CN109341121B - Refrigeration system and control method - Google Patents
Refrigeration system and control method Download PDFInfo
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- CN109341121B CN109341121B CN201811366700.7A CN201811366700A CN109341121B CN 109341121 B CN109341121 B CN 109341121B CN 201811366700 A CN201811366700 A CN 201811366700A CN 109341121 B CN109341121 B CN 109341121B
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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
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/31—Expansion 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
- 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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- 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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- 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
- F25B49/027—Condenser control arrangements
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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
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/01—Heaters
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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
- F25B2600/00—Control issues
- F25B2600/11—Fan speed control
- F25B2600/111—Fan speed control of condenser fans
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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
- F25B2600/00—Control issues
- F25B2600/25—Control of 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2513—Expansion 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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
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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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2117—Temperatures of an evaporator
- F25B2700/21171—Temperatures of an evaporator of the fluid cooled by the evaporator
- F25B2700/21173—Temperatures of an evaporator of the fluid cooled by the evaporator at the outlet
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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
Abstract
The invention provides a refrigeration system and a control method, wherein the refrigeration system comprises: a compressor, a condenser, an electronic expansion valve and an evaporator; the cooling medium pipeline is communicated with a cooled medium and communicated with the evaporator, so that the refrigerant and the cooled medium exchange heat in the evaporator; and the temperature controller is arranged on the cooling medium pipeline and is arranged on the air outlet side of the condensation fan so as to exchange heat between the hot air blown out by the condensation fan and the cooled medium passing through the cooling medium pipeline in the temperature controller. According to the invention, the cooled medium in the cooling medium pipeline can be heated and heated in the temperature controller through the hot air blown out by the condensing fan, the condensing waste heat is fully utilized for heating the cooling medium to a target temperature range, the stability of the refrigerating system is improved, the electric heating with poor safety is not needed, the design difficulty is reduced, and the performance, reliability and safety of the system are improved.
Description
Technical Field
The invention belongs to the technical field of air conditioners, and particularly relates to a refrigeration system and a control method.
Background
In the refrigeration air-conditioning industry, hot gas bypass technology is often used for defrosting or adjusting the evaporation temperature; on digital scroll compressors, the hot gas bypass primarily serves a load shedding role to reduce capacity output. Most of vapor compression type heat pump/refrigeration units do not need to specially carry out high-low pressure balance treatment when the unit is stopped, the unit can be placed through stopping for a period of time to achieve high-low pressure balance, the high-low pressure balance state can be achieved within minutes usually, and the compressor can not be started under pressure when being restarted.
In some cold water units or oil cooling units with precisely controlled required temperature, hot gas bypass directly leads part of high-temperature and high-pressure refrigerant into the inlet end of the evaporator after throttling, and the refrigerant is mixed with the original throttled low-temperature and low-pressure refrigerant liquid, so that the pressure and the temperature of the inlet of the evaporator are improved, and the outlet temperature of the cooled liquid is further influenced. This practice often results in fluctuations in the refrigerant system, too long a settling time, and correspondingly the outlet temperature of the cooled liquid (i.e., the control target) also fluctuates, sometimes not as stable as the original control.
In order to solve the fluctuation of the mutual influence, some precise units adopt an auxiliary electric heating technology to increase the temperature of the cooled liquid to a target temperature range, and precise heating capacity output is implemented on auxiliary electric heating through silicon controlled rectifier and other designs. But the disadvantages are that extra electric energy is consumed, the safety of electric heating is poor, and the hardware design and software control of the controller are complicated by the thyristor. Obviously, the problems of stability of control and safety and reliability of electric heating of the refrigeration system are solved, and the problems are key problems of the precise refrigeration unit.
Because the refrigeration system in the prior art has the technical problems that the temperature adjustment of a cooled medium fluctuates and is unstable, even the fluctuation of the refrigeration system is caused, the stabilization time is too long, correspondingly, the outlet temperature (namely, a control target) of the cooled liquid also fluctuates, the cooled medium can not reach the target temperature quickly, the stability of the refrigeration system can not be influenced, extra electric energy needs to be consumed, the safety ratio of electric heating is poor, the hardware design and software control of a controller by silicon control are complex, and the like, the refrigeration system and the control method are researched and designed.
