Abstract: A refrigeration cycle apparatus includes a refrigerant circuit, a controller, a bypass pipe, a refrigerant cooler, a second expansion device, and a controller temperature sensor. In a case where a temperature measured by the controller temperature sensor is lower than or equal to a set temperature in a state where an opening degree of the second expansion device is controlled to an instruction opening degree that is lower than or equal to a set opening degree, the controller is configured to perform foreign substance release control where the controller is configured to increase the opening degree of the second expansion device and then is configured to return the opening degree of the second expansion device to the instruction opening degree.

Abstract: A header includes a plurality of branch tubes and a header manifold. If refrigerant flowing into the header manifold forms a pattern of annular flow or churn flow, tips of the branch tubes inserted into the header manifold pass through a liquid-phase portion having a thickness ? [m] and reach a gas-phase portion. The thickness ? [m] of the liquid-phase portion is defined as ?=G×(1?x)×D/(4?L×ULS), where G is a flow speed [kg/(m2s)] of the refrigerant, x is a quality of the refrigerant, D is an inside diameter [m] of the header manifold, ?L is a liquid density [kg/m3] of the refrigerant, ULS is a reference apparent liquid speed [m/s] that is a maximum value within a range of variation in an apparent gas speed of the refrigerant flowing into a flow space of the header manifold. The reference apparent liquid speed ULS [m/s] is defined as G(1?x)/?L.

Abstract: A refrigeration cycle apparatus includes a main circuit through which refrigerant circulates and in which a compressor, a condenser, a first expansion device, a centrifugal gas-liquid separator that separates refrigerant into gas refrigerant and liquid refrigerant by using centrifugal force, and an evaporator are connected by refrigerant pipes; and a bypass that returns the gas refrigerant obtained through the separation by the gas-liquid separator to a suction side of the compressor. The gas-liquid separator includes a cylindrical container, an inflow pipe, a gas outflow pipe, and a liquid outflow pipe. The main circuit includes a second expansion device provided between the liquid outflow pipe of the gas-liquid separator and the evaporator. The gas refrigerant discharged from the gas outflow pipe of the gas-liquid separator flows into the bypass, and the bypass is provided with a third expansion device.

Abstract: In an air-conditioning apparatus in which air sucked into a casing of an outdoor unit by a fan is discharged from an upper portion of the casing, each of liquid header portions is configured to be connected with each of heat transfer tubes of a plurality of divided regions formed by dividing the outdoor heat exchangers in an up and down direction. Further, a shunt is configured to supply two-phase refrigerant, in which quality is adjusted by a gas-liquid separator, to each of the liquid header portions. To each of the liquid header portions, the shunt supplies the two-phase refrigerant of the amount corresponding to the air quantity of the divided region connected to each of the liquid header portions.

Abstract: In order to provide a correction device that enables the accuracy of the linearity between sensor output values and flow rate values in a flow rate sensor, there are provided a sensitivity correction function storage unit that stores a sensitivity correction function in which at least a portion of sensitivity correction values are set to different values in accordance with the sensor output values output from a flow rate sensor in an initial state in which the sensitivity coefficient is set to an initial value, a sensitivity setting unit that sets the sensitivity coefficient based on the initial values and on the sensitivity correction function, and then adjusts the sensitivity of the flow rate sensor, and a coefficient calculation unit that calculates a post-correction flow rate characteristic function based on function correction values that are decided in accordance with the flow rate values output post sensitivity correction.

Abstract: In a flow path forming structure, axial runout of a shaft relative to a central axis generated when the shaft is inserted into the flow path is suppressed. This structure includes a flow path along which a fluid passes, and a shaft body that is inserted into the flow path. An upstream side of the shaft body and an inner circumferential surface of the flow path have a plurality of contact positions at different phases, and a downstream side of the shaft body and an inner circumferential surface of the flow path have a plurality of contact positions at different phases. The fluid flows through gaps between the shaft body and the inner circumferential surface. The contact positions on one of the upstream and downstream sides are at different phases from all of the contact positions on the other one of the upstream and downstream sides.

Abstract: A liquid level detection device detecting a liquid level of a liquid in a container includes a heater configured to heat the container, a plurality of temperature sensors provided at different heights of the container, and configured to detect a surface temperature of the container, and a controller configured to detect the liquid level of the liquid in the container, based on the surface temperature of the container detected by the plurality of temperature sensors when the heater is caused to heat.

