Showing papers on "Thermal expansion valve published in 1991"

Distributed and non-steady-state modelling of an air cooler

Abstract: The refrigerant flow inside the coils of a dry expansion plate-finned air cooler can be distinguished into two completely different types: two-phase flow and single-phase flow. The most difficult part of non-steady-state modelling of an air cooler is to describe the liquid and vapour mass transport phenomena occurring in the two-phase flow region, as this determines the boundary position between the two regions and then the superheat temperature, which is in turn the feedback signal of the thermostatic expansion valve. In fact, the mass transport is mainly governed by the momentum exchange between refrigerant liquid and vapour, which is usually called slip-effect. Because the momentum or force equilibrium is so fast compared to the thermal equilibrium, the slip-effect can be considered as a steady-state phenomenon. With this assumption, the mass transport in an air cooler can be described by using a simple propagation equation. The steady-state slip-effect, however, is found by solving the momentum equations for one-dimensional two-phase flow using advanced computer packages such as phoenics . This paper presents the derivation of the equations in non-steady-state modelling of an air cooler as well as the results obtained from the model. Because the model is purely distributed, it is applicable to various kinds of tube circuit arrangements of air coolers. The purpose of the model is studying and optimization of non-steady-state behaviour of refrigerating systems with capacity control.

Automotive refrigeration system requiring minimal refrigerant

Abstract: The potential for leakage of CFCs, HCFCs, HFCs and HCs to the atmosphere as a result of leakage in vehicular refrigeration systems is reduced by employing conduits (42, 58 and 63) of relatively short length to interconnect closely grouped system components including a compressor (38), a condenser (44) and an evaporator (62). The condenser (44) includes a liquid flow path (46) in heat exchange relation with a refrigerant flow path (48) and the same is connected by conduit (52) to heat exchanger (36). The evaporator (62) also includes a liquid flow path (65) in heat exchange relation with a refrigerant flow path (60) and the same is connected by conduits (66, 67) to at least one heat exchanger (68, 69) remote from an engine compartment (22) in which the compressor (38), condenser (44) and evaporator (62) are housed. The close proximity of the components minimizes the charge of refrigerant required and thus reduces the amount of refrigerant that may potentially leak from the system.

Heat pump having an accumulator with refrigerant level sensor

Abstract: A ground source heat pump comprising an indoor coil circuit and an outdoor coil circuit utilizes a scroll compressor to pressurize the refrigerant. The outdoor coil may comprise ground coils formed from copper tubing into a spiral configuration. A charge control device controls the volume of refrigerant in the system in heating and cooling modes. A restrictor in parallel with a thermal expansion valve permits a base flow of refrigerant into the outdoor coil in heating mode. An accumulator is provided with a level switch controlling a solenoide value connected in parallel to a thermal expansion value feedig the indoor coil. The scroll compressor includes a discharge port operating in conjunction with a solenoid valve to trap high pressure refrigerant in the condenser circuit during compressor off cycles. Means for closing off one of the ground coils to reduce the effective length of the outdoor coil is provided.

Thermostatic expansion valve with electronic controller

Abstract: A refrigeration system employing a mechanical thermal expansion valve with a self-heated thermistor sensing saturation temperature at a high pressure inlet and a second thermistor sensing saturation temperature at the evaporator outlet. A microprocessor based controller compares the sensed temperature with stored limits and provides output signals to a relay for cycling the condenser fan responsive to high side pressure and the compressor clutch responsive to the low pressure side temperature. For low pressure drop evaporators, the second thermistor may be disposed at the evaporator inlet.

Comparative study of irreversibilities in an aqua-ammonia absorption refrigeration system

Abstract: Irreversibilities in components of an aqua-ammonia absorption refrigeratio system (ARS) have been determined by second law analysis. The components of the ARS are as follows: condenser, evaporator, absorber, generator, pump, expansion valves, mixture heat exchanger and refrigerant heat exchanger. It is assumed that the ammonia concentration at the generator exit is, independent of the other parameters, equal to 0.999 and at the evaporator exit the gas is saturated vapour. Pressrre losses between the generator and condenser, and the evaporator and absorber are taken into consideration. In the results the dimensionless exergy loss of each component, the exergetic coefficient of performance, the coefficient of performance and the circulation ratio are given graphically for each different generator, evaporator, condenser and absorber temperature.