Disclosure of Invention
Therefore, the technical problem to be solved by the present invention is to overcome the defects that the refrigeration system in the prior art cannot simultaneously achieve the purpose that the cooled medium rapidly and stably reaches the target temperature, the stability of the refrigeration system is not affected, and additional electric energy does not need to be consumed, so as to provide a refrigeration system and a control method.
The present invention provides a refrigeration system comprising:
the system comprises a compressor, a condenser, a condensing fan, an electronic expansion valve and an evaporator;
the cooling medium pipeline is communicated with a cooled medium and communicated with the evaporator, so that the refrigerant and the cooled medium exchange heat in the evaporator;
and the temperature controller is arranged on the cooling medium pipeline and is arranged on the air outlet side of the condensation fan, so that heat exchange is carried out between hot air blown out by the condensation fan and a cooled medium passing through the cooling medium pipeline in the temperature controller.
Preferably, the first and second electrodes are formed of a metal,
the temperature controller is arranged on the cooling medium pipeline and is positioned at the downstream section of the evaporator along the flow direction of the cooled medium.
Preferably, the first and second electrodes are formed of a metal,
the thermostat includes the wind channel and sets up the blast gate of wind channel entrance, the blast gate can be controlled the wind channel is opened and is closed and adjust the aperture size.
Preferably, the first and second electrodes are formed of a metal,
and a first temperature sensor is arranged on the cooling medium pipeline at the inlet end of the temperature controller.
Preferably, the first and second electrodes are formed of a metal,
and a second temperature sensor is arranged on the cooling medium pipeline and positioned at the outlet end of the temperature controller.
Preferably, the first and second electrodes are formed of a metal,
when the first temperature sensor is included, the first temperature sensor is a temperature sensing bulb; when a second temperature sensor is included, the second temperature sensor is a bulb.
Preferably, the first and second electrodes are formed of a metal,
the thermostat is finned heat exchanger, just finned heat exchanger includes the cooling tube of outer wall area annular fin or the cooling tube of outer wall area longitudinal fin, just the cooling tube of outer wall area annular fin arrange into the tube axis direction with the air-out direction of condensation fan is mutually perpendicular, the cooling tube of outer wall area longitudinal fin arrange into the tube axis direction with the air-out direction of condensation fan parallels.
Preferably, the first and second electrodes are formed of a metal,
the cooled medium is water, and the water is introduced into the cooling medium pipeline, passes through the evaporator to be cooled, and then passes through the temperature controller to be heated.
The invention also provides a control method of the refrigerating system, which uses the refrigerating system to realize accurate control on the temperature of the cooled medium.
Preferably, the first and second electrodes are formed of a metal,
when the temperature controller comprises a first temperature sensor and a second temperature sensor, the temperature of a cooling medium inlet of the temperature controller detected by the first temperature sensor is Tb, and the temperature of the cooling medium outlet of the temperature controller detected by the second temperature sensor is Ta; setting the target temperature of the cooled medium to Ts;
when the refrigeration system is started, the frequency of the compressor and/or the opening of the electronic expansion valve and/or the rotating speed of the condensing fan are/is adjusted, so that the temperature Tb reaches Ts + △ t, and the accuracy △ t is a first accuracy error.
Preferably, the first and second electrodes are formed of a metal,
and when Ts- △ t- △ t1 is not less than Tb and not more than Ts + △ t, maintaining the current operation states of the compressor, the electronic expansion valve and the condensing fan, wherein △ t1 is a second precision error.
Preferably, the first and second electrodes are formed of a metal,
when Tb is less than Ts- △ t- △ t1 and an air valve is included, the air valve is opened to heat the cooled medium through the temperature controller until Ts- △ t- △ t1 is less than or equal to Tb and less than or equal to Ts + △ t.
Preferably, the first and second electrodes are formed of a metal,
judging whether the outlet temperature Ta of the cooling medium meets Ts- △ t and does not exceed △ t, and if so, maintaining the opening of the existing air valve;
when Ts-Ta is larger than △ t, the opening degree of the air valve is increased, the larger the difference between Ts-Ta is, until Ta reaches- △ t which is not less than Ts-Ta which is not less than △ t, and at the moment, the opening degree of the air valve is maintained;
when Ts-Ta < - △ t, the air valve is closed, and at least one of the frequency increase of the compressor, the opening degree increase of the electronic expansion valve and the rotation speed increase of the condensation fan is adjusted to increase the refrigerating capacity.
