CN114963596A - Refrigerating system, damp-heat test chamber and control method of damp-heat test chamber - Google Patents
Refrigerating system, damp-heat test chamber and control method of damp-heat test chamber Download PDFInfo
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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
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
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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
- F25B41/00—Fluid-circulation arrangements
- F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
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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
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
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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
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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 provides a refrigeration system, a damp-heat test chamber and a control method of the damp-heat test chamber, which comprise the following steps: the cold-carrying circulation unit is a cold-carrying agent circulation loop and comprises a surface air cooler connected to the loop of the cold-carrying circulation unit, a first heat exchanger and a second heat exchanger which are connected in parallel in the cold-carrying agent circulation loop; the cooling unit is connected with the first heat exchanger, and a cooling water circulation loop is formed between the cooling unit and the first heat exchanger; the refrigerating unit is connected with the second heat exchanger, and a refrigerant circulating loop is formed between the refrigerating unit and the second heat exchanger; the temperature sensor is arranged on the cold-carrying circulating unit and used for detecting the temperature of the cold-carrying agent flowing into the surface cooler; and the control unit is used for controlling the proportion of the secondary refrigerant which exchanges heat with the cooling unit and the refrigerating unit in the secondary cooling circulation unit so as to accurately control the temperature of the secondary refrigerant flowing into the surface cooler.
Description
Technical Field
The invention relates to the technical field of refrigeration, in particular to a refrigeration system, a damp-heat test box and a control method of the damp-heat test box.
Background
The damp-heat test box is necessary test equipment in the fields of aviation, automobiles, household appliances, scientific research and the like, and is used for testing and determining parameters and performances of electricians, electronics and other products and materials after temperature environment changes of high temperature, low temperature, damp-heat degree or constant tests. With the continuous development of environmental test technology, the national standards committee is also continuously adjusting the standards of environmental simulation tests, and at present, the requirements on the harsh grade of a damp-heat test are higher and higher aiming at some special industries, so that the comprehensive performance of environmental simulation experimental equipment with the damp-heat function is also higher, for example: humidity control precision under the damp and hot mode, stability of long-term operation, surface cooler frost prevention performance under a low-temperature and low-humidity state, equipment energy consumption performance and the like.
The existing refrigeration system of the damp-heat test box is usually provided with a surface air cooler in the damp-heat test box, and the refrigeration system expands in the surface air cooler to absorb heat through a direct expansion mode of a refrigerant to generate the refrigeration effect. Because the expansion speed of the refrigerant can not be controlled, the temperature of the surface air cooler can not be changed drastically, and therefore the temperature of the surface air cooler can not be controlled accurately, the difference between the evaporation temperature of the refrigerant inside the surface air cooler and the dew point temperature of the space environment in the damp-heat operation process of the equipment is huge, when the temperature of an evaporator in the surface air cooler is lower than 0 ℃ (the temperature of an external fin of the surface air cooler approaches to O ℃), the dew point of the ambient air is higher because the equipment is in a damp-heat operation state, the frosting condition is easy to occur on the surface of the surface air cooler, the heat exchange efficiency of the surface air cooler is influenced, and the surface air cooler can not work normally. And the adverse phenomena of poor humidity control stability, temperature and humidity drift and the like occur in the damp and hot operation process of the equipment.
Disclosure of Invention
The invention aims to provide a refrigeration system, a damp-heat test chamber and a control method of the damp-heat test chamber, so as to solve the technical problems in the prior art.
The invention provides a refrigeration system, comprising:
the cold-carrying circulation unit is a cold-carrying agent circulation loop and comprises a surface air cooler connected to the loop of the cold-carrying circulation unit, a first heat exchanger and a second heat exchanger which are connected in parallel in the cold-carrying agent circulation loop;
the cooling unit is connected with the first heat exchanger, and a cooling water circulation loop is formed between the cooling unit and the first heat exchanger;
the refrigeration unit is connected with the second heat exchanger, and a refrigerant circulation loop is formed between the refrigeration unit and the second heat exchanger;
a temperature sensor disposed on the cold-carrying cycle unit to detect a temperature of the coolant flowing into the surface cooler;
and the control unit is used for controlling the proportion of the secondary refrigerant which exchanges heat with the cooling unit and the refrigerating unit in the secondary cooling circulation unit according to the comparison between the current temperature of the secondary refrigerant detected by the temperature sensor and the actually required target temperature of the secondary refrigerant so as to accurately control the temperature of the secondary refrigerant flowing into the surface air cooler.
According to the refrigeration system provided by the embodiment of the invention, the cold carrying circulation unit further comprises:
the buffering branch and the surface cooler are connected in parallel in a secondary refrigerant circulation loop;
the control unit comprises a first control valve and a first calculating unit, the first control valve is connected in the secondary refrigerant circulation loop and used for controlling the proportion of secondary refrigerant entering the surface cooler and the buffering branch, and the first calculating unit is used for calculating the required flow of the secondary refrigerant of the surface cooler according to the current required refrigerating capacity of the surface cooler to control the opening degree of the first control valve.
According to the refrigeration system provided by the embodiment of the invention, the first control valve comprises a three-way proportional regulating valve.
According to the refrigeration system provided by the embodiment of the invention, the control unit comprises:
and the second control valve is connected in the secondary refrigerant circulating loop and used for controlling the proportion of secondary refrigerant entering the first heat exchanger and the second heat exchanger.
According to the refrigeration system provided by the embodiment of the invention, the second control valve comprises a three-way proportional regulating valve.
According to the refrigeration system provided by the embodiment of the invention, the target temperature is a dew point temperature of a simulated environment, the refrigeration system further comprises an atmospheric environment temperature detector and an atmospheric environment humidity detector, and the control unit further comprises a second calculating unit, wherein the second calculating unit is used for calculating the dew point temperature of the atmospheric environment according to a temperature value detected by the atmospheric environment temperature detector and a humidity value detected by the atmospheric environment humidity detector.
According to the refrigeration system provided by the embodiment of the invention, the cold carrying circulation unit comprises:
and the buffer water tank is connected in the secondary refrigerant circulation loop, an inlet of the buffer water tank is communicated with secondary refrigerant outlets of the first heat exchanger and the second heat exchanger, and an outlet of the buffer water tank is communicated with the control unit.
According to an embodiment of the present invention, there is provided a refrigeration system including: a compressor, a condenser, an electromagnetic valve and an expansion valve which are connected into the refrigerant circulation loop;
and a cooling water inlet of the condenser is communicated with a water outlet pipeline of the cooling unit through a first pipeline, and a cooling water outlet of the condenser is communicated with a water return pipeline of the cooling unit through a second pipeline.
