Hvac&r system valving

Abstract

An HVAC&R system is disclosed that utilizes energy-efficient valving. The valving controls the flow of refrigerant and may be adapted for evaporator or condenser applications, on both AC systems and heat pumps (as well as chillers and other refrigeration systems). The valving may provide simultaneous and individualized control of flow through individual coils or groups of coils for improved control of evaporation, condensation, defrosting and so forth. In some configurations a common sensor may be shared between individual coils or groups of coils and may provide sensed parameters to control circuitry for controlling the valving. Other configurations may include bypass valving to direct fluid around the flow control valving. In yet other configurations, a valve may be used to bypass tapped vapor around a heat exchanger functioning as an evaporator.

1 . A heat exchanger system comprising:
 a plurality of valves for simultaneously and independently metering fluid flow through heat exchanger tubes in a first direction;   bypass valving coupled fluidly around the plurality of valves;   control circuitry coupled to the bypass valving and configured to selectively open the bypass valving when the fluid is flowing through the heat exchanger in a second direction opposite to the first direction to direct the fluid around the plurality of valves.   
     
     
         2 . The system of  claim 1 , wherein the plurality of valves comprises electromechanical valves each configured to meter flow of the fluid through an individual heat exchanger tube. 
     
     
         3 . The system of  claim 1 , wherein the plurality of valves comprises electromechanical valves each configured to meter flow of the fluid through a group of heat exchanger tubes. 
     
     
         4 . The system of  claim 1 , wherein the control circuitry is configured to circulate the fluid through the bypass valving when the fluid is flowing in the second direction and the heat exchanger system is operating in an air conditioning mode. 
     
     
         5 . The system of  claim 1 , wherein the control circuitry is configured to circulate the fluid through the plurality of valves when the fluid is flowing in the second direction and the heat exchanger system is operating in a heat pump mode. 
     
     
         6 . The system of  claim 1 , wherein the control circuitry is configured to circulate the fluid through the plurality of valves when the fluid is flowing in the first direction and the heat exchanger system is operating in a heat pump mode. 
     
     
         7 . The system of  claim 1 , wherein the control circuitry is configured to circulate the fluid through the plurality of valves when the heat exchanger system is operating in a defrost mode. 
     
     
         8 . The system of  claim 1 , wherein the control circuitry is operably coupled to the plurality of valves and configured to meter the fluid flow to reduce frosting on the heat exchanger tubes. 
     
     
         9 . A heat exchanger system comprising:
 a plurality of valves each fluidly coupled to a respective heat exchanger tube or tube group and each configured to simultaneously and independently meter fluid flow through the respective heat exchanger tube or tube group; and   bypass valving coupled fluidly around the plurality of valves and configured to selectively bypass the plurality of valves in response to a signal from control circuitry.   
     
     
         10 . A method for promoting heat exchange to or from a fluid, the method comprising:
 circulating a refrigerant through a plurality of valves to regulate flow through heat exchanger tubes in a first direction when the heat exchanger is functioning as an evaporator;   circulating the refrigerant through the plurality of valves to regulate flow through the heat exchanger tubes in a second direction to defrost the heat exchanger tubes; and   bypassing the plurality of valves by circulating the refrigerant through a bypass valving coupled fluidly around the plurality of valves to flow refrigerant through the heat exchanger tubes in a second direction opposite to the first direction when the heat exchanger is functioning as a condenser.   
     
     
         11 . A heat exchanger system comprising:
 a plurality of flow paths for circulating a fluid through a heat exchanger, each of the plurality of flow paths having a first valve for metering fluid flow through the flow path; and   a valve bank fluidly coupled to each of the plurality of flow paths and configured to selectively direct the fluid from each of the plurality of the flow paths to a sensor.   
     
     
         12 . The system of  claim 11 , wherein the valve bank comprises a plurality of second valves, each configured to direct the fluid from an individual flow path of the plurality of flow paths to the sensor. 
     
     
         13 . The system of  claim 11 , wherein the sensor is configured to sense a pressure or temperature of the fluid. 
     
     
         14 . The system of  claim 11 , comprising control circuitry configured to control each of the first valves based on a sensed parameter received from the sensor. 
     
     
         15 . The system of  claim 11 , wherein each of the plurality of flow paths comprise a tube or group of tubes within the heat exchanger. 
     
     
         16 . A heat pump system comprising:
 a compressor configured to compress a refrigerant;   a heat exchanger configured to evaporate the refrigerant in a heat pump mode of operation and to condense the refrigerant in an air conditioning mode of operation;   an accumulator configured to store the refrigerant in the heat pump mode of operation; and   bypass valving coupled fluidly around the heat exchanger and configured to tap vapor phase refrigerant upstream of the heat exchanger and to circulate the tapped vapor phase refrigerant to the accumulator in the heat pump mode of operation.   
     
     
         17 . The system of  claim 16 , wherein the compressor is configured to receive the refrigerant from the accumulator in the heat pump mode of operation and in the air conditioning mode of operation. 
     
     
         18 . The system of  claim 16 , comprising an additional heat exchanger configured to evaporate the refrigerant in the air conditioning mode of operation and to condense the refrigerant in the heat pump mode of operation. 
     
     
         19 . The system of  claim 18 , wherein the accumulator is configured to receive the refrigerant from the bypass valving and from the heat exchanger in the heat pump mode of operation and wherein the accumulator is configured to receive the refrigerant from the additional heat exchanger in the air conditioning mode of operation. 
     
     
         20 . The system of  claim 18 , comprising an expansion device configured to reduce pressure of the condensed refrigerant in the heat pump mode of operation and wherein the bypass valving is configured to tap the condensed refrigerant upstream of the expansion device in the heat pump mode of operation.