The refrigeration system and the control method provided by the invention have the following beneficial effects:
1. the invention arranges the temperature controller on the cooling medium pipeline; the temperature controller is arranged on the air outlet side of the condensing fan so as to exchange heat between hot air blown out by the condensing fan and a cooled medium in a cooling medium pipeline in the temperature controller; can heat the intensification by coolant in the coolant pipeline through the hot-blast quilt that the condensation fan blew off in the thermostat, make full use of condensation used heat is used for heating coolant to the target temperature scope, need not to carry out more accurate adjustment to refrigerating system's load, make the fluctuation range of the freezing medium temperature of evaporimeter export can suitably be enlargied, can not cause the obvious fluctuation of refrigerant state in the evaporimeter, thereby refrigerating system's stability has been improved, need not the poor electric heating of security, system performance and reliability have been promoted when reducing the design degree of difficulty, the security.
2. According to the invention, through the arrangement of the first temperature sensor, the second temperature sensor and the air valve, the opening degree of the air valve can be adjusted according to the deviation value of the outlet temperature of the freezing medium in the evaporator and the target temperature, so that the hot air blown out from the air-cooled finned tube condenser passes through the temperature controller and the radiating tube to heat the low-temperature chilled water until the outlet water temperature reaches the control target.
Drawings
Fig. 1 is a schematic configuration diagram of embodiment 1 of the refrigeration system of the present invention;
fig. 2 is a schematic configuration diagram of embodiment 2 of the refrigeration system of the present invention.
The reference numbers in the figures denote:
1. a compressor; 2. a condenser; 21. a condensing fan; 3. an electronic expansion valve; 4. an evaporator; 5. a cooling medium line; 6. a temperature controller; 61. an air duct; 62. a radiating pipe; 8. an air valve; 91. a first temperature sensor; 92. a second temperature sensor.
Detailed Description
As shown in fig. 1-2, the present invention provides a refrigeration system comprising:
the system comprises a compressor 1, a condenser 2, a condensing fan 21, an electronic expansion valve 3 and an evaporator 4;
a cooling medium pipeline 5, wherein a cooled medium is introduced into the cooling medium pipeline 5, and the cooling medium pipeline 5 is introduced into the evaporator 4, so that the refrigerant and the cooled medium exchange heat in the evaporator 4;
the temperature controller 6 is arranged on the cooling medium pipeline 5, and the temperature controller 6 is arranged on the air outlet side of the condensation fan 21, so that the hot air blown out by the condensation fan 21 exchanges heat with the cooled medium passing through the cooling medium pipeline 5 in the temperature controller 6 (heats the cooled medium). (the thermostat of the present invention essentially functions as a heat exchanger so that the refrigerant and the medium to be cooled exchange heat therebetween, and the thermostat is not limited to a specific structure, i.e., the sections that exchange heat between the refrigerant bypass branch and the cooling medium pipe can be referred to as thermostats).
The invention arranges the temperature controller on the cooling medium pipeline; the temperature controller is arranged on the air outlet side of the condensing fan so as to exchange heat between hot air blown out by the condensing fan and a cooled medium in a cooling medium pipeline in the temperature controller; can heat the intensification by coolant in the coolant pipeline through the hot-blast quilt that the condensation fan blew off in the thermostat, make full use of condensation used heat is used for heating coolant to the target temperature scope, need not to carry out more accurate adjustment to refrigerating system's load, make the fluctuation range of the freezing medium (by coolant promptly) temperature of evaporimeter export can suitably be enlargied, can not cause the obvious fluctuation of refrigerant state in the evaporimeter, thereby refrigerating system's stability has been improved, need not the poor electric heating of security, the system performance and reliability have been promoted when reducing the design degree of difficulty, safety.
