Abstract: Methods, devices, and systems, and devices for carrying out sorption (adsorption and absorption) for separating and/or purifying fluid mixtures are disclosed. Medical oxygen generators, dehumidifying units, sorptive heat pumps, ozone generators and Peltier devices are also disclosed. The sorption methods involve pressure swing operation of at least two sorption units. Energy from the desorbing and decompressing fluid is substantially recovered and used within the system.

Abstract: A multi-compressor heat pump system configured to provide heating and cooling over a range of ambient temperatures. The compressors can be operated independently and alone or together in series for maximum output. Heat exchangers are selectively fluidically connected to the compressors to enable refrigerant flow between the compressors and at least two heat exchangers in a manner that enables the heat pump system to be selectively operable in various modes. Preferred aspects include selectively operating the compressors based on the ratio of the evaporating and condensing pressures of the refrigerant within the heat pump system, a mixing chamber between the compressors, and a lubricant management system to prevent the accumulation of a lubricant in one of the compressors.

Abstract: District energy system comprising a pipe system, end user's locations, and an optional plant for transferring an energy transfer medium between said end user's locations and/or between said optional plant and said end user's locations, characterized by the fact that said energy transfer medium is CO2.

Abstract: An air conditioning unit for vehicles with work-doing expansion of the carbon dioxide is provided, the air conditioning unit including a combined refrigeration and heat pump circuit, wherein the air conditioning unit is switchably configured to change a flow direction of a refrigerant for switchable operation from the refrigeration circuit to the heat pump circuit. A method for operating the air conditioning unit is also provided.

Abstract: A multi-type air conditioner includes an outdoor unit, one or more indoor units communicating with the outdoor unit, and a liquid-stay preventing device heating and evaporating a liquefied refrigerant so as to prevent the liquefied refrigerant circulating between the indoor unit and the outdoor unit from being accumulated at a low pressure side including the indoor unit. Accordingly, a liquefied refrigerant is not accumulated in an indoor unit and a connection pipe, which are a low pressure side where the pressure is relatively low, but smoothly passes therethrough regardless of a height difference between the indoor unit and the outdoor unit. Therefore, the efficiency of the multi-type air conditioner is improved.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include dissimilar tube spacing configurations. The heat exchangers include multiple sets of multichannel tubes in fluid communication with each other. One set of multichannel tubes contains a plurality of tubes spaced apart at one spacing while the another set of multichannel tubes contains a plurality of tubes spaced apart at a different spacing. The different spacing between the multichannel tubes allows each set of tubes to be configured to the properties of the refrigerant flowing within the tubes.

Abstract: An engine/heat pump is shown. Most of its parts rotate around the same central axis. It comprises two doubly connected chambers. Blades in each chamber substantially rotate with the chamber and may be firmly attached to the walls of the chamber, thus forming a modified centrifugal pump with axial input and discharge. An expandable fluid is rotated outward by one of the pumps and then heat is added for an engine or removed for a heat pump as the fluid is being sent to the outer part of the second pump. The fluid travels toward the center of the second pump, thus impelling the pump in the rotation direction. Then heat is removed for an engine or added for a heat pump as the fluid leaves the second pump and travels back to the first pump near the center of rotation of both pumps. Rotation energy of the fluid is typically much larger than the circulation energy. A modified centrifugal pump with axial discharge having a casing rotating with the blades is also claimed.

Abstract: Provided is an air conditioner, particularly, an apparatus and method for controlling a super-heating degree in a heat pump system for preventing a liquid refrigerant from flowing into a compressor. The method includes: operating the heat pump system; receiving a present outdoor temperature, a pipe absorption temperature and a low pressure value of a compressor, respectively; computing a present absorption super-heating degree from a difference between the absorption temperature of the compressor and a saturated temperature at a low pressure side; and comparing an targeted absorption super-heating degree set in advance, with the computed present absorption super-heating degree according to the received outdoor temperature, and controlling the system so that the present absorption super-heating degree may follow the targeted absorption super-heating degree.

