Abstract: A thermal management system for a gas turbine engine includes a first heat exchanger and a second heat exchanger in communication with a bypass flow through an inlet. A valve is operable to selectively communicate the bypass flow to either the first heat exchanger or the second heat exchanger through the inlet.

Abstract: A system and method for converting otherwise wasted energy produced in the form of heated gases as a byproduct of an industrial process into electrical energy. At least some waste gases are diverted from a typical exhaust structure through a heat exchanger and back into the exhaust structure. The amount of gases flowing through the heat exchanger is monitored and regulated by a controller. A heat source liquid is simultaneously circulated under pressure through the heat exchanger and through an organic Rankine cycle system. The amount of heat source liquid being circulated is also monitored and regulated by the controller. The ORC system converts the heat from the heat source liquid into electricity.

Abstract: The invention relates to a heat exchanger (1) for indirect heat exchange comprising a tube bundle (10), formed from a plurality of tubes helically coiled around a core tube (100), for receiving a first medium, a shell (20). which encloses the tube bundle (10) and defines a shell space (200) surrounding the tube bundle (10), for receiving a second medium, and a liquid distributor (40) for distributing in the shell space (200) a stream (S), conveyed in the shell space (200), of the second medium in the form of a liquid (F). According to the invention a control means (33) for controlling distribution in the shell space (200) of an additional, further stream (S?) of liquid (F), and/or for controlling distribution of stream (S) of liquid (F) in the shell space (200).

Abstract: A method, system and apparatus for providing temperature control of compressed gases between stages of a multiple-stage compressor, by selectively manipulating a valve which can cause at least a portion of the compressed gases to flow through an air-cooled heat exchanger.

Abstract: The invention relates to a shell and tube heat exchanger (1) having a helical tube bundle (10) within a shell (20), that defines a shell space (200) surrounding the tube bundle (10). The tubes are helically coiled about a core pipe (100) in such a manner that there is formed at least one first section (11) and at least one second section (12), separate from the first section, that surrounds the first section (11). The two sections (11, 12) have in each case at least one associated inlet (E, E?) such that the two sections (11, 12) are able to be charged separately with the first medium.

Abstract: A heating system for a beverage processing system with a beverage flow consisting of a beverage to be processed, with a secondary flow of a heat conducting medium, where the secondary flow is passed in a closed secondary circuit, with at least one heat exchanger, through which the secondary current flows and is arranged such that it is able to transfer heat to the beverage flow. A combustion system is arranged in the secondary flow such that heat generated by the combustion system can be passed on to the heat conducting medium. Also, a method of heating beverages with a combustion system.

Abstract: The injection molding device of the present invention is provided with a supply pipe which supplies a heat medium to a mold, a discharge pipe which discharges the heat medium from the mold, a mold temperature adjustor to which the supply pipe and the discharge pipe are connected to adjust the temperature of the mold, and a discharge rate adjusting unit which is provided with a variable flow control valve installed on the discharge pipe to adjust a flow rate of the heat medium, a discharge pipe variable flow control valve bypass pipe for bypassing the variable flow control valve and a discharge pipe bypass on-off valve installed on the bypass pipe to change a flow rate of the heat medium and which is installed at a position upstream from the mold temperature adjustor on the discharge pipe.

Abstract: A heat dissipation device includes a receiving body and a blower. The receiving body includes a recessed body. The recessed body includes a first sidewall, a second sidewall opposite to the first sidewall, and a bottom connecting the first sidewall to the second sidewall. The blower is arranged on the bottom. The blower includes a casing, an air supply pipeline communicating with the casing, and an air blocking plate between the casing and the air supply pipeline. Two opposite ends of the air blocking plate respectively contact with the first sidewall and the second sidewall, such that the recessed body is separated into a first recessed area and a second recessed area. The first recessed area receives the casing, and the second recessed area receives the air supply pipeline.

Abstract: An exhaust heat recovery device comprises: a heat exchanger for recovering heat from exhaust gas; a second flow channel for circulating the exhaust gas during exhaust heat non-recovery; a branching member for connecting an inlet of the heat exchanger and an inlet of the second flow channel; a merging member for connecting an outlet of the heat exchanger and an outlet of the second flow channel; a valve for blocking the outlet of the second flow channel; and a valve chamber for housing the valve. The branching member is comprised of a single chamber formed by joining together a first chamber half in which one inlet is provided, the first chamber half being draw-molded from a blank, and a second chamber half in which two outlets are provided, the second chamber half being draw-molded from a blank.

