㶲分析 , COP分析

1. Journal of Shanghai Jiao Tong University (Science): 基于实验数据的直膨式太阳能热泵㶲分析

原文链接 https://doi.org/10.1007/s12204-020-2228-6

The purpose of this research is to reveal the exergy variation of each component in a direct-expansion solar-assisted heat pump (DX-SAHP) system. Exergy analysis of the DX-SAHP system with R134a is conducted,and the performance evaluation is done. The proposed system is mainly composed of a bare plate solar collector/evaporator, a hermetic variable-frequency rotary-type compressor, a micro-channel condenser and an electronic expansion valve. The experimental data include the exergy loss rates, irreversibility rates and exergy loss ratios of all components and the influences of ambient temperature on these parameters. The analysis results show that the average irreversibility rate of the compressor is 204.8 W at an ambient temperature of 16 °C, and 149.9 W at an ambient temperature of 27 °C. The highest irreversibility rate occurs in the compression process, followed by the throttling process, the evaporation process and the condensation process.

论文标题为 Exergy Analysis of Direct-Expansion Solar-Assisted Heat Pump Based on Experimental Data

制冷循环性能系数ε_R

2. Journal of Shanghai Jiao Tong University (Science): 采用不同工质对的两级吸收式制冷系统性能研究

原文链接 https://doi.org/10.1007/s12204-020-2209-9

The objective of this paper is to present a simulation study on the two-stage absorption refrigeration systems of 2.5 kW capacity using LiBr-H₂O, NH₃-H₂O and R124-DMAC as working pairs. Under the design condition that the generating, absorbing, evaporating and condensing temperatures are 75 °C, 45 °C, 5 °C and 40 °C, respectively, the high and low pressure side solution circulation ratios and the coefficient of performance (COP) for the systems are calculated. Then the influences of medium, generating, absorbing, evaporating and condensing temperatures on system performances are analyzed. The results show that under the design condition, the COP of the LiBr-H₂O system can reach 0.49, superior to those of the NH₃-H₂O and R124-DMAC systems, which are 0.32 and 0.31, respectively. Furthermore, the medium temperature for higher COP lies in an interval of 64—67 °C for the LiBr-H₂O, NH3-H₂O and R124-DMAC systems. High generating temperature and low absorbing temperature can decrease the high and low pressure side solution circulation ratios, and can also increase the COP. High evaporating temperature can decrease the low pressure side solution circulation ratio and increase the COP. Low condensing temperature can decrease the high pressure side solution circulation ratio and increase the COP.

论文标题为 Comparative Study on Two-Stage Absorption Refrigeration Systems with Different Working Pairs

热机性能系数ε_hp

3.Journal of Shanghai Jiao Tong University (Science):  基于 LSTM网络的通风系统热需求预测

原文链接 https://doi.org/10.1007/s12204-021-2277-5 

Load forecasting can increase the efficiency of modern energy systems with built-in measuring systems by providing a more accurate peak power shaving performance and thus more reliable control. An analysis of an integrated CO₂ heat pump and chiller system with a hot water storage system is presented in this paper. Drastic power fluctuations, which can be reduced with load forecasting, are found in historical operation records. A model that aims to forecast the ventilation system heating demand is thus established on the basis of a long short-term memory (LSTM) network. The model can successfully forecast the one-hour-ahead power using records of the past 48 h of the system operation data and the ambient temperature. The mean absolute percentage error (MAPE) of the forecast results of the LSTM-based model is 10.70%, which is respectively 2.2% and 7.25% better than the MAPEs of the forecast results of the support vector regression based and persistence method based models.

论文标题为 Ventilation System Heating Demand Forecasting Based on Long Short-Term Memory Network

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https://link.springer.com/journal/12204/volumes-and-issues/26-2