Abstract: A turbo fan engine is equipped with a main body portion that has a high-pressure turbine and a low-pressure turbine, an output portion that is provided separately from the main body portion, a gas flow channel that communicates with a space between the high-pressure turbine and the low-pressure turbine and is connected to the output portion, and a flow rate adjustment portion that is provided in the gas flow channel to adjust a flow rate of a gas flowing through the gas flow channel.

Abstract: A liquid/gas interface pressure accumulator and mechanical filter device is especially adapted for use within a propellant utilization monitoring system of a space launch vehicle. The device provides a retrofit solution for overcoming problems associated with liquid entering a pressure sensing lines and pressure noises that collectively harm the ability to accurately measure fuel and oxidizer levels. One device is attached to each fuel and oxidizer tank of the launch vehicle. Each device includes a housing and an internal sensing chamber that is used to accumulate liquid before it can enter a pressure sensing communication line connected to a pressure sensing transducer. The construction of the device also allows filtering of undesirable pressure noises due to vibration, pressure pulsations, and other vibratory events that occur during operation of the space vehicle. The device is also selectively tunable to filter out certain frequencies and frequency ranges/bands.

Abstract: Control and/or drive device for a flying body for ejecting hot gas streams of a combusted fuel combination of at least a first and second component. Device includes a first hollow chamber body structured and arranged to contain first component, a second hollow chamber body structured and arranged to contain second component, a controllable fuel valve arranged between first hollow chamber body and second hollow chamber body to control feed of first component to second hollow chamber body, and a plurality of outlets structured and arranged to eject respective hot gas streams for influencing a flight path of flying body. Second hollow chamber body is formed as a combustion chamber for combusting the at least first and second components within second hollow chamber body to generate respective hot gas streams, and plurality of outlets are connected to the second hollow chamber body.

Abstract: A booster system is disclosed, comprising a first rotor stage having a plurality of first rotor blades spaced circumferentially around a rotor hub with a longitudinal axis and having a first pitch-line radius extending from the longitudinal axis, a last rotor stage located axially aft from the first rotor stage, the last rotor stage comprising a plurality of last rotor blades spaced circumferentially around the longitudinal axis and having a second pitch-line radius extending from the longitudinal axis, and a gooseneck duct located axially aft from the last rotor stage and capable of receiving an airflow, the gooseneck duct comprising an inlet end and an exit end located at a distance axially aft from the inlet end and having at least one plasma actuator mounted in the gooseneck duct.

Abstract: An exhaust treatment device is disclosed. The exhaust treatment device includes a supply of reductant at a first pressure and an exhaust passage. The device further includes a venturi located within the exhaust passage and configured to facilitate reductant entry into the exhaust passage by reducing a pressure of exhaust flowing through the exhaust passage to a second pressure that is less than the first pressure.

Abstract: The invention relates to a diagnostic method for a reagent to be introduced into an exhaust gas region of an internal combustion engine, or a precursor of the reagent, which is required to convert at least one exhaust gas component in a catalytic converter, and to a device for performing the method. A change in the load of the internal combustion engine is first determined relative to time. If a load change threshold is exceeded, a first release signal is provided. The relative reagent material fill level in the catalytic converter is further determined. If a relative fill level threshold value is exceeded, a second release signal is provided. The reagent material slack occurring downstream of the catalytic converter is compared to a reagent material slack threshold value. If the first and second release signals are present and the reagent material slack threshold value is exceeded, the reagent material is considered to be of sufficient quality.

Abstract: An exhaust gas cleaning system for an engineering vehicle, such as a hydraulic excavator, is capable of performing manual regeneration control of a regeneration fuel injector 40 that is started only under the following conditions: a manual regeneration starting switch 39 is enabled; an engine control dial 2 commands a low-speed idle revolution speed; and a gate lock lever 22 is switched to a second position B at which generation of control pilot pressures a through f by use of remote control valves 25, 26, and 27 is disabled. Even when the manual regeneration control is being executed, if the gate lock lever 22 is switched to a first position A, the manual regeneration control immediately ends. As a result, the manual regeneration control of a filter for collecting particulate matter included in the exhaust gas and the operation of the work system do not influence each other.

