370 +157Blind shaft entry 215 363 +148640m level main air tunnel 211 351 142640m level leading to the main return air tunnel 183 121 minus68440m inclined shaft airway 54 225 +174440m level return air well 52 102 +54440m level working face 02 29 +27280m inclined shaft airway 0 68 +68280m level return air well 0 62 +62280m level working face 01 30 +29

1118 m ground

Mine water Bath water 640 m level

Three-party heatexchange system

Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment

The west wingworking face Mine ventilator

Figure 4 Design of cooling system for 1118m pit in Jinqu Gold Mine


points is shown in Figure 5 e temperature and humidityof the air near the monitoring points are shown in Table 3

Figure 6 shows the cooling eect at the monitoringpoints at the 280m horizontal west wing driving headthrough which the low-temperature airow is directly sentto the working face of the driving head e temperature ofthe working face is 327degC prior to cooling and 276degC aftercooling with a cooling rate of 51degC Prior to the imple-mentation of the cooling measures the relative humidity inthis location was as high as 90 after cooling the relativehumidity is 76 and the dehumidication amplitude is 14

5 Concluding Remarks

(1) Based on the analysis of traditional cooling tech-nology in underground mines a downhole coolingsystem using mine water as the cooling source isproposed By using the natural sources of low-temperature water inltration or seepage in un-derground mines the operating costs of the coolingsystem are reduced In addition the use of inowwater also solves the problem of heat condensationand cooling system emissions and reduces the oc-currence of underground thermal damage

(2) e underground ventilation system and operatingprocedures were optimized which improved theairow and volume in the underground mining areas e results of the optimization and reconstructionshow that the eective air volume of the west wingin the 280m midsection increased from 09m3sprior to the optimization to 32m3s after the op-timization this improved the working environmentin this area

(3) A heating and cooling system using cold mine inowwater was built in the Jinqu Gold Mine e 280mmiddle working face was treated for thermal damage e practical results showed that the temperature onthe working face of the west wing target area wasmaintained at 28degC the temperature of the headingface was reduced by 54degC and the relative humidityon the working face was reduced by 15 e resultsdemonstrate the positive eects of the cooling systemon the environmental conditions in the mine

Data Availability

e experimental data listed in this paper are measuredand obtained from the Jinqu Gold Mine in Henan Prov-ince China e temperature humidity and wind speed of

Table 3 Temperature and humidity monitoring data before andafter cooling

Monitoringpoint

Temperature (degC) Relative humidity ()Aftercooling

Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H

The scopeof workingEntrance

D E F

200 m 400 m 600 m

Figure 5 Layout of measuring points in the west tunnel of themiddle section of 280m

323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)

FEB CA G --D HMeasuring point

Before coolingAer cooling

(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)

FEB C GA --D HMeasuring point


(b)

Figure 6 Comparison of temperature and humidity on theworking face (a) Before operation (b) After operation


various monitoring points are measured in the downholeworking environment over a period of one monthbeforeafter the optimization of the ventilation and heatdamage controle optimization of ventilation and thermalhazard control techniques in the paper can be applied tounderground mines with similar problems e data used tosupport the findings of this study are available from thecorresponding author upon request

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

is work was supported by 15JK1414 (Special ScientificResearch Project of Shaanxi Provincial Education De-partment titled ldquoeoretical research on temporal andspatial 4D information model construction of open pitminerdquo) and 2016JM5088 (Foundation Project of NaturalScience Foundation of Shaanxi Province titled ldquoeoreticalstudy on temporal and spatial deduction model of miningproduction information in open pit minerdquo)

References

[1] H P Xie H W Zhou D J Xue et al ldquoResearch and con-sideration on deep coal mining and critical mining depthrdquoJournal of China Coal Society vol 37 no 4 pp 535ndash542 2012

[2] J X Lai X L Wang J L Qiu J X Xie and Y B Luo ldquoAstate-of-the-art review of sustainable energy based freezeproof technology for cold-region tunnels in Chinardquo Renew-able and Sustainable Energy Reviews vol 82 pp 3554ndash35692018

[3] J X Lai X L Wang J L Qiu et al ldquoExtreme deformationcharacteristics and countermeasures for a tunnel in difficultgrounds in southern Shaanxi Chinardquo Environmental EarthSciences 2018 In press

[4] W H Zhou H Y Qin J L Qiu et al ldquoBuilding informationmodelling review with potential applications in tunnel en-gineering of Chinardquo Royal Society Open Science vol 4 no 8pp 170ndash174 2017

[5] M C He and P Y Guo ldquoDeep rock mass thermodynamiceffect and temperature control measuresrdquo Chinese Journal ofRock Mechanics and Engineering vol 32 no 12 pp 2377ndash2393 2013

