Showing papers on "Thermal expansion valve published in 2013"

Air conditioning device

Abstract: PROBLEM TO BE SOLVED: To obtain an air conditioning device allowing dehumidification while supplying a sufficient air flow even when the cooling load is small.SOLUTION: The air conditioning device includes a compressor 1, an outdoor heat exchanger 3, electric expansion valves 4-6, and an indoor heat exchanger 8 which are sequentially connected by a refrigerant pipe 20 to form a refrigeration cycle. The indoor heat exchanger 8 includes a plurality of heat exchangers 8a, 8b, and these heat exchangers are connected to distribution flow paths 21, 22 diverging in parallel from the refrigerant pipe. The respective distribution flow paths are provided with the electric expansion valves 5, 6. The air conditioning device also includes a suction air temperature sensor 14 for detecting temperature of air flowing into the indoor heat exchanger, a discharge pressure sensor 11 for detecting discharge pressure of the compressor, and a suction pressure sensor 10 for detecting suction pressure. In addition, the air conditioning device includes a control means 13 for closing an electric expansion valve corresponding to any of the plurality of heat exchangers when a difference between the temperature detected by the suction air temperature sensor and set temperature is smaller than a predetermined value and when dehumidifying operation is performed during low-load operation.

Theoretical and practical comparison of two-phase ejector refrigeration cycles including First and Second Law analysis

Abstract: This paper compares the standard two-phase ejector refrigeration cycle with a liquid–vapor separator to two alternate, less commonly considered two-phase ejector refrigeration cycles as well as to a conventional cycle with an expansion valve. An analytical comparison of the different ejector cycles' theoretical COP's is presented and used to show that they have the same theoretical COP. Numerical models are used to further compare the cycles in terms of theoretical COP and availability destruction. The results show that the standard two-phase ejector cycle has lower availability destruction and higher Second Law efficiency than the alternate ejector cycles despite having the same theoretical COP. Some advantages and disadvantages of the different ejector cycles that are not accounted for in the theoretical COP are discussed. The potential practical advantages offered by the alternate ejector cycles show that these and other alternate ejector cycles may be worth additional attention in future studies.

Cycling losses in refrigeration equipment: An experimental evaluation

Abstract: Cycling losses may be defined as those inefficiencies that reduce the performances of units during the transient period. They may be quantified by comparing the Energy Efficiency Ratio (EER) of a cycling unit and the EER of the same unit working continuously. The on-off control is the most widespread strategy for modulating; therefore, a reliable evaluation of cycling losses is fundamental to assess the EER of the system. The mentioned losses have been experimentally evaluated on a test rig, and logged data demonstrate a loss up to 13% with respect to steady operations when the load factor is lower than 10% and a Thermostatic Expansion Valve (TEV) is used. The insertion of a solenoid valve in series with the TEV can reduce the losses but the best results are obtained by using the Electronic Expansion Valve (EEV) instead of the TEV.

Organic flash cycles for efficient power production

Abstract: This disclosure provides systems, methods, and apparatus related to an Organic Flash Cycle (OFC). In one aspect, a modified OFC system includes a pump, a heat exchanger, a flash evaporator, a high pressure turbine, a throttling valve, a mixer, a low pressure turbine, and a condenser. The heat exchanger is coupled to an outlet of the pump. The flash evaporator is coupled to an outlet of the heat exchanger. The high pressure turbine is coupled to a vapor outlet of the flash evaporator. The throttling valve is coupled to a liquid outlet of the flash evaporator. The mixer is coupled to an outlet of the throttling valve and to an outlet of the high pressure turbine. The low pressure turbine is coupled to an outlet of the mixer. The condenser is coupled to an outlet of the low pressure turbine and to an inlet of the pump.

