GENERAL GUIDELINES IN HEATING

SYSTEM DESIGN IN CHINA

By Zhu Jialing

Tianjin Geothermal Research & Training

Center, Tianjin University

1. Introduction

2. Main Contents of the Standards

3. Wordage in the Standards

4. Conventional Sign Specifications of Geothermal

Utilization Engineering

5. Social and environmental Benefits

1. Introduction

In recent years, geothermal utilization technology in China has made

considerable progress. There has been created a series of new

methods of geothermal utilization through technological innovation

and process modification, improved resource utilization efficiency

and the level of technology.

The development and experience of the overall geothermal utilization

technology makes geothermal utilization in China ready for

standardized development, such as geothermal wellhead equipment,

heating systems, reinjection sytsem, hot water suppling, geothermal

network monitoring system.

It is standardization of technology as soon as possible, continuously

perfect and normalize geothermal utilization market, and will be hold

Chinese geothermal direct utilization up to world class level.

1.1 Geothermal Standards Design in Aboard

Iceland, U.S.A., Japan and Italy have a great

deal experience in geothermal utilization and

have established a perfectly standard system for

geothermal power generation and district

heating systems, covering advanced technology

and management.

1.2 Geothermal Standard Design decelopment in China

Geothermal resources are distributed widely, about 250 geothermal wells in

Tianjin. Although administrative authorities have made some supervision,

the quality and yield of geothermal wells are different and problems,

because there’ is no any regulations to follow.

This makes the geothermal heating stations dissimilar with random

installation of valves, monitoring instruments, and pipelines. The

installation not only seriously violates a number of design specifications

and requirements, but also effects the safety of operating personnel. It is

necessary to establish standards design as soonest.

1.3 Detial job on going

From 2006, The three of the guidelines are writing which orgnized

by the National Construction Department and Tianjin Geothermal

Division.

(1) The national standard “Geothermal Power Plant Design

Standard” , GB50227-200X;

(2) “Technical code for Geothermal Space Heating Engineering”,

JGJ-2008;

(3) “Geothermal Utilization Regulation (local in Tianjin)”, 2006;

The standards will improve geothermal production, environmental

protection and sustainable development of geothermal resource.

06YFGZGX02300

UDC

P JGJ 2007

Technical code for geothermal space heating engineering

2008 ― 2008

2. Main Contents of the Standards

(1) General principles and terms;

(2) Geothermal engineering surveys;

(3) Wellhead design ( pump houses, geothermal heating station units);

(4) Geothermal heating design units;

(5) Anti-corrosion and scaling;

(6) Reinjection facilities and design;

(7) Geothermal hot water supply units, and

(8) Monitoring system.

2.1 Design Codes for Geothermal Pump House

(1) Design requirements of ground pump house

a) Design drainages both of gravity and pressuring;

b) lighting and windows fixtures;

c) Regulation the lifting hole size for pump maintains.

(2) Design requirements of underground/semi-underground pump

house

a) Air intake tube and exhaust tube for safety working;

b) Regulation the lifting hole size for pump maintains and entrence;

c) Constructing an escape way.

(3) Installation requirements of wellhead equipment.

2.2 Technology of Reinjection System

1 Reinjection Technological Process, including rought filters, fine

filters, air-exhaust tank, pressuring pumps, and connections;

2 The material selection of pipes, filters;

3 The process of clearing filters;

4 The regulation of reinjection operating since the system starts to

operate;

5 The system maintains, since the system end of operating; and

6 Monitoring, such as pressure between in and out of filters,

wellhead.

2.3 Terminal Device of Geothermal Heating

1 The types of geothermal heating systems (Direct and indirect heating)

2 The Ratio of peak load over the total heat load the sources for the peak load,

such as coal, oil, gas and heat pumps, and the computing methods when the

boiler would start to operate (outdoor temp.);

3 The construction requirement of the heating station (water disposal, include

gravity and pumping, lighting, ventilate, environmental, and safety);

4 Equipments design and installation (heat exchangers, circulation pumps, water

storages, pipes, and heat pumps) ;

5 Electricity Supplying.

2.4 Anti-Corrosion and Scaling

1 The properties of geothermal fluids

The main elements to create corrosion: Cl SO-24 H2S

HS S2 NH3 CO2 O2 and pH value.

2 The methods of the anti-corrosion

a) Anti-corrosion martial be used

b) Sealing whole heating system

c) Indirect heating with heat exchangers

d) Panting a anti-corrosion chemicals to the surface of the

metal

3 The methods of anti-scaling

Anti-scaling

a) increasing pressure

b) Physical anti-corrosion (magnetization .

Removing the scaling

a) Mechanical removing

b) Hydro breaking

c) Chemicals treatments.

2.5 Technical Design for Hot Water Supplying

1 The water treatment ( Removing iron, Fe3+)

a) The limited contents of iron totally 0.3mg/l;

b) The techniques processes of iron removing from geothermal

water (oxidation processes) , operating and, protection

2 Geothermal water supply network

The type of pipe landing (a single pipe system or a double pipe

system), pipe material selection, insulations.

2.6 Monitoring System for the Geothermal Heating

1 Requirement of monitoring parameters (Temperatures, pressures,

and flow-rates);

2 Installation requirement of monitoring instruments and sencors,

such as pressure sensors)

3 Installation requirements of the signal transmission line at the plant

4 Documentations Management.

2.7 Geothermal Heating Construction, Inspection and

Acceptance

(1) Geothermal engineering quality design and construction licence

are strongly requirement. A qualified construction supervisor is

crucial for the geothermal engineering inspection;

(2) The documentations of regional exploitation, feasibility study

report, design and construction shall be addressed before;

(3) A detailed inspection of last “checkpoint” for the quality of the

geothermal engineering.

3. Wordage in the Standards

In establishing the standards, the wordage concerned in

policies, technologies and safety in clauses for the

operation and management.

3.1 Compulsory Execution and Requirements

To express very strict and must be complied with, “must”

and “strictly prohibited”, for example:

(1) Geothermal utilization efficiency in heating must be

above 65% , or utilization efficiency less than 65% are

strictly prohibited;

(2) Discharge temperature must be less than 35C.

3.2 General Requirements

To express that the wording is strict, include “should”

or “should not”, for example:

(1) Reinjected in a different formation should conform

to requirements of the local administrative authority;

(2) Open lines should not be permitted.

3.3 Suggestive Requirements

To express necessity, write in permissive condition, for example:

(1) In permissive condition, underground/semi-underground pump

houses should not be adopted;

(2) Pump house must not be built under permanent structure.

3.4 References

Other existed regulations or national standdards have been referenced

in the guidelines, such as Water Supply & Drainage Drafting

Standard (GB/T 50106-2001).

4. Conventional Sign Specifications of

geothermal Utilization Design

Geothermal Wellhead System

Equipment

Name Diagram Name Legend

Wellhead

Equipment

System Diagram

For artesian well

System Diagram

For non-artesian well

Desander System Diagram

5. Social and Environmental Benefits

The geothermal standards will be published available. It

will normalize the technology for the geothermal

utilization, improve the standardization level of

geothermal engineering, serve as a guide for high level

planning and construction, normalize the operation, and

improve the quality of geothermal construction. At the

same time, the standards will enhance the supervision of

geothermal heating and power stations.

THANK YOU!