Abstract: A control device for a truck dump body heating system includes a valve for controlling an exhaust gas flow to either an exhaust stack or an inlet to the dump body heating conduit. The valve may be manually controlled by the operator to select between the exhaust and heating functions. An override detects whether a diesel particulate filter regeneration is being performed, and responsive thereto, causes the valve to direct exhaust gas to the stack, preventing excessive heating of the dump body.

Abstract: An exhaust-gas system for a motor vehicle includes at least one exhaust-gas cleaning system and at least one regeneration device for the exhaust-gas cleaning system, by means of which regeneration device an oxidizable fluid in vapor form can be introduced into the exhaust-gas stream ahead of the exhaust-gas cleaning system. The regeneration device includes a housing with a chamber formed in it as well as a heating element positioned in the chamber, the housing having on its upstream side an inflow opening for exhaust gases and on its downstream side an outlet opening and being arranged in the interior of the exhaust-gas stream.

Abstract: An apparatus comprises a particulate filter substrate for an internal combustion engine, the filter substrate is coated at least in part with a washcoat, and the washcoat comprises a relatively high density material having a density of at least 3.50 gcm?3.

Abstract: An exhaust pipe for a vehicle-mounted engine. An inner pipe inserted in an outer pipe contacts, at its outer end, with the inner peripheral surface of the outer pipe at a first position, the outer pipe contacts the inner pipe at a second position different from the first position, and thus an expansion chamber is formed between the inner pipe the outer pipe. The inner pipe includes a plurality of communication holes for communicating the inside of the inner pipe and the expansion chamber, thereby forming a muffler. An exhaust gas purification catalyst is provided within the outer pipe adjacent to the expansion chamber. On the inner peripheral surface of the outer pipe, a weir for stopping condensed water is provided between the outer end of the inner pipe and the exhaust gas purification catalyst.

Abstract: The present disclosure relates to an diesel exhaust treatment device including a main body having a central longitudinal axis that extends between first and second ends of the main body. A catalyzed substrate is positioned within an interior of the main body. A side inlet is positioned at a side of the main body for directing exhaust gas into the interior of the main body. A flow distribution element is positioned within the interior of the main body at a location between the side inlet and an upstream face of the substrate. The flow distribution element extends across a direction of exhaust flow through the main body and is mounted at a side of the main body that is opposite the side inlet.

Abstract: A system is provided for admixing a reducing agent to an exhaust gas flow of an internal-combustion engine. The system includes an exhaust line and a metering device for feeding the reducing agent into the exhaust line, the metering device is arranged in or on a hollow body arranged on the exhaust line. An inner volume of the hollow body is connected in an exhaust-gas-conducting manner with the exhaust line. The reducing agent is feedable by a nozzle into the hollow body. A jacket body is provided between the hollow body and the nozzle-fed reducing agent, which jacket body surrounds the reducing agent at least in areas in the inner volume. Accordingly, a depositing of reducing agent on the metering device and on the hollow body is substantially avoided.

Abstract: The present disclosure relates to a device for mounting an injector to an exhaust pipe. The device includes an injector mounting structure having an exterior surface configured for mounting the injector. The injector mounting structure also includes an interior surface arrangement defining an interior volume and a port for allowing the injector to inject a reductant into the interior volume. The interior surface arrangement is configured to prevent swirling of exhaust within the interior volume.

Abstract: The passive energy saving device, disclosed herein, may be integrated directly into or added to the exhaust system of an internal combustion engine, to increase the system's fuel efficiency, by acting to reduce the overall backpressure of the total engine and exhaust system. It is a well known fact, accepted by those knowledgeable in the art, that a reduction of exhaust backpressure generally increases the overall fuel efficiency of an internal combustion engine. This passive device consists of a generally funnel shaped outer housing which is open at both ends, and surrounds a smaller diameter, cylindrical exhaust extension tube, which passes longitudinally, on the inside, through the center of the funnel. When airflow is introduced into this funnel, a resulting pressure drop, at the small end of the funnel reduces the backpressure on the vehicle's exhaust system. The net result of the lower exhaust pressure is the increased fuel economy of the vehicle.

