CN116608618A - Defrosting control method and system of condensing unit and condensing unit - Google Patents
Defrosting control method and system of condensing unit and condensing unit Download PDFInfo
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- CN116608618A CN116608618A CN202310664609.8A CN202310664609A CN116608618A CN 116608618 A CN116608618 A CN 116608618A CN 202310664609 A CN202310664609 A CN 202310664609A CN 116608618 A CN116608618 A CN 116608618A
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- 238000010257 thawing Methods 0.000 title claims abstract description 100
- 238000000034 method Methods 0.000 title claims abstract description 47
- 238000005057 refrigeration Methods 0.000 claims description 30
- 238000001514 detection method Methods 0.000 claims description 13
- 238000004590 computer program Methods 0.000 claims description 7
- 230000008859 change Effects 0.000 claims description 4
- 230000008439 repair process Effects 0.000 claims description 4
- 238000012423 maintenance Methods 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 description 31
- 230000005856 abnormality Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 239000003507 refrigerant Substances 0.000 description 4
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 238000005485 electric heating Methods 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 230000009191 jumping Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
Classifications
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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
- F25B13/00—Compression machines, plants or systems, with 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
- F25B41/24—Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
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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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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention discloses a defrosting control method, a system and a condensing unit, wherein the method detects whether the reversing of a four-way valve fails by detecting the temperature of a pipe inlet pipe and a pipe outlet pipe of an indoor evaporator at the current moment, and controls the working states of an external machine load and an internal machine load of the condensing unit after judging that the reversing of the four-way valve fails until the condensing unit successfully enters or exits a defrosting mode.
Description
Technical Field
The invention relates to the technical field of intelligent control, in particular to a defrosting control method and system of a condensing unit and the condensing unit.
Background
The main defrosting mode of the condensing unit for the refrigeration house in the current market is electric heating defrosting, and the mode is easy to cause the problems of high temperature rise of the refrigeration house, long time consumption, low efficiency, large defrosting increment, high power consumption and the like. Part of products utilize the scheme of hot gasification frost, adopt the cross valve to switch the refrigerant flow direction, realize reverse circulation defrosting. However, the condensing unit generally adopts a low-temperature refrigerant, when the ambient temperature is lower, the pressure difference between the condensing pressure and the evaporating pressure of the unit system is very low, and meanwhile, after the condensing unit is stopped, the pressure difference between the suction pressure and the exhaust pressure is quickly reduced to be close to zero, so that the four-way valve is easy to reverse, the condensing unit to be defrosted cannot enter a defrosting mode, or the condensing unit without defrosting end after defrosting is finished, and the normal use of the condensing unit is influenced.
The related art discloses a method for realizing four-way valve reversing by detecting the pressure difference between the exhaust pressure and the suction pressure and comparing and judging with a target value, and then realizing four-way valve reversing by meeting the conditions, and finally realizing four-way valve reversing by adjusting the working state of the current component for condensation work if the conditions are not met. Although the technology overcomes the problems that the four-way valve is easy to cause failure in reversing, so that a condensing unit to be defrosted cannot enter a defrosting mode, or the defrosting mode is not finished, and normal use of the condensing unit is affected. However, as the four-way valve belongs to an open-loop control component, the method does not realize closed-loop detection of whether the four-way valve is successfully commutated, and cannot thoroughly solve the actual problem of failure of the four-way valve commutation, and finally, a condensing unit cannot truly enter defrosting, so that ice blockage and system failure are caused; or failure to divert and continue heating upon exiting defrosting, causes the bank Wen Jiju to rise and destroy the contents of the bank with significant economic loss.
Disclosure of Invention
The invention aims to overcome the technical defects and provide a defrosting control method and system of a condensing unit and the condensing unit, so as to solve the problem that the condensing unit to be defrosted cannot enter a defrosting mode or the condensing unit after defrosting is not in an ending defrosting mode and normal use of the condensing unit is affected due to failure of reversing of a four-way valve in the related technology.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
according to a first aspect of the present invention, there is provided a defrosting control method of a condensing unit, comprising:
detecting the working mode of a condensing unit;
if the current working mode is a refrigeration mode or a defrosting mode, detecting the pipe inlet temperature of the indoor evaporator at the current moment and the pipe outlet temperature of the indoor evaporator at the current moment;
judging whether the four-way valve of the condensing unit fails to commutate at the current moment according to the temperature of the inlet pipe and the outlet pipe, and controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode when judging that the four-way valve fails to commutate.
