The scheme of automatic control of the filling of the evaporator of the refrigeration machine
(57) Abstract:Usage: in automatic feed systems, evaporators, maintain, control and protection of vessels and equipment in refrigeration capacity from 100 000 kcal/h and above, mainly for ammonia get cold. The inventive scheme of automatic control of the filling of the evaporator of the refrigerating machine includes an evaporator with balancing column or other vessel containing a vapor-liquid phase refrigerant, the level Converter, gear and actuator. The Converter is made in the form of a thermometric valve associated pulse tube with a bulb mounted on the balance column at the height of a given level of refrigerant in the evaporator. The transmission mechanism includes a supply line of the diaphragm mechanism regulating valve with compressed air and work the valve thermostatic expansion valve installed on the discharge of compressed air from the membrane of the cavity of the valve. As the Executive body of the submission of the refrigerant in the evaporator is regulating the pneumatic valve. 1 Il. The invention relates to refrigeration, and bol is about to maintain and alarm preset level in vessels and apparatus, containing the boiling refrigerant and the suction compressors.The objective power of the evaporator is to regulate supply the optimal amount of refrigerant, providing the maximum possible removal of heat from the cooled object when guaranteeing trouble-free operation of the compressor. The complexity of the solution in this case is that it is necessary to combine two contradictions. On the one hand, to make the compressor run "dry-running", and on the other to ensure good filling of the evaporator with the refrigerant. The first requirement is necessary for the safe operation of the compressor, the second for the heat transfer rate.Currently, the primary use of have a system based on determining the amount of superheat of the refrigerant at the evaporator outlet or measuring the level of liquid refrigerant in the evaporator.Automatic feeding system evaporator overheat pair consists of a thermostatic expansion valve (TEV), the bulb that is installed on the outlet of the evaporator. The bulb is connected with a thermostatic expansion valve capillary tube.Thermostatic expansion valve membrane includes a box with a membrane and a throttling valve with actuator and mounting mechanism. Ter the left gauge thermosysteme, which converts the output of the temperature in the pressure. In a limited range can be considered as the pressure change is proportional to the temperature change. The more steam superheat, the higher the pressure in adminpanel cavity. It forces you to move the diaphragm downward and open the valve, the refrigerant enters the evaporator. When reducing the superheat valve is closed. Under the temperature of superheat refers to the difference between the temperatures of the refrigerant at the outlet of the evaporator and the boiling point.This system of regulation of the filling of the evaporator is very versatile and has a wide distribution, but bandwidth TEV has a limit, reaching which, it no longer increases with further increase in temperature, therefore, the application schema by using thermostatic expansion valve is limited by the cooling capacity of not more than 500 kW (see "Refrigeration technology", 7.8.92, S. 22-24).For evaporators high-capacity circuits automatically populate evaporators and level detection preferential spread regulators and transmitters float converters. In General, this circuit consists of a primary Converter, transmitting ele is ectronic block. The regulatory body may be a solenoid valve.The sensitive element of the float sensor is a steel hollow float is placed inside the camera sensor, which is in communication with the controlled vessel. Converting the level into an electrical signal by using inductors. When changing the level of the float enters the magnetic field of the coil. Due to this change in inductive reactance of the coils that is used to control the actuators. This scheme is selected as the closest analogue of the proposed solution.The disadvantage of the devices of the float type is the instability of the operation of the sensors due to accumulation of oil. So at least once in 10 days should be warming up and blowing devices, and drain oil. This raises the need to work in manual mode, and this can lead to technological violations.A well-developed system of relay-contact actuators entails the need for constant monitoring of her condition (see B. P. Akharov, I. C. Smirnov. Reference mechanic and refrigeration installations. L. Agropromizdat, 1989, S. Aly level Converter, electronic gear with electromagnetic Executive body, the proposed system as a level Converter contains gauge thermosysteme, consisting of the bulb of thermostatic expansion valve and capillary tube, uniting namebrand space TEV with the bulb. The transmission mechanism includes a diaphragm actuator control valve with air line and service valve thermostatic expansion valve, throttling the air at the outlet of the membrane boxes regulating valve, and as a regulator on the supply line of the refrigerant in the evaporator is installed control valve with diaphragm actuator.In this case, the income amount of