Abstract: An apparatus and method for increasing energy harnessed from a liquid body flowing through a conduit includes a conduit having ascending, connecting and descending sections, valves inside the conduit, a fill unit, and at least one turbine. The valves, located in the ascending and descending portions of the conduit, regulate the flow of the liquid body through the conduit. The fill unit includes at least one of a pump and a siphon for replenishing liquid in the conduit and initiating a constant flow. An optional removably attached extension to the conduit increases the hydraulic head and increases the flow of the liquid body. The extension may include additional turbines. The turbines harness energy from the liquid body flowing with an increased flow rate through the conduit. The harnessed energy is increased by utilizing the atmospheric pressure exerted on the liquid body resulting in an increased constant flow through the conduit.

Abstract: An assembly (10) forming part of a regenerative drive system for a motor lorry. The motor lorry has a driven train that is operatively associated with the assembly (10) so as to cause operation of the assembly (10) to store energy, or alternatively to be driven by the assembly (10) by depletion of energy stored by the assembly (10). The assembly (10) includes a variable angled swash plate pump/motor (11) that is drivingly associated with the drive train and the motor lorry. The assembly (10) includes a clutch (13) that is engaged when the motor lorry is de-accelerating, to cause the pump/motor (11) to be driven.

Abstract: The present invention provides a device and a method for regulating a temperature (T) of hydraulic fluid in at least one hydraulic circuit (2) of an aircraft (1). In this case the temperature (T) of the hydraulic fluid is regulated so that it is above an adjustable minimum temperature limit value {Tmin) of approximately 20° C., for example, at all times.

Abstract: In a hybrid working machine in which the maximum engine output is set at the average power and the maximum pump input is set to be larger than the maximum engine output in a normal state, in an abnormal state in which the level of charge of a battery decreases and assistance ability of a motor function of a power machine is lost, the minimum pump flow rate is reduced to a value equal to or smaller than a standby flow rate, the standby flow rate being the minimum pump flow rate used in normal state control, and a set value of the maximum pump input is changed such that the maximum pump input is smaller than the maximum engine output.

Abstract: An exemplary hydraulic reservoir includes a reservoir tank having an interior cavity for retaining a fluid and an aperture fluidly connecting the interior cavity to an exterior region of the reservoir. A cover selectively engages the reservoir tank, and is movable between an open position, wherein the fluid path through the aperture in the reservoir tank is at least partially open, and a closed position, wherein the fluid path through the aperture is substantially closed. The hydraulic reservoir further includes a pressure relief mechanism having at least one pressure responsive fastener for releasably connecting the cover to the reservoir tank. The at least one pressure responsive fastener includes a fastener fixed for concurrent movement with one of the cover and the reservoir tank, and a biasing member operably connecting the fastener to whichever of the cover and reservoir tank is not fixed for concurrent movement with the fastener.

Abstract: There are provided a swash member and a first and second rotational members which are held on a base member through a universal joint mechanism and can rock about two axes out of three orthogonal axes including a center of the mechanism, a pump mechanism for transferring a low-pressure non-compressible fluid in a low-pressure pipe portion to a high-pressure pipe portion filled with a high-pressure non-compressible fluid being pressurized by a pressure accumulation mechanism, a control valve device which controls connection between both the pipe portions and a plurality of rocking-torque generation mechanisms which couple the base member and the swash member to each other and are driven by the fluids for generating a rocking torque to the swash member, and rocking-angle adjustment unit for changing a relative angle between the two rotational members.

Abstract: Buoyancy forces [N] and gravitational forces [N] of buoys in fluids are used as drive forces. Buoys are placed in one or more water-filled container/s. To use the buoyancy force [N], the buoys are connected to an energy storage device, herein springs. In addition, the buoys are temporarily connected to a reference system by either the container or a movable frame within the container. Upon fastening the containers to a movable system, both buoyancy and gravitational forces [N] are exerted via a short working stroke, producing effective energy. To repeat said energy supply, the movable system must resume the starting position. For this process to occur, internal and external energy may be used. In a technical application, this invention can supply electric energy via a gyrating mass, propel hydraulic or compressed air cylinders, or enable other repetitive motions (pumps.) The described system can also be used for energy storage.

