Thermodynamic Analysis of Solar Heat Exchanger Assisted Ammonia-Water VARS System

Abstract

This research focused on the importance of the Ammonia Water Vapour Absorption Refrigeration (VARS) system using solar heat exchangers. The thermal energy needed to operate the VARS through electrical energy can be saved by means of a solar heat exchanger during the daytime. In this case, the strong solution of NH3-H2O passed through a copper/aluminium pipe of the solar flat-plate collector. The top ceiling flat-plate collector is covered with transparent glass through which the solar radiation heats the pipe and the strong solution of NH3-H2O within it passes. Due to heating the NH3 vaporizes and separates out from the strong solution in the flash chamber. Then the vapour NH3 flows into the condenser due to the buoyancy effect. It is interesting to discern the significance of solar-assisted heat exchangers to operate VARS and save electrical energy during the daytime. However, the daytime temperate variation is due to solar radiation in the heat supplied to any solar heat exchanger. The performance of the heat exchanger is governed by the mass flow rate binary solution. The effectiveness significantly affects the COP of VARS. Moreover, the VARS operating cost is reduced.

Keywords

• solar heat exchanger
• vapor absorption
• dittus boelter equation