Dual evaporator refrigeration system using zeotropic refrigerant mixture

Abstract: A dual evaporator refrigerator appliance includes a compressor, a condenser, a first evaporator, a second evaporator and a separating component coupled to the condenser and an input of the first evaporator and an input of the second evaporator and configured to separate a refrigerant stream received by the condenser into a first refrigerant stream and a second refrigerant stream. The refrigerant stream received by the separating component comprises a zeotropic refrigerant mixture. The first evaporator and the second evaporator are configured to substantially simultaneously receive the first refrigerant stream and the second refrigerant stream, respectively.

Air conditioning device

Abstract: The objective of the invention is to provide an air conditioning device capable of improving heating starting performance or defrosting restorability The air conditioning device is provided with a compressor which is used for compressing a refrigerant, an indoor heat exchange device through which the refrigerant compressed by the compressor flows in heating operation processes, an electric expansion valve through which the refrigerant condensed by the indoor heat exchange device flows, an outdoor heat exchange device through which the refrigerant expanded by the electric expansion valve flows, an external air temperature detection assembly which is used for detecting external air temperature, and a control part which is used for controlling opening degree of the electric expansion valve The air conditioning is characterized in that the control part is used for fixing the opening degree of the electric expansion valve according to set time and set opening degree when the heating operation is started, and the opening degree is correspondingly changed based on the temperature difference between the temperature detected by the external air temperature detecting assembly and the air saturation temperature at an inhalation side of the compressor when the heating operation is started

Air conditioning system

Abstract: PROBLEM TO BE SOLVED: To provide an air conditioning system capable of recovering oil into a compressor from a refrigerant circuit by connecting a plurality of outdoor units in parallel with each of one or more indoor unitsSOLUTION: A control device of the air conditioning system causes a four-way valve to switch a flow channel of each outdoor circuit element into a refrigerating channel, stops each indoor fan, and controls the opening of each indoor expansion valve, the rotation of each compressor, and the rotation of each outdoor fan to the predetermined pressure-reducing opening, the predetermined compressor rotation, and the predetermined fan rotation in step S5 as the start of oil recovery operation The predetermined pressure-reducing opening, the predetermined compressor rotation, and the predetermined fan rotation are set to keep the refrigerant from each indoor heat exchanger to each compressor overheated steam which is similar to moist steam

Energy efficient dehumidifying refrigeration system

Abstract: An evaporator setpoint temperature for a refrigeration system is adjusted by an electronic control module to maximize a ratio of volume of condensate produced per unit of electricity consumed. When the control module detects a change in the relative humidity of air entering an evaporator in the refrigeration system, the module determines the new dew point for the air, compensates the dew point value by a predetermined offset value, and changes the setpoint for refrigerant temperature in the evaporator to the compensated dew point value. The control module operates the refrigeration system to drive the evaporator temperature to the compensated dew point value. Refrigeration system parameters measured and modified by the control module include operating speed of compressors, number of operating compressors, refrigerant flow through an expansion valve, compressor suction pressure, and fan speeds for the condenser and evaporator.

Expansion valve injection control method and system

Abstract: The invention discloses an expansion valve injection control method and system. The control method comprises the following steps of injection start judgment: determining the target supercooling degree in the cooling mode, comparing the current supercooling degree and the target supercooling degree, starting the injection mode when the current supercooling degree is less than or equal to the sum of the target supercooling degree and an error D1, calculating the start index in the heating mode, and starting the injection mode when the start index is more than or equal to 1 according to judgment; injection shutoff judgment: shut off the injection mode when the injection electronic expansion valve is closed to the minimum degree and the current supercooling degree is more than or equal to the sum of the target supercooling degree and an error D2. In the control method provided by the embodiment, a variable frequency injection enthalpy-increasing compressor is combined with a multi-line system, the system can enter or exit the injection state at the appropriate time via information feedback of position sensors of the system, air supply can be enabled to be in an optimal state by dynamically adjusting the opening of the electronic expansion valve during the injection process, and the advantages of the air supply enthalpy-increasing compressor in improving the heat generation at high/low temperature and the energy efficiency and greatly increasing the main channel supercooling degree in the cooling mode can be embodied to the largest extent.

