Valve and subcooler for storing refrigerant
AssigneeTrane International Inc.
InventorsWilliam B. Fox, George M. Singh, Scott A. Munns
Life of this patent
Estimating the term…
Abstract
A reversible HVAC heating/cooling refrigerant system includes a novel valve system that allows an outdoor heat exchanger to function as a subcooler during a cooling or defrost mode and function as a receiver tank for storing excess liquid refrigerant during a heating mode. In the heating mode, a cooling expansion valve is kept slightly open to flood the subcooler with liquid refrigerant while a heating expansion valve is regulated to maintain a desired level of superheat at the suction side of the refrigerant system's compressor. The novel valve system also serves as a pressure relief valve to protect the subcooler from excess pressure caused by thermal expansion of liquid refrigerant trapped within the subcooler.
Claims19
A refrigerant system being operable in at least a heating mode and containing a refrigerant in heat transfer relationship with an outside fluid for ultimately heating a comfort zone or a process, the refrigerant system comprising:
- a heat exchanger system containing at least some of the refrigerant;
- a compressor periodically drawing the refrigerant at a suction pressure and discharging the refrigerant at a discharge pressure, thereby providing the refrigerant system with a high-pressure side and a low-pressure side;
- and
- a pressure relief valve defining an inlet and an outlet, the inlet is connected in fluid communication with the heat exchanger system, the outlet is connected in fluid communication with the low-pressure side, the pressure relief valve opens to release at least some of the refrigerant from within the heat exchanger system in response to the refrigerant within the heat exchanger system exceeding a maximum pressure limit, wherein the maximum pressure limit is even greater than the discharge pressure of the compressor.
A refrigerant system containing a refrigerant and being selectively operable in a heating mode and a cooling mode for respectively heating and cooling a comfort zone or a process, wherein the refrigerant system absorbs heat from an outside fluid when the refrigerant system is in the heating mode heating the comfort zone or process and releases heat to the outside fluid when the refrigerant system is in the cooling mode cooling the comfort zone or process, the refrigerant system comprising:
- an exterior heat exchanger system that includes a main coil and a subcooler, the exterior heat exchanger system is arranged to release heat to the outside fluid when the refrigerant system is in the cooling mode and absorb heat from the outside fluid when the refrigerant system is in the heating mode, the main coil defines a first main port and a second main port in refrigerant fluid communication with each other through the main coil, the subcooler defines a first subcooler port and a second subcooler port in refrigerant fluid communication with each other through the subcooler;
- and
- a valve system with pressure relief, the valve system defines a coil valve port and a subcooler valve port, the coil valve port is connected in refrigerant fluid communication with the second main port of the main coil, the subcooler valve port is connected in refrigerant fluid communication with the second subcooler port of the subcooler, the valve system has an open position and a closed position such that:
- a) in the open position, the valve system connects the coil valve port in refrigerant fluid communication with the subcooler valve port;
- b) in the closed position, the valve system substantially blocks refrigerant fluid communication therethrough between the coil valve port and the subcooler valve port;
- c) the valve system is in the open position when the refrigerant system is in the cooling mode;
- d) the valve system is in the closed position when the refrigerant system is in the heating mode while the refrigerant within the subcooler is below a predetermined pressure limit;
- and
- e) the valve system is in the open position when the refrigerant system is in the heating mode while the refrigerant within the subcooler is above the predetermined pressure limit.
A method of operating a refrigerant system that is selectively operable in a heating mode and a cooling mode, wherein the refrigerant system includes a main coil and a subcooler containing a refrigerant that is in heat transfer relationship with an outside fluid, the method comprising:
- in the cooling mode, releasing heat from the main coil and the subcooler to the outside fluid;
- in the heating mode, transferring heat from the outside fluid to the main coil as the refrigerant flows therethrough;
- in the heating mode, trapping within the subcooler at least some of the refrigerant, wherein most of the refrigerant trapped within the subcooler is in a liquid state;
- and
- releasing at least some of the refrigerant from within the subcooler if the refrigerant within the subcooler reaches a predetermined maximum pressure limit while still retaining substantially all of the refrigerant within the refrigerant system.
Dependencies are inferred from the claim text.