refrigerant in the evaporator provides a pneumatic valve with diaphragm actuator, which in comparison with valve thermostatic expansion valve has virtually no limited bandwidth. The degree of filling of the evaporator is determined as a function of state termobarometricheskim system in contact with the vapor-gas phase.The drawing shows the scheme of automatic control of the filling of the evaporator of the refrigeration machine.The schema contains: 3 bulb 4. Balance column 1 through valves 5, 6, top-bottom, connected to the evaporator. The bulb 4 capillary tube 7 is connected with namebrands cavity 8 of thermostatic expansion valve (TEV) 9, 10 main pipeline compressed air line 11 for supplying air into the diaphragm cavity 12 of the regulating valve 13, 14 operating valve thermostatic expansion valve regulating the air outlet of the membrane cavity 12 of the regulating valve 13, valve 15 air sampling on the main pipeline 16 air filter, 17 - reducing valve 18 safety valve, 19, 20, 21 levels of Assembly connecting the bulb height of the evaporator, respectively, not less than 50% strictly 80% and 100%
The scheme works as follows.Balance column 1 and the evaporator 2 communicating vessels. The temperature of the liquid refrigerant are the same, the temperature of the gaseous refrigerant is different. So, in working with the load, the evaporator temperature of the liquid and gas up to suchoparek almost identical, and in the balance column for the mirror surface of the liquid phase vertically upwards there is a small pillar of the order of 40 to 60 mm liquid-vapor-gas phase changes greatly with temperature towards its improvement and next is mperature, 5 to 10ogreater than the boiling temperature in the apparatus. Therefore TEV works on contact with the vapor-gas phase or close to it, but not on superheat.For example, in the case of complete absence of the refrigerant in the evaporator bulb 4 adopts the temperature of its surroundings, and this corresponds to the maximum pressure on the membrane thermostatic expansion valve 9, which in this case will open the service valve thermostatic expansion valve 14. Line 11 is open to free air flow. The pressure in the diaphragm cavity 12 of the regulating valve 18 is missing. Regulating the pneumatic valve is fully open for admission of refrigerant into the evaporator.Upon receipt of the refrigerant temperature in the evaporator 2 and, respectively, in the balance column 1 is reduced. The pressure in the system: the bulb 4, the capillary tube 7, namebrand cavity 8 TEV is reduced, resulting in a working valve thermostatic expansion valve 14 begins to close, creating resistance at the air outlet of the membrane cavity 12 of the regulating valve 13. The pressure in line 11 is increased, the membrane valve moves the valve 13 to close. On filling of the evaporator 2 to the maximum level (typically 80% item 20), the liquid refrigerant comes into contact with tarmac the minimum value, working valve 14 will completely block the air vent of the membrane cavity 12, the pressure in the diaphragm cavity takes the maximum value, and regulating the pneumatic valve 13 will block the flow of refrigerant into the evaporator. As the suction of the refrigerant from the evaporator in the further course of the process level in the evaporator is reduced, the temperature of the bulb increases, which leads to the opening of the valve 14 TEV, which in turn will reset the air pressure in the line 11. The pressure in the diaphragm cavity regulating valve 13 drops, the valve opens again, allowing the flow of refrigerant into the evaporator.With a steady heat gain scheme regulates itself in the smooth flow of the refrigerant in the evaporator by means of the regulating valve.The use of a scheme of automatic control of the filling of the evaporators of refrigerating machines ensures reliable operation of the power system evaporator, expands the scope of a proportional regulator overheating, allows the use of EWM control schemes in high-performance ammonia plants. The scheme of automatic control of the filling of the evaporator refrigerating machines, containing an evaporator unabatedly mechanism and an Executive body, to ensure the delivery of refrigerant to the evaporator, characterized in that the Converter is made in the form termobarometricheskim system consisting of namebrands cavity expansion valve associated pulse tube with a bulb mounted on the balance column at the height of a given level of refrigerant in the evaporator, and the transmission mechanism includes a supply line of the diaphragm mechanism regulating valve with compressed air and work the valve thermostatic expansion valve installed on the discharge of compressed air from the membrane of the cavity of the pneumatic valve, and as the Executive of the refrigerant in the evaporator is regulating the pneumatic valve.
FIELD: mechanical engineering.
SUBSTANCE: wire-tubular evaporator is provided with guide plate whose body is extended lengthwise and at least one tubular clip for securing the plate to evaporator tube. Tubular clip is mounted on bracket extending aside from plate body.
EFFECT: enhanced accuracy of fitting the guide plate along center line of evaporator.
8 cl, 3 dwg
FIELD: cooling and air conditioning system components, particularly evaporators.
