CN112484351A - Large-span low-temperature refrigerating system for test box - Google Patents
Large-span low-temperature refrigerating system for test box Download PDFInfo
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- CN112484351A CN112484351A CN202011395732.7A CN202011395732A CN112484351A CN 112484351 A CN112484351 A CN 112484351A CN 202011395732 A CN202011395732 A CN 202011395732A CN 112484351 A CN112484351 A CN 112484351A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B39/00—Evaporators; Condensers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
- F25B43/02—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat for separating lubricants from the refrigerant
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
- F25B49/022—Compressor control arrangements
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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Abstract
The invention discloses a large-span low-temperature refrigerating system for a test box, which comprises a high-temperature-level unit, a low-temperature-level unit and a cold-carrying unit which are in cascade refrigeration, and cooling water circulation assemblies which are communicated with the high-temperature-level unit, the low-temperature-level unit and the cold-carrying unit; the condensing evaporator is arranged between the high-temperature-stage unit and the low-temperature-stage unit, the medium-temperature-stage evaporator is arranged between the cold carrying unit and the high-temperature-stage unit, the D evaporator is arranged between the cold carrying unit and the low-temperature-stage unit, the high-temperature-stage unit comprises N G compressors connected in parallel, and N compressors connected in parallelThe suction end of the G compressor is communicated with the G suction manifold, the exhaust end is communicated with the G exhaust manifold, and N is in front1Stage and back N2A G suction manifold and a G exhaust manifold between the G compressors are respectively provided with a through switch valve and a shunt three-way switch valve, wherein N is N1+N2And N is1≤N2And the angle valve side of the flow dividing three-way switch valve is communicated with the G suction manifold. It reduces the pressure ratio, improves the operation efficiency and the safety, and is beneficial to obtaining lower temperature.
Description
Technical Field
The invention relates to the technical field of special refrigeration, in particular to a large-span low-temperature refrigeration system for a test box.
Background
When a cold space is used for refrigeration, along with the wide range change of temperature, contradiction exists between the cold demand load and the refrigeration capacity of the refrigerating unit, the higher the temperature is, the smaller the space cold demand is, and the larger the refrigeration capacity of the specific refrigerating unit is; especially, a large-mass load experiment article and a large-mass cold (heat) storage material are often arranged in a plurality of large-volume low-temperature experiment spaces, the temperature reduction process has time limitation or speed requirement, so that relatively larger refrigerating output is needed in the temperature reduction stage, the cold storage load is basically reduced to zero in the temperature maintaining stage, and the refrigerating load requirement is reduced to be very small. In all the refrigeration occasions, the requirement that the refrigerating unit has good unloading capacity is mainly realized by connecting a plurality of units in parallel or frequency conversion units, under the current situation that the frequency conversion units are not generally applied in the application field of special refrigeration at present, if the number of compressors is too small, the load shedding capacity of the unit in the maintenance stage is weak, the temperature control precision is difficult to realize, and the energy consumption is obvious by adopting a heating balance mode for temperature control, so that the defects are more serious under the requirement of a large temperature difference cooling environment.
For the large temperature difference cooling refrigeration in the common refrigeration, no matter single-stage refrigeration or overlapping refrigeration, the compression ratio is larger when the compressor operates along with the lower box temperature, the efficiency of the compressor is reduced, and particularly when the single-unit pressure ratio exceeds more than 6, the efficiency is often generated in the operation of an actual refrigeration system. Therefore, the refrigeration system needs to increase the compression stages more advantageously, such as configuring the refrigeration system as two-stage compression cascade or three-stage cascade, but such fixed multi-stage refrigeration configuration can affect the refrigeration efficiency when the temperature of other temperature sections is reduced in the whole process of box temperature change.
Disclosure of Invention
The invention aims to solve the technical problem of providing a large-span low-temperature refrigeration system for a test chamber, which reduces the pressure ratio through reasonable structural design, improves the operation efficiency and safety and is beneficial to obtaining lower temperature; the natural cooling capacity is fully utilized in the cooling process, the high evaporation temperature of the refrigerating unit is always ensured, and the refrigerating efficiency of the unit is maintained at any time.
In order to solve the technical problem, the invention provides a large-span low-temperature refrigeration system for a test box, which comprises a high-temperature-level unit, a low-temperature-level unit, a cold-carrying unit and a cooling water circulation assembly, wherein the high-temperature-level unit, the low-temperature-level unit and the cold-carrying unit are overlapped and refrigerated, and the cooling water circulation assembly is communicated with the high-temperature-level unit; be provided with the condensation evaporimeter between high-temperature level unit and the low-temperature level unit, be provided with the medium temperature level evaporimeter between year cold machine group and the high-temperature level unit, be provided with the D evaporimeter between year cold machine group and the low-temperature level unit, the high-temperature level unit includes N parallelly connected G compressors, N the end of breathing in of G compressor all communicates in G collector of breathing in, and the exhaust end all communicates in G exhaust collector, N in the front N the collector that breathes in1Stage and back N2A G suction manifold and a G exhaust manifold between the G compressors are respectively provided with a through switch valve and a shunt three-way switch valve, wherein N is N1+N2And N is1≤N2And the angle valve side of the flow dividing three-way switch valve is communicated with the G suction manifold.
