Showing papers on "Thermal expansion valve published in 2004"

Heat pump clothes dryer

Abstract: A drying apparatus for drying articles such as clothing is provided. The drying apparatus includes a chamber for containing articles to be dried and a system for supplying heated dry air at a first temperature to the chamber. The air supplying system comprises an air flow pathway having an evaporator for removing moisture from air exiting the chamber and for decreasing the temperature of the air to below dew point temperature. The air supply system further has a condenser for increasing the temperature of the air exiting the evaporator to the first temperature. The drying apparatus further has a heat pump system having a refrigerant loop which includes a compressor, the condenser, a TEV valve, and the evaporator.

Experimental investigation on the performance of the refrigeration cycle using a two-phase ejector as an expansion device

Abstract: In the present study, new experimental data on the performance of a never before seen two-phase ejector refrigeration cycle (TPERC) is presented. In this cycle, a two-phase ejector is used as an expansion device. The TPERC enables the evaporator to operate as in a liquid-recirculation system. The results are compared with those of the conventional refrigeration cycle (CRC). The effects of external parameters, i.e., heat sink and heat source temperatures on the system performance are discussed. The results show that the coefficient of performance of the TPERC is higher than that of the CRC over the whole range of experimental conditions. This is due to a higher refrigerant-side heat transfer coefficient in the evaporator, resulting from the higher refrigerant mass flow rate passing through the evaporator. However, the increase becomes relatively smaller as the heat sink temperature increases.

Loss of refrigerant charge and expansion valve malfunction detection

Abstract: An actual superheat value in a refrigerant system is compared to an expected superheat level. If the actual superheat valve exceeds a certain predetermined value, this is an indication of refrigerant charge loss or a malfunctioning expansion device. In one example, the superheat valve is determined by comparing a difference between a saturated vapor temperature and an actual operating vapor temperature. The superheat determination can be made either at evaporator exit, economizer heat exchange exit or near the compressor discharge port.

Dual compressor HVAC system

Abstract: The present invention concerns an automotive HVAC system for use in a vehicle having a vehicle body that includes an engine and a battery. The HVAC system has a predetermined design cooling capacity and includes a condenser and one of an orifice tube and an expansion valve in fluid communication with the condenser. A first compressor is adapted to be mechanically driven by the engine and is in fluid communication from the evaporator and in fluid communication to the condenser. A second compressor is electrically connected to and driven by the battery bank and is in fluid communication from the evaporator and in fluid communication to the condenser. Each of the compressors is selectively operable to compress refrigerant in the HVAC system during operation of the HVAC system.

Air conditioner for vehicle

Abstract: PROBLEM TO BE SOLVED: To achieve an integral, efficient operation with a traveling engine in an air conditioner for vehicles for air-conditioning the inside of a compartment. SOLUTION: In the air conditioner for vehicles, a refrigerant circuit comprises a rotary compressor 10; a gas cooler 110; an expansion valve 112; an evaporator 114, and the like, to air-condition the inside of a compartment by the evaporator 114. The air conditioner comprises an oil/refrigerant heat exchanger 118 for exchanging heat between oil for the traveling engine of vehicles and a refrigerant at the high-pressure side of the refrigerant circuit; and solenoid valves 113, 117 for controlling the circulation of refrigerant to the oil/refrigerant heat exchanger 118. By allowing the refrigerant to flow to the oil/refrigerant heat exchanger 118 when the temperature of the oil for traveling engines is low by the solenoid valves 113, 117, oil can be readily heated by the refrigerant at the high-pressure side of the refrigerant circuit when the oil for traveling engines is still cool when a vehicle is started. COPYRIGHT: (C)2004,JPO&NCIPI

Integrated circuit cooling apparatus and method

Abstract: In various embodiments, heat from a computer component may be absorbed into a medium, moved to a remote heat dispersal unit and dissipated into the surrounding air. In some embodiments, the heat dispersal unit may include a heat sink. In some embodiments, the medium may include a liquid metal. In various embodiments, a vapor compression system may include an evaporator, a compressor, a condenser, and an expansion valve. In some embodiments a separate heat pipe may be placed between the computer component and the evaporator. In various embodiments, a thermo conductive plate may be used to thermally couple the heat pipe to various components including the computer component, evaporator, condenser, and/or heat sink. In some embodiments, a thermo electric module (TEM) may be coupled to various parts of the system.