Refrigerating apparatus and method of controlling refrigerating apparatus in accordance with fuzzy reasoning

Abstract: A refrigerating apparatus which is capable of accurate and swift correspondence to a transient change of a refrigerant circuit or an accumulated deviation of the degree of superheat of a refrigerant, thereby releasing the state in which the liquid refrigerant is flowing back to the compressor and the overheated state, and a method of controlling such a refrigerating apparatus. The refrigerating apparatus comprises a refrigerant circuit composed of a condenser, an expansion valve and an evaporator which are connected to each other in series, a means for detecting the evaporating temperature of the refrigerant, a means for detecting the exit temperature of the evaporator, and a control means for controlling the opening of the expansion valve on the basis of the evaporating temperature of the refrigerant and the exit temperature of the evaporator in accordance with a fuzzy reasoning.

Multi-type air conditioner system with optimum control for gaseous flow adjustment valve and liquid expansion valve

Abstract: An outdoor unit has a compressor and an outdoor heat exchanger. Each of a plurality of indoor units has an indoor heat exchanger. The outdoor unit is connected in parallel with the plurality of indoor units to form a multi-type air conditioner system having a plurality of refrigeration cycles. A plurality of gaseous flow adjustment valves are provided to the gaseous sides of the indoor units, respectively. A plurality of liquid expansion valves are provided to the liquid sides of the indoor unit, respectively. A refrigerant super-heat degree detector detects a refrigerant super-heat degree of the outdoor heat exchanger or the indoor heat exchangers. A controller controls a capacity of the compressor and opening degrees of the gaseous flow adjustment valves in accordance with required capacities of the indoor units, and controls the liquid expansion valves in accordance with a detection output from the refrigerant super-heat degree detector such that the refrigerant super-heat degree becomes a predetermined value. The controller includes an optimum control unit for controlling opening degrees of at least one of the gaseous flow adjustment valves and the liquid expansion valves in accordance with operating states of the multi-type air conditioner system such that the operating states become optimum, respectively.

Hot gas defrost refrigeration system

Abstract: A hot gas defrost refrigeration system has a compressor, a condenser, a receiver, an evaporator, interconnected by fluid passage means and incorporating valve means to cause refrigerant to flow sequentially through the compressor, condenser, receiver and evaporator to the compressor during the refrigeration cycle. The refrigeration system includes a superheater and defrost passage means, including valve means, connecting the evaporator outlet to the condenser inlet and connecting the condenser outlet through the superheater to the compressor inlet, bypassing the receiver. The passage means connecting the compressor outlet with the evaporator inlet includes a superheat passage in heat exchange relationship with the superheater for transferring heat from the refrigerant discharged from the compressor outlet to the refrigerant delivered to the compressor inlet during the defrost cycle. During the defrost cycle, refrigerant flows sequentially from the compressor to the evaporator, then through the defrost passage means to the condenser and then to the superheater to the compressor. The condenser is utilized as a reevaporator during defrost and the superheater exchanges heat between compressor inlet and suction refrigerant to enhance system operation during the defrost cycle.

Multi-chamber type air conditioner

Abstract: PURPOSE:To enable a simultaneous operation of a cooling operation and a heating operation to be carried out by a method wherein two outdoor heat exchangers are selectively changed over between an evaporator and a condenser. CONSTITUTION:A four-way valve 22, the first two-way valve 27 and the second two-way valve 28 are provided, the first and second outdoor heat exchangers 23 and 25 are selectively changed over between an evaporator and a condenser and operated. Branch devices 40a to 40d are provided, and each of indoor devices 50a to 50d is individually operated for its cooling and heating operation. In the case that a ratio of the cooling operation to the heating operation at each of the indoor devices is close to one and evaporating and condensing capabilities at the outdoor heat exchanger required in the cooling or heating cycle, are small, the outdoor device heat exchanger 25 is stopped in its operation by closing the two-way valve 27, a degree of opening of an electric expansion valve 24 at the outdoor device is adjusted, a heat exchanging capability is reduced and the operation is carried out at the most suitable state. In the case that an indoor thermal load is reduced more than a minimum capability of a variable capability compressor 21 and the cycle operating point is displaced from its most suitable point, the two-way valve 28 is communicated with a suction pipe 31 to cause the heat exchanger 25 to be operated as the condenser and further to cause the heat exchanger 23 to be operated as the evaporator and then a freezing cycle is carried out at the most suitable point.

