CN114279049A - Refrigerating unit and control method for automatically optimizing frequency of variable frequency fan of refrigerating unit - Google Patents
Refrigerating unit and control method for automatically optimizing frequency of variable frequency fan of refrigerating unit Download PDFInfo
- Publication number
- CN114279049A CN114279049A CN202111581411.0A CN202111581411A CN114279049A CN 114279049 A CN114279049 A CN 114279049A CN 202111581411 A CN202111581411 A CN 202111581411A CN 114279049 A CN114279049 A CN 114279049A
- Authority
- CN
- China
- Prior art keywords
- fan
- compressor
- frequency
- refrigerating unit
- stage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 31
- 238000011217 control strategy Methods 0.000 claims abstract description 18
- 238000005057 refrigeration Methods 0.000 claims description 14
- 238000005457 optimization Methods 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 230000006641 stabilisation Effects 0.000 claims 1
- 238000011105 stabilization Methods 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 22
- 238000005070 sampling Methods 0.000 description 9
- 230000007613 environmental effect Effects 0.000 description 7
- 238000001704 evaporation Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Abstract
The invention discloses a refrigerating unit and a control method for automatically optimizing the frequency of a variable-frequency fan of the refrigerating unit. The control method for automatically optimizing the frequency of the variable frequency fan of the refrigerating unit comprises the following steps: dividing the operation process of the refrigerating unit into different stages in advance, and making different control strategies for each stage; judging the stage of the current refrigerating unit; and controlling the frequency of the fan according to a corresponding control strategy. The operation process of the refrigerating unit is divided into a plurality of stages, and a corresponding control strategy is formulated for each stage, so that the control of the fan is more suitable for the current requirement, the hysteresis is reduced, and the control is convenient and practicable.
Description
Technical Field
The invention relates to the technical field of control of variable frequency fans, in particular to a refrigerating unit and a control method for automatically optimizing the frequency of a variable frequency fan of the refrigerating unit.
Background
The fan is one of the important parts of the refrigerating unit, and the frequency control of the variable frequency fan is always one direction for optimizing energy efficiency of manufacturers.
The prior art discloses a control method of a variable frequency fan of a water chilling unit and an air conditioner, wherein the energy efficiency ratio of the water chilling unit is calculated and compared by acquiring the water inlet temperature and the water outlet temperature of the water chilling unit and the current of the unit, and the rotating speed of the variable frequency fan is adjusted according to the comparison result of the energy efficiency ratio, so that the purpose of the optimal energy efficiency ratio of the water chilling unit is achieved. However, the water temperature has hysteresis, so that the operation state of the reaction unit cannot be better, the control hysteresis exists, and the whole scheme is complex to control and poor in operability.
The prior art discloses an evaporative cooling type water chilling unit, a control method and a control system thereof, wherein the frequency of a variable frequency fan and a variable frequency water pump is controlled according to the range of exhaust pressure and the wet bulb temperature difference value of inlet air and outlet air of a condenser by detecting the wet bulb temperature of inlet air and outlet air of the condenser and the exhaust pressure of a compressor, so that the problem of optimal unit energy efficiency ratio due to the control of air volume and water volume of the evaporative cooling type water chilling unit is mainly solved.
Disclosure of Invention
The invention provides a refrigerating unit and a control method for automatically optimizing the frequency of a variable frequency fan of the refrigerating unit, and aims to solve the technical problems that the control of the variable frequency fan of the refrigerating unit in the prior art has hysteresis and is relatively complex to control.
The invention provides a control method for automatically optimizing the frequency of a variable frequency fan of a refrigerating unit, which comprises the following steps:
dividing the operation process of the refrigerating unit into different stages in advance, and making different control strategies for each stage;
judging the stage of the current refrigerating unit;
and controlling the frequency of the fan according to a corresponding control strategy.
Further, the operation process of the refrigerating unit is divided into a fan starting stage, a compressor loading stage and a fan frequency optimizing stage.
Further, when the refrigeration unit is started and the compressor is not operated, the fan starting stage is determined when the stage of the current refrigeration unit is determined.
Further, when the compressor starts to operate until the stable operation time of the compressor is less than or equal to the set stable time, judging that the current stage of the refrigerating unit is the compressor loading stage.
Further, when the stable operation of the compressor is longer than the set stable time, the fan optimizing stage is judged when the stage of the current refrigerating unit is judged.
Further, in the starting stage of the fan, the control strategy is to control the frequency of the fan according to the environment temperature when the fan is started.
Further, in the loading stage of the compressor, the control strategy is to control the frequency of the fan according to the exhaust pressure of the compressor.
