Hvac systems and methods with improved stabilization

Abstract

Systems and methods are presented for improving stabilization of a heating, ventilating, and air conditioning (HVAC) system. More specifically, the systems and methods include a heat-flow modulator for regulating an exchange of thermal energy between a flow of refrigerant and a sensory bulb. The exchange of thermal energy allows an expansion valve to respond to a refrigerant temperature using an actuator, which is coupled to the sensory bulb. The heat-flow modulator is formed of a body that includes a first contact surface and a second contact surface. The first contact surface is thermally-coupled to a suction line of the HVAC system, which conveys the flow of refrigerant. The second contact surface is thermally-coupled to the sensory bulb. Other systems and methods are presented.

1 . A heating, ventilating, and air conditioning system comprising:
 a closed-conduit refrigeration circuit comprising:   an expansion valve fluidly coupled to a sensory bulb, the expansion valve configured to regulate refrigerant flow within the closed-conduit refrigeration circuit,   an evaporator fluidly-coupled to the expansion valve via a refrigeration line,   a compressor fluidly-coupled to the evaporator via a suction line, and   a condenser fluidly-coupled to the compressor and to the expansion valve, and   a heat-flow modulator, the heat-flow modulator comprising a modulator body having a first contact surface and a second contact surface, the first contact surface thermally-coupled to the suction line and the second contact surface thermally-coupled to the sensory bulb.   
     
     
         2 . The system of  claim 1 , wherein the first contact surface is formed on the modulator body as a first concave portion and the second contact surface is formed as a second concave portion facing away from the first concave portion. 
     
     
         3 . The system of  claim 1 , wherein the modulator body has a rectilinear cross-section. 
     
     
         4 . The system of  claim 1 , further comprising at least one bracket member for urging a portion of the suction line toward the first contact surface of the heat-flow modulator and for urging at least a portion of the sensory bulb toward the second contact surface of the heat-flow modulator. 
     
     
         5 . The system of  claim 1 , wherein the modulator body is formed from a thermally-insulating material. 
     
     
         6 . The system of  claim 1 , wherein the modulator body is formed from a thermally-insulating material, and wherein the thermally-insulating material has a thermal conductivity less than 1 W/(m·K). 
     
     
         7 . The system of  claim 1 , wherein the modulator body is formed from a thermally-conducting material. 
     
     
         8 . The system of  claim 1 , wherein the modulator body is formed from a thermally-conducting material, and wherein the thermally-conducting material has a thermal conductivity greater than 10 W/(m·K). 
     
     
         9 . The system of  claim 1 , wherein the compressor comprises a plurality of compressors that form a tandem configuration within the closed-conduit refrigeration circuit. 
     
     
         10 . The system of  claim 1 , wherein the condenser comprises a microchannel condenser. 
     
     
         11 . A method for stabilizing suction pressure within a heating, ventilating, and air conditioning (HVAC) system, the system having a closed-conduit refrigeration circuit, the method comprising:
 using a heat-flow modulator to exchange heat between refrigerant in a suction line and a sensory bulb;   fluidly-coupling the sensory bulb to an expansion valve, wherein the expansion valve is configured to regulate refrigerant flow within the closed-conduit refrigeration circuit;   altering a flow of refrigerant through the expansion valve in response to heat exchanged between the sensory bulb and the heat-flow modulator; and   wherein the expansion valve is configured to meter the flow of refrigerant to the evaporator.   
     
     
         12 . The method of  claim 11 , wherein the heat-flow modulator comprises a modulator body having a first contact surface and a second contact surface, the first contact surface thermally-coupled to the suction line and the second contact surface thermally-coupled to the sensory bulb. 
     
     
         13 . The method of  claim 11 , wherein the step of using a heat-flow modulator to exchange heat comprises the step of directing heat along a predetermined thermal flow path of the heat-flow modulator. 
     
     
         14 . The method of  claim 11 , wherein the step of using the heat-flow modulator to exchange heat comprises flowing heat from the suction line through a first contact surface of the heat-flow modulator. 
     
     
         15 . The method of  claim 11 , wherein the step of using the heat-flow modulator to exchange heat comprises flowing heat from the suction line through the first contact surface of the heat-flow modulator and through a second contact surface into the sensory bulb. 
     
     
         16 . The method of  claim 11 , wherein the step of using the heat flow modulator to exchange heat between refrigerant in the suction line and the sensory bulb comprises:
 flowing heat from the suction line through the first contact surface of the heat-flow modulator and through the second contact surface into the sensory bulb; and   flowing heat from the suction line through at least one bracket into the sensory bulb.   
     
     
         17 . The method of  claim 11 , wherein the step of altering the flow of refrigerant through the expansion valve comprises:
 decreasing an occlusion of a fluid-flow orifice in the expansion valve in response to heat entering the sensory bulb; and   increasing the occlusion of the fluid-flow orifice in the expansion valve in response to heat leaving the sensory bulb.   
     
     
         18 . The method of  claim 11 , wherein the heat-flow modulator is selected from the group of a thermally-insulating material and a thermally-conducting material. 
     
     
         19 . The method of  claim 11 , wherein the heat-flow modulator comprises thermally-conducting material. 
     
     
         20 . The method of  claim 11 , wherein the step of using a heat-flow modulator to exchange heat between refrigerant in a suction line and a sensory bulb comprises adjusting the thickness or area of the heat-flow modulator to achieve a desired heat flow modulation.