In a preferred embodiment of the invention, the G compressor is further provided with a G oil return pipe and a G liquid spray pipe, the G oil return pipe is provided with an electromagnetic valve, each G oil return pipe is connected out from a G oil return header and communicated to a G oil separator, the G oil separator is communicated with a G oil cooler, and an oil constant temperature valve is arranged on an oil return pipeline connected with the G oil cooler; and the G liquid spraying pipes of the G compressor are all provided with liquid spraying pipeline electromagnetic valves, and each G liquid spraying pipe is connected with a liquid inlet pipe of a supercooling side pipeline of the G economizer.
In a preferred embodiment of the present invention, the gas-liquid separator further comprises a gas-liquid separator connected to the gas-liquid separator; and an evaporation side gas return pipe of the G economizer is connected to a G gas suction header.
In a preferred embodiment of the invention, the outlet pipe of the G oil separator is connected to the inlet of a G condenser, the outlet of the G condenser is divided into two pipelines after passing through an electromagnetic valve and is respectively connected to pipe orifices on two sides of an evaporation side and a supercooling side of the G economizer, the pipeline on the evaporation side is provided with the electromagnetic valve and a temperature control expansion valve, and the outlet of the G economizer is connected to a G suction manifold; and the supercooling side inlet pipeline of the G economizer is respectively connected with three pipelines, and the three pipelines are respectively connected with G liquid spraying pipes of the G compressors through G liquid spraying pipes where liquid spraying pipe electromagnetic valves are located.
In a preferred embodiment of the present invention, the number of the G compressors is 2 to 5.
In a preferred embodiment of the present invention, the direct-flow switch valve and the three-way shunt switch valve are electric valves with associated electric actions, when the direct-flow switch valve is closed and the three-way shunt switch valve is simultaneously turned on, the high-temperature stage unit formed by N parallel-connected G compressors is switched to a two-stage compressor unit, where N is2The platform parallel G compressors form a low-pressure stage unit of the two-stage unit, N1The parallel G compressors form a high-pressure stage unit of the double-stage unit.
In a preferred embodiment of the present invention, the low temperature stage unit further includes M D compressors, exhaust ends of the M D compressors are all communicated with a D exhaust manifold, suction ends are all communicated with a D suction manifold, an oil return end is communicated with a D oil return manifold after passing through an electromagnetic valve, the D oil return manifold is communicated with a D oil separator, the D oil separator is communicated with a D oil cooler, and an oil return pipeline connected to the D oil cooler is provided with an oil thermostatic valve; the D air suction manifold is connected with the D evaporator; and the D exhaust manifold is connected to the D oil separator through a D exhaust manifold.
In a preferred embodiment of the invention, the oil separator further comprises a working medium side inlet of a D precooler connected with an outlet pipe of the D oil separator, the working medium side outlet of the D precooler is connected with a working medium side inlet of a condensation evaporator, the working medium side outlet pipe of the condensation evaporator is divided into two pipelines after passing through an electromagnetic valve, the two pipelines are respectively connected into pipe orifices on two sides of an evaporation side and a supercooling side of the D economizer, the pipeline on the evaporation side is provided with the electromagnetic valve and a throttle valve, and the outlet of the D economizer is connected into an economizer interface of a D compressor through a return air pipe of the D economizer and is controlled by the electromagnetic valve to be switched on and.
In a preferred embodiment of the invention, the low-temperature stage unit further comprises a low-pressure expansion tank, and an expansion tank main pipe of the low-pressure expansion tank is connected with a D suction manifold; the D pressure relief pipe of the low-pressure expansion tank is connected with the D exhaust manifold; and an oil return pipe of the low-pressure expansion tank is connected with an oil return header D.
In a preferred embodiment of the invention, the cold carrying unit further comprises a cold carrying solution tank, a solution pump, a D evaporator, a medium-temperature-stage evaporator, a high-temperature-stage heat exchanger, a tail end heat exchanger assembly, a temperature regulation control valve, an electric switch valve, an electromagnetic valve, a check valve and a check valve, wherein the solution pump is provided with L groups connected in parallel, the outlet of each solution pump is provided with the check valve, the inlet of each solution pump is used for taking liquid from the cold carrying solution tank, the outlet of each solution pump is finally converged to a main pipe, the main pipe is respectively connected with the D evaporator, the medium-temperature-stage evaporator and the high-temperature-stage heat exchanger, the pipelines are controlled to be on and off through the electric switch valve, and liquid outlet pipelines of the D evaporator, the medium-temperature-stage evaporator and the high-temperature-stage heat exchanger are converged to a.