[6] A P Sasmito J C Kurnia E Birgersson andA S Mujumdar ldquoComputational evaluation of thermalmanagement strategies in an underground minerdquo Appliedermal Engineering vol 90 pp 1144ndash1150 2015

[7] J X Lai H Zhou K Wang et al ldquoShield-driven inducedground surface andMing Dynasty city wall settlement of Xirsquoanmetrordquo Tunnelling and Underground Space Technology 2018In press

[8] J L Qiu Y L Xie H B Fan Z C Wang and Y W ZhangldquoCentrifuge modelling of twin-tunnelling induced groundmovements in loess stratardquo Arabian Journal of Geosciencesvol 10 no 22 p 493 2017

[9] J L Qiu X L Wang S Y He H Q Liu J X Lai andL X Wang ldquoe catastrophic landside in Maoxian County

Sichuan SW China on June 24rdquo Natural Hazards vol 89no 3 pp 1485ndash1493 2017

[10] J X Lai S Y He J L Qiu et al ldquoCharacteristics of seismicdisasters and aseismic measures of tunnels in Wenchuanearthquakerdquo Environmental Earth Sciences vol 76 no 2pp 76ndash94 2017

[11] J X Lai S Mao J L Qiu et al ldquoInvestigation progresses andapplications of fractional derivative model in geotechnicalengineeringrdquo Mathematical Problems in Engineeringvol 2016 Article ID 9183296 15 pages 2016

[12] S R Hu J C Peng C Huang et al ldquoAn overview of currentstatus and progress in coal mining of the deep over a kilometerrdquoChina Mining Magazine vol 20 no 7 pp 105ndash110 2011

[13] H Y Qu H W Liu R F Pei et al ldquoGeochemical charac-teristic overview of the Shizishan ore-field at Tongling cityAnhui province Chinardquo Contributions to Geology andMineral Resources Research vol 26 no 3 pp 239ndash248 2011

[14] C Q Cheng L B Dong and S D Xu ldquoSimulation andoptimization of deep stope mining sequence in hongtoushancopper minerdquo Metal Mine vol 9 pp 66ndash68 2016

[15] M Asghari P Nassiri M Reza Monazzam et al ldquoWeightingcriteria and prioritizing of heat stress indices in surfacemining using a Delphi technique and fuzzy AHP-TOPSISmethodrdquo Journal of Environmental Health Science and En-gineering vol 15 no 1 pp 1ndash11 2017

[16] J L Qiu X L Wang J X Lai Q Zhang and J B WangldquoResponse characteristics and preventions for seismic sub-sidence of loess in Northwest Chinardquo Natural Hazardsvol 92 no 3 pp 1909ndash1935 2018

[17] J L Qiu H Q Liu J X Lai et al ldquoInvestigating the long termsettlement of a tunnel built over improved loessial foundationsoil using jet grouting techniquerdquo Journal of Performance ofConstructed Facilities vol 42 no 5 pp 112ndash134 2018

[18] S Mahdevari K Shahriar and A Esfahanipour ldquoHumanhealth and safety risks management in underground coalmines using fuzzy TOPSISrdquo Science of the Total Environmentvol 488-489 pp 85ndash99 2014

[19] H N Wang J L Peng and Z Cheng ldquoAnalysis of ventilationand cooling in high temperature minerdquo Nonferrous MetalsEngineering vol 3 no 3 pp 34ndash37 2013

[20] Y P Yuan X K Gao H W Wu et al ldquoCoupled coolingmethod and application of latent heat thermal energy storagecombined with pre-cooling of envelope method and modeldevelopmentrdquo Energy vol 119 pp 817ndash833 2017

[21] P Y Guo and C Chen ldquoField experimental study on thecooling effect of mine cooling system acquiring cold sourcefrom return airrdquo International Journal of Mining Science andTechnology vol 23 no 3 pp 453ndash456 2013

[22] B B Shi L J Ma W Dong and F B Zhou ldquoApplication ofa novel liquid nitrogen control technique for heat stress andfire prevention in underground minesrdquo Journal of Occupa-tional and Environmental Hygiene vol 12 no 8 pp 168ndash1772015

[23] P Y Guo M C He L G Zheng and N Zhang ldquoA geo-thermal recycling system for cooling and heating in deepminesrdquo Applied ermal Engineering vol 116 pp 833ndash8392017

[24] H N Wang B Peng J L Peng et al ldquoAnalysis of commonlyexisting ventilation problems and the optimal approach todeal with them in large-size minesrdquo Journal of Safety andEnvironment vol 14 no 3 pp 24ndash27 2014

