Abstract: A refrigeration cycle apparatus includes a compressor, a condenser, a first subcooling device that subcools a refrigerant by exchanging heat with the air, a second subcooling device that performs a heat exchange between refrigerant streams that have been branched by a branch pipe, thereby subcooling one of the refrigerant streams, a flow control device that adjusts a flow rate of the second stream of the refrigerant and passes this refrigerant through the second subcooling device, a bypass path that allows the refrigerant passing through the flow control device and the second subcooling device to flow therethrough, an expansion valve, an evaporator, and a controller configured to control an amount of heat exchanged in the first subcooling device and an amount of heat exchanged in the second subcooling device based on a temperature of the air.

Abstract: To provide a refrigerating cycle apparatus capable of improving cooling ability by water spray to perform an efficient operation while suppressing decrease in collected power by an expander. The refrigerating cycle apparatus includes: a first compressor that compresses the refrigerant; an expander that decompresses and expands the refrigerant to collect power for expansion; a second compressor that is driven by the power collected by the expander to further compresses the refrigerant compressed by the first compressor to transmit it to a main radiator; a heat exchanger having an intercooler that cools the refrigerant compressed by the first compressor and a main radiator that cools the refrigerant compressed by the second heat exchanger to transmit it to the expander; indoor heat exchangers that heat the refrigerant decompressed by the expander; and a water spray apparatus that sprays water onto the outer surface of the intercooler and the main radiator.

Abstract: A multi-chamber type air-conditioning apparatus is provided in which a refrigerant whose effect on human bodies is a concern is prevented from leaking into a room or the like in which an indoor unit is installed, simultaneous operation of cooling and heating is possible, and performance deterioration by a refrigerant flow control device or drop of the cooling capacity of the indoor unit can be prevented.

Abstract: A refrigeration cycle device circulates a refrigerant, which is a zeotropic refrigerant mixture. In a refrigeration cycle, a compressor, a condenser, an expansion valve, and an evaporator are connected by a refrigerant pipe. The refrigeration cycle device calculates a circulation composition value of the refrigerant based on states before and after the refrigerant temperature and the refrigerant pressure change during the operation of the refrigeration cycle, calculates dT for calibrating a second temperature sensor and dP for calibrating a pressure sensor, based on a reference composition value and the circulation composition value of the refrigerant, corrects the value of the temperature of the refrigerant on an outlet side based on dT, corrects the value of the pressure of the refrigerant based on dP, and operates the refrigeration cycle.

Abstract: A heat source-side refrigerant circuit A including a compressor 11, an outdoor heat exchanger 13, a first refrigerant branch portion 21 connected to the compressor 11, a second refrigerant branch portion 22 and a third refrigerant branch portion 23 connected to the outdoor heat exchanger 13, a first refrigerant flow rate control device 24 provided between branch piping 40 and the second refrigerant branch portion 22, intermediate heat exchangers 25n connected at one side thereof to the first refrigerant branch portion 21 and the third refrigerant branch portion 23 via three-way valves 26n and connected at the other side thereof to the second refrigerant branch portion 22, and second refrigerant flow rate control devices 27n provided between the respective intermediate heat exchangers 25n and the second refrigerant branch portion 22, and user-side refrigerant circuits Bn having indoor heat exchangers 31n connected respectively to the intermediate heat exchangers 25n are provided, and at least one of water and

Abstract: Energy saving of a refrigerating cycle device is achieved by equalizing heat-medium inlet temperatures of a plurality of use-side heat exchangers.

Abstract: In a refrigeration cycle device, a design volume ratio, obtained by dividing a stroke volume of a sub-compressor by a stroke volume of an expander, is set to be smaller than (DE/DC)×hE?hF)/(hB?hA). With an operating efficiency being the maximum in an operating range allowed to be set of the refrigeration cycle device, DE is a density of a refrigerant, which has flowed out from a radiator, DC is a density of the refrigerant, which has flowed out from an evaporator, hE is a specific enthalpy of the refrigerant flowing into the expander, hF is a specific enthalpy of the refrigerant, which has flowed out from the expander, hA is a specific enthalpy of the refrigerant sucked by a main compressor, and hB is a specific enthalpy of the refrigerant at an intermediate position of a compression process of the main compressor.