Preferably, the judging whether the four-way valve of the condensing unit fails in reversing at the current moment according to the pipe inlet pipe temperature and the pipe outlet pipe temperature includes:
if the current working mode is a refrigeration mode and the difference value between the outlet pipe temperature and the inlet pipe temperature is larger than a first preset value, judging that the four-way valve fails to commutate;
if the current working mode is a defrosting mode and the difference value between the inlet pipe temperature and the outlet pipe temperature is larger than a second preset value, judging that the four-way valve fails to change.
Preferably, when the judging that the four-way valve fails in reversing, controlling the working states of an external machine load and an internal machine load of the condensing unit includes:
if the current working mode is a refrigeration mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, keeping an internal fan in an internal machine load running, and accumulating the reversing failure times of the four-way valve;
after a first preset time length, acquiring the internal environment temperature of an internal machine of the condensing unit in a warehouse;
if the internal temperature in the warehouse is smaller than the preset warehouse temperature alarm temperature and the reversing times of the four-way valve are smaller than the first preset times, controlling the internal fan to keep running, and starting a compressor, an external fan and an electronic expansion valve in an external machine load;
after the air suction and exhaust pressure difference at two ends of a piston in the four-way valve reaches a reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to enter a defrosting mode;
and in the defrosting mode, when the suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference again, controlling the four-way valve to be powered off, exiting the defrosting mode, and returning to the refrigerating mode.
Preferably, the method further comprises:
if the current working mode is a refrigeration mode and the four-way valve fails in commutation, defining four-way valve failure fault information as a primary manufacturer-level fault and synchronously reporting the primary manufacturer-level fault to manufacturers; and/or the number of the groups of groups,
if the current working mode is a refrigeration mode and the internal environment temperature in the warehouse is greater than or equal to the preset warehouse temperature alarm temperature, the four-way valve reversing failure fault information is defined as a first-level user-level fault, the whole condensing unit is controlled to stop running, and a user is synchronously reminded of maintenance or repair.
Preferably, when the judging that the four-way valve fails in reversing, controlling the working states of an external machine load and an internal machine load of the condensing unit further includes:
if the current working mode is a defrosting mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, and keeping an internal fan in an internal machine load to run;
after a second preset time period, controlling the inner fan to keep running, and starting a compressor, an outer fan and an electronic expansion valve in an outer machine load;
and after the air suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to exit the defrosting mode.
Preferably, the method further comprises:
and if the current working mode is a defrosting mode, and the four-way valve fails in reversing, accumulating the reversing failure times of the four-way valve, defining the reversing failure information of the four-way valve as a secondary manufacturer-level failure, and synchronously reporting the two-level failure information to manufacturers.
Preferably, the method further comprises:
starting timing from the four-way valve reversing end moment, and calculating the reversing time length from the four-way valve reversing end moment to the current moment;
if the reversing time length exceeds the threshold value range, judging that the current four-way valve reversing failure fault is an accidental fault, and resetting the accumulated four-way valve reversing fault times.
Preferably, the method further comprises:
when the condensing unit is powered on and started for the first time, timing is started from the starting moment of the compressor by default.
Preferably, the detecting the working mode of the condensing unit specifically includes:
and after the condensing unit is started, detecting the working mode of the condensing unit if the reversing time is longer than the preset reversing time of the four-way valve.
According to a second aspect of the present invention, there is provided a defrosting control system of a condensing unit, comprising:
the first detection module is used for detecting the working mode of the condensing unit;
the second detection module is used for detecting the pipe inlet temperature of the indoor evaporator at the current moment and the pipe outlet temperature of the indoor evaporator at the current moment if the current working mode is a refrigeration mode or a defrosting mode;
and the control module is used for judging whether the four-way valve of the condensing unit fails to commutate at the current moment according to the temperature of the inlet pipe and the outlet pipe, and controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode when judging that the four-way valve fails to commutate.