Abstract: In a method and a device for utilizing heat transported by a discontinuous flow of exhaust gases (1), the discontinuous flow of exhaust gases (1) is emitted in phases (P1, P2, P3, P4, P5) with, in each case, constant output values for volume flowing (Va) and temperature (Ta) from an industrial installation, particularly an industrial furnace, wherein the discontinuous flow of exhaust gases (1) is converted into a continuous working flow (2) with adjustable, constant target values for the volume flowing (Vz) and the temperature (Tz). The continuous working flow (2), with the heat contained therein, is used for the conversion of thermal energy into useful energy.

Abstract: One embodiment is a method including interpreting a static decoupling gain set for a gas flow handling system having a plurality of inputs and a plurality of outputs. The static decoupling gain set includes gain value sets, where each gain value set decouples the plurality of inputs from the plurality of outputs at a frequency of interest and specified system operating condition of the gas flow handling system. The method further includes calculating an error term based on at least one of the inputs and a current value corresponding to one of the outputs. The method further includes providing an adjusted controller gain in response to a current system operating condition and the static decoupling gain set, and determining actuator responses based on the adjusted controller gain and the at least one error term.

Abstract: A turbocharger configuration, particularly in or for a motor vehicle, includes at least one turbocharger stage, which has a turbine and a compressor that are mechanically decoupled from each other. A turbochargeable internal combustion engine having such a turbocharger configuration, is also provided.

Abstract: In a nuclear power plant, thermal power in a second operation cycle of a nuclear reactor is uprated from thermal power in a first operation cycle preceding the second operation cycle by at least one operation cycle. A proportion of steam extracted from a steam system and introduced to a feedwater heater, which is in particular extracted from an intermediate point and an outlet of a high pressure turbine, with respect to a flow rate of main steam, is reduced in the second operation cycle from that in the first operation cycle such that the temperature of feedwater discharged from the feedwater heater is lowered by 1° C. to 40° C. in the second operation cycle.

Abstract: A combined Gasification, methanation and power island steam turbine system. The system includes a gasification portion, the methanation portion and a steam turbine portion. The Gasification portion includes the new heat recovery design and associated controls for obtaining a desired steam to dry gas ration of 1.1-2.2. The methanation portion includes first, second and third methanation reactors and associated heat recovery integrated with a high-pressure, low-pressure superheater, and HP economizers. The power Island steam turbine includes a High pressure, Intermediate pressure, low-pressure steam turbine having an input coupled to an output of the superheaters in Methanation process.

Abstract: A combustor and a combustion method for the combustor, which can suppress backfire and ensure stable combustion. The combustor comprises a mixing-chamber forming member for forming therein a mixing chamber in which air for combustion and fuel are mixed with each other, and a combustion chamber for burning a gas mixture mixed in the mixing chamber and producing combustion gases. A channel for supplying the air for combustion to the mixing chamber from the outer peripheral side of the mixing-chamber forming member is provided inside the mixing-chamber forming member. The fuel and the air are premixed in the channel, and a resulting premixed gas mixture is supplied to the mixing chamber.

Abstract: A method and apparatus for a diffusion tip for use with a fuel nozzle is described. The diffusion tip has a substantially circular body including an outer surface and an opposite inner surface. The diffusion tip body extends from a discharge end to an inlet end. The diffusion tip includes an inlet surface adjacent to the discharge end and defined within the body. A discharge surface is defined opposite the inlet surface. A plurality of diffusion apertures each extend between the discharge surface and the inlet surface, each aperture is oriented relative to the body to discharge a diffusion flow outward therefrom at an angle ? (gamma) measured in an X-Z plane between a centerline of the aperture and an X-axis extending tangentially to the outer surface, and at an angle ? (theta) measured in a Y-Z plane between the centerline of the aperture and a Y-axis extending radially outward from the centerline.

Abstract: The present application provides a manifold for use with a gas turbine. The manifold may include a fuel passage and a swozzle vane in communication with the fuel passage. The swozzle vane may include a fuel plenum in communication with one or more fuel holes and a vortex breaker positioned about the fuel holes.