Abstract: An in-ground geothermal heating and cooling system for a building is provided. The system can include a buried ground source heat pump, a heat exchanger, and a ground loop circuit buried to a depth below the regional frost line. The system can also include a buried ground source heat pump buried inside a building to be heated. The system can also include an in-building heat exchanger disposed in a building, and an evaporative loop running from the ground source heat pump to the in-building heat exchanger. A method for installing such an in-ground geothermal heating and cooling system is also provided.

Abstract: The present invention provides an air-condition heat pump system and two-stage defrosting control method for continuous operation under an environment temperature range from 20 degree to negative 40 degree Celsius or lower. The heat pump system employs different defrosting methods under different temperature and humidity conditions. A ventilation and humidity control system is also provided for implementing the cross defrosting heat pump system within an indoor dimension.

Abstract: An air conditioner includes a refrigerant circuit that includes a heat source heat exchanger configured such that refrigerant flows in from below and flows out from above when the heat source heat exchanger functions as an evaporator of the refrigerant and a plurality of utilization heat exchangers. When the heat source heat exchanger is caused to function as an evaporator, the refrigerant discharged from a compression mechanism is bypassed to an intake side of the compression mechanism via a first bypass circuit, the heat source heat exchanger is caused to function as a condenser, and an expansion valve is closed, whereby refrigerating machine oil accumulating inside the heat source heat exchanger is returned to the intake side of the compression mechanism from a lower portion of the heat source heat exchanger via an oil returning circuit.

Abstract: A multi type air conditioner comprises: an outdoor unit including an outdoor heat exchanger heat-exchanged with the outdoor air, a compressor compressing a refrigerant, and a first four-way valve and a second four-way valve switching a refrigerant flow path; indoor units performing at least one of cooling operation and heating operation; and a distributor including a low pressure pipe connected between the first four-way valve and each of the indoor units, a high pressure pipe connected between the second four-way valve and each of the indoor units, and a refrigerant pipe connected between the outer heat-exchanger and each of the indoor units. Accordingly, flow resistance of a refrigerant is reduced in heating operation, thereby improving heating performance and heating efficiency, and the amount of refrigerant accumulated within a high pressure pipe is minimized in cooling operation, thereby improving cooling performance and cooling efficiency.

Abstract: An air conditioning system includes an air-cooling unit and an air-heating unit. On a first path in the cooling-unit, provided are a compressor for first refrigerant, a condenser for the first refrigerant, an expansion unit for the first refrigerant, and an evaporator to cool air. On a second path in the air-heating unit, provided are an air-conditioning radiator for second refrigerant, and a first valve for the second refrigerant (whether or not into the air-conditioning radiator) On a third path in the air-heating unit, provided are a driving-system heating element to heat third refrigerant, an internal heat exchanger to heat the third refrigerant, a heater core to heat air, a driving-system radiator for the third refrigerant, and a second valve for the third refrigerant (whether or not into the driving-system radiator). The air passing through the evaporator or the heater core is selectably sent into a vehicle compartment.

Abstract: Heat engines move heat from a source to a sink. In a subset of heat engines, called heat pumps, the temperature of the source is below that of the sink. A subset of heat pumps, called working-fluid heat pumps, accomplishes the heat-pumping function by varying the temperature of a working fluid over a range that includes the temperatures of both the source and the sink. A subset of working fluid heat pumps, called Bernoulli heat pumps, accomplish this temperature variation of the working fluid by means of Bernoulli conversion of random molecular motion into directed motion (flow). This invention is a Bernoulli heat pump in which Bernoulli conversion is accomplished using a rotating disk, similar to those used in computers for data storage. Most working fluid heat pumps used for cooling and heating accomplish the temperature variation by compression of the working fluid. In contrast to compression, Bernoulli conversion consumes no energy.

Abstract: A heat pump device in which a temperature difference is established between two heat exchangers by inducing cyclical expansion and compression pulses in a working fluid vapour or gas which passes through an adsorbent porous solid located between the heat exchangers.

