Lithium bromide high-temperature absorption heat pump: Coefficient of performance and exergetic efficiency

1990 ◽  
Vol 14 (3) ◽  
pp. 281-291 ◽  
Author(s):  
M. Izquierdo ◽  
S. Aroca
Keyword(s):  
High Temperature ◽  
Heat Pump ◽  
Lithium Bromide ◽  
Coefficient Of Performance ◽  
Exergetic Efficiency ◽  
Absorption Heat Pump

Modelling and performance analysis of a single stage open absorption heat pump system in aspen plus using aqueous LiBr and HCOOK: A waste moist heat recovery application

2021 ◽  
pp. 095765092110478
Author(s):  
Muhammad Kashif Shahzad ◽  
Yaqi Ding ◽  
Yongmei Xuan ◽  
Neng Gao ◽  
Guangming Chen
Keyword(s):  
Heat Pump ◽  
Heat Recovery ◽  
Process Model ◽  
Waste Heat ◽  
Lithium Bromide ◽  
Aspen Plus ◽  
Coefficient Of Performance ◽  
Water Recovery ◽  
Pump System ◽  
Absorption Heat Pump

Open absorption heat pump (OAHP) system is more viable option to recover waste heat from moist gas as compared to the traditional condensation methods. This promising technology has great potential for latent heat recovery from moist gas, drying process in paper and other industrial heating applications. This study presents the process modelling and comparative analysis of OAHP system in Aspen Plus using two different solutions by adopting part regeneration technique. The promising potassium formate-water (HCOOK/H2O) which has lower causticity, lower costs and better crystallization characteristics is used as an alternative to the caustic lithium bromide-water (LiBr/H2O) solution in this study. Process model of the system is established in Aspen Plus and, the properties validity is confirmed with published experimental and Engineering Equation Solver (EES) library data. A detailed comparative parametric study is carried out to evaluate the effect of influencing parameters on coefficient of performance (COP), water recovery (φ) and heat recovery (ζ) efficiencies. The performance of OAHP system is found to be very similar using different concentrations as 2.13 COP value for 50% LiBr/H2O and 2.19 for 70% HCOOK/H2O solution over design conditions. Similarly, φ is found to be 0.701, 0.688 while ζ as 0.716 and 0.705 for both the absorbents. Moreover, the system’s operational concentration range is 45-61.3% for LiBr/H2O and 55-82.1% for HCOOK/H2O at 135 °C regeneration heat input. Potassium formate solution having quite similar properties to the aqueous lithium bromide is also confirmed to have similar performance trends using 50% and 70% concentrations.

Effect of Operating Temperature on the Performance and Thermal Load of Water/Lithium Bromide Vapour Absorption Heat Pump in the Absence of Solution Heat Exchanger

2014 ◽  
Vol 592-594 ◽  
pp. 1510-1514
Author(s):  
S. Manu ◽  
T.K. Chandrashekar ◽  
A.J. Antony
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Thermal Load ◽  
Operating Temperature ◽  
Lithium Bromide ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Efficiency Ratio ◽  
Absorption Heat Pump

In this investigation, a thorough thermodynamic analysis of the water/lithium bromide absorption refrigeration cycle in the absence of solution heat exchanger is performed. The influence of operating temperature on the thermal loads of components, COPc (Carnot Coefficient of Performance), COPE (Enthalpy based Coefficient of Performance) and efficiency ratio (η) is studied. It is concluded that the COPc and COPE values decreases with increasing condenser and absorber temperature but increase with increasing generator and evaporator temperatures .

Performance Characteristics of a Combined Ejector-Absorption Heat Pump Using NH3-H2O

1999 ◽  
Author(s):  
D. A. Kouremenos ◽  
E. D. Rogdakis ◽  
G. K. Alexis
Keyword(s):  
Heat Pump ◽  
Gain Factor ◽  
Coefficient Of Performance ◽  
Detailed Calculation ◽  
Absorption System ◽  
Evaporator Temperature ◽  
Pump System ◽  
Heat Gain ◽  
Absorption Heat Pump ◽  
Heat Pump System

Abstract Absorption system have been investigated for many years. However, coefficient of performance COP or heat gain factor HGF for absorption systems are significantly lower than those for conventional compression systems. This has restricted their wide application. This paper discusses the behavior of mixture NH3-H2O through of an ejector, operating in an absorption heat pump system. This combination improves the performance of conventional absorption system and with the phasing out of ozone-damaging refrigerants, absorption refrigerators, heat pumps and air-conditioning now provide a potential alternative. For the detailed calculation of the proposed system a method has been developed, which employs analytical functions describing the thermodynamic properties of die mixture. The influence of three major parameters: generator, condenser and evaporator temperature, on ejector efficiency and heat gain factor of the system is discussed. Also the maximum value of HGF was estimated by correlation of above three temperatures.

A High Temperature Lift Absorption Heat Pump

1984 ◽  
pp. 142-148
Author(s):  
C. O. B. Carey ◽  
J. S. Khahra ◽  
I. E. Smith
Keyword(s):  
High Temperature ◽  
Heat Pump ◽  
Absorption Heat Pump

Secondary Fluids for GAX Absorption Heat Pump

2003 ◽  
Author(s):  
G. Anand ◽  
C. B. Panchal ◽  
D. C. Erickson
Keyword(s):  
Los Angeles ◽  
Natural Gas ◽  
Heat Pump ◽  
Performance Model ◽  
Coefficient Of Performance ◽  
Pumping Power ◽  
Ambient Conditions ◽  
Absorption Heat Pump ◽  
Heating And Cooling ◽  
Secondary Fluid

The gas-fired Generator-Absorber heat eXchanger (GAX) heat pump is being considered for space conditioning in residential and light commercial applications. In order to meet the national building codes for ammonia absorption heat pumps, a secondary fluid is used to interface with the air-coils. Proper choice of a secondary fluid maximizes the economic advantage of the GAX heat pump. The secondary fluid transfers the heating and cooling loads from the absorption heat pump to and from outdoor and indoor air-coils. The physical properties of secondary fluids influence the heat transfer performance in the heat-exchange equipment and hence the effective lift, thereby determining the cycle coefficient of performance (COP). Additionally, the pumping power for each fluid varies depending on the density and viscosity at operating temperatures. The variation in cycle COP and pumping power as a result of fluid properties is ultimately manifested as changes in electric and natural-gas cost. An analysis was carried out to evaluate six secondary fluids for a GAX absorption heat pump. A performance model was developed to simulate the secondary-fluid flow loops and the absorption heat pump. The utility costs for heating and cooling were determined for a typical building. The effects of ambient conditions and local utility rates were determined by modeling the annual utility costs in four cities: Atlanta, Chicago, Los Angeles, and New York. These four cities provided wide variations in heating and cooling requirements, and utility rates for natural gas and electricity. The results from this study provide a basis for selecting secondary fluids for heat pumping in different locations.

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