CN113865167A - Anti-freezing control method for water chilling unit - Google Patents
Anti-freezing control method for water chilling unit Download PDFInfo
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- CN113865167A CN113865167A CN202111229977.7A CN202111229977A CN113865167A CN 113865167 A CN113865167 A CN 113865167A CN 202111229977 A CN202111229977 A CN 202111229977A CN 113865167 A CN113865167 A CN 113865167A
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- evaporation temperature
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- freezing
- compressor
- chilling unit
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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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- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
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- General Engineering & Computer Science (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention relates to a water chilling unit anti-freezing control method, wherein the water chilling unit is controlled in a refrigerant water anti-freezing way in operation by adopting an energy regulation way with variable feedback parameters, the output of refrigerating capacity is automatically reduced when the risk of refrigerant water freezing occurs, the refrigerant water freezing fault is fundamentally prevented by keeping the evaporation temperature above 0 ℃, the water chilling unit is not required to be protected and stopped, the continuous operation of the water chilling unit is ensured to the maximum extent, and the maintenance workload of personnel is reduced.
Description
Technical Field
The invention relates to a marine air conditioning technology, in particular to a water chilling unit anti-freezing control method.
Background
When the conditions such as sudden drop of system load or sudden drop of refrigerant water flow caused by dirty blockage of the evaporator occur in the running process of the water chilling unit, the evaporator is easy to freeze, and particularly the risk of the fault of the water chilling unit adopting a plate-type evaporator is higher. At present, the most widely applied mode is a mode of setting a temperature controller or a flow switch, and when the temperature of the outlet water of the refrigerant water is lower than 3 ℃ or the flow rate of the refrigerant water is lower than a protection value, the protection switch acts to stop the running of the water chilling unit.
Through retrieval, the anti-freezing technical research of the water chilling unit is published on the 6 th building energy conservation in 2013 by the circumgyration, various anti-freezing protection methods of the current water chilling unit are reviewed, and meanwhile, the document analyzes that the water side protection has the defect of temperature perception lag.
Disclosure of Invention
Aiming at the anti-freezing problem of the marine water chilling unit, the anti-freezing control method of the water chilling unit is provided, the evaporation temperature of the refrigerant in the evaporator is comprehensively sensed, the self energy adjusting function of the water chilling unit control system is utilized, the evaporation temperature of the refrigerant is controlled to be higher than 0 ℃ during operation, and the risk of freezing of refrigerant water of the water chilling unit is fundamentally inhibited.
The technical scheme of the invention is as follows: an anti-freezing control method for a water chilling unit is based on the suction pressure P of a refrigeration system of the water chilling unit in real timeaCalculating an evaporation temperature t, and when the evaporation temperature t is reduced to be less than or equal to 1 ℃, switching a feedback signal and a set value of an energy regulation control loop of the compressor to an anti-freezing control mode by a mode switch, wherein the evaporation temperature t is used as the feedback signal in the anti-freezing control mode, the evaporation temperature is controlled by reducing the refrigerating output, and the set control reference value of the evaporation temperature t is 1 ℃; when the evaporation temperature t rises to be higher than 3 ℃, the mode switch switches the feedback signal and the set value of the energy regulation control loop of the compressor to the normal mode, and the refrigeration quantity control mode is resumed by taking the outlet water temperature of the refrigerant water as feedback.
Further, the specific method of the anti-freezing control mode is as follows: when the refrigerating output of the compressor is more than or equal to 50 percent, namely the adjustable proportion psi is more than or equal to 50 percent, the evaporating temperature t is taken as a feedback signal, the refrigerating output is reduced by unloading the adjustable slide valve of the compressor to control the evaporating temperature, and the evaporating temperature is controlled to be more than 1 ℃; when the compressor can adjust the slide valve to unload to reduce the output of the compressor to less than 50%, the adjustment of the compressor can be stopped, namely, the adjustment proportion psi is less than 50%, the valve position is kept unchanged, if the evaporation temperature t is still continuously reduced, the hot gas bypass electronic expansion valve is opened, the evaporation temperature t is taken as a feedback signal, the opening degree of the hot gas bypass electronic expansion valve is used for continuously adjusting the reduction of the refrigeration capacity of the compressor so as to control the evaporation temperature to be more than 1 ℃.
Further, the compressor can adjust the slide valve in a PWM adjusting mode of PID control in the anti-freezing mode so as to improve the response speed of control, and the hot gas bypass electronic expansion valve is controlled by PID.
Further, the calculation formula for calculating the evaporation temperature t according to the suction pressure Pa of the refrigeration system of the water chilling unit is as follows:
t＝a3Pa 3+a2Pa 2+a1Pa-a0，
in the formula a0～a3And fitting coefficients of a polynomial for the evaporation temperature t, and obtaining the coefficient by acquiring parameters of the evaporation temperature and the suction pressure of the water chilling unit and fitting the parameters by a linear regression method.