According to the refrigeration system provided by the embodiment of the invention, the cooling unit comprises: the cooling tower comprises a cooling tower and a cooling water circulating pump, wherein a water outlet of the cooling tower is communicated with a cooling water inlet of the first heat exchanger through the water outlet pipeline, a water inlet of the cooling tower is communicated with a cooling water outlet of the first heat exchanger through the water return pipeline, and the cooling water circulating pump is arranged on the water outlet pipeline or the water return pipeline.
The embodiment also provides a damp heat test box, including:
a box body; the refrigeration system as described in the previous embodiment; wherein the surface cooler is arranged in the box body.
The embodiment further provides a control method of the damp-heat test chamber, which is applied to the damp-heat test chamber in the above embodiment, and the control method includes:
judging the dew point temperature of the current simulation environment of the damp and hot test box and the dew point temperature of the atmospheric environment; and if the dew point temperature of the atmospheric environment is higher than that of the simulated environment, controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigerating unit according to the dew point temperature of the simulated environment and the temperature of the secondary refrigerant flowing into the surface cooler.
According to the control method provided by the embodiment of the invention, the control method further comprises the following steps: controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigerating unit to maintain a predetermined relationship between the temperature of the secondary refrigerant flowing into the surface air cooler and the dew point temperature of the simulated environment, wherein the predetermined relationship is as follows: the temperature of the coolant flowing into the surface air cooler is equal to the dew point temperature of the simulated environment minus a predetermined temperature difference.
According to the control method provided by the embodiment of the invention, the preset temperature difference is 5-8 ℃.
According to the control method provided by the embodiment of the invention, the step of controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigeration unit comprises the following steps:
when the damp-heat test box is started, controlling the proportion of the secondary refrigerant flowing into the surface cooler according to a first preset proportion, wherein in the first preset proportion, the proportion of the secondary refrigerant flowing into the surface cooler is smaller than the proportion of the secondary refrigerant flowing into a buffering branch circuit connected with the surface cooler in parallel;
and after the first preset time is maintained, controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigerating unit according to the dew point temperature of the simulated environment and the temperature of the secondary refrigerant flowing into the surface cooler.
According to the control method provided by the embodiment of the invention, the first preset proportion is that the proportion of the secondary refrigerant flowing into the surface cooler is 75% -95% of the secondary refrigerant flow of the secondary cooling cycle unit;
and/or
The first predetermined time is 1 minute or more.
According to the control method provided by the embodiment of the invention, the control method further comprises the following steps:
if the dew point temperature of the atmospheric environment is lower than the dew point temperature of the simulated environment, whether the temperature of the current atmospheric environment is higher than a preset temperature value of the temperature of the initial atmospheric environment is further judged, and if the temperature of the current atmospheric environment is higher than the preset temperature value, the cold carrying circulation unit is controlled to carry out heat exchange with the cooling unit, and the heat exchange with the cooling unit is stopped.
According to the control method provided by the embodiment of the invention, the preset temperature value is 5 ℃.
According to the control method provided by the embodiment of the invention, the control method further comprises the following steps:
when the damp-heat test box is started, controlling the proportion of the secondary refrigerant flowing into the surface cooler according to a second preset proportion, wherein in the second preset proportion, the proportion of the secondary refrigerant flowing into the surface cooler is greater than the proportion of the secondary refrigerant flowing into a buffering branch circuit connected with the surface cooler in parallel;
and after the second preset time is maintained, controlling the proportion of the secondary refrigerant flowing into the surface air cooler according to the temperature change of the simulated environment and the temperature of the secondary refrigerant flowing into the surface air cooler.
According to the control method provided by the embodiment of the invention, the second preset proportion is that the proportion of the secondary refrigerant flowing into the surface cooler is 67% -79% of the secondary refrigerant flow of the secondary cooling cycle unit;
and/or
The second predetermined time is 1 minute or more.
The basis of traditional dry bulb temperature and the like for system temperature control is an ideal state, the deviation from the actual state is large, the temperature control fluctuation is large, and accurate temperature control cannot be realized, because the atmospheric environment dew point temperature can change along with different seasons (winter, summer), weather (cloudy days, rainy days, fine days) and the like, therefore, after the target of the simulated environment temperature and humidity is determined, the accuracy of system temperature control can be improved by considering the difference of the atmospheric environment dew point temperature under the condition that the simulated environment dew point temperature obtained by calculation is determined. The refrigerating system provided by the invention controls the temperature of the secondary refrigerant in the secondary cooling circulation unit by respectively carrying out heat exchange with the cooling unit and the refrigerating unit through the first heat exchanger and the second heat exchanger arranged in the secondary cooling circulation unit, and controls the proportion of the secondary refrigerant which carries out heat exchange with the cooling unit and the refrigerating unit in the secondary cooling circulation unit through the control unit to accurately control the temperature of the secondary refrigerant flowing into the surface air cooler. Furthermore, the invention obtains the simulated dew point temperature through calculation as the basis for realizing the accurate control of the surface air cooler by the switching system, realizes the system switching and the system cold quantity control through the comparison of the simulated dew point temperature and the atmospheric environment dew point temperature, can realize the accurate control, avoids the problems of the surface air cooler such as frosting and the like, and further improves the temperature control accuracy through the fixed valve control and the regulation of a PID controller.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic structural diagram of a refrigeration system provided by an embodiment of the present invention;
FIG. 2 is a diagram of an operating state when the dew point temperature of the atmospheric environment is higher than that of the simulated environment in the embodiment of the control method of the damp-heat test chamber provided by the invention;
fig. 3 is a working state diagram when the dew point temperature of the atmospheric environment is lower than the dew point temperature of the simulation environment in the embodiment of the control method of the damp-heat test chamber provided by the invention.
Description of the main element symbols: 100-cold carrying circulation unit; 10-surface cooler; 20-a first heat exchanger; 30-a second heat exchanger; 200-a cooling unit; 300-a refrigeration unit; 50-a temperature sensor; 11-a buffer water tank; 111-an input port; 112-an output port; 101-a working branch; 1012-low temperature interface; 1011-high temperature interface; 103-cooling branch; 102-a refrigeration branch; 104-buffer branch; 1041-a first buffer interface; 1042 — a second buffer interface; 41-a first control valve; 42-a second control valve; 21-a cooling tower; 22-a cooling circuit; 31-a refrigeration device; 32-refrigeration circuit.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.
As shown in fig. 1, an embodiment of the present invention provides a refrigeration system including:
the cold-carrying circulating unit 100 is a cold-carrying agent circulating loop and comprises a surface air cooler 10 connected to the loop of the cold-carrying circulating unit 100, a first heat exchanger 20 and a second heat exchanger 30 which are connected in parallel in the cold-carrying agent circulating loop;
a cooling unit 200 connected to the first heat exchanger 20 and forming a cooling water circulation loop with the first heat exchanger 20;
a refrigeration unit 300 connected to the second heat exchanger 30 and forming a refrigerant circulation circuit with the second heat exchanger 30;
a temperature sensor 50 provided at the cold-carrying cycle unit 100 to detect a temperature of the coolant flowing into the surface cooler 10;
and a control unit for controlling the proportion of the coolant in the cooling cycle unit 100 that exchanges heat with the cooling unit 200 and the refrigeration unit 300 according to a comparison between the current temperature of the coolant detected by the temperature sensor 50 and an actually required target temperature of the coolant, so as to accurately control the temperature of the coolant flowing into the surface cooler 10.