Flow distribution issues in parallel flow heat exchangers

Abstract: This paper discusses issues of single- and two-phase flow distribution in manifolds of heat exchangers: flow in the tube after the expansion valve, flow regimes in the manifold, and pressure drop in the heat exchanger channels. A few typical options for reasonable distribution are shown.

Apparatus and method for controlling the temperature of an electronic device

Abstract: An apparatus for controlling the temperature of an electronic device. The apparatus comprises a refrigeration system including a compressor and a multi-pass heat exchanger. The refrigeration system is operative to circulate a refrigerant fluid through a fluid flow loop such that the refrigerant fluid will change between gaseous and liquid states to alternately absorb and release thermal energy. The refrigerant fluid is pre-cooled in the heat exchanger by a pre-cooling refrigerant stream. A thermal head is connected into the fluid flow loop and has a temperature controlled surface.

Control method for operating a refrigeration system

Abstract: A method of controlling a heating cycle of a refrigeration system is provided that includes a refrigerant circuit. The refrigerant circuit includes a compressor having a suction port and an outlet having a discharge port with a hot gas compressor discharge line, a condenser for condensing the refrigerant, an evaporator for evaporating the refrigerant and an expansion valve. The method includes using refrigerant from the hot gas compressor discharge line to heat the evaporator during a heating cycle, detecting periodically a discharge superheat of the refrigerant leaving the outlet of the compressor, producing a control signal representing a difference between the detected discharge superheat and a minimum discharge superheat setpoint, adjusting the flow rate of the refrigerant to the suction port of the compressor according to the control signal so as to maintain the discharge superheat of the refrigerant at the outlet of the compressor substantially at the minimum discharge superheat setpoint.

Vapor injection system

Abstract: A heat pump includes a first and second heat exchanger, a scroll compressor and a flash tank in fluid communication. The flash tank includes an inlet fluidly coupled to the heat exchangers to receive liquid refrigerant. Furthermore, the flash tank includes a first outlet fluidly coupled to the first and second heat exchangers and a second outlet fluidly coupled to the scroll compressor. The first outlet is operable to deliver sub-cooled-liquid refrigerant to the heat exchangers while the second outlet is operable to deliver vaporized refrigerant to the scroll compressor. An expansion valve is further provided and is operable to selectively open and close the inlet by a float device. The float device is operable to control an amount of liquid refrigerant disposed within the flash tank by regulating an amount of liquid refrigerant entering the flash tank via the inlet.

Heat dissipating device with enhanced boiling/condensation structure

Abstract: A heat dissipating device. The heat dissipating device comprises a receptor plate to be placed over a device that generates heat, an evaporator coupling to the receptor plate, a condenser column placed in fluid communication with the evaporator, and a set of condenser extension surfaces extending from the condenser. The evaporator includes a modulated porous layer and stores liquid. The condenser column includes a non-wetting surface. The condenser extension surface facilitates heat dissipation.

Air conditioner comprising heat exchanger and means for switching cooling cycle

Abstract: The present invention relates to an air conditioner capable of performing heat exchange of refrigerant and cooling and heating operations. According to the invention, a dual-tube heat exchanger is disposed at the entrance of a compressor and a means for switching a cooling cycle is installed between an outdoor heat exchanger including a condenser and an indoor heat exchanger including an evaporator so that in an air conditioning mode, heat change between mid-temperature, high-pressure liquid refrigerant at the exit of the condenser and low-temperature, low-pressure superheated refrigerant at the exit of the evaporator is performed more effectively and as a result of this, super heating of the liquid refrigerant at the exit of the condenser is increased, refrigerant flow characteristics of an expansion unit are improved, and enthalpy at the entrance side of the evaporator is reduced, causing a greater enthalpy difference at the entrance and exit of the evaporator and improving air conditioning capacity overall. Moreover, the heat exchanger of the present invention has a dual tube structure and uses a counter flow or parallel flow for performing heat exchange. In the dual tube structure, a tube and a core of the heat exchanger form a line or surface contact and heating capacity is therefore enhanced.

