Construction and Function (Direct Fired Absorption System)

Construction and Function (Direct Fired Absorption System) Points : construction and function (direct fired absorption system) Evaporator Refrigerant (water) of the evaporator is sprayed through special nozzle on the evaporator tube by refrigerant pump of refrigerant tank. Chilled water, which flows through the tube, has high temperature than that of the refrigerant so that the heat travels to the refrigerant of the outer surface of the tube to evaporate refrigerant, and chilled water cools down to lose its heat. The refrigerant evaporated travels to the absorber through the eliminator. Absorrer Lithium Bromide solution with proper temperature and density maintain a little pressure of the absorber than that of the evaporator. Therefore refrigerant vapor continues travels to the absorber from the evaporator to be absorbed in Lithium Bromide solution of the absorber. When refrigerant vapor is absorbed, the absorption heat travels to the chilled water inside the absorber tube. To absorb on the surface of the absorber tube group, Lithium Bromide solution is sprayed by special nozzle on the tube to let tube surface wet evenly by the solution pump. Low Temperature Heat Exchanger It is cross shape shell end tube model to elevate cycle efficiently by heat exchange between dilute solution and concentrated solution. Second Stage Generator In Second stage generator, heat energy (refrigerant vapor) is used to condense dilute solution up to medium density. Refrigerant vapor travels inside tube whereas the solution travels outside the tube. Condenser Refrigerant vapor evaporated in Second stage generator travels to the condenser through the eliminator, and cools down by cooling water to become the condensed refrigerant. Rich Temperature Heat Exchanger It is cross shape shell end tube model heat exchanger to elevate cycle efficiency by heat exchange between dilute solution and concentrated solution. It is located beside low temperature heat exchanger of clause (3). First Stage Generator It adopts cross shape flue tube liquid piping to use gas as a flue. When cooling down, it generates refrigerant vapor to heat and condense the solution, which has been supplied for high temperature heat exchanger, by combustion gas. When, heating refrigerant vapor, which has been generated from First stage generator, rave1s to Second stage generator to be condensed and return to the generator. Purge Device Purge device consist of extraction pipe, purge system, manual valve, check valve (or electric valve), oil trap, vacuum pump etc. Non condensation gas in the unit shall accumulate in the absorber with the lowest pressure. Extraction pipe is on the upper part of liquid, surface of the absorber, and used to start and stop purge after operation. Check valve (or electric vale) function as a safety device which prevents the air from flowing backward into the chiller-heater when power service being interrupted during vacuum pump operation. Oil trap is another safety device to prevent lubricant from flowing backward into the unit.