The target temperature is the dew point temperature of the simulated environment, the refrigeration system further comprises an atmospheric environment temperature detector and an atmospheric environment humidity detector, the control unit further comprises a calculation unit, and the calculation unit is used for calculating the dew point of the atmospheric environment according to the temperature value detected by the atmospheric environment temperature detector and the humidity value detected by the atmospheric environment humidity detector. Then, the opening degree of the second control valve 42 is calculated and controlled by calculating the dew point temperature of the simulated environment according to the target temperature and the target humidity of the simulated environment to be simulated and the actual humidity of the current environment.
Wherein, the dew point temperature calculation formula is as follows:
t: temperature of dry bulb
t 1: dew point temperature
C: humidity
C＝[B-(t-t1)*0.0699]/A*100
In the refrigeration system, in the cold-carrying circulation unit 100, the secondary refrigerant flows into the surface cooler 10 and then undergoes heat exchange in the surface cooler 10, so that the temperature of the secondary refrigerant flowing out of the surface cooler 10 is increased, and the secondary refrigerant may undergo heat exchange with the cooling unit 200, or with the refrigeration unit 300, or may undergo heat exchange with the cooling unit 200 and the refrigeration unit 300 simultaneously in proportion under the control of the control unit, so as to achieve the purpose of reducing the temperature. In the present embodiment, the cooling unit 200 mainly functions to cool the coolant in the circulation circuit to a preset temperature, such as an ambient temperature, or a temperature of a specific environment (i.e., a temperature in the cooling unit 200), by heat exchange. On this basis, the refrigeration unit 300 may continue to lower the temperature of the coolant to a lower temperature through heat exchange, wherein the lower temperature is lower than the preset temperature that the cooling unit 200 may provide. Therefore, when the coolant exchanges heat with the cooling unit 200 or the refrigeration unit 300, different temperatures can be obtained, so that when the coolant exchanges heat with the cooling unit 200 or the refrigeration unit 300 in proportion, the coolant can obtain various temperatures by adjusting the proportion of the coolant entering the cooling unit 200 or the refrigeration unit 300.
On this basis, the control unit may control the ratio of the coolant in the coolant circulation unit 100 to the coolant that exchanges heat with the cooling unit 200 and the refrigeration unit 300, so as to precisely control the temperature of the coolant flowing into the surface cooler 10, and thus precisely control the temperature of the surface cooler 10. In a preferred embodiment, the control unit may control the ratio of the coolant to be heat-exchanged with the cooling unit 200 and the refrigerating unit 300 according to a preset target temperature to be reached by the surface cooler 10. In one embodiment, for example, when the cooling system is applied to the thermal-humidity test chamber, and the temperature to be reached by the thermal-humidity test chamber is set by the user, the control unit can obtain the temperature to be reached by the thermal-humidity test chamber set by the user from the operation interface of the thermal-humidity test chamber, and control the ratio of the coolant in the cold-carrying circulation unit 100 to the coolant for exchanging heat with the cooling unit 200 and the cooling unit 300 according to the temperature, so as to achieve the purpose of accurately controlling the temperature of the thermal-humidity test chamber.
Specifically, based on the above embodiments, the types of the coolant can be selected according to the minimum temperature condition to be achieved by the surface air cooler 10, and the common coolant can be divided into: water, ethylene glycol aqueous solution, inorganic salt aqueous solution, silicone oil, and the like.
Specifically, in an alternative embodiment, the cooling cycle unit 100 may include:
a buffer tank 11, said buffer tank 11 comprising an input port 111 and an output port 112;
the working branch 101 is connected with the surface cooler 10, the working branch 101 comprises a low-temperature interface 1012 and a high-temperature interface 1011, the low-temperature interface 1012 is connected with the output port 112, and coolant enters the surface cooler 10 through the low-temperature interface 1012;
a cooling branch 103 for exchanging heat with the cooling unit 200, wherein one end of the cooling branch 103 is connected to the high temperature interface 1011 through the control unit, and the other end is connected to the input port 111;
a refrigeration branch 102 for exchanging heat with the refrigeration unit 300, wherein one end of the refrigeration branch 102 is connected to the high temperature interface 1011 through the control unit, and the other end is connected to the input port 111;
the buffering branch 104 is connected in parallel with the surface cooler 10 in the coolant circulation loop, and the buffering branch 104 includes a first buffering interface 1041 and a second buffering interface 1042; the first buffer interface 1041 is connected to the working branch 101 between the surface cooler 10 and the high temperature interface 1011, and the second buffer interface 1042 is connected to the output port 112 and the low temperature interface 1012 through the control unit.
The control unit includes a first control valve 41, and the first control valve 41 is connected in the coolant circulation circuit and is used for controlling the ratio of the coolant entering the surface cooler 10 and the buffer branch 104.
The control unit controls the proportion of the secondary refrigerant in the secondary cooling circulation unit 100 to the secondary refrigerant subjected to heat exchange with the cooling unit 200 and the refrigeration unit 300, so that the secondary refrigerant is subjected to heat exchange with the cooling unit 200 and the refrigeration unit 300 at the same time in proportion, and if the secondary refrigerants in the cooling branch 103 and the refrigeration branch 102 subjected to heat exchange with the cooling unit 200 and the refrigeration unit 300 at the same time are directly converged into the working branch 101, the secondary refrigerants subjected to heat exchange with different temperatures cannot be sufficiently mixed, so that the temperature of the secondary refrigerant in the working branch 101 is possibly uneven due to the fact that the secondary refrigerants with different temperatures cannot be sufficiently mixed, and the temperature of the surface cooler 10 is further influenced. In this embodiment, a buffer water tank 11 is provided, such that the cooling branch 103 and the refrigeration branch 102 are connected to the input port 111 of the buffer water tank 11, and the coolant in the cooling branch 103 and the refrigeration branch 102 is subjected to sufficient heat exchange in the buffer water tank 11, so as to make the temperature of the coolant flowing out of the buffer water tank 11 uniform.