SUBSTANCE: evaporator comprises of the first elongated flat multi-channel pipe having serpentine configuration defined by elbow members bent across the minor dimension thereof. The pipe has a number of spaced apart parallel parts extending between ends of the first pipe. Inlet member of clamping means is connected to the first pipe end, outlet member thereof is fastened to the second end thereof. Ribs are located between neighboring parts of the first pipe. The second elongated flat multi-channel pipe forms suction radiator loop. The second pipe is connected to the first one so that side wall of the second pipe defining major pipe dimension is connected to side wall of the first pipe directly upstream of the outlet member of the clamping means to provide improved heat exchange between the pipes. The second pipe ends are also fitted with inlet and outlet members of clamping means.
EFFECT: increased compactness.
20 cl, 8 dwg
FIELD: refrigeration equipment.
SUBSTANCE: cooling agent evaporator comprises cooling agent pipeline and surface connected to the pipeline through heat-conductive connection. The surface is used as heat-exchanger and is covered with water-repellent oil film. The evaporator may be of lamella type (plate type).
EFFECT: decreased noise during evaporator operation.
3 cl, 1 dwg
FIELD: cooling equipment and other industry, for instance, chemical industry.
SUBSTANCE: evaporator comprises panels or coil pipe batteries, as well as liquid and vapor manifolds with coolant. Panels or coil pipe batteries or manifold batteries extend in horizontal direction one under another and are shifted one from another. The panels or coil pipe batteries or manifold batteries are enclosed with iron sheet having varying height. Panels or coil pipe batteries or manifold batteries are inserted in metal frame fixedly connected with metal tray and hermetically closed with plastic sheets along perimeter thereof.
EFFECT: provision of necessary heat carrier temperature and continuous temperature maintenance, decreased power inputs and heat carrier volume, reduced device costs and increased safety.
1 cl, 1 dwg
SUBSTANCE: milk refrigerating unit contains square reservoir with external heat-insulating coating, evaporator, force-suction manifold of compressor-condenser device. Evaporator is of slot type and represents two halves of V-shaped bottom with injector and suction header each, which are connected accordingly with force and suction manifolds of compressor-condenser device, at that slot evaporator is made with seam welding with seam width of at least 4 mm, pitch of seams of not more than 35 mm, depth rolling of slots of not more than 3 mm.
EFFECT: exclusion of evaporator damage during its flushing with hot water.
SUBSTANCE: invention relates to refrigerating equipment used in climate tests. The proposed heat exchanger comprises a housing and evaporator. The heat exchanger housing is separated by the main baffle into inlet and outlet chambers. The inlet chamber inlet accommodates deflecting baffle. The outlet chamber outlet accommodates the outlet pipe-bend and houses the evaporator and additional baffle. The inlet and outlet chambers communicate via a gap arranged between the main baffle and heat exchanger housing. The fan is arranged between the inlet pipe-bend and the housing. The bypass is provided for between the inlet and outlet pipe-bends.
EFFECT: longer faultless operation of evaporator.
2 cl, 1 dwg
FIELD: personal demand items.
SUBSTANCE: refrigerator with a freezing chamber includes a through internal container with a freezing chamber and a storage compartment for cooled products, which are rigidly connected to each other. There is no connection line or broken edge, at that, evaporator (9) is installed on compartment (6) of the freezing chamber. Evaporator is made in the form of a box with winding, which envelopes the freezing chamber in a circumferential direction on its four sides.
EFFECT: providing more effective cooling of products.
8 cl, 3 dwg
FIELD: heating systems.
SUBSTANCE: anti-frost evaporation tube of refrigerator with drawers consists of internal housing wherein there provided is food storage compartment for arranging drawer-container, and in the latter, low temperature is maintained by means of evaporation tube for cooling agent circulation, which is located around external part of internal housing. Evaporation tube includes curved parts located on both side surfaces of internal housing and straight tube part located on upper surface of internal housing and connected to curved tube parts.
EFFECT: use of this invention allows eliminating frost formation on roof surface of refrigerator internal housing.
5 cl, 7 dwg
FIELD: heating systems.
SUBSTANCE: invention refers to cryogenic equipment, and namely to cryogenic liquid evaporators, and can be used in gasification plants. Cryogenic liquid evaporator includes housing with cryogenic liquid supplying assembly and cooling agent output assembly and heat exchange assembly made in the form of a tube bank, inter-tube space of which includes dump packing. In addition, heat exchange assembly is equipped with gas distributing grid located in lower part of tube bank and having the shape of flattened cone installed with smaller base upwards. Dump packing is located on gas distributing grid.
EFFECT: use of invention will allow more efficient use of thermal and physical properties of heat exchange assembly of cryogenic liquid evaporator owing to arrangement of dump packing with section having constant resistance, and creating conditions of uniform distribution and passing of warm gas vapours through the head piece.
