Summary: 3.1 Principle Of Refrigeration
3.1 Principle of Refrigeration[16]:
Mechanical refrigeration is done by three processes that are circulation, evaporation, and condensing a fixed supply of refrigerant in a closed system. Evaporation takes place at a low temperature and low pressure while condensation occurs at a high temperature and high pressure. Thus, it is possible to transfer heat from an area of low temperature (i.e., water storage tank) to an area of high temperature (i.e., environment).
Regarding to the fig 3.1, beginning the cycle at the evaporator inlet (1), the low-pressure liquid expands, absorbs heat, and evaporates, changing to a low-pressure gas at the evaporator outlet (2).The compressor (4) pumps this gas from the evaporator through the accumulator (3), increases its pressure, and discharges the high-pressure gas to the condenser (5). The accumulator is designed to protect the compressor by preventing slugs of liquid refrigerant from passing directly into the compressor. An accumulator should be included on all systems subjected to varying load conditions or frequent compressor cycling. In the condenser, heat is removed from the gas, which then condenses and becomes a high-pressure liquid. In some systems, this high-pressure liquid drains from the condenser into a liquid storage or receiver tank (6). On other systems, …show more content…
The compressor starts, and the cycle continues. In addition to the accumulator, a compressor crankcase heater (12) is included on many systems. This heater prevents accumulation of refrigerant in the compressor crankcase during the non-operating periods and prevents liquid slugging or oil pump-out on start-up. Additional protection to the compressor and system is afforded by a high- and low-pressure cut-out (13). This control is set to stop the compressor in the event that the system pressures rise above or fall below the design operating
Mechanical refrigeration is done by three processes that are circulation, evaporation, and condensing a fixed supply of refrigerant in a closed system. Evaporation takes place at a low temperature and low pressure while condensation occurs at a high temperature and high pressure. Thus, it is possible to transfer heat from an area of low temperature (i.e., water storage tank) to an area of high temperature (i.e., environment).
Regarding to the fig 3.1, beginning the cycle at the evaporator inlet (1), the low-pressure liquid expands, absorbs heat, and evaporates, changing to a low-pressure gas at the evaporator outlet (2).The compressor (4) pumps this gas from the evaporator through the accumulator (3), increases its pressure, and discharges the high-pressure gas to the condenser (5). The accumulator is designed to protect the compressor by preventing slugs of liquid refrigerant from passing directly into the compressor. An accumulator should be included on all systems subjected to varying load conditions or frequent compressor cycling. In the condenser, heat is removed from the gas, which then condenses and becomes a high-pressure liquid. In some systems, this high-pressure liquid drains from the condenser into a liquid storage or receiver tank (6). On other systems, …show more content…
The compressor starts, and the cycle continues. In addition to the accumulator, a compressor crankcase heater (12) is included on many systems. This heater prevents accumulation of refrigerant in the compressor crankcase during the non-operating periods and prevents liquid slugging or oil pump-out on start-up. Additional protection to the compressor and system is afforded by a high- and low-pressure cut-out (13). This control is set to stop the compressor in the event that the system pressures rise above or fall below the design operating