Further, in the fan optimizing stage, the control strategy is to control the frequency of the fan according to the exhaust pressure of the compressor and the current of the compressor.
Further, when a plurality of compressors are provided, if the compressors are connected in parallel, the exhaust pressure of the compressors is the exhaust pressure of the total exhaust pipe of all the compressors; if the compressors are connected in series, the exhaust pressure of the compressors is the average value of the exhaust pressures of all the compressors; the current of the compressor is the average value of the current of all the compressors.
The refrigerating unit provided by the invention comprises the fan and the controller, wherein the controller controls the fan frequency by adopting the control method for automatically optimizing the fan frequency of the refrigerating unit.
Further, the refrigerating unit comprises a variable frequency evaporation refrigerating unit.
The invention divides the operation process of the unit into a plurality of stages, and controls the frequency of the fan according to the characteristics of the fan in each stage, so that the frequency control of the fan is more suitable for the current requirement, the hysteresis is avoided, and the control mode is relatively simple and can be implemented. In the loading stage of the compressor and the optimizing stage of the fan, because the exhaust pressure of the compressor is used as the standard to control the frequency of the fan, the power consumption is further reduced on the premise that the refrigerating capacity of the refrigerating unit meets the requirements of users, and the energy efficiency of the unit is optimized.
Drawings
The invention is described in detail below with reference to examples and figures, in which:
fig. 1 is a timing diagram of the unit from power on to power off according to an embodiment of the present invention.
FIG. 2 is a control flow diagram of an embodiment of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Thus, a feature indicated in this specification will serve to explain one of the features of one embodiment of the invention, and does not imply that every embodiment of the invention must have the stated feature. Further, it should be noted that this specification describes many features. Although some features may be combined to show a possible system design, these features may also be used in other combinations not explicitly described. Thus, the combinations illustrated are not intended to be limiting unless otherwise specified.
The control method for automatically optimizing the frequency of the variable frequency fan of the refrigerating unit divides the operation process of the refrigerating unit into different stages in advance, and sets different control strategies for each stage. And when the unit runs, judging the stage of the current refrigerating unit, and controlling the frequency of the fan according to a corresponding control strategy.
As shown in fig. 1, taking the frequency conversion evaporation chiller unit as an example, a complete timing chart from start-up to shutdown of the frequency conversion evaporation chiller unit is shown in the figure, and the frequency conversion evaporation chiller unit is hereinafter referred to as the chiller unit for short.
When the unit receives a starting command, the unit enters self-checking. If the unit is abnormal and meets the starting condition, the fan and the water pump are started, the compressor is started after the starting condition of the compressor is met, and then automatic adjustment is carried out according to a preset program. When the unit receives a shutdown command, a compressor of the unit is closed first, and the fan and the water pump are closed after the compressor is closed.
The time Tcp marked in the figure is the time for the fan and the water pump to start the compressor in advance, wherein the starting time of the fan and the water pump can be the same or different, and a user can set the time according to the actual situation. If the time for opening the fan in advance of the compressor is set to be 60s, and the time for opening the water pump in advance of the compressor is set to be 60s, the fan and the water pump are simultaneously opened. A typical more conventional time setting is 60s for the water pump to advance the compressor on and 120s for the blower to advance the compressor on.
When the unit is provided with a plurality of compressors, the compressors are not started simultaneously but have time intervals, the compressors of the system are started firstly, the compressors of the system II are started again at intervals of 3-5 s, and the compressor is closed firstly according to the closing principle.
The time Tcy is the time for delaying the closing of the compressor by the fan and the water pump, and can be the same or different. The customer can set up according to actual conditions, if set up the time that fan time delay compressor was closed to 60s, the time that water pump time delay compressor was closed sets up to 60s, then fan and water pump were closed simultaneously. The more conventional time setting is that the time for delaying the closing of the compressor by the water pump is 60s, and the time for delaying the closing of the compressor by the fan is 120 s.
In one embodiment, the present invention divides the operation of a refrigeration unit into a fan start-up phase, a compressor loading phase, and a fan frequency optimization phase based on the above process, as shown in figure 2. And when the refrigerating unit is started and the compressor does not run, judging that the current stage of the refrigerating unit is a fan starting stage. And when the compressor starts to operate until the stable operation time of the compressor is less than or equal to the set stable time, judging that the current stage of the refrigerating unit is the stage of loading the compressor. And when the stable operation of the compressor is longer than the set stable time, namely the stable operation time t of the compressor is longer than the set stable time delta t, judging that the fan optimizing stage is the stage where the current refrigerating unit is located.