Hybrid heat pump boiler system

Abstract: The hybrid heat pump boiler system comprises a water tank unit 300, a boiler unit 400, and an indoor 100 and outdoor unit 200 that together form a heat pump The outdoor unit has a compressor 210 to compress a refrigerant, a 4-way valve 220 to change a flow-path of the refrigerant discharged from the compressor, a first heat exchanger 230 to allow refrigerant from the 4-way valve to pass through and exchange thermal energy with water from the water tank unit, a first expansion valve 270 to expand refrigerant from the first heat exchanger during a water and space heating operation, and a fan coil unit 250 to receive refrigerant from the first expansion valve The boiler unit has a heat pipe 470 connected with an exhaust gas recovery heat exchanger 401 The heat pipe may pass thermal energy captured from the boiler unit to the outdoor units fan coil unit when defrosting of the coil 252 is required, for example, in winter Alternatively, the heat pipe may pass the thermal energy to an auxiliary tank (460, figure 5) A second expansion valve 280 is provided and may be used with the indoor unit to cool an interior space

Apparatus for supplying air of fuel cell vehicle

Abstract: An apparatus that efficiently supplies air to a fuel cell within a vehicle. In particular, a compressor compresses air and supplies a first portion of the compressed air to an evaporator and a second portion to a heat exchanger. A drain valve also discharges condensate water from a fuel cell to the evaporator so that the evaporator receives some of both the compressed air and the condensate water and supplies air humidified by evaporation of the condensate water directly to the fuel cell. A heat exchanger also receives some of the compressed air, transfers heat from the received compressed air to the evaporator, and discharges cooled air to a humidifier. The humidifier receives and humidifies the cooled air and supplies the humidified air to the fuel cell.

Expansion valve components, one-way expansion valve and two-way circulation expansion valve

Abstract: The invention provides expansion valve components, a one-way expansion valve and a two-way circulation expansion valve, belonging to the technical field of refrigeration of variable frequency air conditioners. The invention solves the problem that the service life of a valve is shortened due to frequent abrasion of the conventional valve cores and the conventional vale bases. The two-way circulation expansion valve comprises a valve block which is provided with two parallel channels, wherein each channel is provided with an inlet end and an outlet end; an expansion valve component which is provided with a damping structure is connected to each outlet end; a bypass hole for communicating an outlet of the expansion valve component on one channel with the inlet end of the other channel is formed in the valve block; and a protection cover for preventing a medium from being leaked when flowing through the bypass hole and the outlet is welded at each outlet end. The two expansion valve components are arranged in parallel to ensure that a function of two-way circulation is realized; and the movement of a valve core is reduced by the damping structures, so that the service life of the expansion valve components is prolonged and the energy efficiency ratio of the expansion valve components is improved, thereby being of great significance for energy conservation and emission reduction.

Heat Pump Apparatus

Abstract: A heat pump apparatus is provided The heat pump raises the water temperature during a hot-water supply without using a separate heat source such as a heater The heat pump apparatus includes an outdoor unit including a first compressor, a first heat exchanger, and a first expansion valve The heat pump apparatus includes an indoor unit including a second heat exchanger and a second expansion valve, a hydro unit including a second compressor, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a third expansion valve, a fourth expansion valve, and a fifth expansion valve The heat pump apparatus includes a refrigerant flow path switching unit to switch among flow paths, and a water flow path switching unit to switch between flow paths of the water

Exergy efficiency and irreversibility comparison of R22, R134a, R290 and R407C to replace R22 in an air conditioning system