Abstract: A refrigerating and air-conditioning apparatus, which includes a compressor, a condenser, an expansion device, and an evaporator, has a refrigeration cycle configured by these components being connected by a refrigerant pipe, and uses a non-azeotropic refrigerant mixture as a refrigerant circulating through the refrigeration cycle, includes operating state detection means which detect a pressure of the refrigerant at the compressor, a temperature of the refrigerant at the compressor, and a rotation speed of the compressor, output detection means which detects an output of the compressor, and composition detection means which calculates a correlation between the pressure of the refrigerant at the compressor, the temperature of the refrigerant at the compressor, the rotation speed of the compressor, the output of the compressor, and a refrigerant composition and retains data indicating the correlation.

Abstract: There are provided a plurality of use-side heat exchangers, inter-heat-medium heat exchangers, heat medium flow path switching devices, which switch flow paths, and pumps, which feed heat media to these paths; the inter-heat-medium heat exchangers heat or cool a heat medium by exchanging heat between the heat medium and a heat source fluid fed from a heat source apparatus. About half of the plurality of use-side heat exchangers are preheated or precooled, and the remaining use-side heat exchangers which are not preheated or precooled exchange heat media with use-side heat exchangers that have been preheated or precooled and that are not yet started to operate, suppressing energy consumed for preheating or precooling.

Abstract: A computing device calculates a quality of a refrigerant flowing out of a second expansion device on the basis of an inlet liquid enthalpy calculated on the basis of a temperature of the refrigerant flowing into the second expansion device and a saturated gas enthalpy and a saturated liquid enthalpy calculated on the basis of a temperature of the refrigerant flowing out of the second expansion device or a pressure of the refrigerant sucked into a compressor; calculates a liquid-phase concentration and a gas-phase concentration of the refrigerant flowing out of the second expansion device on the basis of the temperature of the refrigerant flowing out of the second expansion device and the pressure of the refrigerant sucked into the compressor; and calculates a composition of the refrigerant circulating in a refrigeration cycle on the basis of the calculated quality, liquid-phase concentration, and gas-phase concentration.

Abstract: An air-conditioning apparatus is capable of suppressing refrigerant flow noise regardless the refrigerant state of an inlet of an expansion mechanism. In parallel to a flow control valve, an opening and closing valve that opens and closes a refrigerant passage and an expansion mechanism having porous bodies capable of passing a refrigerant therethrough are connected in series with each other. In a heating mode, in the case where a controller stops an operation of one or more of a plurality of indoor units and causes the other indoor unit(s) to operate, the flow control valve of the stopped indoor unit is fully closed and the opening and closing valve of the stopped indoor unit is opened.

Abstract: A first cycle, in which a first medium is circulated, employs a compressor, a first heat exchanger structured with an air heat exchanger, a second heat exchanger, and a third heat exchanger. A second cycle, in which a second medium is circulated and heat is exchanged with the first medium through the second heat exchanger, employs indoor units, each having a fan. A third cycle, in which the second medium is circulated and heat is exchanged with the first medium through the third heat exchanger, shares the indoor units with the second cycle. Flow path switching valves switch flow paths between the second cycle and third cycle. Before the first heat exchanger is defrosted, a halted indoor unit is filled with the second medium in the third cycle with its fan being halted. The third heat exchanger functions as an evaporator during a defrosting operation.

Abstract: In an air-conditioning apparatus that uses a refrigerant, which operates in a transcritical cycle, and refrigerating machine oil, which has low miscibility with the refrigerant, in a refrigerant circuit for a refrigeration cycle connected to a compressor, a radiator, an expansion mechanism, and an evaporator, the air-conditioning apparatus includes a flow regulating mechanism provided in the refrigerant circuit, and flow control means that controls the flow regulating mechanism. If a refrigerant flow velocity at an outlet side of the radiator is lower than a predetermined threshold value, the refrigerant flow velocity at the outlet side of the radiator is increased by the flow control means so that oil-return operation that returns the refrigerating machine oil discharged from the compressor to the compressor is performed for at least a predetermined time period.