According to a third aspect of the present invention, there is provided a condensing unit comprising:
a processor and a memory coupled to the processor;
the memory is used for storing a computer program;
the processor is configured to invoke and execute the computer program in the memory to perform the method described above.
The technical scheme provided by the embodiment of the invention can comprise the following beneficial effects:
by detecting the temperature of the inlet pipe and the outlet pipe of the indoor evaporator at the current moment, whether the four-way valve is failed to commutate is detected, and after the four-way valve is judged to commutate failure, the working states of the external machine load and the internal machine load of the condensing unit are controlled until the condensing unit successfully enters or exits the defrosting mode.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.
Drawings
FIG. 1 is a flow chart illustrating a method of controlling defrosting of a condensing unit, according to an exemplary embodiment;
FIG. 2 is a flow chart illustrating a defrost control method for a condensing unit, according to another exemplary embodiment;
FIG. 3 is a schematic block diagram illustrating a defrost control system for a condensing unit in accordance with an exemplary embodiment.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
As described in the foregoing background art, in the related art, there is a problem that the four-way valve fails to commutate, so that the condensing unit to be defrosted cannot enter the defrosting mode, or the condensing unit after defrosting is finished does not have the defrosting mode, which affects the normal use of the condensing unit.
In order to effectively solve the problems in the related art, the invention provides a defrosting control method and system of a condensing unit and the condensing unit, and the defrosting control method and system are specifically described below.
Example 1
Fig. 1 is a flowchart illustrating a defrosting control method of a condensing unit according to an exemplary embodiment, and as shown in fig. 1, the method includes:
s11, detecting the working mode of a condensing unit;
step S12, if the current working mode is a refrigeration mode or a defrosting mode, detecting the pipe inlet temperature of the indoor evaporator at the current moment and the pipe outlet temperature of the indoor evaporator at the current moment;
and S13, judging whether the four-way valve of the condensing unit fails to commutate at the current moment according to the temperature of the inlet pipe and the outlet pipe, and controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode when judging that the four-way valve fails to commutate.
It should be noted that, in the technical solution provided in this embodiment, the load is operated in a controller of the condensing unit in specific practice, or the load is operated in an electronic device connected to the controller. The controller includes, but is not limited to: PLC controller, singlechip, ARM processor, DSP processor, FPGA controller etc..
The reverse circulation defrosting method is a common defrosting method, has low cost and simple realization, so the reverse circulation defrosting method gradually replaces electric heating defrosting and is applied to various condensing units. The four-way valve is an important part for realizing reverse circulation defrosting, and the four-way valve realizes automatic reversing of evaporation and condensation of the heat exchanger based on pressure difference at two ends of the piston, so that the evaporator to be defrosted is converted into a condenser to realize thermal defrosting, and the four-way valve is reversed again to restore the normal refrigeration mode of the evaporator after defrosting is finished, and the temperature difference exists between the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator due to the flow direction difference of the refrigerant in the refrigeration and defrosting modes.
It can be appreciated that, the technical scheme provided by this embodiment detects whether the four-way valve is failed to reverse by detecting the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator at the current moment, and after judging that the four-way valve is failed to reverse, controls the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode.
In specific practice, in step S11, the working mode of the condensing unit is detected, specifically:
and after the condensing unit is started, detecting the working mode of the condensing unit if the reversing time delta t of the four-way valve is longer than the preset reversing time ta of the four-way valve.
It should be noted that, the preset commutation duration ta is set according to a historical empirical value or experimental data. It can be understood that if the reversing time Δt of the four-way valve is greater than the preset reversing time ta of the four-way valve, it is indicated that the four-way valve may have a reversing fault at present, so that the working mode of the condensing unit is detected and controlled according to the working mode on the premise, so that the calculation amount of the system is reduced, the judging and calculating processes are reduced, the system computing resource is saved, and the system response speed is improved.