In this embodiment, the control unit can control the ratio of the coolant flowing out of the outlet 112 into the surface cooler 10, so that the coolant flows into the surface cooler 10 and the buffer branch 104 according to the ratio set by the control unit, and when the external environment of the surface cooler 10 changes, the surface cooler 10 maintains the temperature in a space at a certain value if necessary, and the temperature in the space changes due to the change of the heat radiation amount of other heat sources, the temperature of the surface cooler 10 can be controlled to adapt to the change by adjusting the ratio of the coolant flowing into the surface cooler 10. Further, when the refrigeration system is started, the temperature change speed of the surface cooler 10 can be controlled by controlling the proportion of the secondary refrigerant entering the surface cooler 10, so that inaccurate temperature control caused by severe temperature change is prevented, and especially in some occasions needing low temperature generation, the temperature change speed of the surface cooler 10 is controlled, so that the frosting phenomenon of the surface cooler 10 can be prevented.
Specifically, the first control valve 41 is respectively connected to the output port 112, the low temperature interface 1012, and the second buffer interface 1042, and is used for controlling a ratio of coolant flowing from the output port 112 to the low temperature interface 1012 and the second buffer interface 1042. Preferably, the first control valve 41 may be a three-way proportional control valve.
On this basis, the control unit comprises: a second control valve 42 is connected in the coolant circulation circuit for controlling the ratio of coolant entering the first and second heat exchangers 20, 30. The second control valve 42 is connected to the high temperature interface 1011, the cooling branch 103 and the refrigeration branch 102, respectively, and is configured to control a ratio of coolant flowing from the high temperature interface 1011 to the cooling branch 103 and the refrigeration branch 102. Preferably, the second control valve 42 may be a three-way proportional control valve.
Specifically, in the present embodiment, the cooling unit 200 includes: cooling tower 21, cooling water circulating pump and cooling circuit 22, cooling circuit 22 includes outlet pipe way and return water pipeline, the delivery port of cooling tower 21 passes through outlet pipe way with the cooling water entry intercommunication of first heat exchanger 20, the water inlet of cooling tower 21 passes through return water pipeline with the cooling water export intercommunication of first heat exchanger 20, the cooling water circulating pump sets up outlet pipe way or return water is on the road. The cooling tower 21 is provided with cooling liquid. Alternatively, water may be used as the cooling liquid. The cooling system using the cooling tower 21 is well known in the art and therefore will not be described in detail.
Specifically, the first heat exchanger may be connected to the cooling circuit 22 and the cooling cycle unit 100, respectively. Heat exchange between the cold-carrying cycle unit 100 and the cooling circuit 22 may be achieved by the first heat exchanger 20.
Since the coolant in the cold-carrying cycle unit 100 and the coolant in the cooling circuit 22 can be different materials, the first heat exchanger can be a plate heat exchanger or other available heat exchangers, and is not limited in particular.
Specifically, in the present embodiment, the refrigeration unit 300 includes: a refrigeration device 31 and a refrigeration circuit 32 connected to the refrigerant circulation circuit, the refrigeration device 31 including a compressor, a condenser, a solenoid valve, and an expansion valve; the refrigeration circuit 32 is configured to circulate a refrigerant and controllably form heat exchange with the refrigeration cycle unit 100, and the compressor, the condenser, the solenoid valve, and the expansion valve are all connected to the refrigeration circuit 32. The cooling water import of condenser through first pipeline with cooling unit 200's outlet pipe way intercommunication, the cooling water export of condenser through the second pipeline with cooling unit 200's return water pipeline intercommunication, cooling unit 200 can take away the heat with the condensation heat that produces on the condenser of refrigerating unit 300 through the cooling water and arrange to outdoor from cooling tower 21 to guarantee refrigerating unit 300's normal use like this. A phase change refrigerant refrigeration system using a compressor and a condenser is well known in the art, and therefore, the details thereof are not described.
On this basis, the second heat exchanger is connected to the refrigeration circuit 32 and the cooling cycle unit 100, respectively. Heat exchange between the cooling cycle unit 100 and the refrigeration circuit 32 may be achieved by the second heat exchanger 30. Since the coolant in the cold-carrying cycle unit 100 and the coolant in the refrigeration circuit 32 may be different materials, the second heat exchanger may be a plate heat exchanger or other available heat exchangers, and is not limited in particular.
It should be noted that the above examples are only used to illustrate the feasibility of the embodiments of the present invention, and it should be understood that the scope of the present invention is not limited by the contents of the above examples.
In the present invention, there is also provided an embodiment of the damp heat test chamber, which includes: the box body further comprises a refrigerating system provided by the embodiment; and the surface cooler 10 is disposed in the case to control the temperature in the case.
In the embodiment of the damp-heat test box, the refrigeration system can be used as a refrigeration module of the damp-heat test box, when the damp-heat test box needs to simulate a temperature higher than the environment, the interior of the box is usually heated by the heating module, if a thermal load exists in the box and continuously radiates heat into the box in the scene, the temperature in the box may gradually rise and be separated from control, at this time, the temperature in the box needs to be balanced by refrigerating the box by the refrigeration module to realize accurate control of the temperature in the box, in the prior art, the refrigeration module of the damp-heat test box directly adopts a phase-change material to enter the surface air cooler 10 for phase-change expansion, which easily causes the temperature of the surface air cooler 10 to be violently reduced, so that the temperature in the box cannot be accurately balanced, whereas in the embodiment described above, the temperature of the surface air cooler 10 can be accurately controlled by a coolant with accurately controlled cooling and refrigeration ratios in the scene, thereby realizing accurate balance of the temperature in the box body. When the damp-heat test box needs to simulate the temperature lower than the environment, the box body can be usually refrigerated through the refrigeration module, and in the prior art, the refrigeration module of the damp-heat test box directly adopts the phase-change material to enter the surface air cooler 10 for phase change expansion, so that the temperature of the surface air cooler 10 is easily reduced violently, if the temperature needing to be simulated is low, if the temperature is close to the freezing point, the temperature of the surface air cooler 10 can be rapidly reduced to be below the freezing point, in addition, the humidity environment simulated in the damp-heat test box easily causes the surface of the surface air cooler 10 to frost, and the surface air cooler 10 can not work normally. In the above-described embodiment of the present application, the temperature of the secondary refrigerant entering the surface air cooler 10 can be accurately controlled by accurately controlling the cooling-refrigerating ratio of the secondary refrigerant, and the ratio of the secondary refrigerant entering the surface air cooler 10 can be accurately controlled, so that the temperature of the secondary refrigerant entering the surface air cooler 10 can be accurately controlled, and the heat exchange speed between the surface air cooler 10 and the inside of the box body can be accurately controlled, thereby accurately controlling the temperature inside the box body, and overcoming the defect that the surface air cooler 10 frosts in the prior art.