Abstract: A refrigerant distributor branches refrigerant flowing in a refrigerant circuit into three, and includes a first bifurcate flow divider including a first pipe portion forming one inflow port, a second pipe portion and a third pipe portion forming two outflow ports communicating with the inflow port of the first pipe portion, and a second bifurcate flow divider including a fourth pipe portion forming one inflow port, and a fifth pipe portion and a sixth pipe portion forming two outflow ports communicating with the inflow port of the fourth pipe portion. The outflow port of the third pipe portion and the inflow port of the fourth pipe portion communicate with each other, and an angle ? formed by a first plane passing through the first bifurcate flow divider and a second plane passing through the second bifurcate flow divider is between 60 and 120 degrees.

Abstract: A refrigeration cycle apparatus includes a main circuit through which refrigerant circulates and in which a compressor, a condenser, a first expansion device, a centrifugal gas-liquid separator that separates refrigerant into gas refrigerant and liquid refrigerant by using centrifugal force, and an evaporator are connected by refrigerant pipes; and a bypass that returns the gas refrigerant obtained through the separation by the gas-liquid separator to a suction side of the compressor. The gas-liquid separator includes a cylindrical container, an inflow pipe, a gas outflow pipe, and a liquid outflow pipe. The main circuit includes a second expansion device provided between the liquid outflow pipe of the gas-liquid separator and the evaporator. The gas refrigerant discharged from the gas outflow pipe of the gas-liquid separator flows into the bypass, and the bypass is provided with a third expansion device.

Abstract: The air-conditioning apparatus includes the plurality of heat source apparatuses; a plurality of indoor units each including an indoor heat exchanger and each configured to perform one of cooling and heating operations; a relay device connected to the heat source apparatuses by a high pressure pipe and a low pressure pipe and configured to distribute refrigerant flowing therein from the heat source apparatuses to the plurality of indoor units; and a controller configured to control operations of the heat source apparatuses. The relay device includes a relay device temperature detecting unit configured to detect a temperature of the refrigerant flowing through the bypass pipe. During the heating main operation, the controller changes an opening degree of each of the outdoor side expansion devices based on the temperature detected by the relay device temperature detecting unit.

Abstract: An air-conditioning apparatus includes a heat source unit, a plurality of indoor units, and a relay unit. The heat source unit includes a heat-source-side flow control valve connected to a heat-source-side heat exchanger, a bypass pipe connected in parallel to the heat-source-side heat exchanger, a bypass flow control valve provided in the bypass pipe, and a gas-liquid separating unit configured to, when refrigerant flows out to the high-pressure pipe, mix refrigerant in a liquid state flowing through the heat-source-side heat exchanger and refrigerant in a gas state flowing through the bypass pipe and cause mixed refrigerant to flow out to the high-pressure pipe, and configured to, when refrigerant flows in from the low-pressure pipe, separate the refrigerant flowing in from the low-pressure pipe into refrigerant in a liquid state flowing into the heat-source-side heat exchanger and refrigerant in a gas state flowing into the bypass pipe.

Abstract: An air-conditioning apparatus that includes a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger, which are connected by pipes, in which the outdoor heat exchange unit includes a first outdoor heat exchanger, a first flow rate control device, a second outdoor heat exchanger, a second flow rate control device, a bypass pipe, the second outdoor heat exchanger, the second flow rate control device, a third flow rate control device, and a flow control device.

Abstract: A heat exchanger includes a plurality of heat transfer tubes, a first header, a second header, and a plurality of fins. The heat exchanger constitutes a portion of a refrigeration cycle circuit in which refrigerant circulates. The second header includes a header pipe. The header pipe has an entrance portion. A bypass pipe is disposed between the entrance portion and the first header and configured to bypass refrigerant. The bypass pipe protrudes into the header pipe to be connected to the header pipe. The bypass pipe is provided with a flow control mechanism configured to control a flow rate of refrigerant.