In specific practice, starting timing from the four-way valve reversing end moment, and calculating the reversing time delta t of the four-way valve reversing end moment from the current moment;
if the commutation duration Δt exceeds a threshold range (the threshold range is set according to historical empirical values or experimental data, for example, is set to be greater than 1 hour and less than 2 hours), determining that the current fault of the four-way valve commutation failure is an accidental fault, and resetting the accumulated four-way valve commutation failure times.
Specifically, when the condensing unit is powered on and started for the first time, timing is started from the starting moment of the compressor by default.
In specific practice, in step S13, according to the pipe inlet pipe temperature and the pipe outlet pipe temperature, it is determined whether the four-way valve of the condensing unit fails in reversing at the current moment, including:
if the current working mode is a refrigeration mode and the difference between the outlet pipe temperature Ti-c and the inlet pipe temperature Ti-j is larger than a first preset value Ta (namely, (Ti-c) - (Ti-j) > Ta), judging that the four-way valve fails in reversing;
if the current working mode is a defrosting mode and the difference between the inlet pipe temperature Ti-j and the outlet pipe temperature Ti-c is larger than a second preset value Tb (namely, (Ti-j) - (Ti-c) > Tb), judging that the four-way valve fails in reversing.
It should be noted that Ta and Tb are set according to historical empirical values or experimental data. In order to improve the detection precision of the four-way valve commutation failure, the corresponding in-library environment temperature range under different working modes can be subdivided into a plurality of different Ta and Tb values corresponding to different ranges, so that the detection is more accurate.
It should be noted that, in other working modes or when the four-way valve is judged to be successfully commutated, the condensing unit keeps the current working state unchanged;
further, when it is determined in step S13 that the four-way valve fails to commutate, the working states of the external machine load and the internal machine load of the condensing unit are controlled, including:
if the current working mode is a refrigeration mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, keeping an internal fan in the internal machine load running, and accumulating the reversing failure times of the four-way valve (namely Ca=Ca+1, ca is the failure times of the four-way valve);
after a first preset time length, acquiring the internal environment temperature Ti-h of an internal machine of the condensing unit;
if the internal environment temperature Ti-h is smaller than the preset internal temperature alarm temperature Tbj (namely (Ti-h) < Tbj), and the four-way valve reversing times are smaller than the first preset times (namely Ca is smaller than or equal to n1 and n1 is acquired according to historical experience values or experimental data), controlling the internal fan to keep running, and starting a compressor, an external fan and an electronic expansion valve in an external load;
after the air suction and exhaust pressure difference at two ends of a piston in the four-way valve reaches a reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to enter a defrosting mode;
and in the defrosting mode, when the suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference again, controlling the four-way valve to be powered off, exiting the defrosting mode, and returning to the refrigerating mode.
It should be noted that the first preset duration is a minimum value t of a preset time for restarting the four-way valve in a reversing failure in the refrigeration mode b min, the first preset time length is set according to historical experience values or experimental data.
External machine loads include, but are not limited to: a compressor, an external fan, an electronic expansion valve, etc.
Preferably, the method further comprises:
if the current working mode is a refrigeration mode and the four-way valve fails in commutation, defining four-way valve failure fault information as a primary manufacturer-level fault S1 and synchronously reporting the primary manufacturer-level fault S1 to manufacturers; and/or the number of the groups of groups,
if the current working mode is a refrigeration mode, and the internal environment temperature Ti-h is more than or equal to the preset internal temperature alarm temperature Tbj (namely (Ti-h) is more than or equal to Tbj), the four-way valve reversing failure fault information is defined as a primary user-level fault R1, the whole condensing unit is controlled to stop running, and a user is synchronously reminded of maintenance or repair.