Preferably, the first and second electrodes are formed of a metal,
the temperature controller 6 is arranged on the cooling medium pipeline 5 and is positioned at the downstream section of the evaporator 4 along the flow direction of the cooled medium. The temperature controller is preferably arranged at the downstream section of the evaporator, so that the cooled medium enters the evaporator to be cooled and then is heated and heated by the temperature controller, and the temperature of the cooled medium is accurately controlled or finely adjusted, thereby realizing accurate and stable control of the temperature of the cooled medium. The former is subjected to a large-scale temperature reduction treatment, and the latter is subjected to a slight temperature rise adjustment treatment to a target temperature.
In the conventional cooling treatment method, the amount of refrigerant entering the evaporator is adjusted by directly adjusting the electronic expansion valve, and the stabilization speed of the system is very slow when the temperature reaches a target temperature range. On the basis, the target temperature can be quickly reached, but the temperature rise processing speed of the supercooled chilled water is higher, the quick and stable control can be realized, the energy-saving performance of the temperature rise processing of electric heating can be replaced, the influence on a machine tool caused by the over-low temperature of the chilled water is avoided, a long time is needed for the new stabilization process to be reached after the new stabilization process is controlled by various fluctuations of a refrigerating unit in the conventional method, and the long-time stabilization control process is required for the new stabilization control to be reached when the temperature of the chilled water is too high, which is a defect of the conventional temperature control technology.
Preferably, the first and second electrodes are formed of a metal,
Preferably, the first and second electrodes are formed of a metal,
a first temperature sensor 91 is arranged on the cooling medium pipeline 5 at the inlet end of the temperature controller 6; a second temperature sensor 92 is arranged on the cooling medium line 5 at the outlet end of the temperature controller 6. The temperature sensor is arranged at the inlet end of the temperature controller, so that the temperature of the cooled medium before entering the temperature controller can be detected, and the second temperature sensor is arranged at the outlet end of the temperature controller, so that the temperature of the cooled medium after entering the temperature controller can be detected; the temperature of the freezing medium (low-temperature freezing water) at the outlet of the evaporator is compared with a temperature control target, the required heating amount is calculated according to the deviation amount, and then the air valve is accurately controlled, so that the freezing medium in the temperature controller is accurately heated to the target temperature, and the rapid and stable temperature control target is realized; sensible heat exchange and graded temperature control are adopted in the temperature controller, so that the stability of the system is facilitated.
According to the invention, through the arrangement of the first temperature sensor, the second temperature sensor and the air valve, the required hot gas bypass refrigerant amount can be estimated according to the deviation amount of the outlet temperature of the freezing medium in the evaporator and the target temperature, so that the bypass refrigerant hot gas is accurately controlled, and the accurate, rapid and stable refrigeration system is realized; according to the difference between the temperature sensing bulb A (outlet temperature) and the set temperature, the opening degree of the air valve is determined to adjust and control the heat exchange in the temperature controller, so that the low-temperature chilled water can be accurately heated and adjusted.
Preferably, the first and second electrodes are formed of a metal,
when the first temperature sensor 91 is included, the first temperature sensor 91 is a bulb; when a second temperature sensor 92 is included, the second temperature sensor 92 is a bulb. This is a preferred form of construction for the first and second temperature sensors of the invention.
Preferably, the first and second electrodes are formed of a metal,
the thermostat 6 is a finned heat exchanger, and the finned heat exchanger includes a heat dissipation tube 62 (embodiment 1, as shown in fig. 1) having an annular fin on an outer wall thereof or a heat dissipation tube 62 (embodiment 2, as shown in fig. 2) having a longitudinal fin on an outer wall thereof, and the heat dissipation tube 62 having an annular fin on an outer wall thereof is arranged such that a tube axis direction is perpendicular to an air outlet direction of the condensation fan, and the heat dissipation tube 62 having a longitudinal fin on an outer wall thereof is arranged such that a tube axis direction is parallel to the air outlet direction of the condensation fan. The two different optimal structural forms of the temperature controller are that the radiating pipe with the annular fins on the outer wall is arranged, the axis of the radiating pipe is perpendicular to the air outlet direction, so that heat exchange can be carried out between hot air and the fins with the maximum efficiency, the heat exchange efficiency is improved, and the radiating pipe with the longitudinal fins on the outer wall is arranged in parallel to the air outlet direction, so that heat exchange can be carried out between the hot air and the fins with the maximum efficiency, and the heat exchange efficiency is improved.