The invention has the beneficial effects that: according to the anti-freezing control method for the water chilling unit, the water chilling unit is subjected to refrigerant water anti-freezing control in a variable feedback parameter energy adjusting mode during operation, the refrigerating output is automatically reduced when the risk of refrigerant water freezing occurs, the refrigerant water freezing fault is fundamentally prevented by keeping the evaporation temperature above 0 ℃, the water chilling unit is not required to be protected and shut down, the continuous operation of the water chilling unit is guaranteed to the maximum extent, and the maintenance workload of personnel is reduced.
Drawings
Fig. 1 is a schematic diagram of an anti-freezing control method of a water chilling unit.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
As shown in the schematic diagram of the anti-freezing control method of the water chilling unit in fig. 1, a PLC program is used for real-time controlling the anti-freezing of the water chilling unit according to the suction pressure P of the refrigeration system of the water chilling unitaCalculating the evaporation temperature t when the evaporation temperature t is lowerWhen the temperature is reduced to be less than or equal to 1 ℃, the mode switch switches the feedback signal and the set value of the energy regulation control loop of the compressor to an anti-freezing control mode which is as follows: when the refrigerating output of the compressor is more than or equal to 50 percent, namely the adjustable proportion psi is more than or equal to 50 percent, the evaporating temperature t is taken as a feedback signal in the anti-freezing control mode, the refrigerating output is reduced by unloading the sliding valve through the compressor function, and the evaporating temperature is controlled to be more than 0 ℃; when the compressor can adjust the slide valve to unload to reduce the output of the compressor to less than 50%, the adjustment of the compressor can be stopped, namely, the adjustment proportion psi is less than 50%, the valve position is kept unchanged, if the evaporation temperature t is still continuously reduced, the hot gas bypass electronic expansion valve is opened, the evaporation temperature t is taken as a feedback signal, the opening degree of the hot gas bypass electronic expansion valve is used for continuously adjusting the reduction of the refrigeration capacity of the compressor so as to control the evaporation temperature to be more than 0 ℃. In the anti-freezing mode, the compressor can regulate the slide valve in a PID control PWM regulation mode to improve the response speed of control, and the hot gas bypass electronic expansion valve is controlled in a PID mode. The evaporation temperature t is set as a control reference value and is fixed to be 1 ℃ due to the consideration of the fluctuation of the controlled parameter, so that the evaporation temperature is not lower than 0 ℃ due to the fluctuation in the control process.
When the evaporation temperature t rises to be higher than 3 ℃, the mode switch switches the feedback signal and the set value of the control loop of the slide valve of the compressor to the normal mode, and the refrigeration quantity control mode is resumed by taking the outlet water temperature of the refrigerant water as feedback. In fig. 1, the cooling amount control mode is identified by logical switching, but the specific control index is not identified.
A Programmable Logic Controller (PLC) is adopted as a control system of the water chilling unit, and a sensor is arranged to acquire suction pressure P of a refrigerating system of the water chilling unitaCalculating the real-time evaporation temperature t of the water chilling unit according to the following formula,
t＝a3Pa 3+a2Pa 2+a1Pa-a0，
in the formula a0～a3Fitting the coefficient of a polynomial for the evaporation temperature t, and obtaining the coefficient by acquiring the evaporation temperature and the suction pressure parameters of the water chilling unit and fitting by a linear regression method。
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (4)
1. The anti-freezing control method of the water chilling unit is characterized by comprising the step of controlling the anti-freezing control of the water chilling unit in real time according to the suction pressure P of a refrigeration system of the water chilling unitaCalculating an evaporation temperature t, and when the evaporation temperature t is reduced to be less than or equal to 1 ℃, switching a feedback signal and a set value of an energy regulation control loop of the compressor to an anti-freezing control mode by a mode switch, wherein the evaporation temperature t is used as the feedback signal in the anti-freezing control mode, the evaporation temperature is controlled by reducing the refrigerating output, and the set control reference value of the evaporation temperature t is 1 ℃; when the evaporation temperature t rises to be higher than 3 ℃, the mode switch switches the feedback signal and the set value of the energy regulation control loop of the compressor to the normal mode, and the refrigeration quantity control mode is resumed by taking the outlet water temperature of the refrigerant water as feedback.