It can be understood that under the refrigeration mode, the failure of reversing the four-way valve can lead to the rapid rise of the temperature in the warehouse, the temperature in the warehouse is lower than the preset warehouse temperature alarm temperature, the valve pushing can be continuously tried, the temperature in the warehouse is higher than the preset warehouse temperature alarm temperature, the emergency stop is carried out, and the user is reminded to report or solve the problem. Unnecessary fault shutdown and risk fault timely shutdown are reduced through hierarchical control, reliability of the unit can be exerted to the greatest extent under severe working conditions, and stability and reliability of a system are improved.
In specific practice, when it is determined in step S13 that the four-way valve fails to commutate, the working states of the external machine load and the internal machine load of the condensing unit are controlled, and the method further includes:
if the current working mode is a defrosting mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, and keeping an internal fan in an internal machine load to run;
after a second preset time period, controlling the inner fan to keep running, and starting a compressor, an outer fan and an electronic expansion valve in an outer machine load;
and after the air suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to exit the defrosting mode.
It should be noted that the second preset duration is a minimum value t of the restart preset time of the four-way valve commutation failure in the defrosting mode c min, setting a second preset time length according to historical experience values or experimental data.
External machine loads include, but are not limited to: a compressor, an external fan, an electronic expansion valve, etc.
Preferably, the method further comprises:
if the current working mode is a defrosting mode, and the four-way valve fails in reversing, the four-way valve reversing failure times are accumulated (namely Ca=Ca+1, ca is the four-way valve reversing failure times), and the four-way valve reversing failure information is defined as a secondary manufacturer grade failure S2 and synchronously reported to manufacturers.
It should be noted that, the commutation failure fault S1 in the refrigeration mode and the commutation failure fault S2 in the defrosting mode are both manufacturer-level faults, and the condensing unit has no influence on the user temporarily in the fault state; the commutation fails in the refrigeration mode, the internal environment temperature in the warehouse exceeds the warehouse temperature alarm temperature, and the user-level fault R1 is reported, and the fault state has influence on the use of a user or brings economic loss to the user, so that the user needs to be reminded in time.
It can be understood that under the defrosting mode, the influence of the reversing failure of the four-way valve on the stored articles in the warehouse is small, and under the condition that the internal fan can be kept on, the compressor system intermittently works to achieve the defrosting purpose (the external load of the condensing unit is controlled to stop and reset, the compressor stops working at the moment, after the second preset time period, the compressor, the external fan and the electronic expansion valve in the external load are started, and the compressor is started to work at the moment), so that the lower temperature in the warehouse is ensured. Unnecessary fault shutdown and risk fault timely shutdown are reduced through hierarchical control, reliability of the unit can be exerted to the greatest extent under severe working conditions, and stability and reliability of a system are improved.
It will be appreciated that in particular practice, the failure of the four-way valve to commutate is caused by a variety of reasons, such as, for example, the four-way valve commutating voltage being too low, the system or components being accidentally abnormal, etc.
It can be appreciated that, according to the technical scheme provided by the embodiment, by detecting the difference value between the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator in the refrigeration mode and the defrosting mode, and comparing the difference value with the preset value, the detection of whether the four-way valve is failed in reversing is realized, then the unit is further controlled according to the detection result, and the problems of the four-way valve failure caused by too low voltage, occasional abnormality of a system or a component and the like are solved by trying to push the valve for several times. According to the technical scheme provided by the embodiment, the four-way valve is monitored in real time in a reversing manner, the external machine load and the internal machine load are regulated and controlled according to monitoring abnormality, the beneficial effect of the unit is maximized, unnecessary fault shutdown and risk fault timely shutdown are reduced through hierarchical control, the reliability of the unit can be furthest exerted under severe working conditions, and the stability and the reliability of a system are improved.