Abstract: A method for transporting a fluid comprising a clathrate forming gas through a transportation system including a pipeline. The method involves subjecting the fluid to clathrate forming temperature and pressure conditions and introducing sufficient of a clathrate forming host to convert substantially all of the gas to clathrate and to form a flowable slurry. The flowable slurry is then conveyed through a pipeline to a destination. An alternative method involves transporting the fluid by means of a ring pipeline containing a carrier fluid, which includes clathrate inhibitors. Also provided is a heat pump whose working fluid is a clathrate forming composition.

Abstract: In a heat pump system including a water purifier and an evaporator for evaporating feed-water to produce steam, water used for spray cooling is effectively used and productivity of purified water used for the spray cooling is increased. Discharged water from the water purifier is supplied to the evaporator when water used for spray cooling is produced by use of the water purifier. Otherwise, drain of the evaporator having higher temperature is supplied to the water purifier by using such a fact that in a reverse osmosis membrane type water purifier, the higher the temperature of feed-water is, the higher the purified water productivity becomes.

Abstract: A heat pump system operates in heating and cooling modes. The heat pump is provided with both a reheat function and economizer circuit. The economizer circuit provides augmented performance to the heat pump, while the reheat coil allows enhanced control over temperature and humidity of the air supplied to the conditioned space. A bypass line around an outdoor heat exchanger is also provided to achieve additional flexibility of control for a sensible heat ratio. Selective operation of the abovementioned components and subsystems allows precise control over system operation parameters and hence satisfaction of a wide spectrum of sensible and latent load demands and improved reliability.

Abstract: There is a working fluid for a heating and cooling. The fluid is a blend of about 1% to about 98% by mass 1,1,1,3,3-pentafluoropane, about 1% to about 98% by mass 1,1,1,2,3,3-hexafluoropropane, and about 1% to about 98% by mass 1,1,1,2-tetrafluoroethane. The 1,1,1,3,3-pentafluoropane, 1,1,1,2,3,3-hexafluoropropane, and 1,1,1,2-tetrafluoroethane are about 90% or more by mass of the blend. There are also an apparatus that uses the blend and methods for heating and cooling using the blend.

Abstract: A method includes operating a compressor of a heat pump system and is selectively providing vapor to a vapor injection port of the compressor via a vapor injection line and vapor injection valve. The method further includes determining a frost condition of a first and second heat exchanger of the heat pump system and closing a vapor injection valve to prevent fluid flow into the compressor at the vapor injection port. A direction of refrigerant flow is reversed to direct vaporized refrigerant to the one of said first and second heat exchangers experiencing the frost condition. The vapor injection valve is opened after a first predetermined time period following reversal of the refrigerant flow. The method further includes closing the vapor injection valve and reversing a direction of refrigerant flow within the heat pump system once the vapor injection valve is closed for a second predetermined time period.

Abstract: An adsorption heat pump is provided in which water vapor can be efficiently adsorbed and desorbed using a heat source having a lower temperature than ones heretofore in use because the pump employs an adsorbent which has a large difference in water adsorption amount in adsorption/desorption and can be regenerated (release the adsorbate) at a low temperature. The invention provides an adsorption heat pump which comprises an adsorbate, an adsorption/desorption part having an adsorbent for adsorbate adsorption/desorption, a vaporization part for adsorbate vaporization which has been connected to the adsorption/desorption part, and a condensation part for adsorbate condensation which has been connected to the adsorption/desorption part, wherein the adsorbent, when examined at 25° C., gives a water vapor adsorption isotherm which, in the relative vapor pressure range of from 0.05 to 0.30, has a relative vapor pressure region in which a change in relative vapor pressure of 0.

Abstract: To provide a working fluid for a heat cycle, which is nonflammable, little influential to the environment and excellent in heat cycle characteristics, and a Rankine cycle system, a heat pump cycle system and a refrigeration cycle system, which have high capacity and efficiency. A working fluid for a heat cycle containing HFE-347, and a Rankine cycle system using the working fluid for a heat cycle of the present invention, a heat pump cycle system using the working fluid for a heat cycle of the present invention and a refrigeration cycle system using the working fluid for a heat cycle of the present invention.

