Zhihao Zheng¹, Yanbo Che^1,*, Hailian Bi¹, Dan Wu¹, Wei He²

Energy Engineering, Vol.119, No.2, pp. 637-651, 2022, DOI:10.32604/ee.2022.016661

Abstract With the implementation of electric energy alternatives, the large-scale application of electric energy substitution represented by air-source heat pumps has replaced traditional coal-fired heating, which is beneficial for the environment and alleviates air pollution. However, the large-scale application of air-source heat pumps has brought power quality problems such as voltage sags, harmonic pollution, and three-phase imbalance to the distribution network. This paper studies the fixed-frequency and variable-frequency air-source heat pump, introduces its working principle, analyzes the mechanism of its power quality problem. Moreover, the paper establishes a simulation model for the fixed-frequency heat pump and variable-frequency heat pump to connect… More >

Xueqin Tian¹, Jinfei Sun², Tong Xu¹, Mengran Cui², Xinlei Wang¹, Jianxiang Guo², De-gejirifu^1,*, Na Wang¹

Energy Engineering, Vol.119, No.2, pp. 723-737, 2022, DOI:10.32604/ee.2022.015982

Abstract Although the Combined Cooing, Heating and Power System (hereinafter referred to as “CCHP”) improves the capacity utilization rate and energy utilization efficiency, single use of CCHP system cannot realize dynamic matching between supply and demand loads due to the unbalance features of the user’s cooling and heating loads. On the basis of user convenience and wide applicability of clean air energy, this paper tries to put forward a coupled CCHP system with combustion gas turbine and ASHP ordered power by heat, analyze trends of such parameters as gas consumption and power consumption of heat pump in line with adjustment of… More >

Yanxue Li^1,*, Weijun Gao^1,2, Xiaoyi Zhang², Wenya Xu¹, Yingjun Ruan³, Yinzhong Wang⁴

Energy Engineering, Vol.119, No.1, pp. 63-81, 2022, DOI:10.32604/EE.2022.016209

Abstract The building sector contributes a large ratio of final energy consumption, and improving building energy efficiency is expected to play a significant role in mitigating its carbon dioxide emission. Herein, we collected the on-site measurement data to investigate the techno-economic performances of different heat pump types that exist in building space heating projects in Qingdao, China. An in-depth analysis revealed the temperature variations of measured low-grade heat sources over the whole heating supply period, and urban sewage water shows high stable heat energy quality compared with seawater and geothermal heat resources. Operational behaviors including cycling inlet and outlet temperature of… More >

Chunxue Gao^1,*, Yu Hao¹, Qiuxin Liu^1,2

Energy Engineering, Vol.118, No.3, pp. 667-678, 2021, DOI:10.32604/EE.2021.014703

Abstract Based on the characteristics of sewage from beauty salons, a simulation model of a small sewage source heat pump triple supply system that can be applied to such places is established to optimize the operating conditions of the system. The results show that with the increase of sewage temperature and flow, the performance of the system also increases. In summer conditions, the system provides cooling, recovers waste heat and condensed heat from sewage, with a COP value of 8.97; in winter conditions, the system heats and produces hot water, with a COP value of 2.44; in transitional seasons, only hot… More >

Taihong Liu¹, Dingchen Wu^2,*, Fei Xu³, Panpan Song², Mingshan Wei², Jian Wu¹, Xiaochun Bai¹

Energy Engineering, Vol.118, No.3, pp. 535-548, 2021, DOI:10.32604/EE.2021.014326

Abstract In view of the Three North areas existing wind power absorption and environment pollution problems, the previous scholars have improved the wind abandon problem by adding electrothermal coupling equipment or optimizing power grid operation. In this paper, an electrothermal integrated energy system including heat pump and thermal storage units was proposed. The scheduling model was based on the load data and the output characteristics of power units, each power unit capacity was programmed without constraints, and the proposed scheduling model was compared with the traditional combined heat and power scheduling model. Results showed that the investment and pollutant discharge of… More >

Faizan Ahmed^*, Waqar Ahmed Khan, Jamal Nayfeh

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 2843-2856, 2021, DOI:10.32604/cmc.2021.012041

Abstract In the present study, an attempt is made to enhance the performance of heat pump by utilizing two types of nanofluids namely, copper and alumina nanofluids. These nanofluids were employed around the evaporator coil of the heat pump. The nanofluids were used to enhance the heat input to the system by means of providing an external jacket around the evaporator coil. Both the nanofluids were prepared in three volume fractions 1%, 2% and 5%. Water was chosen as the base fluid. The performance of the heat pump was assessed by calculating the coefficient of performance of the system when it… More >