The Performance Simulation Of Single-Double Effect LIBR Absorption Refrigeration System With Multi-Heat Source

More and more researches on new energy have been carried out due to the excessive consumption of conventional energy sources, the increasingly serious problem of energy shortage and the enhancement of people’s environmental awareness. The advantages of solar energy such as clean, green and large storage have obtained much attention. But because of its instability, it could not meet the people’s needs. It is necessary to introduce other forms of energy for supplement. A single-double effect LiBr absorption refrigeration system with multi-source has been presented in this paper, which could switch among various operating modes depending on the variations in the intensity of solar radiation and the cooling capacity that the user needs. The running program has many advantages, such as the diversity of operating mode, better adaptability, low operating efficiency, high equipment utilization and so on.Theoretical analysis on components and the multi-heat source single-double effect LiBr absorption refrigeration system were presented in this paper. Based on the first and second laws of thermodynamics, calculation of energy balances and exergy balances were did on them. Exergic efficiency of the system and local exergy loss coefficient of the important components were calculated.Rational efficiency was used to evaluate the improvement of the exergy utilization potential in the system. Local exergy loss coefficient was displayed exergy loss distribution in the system. The part of exergy loss in the system has been analyzed, and some measures to improve system exergy efficiency were put forward. The simulation model of multi-heat source single-double effect LiBr absorption refrigeration system was established by TRNSYS, and the simulation was made on different operation modes respectively. By changing the parameters of PTC collector area, cooling water inlet temperature, refrigerant water outlet temperature and the proportion of single and double running time, we examine their impact on system performance. The increase of temperature at both cooling water outlet and the chilled water inlet could cause the exergy efficiency lowering for the system. When the solar double-effect absorption chilling system operated alone, the largest exergy loss for the system would be the solar collector, so it was crucial to improve the solar collectors for system optimization. When the single-effect chilling system was running combined with the double-effect one, the double-effect chilling model would be started at 11 am, which made the whole system in an optimum working status. When the single-effect absorption chilling system droved by electric energy operated alone, the largest exergy loss for the system would be heat storage tank, so the improvement of the heat storage tank could improve the performance of system effectively. In this paper, the exergy analysis method has been used to study the energy transfer law in the system, and it has theoretical significance on the evaluation and improvement of the actual system.