System and Method to Eliminate High Pressure Surges in HVAC Systems

Abstract

A system and method are disclosed for relieving high pressure within an HVAC system. A bypass line is provided that can direct refrigerant away from a condenser within the HVAC system. The bypass line can direct the refrigerant toward an inlet to the evaporator within the HVAC system. Other locations of bypass lines can be used as well. A controller for the HVAC system can control access to the bypass line and measure pressure within the system. An orifice can be provided within the bypass line to help relieve pressure within the HVAC system.

What is claimed is: 
     
         1 . An HVAC system comprising an evaporator, condenser, pressure sensor, and compressor, the system comprising:
 a bypass line, the bypass line operable to direct at least some refrigerant away from the condenser inlet and toward the evaporator inlet; and   a controller communicatively coupled to the pressure sensor and the bypass line, the controller operable to open the bypass line when the pressure within the liquid line reaches a set value;   wherein the bypass line comprises an orifice, the orifice operable to relieve pressure within the HVAC system.   
     
     
         2 . The HVAC system of  claim 1  wherein the condenser comprises a microchannel condenser. 
     
     
         3 . The HVAC system of  claim 1  wherein the controller opens the bypass line by opening a solenoid valve. 
     
     
         4 . The HVAC system of  claim 1  wherein the bypass line comprises a pressure regulating valve. 
     
     
         5 . The HVAC system of  claim 1  further comprising a second pressure sensor. 
     
     
         6 . The HVAC system of  claim 1  further comprising a distributor. 
     
     
         7 . The HVAC system of  claim 1  wherein the pressure sensor is located proximate the discharge line of the compressor. 
     
     
         8 . The HVAC system of  claim 1  wherein the bypass line comprises an expansion device and a solenoid valve. 
     
     
         9 . A method of operating an HVAC system comprising:
 receiving, at a controller, a signal to start the HVAC system;   starting, by the controller, the HVAC system;   receiving, at the controller, a pressure measurement within the HVAC system;   sending, by the controller, a message to open a valve in a bypass line when the pressure measurement is above a set value, thereby directing at least some refrigerant away from a condenser inlet and toward an evaporator inlet, wherein the bypass line comprises an orifice; and   sending, by the controller, a message to close the valve when a predetermined event has occurred.   
     
     
         10 . The method of  claim 9  wherein the HVAC system comprises a microchannel condenser. 
     
     
         11 . The method of  claim 9  wherein the predetermined event is a period of time. 
     
     
         12 . The method of  claim 9  wherein the predetermined event occurs when the pressure within the HVAC system drops below the set value. 
     
     
         13 . The method of  claim 9  wherein the valve is a solenoid valve. 
     
     
         14 . The method of  claim 9  wherein the bypass line comprises an expansion device and a solenoid valve. 
     
     
         15 . The method of  claim 9  wherein in the pressure measurement is received from a pressure sensor proximate the discharge line of the compressor. 
     
     
         16 . The method of  claim 9  wherein HVAC system comprises a distributor. 
     
     
         17 . A method of relieving pressure within an HVAC system comprising:
 starting the HVAC system;   receiving a pressure notification when pressure within the HVAC system exceeds a set value;   opening a bypass line in response to the pressure notification, the bypass line capable of diverting at least some refrigerant away from a condenser inlet and toward an evaporator inlet, the bypass line comprising a valve and an orifice; and   closing the bypass line when a predetermined event has occurred.   
     
     
         18 . The method of  claim 17  wherein the HVAC system comprises a microchannel condenser. 
     
     
         19 . The method of  claim 17  wherein the HVAC system comprises a fin tube evaporator. 
     
     
         20 . The method of  claim 17  wherein the predetermined event is a period of time.