scholarly journals Identification of Existing Challenges and Future Trends for the Utilization of Ammonia-Water Absorption–Compression Heat Pumps at High Temperature Operation

2021 ◽  
Vol 11 (10) ◽  
pp. 4635
Author(s):  
Marcel Ulrich Ahrens ◽  
Maximilian Loth ◽  
Ignat Tolstorebrov ◽  
Armin Hafner ◽  
Stephan Kabelac ◽  
...  
Keyword(s):  
High Temperature ◽  
Water Absorption ◽  
Industrial Sector ◽  
Heat Pumps ◽  
Working Fluid ◽  
Large Temperature ◽  
Future Trends ◽  
Ammonia Water ◽  
Starting Point ◽  
High Temperature Operation

Decarbonization of the industrial sector is one of the most important keys to reducing global warming. Energy demands and associated emissions in the industrial sector are continuously increasing. The utilization of high temperature heat pumps (HTHPs) operating with natural fluids presents an environmentally friendly solution with great potential to increase energy efficiency and reduce emissions in industrial processes. Ammonia-water absorption–compression heat pumps (ACHPs) combine the technologies of an absorption and vapor compression heat pump using a zeotropic mixture of ammonia and water as working fluid. The given characteristics, such as the ability to achieve high sink temperatures with comparably large temperature lifts and high coefficient of performance (COP) make the ACHP interesting for utilization in various industrial high temperature applications. This work reviews the state of technology and identifies existing challenges based on conducted experimental investigations. In this context, 23 references with capacities ranging from 1.4 kW to 4500 kW are evaluated, achieving sink outlet temperatures from 45 °C to 115 °C and COPs from 1.4 to 11.3. Existing challenges are identified for the compressor concerning discharge temperature and lubrication, for the absorber and desorber design for operation and liquid–vapor mixing and distribution and the choice of solution pump. Recent developments and promising solutions are then highlighted and presented in a comprehensive overview. Finally, future trends for further studies are discussed. The purpose of this study is to serve as a starting point for further research by connecting theoretical approaches, possible solutions and experimental results as a resource for further developments of ammonia-water ACHP systems at high temperature operation.

Thermodynamic analysis of triple effect ammonia–water absorption compression (hybrid) cycle

2021 ◽  
pp. 095440892199568
Author(s):  
CP Jawahar
Keyword(s):  
Water Absorption ◽  
Energy Analysis ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Performance Parameters ◽  
Evaporator Temperature ◽  
Ammonia Water ◽  
Absorption Cycle ◽  
Hybrid Cycle

This paper presents the energy analysis of a triple effect absorption compression (hybrid) cycle employing ammonia water as working fluid. The performance parameters such as cooling capacity and coefficient of performance of the hybrid cycle is analyzed by varying the temperature of evaporator from −10 °C to 10 °C, absorber and condenser temperatures in first stage from 25 °C to 45 °C, degassing width in both the stages from 0.02 to 0.12 and is compared with the conventional triple effect absorption cycle. The results of the analysis show that the maximum cooling capacity attained in the hybrid cycle is 472.3 kW, at 10 °C evaporator temperature and first stage degassing width of 0.12. The coefficient of performance of the hybrid cycle is about 30 to 65% more than the coefficient of performance of conventional triple effect cycle.

scholarly journals Calculated and experimental evaluation heat pump distiller on pentane as working substance

2020 ◽  
Vol 324 ◽  
pp. 02007
Author(s):  
Gennady A. Ilyn ◽  
Ilya I. Malafeev ◽  
Vladimir B. Sapojnikov
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Recovery Phase ◽  
High Energy ◽  
Heat Pumps ◽  
Working Fluid ◽  
Vapor Compression ◽  
The Cost ◽  
Reliable Methods ◽  
High Temperature Vapor

One of the most common and reliable methods of water treatment is the method of thermal distillation. Despite the reliability of the method, its application is constrained by high energy intensity. The most effective way to reduce the cost of production of distillate is the use of thermal transformers, providing regenerate and heat recovery phase transformations of the distillate. The use of working fluid with the most favorable thermodynamic properties is of paramount importance for the creation of high efficiency thermotransformers. The work is considered working fluid for high-temperature heat pumps and the results of the calculation-experimental study of high-temperature vapor compression heat-pumping distiller on natural working substance n-pentan.

