Theoretical analysis of energy-saving performance and economics of CO2 and NH3 heat pumps with simultaneous cooling and heating applications in food processing

2016 ◽  
Vol 65 ◽  
pp. 129-141 ◽  
Author(s):  
Yefeng Liu ◽  
Eckhard A. Groll ◽  
Kazuaki Yazawa ◽  
Orkan Kurtulus
2013 ◽  
Vol 7 (4) ◽  
pp. 28-33
Author(s):  
Monika Pawlita

Background: The methods of heating houses with system components determine the energy-saving systems. Energy-saving solutions allow to maintain comfortable conditions in the house, while minimizing the cost associated with its operation and at the same time helping to protect natural environment. The examples of such solutions include condensing boilers, heat pumps and solar collectors.Material and methods: The object of the analysis in this paper is typical single-family house occupying the area of 150 m². The comparison of analyzed heating system for a single-family house, including modern energy sources, allows the assessment of the most cost-effective method of heating. Results: Choosing rational method of heating for a single-family house is dictated mainly by economic reasons. The efficiency of the heating sources is also very important. In addition, an important factor is a heating period, which depends on the weather conditions in a given year.Conclusions: The costs of fuel/energy are still growing. Fuel selection is determined mainly by fuel calorific value and the price. To select the type of the heating source one must take into account the cost of kWh of heat.


Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4313 ◽  
Author(s):  
Boahen ◽  
Choi

The use of cascade heat pumps for hot water generation has gained much attention in recent times. The big question that has attracted much research interest is how to enhance the performance and energy saving potential of these cascade heat pumps. This study therefore proposed a new cycle to enhance performance of the cascade heat pump by adopting an auxiliary heat exchanger (AHX) in desuperheater, heater and parallel positions at the low stage (LS) side. The new cascade cycle with AHX in desuperheater position was found to have better performance than that with AHX at heater and parallel positions. Compared to the conventional cycle, heating capacity and coefficient of performance (COP) of the new cascade cycle with AHX in desuperheater position increased up to 7.4% and 14.9% respectively.


2011 ◽  
Vol 383-390 ◽  
pp. 1933-1937
Author(s):  
Wei Xiu Shi ◽  
Wei Yi Li ◽  
Li Sheng Pan ◽  
Zhi Hua Zhou

Under the situation of energy crisis, air source heat pumps are paid more attention recently. In terms of energy saving, the feasibility and performance of boiled water machine with air source heat pump are studied by experiment in this paper. The results are as follows: the best outlet temperature of heat pump is 55°C in winter, and that is 65°C in other seasons correspondingly. Electromagnetic heater is used as the accessorial heating method, which can heat water to 95°C so as to be fit to drinking. Moreover, the energy saving effect of the unit is remarkable. At the end of the paper, the preliminary conception of structure and automatic control is proposed.


2011 ◽  
Vol 347-353 ◽  
pp. 587-590
Author(s):  
Qing Hai Luo ◽  
Zheng Zuo

This paper analyzes the energy consumption of hot water supply in buildings and the insurmountable shortcoming of low energy efficiency of conventional water heaters, and investigates the progress and problems of developing heat pump water heaters. It is pointed out that developing of heat pump water heaters is one of the efficient approaches to improve the energy efficiency of hot water supply.


2014 ◽  
Vol 73 (1) ◽  
pp. 1022-1031 ◽  
Author(s):  
Andrea Frazzica ◽  
Gerrit Füldner ◽  
Alessio Sapienza ◽  
Angelo Freni ◽  
Lena Schnabel

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