The invention comprises the following steps: 1. the low-temperature chilled water enters a radiating pipe of the temperature controller, and the low-temperature chilled water is heated by hot air flowing through the outside of the radiating pipe and with controlled air volume; the hot air quantity is adjusted by the opening degree of a controllable air valve, and the opening degree of the air valve is adjusted and controlled according to the relation between the low-temperature chilled water and the target temperature; the temperature controller can be internally provided with hot air transverse sweeping annular finned radiating tubes (namely the axes of the hot tubes are vertical to the air outlet direction), or hot air longitudinal sweeping longitudinal finned radiating tubes (namely the axes of the hot tubes are parallel to the air outlet direction), so that the hot air emitted by the finned tube condenser is fully utilized.
2. The temperature of the freezing medium (low-temperature frozen water) at the outlet of the evaporator is compared with a temperature control target, the required heating amount is calculated according to the deviation amount, and then the opening degree of an air valve is accurately controlled to adjust the air quantity of hot air passing through the temperature controller, so that the freezing medium in the temperature controller is accurately heated to the target temperature, and the rapid and stable temperature control target is realized; sensible heat exchange and graded temperature control are carried out in the temperature controller, the regulation of a refrigeration system is not involved, and the stability of the temperature control of the system is improved.
Preferably, the first and second electrodes are formed of a metal,
the cooled medium is water, and the water is introduced into the cooling medium pipeline 5, passes through the evaporator 4 to be cooled, and then passes through the temperature controller 6 to be heated. The cooling medium is the preferable type of the cooled medium, and can be controlled by water to reach the accurate temperature and then cool the precise part, so that the cooling effect is improved.
As shown in fig. 1 and 2, the compressor, the condenser (in this embodiment, an air-cooled finned tube condenser is shown), the throttle element (in this embodiment, an electronic expansion valve is shown as an example), and the evaporator are connected in this order, and the refrigerant flows in the same direction as this order, thereby forming a basic refrigeration cycle.
The air outlet direction of the finned tube condenser is provided with a temperature controller, the air inlet of the temperature controller is controlled by an air valve, partial hot air is blown into the temperature controller by utilizing the residual pressure of a condensing fan, and the flow of the hot air passing through the temperature controller is controlled by utilizing the opening degree of the air valve, so that the sensible heat exchange capacity in the temperature controller is controlled.
The thermostat includes an air duct (i.e., air duct 61), a controllable air valve at the inlet of the air duct, and a heat dissipation pipe. The radiating pipe can be provided with annular fins on the outer wall or longitudinal fins on the outer wall, and a finned tube heat exchanger or a micro-channel heat exchanger can be adopted to replace the two radiating pipes. Preferably, the hot air transverse-sweeping annular ribbed radiator (as shown in fig. 1) and the hot air longitudinal-sweeping longitudinal ribbed radiator (as shown in fig. 2).
The method comprises the following steps that water entering a water system firstly passes through an evaporator, is cooled to be low-temperature water, then flows out of the evaporator and enters a temperature controller, and a temperature sensing bulb B (namely a first temperature sensor 91) is arranged on a water pipe, connected with the temperature controller, of the evaporator and used for detecting the temperature of the low-temperature water (low-temperature chilled water); the low-temperature chilled water flows out of the temperature controller after being accurately heated to a controlled target temperature by external hot air after entering the temperature controller, and a temperature sensing bulb A (namely a second temperature sensor 92) is arranged on the outlet water pipe and used for detecting the temperature of the water.
The arrangement positions of the thermal bulb A and the thermal bulb B are not affected by hot air blowing, and inaccurate detection is avoided.
Preferably, the high temperature water inlet pipe is provided with a thermal bulb C for detecting the temperature of the high temperature water inlet (not shown in the figure).
The invention also provides a control method of the refrigeration system, which uses the refrigeration system in any one of the above items to realize accurate control on the temperature of the cooled medium. The temperature controller is arranged on the cooling medium pipeline; the temperature controller is arranged on the air outlet side of the condensing fan so as to exchange heat between hot air blown out by the condensing fan and a cooled medium in a cooling medium pipeline in the temperature controller; can heat the intensification by coolant in the coolant pipeline through the hot-blast quilt that the condensation fan blew off in the thermostat, make full use of condensation used heat is used for heating coolant to the target temperature scope, need not to carry out more accurate adjustment to refrigerating system's load, make the fluctuation range of the freezing medium temperature of evaporimeter export can suitably be enlargied, can not cause the obvious fluctuation of refrigerant state in the evaporimeter, thereby refrigerating system's stability has been improved, need not the poor electric heating of security, system performance and reliability have been promoted when reducing the design degree of difficulty, the security.