Development of Corrosion Inhibitors for Absorption Heat Pumps

2002 ◽  
Author(s):  
C. L. Hannon ◽  
J. Gerstmann ◽  
F. B. Mansfeld ◽  
Z. Sun
Keyword(s):  
Water Absorption ◽  
Corrosion Inhibitors ◽  
Earth Metal ◽  
Heat Pumps ◽  
Generation Rate ◽  
Sodium Chromate ◽  
Gas Generation ◽  
Ammonia Water ◽  
Steel Surfaces ◽  
Gas Generation Rate

This paper describes the results of a research project to develop a non-toxic corrosion in hibitor for the protection of carbon steel surfaces of ammonia-water absorption heat pumps through the use of rare earth metal salt (REMS) compounds. Chromate compounds are currently used as corrosion inhibitors in these systems, but are toxic, environmentally harmful, and their use is being phased out. Corrosion concerns in ammonia-water absorption systems are primarily those of non-condensable (NC) gases generated by corrosion reactions impeding the heat and mass transfer processes in the system. The research focused on the development of a dual-protection REMS based strategy of applying a cerium-oxide/hydroxide coating to the metal surface in a process called cerating, in conjunction with a cerium-sulfate solution-based inhibitor. A laboratory test was conducted in test rigs designed to simulate the conditions of temperature and ammonia concentration found in the desorber component of advanced ammonia-water absorption systems. The test compared the NC gas generation rate in a rig with cerated steel surfaces to a rig using sodium chromate as a solution based inhibitor. The cerated test rig demonstrated an NC gas generation rate about 3 times lower than that of the chromate protected rig. Neither rig showed any indications of significant corrosion activity. This work has shown that cerating can provide superior suppression of NC gas generation in ammonia-water absorption systems compared to sodium chromate, in a process that is simple and readily applicable to the commercial manufacture of equipment.

Microchannel component technology for system-wide application in ammonia/water absorption heat pumps

2011 ◽  
Vol 34 (5) ◽  
pp. 1184-1196 ◽  
Author(s):  
Srinivas Garimella ◽  
Matthew D. Determan ◽  
J. Mark Meacham ◽  
Sangsoo Lee ◽  
Timothy C. Ernst
Keyword(s):  
Water Absorption ◽  
Heat Pumps ◽  
Component Technology ◽  
Ammonia Water

Temperature Transformation for High-Temperature Heat Pumps

1988 ◽  
Vol 110 (4) ◽  
pp. 652-657 ◽  
Author(s):  
R. Radermacher ◽  
L. A. Howe
Keyword(s):  
High Temperature ◽  
Heat Pump ◽  
Heat Pumps ◽  
Pure Component ◽  
Effect Of Temperature ◽  
Working Fluid ◽  
Fluid Mixture ◽  
Temperature Transformation ◽  
Temperature Levels ◽  
Very High

A heat pump cycle is introduced that allows heat pumping between two very high temperature levels, while the suction temperature of the working fluid vapor passing through the compressor is considerably lower. This effect of “Temperature Transformation” is achieved by using a working fluid mixture instead of a single pure component and by employing an unconventional cycle design. The proposed cycle allows the extension of heat pump applications to high temperature levels without encountering operating problems for conventional compressors. This cycle and its features are explained. Its performance has been calculated and the results are presented and discussed.

scholarly journals High-temperature heat pump simulator (heatpack) for application in computer laboratory sessions for engineering students

2021 ◽  
Vol 11 (1) ◽  
pp. 16
Author(s):  
Adrián Mota Babiloni ◽  
Carlos Mateu-Royo ◽  
Joaquín Navarro-Esbrí ◽  
Ángel Barragán-Cervera
Keyword(s):  
High Temperature ◽  
Engineering Students ◽  
Waste Heat ◽  
Energy Performance ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Industrial Processes ◽  
Design Parameters ◽  
Working Fluid ◽  
Temperature Heat

A significant amount of energy in the form of heat is lost in industrial processes once it is used in specific processes. Among different technologies, high-temperature heat pumps (HTHP) are a valuable method of recovering low-temperature waste heat in the industry in a very efficient way that can be activated using clean electricity. As a recently investigated technology, they are not yet spread in industrial processes, where traditional technologies are preferred. Therefore, this work shows an HTHP computer program (named HeatPack) to be used as a simulator by the university or technical students of courses included in the area of applied thermodynamics engineering. This interactive and user-friendly platform allows the modification of different operating and design parameters and the working fluid. As outputs, the program provides the rest of the operating parameters and the energy performance of the cycle (quantified by the coefficient of performance, COP). A comparison between the proposed HTHP and a gas boiler is also performed by the program and the energetic, environmental, and economic savings are displayed. Students, as the main target of users of the program, can observe how this technology can provide very relevant emission reductions in comparison with fossil fuel-based boilers, under which situation the energy performance of the HTHP is higher, and which alternative low global warming potential (GWP) refrigerants can provide more advantages. In addition to the educational use, this software can be used to design and study the integration of HTHPs in existing industrial needs to evaluate the feasibility.

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