Comparison between centrifugal refrigeration unit using R11 and R134a;

Theory and preventing method of surge for centrifugal chillers;

Characteristics comparison of centrifugal chillers using HCFC123 or HFC134a;

Based on the theoretical study,and by practical analysis in detail,the effective ways of ensuring unit running were provided,which has good energy saving effects on centrifugal chiller.

The two substitutive refrigerants HFC134a and HCFC123 in centrifugal chillers were described and the safety performance,efficiency and some other factors of the two refrigerants were synthetically compared.

Through analyzing the constitution of condenser of centrifugal chillers,calculated the velocity of flow of cooling water by the pressure difference of cooling water in tube in accordance with Kern equation of shell and tube heat exchanger, then acquired the heat transfer coefficient of the condenser, finally, got out the condenser heat load and refrigeration capacity of centrifugal chillers.

The principle of centrifugal chillers is introduced to verify that chillers with multiple stages can avoid surge effectively and can be used in ice storage system.

Affection of pressure difference of cooling water on refrigerating output of centrifugal water chillers;

Selection of refrigerant substitute in R12 centrifugal water chillers in service;

Analyses the performance parameters including refrigerating effect, COP value, noise level, size and weight of centrifugal water chillers, presents author s opinion for configuration design of these units.

Selection of high-efficiency centrifugal water chillers with systems approach;

According to the special requirement of refrigerant alternative in centrifugal water chillers, a new alternative, LXR1, was developed as the same thermal performance with R12.