Preferably, the first and second electrodes are formed of a metal,
when the first temperature sensor 91 and the second temperature sensor 92 are included, the first temperature sensor 91 detects that the cooling medium inlet temperature of the thermostat 6 is Tb, and the second temperature sensor 92 detects that the cooling medium outlet temperature of the thermostat 6 is Ta; setting the target temperature of the cooled medium to Ts;
when the refrigeration system is started, the frequency of the compressor and/or the opening degree of the electronic expansion valve and/or the rotating speed of the condensing fan are/is adjusted, so that the temperature of Tb is less than or equal to Tb and less than or equal to Ts + △ t, wherein △ t is a first precision error, and the fastest speed (generally, the operation parameters in a memory state are adopted for starting and running, and the optimal operation combination parameters of the organic unit in the memory state are adopted for starting and running).
This is the preferred control method of the present invention for starting the refrigeration system according to the inlet temperature of the cooling medium, which can make the cooled medium cooled down to below the error range of the target temperature Ts by the evaporator, and thus can make the temperature of the cooled medium fall below the error range of the target temperature range, so as to further raise the temperature to make the water temperature reach within the error range of the target temperature.
Preferably, the first and second electrodes are formed of a metal,
when Ts- △ t- △ t1 is not less than Tb not less than Ts + △ t, the current operation state of the compressor, the electronic expansion valve and the condensing fan is maintained, wherein △ t1 is a second precision error, which is a specific control mode of the invention according to the condition that the inlet temperature of the cooled medium is within the error range of the target temperature, Ts- △ t- △ t1 not less than Tb not less than Ts + △ t shows that the inlet temperature of the cooled medium is within the error range of the target set temperature, and at the moment, the temperature of the cooled medium can be maintained within the target temperature range only by maintaining the current states of the compressor, the electronic expansion valve and the condensing fan, and the required requirements are met, preferably △ t-0.5 ℃ and △ t 1-0.5 ℃.
Preferably, the first and second electrodes are formed of a metal,
when Tb is less than Ts- △ t- △ t1 and an air valve is included, the air valve 8 is opened to heat the cooled medium through the temperature controller 6 until Ts- △ t- △ t1 is less than or equal to Tb and less than or equal to Ts + △ t, the operation state of the load is readjusted according to the control logic of the host to reduce the cooling output, preferably △ t is 0.5 ℃ and △ t1 is 0.5 ℃.
The optimal control mode is that Tb < Ts- △ t- △ t1 shows that the inlet temperature of the cooled medium is less than the error range of the target set value, and the temperature of the cooled medium needs to be heated, and at the moment, the air valve is opened to realize the effect of heating the cooled medium by the refrigerant in the temperature controller, so as to realize the function of accurately controlling the temperature of the medium.
Preferably, the first and second electrodes are formed of a metal,
judging whether the outlet temperature Ta of the cooling medium meets Ts- △ t and does not exceed △ t, and if so, maintaining the opening of the existing air valve;
when Ts-Ta is larger than △ t, the opening degree of the air valve is increased, the larger the difference between Ts-Ta is, until Ta reaches- △ t which is not less than Ts-Ta which is not less than △ t, and at the moment, the opening degree of the air valve is maintained;
when Ts-Ta < - △ t, the air valve is closed, and at least one of the frequency increase of the compressor, the opening degree increase of the electronic expansion valve and the rotation speed increase of the condensation fan is adjusted to increase the refrigerating capacity.