Example two
Fig. 2 is a flowchart illustrating a defrosting control method of a condensing unit according to another exemplary embodiment, as shown in fig. 2, the method including:
step S21, when the condensing unit is electrified and started for the first time, starting timing from the starting moment of the compressor by default, otherwise, starting timing from the reversing end moment of the four-way valve, and calculating the reversing time length from the reversing end moment of the four-way valve to the current moment;
step S22, if the reversing time length exceeds a threshold value range, judging that the current four-way valve reversing failure fault is an accidental fault, and resetting the accumulated four-way valve reversing fault times;
step S23, detecting the working mode of the condensing unit if the reversing time length is longer than the preset reversing time length of the four-way valve;
step S24, if the current working mode is a refrigeration mode, and the difference value between the outlet pipe temperature and the inlet pipe temperature is larger than a first preset value, judging that the four-way valve fails to commutate, and jumping to the step S27;
step S25, if the current working mode is a defrosting mode, and the difference value between the inlet pipe temperature and the outlet pipe temperature is larger than a second preset value, judging that the four-way valve fails to commutate, and jumping to step S28;
step S26, under other working modes or when the four-way valve is judged to be successfully commutated, the condensing unit keeps the current working state unchanged;
step S27, controlling the working states of an external machine load and an internal machine load of the condensing unit until the condensing unit successfully enters and exits a defrosting mode, wherein the method comprises the following steps:
controlling the outer machine load of the condensing unit to stop and reset, keeping an inner fan in the inner machine load to run, and accumulating the reversing failure times of the four-way valve; the four-way valve commutation failure fault information is defined as a first-level manufacturer-level fault and synchronously reported to manufacturers;
after a first preset time length, acquiring the internal environment temperature of an internal machine of the condensing unit in a warehouse;
if the internal temperature in the warehouse is smaller than the preset warehouse temperature alarm temperature and the reversing times of the four-way valve are smaller than the first preset times, controlling the internal fan to keep running, and starting a compressor, an external fan and an electronic expansion valve in an external machine load; if the internal environment temperature in the warehouse is greater than or equal to the preset warehouse temperature alarm temperature, defining the four-way valve reversing failure fault information as a first-level user-level fault, controlling the whole condensing unit to stop running, and synchronously reminding a user to maintain or repair;
after the air suction and exhaust pressure difference at two ends of a piston in the four-way valve reaches a reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to enter a defrosting mode;
and in the defrosting mode, when the suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference again, controlling the four-way valve to be powered off, exiting the defrosting mode, and returning to the refrigerating mode.
Step S28, controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully exits the defrosting mode, wherein the method comprises the following steps:
if the current working mode is a defrosting mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, and keeping an internal fan in an internal machine load to run; the four-way valve reversing failure times are accumulated, the four-way valve reversing failure information is defined as a secondary manufacturer level failure, and the two-way valve reversing failure information is synchronously reported to manufacturers;
after a second preset time period, controlling the inner fan to keep running, and starting a compressor, an outer fan and an electronic expansion valve in an outer machine load;
and after the air suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to exit the defrosting mode.
It should be noted that, in the technical solution provided in this embodiment, the load is operated in a controller of the condensing unit in specific practice, or the load is operated in an electronic device connected to the controller. The controller includes, but is not limited to: PLC controller, singlechip, ARM processor, DSP processor, FPGA controller etc..
It can be appreciated that, according to the technical scheme provided by the embodiment, by detecting the difference value between the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator in the refrigeration mode and the defrosting mode, and comparing the difference value with the preset value, the detection of whether the four-way valve is failed in reversing is realized, then the unit is further controlled according to the detection result, and the problems of the four-way valve failure caused by too low voltage, occasional abnormality of a system or a component and the like are solved by trying to push the valve for several times. According to the technical scheme provided by the embodiment, the four-way valve is monitored in real time in a reversing manner, the external machine load and the internal machine load are regulated and controlled according to monitoring abnormality, the beneficial effect of the unit is maximized, unnecessary fault shutdown and risk fault timely shutdown are reduced through hierarchical control, the reliability of the unit can be furthest exerted under severe working conditions, and the stability and the reliability of a system are improved.
Example III
Fig. 3 is a schematic block diagram of a defrosting control system 100 of a condensing unit, according to an exemplary embodiment, as shown in fig. 3, the system 100 includes:
a first detection module 101, configured to detect an operation mode of the condensing unit;
the second detection module 102 is configured to detect a tube inlet temperature of the indoor evaporator at the current moment and a tube outlet temperature of the indoor evaporator at the current moment if the current working mode is a cooling mode or a defrosting mode;
and the control module 103 is used for judging whether the four-way valve of the condensing unit fails to change direction at the current moment according to the temperature of the inlet pipe and the outlet pipe, and controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode when judging that the four-way valve fails to change direction.
