Feasibility of air cycle systems for low-temperature refrigeration applications with heat recovery

Author(s):  
N J Williamson ◽  
P K Bansal

In this paper the viability of an air cycle refrigeration system (Joule cycle) is investigated for a moderately low-temperature cooling system with heat recovery. The goal is to determine the best possible cycle configuration of heat exchangers and turbomachinery components for this particular application, and then to determine whether it can compete with a conventional vapour compression system. Simple models were developed for each cycle configuration, and the results were compared with each other on a consistent basis. The sensitivity of the system to heat exchanger effectiveness and expander and compressor efficiency was determined, and contours were plotted.

2019 ◽  
Vol 8 (2) ◽  
pp. 2387-2390

Conservation of energy is the important factor from global point of view. Waste heat recovery has become significantly necessary and instant effort should be made to conserve this waste energy. Presently the refrigerator system rejects a lot of heat through condenser. This heat can be used for a variety of useful purposes. A multiuse refrigeration setup has been developed in which, both heating and cooling will be done simultaneously with the help of single vapour compression refrigeration cycle. It has a waste heat recovery system from the compressor for heating effect. Here without disturbing refrigeration cycle, the waste heat energy is used for useful work. The study has shown that such a system is technically feasible and economically viable. This concept has a scope of applications in variety of products such as air conditioners, freezers, water coolers and small scale refrigeration plants. This project leads to hybrid heating and cooling application with same vapour compression refrigeration system


2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Sivakumar M ◽  
Mahalingam S ◽  
Ranjithkumar V

In today’s world refrigeration systems play a vital role to fulfil the human needs. A continuous research is being carried out by many researchers in order to improve the performance of these systems. Presently used, vapour compression refrigeration system does not work efficiently due to shortage of electric power. This study covers a broad overview of solar photovoltaic technology, which uses easily available solar energy for refrigeration purpose. It includes a motor, a compressor, an inverter and battery, a photovoltaic controller and panels. This can be done by converting solar energy in to electricity by means of photovoltaic devices, which can be utilized by the electric motor to drive vapour compression refrigeration system. The main objective of the study is managing the shortage of electric power, in living environments by using a cooling system coupled to a solar installation. In this solar refrigeration system, when conventional refrigerants like (R22, HFCR134a, R600, etc.) are used it leads to low thermal conductivity, heat transfer rate and COP level and some of the other impacts are acid rain, melting of glaciers, sea level raising, health impacts, atmospheric pollution, ozone depletion, which is very hazardous to the environment. To avoid these threats, one of the ways is to use nanofluids which are not harmful to the environment. The usage of nanofluids results in high thermal conductivity, heat transfer rate and give better COP level. The following three nanofluids Al2o3, Zro2, Cu2o have been already used in the refrigeration system. Some of the properties of given nanofluids will be changed to innovate new nanofluids. The innovated nanofluids will be used in refrigeration system and the same will be compared with other nanofluids like R22, R134a, R290, and R600a. Even though Al2o3, Zro2, Cu2o gives good results, the new nanofluids have been innovated for better results.


Energy ◽  
2016 ◽  
Vol 97 ◽  
pp. 460-469 ◽  
Author(s):  
Adriano Desideri ◽  
Sergei Gusev ◽  
Martijn van den Broek ◽  
Vincent Lemort ◽  
Sylvain Quoilin

Vestnik MEI ◽  
2021 ◽  
pp. 51-57
Author(s):  
Dakkah Baydaa Bo ◽  
◽  
I′ldar A. Sultanguzin ◽  
Yuriy V. Yavorovsky ◽  
◽  
...  

Heat losses in industrial processes can be divided into three sections (high-, medium-, and low-temperature heat), depending on the temperature of the exhaust gases. This heat is usually recovered either by heat exchangers or by a closed Rankine cycle. However, about 60% of low-temperature heat losses remain irreplaceable. Currently, the organic Rankine cycle has become a promising method of low-temperature energy recovery, and several theoretical studies on this topic have appeared, but a small number of experimental studies have been performed. In our work, we have built a 2 kW heat recovery laboratory test bench using tube-type heat exchangers, a gear pump and a turbo expander on the working fluid R141b. As a result, we found that the efficiency of the cycle increases as the boiling point and pressure increase, but an increase in overheating at the inlet of the expander leads to a decrease in efficiency due to the use of the working fluid R141b. At the inlet of the evaporator and the outlet of the condenser, respectively, overheating and supercooling of the working fluid occurs, which negatively affects the efficiency of the cycle. The amount of useful heat obtained was 45.4 W with an efficiency of 2.24%. as a result of low efficiency of the expander and pump, as well as leaks during the test. The development of an experimental test bench with working on organic Rankin cycle requires long-term research work and great scientific potential. In the future, it will be necessary to create a new test bench based on a deeper study, so that we can get a higher efficiency of the expander and pump, which would affect the efficiency of this cycle. Also, we need to replace the working fluid in the cycle with a more efficient one.


2011 ◽  
Vol 71-78 ◽  
pp. 292-295
Author(s):  
Lin Wang ◽  
Xiao Long Cui ◽  
Ying Ying Tan ◽  
Yu Wang

Based on conservation of mass, total mass balance equation and component mass balance equation, mathematical models of thermodynamic for the auto cascade refrigeration cycle are established. Thermophysical properties in solving the governing equation are called from the NIST REFPROP7.0. Thermodynamic properties of the auto cascade refrigeration cycle using binary mixtures, namely, R170/R290, R23/R227ea, R116/R134a, R23/R134a, R170/R600a, R170/R600 and R170/R152a as refrigerants is evaluated. R170/R600a is selected for the low temperature refrigeration system, and the influences of cycle mole fraction, compression ratio and evaporating pressure on the cycle performance are analysed.


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