The body of a chiller is constructed by an evaporator, the lower part of an absorber, a condenser, upper part of a low-temperature generator, a high-temperature generator, a high-temperature heat exchanger, a low-temperature heat exchanger, solution (dilute and concentrated solution), a refrigerant pump, a steam trap and a heat retriever.
Refrigerants which are evaporated after cooling cold water within an evaporator are absorbed into a highly concentrated absorption liquid within an absorber. At this time, the absorption liquid becomes weakened (a dilute solution).
The solution whose concentration becomes weakened within the absorber (a dilute solution) comes into a high-temperature generator through a low-temperature heat exchanger and a high-temperature heat exchanger at higher temperature by means of a solution pump and is heated with high-temperature and high-pressure steam and is concentrated to middle density.
The middle-concentrated solution comes into a low-temperature generator through a high-temperature heat exchanger and is concentrated to become a thick solution (a concentrated solution) by refrigerant vapor generated at a high-temperature generator. After this, the solution returns to an absorber at a lower temperature through a low-temperature heat exchanger, repeating the absorption process.
In the process, steam supplied to a high-temperature generator heats solution of the generator, passes through a drain heat retriever installed to produce heat exchanging with the solution through a steam trap of a drain outlet, and then discharges steam condensate after lowering its temperature to less than 95℃, improving the chiller efficiency by enhancing drain heat recovery.