Absorption-type heat pumps (Heat Apmlifiter Type)
Utilizing unused energy Absorption Heat-pump (Type 1: Heat Amplifier)
Due to the rising demand of reducing Carbon Dioxide; the active global warming gas to prevent global warming, various technologies are advanced to reduce energy year by year for different kinds of equipment such as heat generators and boilers, etc. However, independent equipment has its limitation, therefore to achieve CO2 reduction goal, it is essential to utilize all waste heat energy from all production facilities in factories and plants as a system.
To achieve this target, Hitachi enhances new features to its Absorption Heat-pump, enables the unit to deliver required high temperature hot water with the system that exploits well the waste heat (exhaust gas, drained water) generated from other production facilities. The system completes the favorable cycle and accomplishes the good reliability and high efficiency of factories and plants.
Absorption-type heat pump system
Absorption Heat-pump is a system to transfer heat from waste heat source to increase temperature of supplied hot water, helping in energy saving. In general process where low temperature source is used to produce chilled water, the system is called chiller system. On the other hand, in process that heat is used to generate higher temperature hot water, it is called heat-pump system. Among these heat-pump systems, when compare heat reclaimed by using absorption heat-pump and by using boiler, the additional heat (energy) required by absorption system is far less. Moreover, the absorption system can provide much high temperature hot water when compare with compressor type heat-pump system.
Outline of absorption cooling cycle
The system uses several kinds of waste heat from different kinds of machines such as electricity generators, fired heater, excess steam from steam turbine to heat up low temperature water from 30–40ºC to usable high temperature hot water of 60–95ºC.
Energy saving by utilizing waste heat, heat reclaim efficiency COP=2.3*1
Heat pump cycle (Heat Amplifier Type) fully recovers heat from waste heat source to raise temperature of warm water to high temperature hot water.
Resulting in high COP, and huge energy saving when comparing to boiler.
95ºC hot water supply is obtainable*2
As the pressure in generator does not exceed atmosphere pressure, then there is limitation in providing hot water.
The heat-pump utilizes appropriate waste heat amount to heat up low temperature hot water to high temperature of 95ºC hot water*2, contributing to less energy used.
Low pressure steam to high temperature of hot water*3
Thanks to multistage absorption heat-pump cycle, makes it even possible to heat up low pressure steam (0.2 –0.3 MpaG) to high temperature hot water, providing effectively used of energy.
Note: *1: Double effect heat amplifier COP is indicated, Single effect heat-pump’s COP is 1.7 and depends on hot water condition.
*2: In case of single effect. If double effect is used, the temperature of water supplied is 55ºC.
*3: In case of single effect.
Example of absorption-type heat pump system
Example of Absorption Heat-pump Heat amplifier type (Single effect)
Heat up cooling water of 35℃ to provide hot water for 2 different process of
1) 90℃ temperature hot water for production process and
2 60℃ temperature hot water for boiler feeding
Absorption Heat-pump Heat Amplifier Type ( Single effect )
Capacity: 1,300 kW
Steam unit cost: 3.5/kg (Boiler steam)
Operation hours per annum: 6,000 hours
Annual operating cost: Reduced by approx. 17 million yen
Example of Absorption Heat-pump Heat amplifier type (Double effect)
Heat up 40℃ warm water from electricity generator, HRSG and air compressor to 55℃ hot water for comfort air-conditioning (heating)
Heat source unit
First class absorption-type heat pumps (double-effect)
Heating capacity: 3,400kW
Steam unit price: 3.5/kg (Boiler steam)
Operation hours per annum: 3,000 hours
Annual operating cost: Reduced by approx. 30 million yen
Main track record for supplying heat pump systems
|Model||Customer||Heat source (low temperature, waste heat)||Application||Hot water temperature||Heating capacity||Year of delivery|
|Double-effect||Automotive components manufacturer||Cooling water (Compressor)||Heating comfort||40→50℃||3,256KW||1993|
|Food industry||Cooling water (Process)||Feed water for boiler||26→62℃||1,836KW||2002|
|Food industry||Cooling water (Engine)||Hot water for process||25→50℃||897KW||2003|
|Construction machinery manufacturer||Cooling water (Compressor)||Heating comfort||50→55℃||3,349KW||2004|
|Machinery||Cooling water (Engine)||Hot water for process||50→55℃||661KW||2006|
|Single-effect||Chemical industry||Cooling water (HRSG)||Feed water for boiler||50→93℃||3,190KW||1981|
|Textile industry||Cooling water (Process)||Hot water for process||54→75℃||2,343KW||1981|
|Textile industry||Drained water (Process)||Feed water for boiler||33→90℃||1,049KW||1982|
|Chemical industry||Cooling water (Process)||Hot water for process||20→65℃||1,723KW||1982|
|Steel industry||Drained water (flushing)||Feed water for boiler||20→93℃||2,430KW||1983|
|Automotive components manufacturer||Cooling water (Compressor)||Heating comfort||57→65℃||3,537KW||1985|
|Automotive industry||Waste water (Desulfurization)||Feed water for boiler||46→90℃||8,750KW||1989|
|Chemical industry||Cooling water (Process)||Feed water for boiler||20→50℃||1,274KW||2005|
|Hot water for process||60→68℃|