Rational assessment and selection of air source heat pump system operating with CO2 and R407C for electric bus

2022 ◽  
Vol 182 ◽  
pp. 86-101
Author(s):  
Haidan Wang ◽  
Yulong Song ◽  
Yiyou Qiao ◽  
Shengbo Li ◽  
Feng Cao
PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256836
Author(s):  
Bo Yu ◽  
Yuye Luo ◽  
Wenxiao Chu

The study is aimed at the frosting problem of the air source heat pump in the low temperature and high humidity environment, which reduces the service life of the system. First, the frosting characteristics at the evaporator side of the air source heat pump system are analyzed. Then, a new defrost technology is proposed, and dimensional theory and neural network are combined to predict the transfer performance of the new system. Finally, an adaptive network control algorithm is proposed to predict the frosting amount. This algorithm optimizes the traditional neural network algorithm control process, and it is more flexible, objective, and reliable in the selection of the hidden layer, the acquisition of the optimal function, and the selection of the corresponding learning rate. Through model performance, regression analysis, and heat transfer characteristics simulation, the effectiveness of this method is further confirmed. It is found that, the new air source heat pump defrost system can provide auxiliary heat, effectively regulating the temperature and humidity. The mean square error is 0.019827, and the heat pump can operate efficiently under frosting conditions. The defrost system is easy to operate, and facilitates manufactures designing for different regions under different conditions. This research provides reference for energy conservation, emission reduction, and sustainable economic development.


Author(s):  
Zhang Guihong ◽  
Yang Yi ◽  
Chen Jianbo ◽  
Mei Tianxiang ◽  
Gu Haiqin ◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Jie Jia ◽  
Xuan Zhou ◽  
Wei Feng ◽  
Yuanda Cheng ◽  
Qi Tian ◽  
...  

The simultaneous need for energy efficiency and indoor comfort may not be met by existing air source heat pump (ASHP) technology. The novelty of this study lies in the use of a new gravity-driven radiator as the indoor heating terminal of ASHPs, aiming to provide an acceptable indoor comfort with improved energy efficiency. To confirm and quantify the performance improvement due to the proposed system retrofit, a field test was conducted to examine the system performance under real conditions. In the tests, measurements were made on the refrigerant- and air-side of the system to characterize its operational characteristics. Results showed that the proposed radiator has a rapid thermal response, which ensures a fast heat output from the system. The proposed system can create a stable and uniform indoor environment with a measured air diffusion performance index of 80%. The energy efficiency of the proposed system was also assessed based on the test data. It was found that the system’s first law efficiency is 42.5% higher than the hydraulic-based ASHP system. In terms of the second law efficiency, the compressor contributes the most to the overall system exergy loss. The exergy efficiency of the proposed system increases with the outdoor temperature and varies between 35.02 and 38.93% in the test period. The research results and the analysis methodology reported in this study will be useful for promoting the technology in search of energy efficiency improvement in residential and commercial buildings.


2013 ◽  
Vol 13 (9) ◽  
pp. 1406-1414
Author(s):  
Wang He ◽  
Liu Yong-Shun ◽  
Liu Xiao-Li ◽  
Duan Jin-Hui ◽  
Xue Song ◽  
...  

Author(s):  
Z Yuhan ◽  
W Jinshun ◽  
L Mu ◽  
Z Xingxing ◽  
Z Lining ◽  
...  

2011 ◽  
Vol 46 (10) ◽  
pp. 2052-2059 ◽  
Author(s):  
Li Yongcun ◽  
Chen Guangming ◽  
Tang Liming ◽  
Liu Lihua

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