In the present invention, there is also provided an embodiment of a control method for a damp-heat test chamber, which is applicable to the above-described embodiment of the damp-heat test chamber, and may further include:
judging the dew point temperature of the current simulation environment of the damp and hot test box and the dew point temperature of the atmospheric environment; if the dew point temperature of the atmospheric environment is higher than the dew point temperature of the simulated environment, the ratio of the coolant exchanging heat with the cooling unit 200 and the refrigeration unit 300 is controlled according to the dew point temperature of the simulated environment and the temperature of the coolant flowing into the surface air cooler 10.
The working state of this embodiment is shown in fig. 2, and it can be seen from fig. 2 that the coolant in the cold-carrying circulation unit 100 proportionally flows into the cooling branch 103 and the cooling branch 102 under the control of the second control valve 42, enters the first heat exchanger 20 to exchange heat with the cooling unit 200, and enters the second heat exchanger 30 to exchange heat with the cooling unit 300, and then the coolant enters the buffer tank 11 along the cooling branch 103 and the cooling branch 102, and enters the surface cooler 10 through the working branch 101, and the redundant coolant is branched to the buffer branch 104 through the second buffer interface 1042 of the first control valve 41 to realize the flow regulation in the surface cooler 10. The temperature sensor 50 detects the temperature of the coolant entering the surface cooler 10, and the second control valve 42 obtains the temperature of the coolant entering the surface cooler 10 according to the detection of the temperature sensor 50, and accurately controls the proportion of the coolant flowing into the cooling branch 103 and the cooling branch 102 according to the dew point temperature of the simulated environment set by a user, so as to accurately control the temperature of the coolant entering the surface cooler 10. Alternatively, the second control valve 42 may be controlled by a PID (proportional-integral-derivative) controller.
The software control system is provided with two independent sets of PIDs, wherein PID 1 is used for controlling the temperature of the refrigerating medium, PID 2 is used for controlling the flow of the refrigerating medium entering the surface cooler 10 (which can be understood as the refrigerating capacity of the surface cooler 10), for example: when the dew point temperature in the environment simulation space is required to be-3 ℃, the target temperature (-3 ℃) of the secondary refrigerant is calculated through No. 1 PID, then the analog quantity signal is output and acts on the second control valve 42, the flow of the secondary refrigerant entering the first heat exchanger 20 (higher temperature) and the second heat exchanger 30 (lower temperature) is accurately controlled through the opening degree of the valve, and after heat exchange in the heat exchangers, the cold-hot secondary refrigerant is uniformly mixed in the buffer water tank 11, so that the aim of accurately controlling the temperature is fulfilled. Similarly, the PID No. 2 is used to control the opening degree of the first control valve 41, so as to control the flow rate of the coolant entering the surface cooler 10, thereby realizing flexible control of the cooling capacity of the surface cooler 10.
On the basis of the above embodiment, optionally, the embodiment may further include:
the ratio of the coolant heat-exchanged with the cooling unit 200 and the refrigerating unit 300 is controlled such that the temperature of the coolant flowing into the surface air cooler 10 maintains a predetermined relationship with the dew point temperature of the simulated environment. On this basis, the predetermined relationship may include: the coolant flowing into the surface cooler 10 has a temperature equal to the simulated ambient dew point temperature minus a predetermined temperature differential. In this embodiment, the temperature of the coolant flowing into the surface cooler 10 is lower than the dew point of the simulated environment by a predetermined temperature difference, so that the surface cooler 10 and the simulated environment of the thermal-humidity test chamber form a heat exchange temperature difference, and the simulated environment of the surface cooler 10 and the thermal-humidity test chamber can exchange heat. Meanwhile, when the temperature of the surface cooler 10 is lower than the dew point temperature of the simulated environment, the surface cooler 10 can work under a wet working condition, and the heat exchange capacity of the surface cooler 10 can be improved. Alternatively, the predetermined temperature difference may be 5-8 degrees Celsius. When the equipment is in operation, for example, a damp-heat test of 20 ℃ (dry-bulb temperature) 95% (humidity) is carried out, and the dew point temperature of the humidity point is calculated as follows: 19.17 ℃, then we need to control the temperature of the chilled water (coolant) at this point: 19.17-8 ℃ is about 11.17 ℃, namely the temperature of the frozen water is controlled as follows: the set dew point temperature is about-8 ℃, so as to ensure the heat exchange temperature difference.
On the basis of the above embodiment, optionally, the embodiment may further include:
the controlling of the ratio of the refrigerants that heat-exchange with the cooling unit 200 and the refrigerating unit 300 may further include:
when the damp-heat test box is started, controlling the proportion of the secondary refrigerant flowing into the surface cooler 10 according to a first preset proportion, wherein in the first preset proportion, the proportion of the secondary refrigerant flowing into the surface cooler 10 is smaller than the proportion of the secondary refrigerant flowing into the buffering branch 104 connected with the surface cooler 10 in parallel;
after the first predetermined time is maintained, the ratio of the coolant exchanging heat with the cooling unit 200 and the refrigeration unit 300 is controlled according to the dew point temperature of the simulated environment and the temperature of the coolant flowing into the surface cooler 10.
Preferably, the first predetermined ratio is 75% to 95% of the coolant flow of the cold cycle unit 100 to flow into the surface cooler 10.
Preferably, the first predetermined time is 1 minute or more; until the temperature in the coolant circulation circuit of the cold-carrying circulation unit 100 reaches the heat exchange working temperature. In this embodiment, in order to cool the simulated environment in a scenario where the dew point temperature of the atmospheric environment is higher than the dew point temperature of the simulated environment, the ratio of the coolant exchanging heat with the cooling unit 300 may be increased, and the ratio of the coolant exchanging heat with the cooling unit 200 may be decreased, so that the temperature of the simulated environment may be rapidly decreased.
The control unit distributes the flow of the coolant flowing into the first heat exchanger 20 and the second heat exchanger 30 by automatically calculating a desired target temperature in a simulated environment and turning on the refrigeration unit 300 with the second control valve 42 as an actuator of the control unit. The heat exchange media of the first heat exchanger 20 are as follows: the temperature of the cooling water is influenced by the ambient temperature, so that the temperature of the secondary refrigerant can be controlled to be about the external ambient temperature after the heat exchange of the secondary refrigerant is carried out by the first heat exchanger 20. The heat exchange medium of the second heat exchanger 30 is: the coolant-coolant has a low evaporation temperature, so that the coolant can be cooled to a relatively low temperature after exchanging heat with the coolant in the second heat exchanger 30. The higher-temperature secondary refrigerant cooled by the first heat exchanger 20 and the lower-temperature secondary refrigerant cooled by the second heat exchanger 30 simultaneously flow into the buffer water tank 11 to be fully fused, and then are sent into the surface air cooler 10 by a secondary refrigerant circulating pump (located on an outlet water path of the buffer water tank 11) to control the ambient humidity. In this operating scenario, the degree of opening of the second control valve 42 (i.e., controlling the flow of coolant distributed to the first heat exchanger 20 and the second heat exchanger 30) is based on the target temperature of the coolant to be controlled, which is detected by the temperature sensor 50. In addition, in the working scenario, the flow rate of the coolant entering the surface cooler 10 can be precisely controlled by the first control valve 41: that is, under the condition that the temperature of the secondary refrigerant is constant, the flow rate of the secondary refrigerant entering the surface cooler 10 is adjusted through the first control valve 41 to adjust the heat exchange amount of the surface cooler 10 in due time to adapt to or match the uncontrollable heat load change of the space environment, so as to ensure the reliable and stable operation of the equipment in the damp and hot state.