Abstract: A refrigeration cycle apparatus increases the cooling capacity even under overload conditions in a refrigeration cycle apparatus that uses a refrigerant which undergoes transition to a supercritical state and in which the high-pressure side enters a supercritical state. A refrigeration cycle apparatus adjusts a high-pressure-side pressure of a refrigerant flowing through a main refrigerant circuit by causing a controller to control an opening degree of a second expansion valve and a heat transfer area of a radiator.

Abstract: A refrigeration cycle apparatus achieves efficient operation by constantly recovering power in a wide operating range. The refrigeration cycle apparatus regulates a pressure of a high pressure side by changing either one or both of an opening degree of the intermediate-pressure bypass valve and an opening degree of the pre-expansion valve on the basis of a density ratio that is obtained from an inflow refrigerant density of the expander and an inflow refrigerant density of the sub-compressor in an actual operating state and a design volume ratio that has been expected at the time of design and that is obtained from a stroke volume of the sub-compressor, a stroke volume of the expander, and a ratio of a flow rate of the refrigerant flowing to the sub-compressor.

Abstract: Disclosed is a positive displacement expander equipped with an expansion mechanism in which power is generated using fluid energy produced while a high-pressure fluid, supplied to a plurality of expansion chambers partitioned by an orbiting scroll or a rolling piston, is being expanded and decompressed. The expander includes a communicating pipe that allows each of the expansion chambers to communicate with an expander discharge side and an opening and closing device disposed on the communicating pipe. When supply of the high-pressure fluid is stopped, the opening and closing device is opened by the time when high and low pressures between each of the expansion chambers and the expander discharge side are equalized, thus stopping the orbiting scroll or the rolling piston at a predetermined position so that an expander obtains sufficient driving force when resuming.

Abstract: A heat pump capable of operating in a high COP state even if influx temperature of a medium to be heated flowing into the radiators has increased. The heat pump includes a compressor, a first radiator, a second radiator, an expansion valve, and an evaporator sequentially connected by refrigerant piping to form a first refrigeration cycle, in which a first refrigerant circulates in the first refrigeration cycle, and in which the first radiator and the second radiator are serially connected. A first heat exchange unit that heats the first refrigerant is provided in a refrigerant piping at a refrigerant inlet side of the second radiator, and a second heat exchange unit that cools the first refrigerant is provided in a refrigerant piping at a refrigerant outlet side of the second radiator.

Abstract: An air-conditioning apparatus in which a heat source unit and a relay unit are connected by two pipings, and in which a hot water supply function can be readily added. The relay unit includes a connection circuit between a first branching unit and a second connecting piping that is capable of connecting a water heat exchanger that exchanges heat between a refrigerant and water.

Abstract: A refrigeration cycle apparatus includes a refrigeration cycle formed by a first compressor, a radiator, an expander that expands a refrigerant that has passed through the radiator, and an evaporator. A bypass piping has one end connected to a discharge piping of the expander and the other end connected to a suction piping of the first compressor. A pressure sensor and a temperature sensor detect the suction pressure and suction temperature of the expander as physical quantities of the refrigerant to be sucked into the expander. A bypass valve controls the flow rate of the refrigerant. A control device determines the appropriate discharge pressure of the expander on the basis of the suction pressure and suction temperature of the expander, and opens the bypass valve when the pressure at which the expander discharges the refrigerant is higher than the determined appropriate discharge pressure.

Abstract: In a refrigeration cycle apparatus that recovers power in an expander, obtaining a refrigeration cycle apparatus that is capable of reliably starting up the expander compared to conventional refrigeration cycle apparatuses. The refrigeration cycle apparatus includes a refrigerant circuit having a first compressor, a radiator, an expander and an evaporator connected in series with a piping; and a second compressor disposed between the first compressor and the radiator, the second compressor being driven by power recovered by the expander. The second compressor being a positive displacement compressor. The refrigeration cycle apparatus, further including a pressure regulating device (a bypass and an on-off valve) that maintains a pressure on a discharge side of the second compressor to be lower than a pressure on a suction side of the second compressor at least until the second compressor is started up.