Research On Performance Of Solar Air - Conditioning System Driven By CPC Collector

Currently, the research on solar air conditioning is conducted by many scholars, especially the lithium bromide refrigeration unit mode driven by solar energy is paid more attention in the field of solar thermal utilization. Due to its relatively high utilization of thermal energy, the solar-powered lithium bromide refrigeration units is researched by domestic researchers. However, the research of matching aspects between collector and lithium is focus on theoretical calculation and analysis, which lacks the real experimental data to validate. The design and theoretical on the single effect lithium bromide air-conditioning system which driven by CPC collectors is described in this article, and a reasonable mix model for collector-driven lithium bromide units is given. The heating transfer process of CPC with a U-shaped tube is analyzed, the refrigeration and heating process of the single effect of lithium bromide unit driven by CPC is tested and analyzed, which provide relevant theoretical and practical basis for the combination system of solar collectors and air-conditioning. The main researches are as follow:(1) CPC heat transfer modeling and theoretical analysis, including the analysis and the establishment of the theory of U-shaped tubes. According to the theory of the CPC collector to design CPC collectors and to test it, obtaining an average efficiency of about 0.3. The test of CPC efficiency and room dimensions determined the collector area 93.5m2, refrigeration units 11 kW, holding tanks 2.0T, auxiliary heat source 24 kW, cooling towers 5m3 / h and 2 fan coils of 6.3kW.(2) The lithium bromide absorption refrigeration air conditioning system driven by CPC was built, then given a series of test results and analyses, and the result showed that the average heat loss of tank was 467 W, and 5.5kW with CPC collectors system. The collector power ranged from 17 to 58 kW. And winter heating power ranged from 3.8 to 4.3kW, summer average cooling power was 13.8kW. The tests showed that the system can fully meet the requirements for the indoor comfortable conditions.(3) The optimization analysis for the problems which found during the test study was proposed, including CPC collectors, control systems, pipe insulation, auxiliary heat source and matching the system. The theoretical analysis showed that the structure of the CPC concentration ratio can be increased from 1.3 to 1.5 in order to reduce its costs. The feedback regulation control system was built instead of a simple temperature control for the irradiance. Meanwhile, an auxiliary gas source system was used as a heat source for long-running unit. Moreover, the pipe insulation thickness of 0.08 m can be recommended to reduce the heat losses.