Specifically, in a scenario where the dew point temperature of the atmospheric environment is higher than the dew point temperature of the simulated environment, that is, when the refrigeration system operates under a low dew point condition, the opening degree of the low temperature interface 1012 is controlled to be 5% to 25%, the opening degree of the second buffer interface 1042 is controlled to be 75% to 95%, the opening degree of the low temperature interface 1012 is smaller than the opening degree of the second buffer interface 1042, the opening degree is maintained for more than one minute, and the opening degree is converted into a PID controller No. 2 for control. The low temperature interface 1012 controls the flow rate of the coolant flowing through the surface air cooler 10 at the non-target operating temperature in the initial stage, i.e., uses a small flow rate, to reduce the supply of cooling capacity of the surface air cooler 10 in the initial stage and reduce the amount of condensation in this stage. The coolant flow through the first heat exchanger 20 is increased to allow the coolant flow of the refrigeration system to reach the temperature required for the operation of the surface air cooler 10 as quickly as possible. And through the refrigeration unit 300 additionally arranged, the problem that the condensation amount is large due to the fact that the surface air cooler 10 is cooled excessively and quickly when the cold amount is provided excessively at the initial stage when the PID controller is adjusted is solved.
Therefore, by the control method provided by the embodiment, under the condition that the multi-factor temperature fluctuation of the environmental temperature, the temperature of the surface air cooler 10, the cooling water temperature and the like is large in the initial stage, the PID controller in the refrigeration system controls excessive adjustment of the valve, the surface air cooler 10 in the initial stage provides excessive cooling capacity, the quantity of heat taken away is excessive, the cooling rate of the surface air cooler is too high, the condensation quantity on the surface air cooler is large, the possibility of frost formation is higher when the temperature is low, namely the dehumidification quantity is large, and in order to maintain the humidity in the test box, the humidifier in the test box increases the humidification quantity, even the quantity of heat taken away by the surface air cooler is excessive, and heating and temperature compensation are possibly needed, so that the temperature is increased when the PID controller controls excessive adjustment of the valve, and the problems of condensation and frost formation of the surface air cooler 10 (when the PID controller adjusts, the temperature of the refrigeration system is too low for heat exchange, and the temperature of the coolant is too low) are avoided. And the heat exchange of the secondary refrigerant in the first heat exchanger 20 is improved through the large flow of the second control valve 42, so that the secondary refrigerant can more efficiently and more quickly reach the water temperature of the cooling water unit, namely the normal temperature. And to provide more flow to exchange heat with the refrigeration unit 300. In the initial stage, the first control valve 41 is controlled to fix the proportional opening of the valve, and after the opening of the valve is controlled to be maintained for a period of time, the opening of the first control valve 41 is accurately controlled after being calculated by the control unit through the number 2 PID controller, so that accurate temperature adjustment can be realized. From this, adopt first control valve 41 fixed valve proportion aperture and No. 2 PID controller become the dual regulation mode of the degree of opening of first control valve 41 reduces surface cooler 10 dewfall and dewfall volume, heat consumption, humidification volume can avoid surface cooler 10 dewfall volume big, heat consumption promotion, and the big scheduling problem of humidification volume realizes that the temperature is quick, accurate adjustment. The problems of frosting of the surface air cooler 10 and the like can be avoided, and the temperature can be adjusted quickly and accurately.
In an optional embodiment, further comprising:
if the dew point temperature of the atmospheric environment is lower than the dew point temperature of the simulated environment, further determining whether the current temperature of the atmospheric environment is higher than a preset temperature value of the initial temperature of the atmospheric environment (i.e., determining whether a heat source exists in the simulated environment), and if the current temperature of the atmospheric environment is higher than the preset temperature value, controlling the cooling circuit to perform heat exchange with the cooling unit 200 and stopping performing heat exchange with the cooling unit 300.
The working state of this embodiment is as shown in fig. 3, since the dew point temperature of the atmospheric environment is lower than the dew point temperature of the simulation environment, the simulation environment of the damp-heat test chamber does not need to be cooled, but due to the heat source existing in the simulation environment, the temperature in the simulation environment is continuously increased due to the continuous radiation of the heat source, and if the heat value of the heat source is large, the temperature in the simulation environment may be out of control. At this time, the cold-carrying agent can only exchange heat with the cooling unit 200, so that the cooled cold-carrying agent enters the surface air cooler 10, and the surface air cooler 10 cools the simulated environment to balance the heat emitted by the heat source in the simulated environment, thereby achieving the purpose of accurately controlling the temperature of the damp-heat test chamber.
The dew point temperature of the simulated environment is obtained through calculation and is used as the basis for realizing the accurate control of the surface air cooler by the switching system, the system switching and the system cooling capacity control are realized by calculating the comparison between the dew point temperature of the simulated environment and the dew point temperature of the environment, the environment dew point temperature is close to the temperature of water in a cooling tower and a pipeline thereof in the cooling water system, and under the condition that the simulated environment dew point temperature (namely the calculated dew point temperature in a test box) is higher than the dew point temperature of the atmospheric environment, the cooling requirement can be realized only by using the cold quantity in the cooling water system, because a refrigerating system is not required to be added, the cooling is realized by using the cooling water system only, the energy is saved, and the temperature fluctuation is smaller.
Preferably, the preset temperature value is 5 ℃.
On the basis of the above embodiments of the control method for the damp-heat test chamber, further, an optional embodiment is further provided, where the method further includes:
when the damp-heat test box is started, controlling the proportion of the secondary refrigerant flowing into the surface air cooler 10 according to a second preset proportion, wherein the proportion of the secondary refrigerant flowing into the surface air cooler 10 is greater than the proportion of the secondary refrigerant flowing into a buffering branch 104 connected with the surface air cooler 10 in parallel;
and after the second preset time, controlling the proportion of the secondary refrigerant flowing into the surface air cooler 10 according to the temperature change of the simulated environment and the temperature of the secondary refrigerant flowing into the surface air cooler 10.
