An HVAC system having a fixed orifice expansion device coupled to an evaporator coil is provided. In one embodiment, an expansion device coupled to an evaporator coil includes a flow restrictor and an evaporator inlet manifold. The flow restrictor includes multiple fixed orifices aligned with the refrigerant distribution tubes to restrict flow of refrigerant from the evaporator inlet manifold into the refrigerant distribution tubes through the multiple fixed orifices. Additional systems, devices, and methods are also disclosed.

A valve device comprises a case comprising an open lower portion and an accommodation space formed therein, a base plate to cover the open lower portion of the case, an inlet pipe connected to the base plate and through which a refrigerant is introduced to the accommodation space, a boss installed to the base plate and comprising a plurality of refrigerant inlet and outlet holes through which the introduced refrigerant from the accommodation space is introduced and discharged, a plurality of inlet and outlet pipes respectively connected to the plurality of refrigerant inlet and outlet holes, and through which the refrigerant is introduced from the boss or discharged to the boss, and a pad comprising an open cavity formed therein to selectively open one refrigerant inlet and outlet hole, and a connection cavity formed therein to selectively connect two refrigerant inlet and outlet holes.

A valve device comprises a case comprising an open lower portion and an accommodation space formed therein, a base plate to cover the open lower portion of the case, an inlet pipe connected to the base plate and through which a refrigerant is introduced to the accommodation space, a boss installed to the base plate and comprising a plurality of refrigerant inlet and outlet holes through which the introduced refrigerant from the accommodation space is introduced and discharged, a plurality of inlet and outlet pipes respectively connected to the plurality of refrigerant inlet and outlet holes, and through which the refrigerant is introduced from the boss or discharged to the boss, and a pad comprising an open cavity formed therein to selectively open one refrigerant inlet and outlet hole, and a connection cavity formed therein to selectively connect two refrigerant inlet and outlet holes.

A refrigeration system includes an evaporator, a condenser, a compressor, a capillary tube, and an expansion device. The compressor is configured to circulate a refrigerant between the evaporator and the condenser. The capillary tube is configured to receive the refrigerant from the condenser. The expansion device is configured to receive the refrigerant from the capillary tube and provide the refrigerant to the evaporator. The expansion device is adjustable to control a flow of the refrigerant through the capillary tube.

A refrigeration system includes an evaporator, a condenser, a compressor, a capillary tube, and an expansion device. The compressor is configured to circulate a refrigerant between the evaporator and the condenser. The capillary tube is configured to receive the refrigerant from the condenser. The expansion device is configured to receive the refrigerant from the capillary tube and provide the refrigerant to the evaporator. The expansion device is adjustable to control a flow of the refrigerant through the capillary tube.

A heat source unit for an air conditioner that includes a refrigerant circuit includes: an external housing; and a cooling heat exchanger that is disposed in the external housing and that is connected to the refrigerant circuit. The external housing accommodates: a compressor connected to the refrigerant circuit; a heat source heat exchanger that is connected to the refrigerant circuit and that exchanges heat between a refrigerant circulating in the refrigerant circuit and a heat source; and an electric box. The electric box includes a top and a plurality of side walls; accommodates electrical components that control the air conditioner; and further includes an air passage that includes an air inlet and an air outlet. An air flow is induced through the air passage from the air inlet to the air outlet for cooling at least some of the electrical components.

A cooling system includes a subcooling heat exchange assembly, which controls magnitude of subcooling of refrigerant circulated through the cooling system. The subcooling heat exchange assembly includes a first fluid line fluidly coupled to an output of a condenser to enable a first portion of the refrigerant output from the condenser to flow through the first fluid line; a second fluid line fluidly coupled to the output of the condenser to enable a second portion of the refrigerant output from the condenser to flow through the second fluid line; and an expansion valve disposed along the second fluid line, in which the expansion valve exerts a first pressure drop on the second portion of the refrigerant that facilitates extracting heat from the first portion of the refrigerant flowing through the first fluid line using the second portion of the refrigerant flowing through the second fluid line when valve position of the expansion valve is greater than a threshold position. Additionally the cooling system includes a plurality of capillary expansion tubes fluidly coupled in parallel to an output of the first fluid line and that to exert a second pressure drop on the refrigerant circulated through the cooling system.

A cooling system includes an expansion valve configured to exert a first pressure drop on refrigerant circulated through the cooling system. The cooling system also includes a plurality of capillary expansion tubes fluidly coupled in parallel to an output of the expansion valve and configured to exert a second pressure drop on the refrigerant circulated through the cooling system. The cooling system also includes a controller communicatively coupled to the expansion valve, wherein the controller is configured to control magnitude of the first pressure drop by instructing the expansion valve to adjust the valve position based at least in part on refrigerant mass flow expected to be supplied to the expansion valve to facilitate substantially uniformly distributing the refrigerant mass flow between each of the plurality capillary expansion tubes.

In a heat pump device in which a compressor, a gas cooler, a refrigerant heat exchanger, a refrigerant expansion valve, and an evaporator are connected to configure a refrigerant circulation circuit, the heat pump device includes a buffer tank, one end being connected to the high-pressure side of the refrigerant expansion valve and arranged to store a refrigerant, and a first refrigerant pipe, one end being connected to the high-pressure side of the compressor and the other end connected to the low-pressure side of the evaporator and arranged to exchange heat with the buffer tank. The first refrigerant pipe includes a first control valve arranged between the high-pressure side of the compressor and the buffer tank to control opening and closing of the first refrigerant pipe, and a first flow rate regulator arranged between the buffer tank and the low-pressure side of the evaporator to control the refrigerant flow rate.

In a heat pump device in which a compressor, a gas cooler, a refrigerant heat exchanger, a refrigerant expansion valve, and an evaporator are connected to configure a refrigerant circulation circuit, the heat pump device includes a buffer tank, one end being connected to the high-pressure side of the refrigerant expansion valve and arranged to store a refrigerant, and a first refrigerant pipe, one end being connected to the high-pressure side of the compressor and the other end connected to the low-pressure side of the evaporator and arranged to exchange heat with the buffer tank. The first refrigerant pipe includes a first control valve arranged between the high-pressure side of the compressor and the buffer tank to control opening and closing of the first refrigerant pipe, and a first flow rate regulator arranged between the buffer tank and the low-pressure side of the evaporator to control the refrigerant flow rate.