Refrigeration systems with multiple evaporators

Abstract: A refrigeration system suitable for use in household refrigerators having a fresh food compartment, a freezer compartment and an intermediate temperature compartment is provided. The system includes a first expansion throttle, a first evaporator for providing cooling to a freezer compartment, first, second and third compressors, a condenser, a second expansion throttle, a second evaporator for providing cooling to a fresh food compartment, a third expansion throttle, and a third evaporator for providing cooling to an intermediate compartment. All the above elements are connected in series, in that order, in a refrigerant flow relationship. A first phase separator connects the second evaporator to the third expansion throttle in a refrigerant flow relationship and provides intercooling between the second and third compressors. A second phase separator connects the third evaporator to the first expansion throttle in a refrigerant flow relationship and provides intercooling between the first and second compressors. An accumulator is connected between the first evaporator and the first compressor to regain lost cooling capacity in the event liquid refrigerant is discharged from the first evaporator.

Control arrangement for a refrigeration apparatus

Abstract: A refrigeration system having compressor controls responsive to the heat load on the system. Each selected evaporator of the system has a thermostatic switch unit which includes an associated temperature sensor in proximity to the evaporator. The thermostatic switch unit has an operating range with ON and OFF threshold values and function to operate an electromagnetic valve which controls the refrigerant admitted to the evaporator. The heat load to which the compressor controls are responsive is derived from the accumulated ON and OFF times of the switch insert.

Method of using a thermal expansion valve device, evaporator and flow control means assembly and refrigerating machine

Abstract: The expansion valve 103 of the refrigerating machine is controlled by the difference between the pressure in a bulb 104 containing a fixed amount of fluid and the pressure in the evaporator 2. The bulb is mounted in the discharge pipe 1 of the evaporator and is heated by a resistor. In the absence of droplets of liquid refrigerant in the flow through the discharge pipe, i.e when the refrigerant flow rate tends to become too low with respect to the cold demand, the resistor heats up the fluid in the bulb, the pressure in the bulb increases and moves the expansion valve to a more opened position. As soon as droplets hit the bulb in the discharge pipe, said droplets cool down the bulb despite the heating effect of the resistor and the expansion valve is moved to a more closed position. Thus, the flow rate control uses variations in heat transfer coefficients in the discharge pipe rather than superheat temperature in the discharge pipe. The evaporator may be small-sized because it does not have to produce superheat.

Multi-system air conditioner

Abstract: A multi-system air conditioner comprises an exterior unit including a compressor and a plurality of interior units, each being installed in a room and including a heat exchanger and an expansion valve therefor. An opening degree of the expansion valve in an interior unit is controlled based on not only the superheat degree of the compressor but also the room temperature difference. Further, the control based on the superheat degree is carried out by means of the fuzzy logical calculation on superheat degree value. A rotational speed of the compressor is controlled based on not only the load capacity of the room but also the room temperature difference. Further, a control based on the fuzzy logical calculation on the pressure value is added. A feed forward control is also added so as to shorten the transient time.

Transport refrigeration system having means for achieving and maintaining increased heating capacity

Abstract: A transport refrigeration system of the type which holds a set point by operating in heating and cooling cycles. The system includes a compressor, a condenser and an evaporator each having inlet and outlet ports. A three-way valve receives compressed gas discharged from the compressor and directs it selectively to first and second outlets. First outlet of the three-way valve directs hot compressor gas to the condenser for operation of the system in a conventional cooling cycle. A hot gas conduit is provided which connects the second outlet of the three-way valve directly to the inlet of the evaporator. A branch line extends from the hot gas line to the line interconnecting the condenser and the evaporator, upstream of the receiver. Another refrigerant line extends from the outlet of the condenser to establish fluid communication with the line interconnecting the outlet of the evaporator with the compressor suction port. Appropriate valve means are provided in the refrigerant lines such that, when appropriately actuated, the three-way valve directs hot gas only to the receiver. The portion of the liquid line which is downstream of the receiver, the hot gas line, and the line interconnecting the condenser outlet with the compressor suction line all are placed in fluid communication with the suction side of the compressor. The compressor then serves to draw down this portion of the refrigeration system to a low pressure thereby withdrawing the refrigerant therefrom and directing it via three-way valve and a portion of the hot gas line to the receiver.