Abstract: A heat-pump system may include a compressor, an outdoor heat exchanger including an outdoor coil, an indoor heat exchanger including an indoor coil, and a sensor assembly including a first sensor disposed in the outdoor coil, a second sensor disposed in the indoor coil, and a third sensor disposed between the outdoor heat exchanger and the indoor heat exchanger. A controller may receive data from the first sensor, the second sensor, and the third sensor and may determine a first system operating parameter when the heat-pump system is operating in a cooling mode and a second system operating parameter when the heat-pump system is operating in a heating mode.

Abstract: A refrigerant cycle unit having a side heat exchanger for dehumidifying a space, and a heating mode for delivering a refrigerant from a compressor into an internal gas cooler. The refrigerant cycle unit further includes a cooling mode delivering the refrigerant from the compressor into the external heat exchanger, and after being decompressed by the compressor flowing the refrigerant into an evaporator and into the internal gas cooler. The refrigerant flows into the evaporator, and the decompressed refrigerant flows into the external heat exchanger and the two refrigerants are discharged from the evaporator and the external heat exchanger, respectively, and are united together and returned to the compressor.

Abstract: The improvement system of energy efficiency for the refrigeration cycle is comprised of: an auxiliary heat exchanger unit for heat-exchanging between refrigerant liquid having high pressure and refrigerant vapor having low pressure; and a cabinet which houses a pressure support value placed at an inlet of an inner pipe of the auxiliary heat exchanger unit, and a pressure of the refrigerant liquid having high pressure condensed at the outdoor heat exchanger is decreased by the pressure support value, and a condensed pressure of the outdoor heat exchanger is maintained. The system can be used to accompany with the ordinary air cooler and heat pump etc., and a conventional refrigerator can be utilized for both heating and cooling like the heat pump, thus leading to an increase of coefficient of performance and a decrease of consumption of electric power.

Abstract: A reversible mode heating and cooling system for an interior space of a vehicle having an Auxiliary Power Unit (APU) employs a heat pump arrangement, wherein a refrigerant compressor is driven by APU's diesel engine through pulley and belt arrangement. An air duct is provided to communicate engine exhaust air to an external heat exchanger during a heating mode. Openings and dampers are provided in the air duct to direct engine exhaust air flow to atmosphere and introduce ambient air into the external heat exchanger during cooling mode. Exhausted air from the external heat exchanger may be re-circulated back to the air inlet side of the engine. Provisions are also provided for operating the refrigerant compressor from the electrical power grid.

Abstract: A second-refrigerant pump driving type air conditioner, including an indoor unit having an indoor heat exchanger that circulates a refrigerant containing no oil, a first circulator including a compressor that compresses and discharges a refrigerant containing oil, a first outdoor heat exchanger, a second outdoor heat exchanger, and an outdoor expander, and a second circulator including an intermediate heat exchanger connected to the indoor heat exchanger that circulates the refrigerant containing no oil and heat-exchanges the refrigerant of the first outdoor heat exchanger, a receiver, and a pump. A restriction of a length and a diameter of a connection pipe for connecting an outdoor unit and the indoor unit is decreased, and an oil shortage of the compressor is prevented.

Abstract: A refrigerant reverse cycle balancing receiver includes an outer housing with a volume formed therein. A refrigerant pipeline extends through the volume for connection with a refrigerant line of a refrigeration system. The refrigerant pipeline is provided with a refrigerant relief port within the outer housing for allowing excess refrigerant to back up and fill the volume of the receiver when required in use.

Abstract: The invention relates to a building heating system which includes an insulated foundation (9) beneath the lowermost (12) of the building. According to the invention, the system comprises at least one heat pump (1, 2) that includes a heat absorbing side (2) located in the foundation space (9). The system also includes means (23) for distributing air from the foundation space (9) to spaces situated above the floor (12). The system also includes means (7) for delivering external air to the foundation space (9). The invention also relates to a method of heating a building.