Air conditioner for vehicle capable of recovering vehicle deceleration energy

Abstract: During the period of deceleration of a vehicle, an air conditioning control unit modifies a target cooling temperature (TEO) of an evaporator to a temperature lower than that before the deceleration by γ ° C in order to store cold in the evaporator (step S 130 ) When the vehicle comes to rest, the air conditioning control unit sets an upwardly-modified target temperature TEOK, which is a temperature modified toward more or less higher temperatures from the target cooling temperature TEO, and brings a compressor to rest and keeps the resting state of the compressor until a detected temperature TE of an evaporator discharge temperature sensor exceeds TEOK (step S 180 ) Therefore, it is possible to effectively utilize the cold heat stored in the evaporator 6 during the period of deceleration of the vehicle with a good feeling of passengers being maintained while the vehicle is at rest

Horizontal rotary compressor in a bus air conditioner

Abstract: A bus air conditioning system with at least one air conditioning module installed on a bus roof. The air conditioning system having a pair of supply air openings for conducting the flow of conditioned air downwardly near the outer side of the roof and a return air opening whose position may vary substantially in the lateral direction from a longitudinal central axis of the bus for any given installation. The air conditioning system including a refrigeration circuit for circulating refrigerant serially through a compressor, a condenser coil, an expansion valve and an evaporator coil. The air conditioning system further including an evaporator section including an evaporator blower for causing return air to flow from said return air opening, into a return air compartment of the evaporator section, through the evaporator coil and then to the supply air opening. The air conditioning system further includes a condenser fan for causing outside air to flow over the condenser coil and then to be discharged outside. Where the compressor is a horizontal compressor with a longitudinal axis. The compressor is mounted proximate to the roof of the bus and external to the passenger compartment of the bus and the compressor oriented such that the longitudinal axis of the compressor is substantially perpendicular to the longitudinal axis of the bus.

Compressor with unloader valve between economizer line and evaporator inlet

Abstract: A compressor has an economizer injection line communicating into the compressor compression chambers. An unloader valve selectively communicates the economizer injection line back to a point upstream of the evaporator. When the compressor is run in unloaded mode, partially compressed refrigerant is thus returned to a point upstream of the evaporator. In unloaded mobile, this results in a higher refrigerant mass flow through the evaporator, as compared to prior art when the bypassed refrigerant was returned downstream of the evaporator. This increases system efficiency by more effectively returning oil which otherwise might be left in the evaporator back to the compressor. Also, the amount of refrigerant superheat entering the compressor in unloaded operation is reduced as compared to the prior art compressor systems, wherein the bypassed refrigerant is returned directly to the compressor suction line. Reduced refrigerant superheat increases system efficiency, improves motor performance and reduces compressor discharge temperature.

Loop type thermo syphone, heat radiation system, heat exchange system, and stirling cooling chamber

Abstract: A natural circulation circuit includes an evaporator surrounding a heat radiating portion of a Stirling refrigerating machine to absorb heat of the heat radiating portion through evaporation of a coolant, a condenser arranged to be higher than the evaporator to condense the coolant having gas phase, a conduit guiding the coolant from the evaporator to the condenser, and a return pipe returning the liquefied coolant from the condenser to the evaporator. In the evaporator a distance between an opening of the return pipe and an inner circumferential surface of the evaporator is smaller than that between an opening of the conduit and the inner circumferential surface.

Heating And Defrosting Methods And Apparatus

Abstract: A heat pump includes a compressor 1 , a condenser 2 , an expansion valve 3 , an evaporator 4 and a heat exchanger 6 a . The heat exchanger 6 a is located immediately downstream of the expansion valve 3 and upstream of the evaporator 4 . A controller 8 monitors one or more variables which predict may be about to occur by means of a sensor 11 . When this is predicted the heat exchanger 6 a will receive hot refrigerant through line 17 from the high pressure side of the compressor 1 so as to heat the refrigerant entering the evaporator 4 until ice formation is no longer likely. In an alternative embodiment, the heat exchanger may utilise an electric element to heat the refrigerant before it enters the evaporator. The heat exchanger 6 a can preferably utilise a helically corrugated tube in order to enhance its heat exchange characteristics.

