Patent ID: 9657978
Date: 2017-05-23
CPC Classifications: F25B,F28D,F28F

Claim:
1. A heating, ventilating, air conditioning or refrigeration system comprising: a condenser configured to condense refrigerant vapor into a condensate; a flash tank configured to receive the refrigerant as the condensate from the condenser and to at least partially vaporize the refrigerant; an evaporator configured to receive refrigerant from the flash tank and to vaporize the refrigerant; a compressor configured to receive condensate vapor from the evaporator and to compress the refrigerant vapor for return to the condenser; an electronically controlled flash tank feed valve disposed between the condenser and the flash tank, configured to control a flow of condensate from the condenser to the flash tank; sensors configured to sense pressure and temperature of the condensate as the condensate flows from the condenser; and a control system coupled to the flash tank feed valve and configured to regulate opening and closing of the flash tank feed valve to control the flow of condensate based upon subcooling of the condensate, the control system being coupled to the sensors and configured to receive signals from the sensors representative of pressure and temperature and to compute the subcooling of the condensate based upon the signals for control of the flash tank feed valve, wherein the control system is coupled to the compressor and is configured to receive a feed forward parameter from the compressor indicative of compressor capacity, and wherein the control system is configured to regulate opening and closing of the flash tank feed valve based upon the feed forward parameter, such that the control system anticipates changes in the subcooling of the condensate.