A reversible heat pump system with one bi-flow expansion device. A four-way valve in the refrigerant circuit may be configured in either a cooling mode or a heating mode. In the cooling mode, a compressor is operable to flow a refrigerant out a compressor outlet and through the bi-flow expansion device in a first direction. In the heating mode, the compressor is operable to flow the refrigerant out the compressor outlet and through the bi-flow expansion device in a second direction, opposite the first direction. Thus, only one thermal expansion device is needed for a reversible heat pump heating, ventilation, and air conditioning (HVAC) system without the need for bypass lines and check valves around the bi-flow expansion device. Further, if an accumulator is included before the compressor, the bi-flow expansion device may be controlled to store at least some refrigerant in the accumulator, thus allowing the evaporator superheat to be lower than if the accumulator were not used.

Provided is an expansion valve, including: a case having a valve chamber formed therein; and a valve element arranged in the valve chamber. The case includes: a side wall portion to which a first pipe is connected; and an end wall portion to which a second pipe is connected. The end wall portion has a fluid communication hole to be opened and closed by the valve element. The fluid communication hole is formed so that the following expression is satisfied: L<λ/2, where L represents an axial length of the fluid communication hole, and λ represents a resonance wavelength.

A header tube assembly is disclosed and can include an outer tube, an inner tube, and a flow valve. Each of the outer and inner tubes can include an open end and a closed end, as well as a plurality of apertures extending through a sidewall of the outer tube and inner tube, respectively. The apertures of the inner tube can permit a flow of refrigerant between an internal volume of the inner tube and a gap between the inner and outer tubes, and the apertures of the outer tube can permit a flow of refrigerant between the internal volume of the outer tube and a plurality of refrigerant circuits in a heat exchanger. The flow valve can be configured to selectively prevent refrigerant from flowing between the gap and the open end of the outer tube, depending on a direction of refrigerant flow through the header tube assembly.

A header tube assembly is disclosed and can include an outer tube, an inner tube, and a flow valve. Each of the outer and inner tubes can include an open end and a closed end, as well as a plurality of apertures extending through a sidewall of the outer tube and inner tube, respectively. The apertures of the inner tube can permit a flow of refrigerant between an internal volume of the inner tube and a gap between the inner and outer tubes, and the apertures of the outer tube can permit a flow of refrigerant between the internal volume of the outer tube and a plurality of refrigerant circuits in a heat exchanger. The flow valve can be configured to selectively prevent refrigerant from flowing between the gap and the open end of the outer tube, depending on a direction of refrigerant flow through the header tube assembly.

There is provided an expansion valve which, by moving the sub-valve in a valve housing, controls the flow rate of a refrigerant in a first flow direction and releases the refrigerant to flow in a second flow direction, wherein the sub-valve is reduced in weight and a valve port is provided with high accuracy. The sub-valve includes a guide member formed by press work and a valve seat member formed by cutting. The sub-valve is seated on a sub-valve seat of a valve seat ring when the pressure in a main valve chamber is high, and is moved away from the sub-valve seat when the pressure in the main valve chamber is low. The sub-valve is reduced in weight by forming the guide member by press work, and the valve port is formed with improved accuracy by forming the valve seat member by cutting.

A heat exchanger includes a refrigerant flow path into which a gas refrigerant flows from two gas-side inlets in the second row, that are positioned off from each other. Refrigerant flow paths from the two gas-side inlets converge in the one end portion. The refrigerant flow path connects to a heat-transfer pipe in the first row from the second row. The refrigerant flow path includes a refrigerant flow path which is formed in a range from the same stage as one of the gas-side inlets of the second row to the same stage as the other of the gas-side inlets of the second row, while being arranged along both ways between the one end portion and the other end portion in the first row, and the refrigerant flow path extends to a liquid-side outlet.

An HVAC system includes an electronic expansion valve, a motor, an obturator connected to the motor, the obturator being selectively movable in response to operation of the motor, a removable seat selectively received within a complementary portion of the electronic expansion valve, the removable seat being selectively movable in response to operation of the motor.

An electronic expansion valve is provided, wherein a piston component and a valve needle component are located at the same side of a valve core seat. When refrigerant flows forwards, the piston component closes the bypass through hole, the refrigerant flows to a side of the vertical connecting pipe via the valve core valve port, and the valve needle component moves in the axial direction to regulate an opening of the valve core valve port. When the refrigerant flows reversely, the piston component moves upwards in the axial direction to open the bypass through hole, and the refrigerant flows to a side of the transverse connecting pipe via the bypass through hole. The electronic expansion valve ensures that the valve needle component seals the valve core valve port easily in a high pressure state when the refrigerant flows forwards, and reduces axial and radial dimensions of the valve seat.

Provided is a highly efficient heating and cooling system. The heating and cooling system is provided with a cooling-purpose heat exchange section that, during cooling, subcools refrigerant, which is discharged from a compressor and liquefied by a heat source side heat exchanger, with an acceleration phenomenon of the refrigerant by rotating the refrigerant helically before the refrigerant reaches a pressure reducing device, and a heating-purpose heat exchange section that, during heating, partially vaporizes refrigerant, which is discharged from the compressor and liquefied by a use side heat exchanger, with an acceleration phenomenon of the refrigerant by rotating the refrigerant helically after the refrigerant has passed through the pressure reducing device and before the refrigerant reaches the heat source side heat exchanger, in which a heating-purpose coiled narrow tube of the heating-purpose heat exchange section has a flow passage that is formed to be wider than that of a cooling-purpose coiled narrow tube of the cooling-purpose heat exchange section.

An electronic expansion valve includes a valve needle screw assembly which includes a valve needle, a valve needle sleeve, a washer part, a spring, and a screw assembly. The valve needle sleeve includes a circumferential wall part and a fitting part. The inner diameter of the fitting part is smaller than the inner diameter of the circumferential wall part. The screw assembly includes a lower stopper part, a valve needle support part, and an upper stopper part. The lower stopper part abuts against the washer part. The valve needle support part abuts against the fitting part of the valve needle sleeve. The upper stopper part abuts against the spring. The distance between the valve needle support part and the washer part is D1; the distance between the valve needle support part and the upper end of the fitting part is D2; and D1≥D2.