Abstract: An air conditioning system to treat a latent heat load and a sensible heat load in a room includes a plurality of utilization units, a heat source unit, and connection pipes that connect between the units. The utilization units include adsorbent heat exchangers provided with an adsorbent on the surface of each. The utilization units are configured to alternate between an adsorption process and a regeneration process. The heat source unit includes a compression mechanism and an accumulator.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include dissimilar tube spacing configurations. The heat exchangers include multiple sets of multichannel tubes in fluid communication with each other. One set of multichannel tubes contains a plurality of tubes spaced apart at one spacing while the another set of multichannel tubes contains a plurality of tubes spaced apart at a different spacing. The different spacing between the multichannel tubes allows each set of tubes to be configured to the properties of the refrigerant flowing within the tubes.

Abstract: A heat exchanging system facilitating the transfer of heat energy between (i) a heat energy exchanging subsystem employed in the system, and (ii) the ambient environment. One or more coaxial-flow heat exchanging structures are installed in the ambient environment, for facilitating the transfer of heat energy in a heat conducting stream between (i) the heat energy exchanging subsystem and (ii) the ambient environment. Each said coaxial-flow heat exchanging structure includes an inner tube section having an outer wall surface extending between the proximal and distal ends, and a thermally conductive outer tube section, disposed coaxially around the inner tube section, and having an inner wall surface extending between the proximal and distal ends. An outer flow channel is provided between the outer wall surface of the inner tube section and the inner wall surface of the outer tube section.

Abstract: A vapor-compression air conditioning system comprising a blower positioned in a return air flow path from a conditioned space, a reheat heat exchanger positioned in the return air flow path and downstream from the blower, a system reversing valve fluidly coupled to the reheat heat exchanger, and a refrigerant flow sequencer interposed the system reversing valve and the reheat heat exchanger. A method of manufacturing an air conditioning system is also provided.

Abstract: The present invention provides a heat source unit capable of being used in either an air conditioner for switchable cooling and heating operation or an air conditioner for simultaneous cooling and heating operation. An air conditioner principally includes one heat source unit, a plurality of utilization units, and a connecting unit provided for each utilization unit. The heat source unit uses water as the heat source, and principally includes a compressing means, a main heat exchanger, a first switching means, a main refrigerant switching means, an auxiliary heat exchanger connected in parallel with the main heat exchanger, a second switching means, an auxiliary refrigerant switching means, and a liquid receiver. The auxiliary heat exchanger is capable of switching between functioning as an evaporator and a condenser, by the second switching means.

Abstract: An electromagnetic signal transmission/reception tower and accompanying base station housing sensitive electronic equipment within an environment that is thermally controlled by a system employing a plurality of coaxial-flow heat exchanging structures installed in a plurality of well bores, using thermally conductive material. Each coaxial-flow heat exchanging structure includes: a helically-extending turbulence generator arranged along the outer flow channel formed between its inner and outer tube sections, so as to create turbulence along the flow of heat exchanging fluid flowing along the outer flow channel, and thereby increasing the heat transfer through the walls of the outer tube section to the Earth.

Abstract: Disclosed herein is a heat pump. The heat pump comprises a compressor, indoor and outdoor heat exchangers for condensing or evaporating refrigerant compressed by the compressor according to cooling or heating operation mode, a four-way valve for guiding the flow of the compressed refrigerant to the indoor heat exchanger or the outdoor heat exchanger according to the operation mode, an expansion valve for selectively decreasing the pressure of liquid refrigerant according to the operation mode, a check valve selectively opened or closed according to the operation mode for guiding the flow of the liquid refrigerant to the expansion valve, an accumulator for preventing the liquid refrigerant from entering into the inlet of the compressor, connection pipes, and a heat exchange part for performing heat exchange between the connection pipe connected to the inlet of the accumulator and the connection pipe connected to the indoor heat exchanger.

Abstract: A combined heating/cooling system and method is provided wherein an absorption tank (20) houses a refrigerant and absorbant mixture composition. A boiler (50) heats the high pressure mixture composition and vaporizes the refrigerant. Heated absorbant is passed back through a heat exchanger (40) to be delivered back into absorption tank (20) and the vaporized refrigerant is directed to a closed-loop thermal exchange system for selectively heating and cooling ambient air. The refrigerant and absorbant mixture composition is preferably Genosorb® 1843 and HCFC-124.