2. The water chilling unit anti-freezing control method according to claim 1, wherein the anti-freezing control mode is as follows: when the refrigerating output of the compressor is more than or equal to 50 percent, namely the adjustable proportion psi is more than or equal to 50 percent, the evaporating temperature t is taken as a feedback signal, the refrigerating output is reduced by unloading the adjustable slide valve of the compressor to control the evaporating temperature, and the evaporating temperature is controlled to be more than 1 ℃; when the compressor can adjust the slide valve to unload to reduce the output of the compressor to less than 50%, the adjustment of the compressor can be stopped, namely, the adjustment proportion psi is less than 50%, the valve position is kept unchanged, if the evaporation temperature t is still continuously reduced, the hot gas bypass electronic expansion valve is opened, the evaporation temperature t is taken as a feedback signal, the opening degree of the hot gas bypass electronic expansion valve is used for continuously adjusting the reduction of the refrigeration capacity of the compressor so as to control the evaporation temperature to be more than 1 ℃.
3. The chiller anti-freezing control method according to claim 2, wherein in the anti-freezing mode, the compressor regulating valve adopts a PWM (pulse width modulation) mode of PID (proportion integration differentiation) control to improve the response speed of control, and the hot gas bypass electronic expansion valve adopts PID control.
4. The chiller freezing prevention control method according to any one of claims 1, 2 or 3, wherein the control is based on the chiller refrigeration system suction pressure PaThe calculation formula for calculating the evaporation temperature t is as follows:
t＝a3Pa 3+a2Pa 2+a1Pa-a0，
in the formula a0～a3And fitting coefficients of a polynomial for the evaporation temperature t, and obtaining the coefficient by acquiring parameters of the evaporation temperature and the suction pressure of the water chilling unit and fitting the parameters by a linear regression method.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114992801A (en) * | 2022-05-10 | 2022-09-02 | 青岛海尔空调电子有限公司 | Air conditioning system and control method thereof |
| CN115823786A (en) * | 2022-12-08 | 2023-03-21 | 珠海格力电器股份有限公司 | Unit anti-freezing control method and device and water chilling unit |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4691526A (en) * | 1985-05-08 | 1987-09-08 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Air conditioning unit for vehicle |
| CN203190732U (en) * | 2013-03-27 | 2013-09-11 | 广东申菱空调设备有限公司 | Anti-freezing water chilling unit |
| CN104089347A (en) * | 2014-06-24 | 2014-10-08 | 广东申菱空调设备有限公司 | Low-temperature air-cooled water chiller unit and control method thereof |
| WO2015131184A1 (en) * | 2014-02-28 | 2015-09-03 | Abtahi Amir | Freeze inhibiting regrigeration circuit and method of operation |
| CN106482376A (en) * | 2016-09-10 | 2017-03-08 | 赵向辉 | Refrigeration or heat pump and its refrigerant circulation amount adjustment method |
| CN107576107A (en) * | 2017-07-18 | 2018-01-12 | 广东美的暖通设备有限公司 | A kind of method for preventing heat exchanger from freezing, system and air cooling module unit |
| CN111964318A (en) * | 2020-08-15 | 2020-11-20 | 王咏伦 | Capacity adjusting method of screw unit and system for realizing same |
-
2021
- 2021-10-20 CN CN202111229977.7A patent/CN113865167B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4691526A (en) * | 1985-05-08 | 1987-09-08 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Air conditioning unit for vehicle |
| CN203190732U (en) * | 2013-03-27 | 2013-09-11 | 广东申菱空调设备有限公司 | Anti-freezing water chilling unit |
| WO2015131184A1 (en) * | 2014-02-28 | 2015-09-03 | Abtahi Amir | Freeze inhibiting regrigeration circuit and method of operation |
| CN104089347A (en) * | 2014-06-24 | 2014-10-08 | 广东申菱空调设备有限公司 | Low-temperature air-cooled water chiller unit and control method thereof |
| CN106482376A (en) * | 2016-09-10 | 2017-03-08 | 赵向辉 | Refrigeration or heat pump and its refrigerant circulation amount adjustment method |
| CN107576107A (en) * | 2017-07-18 | 2018-01-12 | 广东美的暖通设备有限公司 | A kind of method for preventing heat exchanger from freezing, system and air cooling module unit |
| CN111964318A (en) * | 2020-08-15 | 2020-11-20 | 王咏伦 | Capacity adjusting method of screw unit and system for realizing same |
Non-Patent Citations (1)
| Title |
|---|
| 石文星: "《小型空调热泵装置设计》", 31 October 2013, 中国建筑工业出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114992801A (en) * | 2022-05-10 | 2022-09-02 | 青岛海尔空调电子有限公司 | Air conditioning system and control method thereof |
| CN114992801B (en) * | 2022-05-10 | 2024-03-22 | 青岛海尔空调电子有限公司 | Air conditioning system and control method thereof |
| CN115823786A (en) * | 2022-12-08 | 2023-03-21 | 珠海格力电器股份有限公司 | Unit anti-freezing control method and device and water chilling unit |
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| CN113865167B (en) | 2023-04-07 |
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