The invention has the beneficial effects that:
according to the large-span low-temperature refrigeration system for the test box, through optimized design, in the high-temperature stage of the cooling stage, all G compressors can work in a parallel connection mode, the requirement on cooling capacity can be met only by opening one of the G compressors when the higher box temperature is started, and the number of the opened G compressors is gradually increased along with the reduction of the box temperature until all the units connected in parallel are fully opened, so that the size configuration of components of the refrigeration system is reduced, and high-efficiency operation and energy conservation are realized; and when the temperature of the test box is reduced to be below a certain temperature, the state of the G compressor which originally works in parallel is changed into the following state through the combined action of the shunt three-way switch valve and the through switch valve: one part of the G compressors is still in a parallel state and becomes a low-temperature stage of the double-stage unit, the other part of the G compressors in parallel connection is switched to a high-temperature stage of the double-stage unit, and the two parts of the G compressors form a serial state, so that the high-temperature stage unit integrally operates according to the double-stage unit, and the high pressure ratio of the unit operation is avoided. When the temperature of the box is continuously reduced, all the units operate in an integral overlapping mode, so that the defect that the configuration capacity of the compressor cannot be exerted due to overlarge specific volume during the refrigerating operation of the single high-temperature working medium is overcome; even if the compressor unit operates in a cascade mode, the system can still realize the single-stage and double-stage switching of the high-temperature-stage unit, and prevent the high-pressure-ratio operation of each stage of compressor unit as much as possible. The defects of large unit size, high manufacturing cost and large power distribution caused by overlarge refrigerating capacity and huge configuration under high-temperature working conditions during unit configuration are avoided, and the high efficiency of the unit is ensured; meanwhile, the defects of large operation pressure ratio, low efficiency and unsafe operation of all levels of units of the conventional design system of the whole system under the large-span low-temperature working condition are overcome, and the safe operation of the units is ensured. The pressure ratio is reduced, so that the clearance loss of the compressor during the refrigeration operation is reduced, and the operation efficiency of the compressor is improved; but also is beneficial to obtaining lower temperature; the natural cooling capacity is fully utilized in the cooling process, the high evaporation temperature of the refrigerating unit is always ensured, and the refrigerating efficiency of the unit is maintained at any time. The system is suitable for the overlapping refrigeration occasions with the temperature range from normal temperature to below-60 ℃ in the box body, and is particularly suitable for the occasions with variable temperature requirements.
Drawings
FIG. 1 is a schematic diagram of the overall structure of a large-span cryogenic refrigeration system for a test chamber in a preferred embodiment of the present invention;
FIG. 2 is a schematic diagram of the structure of the cascade refrigeration unit low-temperature stage unit in the large-span low-temperature refrigeration system for the test box in the preferred embodiment of the invention;
FIG. 3 is a schematic structural diagram of a cascade refrigeration unit high temperature stage unit in a large span low temperature refrigeration system for a test box in a preferred embodiment of the invention;
fig. 4 is a schematic structural diagram of a refrigerating unit in a large-span cryogenic refrigeration system for a test chamber according to a preferred embodiment of the present invention.
The reference numbers in the figures illustrate:
1: low-temperature-stage unit, 2: high-temperature-stage unit, 3: cold-carrying unit, 4: cooling water circulation integration, 11: cooling water outlet header pipe, 12: cooling water inlet manifold, 13: oil cooler, 14: d precooler, 15: d evaporator, 21: oil cooler, 22: g condenser, 23: intermediate-temperature stage evaporator, 24: condenser evaporator, 31: high-temperature-stage heat exchanger.
101: low-pressure expansion tank, 102: compressor, 103: d relief valve, 104: d pressure relief tube, 105: d suction manifold, 106: d suction pipe, 107: d exhaust manifold, 108: d-oil separator, 109: cooling water low temperature level unit water supply inlet tube, 110: cooling water low temperature level unit water supply wet return, 111: oil return pipe D, 113: d oil-cooled cooling water inlet and outlet pipe, 114: d precooler cooling water inlet and outlet pipe, 116: solenoid valves a, 117: solenoid valves b, 118: throttle valves a, 120: throttle valve b, 121: d evaporator return pipe, 122: d economizer, 123: d economizer return pipe, 124: solenoid valve c, 125: d return oil header, 126: d exhaust manifold, 127: d exhaust pipe, 128: check valve, 129: solenoid valve d, 130: d oil return pipe, 131: low pressure expansion tank return line, 132: expansion tank main pipe, 133: and an oil return valve.
201: g compressor, 202: g suction pipe, 203: g suction manifold, 204: g liquid spraying pipe, 205: g economizer return pipe, 206: through switch valve, 207: shunt three-way switching valve, 208: g gas branch return gas manifold, 209: g gas-liquid separator, 210: cooling water high-temperature stage unit water supply inlet tube, 211: cooling water high-temperature unit water supply return pipe, 212: g exhaust manifold, 213: g return air manifold, 214: g oil separator, 216: oil G return pipe, 217: g oil-cooled cooling water inlet and outlet pipe, 218: g condenser cooling water inlet and outlet pipe, 220: electromagnetic valves aa, 221: liquid ejection line solenoid valve, 222: electromagnetic valve bb, 223: thermostatic expansion valve, 224: g economizer, 225: g economizer sub-cooling feed line, 226: solenoid valve cc, 227: throttle valves aa, 229: solenoid valve dd, 230: throttle bb, 232: g return oil header, 233: g exhaust manifold, 234: g exhaust pipe, 235: check valves aa, 236 solenoid valves ee, 237: g an oil return pipe.
301: cold-carrying solution tank, 302: solution pump, 304: check valve aaa, 306: high-temperature stage heat exchanger solution circulation pipe, 308: end supply header, 309: end heat exchanger integration, 310: end heat exchanger solution circulation pipe, 311: temperature adjustment control valve, 312: solenoid valves aaa, 313: end return manifold, 314: terminal solution return pipe, 315: electric switch valve, 316: a check valve bbb.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.