It should be noted that, in the technical solution provided in this embodiment, the load is operated in a controller of the condensing unit in specific practice, or the load is operated in an electronic device connected to the controller. The controller includes, but is not limited to: PLC controller, singlechip, ARM processor, DSP processor, FPGA controller etc..
The implementation manner and the beneficial effects of the above modules refer to the description of the related steps of the above embodiment, and this embodiment is not repeated.
The reverse circulation defrosting method is a common defrosting method, has low cost and simple realization, so the reverse circulation defrosting method gradually replaces electric heating defrosting and is applied to various condensing units. The four-way valve is an important part for realizing reverse circulation defrosting, and the four-way valve realizes automatic reversing of evaporation and condensation of the heat exchanger based on pressure difference at two ends of the piston, so that the evaporator to be defrosted is converted into a condenser to realize thermal defrosting, and the four-way valve is reversed again to restore the normal refrigeration mode of the evaporator after defrosting is finished, and the temperature difference exists between the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator due to the flow direction difference of the refrigerant in the refrigeration and defrosting modes.
It can be appreciated that, the technical scheme provided by this embodiment detects whether the four-way valve is failed to reverse by detecting the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator at the current moment, and after judging that the four-way valve is failed to reverse, controls the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode.
Example IV
A condensing unit is shown according to an exemplary embodiment, comprising:
a processor and a memory coupled to the processor;
the memory is used for storing a computer program;
the processor is configured to invoke and execute the computer program in the memory to perform the method described above.
It can be appreciated that, the technical scheme provided by this embodiment detects whether the four-way valve is failed to reverse by detecting the inlet pipe temperature and the outlet pipe temperature of the indoor evaporator at the current moment, and after judging that the four-way valve is failed to reverse, controls the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode.
Of course, those skilled in the art will appreciate that implementing all or part of the above-described methods may be implemented by a computer program for instructing relevant hardware (e.g., a processor, a controller, etc.), where the program may be stored in a computer-readable storage medium, and where the program may include the steps of the above-described method embodiments when executed. The storage medium may be a memory, a magnetic disk, an optical disk, or the like.
The above-described embodiments of the present invention do not limit the scope of the present invention. Any other corresponding changes and modifications made in accordance with the technical idea of the present invention shall be included in the scope of the claims of the present invention.
Claims (11)
1. The defrosting control method of the condensing unit is characterized by comprising the following steps of:
detecting the working mode of a condensing unit;
if the current working mode is a refrigeration mode or a defrosting mode, detecting the pipe inlet temperature of the indoor evaporator at the current moment and the pipe outlet temperature of the indoor evaporator at the current moment;
judging whether the four-way valve of the condensing unit fails to commutate at the current moment according to the temperature of the inlet pipe and the outlet pipe, and controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode when judging that the four-way valve fails to commutate.
2. The method of claim 1, wherein the determining whether the four-way valve of the condensing unit fails to reverse at the current moment according to the pipe inlet pipe temperature and the pipe outlet pipe temperature comprises:
if the current working mode is a refrigeration mode and the difference value between the outlet pipe temperature and the inlet pipe temperature is larger than a first preset value, judging that the four-way valve fails to commutate;
if the current working mode is a defrosting mode and the difference value between the inlet pipe temperature and the outlet pipe temperature is larger than a second preset value, judging that the four-way valve fails to change.
3. The method according to claim 2, wherein when the four-way valve commutation failure is determined, controlling the working states of the external machine load and the internal machine load of the condensing unit includes:
if the current working mode is a refrigeration mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, keeping an internal fan in an internal machine load running, and accumulating the reversing failure times of the four-way valve;
after a first preset time length, acquiring the internal environment temperature of an internal machine of the condensing unit in a warehouse;
if the internal temperature in the warehouse is smaller than the preset warehouse temperature alarm temperature and the reversing times of the four-way valve are smaller than the first preset times, controlling the internal fan to keep running, and starting a compressor, an external fan and an electronic expansion valve in an external machine load;
after the air suction and exhaust pressure difference at two ends of a piston in the four-way valve reaches a reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to enter a defrosting mode;
and in the defrosting mode, when the suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference again, controlling the four-way valve to be powered off, exiting the defrosting mode, and returning to the refrigerating mode.
