Design of a Vapour Compression Heat Pump in a Heat Exchanger Network

Author(s):  
V. R. Pendyala ◽  
V. S. Patwardhan
2020 ◽  
Vol 15 (2) ◽  
pp. 299-307
Author(s):  
Gilbong Lee ◽  
Chul Woo Roh ◽  
Bong Soo Choi ◽  
Eunseok Wang ◽  
Ho-Sang Ra ◽  
...  

Abstract Reports by the US Department of Energy in 2014 evaluated membrane heat pump technology as one of the most promising alternatives to conventional vapour compression methods. Vapour compression methods maintain an evaporator temperature lower than the dew point to deal with the latent heat load. In membrane heat pump systems, only the water vapour is transferred and there is no phase change. The migration is caused by the difference in vapour pressure before and after the membrane. A vacuum pump or blower is used to create the pressure difference. However, there is no methodology for predicting dehumidification performance of membranes when used as part of a cooling system. In this study, using the assumption that there is a similarity between heat transfer and moisture pervaporation, the performance indices of the membrane are derived using a well-known heat exchanger method, the ε-NTU models. Performance estimations are calculated for two representative system layouts: bypass and vacuum. Simple relations between design parameters are suggested, giving design guidelines for researchers.


2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Valli Trisha ◽  
Kai Seng Koh ◽  
Lik Yin Ng ◽  
Vui Soon Chok

Limited research of heat integration has been conducted in the oleochemical field. This paper attempts to evaluate the performance of an existing heat exchanger network (HEN) of an oleochemical plant at 600 tonnes per day (TPD) in Malaysia, in which the emphases are placed on the annual saving and reduction in energy consumption. Using commercial HEN numerical software, ASPEN Energy Analyzer v10.0, it was found that the performance of the current HEN in place is excellent, saving over 80% in annual costs and reducing energy consumption by 1,882,711 gigajoule per year (GJ/year). Further analysis of the performance of the HEN was performed to identify the potential optimisation of untapped heating/cooling process streams. Two cases, which are the most cost-effective and energy efficient, were proposed with positive results. However, the second case performed better than the first case, at a lower payback time (0.83 year) and higher annual savings (0.20 million USD/year) with the addition of one heat exchanger at a capital cost of USD 134,620. The first case had a higher payback time (4.64 years), a lower annual saving (0.05 million USD/year) and three additional heaters at a capital cost of USD 193,480. This research has provided a new insight into the oleochemical industry in which retrofitting the HEN can further reduce energy consumption, which in return will reduce the overall production cost of oleochemical commodities. This is particularly crucial in making the product more competitive in its pricing in the global market.


2020 ◽  
Vol 53 (2) ◽  
pp. 11780-11785
Author(s):  
María P. Marcos ◽  
José Luis Pitarch ◽  
César de Prada

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1893
Author(s):  
Kwonye Kim ◽  
Jaemin Kim ◽  
Yujin Nam ◽  
Euyjoon Lee ◽  
Eunchul Kang ◽  
...  

A ground source heat pump system is a high-performance technology used for maintaining a stable underground temperature all year-round. However, the high costs for installation, such as for boring and drilling, is a drawback that prevents the system to be rapidly introduced into the market. This study proposes a modular ground heat exchanger (GHX) that can compensate for the disadvantages (such as high-boring/drilling costs) of the conventional vertical GHX. Through a real-scale experiment, a modular GHX was manufactured and buried at a depth of 4 m below ground level; the heat exchange rate and the change in underground temperatures during the GHX operation were tracked and calculated. The average heat exchanges rate was 78.98 W/m and 88.83 W/m during heating and cooling periods, respectively; the underground temperature decreased by 1.2 °C during heat extraction and increased by 4.4 °C during heat emission, with the heat pump (HP) working. The study showed that the modular GHX is a cost-effective alternative to the vertical GHX; further research is needed for application to actual small buildings.


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