Examples
The invention discloses a large-span low-temperature refrigerating system for a test box, which is shown by referring to fig. 1-4 and comprises a high-temperature-level unit 2, a low-temperature-level unit 1, a cold-carrying unit 3 and a cooling water circulation assembly 4 which are communicated with the high-temperature-level unit, the low-temperature-level unit and the cold-carrying unit. A condensing evaporator 24 is arranged between the high-temperature-stage unit 2 and the low-temperature-stage unit 1. An intermediate-temperature-stage evaporator 23 is arranged between the cold-carrying unit 3 and the high-temperature-stage unit 2. And a D evaporator 15 is arranged between the cold carrying unit 3 and the low-temperature-level unit 1. The high temperature stage train 2 includes N G compressors 201 connected in parallel. The suction ends of the N G compressors 201 are all communicated with the G suction manifold 203, and the exhaust ends are all communicated with the G exhaust manifold 233. Preceding N1Stage and back N2 A G suction manifold 203 and a G exhaust manifold 233 between the G compressors 201 are respectively provided with a through switch valve 206 and a shunt three-way switch valve 207, wherein N is N1+N2And N is1≤N2. The angle valve side of the three-way flow dividing switching valve 207 is connected to the G suction manifold 203. In the optimized design, the high-temperature-level unit 2 and the low-temperature-level unit 1 are mainly connected through the condensing evaporator 24, and the low-temperature-level unit is in cascade refrigeration operationThe condensation heat of the condenser 1 is exchanged with the refrigerating capacity generated by the high-temperature-stage unit 2 through a condensation evaporator 24; the cold-carrying unit 3 is mainly linked with the high-temperature unit 2 through the medium-temperature evaporator 23, and the circulating coolant of the cold-carrying unit 3 can be cooled by the medium-temperature evaporator 23 as required; the cold-carrying unit 3 is mainly linked with the low-temperature-level unit 1 through the D evaporator 15, and the circulating secondary refrigerant of the cold-carrying unit 3 can be sent to the D evaporator 15 to be cooled by the D evaporator 15 as required; the cooling water circulation assembly 4 can provide cooling water for the high-temperature-stage unit 2, the low-temperature-stage unit 1 and the cold carrier unit 3. The N G compressors 201 in the high-temperature stage unit 2 can realize the full parallel connection or the overall series connection of the G compressors 201 as required through the straight-through switch valve 206 on the G suction header 203 and the shunt three-way switch valve 207 on the G exhaust header 233, the full parallel connection and the single-stage operation are realized when the temperature of the tank is slightly higher, and the overall series connection and the double-stage operation are realized when the temperature of the tank is slightly lower. The specific implementation process is that at the high temperature stage of the cooling stage, each G compressor 201 can work in a parallel connection mode, only one of the G compressors needs to be started to meet the requirement of cooling capacity when the higher tank temperature is started, and the number of the started G compressors is gradually increased along with the reduction of the tank temperature until each set connected in parallel is fully started, so that the size configuration of components of the refrigeration system is reduced, the high-efficiency operation is realized, and the energy is saved; when the temperature of the test box is reduced to be lower than a certain temperature, the state of the G compressor 201 which originally works in parallel is changed into that by the combined action of the three-way shunt switch valve 207 and the three-way through switch valve 206: one part of the G compressors 201 are still in parallel connection and become the low-temperature stage of the double-stage unit, the other part of the G compressors 201 in parallel connection is switched to the high-temperature stage of the double-stage unit, and the two parts of the G compressors 201 form a serial connection state, so that the high-temperature stage unit 2 integrally operates according to the double-stage unit, and the high pressure ratio of the unit operation is avoided. When the temperature of the box is continuously reduced, all the units operate in an integral overlapping mode, so that the defect that the configuration capacity of the compressor cannot be exerted due to overlarge specific volume during the refrigerating operation of the single high-temperature working medium is overcome; even if the compressor operates in a cascade mode, the system can still realize the single-stage and double-stage switching of the high-temperature stage unit 2, and prevent the large-pressure-ratio operation of each stage of compressor unit as much as possible. Thereby avoiding high temperature working in single unit configurationThe defects of large unit size, high manufacturing cost and large power distribution caused by large configuration due to overlarge refrigerating capacity are overcome, and the high efficiency of the unit is ensured; meanwhile, the defects of large operation pressure ratio, low efficiency and unsafe operation of all levels of units of the conventional design system of the whole system under the large-span low-temperature working condition are overcome, and the safe operation of the units is ensured. The pressure ratio is reduced, so that the clearance loss of the compressor during the refrigeration operation is reduced, and the operation efficiency of the compressor is improved; but also is beneficial to obtaining lower temperature; the natural cooling capacity is fully utilized in the cooling process, the high evaporation temperature of the refrigerating unit is always ensured, and the refrigerating efficiency of the unit is maintained at any time. The system is suitable for the overlapping refrigeration occasions with the temperature range from normal temperature to below-60 ℃ in the box body, and is particularly suitable for the occasions with variable temperature requirements.
The number of the G compressors 201 is two to five. Preferably three.