In this embodiment, the coolant in the cold-cycle unit 100 flows proportionally into the surface cooler 10 and the buffer branch 104 under the control of the first control valve 41, and the first control valve 41 can control the proportion of the coolant flowing into the cooling branch 103 and the cooling branch 102 according to a second predetermined proportion, so as to achieve the purpose of accurately controlling the temperature of the coolant entering the surface cooler 10, prevent the temperature of the surface cooler 10 from being changed drastically, and overcome the defect that frosting may be caused when a low temperature is simulated. Alternatively, the first control valve 41 may be controlled by a PID controller.
Preferably, the second predetermined ratio is 67% -79% of the coolant flow of the cold-carrier cycle unit to the surface cooler 10.
Preferably, the second predetermined time is 1 minute or more; until the temperature in the coolant circulation loop of the cold-carrying circulation unit 100 reaches the heat exchange working temperature.
Specifically, when the dew point temperature of the atmospheric environment is lower than the dew point temperature of the simulated environment, that is, when the refrigeration system operates under a high dew point condition. The cooling water circulation pump is first started, cooling water circulates first, so that the temperature of water in the pipeline reaches the heat exchange working temperature, the valve opening degree of the second control valve 42 is controlled to close the valve flowing into the refrigeration branch 102, the valve opening degree of the first control valve 41 is controlled to be 21-33% of the outlet opening degree of the second buffer connector 1042, the outlet opening degree of the low-temperature connector 1012 is 67-79%, and the opening degree is kept for more than one minute. The opening degree of the first control valve 41 is accurately controlled after being calculated by a control unit through a number 2 PID controller, and then the outlet opening degree of the second buffer interface 1042 and the outlet opening degree of the low-temperature interface 1012 are adjusted to realize temperature adjustment in the working scene.
Specifically, under this working scenario, the cooling water circulating pump is first turned on, and the cooling water circulates first, so that the water temperature in the pipeline reaches the heat exchange working temperature, and this refrigeration system is subsequently operated, because the cooling water temperature in the pipeline connected to the cooling tower 21 is not the actual water temperature of the cooling tower 21, the direct operation of heat exchange makes the temperature after heat exchange deviate, which causes the deviation between the temperature of the surface air cooler 10 and the expected temperature. And the cooling water circulating pump is started first to reduce the temperature deviation. In the initial stage, the proportional valve opening of the first control valve 41 is fixed, and the PID controller is controlled by the control unit to regulate the proportional valve opening after a certain period of time. And the outlet aperture of the low temperature interface 1012 is larger and fixed in the initial stage, so that the surface cooler 10 can be adjusted in temperature at a fixed cooling rate while the surface cooler 10 is cooled, and the problems that the surface cooler 10 is excessively adjusted to increase the temperature and excessive dewing occurs to the surface cooler 10 under the condition of large fluctuation of multi-factor temperatures such as the environment temperature, the surface cooler 10 temperature, the cooling water temperature and the like in the initial stage (such as excessive secondary refrigerant flow in the initial stage, excessive heat brought away, too fast cooling rate of the surface cooler, large dewing amount on the surface cooler, namely large dehumidifying amount, increased humidifying amount of a humidifier in the test box in order to maintain the humidity in the test box, even excessive heat brought away by the surface cooler, and possibly heating and temperature compensation are needed, therefore, the secondary refrigerant temperature is controlled inaccurately, which causes the problems of dewing amount, heat consumption increase, large amount and the like) and the like are avoided, after fixed valve proportion aperture, the control of constant temperature variable speed kept a period of time, the degree of opening of first control valve 41 is calculated by the control unit through No. 2 PID controllers and is carried out accurate control after, can realize the accurate temperature adjustment of secondary refrigerant, and then accurate control the cold volume that secondary refrigerant provided in the surface cooler 10, from this, adopt first control valve 41 fixed valve proportion aperture and No. 2 PID controllers become the dual regulation mode of the degree of opening of first control valve 41 reduces surface cooler 10 dewfall volume, heat consumption, humidification volume can be avoided surface cooler 10 dewfall volume is big, heat consumption promotes, and the big scheduling problem of humidification volume realizes that the temperature is quick, accurate adjustment.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (19)
1. A refrigeration system, comprising:
the cold-carrying circulation unit is a cold-carrying agent circulation loop and comprises a surface air cooler connected to the loop of the cold-carrying circulation unit, a first heat exchanger and a second heat exchanger which are connected in parallel in the cold-carrying agent circulation loop;
the cooling unit is connected with the first heat exchanger, and a cooling water circulation loop is formed between the cooling unit and the first heat exchanger;
the refrigeration unit is connected with the second heat exchanger, and a refrigerant circulation loop is formed between the refrigeration unit and the second heat exchanger;
a temperature sensor disposed on the cold-carrying cycle unit to detect a temperature of the coolant flowing into the surface cooler;
and the control unit is used for controlling the proportion of the secondary refrigerant which exchanges heat with the cooling unit and the refrigerating unit in the secondary cooling circulation unit according to the comparison between the current temperature of the secondary refrigerant detected by the temperature sensor and the actually required target temperature of the secondary refrigerant, so as to accurately control the temperature of the secondary refrigerant flowing into the surface air cooler.
2. The refrigeration system of claim 1, wherein the cold carrier cycle unit further comprises a buffer branch connected in parallel with the surface cooler in a coolant circulation loop;
the control unit comprises a first control valve and a first calculating unit, the first control valve is connected in the secondary refrigerant circulation loop and used for controlling the proportion of secondary refrigerant entering the surface cooler and the buffering branch, and the first calculating unit is used for calculating the required flow of the secondary refrigerant of the surface cooler according to the current required refrigerating capacity of the surface cooler so as to control the opening degree of the first control valve.
3. The refrigerant system as set forth in claim 2, wherein said first control valve includes a three-way proportional regulating valve.
4. The refrigerant system as set forth in claim 1, wherein said control unit includes:
and the second control valve is connected in the secondary refrigerant circulating loop and used for controlling the proportion of secondary refrigerant entering the first heat exchanger and the second heat exchanger.
5. The refrigerant system as set forth in claim 4, wherein said second control valve includes a three-way proportional regulating valve.
6. The refrigeration system according to claim 4, wherein the target temperature is a dew point temperature of a simulated environment, the refrigeration system further comprises an atmospheric environment temperature detector and an atmospheric environment humidity detector, and the control unit further comprises a second calculation unit for calculating the dew point temperature of the atmospheric environment according to a temperature value detected by the atmospheric environment temperature detector and a humidity value detected by the atmospheric environment humidity detector.
7. The refrigeration system as recited in any one of claims 1 to 6, wherein the cold-carrying cycle unit comprises:
and the buffer water tank is connected in the secondary refrigerant circulation loop, an inlet of the buffer water tank is communicated with secondary refrigerant outlets of the first heat exchanger and the second heat exchanger, and an outlet of the buffer water tank is communicated with the control unit.