Refrigerating system for steam compression refrigerator

Abstract: PROBLEM TO BE SOLVED: To provide a refrigerating system eliminating an expansion valve and omitting measuring instruments and control equipment required for high precision control to reduce the occurrence frequency of failures or the like. SOLUTION: The expansion valve is eliminated, and an evaporator 16, a compressor 20, a condenser 18, a cooling tower 24 and load side connection piping 21 are connected as a sealed system. A vacuum state is created inside to operate the compressor 20. Steam in the evaporator 16 thereby evaporates to lower the internal temperature of the evaporator 16. After compressing the steam by the compressor 20, the steam having a high temperature is led to the condenser 18 and condensed in the condenser 18 by cooling water from the cooling tower 24 to become water again. The cooling water raised in temperature by the condensation of high temperature steam is fed to the cooling tower 24 or the like, and the heat is radiated to the outside by the cooling tower 24. Condensed water in the condenser 18 is returned to the evaporator 16 through the connection piping 17 connecting the condenser 18 and the evaporator 16, to maintain the water level difference corresponding to the pressure difference between both containers. COPYRIGHT: (C)2006,JPO&NCIPI

Refrigeration unit having a linear compressor

Abstract: A refrigeration merchandiser including at least one surface at least partially defining an environmental space adapted to accommodate a commodity. The merchandiser includes a linear compressor, a condenser, an expansion device, and an evaporator. The linear compressor, which can be a free-piston linear compressor having dual-opposing pistons, the condenser, the expansion valve and the evaporator are all in fluid communication. The evaporator is in thermal communication with the environmental space to influence the temperature of the environmental space. A merchandiser also includes a frame supporting the at least one surface, the linear compressor, the condenser, the expansion device, and the evaporator.

Dual-circuit refrigeration system

Abstract: A refrigeration system and method of refrigeration employ dual refrigeration circuits. Each circuit has an independent compressor, condenser and evaporator. In one refrigeration circuit, the flow of the refrigerant from the condenser to the evaporator is regulated in response to variations in the heat load at the evaporator while, in the other refrigeration circuit, the refrigerant is passed from the condenser to the evaporator at a substantially constant rate of flow. The refrigeration system can be used as a cooling system, including an air conditioning system, and as a heat pump. The evaporator in both circuits may be incorporated within a common heat exchanger as may the two condensers. Additionally, the flow of the refrigerant from the condenser to the evaporator in one refrigeration circuit may be regulated in response to variations in the heat load in the evaporator in that refrigeration circuit by a thermal expansion valve.

Cooling apparatus and a thermostat with the apparatus installed therein

Abstract: A cooling apparatus ( 1 ) has a compressor ( 2 ), a condenser ( 3 ), an expansion valve ( 5 ), an evaporator ( 6 ) and an electric valve ( 10 ), all connected to each other in this order by a piping line to form a refrigeration circuit. The apparatus further has a heating section ( 11 ) and a bypass ( 12 ), and a thermosensitive tube ( 13 ) of the expansion valve is disposed between the heating section ( 11 ) and the electric valve ( 10 ) so that temperature of a refrigerant having left this section is detected before entering this valve ( 10 ). The refrigerant remains as a gas-liquid mixture until it leaves the evaporator ( 6 ) such that temperature of the refrigerant is uniform within the evaporator and equal to the saturation vapor temperature of this refrigerant, and therefore fluctuation in the refrigerant temperature is diminished.

Air conditioner and truck equipped with same

Abstract: A vehicle air conditioner includes a refrigeration cycle system that includes a compressor for compressing refrigerant, a condenser, a pressure reducing means, and an evaporator, and an air conditioning unit, which operates the refrigeration cycle unit, for air-conditioning air in a passenger compartment. In the air conditioner, the compressor is a motor driven compressor driven by one of a battery that is charged by a generator driven by a vehicle power source and an outside commercial electric power source. The air conditioning unit is an integrated unit of the refrigeration cycle system that includes the motor driven compressor disposed on a vehicle roof.

Heat regulation device for motor vehicle`s battery module, has heat regulation unit with refrigerant fluid/air heat exchanger forming evaporator for cold source of heat pump, such that exchanger is called as battery evaporator

Abstract: Device has an air flow circulation unit for circulating air flow (F) across a battery module (B). An enclosure (E) has an air flow guiding unit in which the battery module and an air flow heat regulation unit (32) are housed. The heat regulation unit has a refrigerant fluid/air heat exchanger (28) forming an evaporator for a cold source of a heat pump (12), so that the exchanger is called as battery evaporator.