4. A method according to claim 3, further comprising:
if the current working mode is a refrigeration mode and the four-way valve fails in commutation, defining four-way valve failure fault information as a primary manufacturer-level fault and synchronously reporting the primary manufacturer-level fault to manufacturers; and/or the number of the groups of groups,
if the current working mode is a refrigeration mode and the internal environment temperature in the warehouse is greater than or equal to the preset warehouse temperature alarm temperature, the four-way valve reversing failure fault information is defined as a first-level user-level fault, the whole condensing unit is controlled to stop running, and a user is synchronously reminded of maintenance or repair.
5. The method of claim 3, wherein when the four-way valve commutation failure is determined, controlling the working states of the external machine load and the internal machine load of the condensing unit, further comprises:
if the current working mode is a defrosting mode and the four-way valve fails in reversing, controlling an external machine load of the condensing unit to stop and reset, and keeping an internal fan in an internal machine load to run;
after a second preset time period, controlling the inner fan to keep running, and starting a compressor, an outer fan and an electronic expansion valve in an outer machine load;
and after the air suction and exhaust pressure difference at two ends of the piston in the four-way valve reaches the reversing pressure difference, controlling the four-way valve to be electrified and reversed so as to exit the defrosting mode.
6. The method as recited in claim 5, further comprising:
and if the current working mode is a defrosting mode, and the four-way valve fails in reversing, accumulating the reversing failure times of the four-way valve, defining the reversing failure information of the four-way valve as a secondary manufacturer-level failure, and synchronously reporting the two-level failure information to manufacturers.
7. The method according to any one of claims 3 to 6, further comprising:
starting timing from the four-way valve reversing end moment, and calculating the reversing time length from the four-way valve reversing end moment to the current moment;
if the reversing time length exceeds the threshold value range, judging that the current four-way valve reversing failure fault is an accidental fault, and resetting the accumulated four-way valve reversing fault times.
8. The method as recited in claim 7, further comprising:
when the condensing unit is powered on and started for the first time, timing is started from the starting moment of the compressor by default.
9. The method according to claim 7, wherein the detecting the operation mode of the condensing unit comprises:
and after the condensing unit is started, detecting the working mode of the condensing unit if the reversing time is longer than the preset reversing time of the four-way valve.
10. A defrosting control system of a condensing unit, comprising:
the first detection module is used for detecting the working mode of the condensing unit;
the second detection module is used for detecting the pipe inlet temperature of the indoor evaporator at the current moment and the pipe outlet temperature of the indoor evaporator at the current moment if the current working mode is a refrigeration mode or a defrosting mode;
and the control module is used for judging whether the four-way valve of the condensing unit fails to commutate at the current moment according to the temperature of the inlet pipe and the outlet pipe, and controlling the working states of the external machine load and the internal machine load of the condensing unit until the condensing unit successfully enters or exits the defrosting mode when judging that the four-way valve fails to commutate.
11. A condensing unit, comprising:
a processor and a memory coupled to the processor;
the memory is used for storing a computer program;
the processor is configured to invoke and execute the computer program in the memory to perform the method of any of claims 1-9.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310664609.8A CN116608618A (en) | 2023-06-06 | 2023-06-06 | Defrosting control method and system of condensing unit and condensing unit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310664609.8A CN116608618A (en) | 2023-06-06 | 2023-06-06 | Defrosting control method and system of condensing unit and condensing unit |
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| CN202310664609.8A Pending CN116608618A (en) | 2023-06-06 | 2023-06-06 | Defrosting control method and system of condensing unit and condensing unit |
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| CN (1) | CN116608618A (en) |
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