Method of optimising the performance of refrigerant vaporizers including improved frost control method and apparatus

Abstract: A method is described for the performance optimization of refrigeration devices fed with refrigerant, in particular of air refrigeration devices in which a setting value is formed for an electrically or electronically operatable expansion valve in dependence on different temperature measurements continually ensures the ideal filling of the vaporizer. The invention includes a method of optimising the performance of a fan air refrigerator and of determining the ideal timepoint for defrosting is described, with the time for defrosting being determined by a comparative monitoring of a temperature difference, on the one hand, and a time related monitoring of the refrigerant throughflow, on the other hand. In addition the cold room temperature is regulated by the supply air sensor by switching on and switching off the compressor.

Refrigerant handling system with inlet refrigerant liquid/vapor flow control

Abstract: A refrigerant recovery system includes a compressor and an evaporator connected to the compressor inlet for evaporating refrigerant passing therethrough to the compressor inlet from refrigerant equipment under service. A sensor is coupled to the system input for detecting presence of liquid phase refrigerant. A valve is connected to the compressor inlet in parallel with the evaporator for bypassing refrigerant from the evaporator to the compressor inlet when the sensor indicates that liquid refrigerant is absent at the system input. The liquid refrigerant sensor takes the form of an open canister between the system input and the evaporator, and a liquid level sensor coupled to the canister for sensing level of liquid refrigerant collected within the canister. A solenoid valve is connected in parallel with the evaporator, and is responsive to the liquid level sensor for opening the valve and bypassing the evaporator in the absence of liquid refrigerant within the canister. In this way, when input refrigerant is already in vapor phase, such refrigerant is bypassed to the compressor inlet, eliminating undesirable superheating of the refrigerant within the evaporator.

Refrigerant power unit and method for refrigeration

Abstract: A refrigerant power unit includes a closed piping loop containing refrigerant. The refrigerant is pumped to an evaporator (12) where it changes to a saturated vapor. It is directed across a generator (24) absorbing additional heat energy and changing to a super-heated hot gas. The refrigerant is directed through the nozzles in a turbine (30) and impinges upon turbine blades. As the refrigerant passes around the turbine blades, it expands and exits the turbine blades in an axial direction. The enthalpy, temperature and pressure of the refrigerant drops, reducing the refrigerant to a saturated vapor. The refrigerant then enters a condenser (36) heat exchanger dissipating heat into the surrounding medium, reducing the enthalpy of the refrigerant, changing the refrigerant into a liquid before entering the receiver tank. A pump (18) draws the liquid refrigerant from the receiver tank and pressurizes the system. The refrigerant is directed to the inlet of the evaporator, completing the cycle through the refrigerant power unit. A more detailed system includes an additional piping segment, between the receiver tank and the generator, which contains an evaporator (64), a compressor (74) and a motor (76). Another system includes a second evaporator (102) between the evaporator (100) and the generator (118). It includes a second closed piping loop containing a compressor (130) and a motor (136) between the first and third evaporators. The loop also provides the heating refrigerant for the first evaporator coil and the coolant refrigerant inside the third evaporator coil.

An apparatus and method for heating and cooling with a refrigerant

Abstract: An apparatus and a method for heating and cooling with a refrigerant wherein the refrigerant is compressed by a compressor (1), and circulated to and from the compressor (1) through a condenser (3), an expansion valve (5) and an evaporator (7), in this order. A first fluid is heated with the heat generated in the condenser (3), and a second fluid is cooled with the cooling effect or cold generated in the evaporator (7). When heat is low and a temperature of the first fluid is decreased, the flow passages of the refrigerant are changed from entering into the evaporator (7) to entering into a second heat-exchanger (14) wherein the refrigerant is heated, and the heated refrigerant is entered into the compressor (1) and circulated. When the cooling effect or cold is low and a temperature of the second fluid is increased, the flow passages of the refrigerant are changed from entering into the condenser (3) to entering into a first heat exchanger (11) wherein the refrigerant is cooled, and the cooled refrigerant is entered into the evaporator (7) and circulated.

Variable area refrigerant expansion device having a flexible orifice

Abstract: A refrigeration expansion valve meters the flow of refrigerant therethrough through a flexible orifice that varies in cross sectional area as a function of the pressure differential across the valve. The flexible orifice is provided in a tubular elastomeric element that is supported at opposite ends by rigid support means. A rigid spacer means is provided for engaging the support means to prevent the pressure differential of the refrigeration system from exerting an axial force on the flexible flow metering element.