[25] S H Zou K Q Li D C Zhang et al ldquoOn the air-partition foecooling with the heat-insulated platerdquo Journal of Safety andEnvironment vol 16 no 2 pp 99ndash102 2016


[26] Y C Zhang ldquoResearch on treatment technology and coolingeffect of thermal damage in Zhuji coal minerdquo Safety in CoalMines vol 46 no 10 pp 157ndash159 2015

[27] C B Wang ldquoHeat analysis and initial mining surface airtemperature prediction research on Gaojiapu coal minerdquoCoalTechnology vol 35 no 11 pp 210ndash212 2016

[28] Z X Li T M Wang M Q Zhang et al ldquoConstruction of airflow heat transfer coefficient and calculation of airflowtemperature in mine wet roadwayrdquo Journal of China CoalSociety vol 42 no 12 pp 3176ndash3181 2017

[29] S B Yin R H Shu and M L Zhang ldquoApplication of themining ventilation system optimization by using equilibriumdiagram adjustment method based on the principle of min-imum energyrdquo Journal of Safety and Environment vol 16no 5 pp 120ndash124 2016

[30] S Jardon A Ordontildeez R Alvarez P Cienfuegos andJ Loredo ldquoMine water for energy and water supply in thecentral coal basin of Asturias (Spain)rdquo Mine Water and theEnvironment vol 32 no 2 pp 139ndash151 2013

[31] A P Athresh A Al-Habaibeh and K Parker ldquoe design andevaluation of an open loop ground source heat pump oper-ating in an ochre-rich coal mine water environmentrdquo In-ternational Journal of Coal Geology vol 164 pp 69ndash76 2016

[32] J Sivret D L Millar and G Lyle ldquoConceptual overview andpreliminary risk assessment of cryogen use in deep un-derground mine productionrdquo IOP Conference Series Mate-rials Science and Engineering vol 278 pp 1ndash8 2017

[33] X X Nie and X B Wei ldquoOptimization and practice on thereform schemes of ventilation system in the Jinqu GoldMinerdquo Mining RampD vol 37 no 8 pp 86ndash89 2017


International Journal of

AerospaceEngineeringHindawiwwwhindawicom Volume 2018

RoboticsJournal of

Hindawiwwwhindawicom Volume 2018


Active and Passive Electronic Components

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawiwwwhindawicom

Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Control Scienceand Engineering

Journal of



Journal ofEngineeringVolume 2018

SensorsJournal of



RotatingMachinery


Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation


Hindawi

wwwhindawicom Volume 2018

Advances in

Multimedia

Submit your manuscripts atwwwhindawicom

production eciency of deep mine operating surfacesand contribute to the exploitation of mineral resourcesrich in the depth of the Earth

High-temperature thermal damage in undergroundmines can be minimized by nonarticial refrigerationcooling and articial refrigeration cooling Common non-articial refrigeration cooling methods include ventilationcooling heat insulation and personal protection Commonarticial cooling methods include water cooling ice coolingand thermoelectric cooling combined with cogenerationHowever nonarticial refrigeration cooling methods cannotbe applied in deep mines to minimize high temperatures dueto the limitations in the cooling capacity Yuan et al [20]proposed a new coupled cooling method of Latent Heat ermal Energy Storage (LHTES) combined with Pre-cooling of Envelope (PE) Guo and Chen [21] used thedeep well return air as the cold source of the cooling systemto achieve cooling and dehumidication on the workingsurface Shi et al [22] used liquid nitrogen to inject into theworking face to achieve cooling eect Guo et al [23] usedthe heat of the bathing water on the surface and createda refrigeration unit to achieve a heat exchange between thechilled water and the high-temperature air on the workingsurface the heat created by the condensation of the re-frigeration unit was recovered and the thermal hazard of thehigh temperatures in the mine was converted into heatenergy thereby improving the energy eciency Wang et al[24] optimized a ventilation system and increased theventilation of a mine and the distribution of the air vol-ume to accelerate the downhole airow to achieve cooling

Zou et al [25] used the theories of uid mechanics and heattransfer to develop heat insulation materials in the minemain ventilation tunnel to achieve heat insulation heatremoval and cooling Zhang [26] used combined heat andpower cogeneration technology using steam lithium bro-mide chillers and centrifugal chillers for heating powergeneration and refrigeration to improve the energy utili-zation In this study we propose a downhole centralizedcooling system using mine water as the cooling source witha focus on underground mines with inow water or waterseepage e method is based on the principle of heat ex-change between the cold mine water and the high airtemperatures of the working area and minimizes the heatdamage in the working area e cooling system assisted bymine water source cooling is to reduce the output of re-frigeration unit cooling capacity by using the cold energyhidden by the groundwater source to save the running costof cooling and cooling system In addition the condensingheat discharged by the cooling and cooling system can beabsorbed by the cold energy contained in the mine watersource itself reducing the emission of condensation heat andreducing the secondary thermal hazards generatedunderground