Abstract: A vehicle thermal management system is provided that includes two or more heat exchangers configured in a non-stacked arrangement, where separate air inlets corresponding to each of the heat exchangers allow a direct intake of ambient air. Active louver systems consisting of sets of adjustable louvers and a control actuator are used to control and regulate air flowing directly into one or more of the heat exchangers, where the adjustable louvers are either adjustable between two positions, i.e., opened and closed, or adjustable over a range of positions. Air ducts may be used to couple the output from one heat exchanger to the input of a different heat exchanger.

Abstract: A refrigeration cycle apparatus including a heat source side heat exchanger including a first heat exchanger and a second heat exchanger connected in parallel; an air-sending device that supplies air, which is an object to be heat exchanged in the first heat exchanger and the second heat exchanger, in a variable manner; solenoid valves that each opens and closes a refrigerant passage of the first heat exchanger and the second heat exchanger; a third refrigerant circuit that is parallelly connected to the first heat exchanger and the second heat exchanger; and a flow control valve that controls the flow rate of the refrigerant flowing in the third refrigerant circuit. The refrigeration cycle apparatus can improve continuity of control of a heat exchange capacity of a heat source side heat exchanger.

Abstract: An apparatus for recovering energy from freezer exhaust includes a heat exchanger disposed for coaction with a freezer in a first atmosphere, the heat exchanger having a first heat transfer surface in communication with the freezer exhaust and the first atmosphere, and a second heat transfer surface in communication with the freezer exhaust and the first atmosphere; a discharge conduit in communication with the first and second heat transfer surfaces, and extending to a second atmosphere remote from the first atmosphere; a first valve assembly disposed for coaction with the first and second heat transfer surfaces, the first valve assembly movable to direct a flow of the freezer exhaust to a select one of the first and second heat transfer surfaces or optionally to direct the flow to both the first and second heat transfer surfaces; and a first blower to move a flow of the first atmosphere to a select one or both of the first and second heat transfer surfaces for heat transfer with the flow of the freezer exha

Abstract: Multiple projections are provided at a flow-change portion, which corresponds to such a portion of a wall surface of an A/C casing, at which velocity gradient of air current becomes larger in an area adjacent to the wall surface, in order to decrease aerodynamic sound generated by disturbed air current.

Abstract: One embodiment exemplarily described herein can be generally characterized as a heat sink for an electronic component. The heat sink may include a main body thermally contactable to an electronic component; at least one fin thermally contacted with the main body; and a confining member. The at least one fin and the confining member may be cooperatively engaged such that the at least one fin is moveable between a first position relative to a longitudinal axis of the main body and a second position relative to the longitudinal axis of the relative to the main body.

Abstract: An apparatus for facilitating servicing of a liquid-cooled electronics rack is provided. The apparatus includes a coolant tank, a coolant pump in fluid communication with the coolant tank, multiple parallel-connected coolant supply lines coupling the coolant pump to a coolant supply port of the apparatus, and a coolant return port and a coolant return line coupled between the coolant return port and the coolant tank. Each coolant supply line includes a coolant control valve for selectively controlling flow of coolant therethrough pumped by the coolant pump from the coolant tank. At least one coolant supply line includes at least one filter, and one coolant supply line is a bypass line with no filter. When operational, the apparatus facilitates filling of coolant into a cooling system of a liquid-cooled electronics rack by allowing for selective filtering of coolant inserted into the cooling system.

Abstract: Material withdrawal apparatus, methods, and systems of regulating material inventory in one or more units are provided. A material withdrawal apparatus includes a heat exchanger and transport medium junction configured to provide transport medium to transport the withdrawn material from the unit to the heat exchanger. Another material withdrawal apparatus includes a heat exchanger and shock coolant junction configured to provide shock coolant to the material withdrawn from the unit. Another material withdrawal apparatus includes a heat exchanger, shock coolant junction, and transport medium junction. Another embodiment of a material withdrawal apparatus includes a vessel and shock coolant junction. Another material withdrawal apparatus includes a vessel and transport medium junction. The vessel includes a wall, liner with heat insulating refractory material, fill port, and a discharge port.