Specifically, the high-temperature stage unit 2 further includes a G oil separator 214, a G oil cooler 21, a G gas-liquid separator 209, a G economizer 224, a G condenser 22, solenoid valves aa220, bb222, cc226, dd229, ee236, a temperature-controlled expansion valve 223, throttle valves aa227, bb230, a check valve aa235, a condenser evaporator 24, a medium-temperature stage evaporator 23, and a connecting pipe.
The G suction manifold 203 is provided with a through switch valve 206, and the G suction manifold 203 is connected with a G gas-liquid separator 209 through a G gas-liquid separation return gas manifold 208; a three-way diverter switch valve 207 is arranged on the G exhaust manifold 232, and the angle valve side of the three-way diverter switch valve 207 is connected to the G suction manifold 203; the evaporation side return air pipe of the G economizer 224 is connected to the G suction header 203.
An outlet pipe of the G oil separator 214 is connected to an inlet of the G condenser 22, an outlet of the G condenser 22 is divided into two pipelines after passing through an electromagnetic valve aa220 and is respectively connected to pipe orifices on two sides of an evaporation side and a supercooling side of the G economizer 224, wherein the pipeline on the evaporation side is provided with an electromagnetic valve bb222 and a temperature control type expansion valve 223, the electromagnetic valve bb and the temperature control type expansion valve are evaporated and gasified by passing through the G economizer 224, and the outlet of the electromagnetic valve bb is connected to a G suction manifold 203 by passing through a G economizer air return; the supercooling side inlet pipeline of the G economizer 224 is connected with three pipelines respectively, and the three pipelines are connected with the liquid spraying ports of the G compressors 201 through G liquid spraying pipes 204 where liquid spraying pipe electromagnetic valves 221 are located. Cycle fluid enters the G-economizer 224 from the subcooling side inlet header of the G-economizer 224. The cycle fluid, after having been subcooled therein, may pass through solenoid valve cc226 and throttle valve aa227, respectively, in sequence, via G economizer sub-cooling supply line 225. The circulating working medium is subjected to on-off control by a solenoid valve cc226 or enters the condensation evaporator 24 to provide cold energy for the low-temperature unit 1 as required, and at the moment, the circulating working medium is overheated after the condensation evaporator 24 absorbs heat and then flows back to the G gas-liquid separator 209 through the G gas return header pipe 213; or the circulating working medium enters the intermediate-temperature-stage evaporator 23 to cool the circulating cooling medium of the refrigerating unit 3, and the circulating working medium is overheated and flows back to the G gas-liquid separator 209 through the G gas return header pipe 213 after the intermediate-temperature-stage evaporator 23 absorbs heat; finally, the superheated gas enters the G suction manifold 203 through the G gas branch return manifold 208 and is drawn back by the G compressor 201.
In some preferred embodiments of the large-span low-temperature refrigeration system for the test chamber, taking three G compressors 201 as an example, in the high-temperature stage unit 2, the installation positions of the through switch valve 206 installed on the G suction header 203 and the shunt three-way switch valve 207 installed on the G exhaust header 233, and the connection positions of the relevant connection pipes are specified as follows: the three G compressors 201 which are originally in a parallel state are separated by the straight-through switch valve 206 and the shunt three-way switch valve 207, only two G compressors are continuously in a parallel state, and the other G compressor is in an independent state; the G suction manifold 203 of the G compressor 201 in this independent state is connected to the corner valve side of the three-way flow dividing switching valve 207; the G suction manifold 203 of the G compressor 201 in this independent state is also connected to the evaporation side muffler of the G economizer 224; the connection position of the G discharge header pipe 212 and the G discharge header pipe 233 is on the discharge side of the G compressor 201 in that independent state; the connection position of the G gas branch return header 208 and the G gas suction header 203 is located on the gas suction side of the two G compressors 201 still connected in parallel. When there are more than three G compressors 201, there may be more than two G compressors 201 in parallel, and there may be more than one G compressor 201 in independent state.
The through switch valve 206 and the shunt three-way switch valve 207 in the high-temperature stage unit 2 are electrically operated valves associated with electric operations. The working mode is as follows: when the straight-through switch valve 206 is in a straight-through opening state as required, the shunt three-way switch valve 207 is in a straight-through state at the same time, and the N G compressors 201 are connected in parallel; when the through switch valve 206 is in a closed state as required, the shunt three-way switch valve 207 is simultaneously in an angle-pass state, and at the moment, a high-temperature stage unit formed by N parallel G compressors 201 is switched into a two-stage compressor unit, wherein N is2The parallel G compressors 201 form the low-pressure stage unit of the two-stage unit, N1The stage-parallel G compressor 201 constitutes a high-pressure stage unit of the two-stage unit.