2 Thermal Damage Analysis ofHigh-Temperature Mine

e related research shows that the fundamental cause of thehigh-temperature heat damage near the working face of themine is the concentration of the heat on the working surface

Eastern north heat damageEastern heat damageEastern south heat damage

Figure 1 Distribution map of high-temperature mine in deep mining in China






Kτ 1163

196vB( 1113857 + 00441 (2)




β 00846 + 00262vB (4)

kB 101325

B (5)




Qd 1113944 φNd (6)




Qk 00024L08






427GminusG

ω22 minusω2

12 times 427


(8)



G i2 minus i1( 1113857 ΔZ427




Qheating ΔZ427

G (10)

















Minewater

Waterstorage

Heatexchanger

Waterpump

Waterpump


Condenser

rottle

Evaporator

Compressor

Mine windflow

Air cooler




Working face

Bathing heating









1118 m pit

640 m640 m

830 m


440 m597 m

280 m

Blind sha

696 m









((196 times 28) + 00441)times 116


1000 2688 (kW)

(11)







Qk 00024L08




Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)




Air speed(ms)







+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia






Kτ 1163

196vB( 1113857 + 00441 (2)




β 00846 + 00262vB (4)

kB 101325

B (5)




Qd 1113944 φNd (6)




Qk 00024L08






427GminusG

ω22 minusω2

12 times 427


(8)



G i2 minus i1( 1113857 ΔZ427




Qheating ΔZ427

G (10)

















Minewater

Waterstorage

Heatexchanger

Waterpump

Waterpump


Condenser

rottle

Evaporator

Compressor

Mine windflow

Air cooler




Working face

Bathing heating









1118 m pit

640 m640 m

830 m


440 m597 m

280 m

Blind sha

696 m









((196 times 28) + 00441)times 116


1000 2688 (kW)

(11)







Qk 00024L08




Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)




Air speed(ms)







+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



427GminusG

ω22 minusω2

12 times 427


(8)



G i2 minus i1( 1113857 ΔZ427




Qheating ΔZ427

G (10)

















Minewater

Waterstorage

Heatexchanger

Waterpump

Waterpump


Condenser

rottle

Evaporator

Compressor

Mine windflow

Air cooler




Working face

Bathing heating









1118 m pit

640 m640 m

830 m


440 m597 m

280 m

Blind sha

696 m









((196 times 28) + 00441)times 116


1000 2688 (kW)

(11)







Qk 00024L08




Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)




Air speed(ms)







+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia








Minewater

Waterstorage

Heatexchanger

Waterpump

Waterpump


Condenser

rottle

Evaporator

Compressor

Mine windflow

Air cooler




Working face

Bathing heating









1118 m pit

640 m640 m

830 m


440 m597 m

280 m

Blind sha

696 m









((196 times 28) + 00441)times 116


1000 2688 (kW)

(11)







Qk 00024L08




Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)




Air speed(ms)







+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia








1118 m pit

640 m640 m

830 m


440 m597 m

280 m

Blind sha

696 m









((196 times 28) + 00441)times 116


1000 2688 (kW)

(11)







Qk 00024L08




Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)




Air speed(ms)







+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia






((196 times 28) + 00441)times 116


1000 2688 (kW)

(11)







Qk 00024L08




Qheating ΔZ427

G 838427

times 05 times 27 265 (kW) (14)




Air speed(ms)







+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia





+ 2688 + 1782)] 2973 (kW)(16)





















1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia












1118 m ground



Refrigeration unit

Air cooler

440 m level

280 m level

Watercatchment










Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia








Data Availability



Monitoringpoint


Beforecooling

Aftercooling

Beforecooling

A 292 323 79 92B 295 329 81 95C 301 335 83 94D 299 339 86 97E 292 341 84 95F 286 337 84 93G 281 332 80 92H 276 327 76 90

A B GC

100 m 300 m 500 m

H


D E F

200 m 400 m 600 m


323329

335 339 341 337332 327

292 295301

292299

286 281 276

20

22

24

26

28

30

32

34

Tem

pera

ture

(degC)



(a)

92

9597

93 9290

94

7981

83

8684 84

80

76

95

70

75

80

85

90

95

100

Relat

ive h

umid

ity (

)



(b)






Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia





Acknowledgments


References







































RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia













RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia


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