AIR CONDITIONING SYSTEM WITH VAPOR INJECTION COMPRESSOR

摘要

An air conditioning system can be toggled between a heating mode, in which heat is withdrawn from a source (e.g., a geothermal source) and deposited into a conditioned space (e.g., a building), and a cooling mode, in which heat is withdrawn from the conditioned space and deposited into the source. The air conditioning system uses a combination of efficiency-enhancing technologies, including injection of superheated vapor into the system's compressor from an economizer circuit, adjustable compressor speed, the use of one or coaxial heat exchangers and the use of electronic expansion valves that are continuously adjustable from a fully closed to various open positions. A controller may be used to control the system for optimal performance in both the heating and cooling modes, such as by disabling the economizer circuit and vapor injection when the system is in the cooling mode.

主权项

1. An air conditioning system comprising:
a refrigerant circuit containing a quantity of refrigerant; a compressor operable to compress the refrigerant from a low pressure vapor at a compressor inlet to a high pressure vapor and a compressor outlet, the compressor further comprising a vapor injection inlet functionally interposed between the compressor inlet and the compressor outlet; a load heat exchanger operable to exchange heat; a source heat exchanger operable to exchange heat; a reversing valve functionally interposed between the compressor and the load and source heat exchangers, the reversing valve toggleable between a cooling mode and a heating mode wherein:
in the cooling mode, the reversing valve routes the refrigerant from the compressor outlet to the source heat exchanger and from the load heat exchanger to the compressor inlet, andin the heating mode, the reversing valve routes the refrigerant from the compressor outlet to the load heat exchanger and from the source heat exchanger to the compressor inlet; an economizer heat exchanger functionally interposed between the load heat exchanger and the source heat exchanger; an economizer expansion valve positioned to receive a portion of the refrigerant diverted from a main refrigerant flow path between the load and source heat exchangers when the reversing valve is in the heating mode, the economizer expansion valve operable to receive the portion of the refrigerant in a subcooled liquid phase and discharge the portion of the refrigerant in a mixed vapor/liquid phase to the economizer heat exchanger, the economizer heat exchanger operable to exchange heat from the main refrigerant flow to the portion of the refrigerant to convert the portion of the refrigerant to a superheated vapor phase, and to discharge the superheated vapor refrigerant to the vapor injection inlet of the compressor; and a primary expansion valve functionally interposed between the economizer heat exchanger and the source heat exchanger, the primary expansion valve operable to receive the refrigerant in a subcooled liquid phase and discharge the refrigerant in a vapor mixture phase.