Abstract: An air conditioning system comprises a first tank connected to an outlet side refrigerant line of an indoor unit, a second tank disposed to be lower than the first tank, middle tank installed between the first tank and the second tank, a heat source cycle for depressurizing and cooling the first refrigerant inside the first tank by circulating a second refrigerant and heating the first refrigerant of the second tank, a middle tank cooling unit for feed back connected to an inlet side refrigerant line of the second tank among refrigerant lines of the heat source cycle, a middle tank heating unit for feed back connected to a refrigerant line between the first tank and the second tank among refrigerant lines of the heat source cycle, and a controller for selectively circulating the second refrigerant of the heat source cycle to the middle tank cooling unit for feed back or the middle tank heating unit for feed back.

Abstract: A heat pump water heater system including a water storage tank and a heat exchange system. The heat exchange system includes a heat absorber positioned below the water storage tank and a heat rejecter in fluid communication with the heat absorber and positioned within the water storage tank. The heat absorber is configured to transfer heat to fluid in the heat exchange system, and the heat rejecter is configured to transfer heat from fluid in the heat exchange system to the water in the water storage tank.

Abstract: A gas heat pump system powered by natural gas, propane or similar gaseous fuel is disclosed. The system uses heat recovery and heat addition to manage efficient heating and cooling cycles. In a cooling cycle excess heat is vented to the atmosphere while in a heating cycle, excess heat is used to heat a subject structure and to prevent frost from forming on outdoor heat exchangers. A control system monitors the system's operation and corrects abnormal operational conditions or shuts down the system until the system can be manually inspected. The costs of system operation are less than electric systems because of the efficiencies and use of natural gas or propane.

Abstract: Heat pumps move heat from a source to a warmer sink, with Bernoulli heat pumps accomplishing this movement by reducing the temperature in a portion of the generally-warmer heat-sink flow. Heat flows spontaneously from the generally cooler heat-source flow into the locally cold portion of the heat-sink flow, which is the neck of a Venturi. The temperature reduction results from the Bernoulli conversion of random gas-particle motion (temperature and pressure) into directed motion (flow). This invention is a Bernoulli heat pump in which the heat transfer into the Venturi neck exploits unusual thermodynamic transport properties of rare-gases. Rare gases, especially mixtures of them, possess unusually small Prandtl numbers and thereby facilitate the diffusion of random particle motion (heat) relative to the diffusion of directed particle motion (viscosity), viscous friction being responsible for most of the power consumed by a Bernoulli heat pump.

Abstract: Disclosed related to a co-generation comprising a heat exchanger heating water; a heat transfer path connected with the water heat exchanger to transfer heat; a hot water storage tank connected with the water heat exchanger and the water circulation path; a hot water storage water supply apparatus supplying water in the hot water storage tank to the water circulation path; a water supply path connected with the water circulation path; a water supply apparatus supplying water to the water supply path; and a hot water supply heat exchanger bypassing apparatus and bypassing the water supplied to the water circulation path from the hot water storage tank through the hot water supply heat exchanger.

Abstract: A flash water heater using a heat pump includes a heat exchanger in which a refrigerant flow path exchanges heat with a water flow path. Tap water is led directly to the water flow path, and hot water supplied from the water flow path is used. The water heater includes at least one of the following elements: 1) a load setter for setting a heating amount in the heat exchanger, and a heating controller for regulating a heating amount in response to an amount set by the load setter; 2) a heater for heating water flowing through the water flow path in the heat exchanger and water flowing the path before and after the heat exchanger; 3) plural compressors; and 4) plural heat-pump cycles. The water heater is excellent in start-up of hot water temperature when the hot water supply starts, controllability, and efficiency.

Abstract: A heat pump liquid heater for heating a liquid comprising: a heat pump; a liquid tank in heat communication with the heat pump, wherein the liquid tank comprises the liquid; and at least one metal condenser tube immersed into the liquid, wherein the metal condenser tube forms at least one coil. The metal condenser tube has a flattened double-tube configuration and a cross-section defined by concentric ovals such that at least a portion of the concentric ovals is in contact with one another thereby minimizing space between the flattened double-tubes. The heat pump comprises a tube-in-tube heat exchanger and a compressor, wherein the tube-in-tube heat exchanger recovers heat from refrigerant returning from the liquid tank and transfers the recovered heat to refrigerant going to the compressor thereby superheating the refrigerant.