Abstract: This work presents an experimental comparison of exergy efficiency (EE), irreversibility at the process 1–2 (evaporator exit to compressor inlet), 2–3 (compressor inlet to condenser inlet), 3–4 (condenser inlet to expansion valve inlet), 4–5 (expansion valve inlet to evaporator inlet) and 5–1 (evaporator), and coefficient of performance (COP) of R22, and its substitutes R134a, R290 and R407C in vapor compression refrigeration system (VCRS) of an air conditioner. In addition, the effects of air temperature in the freezer with reference to environment states on irreversibility and EE have been investigated. At −18°C air temperature in the freezer, 33°C reference environment state and 42% relative humidity refrigerants R22 and its substitutes R134a, R290 and R407C VCRSs the total irreversibilities are 665.7, 753.5, 582.1 and 677 W, and EEs are 22.9, 14.2, 26.5 and 20.6%, respectively. The refrigerant R290 is the best performer among candidate refrigerants but it suffers from flammability. Thus, R407C can considerably be used to replace R22.

Air circulation battery box temperature management system of electric automobile

Abstract: The invention discloses an air circulation battery box temperature management system of an electric automobile. The air circulation battery box temperature management system of the electric automobile comprises an air circulating device, a refrigerant circulating device and a cooling liquid circulating device. An air circulating system comprises an air blower, a battery box radiator, a battery box and a circulating air channel. A refrigerant circulating system comprises an electric air conditioner compressor, a condenser, a pressure switch, an electromagnetic switch, an expansion valve, a heat exchanger and connecting pipelines. The air blower, a battery box temperature sensor and all valve bodies arranged in the pipelines are connected with a vehicle controller. The air circulation battery box temperature management system of the electric automobile can ensure normal work of lithium batteries, air flow produced by the air blower blows the battery box radiator to enable energy of cooling liquid cooled by the refrigerant circulating system and heated by the cooling liquid circulating system to be blown into the battery box under the control of the vehicle controller mainly according to temperature signals sent by the battery box sensor, and therefore the temperature in the battery box is kept in a reason temperature range all the time.

Heat-pump air-conditioning system

Abstract: The utility model discloses a heat-pump air-conditioning system, which comprises an indoor heat exchanger, an outdoor heat exchanger, a first pipeline, an expansion valve, a compressor, a four-way valve, a heat accumulation loop, a heat accumulator and a hot air bypass loop, wherein the indoor heat exchanger and the outdoor heat exchanger are connected through the first pipeline; the expansion valve is connected to the first pipeline in series; the compressor is used for compressing refrigerant steam; the four-way valve is connected with the input end and the output end of the compressor, the indoor heat exchanger and the outer heat exchanger; one end of the heat accumulation loop is connected between the expansion valve on the first pipeline and the outdoor heat exchanger, a first two-way valve and a heat accumulator wrapped on the outer wall of the compressor are connected to the heat accumulation loop in series, and the other end of the heat accumulation loop is connected with the input end of the compressor; one end of the hot air bypass loop is connected between the output end of the compressor and the indoor heat exchanger, the other end of the hot air bypass loop is connected with the outdoor heat exchanger; and a second two-way valve and a throttling device are connected to the hot air bypass loop in series. A refrigerant flows into the expansion valve for cooling from the indoor heat exchanger, so that the temperature of the refrigerant flowing into the heat accumulator is reduced, the temperature difference between the refrigerant flowing into the heat accumulator and the heat accumulator is improved and the defrosting effect is effectively improved.

Method For Detection Of Loss Of Refrigerant

Abstract: A method is provided for detecting in real-time a refrigerant charge loss in a refrigerant vapor compression system. If both a sensed evaporator outlet superheat exceeds a target evaporator outlet superheat by at least a preset amount of superheat and a sensed degree of openness of an electronic expansion valve exceeds a preset degree of openness for a preset time of period, and a sensed air temperature of either a flow of supply air having traversed the evaporator or a flow of return air returning to the evaporator is changing at a rate less than preset air temperature rate of change, a service alarm is generated indicating a loss of charge warning.