The low-temperature stage unit 1 includes M D compressors 102, a low-pressure expansion tank 101, a D relief valve 103, a D oil separator 108, a D evaporator 15, a D economizer 122, a D oil cooler 13, a condenser evaporator 24, solenoid valves a116, b117, c124, D129, throttle valves a118, b120, a check valve 128, and a connecting pipe. Preferably, M is 1 to 3. Wherein:
the D discharge pipe 127 of each of the D compressors 102 is provided with a check valve b 128. The D exhaust pipes 127 all converge to a D exhaust manifold 126; the D suction pipes 106 of each D compressor 102 are connected from a D suction header 105; the D oil return pipe 130 of each D compressor 102 is provided with an electromagnetic valve D129, the D oil return pipe 130 is connected out from a D oil return manifold 125, the D oil return manifold 125 originates from a D oil return pipe 111 from an outlet of the D oil separator 108, and cools lubricating oil through the D oil cooler 13, and an oil thermostatic valve is arranged on the oil return pipe connected with the D oil cooler 13; each D economizer return air pipe 123 is provided with an electromagnetic valve c 124. The D suction manifold 105 is connected with the D evaporator 15 through a D evaporator air return pipe 121; the D exhaust manifold 126 is connected to the D oil separator 108 via a D exhaust manifold 107.
An outlet pipe of the D oil separator 108 is connected to a working medium side inlet of the D precooler 14, a working medium side outlet of the D precooler 14 is connected to a working medium side inlet of the condensation evaporator 24, a working medium side outlet pipe of the condensation evaporator 24 is divided into two pipelines after passing through an electromagnetic valve a116, the two pipelines are respectively connected to two side pipe orifices of an evaporation side and a supercooling side of the D economizer 122, the evaporation side pipeline is provided with an electromagnetic valve b117 and a throttle valve a118, the two pipelines are evaporated and gasified by the D economizer 122, and the outlet is connected to an economizer interface of the D compressor 102 through a D economizer air return pipe 123 and is controlled by an electromagnetic valve c124 to be switched on and switched; and the circulating working medium enters the D economizer 122 from a supercooling side inlet header pipe of the D economizer 122, is supercooled in the circulating working medium and then enters the D evaporator 15 through the throttle valve b120 to provide cold energy for the circulating working medium of the refrigerating unit 3 as required, and at the moment, the circulating working medium is superheated and flows back to the D suction manifold 105 after the D evaporator 15 absorbs heat and is pumped back by the D compressor 102.
The low-pressure expansion tank 101 is connected to the other components of the low-temperature stage unit 1 by three lines: connected with the D suction manifold 105 through the expansion tank main pipe 132; the D pressure relief pipe 104 is connected with the D exhaust manifold 126, and the on-off state is controlled by the D pressure relief valve 103 on the pipeline; the low-pressure expansion tank oil return pipe 131 is connected with the D oil return collecting pipe 125, and the on-off is controlled by an oil return valve 133.
The cold carrier unit 3 comprises a cold carrier solution tank 301, a solution pump 302, a D evaporator 15, a medium-temperature stage evaporator 23, a high-temperature stage heat exchanger 31, a tail end heat exchanger assembly 309, a temperature regulation control valve 311, an electric switch valve 315, an electromagnetic valve aaa312, a check valve aaa304, a check valve bbb316 and a connecting pipe. Wherein:
the solution pump 302 has L groups connected in parallel. Preferably, L is 1 to 3 groups, each group can be provided with a plurality of solution pumps 302 which can be respectively connected in parallel for use or set for standby, and the solution pumps respectively bear the liquid supply circulation tasks at different temperature levels during refrigeration operation. The outlet of each solution pump 302 is provided with a check valve bbb316, and the inlet of each solution pump is used for taking liquid from the cold carrying solution tank 301. The outlet of the solution pump 302 is finally converged to a main pipe, and the main pipe is respectively connected with the D evaporator 15, the medium-temperature-stage evaporator 23 and the high-temperature-stage heat exchanger 31, and the on-off control of each pipeline is performed through an electric switch valve 315. Solution outlet pipelines of the heat exchangers are converged to a liquid supply header pipe 308 through check valves aaa304, sent to an inlet of a tail end heat exchanger assembly 309, and then pass through a tail end heat exchanger solution circulation pipe 310, so that the solution enters the tail end heat exchanger assembly 309 for heat exchange and then flows back to the cold-carrying solution tank 301 through a tail end liquid return header pipe 313. In order to control the amount of heat exchange in the end heat exchanger assembly 309, a temperature control valve 311 is installed between the solution inlet and outlet pipes of the end heat exchanger assembly 309. In order to facilitate the solution contained in the end heat exchanger assembly 309 to directly flow back to the cold-carrying solution tank 301 when necessary, an end solution return pipe 314 which flows back to the cold-carrying solution tank 301 is installed on the solution inlet pipeline of the end heat exchanger assembly 309, and the on-off of the pipeline is controlled by a solenoid valve aaa 312.