Abstract: In a refrigerant circuit (20), a refrigerator circuit (110) and a freezing circuit (30) are connected in parallel to an outdoor circuit (40). In the freezing circuit (30), a freezer circuit (130) and a booster circuit (140) are connected in series. A booster compressor (141) and a four-way switch valve (142) are provided in the booster circuit (140). During the time when a freezer heat exchanger (131) performs cooling operation for cooling the inside air, refrigerant evaporated in the freezer heat exchanger (131) is compressed in the booster compressor (141), and then, is sucked into a variable capacitance compressor (41). On the other hand, during defrosting of the freezer heat exchanger (131), the refrigerant evaporated in a refrigerator heat exchanger (111) is compressed in the booster compressor (141), and then, is supplied to the freezer heat exchanger (131).

Abstract: A refrigeration system of air conditioning apparatuses with a bypass line between the inlet and outlet of a compressor. The refrigeration system (1) has an expansion unit (10) to execute adiabatic expansion of refrigerant, an indoor unit (20) with a heat exchanger, a compressor (30) to execute adiabatic compression of the refrigerant, and an outdoor unit (40) with a heat exchanger, and is operated to cool or heat air within a space to a desired level by using the phase change of the refrigerant. The refrigeration system also has a bypass line (99) between the inlet and outlet of the compressor (30) to bypass at least a part of the output refrigerant from the outlet to the inlet of the compressor when the pressure of the output refrigerant is lower than a reference level or the temperature of the air outside the compressor is lower than a reference level.

Abstract: In order to provide a thermo-siphon chiller refrigerator for use in cold districts which performs natural refrigerant-circulation refrigerating cycle and also can perform a forced refrigerant-circulation refrigerating cycle when outside air temperature is high by using an indoor heat exchanger, an outdoor heat exchanger, and a compressor, and combining them with refrigerant piping, the thermo-siphon chiller refrigerator for use in cold districts of the invention has a compressor (10) additionally installed to a natural refrigerant-circulation refrigerating system comprising an outdoor heat exchanger (12), an indoor heat exchanger (11) located at a position lower than that of the outer heat exchanger (12), and an expansion valve (18). When the refrigerating capacity of the natural refrigerant-circulation refrigerating system is not sufficient, the additional compressor (10) is operated to perform a forced refrigerant-circulation cycle i.e. a vapor compression refrigerating cycle.

Abstract: In a multi-circuit heat pump system least one of the circuits has a reheat function. Various reheat concepts may be independently utilized for each circuit to reheat and dehumidify air. Moreover, the ability to bypass refrigerant around the outdoor heat exchanger may also be provided. Communication means between the circuits may be present to re-optimize the refrigerant charge and to provide better control over system operational parameters. The above mentioned control functions and design features assure system flexibility in satisfying a wide spectrum of market requirements and potential applications by operation in a variety of cooling, heating and dehumidification regimes and a combination of thereof.

Abstract: A refrigerant heat pump system is operable in both heating and cooling modes. A reheat circuit is integrated into the system schematic to provide improved control over temperature and humidity and to cover a wide spectrum of sensible and latent capacity demands.

Abstract: A refrigerant heat pump system is operable in both heating and cooling modes. A reheat circuit is integrated into the system schematic to provide improved control over temperature and humidity and to cover a wide spectrum of sensible and latent capacity demands. In the heating mode, the reheat coil is utilized to act as a portion of the enlarged indoor heat exchanger (a condenser in this case), in order to enhance system efficiency without the capacity loss. In some cases, where the designer can choose between the efficiency and capacity augmentation, selective operation of the reheat coil may offer an additional step of capacity modulation, in the heating mode. System reliability is improved through a reduction of start/stop cycles. Although various reheat coil arrangements in relation to the indoor and outdoor heat exchangers are offered and reheat concepts are considered, the benefits of the invention are independent from and transparent to such system design features.