Abstract: The present invention relates to a device for building ventilation, having heat recapturing, wherein the heat of the room air that is fed outside is recaptured, and cold outside air being fed inside can be preheated by means of the recaptured heat.

Abstract: A reliable, leak-tolerant liquid cooling system with a backup air-cooling system for computers is provided. The system may use a vacuum pump and a liquid pump and/or an air compressor in combination to provide negative fluid pressure so that liquid does not leak out of the system near electrical components. Alternatively, the system can use a single vacuum pump and a valve assembly to circulate coolant. The system distributes flow and pressure with a series of pressure regulating valves so that an array of computers can be serviced by a single cooling system. The system provides both air and liquid cooling so that if the liquid cooling system does not provide adequate cooling, the air cooling system will be automatically activated. The heat may be removed from the building efficiently with a cooling tower.

Abstract: Condenser (1) having a sub cooling unit, comprising a gas inlet collector (2); a sub cooler collector (4) connected to the gas inlet collector (2) by at least one condensing conduit (12) having a condensing surface, said condensing surface condensing the gaseous refrigerant (10a) to liquid refrigerant (10b), said sub cooler collector (4) collecting the liquid refrigerant (10b); and a liquid refrigerant collector (6) connected to the sub cooler collector (4) by at least one cooling conduit (14) having a cooling surface, said cooling surface cooling down the liquid refrigerant (10b); the at least one condensing conduit (12) discharging into the top of the sub cooler collector (4) and the at least one cooling conduit (14) joining at the bottom of the sub cooler collector (4) so that the sub cooler collector (4) allows for compensation of the gaseous refrigerant (10a).

Abstract: A thermal management and heat transfer system for light fixtures. And in particular, light fixtures comprising LED lights requiring lower temperatures than those required by incandescent of neon based light fixtures. The heat transfer includes taking advantage of the thermal updrafts caused by free convection of waste heat to cool the fixture.

Abstract: A system is provided for cooling at least one heat producing device in an aircraft that includes, but is not limited to at least one coolant circuit. A coolant absorbs heat from the heat producing device and dissipates heat, by way of a heat dissipation device, to the surroundings of the aircraft. A temperature spreading device reduces the temperature of the coolant in a feed line of the coolant circuit and increases the heat dissipation temperature of the heat dissipation device relative to the temperature of the coolant in a return line of the coolant circuit. In this manner ram air ducts that are commonly used in the state of the art or systems that consume pre-cooled air can be avoided, which in particular when the aircraft is situated on the ground on hot days can render avionics cooling or the like difficult.

Abstract: A heat dissipation device includes a centrifugal fan, a fan duct and a fin assembly. The centrifugal fan has an air outlet. The fan duct is fixed to the air outlet. The fan duct includes a plurality of guiding plates spaced from each other. A channel is defined between every two neighboring guiding plates. Each of the guiding plates includes a near end near the air outlet and a far end opposite to the near end away from the air outlet. The widths of the channels at the near ends are larger comparing to the portions of the air outlet when having smaller quantity of airflow, and are smaller comparing to the portions of the air outlet when having large quantity of airflow. Widths of the channels at the far ends are equal to each other. The fin assembly is positioned at the far ends of the guiding plates.

Abstract: A vehicle thermal management system is provided that includes two or more heat exchangers configured in a non-stacked arrangement, where separate air inlets corresponding to each of the heat exchangers allow a direct intake of ambient air. Corresponding to each heat exchanger is a set of adjustable louvers that control ambient air flowing directly into the heat exchanger. The adjustable louvers may be adjustable between two positions; fully opened or fully closed. Alternately, the adjustable louvers may be adjustable over a range between fully opened and fully closed. Alternately, each set of adjustable louvers may be comprised of multiple groups of independently controllable louvers. Air ducts may be used to couple the output from one heat exchanger to the input of a different heat exchanger.

Abstract: A cooling module and a water-cooled motor system using the same are provided. The cooling module comprises a main body and a first flow passage assembly. The main body comprises a first lateral portion and a second lateral portion opposite the first lateral portion. The first flow passage assembly, disposed in the main body, comprises a first flow passage and a second flow passage. The first flow passage has a first end and a second end, wherein the first end is adjacent to the first lateral portion, and the second end is adjacent to the second lateral portion. The second flow passage has a third end and a fourth end, wherein the third end is connected to the second end of the first flow passage, and the fourth end is adjacent to the first lateral portion.