Abstract: A refrigeration cycle apparatus includes a refrigerant circuit, a controller, a bypass pipe, a refrigerant cooler, a second expansion device, and a controller temperature sensor. In a case where a temperature measured by the controller temperature sensor is lower than or equal to a set temperature in a state where an opening degree of the second expansion device is controlled to an instruction opening degree that is lower than or equal to a set opening degree, the controller is configured to perform foreign substance release control where the controller is configured to increase the opening degree of the second expansion device and then is configured to return the opening degree of the second expansion device to the instruction opening degree.

Abstract: The air-conditioning apparatus includes a heat exchanger including a plurality of heat transfer tubes and a header manifold an axial fan and a refrigerant circuit. When the distance from the center of the flow space in the horizontal plane is represented on a scale of 0 to 100%, where 0% represents the center of the flow space and 100% is the position of the wall surface of the header manifold, among the plurality of branch tubes located within a height range that allows the blade to rotate, the majority of the branch tubes located at or below the height of the boss are connected to the header manifold such that their distal ends are positioned at 0 to 50% of the distance from the center, and the majority of the branch tubes located above the height of the boss are connected to the header manifold such that their distal ends are positioned at more than 50% of the distance from the center.

Abstract: A heat source side unit connected to load side units by pipes and constituting a refrigerant circuit, includes a compressor that compresses refrigerant and discharges the refrigerant, a heat source side heat exchanger that serves as an evaporator or a radiator, a gas-liquid separator that separates inflow refrigerant into liquid refrigerant and gas refrigerant, a liquid refrigerant outlet from which the liquid refrigerant flows out being connected to a connecting pipe at a refrigerant inflow side in a case where the heat source side heat exchanger serves as the evaporator, a sixth connecting pipe that connects a gas refrigerant outlet of the gas-liquid separator from which the gas refrigerant flows out to a pipe at a refrigerant outflow side in a case where the heat source side heat exchanger serves as the evaporator, and an expansion device that controls passage of refrigerant in the sixth connecting pipe.

Abstract: A header includes a plurality of branch tubes and a header manifold. If refrigerant flowing into the header manifold forms a pattern of annular flow or churn flow, tips of the branch tubes inserted into the header manifold pass through a liquid-phase portion having a thickness ? [m] and reach a gas-phase portion. The thickness ? [m] of the liquid-phase portion is defined as ?=G×(1?x)×D/(4?L×ULS), where G is a flow speed [kg/(m2s)] of the refrigerant, x is a quality of the refrigerant, D is an inside diameter [m] of the header manifold, ?L is a liquid density [kg/m3] of the refrigerant, ULS is a reference apparent liquid speed [m/s] that is a maximum value within a range of variation in an apparent gas speed of the refrigerant flowing into a flow space of the header manifold. The reference apparent liquid speed ULS [m/s] is defined as G(1?x)/?L.

Abstract: A thermal flow meter is provided that can accurately correct zero point and span errors, which change depending on an ambient temperature, independently of a fluid type. The thermal flow meter includes: a flow path through which measuring target fluid flows; an upstream side electrical resistive element provided on the upstream side of the flow path; a downstream side electrical resistive element provided on the downstream side of the flow path; and a flow rate calculation part that calculates a flow rate of the measuring target fluid on the basis of an upstream side voltage that is a voltage applied to the upstream side electrical resistive element, a downstream side voltage that is a voltage applied to the downstream side electrical resistive element, and the thermal conductivity of the measuring target fluid.

Abstract: In order to reduce a flow rate error over the entire range of a sensor output value even when the relationship between the sensor output value and a flow rate value is poor in linearity, a flow rate sensor correction device includes: a sensitivity setting part adapted to set a sensitivity coefficient on the basis of an initial value and a sensitivity correction value and adjust the sensitivity of the flow rate sensor; a function calculation part adapted to calculate a corrected flow rate characteristic function on the basis of a function correction value, which is determined on the basis of the flow rate value, and a standard flow rate characteristic function; and a function modification part adapted to make a function storage part store, as a flow rate characteristic function, a final flow rate characteristic function based on the corrected flow rate characteristic.

Abstract: A target condensing temperature and a target evaporating temperature are changed in accordance with a load of each load side unit obtained by using load detection means, and an operating frequency of a compressor and a rotation speed of a fan are controlled such that a condensing temperature obtained by using temperature detection means coincides with the target condensing temperature and an evaporating temperature obtained by using the temperature detection means coincides with the target evaporating temperature.