Controller for electrically driven expansion valve of refrigerating cycle

Abstract: A valve controller which controls the opening degree of an electrically driven expansion valve mounted in the refrigerating cycle, in accordance with a difference between a refrigerant saturation temperature of an outdoor heat exchanger detected with a first temperature sensor and a refrigerant temperature at the suction port of a compressor detected with a second temperature sensor. A sensor error correcting unit is provided whereby a detected temperature error is calculated in accordance with the outputs of the first and second temperature sensors exposed in an atmospheric air having a specific temperature, and in accordance with the detected temperature error, a difference between the refrigerant saturation temperature and the refrigerant temperature at the suction port of the compressor is corrected.

Method for operating an open show-case

Abstract: This open show-case has inner and outer air ducts, a first evaporator and a first blower in said inner duct (an inner evaporator and an inner blower, respectively), and a second evaporator and a second blower in said outer duct, said blowers circulating the air to form at least two layers of air curtains running between respective upper ports at the upper end of the front opening of said show-case and respective lower ports at the lower end of said opening. The show-case is operated by: providing high pressure refrigerant only through the inner evaporator via a decompression valve to thereby evaporate the refrigerant therein during refrigeration operation by the inner evaporator, without passing the refrigerant through the outer evaporator; and providing high pressure refrigerant to the inner evaporator and to the outer evaporator via a decompression valve during defrosting operation for the inner evaporator, with the outer blower driven at a higher speed than a normal speed and the inner blower driven in a reverse direction at a slower speed than a normal speed.

Evaporator with integral liquid sub-cooling and refrigeration system therefor

Abstract: An improved refrigeration evaporator having a first heat exchange element including a fluid inlet and a fluid outlet, for cooling a fluid stream traversing the evaporator by evaporating a volatile refrigerant liquid in heat exchange relation to the fluid stream. The volatile refrigerant liquid is supplied to the evaporator at relatively high saturated condensing temperature and slightly subcooled. The improvement in the refrigeration evaporator comprises a second heat exchange element, positioned in the fluid stream entering the first heat exchange element. The second heat exchange element cools and thereby further subcools the volatile refrigerant liquid prior to the refrigerant liquid entering the first heat exchange element via a pressure reducing device. The fluid stream being cooled may be either gas or liquid and the evaporator may be of the type best adapted for the type of fluid being cooled.

Automotive air-conditioner

Abstract: PURPOSE:To effectively collect energy held in air discharged during ventilation by arranging the first and the second heat exchanger in the front of a car room and the third heat exchanger in the rear of the car room, and in either case of cooling and heating, making the third heat exchanger function as an outdoor heat exchanger. CONSTITUTION:The first heat exchanger 12 and the second heat exchanger 14 are severally arranged in the first chamber 6 and the second chamber 7 in the front of a car room 2, and the third heat exchanger 16 is arranged in the third chamber 8 in the rear of the car room 2. During cooling, refrigerant compressed by a compressor 18 is sent from the third heat exchanger 16 to the first heat exchanger 12, and after exchanging heat with air taken in from the outside of the car in the heat exchangers 16, 12, decompressed by an expansion valve 23 and then led to the second heat exchanger 14. In the heat exchanger 14, the refrigerant exchanges heat with the air supplied into the car room 2 to cool the air. The air discharged from the car room 2 by ventilation is led to the third heat exchanger 16 in the rear of the car room 2 to absorb energy held in the air.

Cooling device and method with multiple cooled chambers and multiple expansion means

Abstract: A cooling device having a refrigeration chamber (1) and a freezer chamber (3), a refrigeration plant having an evaporator (15) and condenser (18), a compressor (16) and air flow passageways (5, 8, 11) for conducting air flow across the evaporator and through the refrigerator and freezer. Capillaries of different size (19, 20) control the flow of refrigerant from the condenser to the evaporator to control the temperature of the evaporator. A pressure device (36) produces the air flow through the passageways to the refrigerator and freezer. Motorized valves (30, 31) are operated by temperature sensors within the refrigerator and freezer to control the flow of air therethrough. A variable temperature compartment (4) may be provided and connected to the airflow passages, with a flow control valve (32) for maintaining a temperature therein set by the user.