SUBSTANCE: invention concerns refrigerating engineering. A heat exchanger (301) is designed to be connected to an evaporator (201) of a heat-transfer system wherein a working medium used is compressed and evaporated. The heat exchanger comprises a first tube (107) with its first end (303) shaped in such a way to be attached to an outlet fitting (204) of the evaporator and to transfer the medium from said outlet fitting, and the second tube (108) with its first shaped in such a way to be connected to the inlet fitting of the evaporator and to transfer the medium to said inlet fitting. The second tube is mounted inside of the first tube, or in thermal contact thereto, herewith ensuring the relations (109, 110) of the respective lengths of the first and second tubes to enable heat exchange between the mediums in these tubes. The first tube is made of the steel alloy consisting of ingredients reducing hardness of said steel alloy, thereby easing bend of the tube and enabling to bend the first tube in installation in the heat transfer system.
EFFECT: application of the invention allows reducing cost of the heat exchanger.
31 cl, 10 dwg
FIELD: cooling engineering.
SUBSTANCE: device comprises two temperature gauges, unit for comparing temperatures, unit for generating alarm signal on wet stroke, converters for converting signals from temperature gauges into the alternating signals, frequency synchronizer, amplifier, and protecting relay. The first temperature gauge is set in the line for supplying coolant to the object to be cooled. The second temperature gauge is set at the inlet of the line for withdrawing the vapors of coolant from the object to be cooled to the bridge of switching of the compressors. The converters are synchronized in frequency. The unit for comparing temperatures is made of a transformer with magnetization and two primary windings which are connected in series with the signal converters. The secondary winding is connected with the input of the amplifier whose output is provided with the protecting relay.
EFFECT: enhanced reliability.
FIELD: mechanical engineering, particularly devices to prevent wet vapor ingress in cylinders of compressors used in gas-processing plants for pressure increase in natural gas pipelines.
SUBSTANCE: device comprises horizontal sucking pipe and emergency shutdown sensor. Low-frequency ultrasound generator is arranged inside horizontal sucking pipe. Ultra-violet radiation sensor is installed in lower part of horizontal sucking pipe and is spaced 0.1-1 m from low-frequency ultrasound generator.
EFFECT: increased operational reliability.
FIELD: conditioning system, particularly ones adapted for vehicle conditioning and provided with centrifugal compressors.
SUBSTANCE: cooling plant comprises closed loop with sealed centrifugal pump with built-in electric motor, as well as condenser with axial fan, thermostatic expansion valve and evaporator. Thermal phial of thermostatic expansion valve is installed at evaporator outlet. Bypass line with throttle is connected in parallel to thermostatic expansion valve. Object to be conditioned is communicated to evaporator through air loop provided with centrifugal fan. Throttle has locking valve and bellows-type pneumatic drive having control cavity communicated with thermal phial of thermostatic expansion valve.
EFFECT: simplified structure and increased operational reliability.
FIELD: refrigerating engineering.
SUBSTANCE: refrigerating plant comprises vessels and metallic pads that underlie the vessels and are connected to the pipeline through branch pipes. The pipeline is mounted with an inclination and is connected with the pressure-tight tank for collecting spilled ammonia. The tank is connected with the atmosphere through the pipeline and stop valve and is provided with air separator for removing air from its steam zone, branch pipes, and pipeline.
EFFECT: enhanced efficiency.
3 cl, 1 dwg
FIELD: lighting; heating.
SUBSTANCE: invention proposes a method for controlling operation of a refrigerator compressor whereby thawing is effected when the temperature inside the refrigerator reaches a predetermined thawing temperature. Refrigerating capacity of the compressor mounted inside the refrigerator is changed depending on the temperature inside the refrigerator by regulating the direction of rotation of the compressor. The refrigerating capacity of the compressor is increased by rotating the compressor in one direction and is decreased by rotating the compressor in another direction, this second direction being reverse to the first one. Prior to thawing the compressor is repeatedly rotated in the second direction and stopped until the predetermined thawing temperature is achieved inside the refrigerator. After thawing the compressor is rotated in the first direction until the predetermined temperature is achieved and in order to maintain this predetermined temperature the compressor is periodically stopped or rotated in the second direction. A device for controlling operation of a refrigerator compressor includes a microcomputer, a working frequency converter, a rotation signal generating unit and a unit for measuring temperature inside the refrigerator. The working range of the temperature measuring unit is predetermined depending on the compressor rotation direction.
EFFECT: reduced power consumption by a refrigerator; increased capacity and precise temperature control of the refrigerator.