An Optimizing Method for Preparing Natural Refrigerant: Ammonia-water Nanofluids

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.

Download Full-text

Effects of sub-cooler on cooling performance of air conditioning system with natural refrigerant R290

10.1063/5.0030376 ◽

2020 ◽

Author(s):

Gavin Cakraditya ◽

Fathurrahman Yudhi ◽

Ardiyansyah Yatim

Keyword(s):

Air Conditioning ◽

Air Conditioning System ◽

Cooling Performance ◽

Natural Refrigerant

Download Full-text

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

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408921995682 ◽

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.

Download Full-text

Analyzing Properties of Air as a natural refrigerant using MCDM methodology

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1059/1/012040 ◽

2021 ◽

Vol 1059 (1) ◽

pp. 012040

Author(s):

Mohammed Hameeduddin Haqqani ◽

Mohammed Azizuddin ◽

Syed Shuibul Qarnain ◽

S. Bathrinath

Keyword(s):

Natural Refrigerant

Download Full-text

A Study on the Performance of Drinking Fountain Using CO2 Heat Pump under Different System Pressures

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.2433 ◽

2010 ◽

Vol 44-47 ◽

pp. 2433-2437 ◽

Cited By ~ 1

Author(s):

Yu Lieh Wu ◽

Yu Dai Shiue ◽

Kuo Hsiang Chien ◽

Chiu Li Wang

Keyword(s):

Carbon Dioxide ◽

Heat Source ◽

Heat Pump ◽

Air Conditioning ◽

High Performance ◽

High Efficiency ◽

Electric Heating ◽

Alternative Refrigerant ◽

Saving Effect ◽

Natural Refrigerant

To avoid continuous damage of ozone layer and deterioration of global warming, many countries have devoted to the development and application of natural refrigerant. Although CO2, an alternative refrigerant in the area of air conditioning is not the best all-temperature refrigerant, it has the lowest operating risk as compared to hydrocarbon (HCs) and ammonia.Traditional drinking fountain provides heat source through secondary energy source - electric heating; however, the heating effect is limited. Since heat pump has a high performance, this study used a carbon dioxide heat pump, which has energy-saving effect and high efficiency, to provide heat source to drinking fountains. It further assembled the drinking fountain system with carbon dioxide heat pump and analyzed its performance.

Download Full-text