The invention is a preferable control mode for controlling according to the outlet temperature of the cooling medium, namely- △ t is less than or equal to Ts-Ta is less than or equal to △ t, which indicates that when the outlet temperature is within a target set temperature error range, the opening degree of the air valve is kept unchanged, the medium is continuously heated in the state, Ts-Ta is more than △ t, which indicates that the outlet temperature of the medium is too low, and at the moment, the heating quantity of the medium is increased, the opening degree of the air valve is in direct proportion to the temperature difference (Ts-Ta) and can quickly increase the temperature of the medium, Ts-Ta < - △ t indicates that the outlet temperature of the medium is too high, at the moment, the medium is required to be stopped to heat and cooled, at the moment, the air valve is closed, and at least one of the frequency increase of the compressor, the opening degree increase of the electronic expansion valve and the rotation speed increase of the condensing fan is adjusted, so that the temperature of the medium can be effectively reduced to be within the target temperature range and meet the use requirement.
Particularly, the sensible heat exchange between the hot air and the low-temperature freezing medium on the other side is mainly performed in the temperature controller, the regulation control of the refrigerating system is not involved, and the stable operation of the refrigerating system is facilitated. The specific main control steps of the target temperature of the water system of the unit are as follows:
1) when the compressor runs, the frequency of the compressor and/or the opening of the electronic expansion valve and/or the rotating speed of the condensing fan are/is adjusted according to the set temperature Ts, the Tb is less than or equal to Ts + △ t (△ t is the temperature control precision set by a user, if the set control precision is +/-0.5 ℃, △ t is 0.5, and the rest is the same) at the fastest speed (the running parameters under the memory state are usually adopted for starting running, and the optimal running combination parameters of the organic unit under the memory state) is adopted, and when the Ts- △ t-0.5 is less than or equal to the Tb and less than or equal to Ts + △ t, the running state of the load is maintained;
2) when Tb is less than Ts- △ t-0.5, readjusting the running state of the load according to the control logic of the host to reduce the refrigerating output until Ts- △ t-0.5 is more than or equal to Tb and less than or equal to Ts + △ t is satisfied;
a) judging whether the outlet temperature Ts-Ta is less than or equal to- △ t and is less than or equal to △ t, if so, maintaining the opening of the existing air valve;
b) when Ts-Ta is larger than △ t, the opening degree of the air valve is increased, the larger the difference between Ts-Ta is, and the larger the opening degree of the air valve is, and the opening degree of the air valve is maintained until- △ t is smaller than or equal to Ts-Ta is smaller than or equal to △ t;
c) when Ts-Ta < - △ t, closing the air valve, and switching to adjust the load of the refrigeration system to increase the refrigeration capacity of the system, and entering the step 1) again.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention. The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (11)
1. A refrigerating system capable of accurately controlling the temperature of a medium is characterized in that: the method comprises the following steps:
the system comprises a compressor (1), a condenser (2), a condensing fan (21), an electronic expansion valve (3) and an evaporator (4);
a cooling medium pipeline (5) which is filled with a cooled medium, and the cooling medium pipeline (5) is communicated into the evaporator (4) to ensure that the refrigerant and the cooled medium exchange heat in the evaporator (4);
the temperature controller (6) is arranged on the cooling medium pipeline (5), and the temperature controller (6) is arranged on the air outlet side of the condensing fan (21) so as to exchange heat between hot air blown out by the condensing fan (21) and a cooled medium in the cooling medium pipeline (5) in the temperature controller (6);
the temperature controller (6) comprises an air channel (61) and an air valve (8) arranged at the inlet of the air channel (61), and the air valve (8) can control the opening and closing of the air channel (61) and adjust the opening degree; and a first temperature sensor (91) is arranged at the inlet end of the temperature controller (6) on the cooling medium pipeline (5).
2. A refrigeration system capable of accurately controlling the temperature of a medium according to claim 1, wherein:
the temperature controller (6) is arranged on the cooling medium pipeline (5) and is positioned at the downstream section of the evaporator (4) along the flow direction of the cooled medium.
3. A refrigeration system capable of accurately controlling a temperature of a medium according to any one of claims 1 to 2, wherein:
and a second temperature sensor (92) is arranged on the cooling medium pipeline (5) at the outlet end of the temperature controller (6).
4. A refrigeration system capable of accurately controlling the temperature of a medium according to claim 3, wherein:
when a first temperature sensor (91) is included, the first temperature sensor (91) is a bulb; when a second temperature sensor (92) is included, the second temperature sensor (92) is a bulb.