Air conditioning system

Abstract: The invention is based on a climate control system for a vehicle that is driven by an internal combustion engine ( 10 ), having a heating heat exchanger ( 24 ) which is connected to a coolant loop ( 12 ) of the engine ( 10 ) and is preceded upstream of a blower ( 48 ) by an evaporator ( 44 ), and a compressor ( 50 ) in a refrigerant loop ( 40 ), during a cooling mode, pumps a refrigerant via a gas cooler ( 42 ) and via an expansion valve ( 54 ) to the evaporator ( 44 ) and during a heating mode pumps it to the evaporator bypassing the gas cooler ( 42 ), and between the coolant loop ( 12 ) and the refrigerant loop ( 40 ) a coupling heat exchanger ( 38 ) is provided. It is proposed that the coupling heat exchanger ( 38 ) is disposed upstream of the gas cooler ( 42 ) on the side of the refrigerant loop ( 40 ) on the compression side of the compressor ( 50 ); that a bypass line ( 60 ) is connected parallel to the gas cooler ( 42 ), and the flow through the gas cooler ( 42 ) and the bypass line ( 60 ) is controlled as a function of operating parameters via a switching valve ( 62 ) in the bypass line ( 60 ) and one switching valve ( 64, 66 ) each at the inlet and outlet, respectively, of the gas cooler ( 42 ); and that in the heating mode, the evaporator ( 44 ) serves as a heat source.

Solar energy-air heat pump water heater

Abstract: The present invention relates to a solar-air heat pump water heater, including a solar-air evaporator, a hot-water tank containing submerged condenser coil, a small heat pump compressor and related refrigerating fittings of thermodynamic expansion valve, gas-liquid separator, drying filter and liquid storage device. The solar-air evaporator is formed from the components of solar heat-collecting plate, air conditioning fan, air vent and shell body. The solar heat collector and air heat-exchanger are combined together by adopting compact structure form. The automatic control device of the water heater includes a temperature difference controller for controlling starting and stopping of the fan and a water tank constant temperature device for controlling starting and stopping of compressor.

Air conditioning system

Abstract: PROBLEM TO BE SOLVED: To provide an air conditioning system capable of reducing an excess cleaning time of a connection pipeline without the adjustment of the cleaning time of the connection pipeline.SOLUTION: The air conditioning system comprises the steps of: using an outdoor heat exchanger as a condenser; starting the operation by setting the opening of an expansion valve in each indoor equipment at an initial opening; when detecting the state that an overheat degree of coolant on the downstream side of the indoor heat exchanger being below a specified value for a predetermined time in total sum, by determining that the cleaning of the connection pipeline corresponding to the indoor equipment having the indoor heat exchanger is finished, returning the opening of the expansion valve in the indoor equipment to the initial opening or setting the opening at a prescribed opening; and among pieces of the indoor equipment determined that the total sum time of the state that the overheat degree on the downstream side of the indoor heat exchanger being below the specified value is less than the predetermined time, the opening of the expansion valves in the pieces of the indoor equipment with the large overheat degree is preferentially increased.

Integrated heat exchanger for use in a refrigeration system

Abstract: A refrigeration system includes a multiple stage compressor 10 having at least two stages 12, 14 for sequentially compressing the refrigerant together with a gas cooler 21 connected to the compressor 10 for re-ceiving compressed refrigerant from the last stage 14 of the compressor to cool the same. An evaporator 18 is connected to the gas cooler 21 via an expansion device to receive cool refrigerant therefrom and cool the fluid stream passing through the evaporator 18. A return passage connects the evaporator 18 to the first stage 12 of the compressor and an intercooler 26 is connected between the first stage 12 and the last stage 14 of the com­pressor to cool refrigerant compressed by the first stage 12 and direct the refrigerant cooled thereby to the last stage 14 for further compression. The intercooler 26 and the gas cooler 21 are integrated into a single unit 22 and receive a single cooling heat exchange fluid and the gas cooler 21 has a larger heat transfer surface area than the intercooler 26.

Starting controlling method for frequency-variable air conditioner

Abstract: In the method, expansion valve is controlled to reduce its aperture value to be standrd value is steps when air conditioing is switched on the power and at the same compressor is controlled to raise its start-up frequency to be standard value in steps, the measured outdoor air temperature is compared with designed stardard outdoor air temperature as start-up frequency of compressor and aperture value of expansion value are specified based on it.