energy recovery: saving energy in industrial...
TRANSCRIPT
Energy Recovery: Saving Energy in Industrial Applications
Juan Manuel Moreno, LEED AP Project Manager Eaton’s Energy Solutions, Inc.
It’s rough recovering energy….
How I Hope to Keep You In This Room!!
• Industrial Energy Consumption in the USA • Fundamentals of Energy Recovery • Advantages of Energy Recovery in Industrial Processes • Boiler Flue Gas Energy Recovery • Gas Driven Chillers • CHP and CCHP • Energy Recovery With Heat Pumps • Desuperheaters • Energy Recovery with Organic Rankin Cycle
Industrial Energy Use in the U.S.
• Total industrial energy consumption = 30.6 quads • Approximately 55% for power & heat = 15.3 quads • 10-20% is avoidable waste • Approximately $6.00 per million Btu • $9.18 to $18.36 Billion Approximate Value of Waste
Fundamentals of Energy Recovery
Process that transfers waste energy of a system to the input material flow of the
same system or its surroundings
The waste energy has been paid for
Sensible and/or latent heat recovery is possible
User consumes the recovered energy as part of its process
Q = m Cp DT
Advantages of Energy Recovery in Industrial Processes
Advantages of Energy Recovery in Industrial Processes
High coincidence between cooling, heating and
electrical loads
Steam, hot water, chilled water and compressed air services required
Moderate to high operating hours >4,000 hours per year
Electric power quality and reliability are important requirements
High quality energy available
Boiler Flue Gas Energy Recovery
Flue Gas Energy Recovery
Air Recuperative Regenerative
Water Economizer Steam Generator
• Gas-to-gas heat exchanger
• Heat transfer from exhaust gas to air
• Thermal storage device • Giant heat wheel • Ovens, chemical reactors,
prime movers
• Similar to a boiler • Heat source is waste
energy from a process
• Installed in stack • Transfers waste heat to
feedwater or return water
Boiler Economizer - Application
Food manufacturing
Retrofitted a 4,000 MBH existing cast
iron hot water boiler Fuel: Propane
Total annual cost savings: $24,670 Simple Payback: 3.5 years
342 MBH recovered energy
Boiler Economizer Lessons Learned
Check existing system water conditions
• Proper oxygen levels • Check for solids, minerals and organic material
Determine if an economizer stack by-pass is required
• If economizer fails the boiler must be shut down. Is owner ok with this? • Is there a fully redundant boiler?
Can existing stack handle the additional pressure drop?
• Typical pressure drop 0.15 to 0.25 in WC
Leave enough room between boiler flue discharge and economizer for combustion ports
Gas Driven Chillers COPs between 1.8 to 2.9 with no
engine jacket heat recovery COPs between 1.9 to 3.16 with
engine jacket heat recovery Water cooled available from 150 tons
to 400 tons Air cooled available from 50 tons to
100 tons Free engine waste heat recovery
Gas Driven Chillers - Application
Food manufacturing plant
Simultaneous need for hot and
chilled water
Operation >8,000 hours per year
800 ton central chiller plant
2,600,000 KW-hr saved per year
Increase of 205,686 therms per year
$ 460,000 total cost savings per year
Simple payback 3.41 years
CHP and CCHP
Combined Heat and Power • Cogeneration • Simultaneous production of heat
and generation of electrical energy from a single fuel source
Combined Cooling Heat and Power
• Trigeneration • Simultaneous production of heat,
cooling and generation of electrical energy from a single fuel source
Benefits Increased system thermodynamic
efficiency Reduced carbon footprint Sustainable Lower total energy costs Improved power reliability and
quality
CHP and CCHP
Rules of Thumb Feasibility is high when: Cost of electrical energy above $0.06/Kwhr Greater than 5,000 hours of operation per year Simultaneous electrical and thermal energy loads
Prime Mover Selection Criteria T/E = 0.5 – 1.5 Internal Combustion Engines T/E = 1 – 10 Gas Turbines T/E = 3 - 20 Steam Turbine
CHP and CCHP Service IC
Reciprocating Engines
Gas Turbines
T/E Ratio
Hot Water 4 MBH/KW 5 MBH/KW
Steam 2 MBH/KW 5 MBH/KW
Absorption Chilled Water
0.25 TON/KW 0.35 -0.6 TON/KW
CCHP - Application
Ice manufacturing plant
Simultaneous need for electrical
and cooling load
Operation >8,000 hours per year
1.7 MW IC Gas Driven Engine
1,950,000 KW-hr saved per year
67% Annual Energy Cost Savings Simple payback 3.6 years
CCHP - Application
Ice manufacturing plant
Simultaneous need for electrical
and cooling load
Operation >8,000 hours per year
1.7 MW IC Gas Driven Engine
1,950,000 KW-hr saved per year
67% Annual Energy Cost Savings Simple payback 3.6 years
Energy Recovery With Heat Pumps
215˚F Supply air/water possible
with lower waste heat temperatures
Recover energy from chilled water central plants’ heat rejection and use for water heating, electric power generation
Recover low quality energy and boost it to higher , usable quality
Desuperheaters
Reduces refrigeration
operating costs by adding equivalent of 15% additional condenser capacity Heats water up to 180˚F
with waste heat Can be paired with other
technologies to produce higher quality energy
Energy Recovery with Organic Rankin Cycle
Waste heat to power
• Pressurized hot water • Saturated Steam • Hot gases
No emissions
Generation of up to 125KW
Heavy Industry • Glass • Cement • Chemical • Metals
Thank you!