8. A refrigeration system as set forth in any of claims 1-6 and including: a compressor, a condenser, a solenoid valve, and an expansion valve connected to the refrigerant circulation circuit;
and a cooling water inlet of the condenser is communicated with a water outlet pipeline of the cooling unit through a first pipeline, and a cooling water outlet of the condenser is communicated with a water return pipeline of the cooling unit through a second pipeline.
9. The refrigeration system of claim 8, wherein the cooling unit comprises: the cooling tower comprises a cooling tower and a cooling water circulating pump, wherein a water outlet of the cooling tower is communicated with a cooling water inlet of the first heat exchanger through the water outlet pipeline, a water inlet of the cooling tower is communicated with a cooling water outlet of the first heat exchanger through the water return pipeline, and the cooling water circulating pump is arranged on the water outlet pipeline or the water return pipeline.
10. A damp heat test chamber, comprising:
a box body; a refrigeration system according to any one of claims 1 to 9; wherein the surface cooler is arranged in the box body.
11. A control method of a damp-heat test chamber, applied to the damp-heat test chamber according to claim 10, comprising:
judging the dew point temperature of the current simulation environment of the damp and hot test box and the dew point temperature of the atmospheric environment; and if the dew point temperature of the atmospheric environment is higher than that of the simulated environment, controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigerating unit according to the dew point temperature of the simulated environment and the temperature of the secondary refrigerant flowing into the surface cooler.
12. The control method according to claim 11, characterized by further comprising: controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigerating unit to maintain a predetermined relationship between the temperature of the secondary refrigerant flowing into the surface air cooler and the dew point temperature of the simulated environment, wherein the predetermined relationship is as follows: the temperature of the coolant flowing into the surface air cooler is equal to the dew point temperature of the simulated environment minus a predetermined temperature difference.
13. The control method according to claim 12, characterized in that the predetermined temperature difference is 5-8 degrees celsius.
14. The method of claim 12, wherein the step of controlling the proportion of the coolant that exchanges heat with the cooling unit and the refrigeration unit comprises:
when the damp-heat test box is started, controlling the proportion of the secondary refrigerant flowing into the surface cooler according to a first preset proportion, wherein in the first preset proportion, the proportion of the secondary refrigerant flowing into the surface cooler is smaller than the proportion of the secondary refrigerant flowing into a buffering branch circuit connected with the surface cooler in parallel;
and after the first preset time is maintained, controlling the proportion of the secondary refrigerant exchanging heat with the cooling unit and the refrigerating unit according to the dew point temperature of the simulated environment and the temperature of the secondary refrigerant flowing into the surface cooler.
15. The control method according to claim 14, wherein the first predetermined proportion is 75% to 95% of the coolant flow of the cold-cycle unit flowing into the surface cooler;
and/or
The first preset time is more than or equal to 1 minute until the temperature in the secondary refrigerant circulation loop in the secondary cooling circulation unit reaches the heat exchange working temperature.
16. The control method according to claim 11, characterized by further comprising:
if the dew point temperature of the atmospheric environment is lower than the dew point temperature of the simulated environment, whether the temperature of the current atmospheric environment is higher than a preset temperature value of the temperature of the initial atmospheric environment is further judged, and if the temperature of the current atmospheric environment is higher than the preset temperature value, the cold carrying circulation unit is controlled to carry out heat exchange with the cooling unit, and the heat exchange with the cooling unit is stopped.
17. The control method according to claim 16, wherein the preset temperature value is 5 degrees celsius.
18. The control method according to claim 11 or 16, characterized by further comprising:
when the damp-heat test box is started, controlling the proportion of the secondary refrigerant flowing into the surface cooler according to a second preset proportion, wherein in the second preset proportion, the proportion of the secondary refrigerant flowing into the surface cooler is greater than the proportion of the secondary refrigerant flowing into a buffering branch circuit connected with the surface cooler in parallel;
and after the second preset time is maintained, controlling the proportion of the secondary refrigerant flowing into the surface air cooler according to the temperature change of the simulated environment and the temperature of the secondary refrigerant flowing into the surface air cooler.
19. The control method as recited in claim 18 wherein the second predetermined proportion is 67% -79% of the coolant flow to the surface cooler;
and/or
And the second preset time is more than or equal to 1 minute until the temperature in the secondary refrigerant circulating loop in the secondary cooling circulating unit reaches the heat exchange working temperature.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010003347A1 (en) * | 1999-12-08 | 2001-06-14 | Kazuyoshi Shimoda | Temperature control device for thermal medium Fluid |
| CN1975287A (en) * | 2006-12-07 | 2007-06-06 | 苏州昆拓冷机有限公司 | Energy-saving refrigerator set |
| CN102999070A (en) * | 2012-10-10 | 2013-03-27 | 合肥天鹅制冷科技有限公司 | Device capable of accurately controlling temperature and humidity |
| CN203364526U (en) * | 2013-05-20 | 2013-12-25 | 青岛中和实验室技术装备有限公司 | Dew-point control system suitable for environmental testing |
| CN212253245U (en) * | 2020-06-05 | 2020-12-29 | 东莞信易电热机械有限公司 | Water cooling machine with multiple water outlet temperature regulation and control functions |
| CN113457752A (en) * | 2021-08-04 | 2021-10-01 | 江苏拓米洛环境试验设备有限公司 | Control method of alternating damp-heat test chamber and alternating damp-heat test chamber |
-
2021
- 2021-12-30 CN CN202111680961.8A patent/CN114963596B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010003347A1 (en) * | 1999-12-08 | 2001-06-14 | Kazuyoshi Shimoda | Temperature control device for thermal medium Fluid |
| CN1975287A (en) * | 2006-12-07 | 2007-06-06 | 苏州昆拓冷机有限公司 | Energy-saving refrigerator set |
| CN102999070A (en) * | 2012-10-10 | 2013-03-27 | 合肥天鹅制冷科技有限公司 | Device capable of accurately controlling temperature and humidity |
| CN203364526U (en) * | 2013-05-20 | 2013-12-25 | 青岛中和实验室技术装备有限公司 | Dew-point control system suitable for environmental testing |
| CN212253245U (en) * | 2020-06-05 | 2020-12-29 | 东莞信易电热机械有限公司 | Water cooling machine with multiple water outlet temperature regulation and control functions |
| CN113457752A (en) * | 2021-08-04 | 2021-10-01 | 江苏拓米洛环境试验设备有限公司 | Control method of alternating damp-heat test chamber and alternating damp-heat test chamber |
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| CN114963596B (en) | 2023-09-26 |
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Denomination of invention: Control methods for refrigeration systems, humidity and heat test chambers, and humidity and heat test chambers Granted publication date: 20230926 Pledgee: China Minsheng Banking Corp Chongqing branch Pledgor: CHONGQING ARTEST CAN SCIENCE AND TECHNOLOGY Co.,Ltd. Registration number: Y2024980019419 |