Abstract: A gas turbine engine is provided and includes a fuel circuit, including multiple fuel circuit branches, a combustor having a first interior in which a first fuel supplied thereto by any one of the multiple fuel circuit branches is combustible, a turbine, a transition zone, including a second interior in which a second fuel supplied thereto by any one of the multiple fuel circuit branches, the second fuel including gas receivable by the fuel circuit from an external source, and the products of the combustion of the first fuel are combustible, the transition zone being disposed to fluidly couple the combustor and the turbine to one another, and a plurality of fuel injectors which supply the second fuel to the second interior in any one of a single axial stage, multiple axial stages, a single axial circumferential stage and multiple axial circumferential stages.

Abstract: A gas turbine engine is provided and includes a combustor having a first interior in which a first fuel is combustible, the first fuel including natural gas and/or a blend of natural gas and alternate gas receivable by a fuel circuit from an external source, a turbine, a transition zone, including a second interior in which a second fuel, the second fuel including an unblended supply of the alternate gas receivable by the fuel circuit from the external source, and the products of the combustion of the first fuel are combustible, and a plurality of fuel injectors, which are structurally supported by the transition zone and coupled to the fuel circuit, and which are configured to supply the second fuel to the second interior in any one of a single axial stage, multiple axial stages, a single axial circumferential stage and multiple axial circumferential stages.

Abstract: In one embodiment, a turbine system, may include a fuel nozzle, that includes a plurality of fuel passages and a plurality of air passages offset in a downstream direction from the fuel passages. In the embodiment, an air flow from the air passages is configured to intersect with a fuel flow from the fuel passages at an angle to induce swirl and mixing of the air flow and the fuel flow downstream of the fuel nozzle.

Abstract: A gas turbine engine is provided and includes a combustor having a first interior in which a first fuel supplied thereto is combustible, a turbine, including rotating turbine blades, into which products of at least the combustion of the first fuel are receivable to power a rotation of the turbine blades, a transition zone, including a second interior in which a second fuel supplied thereto and the products of the combustion of the first fuel are combustible, the transition zone being disposed to fluidly couple the combustor and the turbine to one another, and a plurality of fuel injectors, which are supported by the transition zone and coupled to a fuel circuit, and which are configured to supply the second fuel to the second interior in any one or more of a single axial stage, multiple axial stages, a single axial circumferential stage and multiple axial circumferential stages.

Abstract: A fuel nozzle including a swirler assembly that includes a shroud, a hub, and a plurality of vanes extending between the shroud and the hub. Each vane includes a pressure sidewall and an opposite suction sidewall coupled to the pressure sidewall at a leading edge and at a trailing edge. At least one suction side fuel injection orifice is formed adjacent to the leading edge and extends from a first fuel supply passage to the suction sidewall. A fuel injection angle is oriented with respect to the suction sidewall. The suction side fuel injection orifice is configured to discharge fuel outward from the suction sidewall. At least one pressure side fuel injection orifice extends from a second fuel supply passage to the pressure sidewall and is substantially parallel to the trailing edge. The pressure side fuel injection orifice is configured to discharge fuel tangentially from the trailing edge.

Abstract: A gas turbine combustor includes a liner having a forward end and an aft end; a flow sleeve surrounding the liner, the flow sleeve also having forward and aft ends, the aft end of the flow sleeve supporting an annular ring formed with a plurality of cooling bores and extending through the flow sleeve, at least some of the plurality of cooling bores formed at an acute angle relative to a longitudinal axis of the liner.

Abstract: A cooling arrangement for cooling a single-piece, combined combustor liner/transition piece substantially enclosed within a surrounding flow sleeve, with a cooling annulus radially between the flow sleeve and the single-piece combined combustor liner/transition piece, the cooling arrangement including a first plurality of impingement cooling holes in the flow sleeve, the plurality of impingement cooling holes having first diameters and arranged to direct cooling air onto designated areas of the single-piece, combined combustor liner/transition piece; and a second plurality of effusion cooling holes in the single-piece, combined combustor liner/transition piece having second diameters smaller than the first diameters, and located to cool by effusion other areas of the single-piece, combined combustor liner/transition piece.

Abstract: Disclosed is an apparatus for cooling a single-piece duct includes at least one metal wrapper disposed at the transition piece located outboard of the transition piece. At least one support boss is located between the metal wrapper and the transition piece. The support boss, the metal wrapper and transition piece define at least one cooling flow channel for directing flow for cooling the transition piece. A related method of cooling a single-piece duct extending between a forward end of a combustor and a first stage of a turbine includes providing a plurality of flow direction devices radially between the single-piece duct and a metal wrapper extending at least partially around the single-piece duct; flowing cooling air into a space between the single-piece duct and the metal wrapper such that the plurality of flow direction devices guide the cooling air about a surface of the single-piece duct enclosed by the metal wrapper.