Abstract: This invention relates to the use of system thermal energy generated by equipment, such as an ultrasound sensing device, to transfer heat to the peripherals/sensors/probes under user control. This is accomplished by recycling the heat generated by the system and used that to keep the peripheral/sensor/probe warm.

Abstract: An electronic device includes a housing, a printed circuit board received in the housing, a plurality of heat-generating elements mounted on the printed circuit board and a heat dissipation device secured to an end of the housing. The heat dissipation device includes a fan module and a bracket securing the fan module onto the housing. The housing includes a first side wall and a second side wall with a passage defined therebetween. The heat-generating elements are positioned in the passage. The fan module includes first and second fans arranged side by side. The bracket defines first and second openings corresponding to the first and second fans respectively for air flow generated by the fans. An air baffle is pivotally connected to the bracket and capable of turning to close a corresponding opening corresponding to a failing fan upon failure of either the first or second fan.

Abstract: A heat exchanger apparatus includes a housing that defines a flow passage for a first fluid. The housing has a housing fluid inlet and a housing fluid outlet communicating with the flow passage. A first heat exchanger is located within the flow passage of the housing between the housing fluid inlet and the housing fluid outlet. The first heat exchanger has a plurality of channels for transmitting a second fluid through the first heat exchanger. The heat exchanger apparatus also includes a flow diverter in the flow passage, between the housing fluid inlet and the first heat exchanger, for diverting some of the first fluid to a by-pass region of the flow passage that by-passes the first heat exchanger. As well, a flow control device is in communication with the housing fluid inlet and controls a volume and location of the first fluid entering the flow passage.

Abstract: A heat exchanger is disclosed that includes heat exchange elements made from a sheet having a plurality of hollow fins. In certain embodiments, the finned sheet is refolded and sealed at a first edge and a second edge to form an interior volume having an inlet manifold adjacent to the first edge, an outlet manifold adjacent to the second edge, and an opening that is opposite the refold of the finned sheet. In certain embodiments, a flow divider is located in the interior volume between the inlet manifold and the outlet manifold with interior tips of the hollow fins in contact with the flow divider. A base element is coupled over the opening of the interior volume, the base element comprising an inlet and an outlet positioned in fluid communication with the inlet manifold and the outlet manifold, respectively.

Abstract: A heat dissipation device includes a heat sink and a fan duct. The fan duct includes a cover and a baffle. The cover includes a top plate, a first sidewall and a second sidewall respectively extending from opposite sides of the top plate. The baffle is located between the first sidewall and the second sidewall of the cover and pivotally contacts the first and second sidewalls. The baffle forms an angle with the top plate and is rotatable relative to the first and second sidewalls to adjust the angle between the baffle and the top plate.

Abstract: A device for influencing the flow in the area of a pipe manifold plate of a tube bundle heat exchanger with an outer channel encased by an outer sheath for a heat carrier medium, with a number of inner tubes extending axially parallel to the outer sheath through the outer channel, together forming an inner channel, each supported on the end side in the pipe manifold plate, with an inlet or outlet common for all inner tubes designed in a exchanger flange and a common outlet or respectively inlet designed in a connection piece for a product with at least one displacement body. A guide ring forms radially inside with its inner contour the required and proven flow environment for the displacement body.

Abstract: A heat exchanger structure including multiple fluid circuits, through which respective streams of a first fluid pass from a stream inlet to a stream outlet to transfer heat to or from a second medium. The fluid circuits are arranged into at least a first group and a second group, at least the first group consisting essentially of only fluid circuits that perform substantially similarly according to at least one selected performance criterion. A control sensor for at least the first group generates a signal representative of a parameter of the first fluid in the associated group. A valve for at least the first group is in fluid communication with of all the streams of the associated group so as to be able to control the flow of fluid through the streams of the associated group in parallel.

Abstract: The electronic device includes a heat generator 54, a heat radiator 58, and a heat radiation material 56 disposed between the heat generator 54 and the heat radiator 58 and including a plurality of linear structures 12 of carbon atoms and a filling layer 14 formed of a thermoplastic resin and disposed between the plurality of linear structures 12.