5. A refrigeration system capable of accurately controlling a temperature of a medium according to any one of claims 1 to 2, wherein:
the thermostat (6) is a finned heat exchanger, and the finned heat exchanger comprises a radiating pipe (62) with an annular fin on the outer wall or a radiating pipe (62) with a longitudinal fin on the outer wall, the radiating pipe (62) with the annular fin on the outer wall is arranged in the pipe axis direction perpendicular to the air outlet direction of the condensation fan, and the radiating pipe (62) with the longitudinal fin on the outer wall is arranged in the pipe axis direction parallel to the air outlet direction of the condensation fan.
6. A refrigeration system capable of accurately controlling a temperature of a medium according to any one of claims 1 to 2, wherein:
the cooled medium is water, and the water is introduced into the cooling medium pipeline (5) and passes through the evaporator (4) to be cooled, and then passes through the temperature controller (6) to be heated.
7. A control method of a refrigeration system capable of accurately controlling the temperature of a medium is characterized in that: the refrigeration system capable of accurately controlling the temperature of the medium according to any one of claims 1 to 6 is used to realize accurate control of the temperature of the medium to be cooled.
8. The control method according to claim 7, characterized in that:
when a first temperature sensor (91) and a second temperature sensor (92) are included, the first temperature sensor (91) detects that the inlet temperature of the cooling medium of the temperature controller (6) is Tb, and the second temperature sensor (92) detects that the outlet temperature of the cooling medium of the temperature controller (6) is Ta; setting the target temperature of the cooled medium to Ts;
when the refrigeration system is started, the frequency of the compressor and/or the opening of the electronic expansion valve and/or the rotating speed of the condensing fan are/is adjusted, so that the temperature Tb reaches Ts + △ t, and the accuracy △ t is a first accuracy error.
9. The control method according to claim 8, characterized in that:
and when Ts- △ t- △ t1 is not less than Tb and not more than Ts + △ t, maintaining the current operation states of the compressor, the electronic expansion valve and the condensing fan, wherein △ t1 is a second precision error.
10. The control method according to claim 8, characterized in that:
when Tb is less than Ts- △ t- △ t1 and an air valve is included, the air valve (8) is opened to heat the cooled medium through the temperature controller (6) until Ts- △ t- △ t1 is less than or equal to Tb and less than or equal to Ts + △ t.
11. The control method according to claim 10, characterized in that:
judging whether the outlet temperature Ta of the cooling medium meets Ts- △ t and does not exceed △ t, and if so, maintaining the opening of the existing air valve;
when Ts-Ta is larger than △ t, the opening degree of the air valve is increased, the larger the difference between Ts-Ta is, until Ta reaches- △ t which is not less than Ts-Ta which is not less than △ t, and at the moment, the opening degree of the air valve is maintained;
when Ts-Ta < - △ t, the air valve is closed, and at least one of the frequency increase of the compressor, the opening degree increase of the electronic expansion valve and the rotation speed increase of the condensation fan is adjusted to increase the refrigerating capacity.
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| JP7403984B2 (en) * | 2019-07-26 | 2023-12-25 | 株式会社鷺宮製作所 | Cooling system |
| CN112384040B (en) * | 2020-11-12 | 2022-05-24 | 中国电子科技集团公司第二十九研究所 | Skin heat exchange bypass control system and control method thereof |
| CN113400086B (en) * | 2021-07-01 | 2022-09-13 | 珠海格力智能装备有限公司 | Cooling system |
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| CN200958814Y (en) * | 2006-10-12 | 2007-10-10 | 南京建贸制冷空调设备有限公司 | Water-cooling and temperature-adjusting dehumidifier set |
| CN102338428A (en) * | 2010-07-26 | 2012-02-01 | 珠海格力电器股份有限公司 | Total-heat-recovery-type fresh air dehumidifier unit |
| CN202254135U (en) * | 2011-08-22 | 2012-05-30 | 珠海铨高机电设备有限公司 | Dehumidifying and reheating device of air conditioner |
| CN203837360U (en) * | 2014-05-16 | 2014-09-17 | 清华大学 | Solution-spraying-type frostless air source heat pump device |
| CN205425262U (en) * | 2016-03-18 | 2016-08-03 | 上海朗绿建筑科技有限公司 | Fresh air dehumidification unit of many condensers of single evaporimeter |
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