Abstract: A method and apparatus are described that include a transition piece including a cooling sleeve. The cooling sleeve includes a first end and an opposite second end, the cooling sleeve is coupled to an inner wall of the transition piece, such that an annular passage is defined between the inner wall and the cooling sleeve. The first end defines an annular inlet and second end defines an annular outlet.

Abstract: A gas turbine combustor includes a fuel supplying section and a combustion tube. The fuel supplying section supplies fuel to a combustion zone inside the combustion tube. The combustion tube passes combustion gas to the turbine. The combustion tube is provided with a first region where an air passage for cooling air is formed and a second region where a steam passage for cooling steam is formed. The second region is located downstream of the first region in a direction of a mainstream flow of the combustion gas.

Abstract: In order to provide noise suppression, bumps or undulations are provided on a nozzle surface in order to vary the convergent-divergent ratio between that surface and an opposed nozzle surface. By such an approach, a circumferential variation in the shock cell pattern is created and the flow is deflected so as to enhance turbulent mixing thereby suppressing noise.

Abstract: A power and thermal management system includes an integrated power package which receives bleed air, communicates conditioned air to an environmental control air distribution system and selectively communicates electrical power with an electrical distribution system.

Abstract: A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

Abstract: A shroud suitable for use in a gas turbine engine exhibits substantially uniform thermal growth.

Abstract: An ejector for a turbine engine is described herein. The ejector may include a variable geometry motive nozzle and a variable geometry mixing tube positioned downstream of the variable geometry motive nozzle.

Abstract: In an embodiment, a method includes determining a first heating value of a low BTU fuel, determining a target fuel quality level based on a state of a turbine system, controlling a second heating value of a high BTU fuel, and injecting the high BTU fuel into the low BTU fuel to achieve the target fuel quality level.

Abstract: A burner for a gas turbine including a main burner and a pilot burner is provided. The main burner has a supporting structure, a heat shield and a holder for the heat shield, and wherein the holder is at least partially located within the supporting structure and the heat shield is at least partially located within the holder. The heat shield is fastened to the holder by a force-fit and/or a frictional connection.

Abstract: A system for delivering vapor phase fluid at an elevated pressure from a transport vessel containing liquefied or two-phase fluid is provided. The system includes: (a) a transport vessel positioned in a substantially horizontal position; (b) one or more energy delivery elements disposed on the lower portion of the transport vessel wherein the energy delivery devices include a heating means and a first insulation means, wherein the energy delivery devices are configured to the contour of the transport vessel; (c) one or more substantially rigid support devices disposed on the outer periphery of the energy delivery devices, wherein the support devices hold the energy delivery devices in thermal contact with a lower portion of the transport vessel; and (d) one or more attaching devices secure the rigid support devices onto the transport vessel and hold the energy delivery devices between the substantially rigid support device and a wall of the transport vessel.

Abstract: The present inventions provides a container for dry ice, an entrance for the dry ice and a permeable surface wherein for the duration of vaporization the permeable surface provides an exit for vapor created by the dry ice inside the container and prevents the dry ice from exiting the container. In a preferred aspect of the present invention, the entrance is configured to open and securely close. In another preferred aspect of the present invention, the container further comprises a patch to close the entrance.

Abstract: An air conditioner is provided, in which some of a plurality of outdoor heat exchangers implement a defrosting operation and others implement a heating operation. The air conditioner includes a compressor to compress refrigerant, a hot gas pipe to which a part of the refrigerant compressed in the compressor is moved, a 4-way valve to which the remaining refrigerant compressed in the compressor is moved, an indoor heat exchanger in which the refrigerant, having passed through the 4-way valve, undergoes heat exchange with indoor air, and a plurality of outdoor heat exchangers, some of which implement a heating operation as the heat-exchanged refrigerant from the indoor heat exchanger is moved therethrough while others implement a defrosting operation as the refrigerant having passed through the hot gas pipe is moved therethrough.