Sensor and control system for an automotive air conditioning system

Abstract: An air conditioning system including a refrigerant circulation route (21), a compressor (23), a condenser (24), an expansion valve (31), an evaporator (25) and a pressure sensor (30) for detecting pressure in the circulation route (21) comprises a refrigerant phase detecter (41, 51) provided on the circulation route (21) between the condenser (24) and the evaporator (25) where the refrigerant should be in a liquid phase for detecting whether the refrigerant is in a liquid phase or in a vapor phase and a control for determining whether the compressor (23) is in a locked state in accordance with the signals from the refrigerant phase detecter (41, 51) and the pressure sensor (30) The air conditioning system can precisely determine and detect both compressor lock up and refrigerant leakage without providing a rotation detecting sensor for the compressor (23)

Sensing refrigerant temperature in a thermostatic expansion valve

Abstract: A mechanical refrigerant thermal expansion valve (10) has a sensing port (20) sealed with a cupped shape closure (30) received therein and sealed about the cup rim A cover assembly (34) is removeably attached to the valve over the cup with a thermistor (60) extending into the cup (30) which is filled with thermally conductive grease for thermal conductivity between the cup (30) and the thermistor (60) The cover assembly (34) has an electrical connector (40) provided thereon The thermistor (60) is preferably mounted on printed circuit board potted in the cover (34) which may include electronic signal logic and power switching circuitry

Multi-system air-conditioning machine in which outdoor unit is connected to a plurality of indoor units

Abstract: Electric expansion valves are provided midway along liquid-side pipes connected to indoor units. Electric flow control valves are provided midway along gas-side pipes connected to the indoor units. The indoor units detect air-conditioning loads, and a capability of a compressor is controlled in accordance with the sum of the air-conditioning loads. At the same time, the opening degrees of the flow control valves are controlled in accordance with the individual air-conditioning loads of the indoor units. In the heating operation mode, a high-pressure-side pressure of a refrigeration cycle is detected. When the high-pressure-side pressure becomes a preset value or more, an expansion valve and a flow control valve corresponding to an indoor unit whose operation is stopped are opened to predetermined opening degrees.

Performance Simulations of Twin-Screw Compressors with Economizer

Abstract: In a compressor refrigeration plant with an economizer system, the regular expansion valve is replaced by two valves and an intermediate pressure vessel. The refrigerant which is vaporized after the first valve is injected via the compressor economizer inlet to a thread under compression. The economizer arrangement increases the refrigeration capacity and improves the coefficient of performance (COP). In this paper a performance simulation computer program for twin-screw compressors with an economizer arrangement is presented. Comparisons of economizer performance for different arrangements are often difficult to carry out if real tests have not been run, as the performance is dependent on the intermediate pressure and this pressure is not the same for different arrangements. Such comparisons can be made with the simulation program. Examples are presented for an economizer arrangement combined with external liquid subcooling and for a two-stage economizer arrangement.

Multi type air conditioner

Abstract: PURPOSE:To facilitate confirmation work for piping error by detecting the changes in the temperature of an indoor heat exchanger and a gas branch pipe where refrigerant is distributed and indicating said changes in comparison with an on/off valve which is open when carrying out a test run in a refrigerating circulation cycle CONSTITUTION:In a cooling cycle, a high temperature and high pressure liquefied refrigerant condensed in an outdoor heat exchanger, is turned into low temperature and low pressure refrigerant when it passes by a second motor-driven expansion valve 23 which is open, and flows into an indoor heat exchanger 22, then it is vaporized there As a result, the indoor heat exchanger 22 is turned into low temperature state, which also turns a gas branch pipe where the vaporized refrigerant passes by into low temperature state, thus producing temperature changes During a test run, an operation control means 42 receives each detection temperature transmitted from heat exchanger temperature sensors 31, room temperature sensors 33, and each gas branch pipe temperature sensors 32 installed to the respective indoor units A to D, and displays piping connection states on an indicator 43 based on the detection results of each temperature sensor Therefore, this construction makes t possible to detect successively in what equipment a temperature drop is produced out of the indoor heat exchanger 22, and the gas branch pipes 19-1 to 19-4, and discriminate the piping states

Cooling machine and an optimalized thermostatic expansion valve therefor

Abstract: The invention relates to a cooling machine having a cooling cycle in which coolant circulates, which cooling cycle comprises: 1) an evaporator: 2) a compressor; 3) a condenser; 4) a thermostatic expansion valve whereof a bulb is connected to a coolant outlet of the evaporator; and integrating control circuit for the thermostatic expansion valve, comprising: a liquid-sensitive sensor placed in the cooling cycle for direct contact with coolant and connected via a voltage source to a heating element with which the bulb can be heated, and to a thermostatic expansion valve therefor.