These ARSs use a combination of water as the refrigerant and lithium bromide as the absorbent), as a working fluid. These systems are also called absorption chillers and have a wide range of applications in refrigeration and air conditioning or pre-cooling operations and are produced in sizes ranging from 10 to 1000 tons, leading to low evaporation temperature of the 4BC (with a minimum pressure of 0.8 kPa), because water is used as a refrigerant. In practical applications the temperature 5VC. Low-pressure steam is the main energy source for these H2O-LiBr absorption systems. Despite their Cops less than unity, cheap energy can make these systems economically compete with a much higher COP values for vaporcompression systems. In practical H2O-LiBr ARSs evaporator and absorber are combined in the shell of the low-pressure side and generator, condenser and merged into another shell increased pressure. Liquid-to-liquid heat exchanger is organized in order to increase the efficiency of the system and, hence, improve the COP.
It is the same principle as other ARSs. In the H2O-LiBr ARS, crystallization (solidification of LiBr) appears to be a serious problem. Crystallization lines are shown on the pressure, temperature and enthalpy-concentration charts. Dipping in the field of crystallization causes the formation in the slush, and as a result of blockage of the flow inside the pipes and system outage. To avoid this problem, practical systems are designed with control devices to maintain the condensing pressure is artificially inflated. Please note that the absorption chillers are divided into two categories as follows:
Single-stage (one effect) ARS: Units using low-pressure (135 kPa or less) as the driving force. These units usually have a COP of 0.7. Dual-stage, dual effect) ARS: the devices are available as gas (direct gas as a fuel, or the hot exhaust gases from the gas turbine or engine or steam-driven with high pressure steam (270 950 kPa). These units usually have a COP of 1.0 to 1.2. To achieve this improved performance they have a second generator in the cycle and require higher temperatures energy source.
Industrial