Abstract: A condensing system is provided. The condensing system may include baffle plate units having a substantially flat surface and openings configured for cooling fluid to flow through; and baffles attached to the baffle plate unit, the baffles oriented at an acute angle with respect to the baffle plate unit, the baffles having a flat surface and figured to diffuse a cooling fluid into a thin, turbulent film at a similar acute angle. A method of condensing a fluid is provided. The method includes defining a path for the fluid to be condensed to flow; spraying a cooling fluid against a baffle thereby creating a turbulent film of cooling fluid in the path for the fluid to be condensed and orienting some of the baffles to create a film of cooling fluid oriented in one direction and orienting other baffles to create a film of cooling fluid in a second direction wherein the path of the fluid to be condensed causes the fluid to be condensed to flow over films oriented in both the first and second directions.

Abstract: One or more heat exchangers mounted in a duct have heat transfer cooling passages therein and a variable geometry flow restrictor is integral with each of the heat exchangers. An annular slide valve axially translatable within the duct is operable to open and close or vary a variable area between the heat exchangers and one of inner and outer casings bounding the duct. The heat exchangers may be being circumferentially distributed around an annular duct and include radial or circumferentially curved heat transfer tubes or vanes.

Abstract: An air conditioner includes an outdoor heat exchanger that is divided into a plurality of unit paths. at least two of the plurality of unit paths are connected in series or parallel to one another according to cooling/heating operation, so that it is possible to vary the number or length of paths through which a refrigerant passes. Since the number or length of paths is properly selected and used, it is possible to enhance efficiency.

Abstract: A thermal management apparatus includes an electrohydrodynamic fluid accelerator in which an emitter electrode and another electrode are energizable to motivate fluid flow. The emitter electrode is a layered structure including an electrode core material and an outermost coating that is susceptible to micro-cracking or corona erosion. A barrier material is provided in a sublayer to protect the underlying electrode core material. An adhesion promoting layer may be used between the barrier material and the electrode core material or between other layers of the structure. solid solution. A method of making an EHD product includes positioning the layered electrode relative to another electrode to motivate fluid flow when energized.

Abstract: According to one embodiment of the present invention, there is provided cooling apparatus. The cooling apparatus comprises an outlet for supplying chilled liquid, an inlet for receiving return chilled liquid, a free cooling system for providing first cooling to the return chilled liquid, a chiller unit for further cooling the first cooled return liquid to a predetermined temperature, a pressure difference sensor for measuring the pressure difference between the chilled liquid supplied at the outlet and the return liquid received at the inlet, and a flow control module for maintaining a predetermined pressure difference between the liquid supplied at the outlet and the return liquid received at the inlet.

Abstract: An adjustable cooling mechanism is provided. The cooling mechanism may include: a hollow member surrounding, at least in part, a machine to be cooled; the hollow member having holes oriented at the machine; an outlet configured to outlet a compressed fluid from the machine; a conduit connecting the outlet to an interior of the hollow member; and a throttling mechanism configured to throttle a fluid moving through the holes.

Abstract: A heat exchange chamber for liquid state cooling fluid is provided, which comprises a flow resistance, the flow resistance is sited inside a cavity at a position proximate to an inlet. In other words, the flow resistance is sited between the inlet and a thermal dissipation device. The flow resistance narrows down a flow channel from the inlet to the cavity, and it raises the resistance of the cooling fluid before the cooling fluid flows through a thermal dissipation device. Because of the heat exchange chamber for liquid state cooling fluid, the cooling fluid could be distributed uniformly through the dissipating heat device.

Abstract: A heater-cooler system for a barrel of an extruder is disclosed. The system includes a heater adapted to be in thermal communication with at least a portion of a barrel of an extruder. The system further includes a shroud assembly that defines a cavity. The shroud assembly encloses the heater. The shroud assembly has an intake port and an exhaust port. A valve is in fluid communication with the exhaust port. The valve is moveable between an open position and a closed position. When the valve is in the closed position the exhaust port is substantially sealed. When the valve is moved between the closed position and the open position or is in the open position the cavity is in fluid communication an area outside of the cavity through the exhaust port.

Abstract: A cooler having a first component made of at least one of steel, stainless steel, plastic and ceramic. A second component may be made of aluminum, wherein the two components may be connected to each other in a connecting area via a friction stir weld joint.

Abstract: A device with a heat exchanger with a feed pipe for a medium leading from a medium inlet to the heat exchanger entrance and with a discharge pipe leading away from the heat exchanger exit is characterized in that it has a first bypass from the medium inlet to the discharge pipe and a second bypass from the feed pipe to the medium outlet and valves, so that the medium can also flow from the heat exchanger exit to the heat exchanger entrance.