The cooling water circulation assembly 4 comprises a cooling tower, a circulating water pump, a connecting pipeline, a cooling water inlet header pipe 12, a cooling water outlet header pipe 11, a cooling water high-temperature-level unit water supply inlet pipe 210, a cooling water high-temperature-level unit water supply return pipe 211, a G oil-cooled cooling water inlet pipe 217, a G condenser cooling water inlet and outlet pipe 218, a cooling water low-temperature-level unit water supply inlet pipe 109, a cooling water low-temperature-level unit water supply return pipe 110, a D oil-cooled cooling water inlet and outlet pipe 113, a D precooler cooling water inlet and outlet pipe 114 and a high-temperature-level heat exchanger cooling water inlet and outlet pipe 306; the cooling water is cooled and driven by the cooling water circulation assembly 4, and is respectively sent to the G oil cooler 13, the G condenser 22, the D oil cooler 13, the D precooler 14 and the high-temperature-level heat exchanger 31 through cooling water supply and return pipelines, and after heat is released by each heat exchanger as required, the cooling water flows back to the cooling water and driving assembly 4 again for cooling, so that the cooling water circulates. Specifically, the cold carrier set 3 and the cooling water circulation assembly 4 can be connected through the high-temperature heat exchanger 31, and the high-temperature coolant of the cold carrier set 3 can be cooled by the cooling water in a relatively low-temperature state as required; when the high-temperature-stage unit 2 operates, the cooling water circulation assembly 4 respectively provides cooling water for the G oil cooler 21 and the G condenser 22 of the high-temperature-stage unit 2; when the low-temperature-level unit 1 operates, the cooling water circulation assembly 4 respectively provides cooling water for the D oil cooler 13 and the D precooler 14 of the low-temperature-level unit 1.
Although theoretically, the system uses 3 high-temperature stage compressors G and 2 low-temperature stage compressors D to explain the working principle of the embodiment of the present invention, in practice, 2 to 5 compressors may be used for the high-temperature stage to form a unit, and 1 to 3 compressors may be used for the low-temperature stage to form a low-temperature stage unit.
In the test box low-temperature refrigeration system, one or more G compressors 207 in a parallel state can be started as required whether the system operates in a single-stage state or a double-stage working state. If the system operates in a single stage, only 1 compressor is needed to be started under the highest temperature working condition, and as the evaporation temperature of the system is reduced and the demand for the refrigerating capacity is changed, the other G compressor 207 connected in parallel is gradually increased to increase the load; in dual stage operation, the principle of capacity of the elevator group is the same as in single stage.
In a word, the embodiment of the invention can respectively provide cold energy for the secondary refrigerant by using the cooling water, the single-stage compression refrigerating unit, the two-stage compression refrigerating unit, the overlapping unit and the overlapping unit combined with the two-stage compression in sequence.
The coolant cycle of embodiments of the present invention can also be used to separate the circulation of the externally circulating coolant between the end heat exchanger assemblies 309 and the coolant tank from the circulation of the internally circulating coolant between the bank heat exchangers and the coolant tank, and still be within the scope of the coolant cycle.
In the embodiment of the invention, the solution pumps 302 of each group of the cold carrying unit adopt a mode of respectively setting the liquid supply modes of the three high-temperature heat exchangers, the medium-temperature heat exchangers and the low-temperature heat exchangers in a one-to-one correspondence manner, and the pumps can be mutually standby in use. The actual process flow may be arranged in a one-to-one correspondence, or only a single set of pumps may be provided to feed three heat exchangers simultaneously, without departing from the basic spirit of the invention.
The invention only shows the necessary components and pipelines which form the embodiment of the invention, and neglects part of the components and pipelines, including the components which are usually needed to be added for facilitating the system maintenance and improving the reliability, such as a refrigeration pipeline related drying filter, an oil filter, a liquid viewing mirror, a stop valve, even a liquid spraying CIC component, a water path, a coolant pipeline commonly used maintenance valve, and for example, a low-temperature stage gas-liquid separator is not shown in the low-temperature stage unit 1 of the embodiment of the invention, generally, the gas separation can not be used in the screw machine gas return suction port, and the gas separation is used in the piston machine gas return suction port; the addition of components and piping to the actual system does not violate the basic spirit of the invention.
The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.
Claims (10)
1. The utility model provides a large-span cryogenic refrigeration system for proof box which characterized in that: the system comprises a cascade refrigeration high-temperature-level unit, a cascade refrigeration low-temperature-level unit, a cold-carrying unit and a cooling water circulation integration which are communicated with the cascade refrigeration high-temperature-level unit, the low-temperature-level unit and the cold-carrying unit; be provided with the condensation evaporimeter between high-temperature level unit and the low-temperature level unit, be provided with the medium temperature level evaporimeter between year cold machine group and the high-temperature level unit, be provided with the D evaporimeter between year cold machine group and the low-temperature level unit, the high-temperature level unit includes N parallelly connected G compressors, N the end of breathing in of G compressor all communicates in G collector of breathing in, and the exhaust end all communicates in G exhaust collector, N in the front N the collector that breathes in1Stage and back N2A G suction manifold and a G exhaust manifold between the G compressors are respectively provided with a through switch valve and a shunt three-way switch valve, wherein N is N1+N2And N is1≤N2And the angle valve side of the flow dividing three-way switch valve is communicated with the G suction manifold.
2. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 1, wherein: the G compressor is provided with a G oil return pipe and a G liquid spray pipe, the G oil return pipe is provided with an electromagnetic valve, each G oil return pipe is connected out of a G oil return collecting pipe and communicated to a G oil separator, the G oil separator is communicated with a G oil cooler, and an oil return pipeline connected with the G oil cooler is provided with an oil thermostatic valve; and the G liquid spraying pipes of the G compressor are all provided with liquid spraying pipeline electromagnetic valves, and each G liquid spraying pipe is connected with a liquid inlet pipe of a supercooling side pipeline of the G economizer.
3. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 2, wherein: the G air suction manifold is connected with the G gas-liquid separator; and an evaporation side gas return pipe of the G economizer is connected to a G gas suction header.
4. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 2, wherein: an outlet pipe of the G oil separator is connected to an inlet of a G condenser, an outlet of the G condenser is divided into two pipelines after passing through an electromagnetic valve and is respectively connected to pipe orifices on two sides of an evaporation side and a supercooling side of the G economizer, the electromagnetic valve and a temperature control type expansion valve are mounted on the pipeline on the evaporation side, and the outlet of the G economizer is connected to a G suction manifold; and the supercooling side inlet pipeline of the G economizer is respectively connected with three pipelines, and the three pipelines are respectively connected with G liquid spraying ports of the G compressors through G liquid spraying pipes where the liquid spraying pipe electromagnetic valves are located.
5. A long-span cryogenic refrigeration system for a test chamber as claimed in any one of claims 1 to 4, wherein: the number of the G compressors is 2 to 5.
6. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 1, wherein: the direct-connection switch valve and the shunt three-way switch valve are electric valves with associated electric actions, when the direct-connection switch valve is closed and the shunt three-way switch valve is simultaneously opened, a high-temperature stage unit formed by N parallel G compressors is switched into a two-stage compressor unit, wherein N is the high-temperature stage unit formed by N parallel G compressors2The platform parallel G compressors form a low-pressure stage unit of the two-stage unit, N1The parallel G compressors form a high-pressure stage unit of the double-stage unit.
7. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 1, wherein: the low-temperature-stage unit comprises M compressors and D compressors, exhaust ends of the M compressors and the D compressors are communicated with a D exhaust manifold, suction ends are communicated with a D suction manifold, an oil return end is communicated with a D oil return manifold after passing through an electromagnetic valve, the D oil return manifold is communicated with a D oil separator, the D oil separator is communicated with a D oil cooler, and an oil return pipeline connected with the D oil cooler is provided with an oil thermostatic valve; the D air suction manifold is connected with the D evaporator; and the D exhaust manifold is connected to the D oil separator through a D exhaust manifold.
8. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 7, wherein: the outlet pipe of the D oil separator is connected with the working medium side inlet of the D precooler, the working medium side outlet of the D precooler is connected with the working medium side inlet of the condensation evaporator, the working medium side outlet pipe of the condensation evaporator is divided into two pipelines after passing through the electromagnetic valve and is respectively connected with the pipe orifices on the two sides of the evaporation side and the supercooling side of the D economizer, the electromagnetic valve and the throttle valve are arranged on the pipeline on the evaporation side, and the outlet of the D economizer is connected with the economizer interface of the D compressor through the air return pipe of the D economizer and is controlled by the electromagnetic valve to be switched on and off.
9. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 7, wherein: the low-temperature-stage unit comprises a low-pressure expansion tank, and an expansion tank main pipe of the low-pressure expansion tank is connected with a D suction manifold; the D pressure relief pipe of the low-pressure expansion tank is connected with the D exhaust manifold; and an oil return pipe of the low-pressure expansion tank is connected with an oil return header D.
10. A large-span cryogenic refrigeration system for a test chamber as claimed in claim 1, wherein: the cold carrying unit comprises a cold carrying solution tank, a solution pump, a D evaporator, a medium-temperature evaporator, a high-temperature heat exchanger, a tail end heat exchanger assembly, a temperature adjusting control valve, an electric switch valve, an electromagnetic valve, a check valve and a check valve, wherein the solution pump is provided with L groups connected in parallel, the check valve is installed at the outlet of each solution pump, liquid is taken from the inlet of each solution pump to the cold carrying solution tank, the outlet of each solution pump is finally converged to a main pipe, the main pipe is connected with the D evaporator, the medium-temperature evaporator and the high-temperature heat exchanger respectively, each pipeline is controlled to be on-off through the electric switch valve, and liquid outlet pipelines of the D evaporator, the medium-temperature evaporator and the high-temperature heat exchanger are converged to a liquid supply main pipe through the check valve and are sent to the.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011395732.7A CN112484351A (en) | 2020-12-03 | 2020-12-03 | Large-span low-temperature refrigerating system for test box |
| PCT/CN2020/133803 WO2022116133A1 (en) | 2020-12-03 | 2020-12-04 | Wide-range low-temperature refrigeration system for test chamber |
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| CN202011395732.7A CN112484351A (en) | 2020-12-03 | 2020-12-03 | Large-span low-temperature refrigerating system for test box |
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| CN115751814A (en) * | 2022-11-11 | 2023-03-07 | 大连工业大学 | Calandria refrigeration house system and control method thereof |
| CN116358243B (en) * | 2023-05-25 | 2023-09-19 | 杭州杭氧低温容器有限公司 | Temperature control method for vertical and horizontal combined low-pressure container |
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| CN101576327B (en) * | 2009-05-27 | 2011-04-06 | 大连三洋压缩机有限公司 | Duel-temperature refrigeration cycle system |
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| WO2009062526A1 (en) * | 2007-11-13 | 2009-05-22 | Carrier Corporation | Refrigerating system and method for refrigerating |
| JP5819006B2 (en) * | 2012-10-22 | 2015-11-18 | 三菱電機株式会社 | Refrigeration equipment |
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