Solar refrigeration is an important area for solar technology applications, which can alleviate energy shortages and environmental problems, and is a highly promising area with simple structures and low operating costs, as well as a hot spot for research on refrigeration technology today。
Solar lithium brominated absorbers in the current variety of solar refrigeration methodsRefrigeratorsRefrigeration is more efficient and can operate at lower heat source temperatures and is one of the most successful ways to apply solar refrigeration at present。
Solar brominated lithium absorbent refrigeration systems consist of solar collectors, generators, condensers, condensers, evaporation valves, solute thermal exchangers, absorbers and pumps. The cycling process is a thermal exchange process in which refrigerant vapours are evaporated in the generator, the brominated lithium solution is diluted, the brominated lithium solution is absorbed in the absorbent, the brominated lithium solution is diluted by enrichment, and the refrigerant water in the evaporation unit is injected for cooling purposes at low pressure。
Currently, solar brominated lithium absorbent chillers are mainly single-activated, double-activate, triple-effect equivalent combined-refrigeration cycles, and the most widely used in the market are dual-effect units。
1. Solar-driven mono-brominated lithium absorbers
The single-activated lithium absorbent chiller is the simplest type of structure in the absorbent chiller, with the best working temperature ranging from 80 to 100°c, and its maximum cop (performance factor, equal to the ratio of cooling/heat to cooling/thermal system input power provided by refrigeration equipment) can reach 0. 7 at the heat source temperature of 85°c. Because the solution is subject to crystallization conditions, the heat source temperature of the chiller cannot exceed 150°c. The generation of the same amount of cooling and single-activated lithium absorbent chillers consume much more energy than conventional compressor chillers, but their advantage is that low-grade energy can be fully utilized as a driver, while low-temperature solar collectors generate hot water that can be used to drive single-effect absorbent chillers, thus saving electricity and energy, which cannot be compared with compressed chillers。
2 solar double-effect, tri-bo, lithium bicide refrigerator
The heat source temperature of single absorbent chillers is limited by concentrated solution crystallization, and in order to take full advantage of high-temperature heat sources, dual- and triple-effect absorbent chillers are available. Two-effect absorbent chillers have an additional high pressure generator, a high-temperature fluid thermal exchanger, and a condenser for heat。
It works as follows: in high pressure generators, the thin solution is heated with high pressure vapour, producing refrigerant vapour at higher pressure. Rare solution concentrates into intermediate solution. This portion of the vapour is then introduced into the low pressure generator as thermal source, and the heating high pressure generator flows through the high temperature soluble thermal exchanger to the intermediate solution in the low pressure generator, so that the refrigerant vapour is re-generated under condensed pressure and the intermediate solution is condensed into a concentrated solution. The energy of high-pressure vapour is used twice in the high-pressure generator and the low-pressure generator, and is therefore called a double cycle。
According to the above, expansion is a three-effect cycle. With the use of high-temperature heat sources, double-absorption chillers can have cop values of 1. 0 to 1. 2 and triple-effect values of 1. 7, which represents a significant increase over the single-effect cop values。
With the development of science and technology and the emergence of green buildings, solar refrigeration air-conditioning technologies will be improved and improved, and costs will be reduced significantly, and it is believed that solar brominated lithium absorbent refrigeration air-conditioning will have greater prospects for development。
Cope central chinese kitchen
Xinhua network science and technology department
Cope china-scientific principles
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