Search

Solar heat pump has attracted more and more attention. This paper aims to improve the performance of an absorption solar-ground source heat pump (ASGSHP) through multi-objective optimization. Firstly, a double-effect absorption heat pump module is developed and a simulation model of the ASGSHP is established on TRNSYS platform. Secondly, considering both the economy and the environmental protection, the equivalent uniform annual cost (EUAC) and the environmental impact load (EIL) are taken as two objective functions. The non-dominated sorting genetic algorithm with elite strategy (NSGA-II) is applied to optimize the environmental and economic performance of the ASGSHP by TRNSYS and MATLAB joint. Pareto front of the multi-objective optimization of the ASGSHP system is obtained. Thirdly, using the TOPSIS decision-making method, the best optimization values for three optimization variables including the solar collector area, the storage tank volume and the setting temperature of the auxiliary heater are obtained. The optimization rate of the environmental impact load and the equivalent uniform annual cost of the optimal point selected by the TOPSIS decision-making method is 10.9% and 3.4%, respectively. The research results can provide the basic data and theoretical guidance for the further development and utilization of the solar-ground source heat pump. Multi-objective optimization of an absorption solar-ground heat pump is conducted. The objective functions are related to economic and environmental impacts. Optimization is based on self-built MATLAB with TRNSYS optimization platform. The scatter distribution of design parameters of Pareto front is analyzed. TOPSIS decision-making method is used to select the optimal solution. [ABSTRACT FROM AUTHOR]

This paper takes the independent-developed special parabolic trough collector for the air-conditioning and the double-effect absorption chiller to build a solar cooling system, and simultaneously utilizes the ground heat exchanger(so-called SGAC system) to replace the traditional cooling tower as the heat exhausted side(so-called SAC system) in summer. The simulation model of SGAC is established on TRNSYS. The simulation calculation is performed for the building cooling during the whole cooling season in Beijing. The research results indicate that SGAC has a good stability and high efficiency during the whole cooling season. The performance comparison of SGAC and SAC has been carried out. The economy of SGAC system should also be considered in the determination of the main design and operating parameters. [ABSTRACT FROM AUTHOR]

Byline: Yuehong Bi, Lingen Chen, Fengrui Sun The performance analysis and optimisation of endoreversible simple air heat pump with constant-temperature heat reservoirs is carried out by using finite-time thermodynamics. The expressions of the heating load, the exergetic efficiency and the ecological function of the cycle are derived. The influences of the pressure ratio of the compressor and the allocation of heat exchanger inventory on the optimal performance of the cycle are investigated by detailed numerical examples. Performance comparisons among exergetic efficiency objective, ecological objective and traditional heating load objective are performed. The results may provide guidelines for the design and optimisation of practical air heat pump plants.

SUMMARY In this paper, thermodynamic optimization is applied to analyze the crystallization process of the gas hydrate related to the gas hydrate cool storage system. Thermodynamic optimization model of the gas hydrate crystallization process is established. By taking the entropy generation minimization as the optimization objective, both the optimal control strategy and the optimal cooling rate of the gas hydrate crystallization process are determined. The minimum entropy generation corresponding to the optimal cooling rate decreases by 7.8% compared with normal situation. The results presented in this paper can provide important guidelines for optimal design and operation of the gas hydrate crystallization process. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]