Abstract: Apparatus to control a temperature of a device that includes: a thermal head adapted to be thermally contacted to the device; a combined path to the thermal head; a first path maintained at a first temperature and connected to the combined path; a second path maintained at a second temperature different from the first temperature and connected to the combined path; a third path connected to the combined path; a pump assembly operable to circulate thermal transfer fluid: from the thermal head, through each of the first, second and third paths, from each of the first, second and third paths, through the combined path, and from the combined path, to and through the thermal head; and a valve assembly operable to control amounts of thermal transfer fluid that flow into the first and second paths, thereby controlling the temperature.

Abstract: A heat exchanger for a sealed enclosure is disclosed that includes a separator plate and a motor secured to the separator plate. The motor rotates a shaft having opposed ends, an ambient air impeller is secured to one end of the shaft, and an enclosed air impeller is secured to an opposite end of the shaft. An ambient shell secured to the separator plate substantially encloses the ambient air impeller and an enclosed air shell secured to the separator plate substantially encloses the enclosed air impeller. Each shell has an axial opening and a radial opening and a plurality of curvilinear fins extending between the separator plate and the shells. Airflow through the enclosed air shell imparts heat to the fins which transfer the heat for rejection by the airflow through the ambient air shell.

Abstract: Airflow in a computer chassis may be enhanced or reduced to affect cooling of heat generating devices using an ionic air moving device. A plurality of ionic air moving devices enhance or reduce airflow through a plurality of fluidically parallel airflow zones of the computer chassis in an airflow direction established by a nonionic air moving device. Each ionic air moving device comprises an ion emitter electrode disposed a spaced distance from a collector electrode, wherein a controller independently controls an electrical potential between the emitter and collector electrodes of each ionic air moving device for affecting the rate of airflow through one or more of the plurality of airflow zones.

Abstract: An internal heat exchanger assembly for an air conditioning system, having a substantial cylindrical cavity in which a helical coil tube is coaxially disposed within the cylindrical cavity. A bleed valve assembly is incorporated into the helical coiled tube, in which the bleed valve assembly is adapted to open at a predetermined differential pressure between the high pressure side and low pressure side of the internal heat exchanger. The bleed valve selectively bleeds refrigerant from the high pressure side to the low pressure side, thereby increasing the pressure and mass flow rate of the refrigerant to the suction side of a compressor to reduce or eliminate compressor rattle.

Abstract: The invention relates to a fail-safe rotary actuator (1) for a coolant circuit, in particular for a coolant circuit of an internal combustion engine (2) having a plurality of sub-circuits (3) and (4), includes a coolant delivery pump (5) for circulating the coolant within the coolant circuit, and having a rotary-slide housing (8) which has a plurality of housing pass-through openings (6) and (7) and in which at least one rotary slide (9) having at least one rotary slide pass-through opening (11) and (12) is rotatably supported, wherein the housing pass-through openings (6) and/or (7) are fluidly connected to at least one sub-circuit (3) and/or (4), and can be brought into at least partial coincidence with the rotary slide pass-through openings (11) and/or (12) by a rotary motion of the rotary slide (9), wherein a thermostat valve (13) opens a flow path running parallel to the rotary slide (9) from one of the sub-circuits (3) or (4) to the coolant delivery pump (5), when a temperature limit of the coolant is e

Abstract: A heat exchange system for use in fluid operated equipment to provide air and working fluid heat exchanges to cool the working fluid in airstreams on a stream side of a wall. An actuator is mounted to be substantially located on a side of the wall opposite the stream side thereof having a positionable motion effector. A heat exchanger core having a plurality of passageway structures therein to enable providing the working fluid to, and removal therefrom. The heat exchanger core is mounted on the motion effector so as to be extendable and retractable thereby through the opening for selected distances into that region to be occupied by the airstreams.

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: A double pipe type heat exchanger includes an inner pipe having a first flow path defined therein and an outer pipe arranged around the inner pipe to define a second flow path between the inner pipe and the outer pipe. The inner pipe includes a spiral groove formed on an outer circumferential surface of the inner pipe to extend along a longitudinal direction of the inner pipe. The outer pipe includes a reduced diameter portion protruding inwardly so that the inner surface of the outer pipe is intermittently contacted with the outer circumferential surface of the inner pipe.