In the specific implementation process, after the compressor is started, the fan starting stage is started, whether the compressor loading stage is started or not is judged according to the state of the compressor, and if the compressor is detected to run, namely the state of the compressor is started, the compressor loading stage is started. If the compressor running is not detected, namely the state of the compressor is off, the loading stage of the compressor is not entered.
And after entering the loading stage of the compressor, judging whether to enter a fan optimizing stage according to the stable running time of the compressor and the set stable time, and if the stable running time of the compressor is detected to be greater than the set stable time, entering the fan optimizing stage. And if the stable running time of the compressor is detected to be less than or equal to the set stable time, the fan optimizing stage is not started.
In general, when the stable operation time of the compressor exceeds 30min, the unit refrigeration is considered to be stably operated, that is, the output refrigeration amount is a fixed value, so the set stable time is usually 30 min.
In the starting stage of the fan, the control strategy is to control the frequency of the fan according to the environmental temperature when the fan is started. The ambient temperature may be divided into a plurality of temperature intervals and then the frequency of the fan may be controlled according to the different temperature intervals. If the ambient temperature is greater than T1, the fan frequency is F1; the environmental temperature is more than T2 and less than or equal to T1, and the fan frequency is F2; the environmental temperature is less than or equal to T2, and the fan frequency is F3.
In specific implementation, the frequency of the fan may be a fixed value or a percentage of the rated frequency.
In one embodiment, if the ambient temperature is greater than 15 ℃, the fan frequency is 25 Hz; if the environmental temperature is higher than 5 ℃ and lower than or equal to 15 ℃, the frequency of the fan is 20 Hz; if the environmental temperature is less than or equal to 5 ℃, the fan frequency is 0.
In another embodiment, if the ambient temperature is > 15 ℃, the fan frequency is 100% a; if the environmental temperature is higher than 5 ℃ and lower than or equal to 15 ℃, the fan frequency is 50 percent A; if the environmental temperature is less than or equal to 5 ℃, the fan frequency is 0. Wherein A is the rated frequency of the fan.
In the loading stage of the compressor, the control strategy is to control the frequency of the fan according to the exhaust pressure of the compressor. The discharge pressure of the compressor is judged by setting a target high-pressure and a corresponding deviation value. When the exhaust pressure P is larger than or equal to the target high pressure P0+ positive deviation delta P, increasing the fan frequency; when the target high-pressure P0-positive deviation delta P is smaller than the exhaust pressure P and smaller than the target high-pressure P0+ positive deviation delta P, the fan frequency is unchanged; and when the exhaust pressure P is less than or equal to the target high pressure P0-positive deviation delta P, reducing the frequency of the fan.
In one embodiment, if the discharge pressure P-target high pressure P0 is greater than or equal to 50, the fan frequency is increased; if the exhaust pressure is more than 50 below zero and the target high pressure P0 is less than 50 below zero, the frequency of the fan is unchanged; and if the exhaust pressure P-target high pressure P0 is less than or equal to 50, reducing the frequency of the fan.
In the fan optimizing stage, the control strategy is to control the frequency of the fan according to the exhaust pressure of the compressor and the current of the compressor.
For example, taking a sampling period of 60 seconds as an example, when a difference value between a discharge pressure of a compressor in a current sampling period and a discharge pressure of a previous sampling period is less than or equal to a preset interpolation value, and a difference value between a current of the compressor in the current sampling period and a current of the compressor in the previous sampling period is less than or equal to a preset difference value, the frequency of the fan is reduced. Expressed by formula, | P-Pt-60| ≦ Δ P and | I-It-60| is less than Δ I, the frequency of the fan is reduced. Wherein P is the discharge pressure of the compressor in the current sampling period, Pt-60The discharge pressure of the compressor of the last sampling period, I is the current of the compressor of the current sampling period, It-60The current of the compressor of the last sampling period.
In the above technical solution, if there is more than one compressor of the unit, that is, there are multiple compressors, if the compressors are connected in parallel, the discharge pressure of the above compressor is the discharge pressure of the total discharge pipe of all the compressors. If a plurality of compressors are connected in series, the discharge pressure of the compressor is the average of the discharge pressures of all the compressors. The current of the compressor is the average value of the current of all the compressors.
The invention reduces the frequency of the fan under the condition of certain refrigerating capacity of the unit, can ensure the refrigerating capacity requirement of a user and simultaneously reduces the energy consumption.
The invention also protects the refrigerating unit, the refrigerating unit comprises a fan and a controller, and the controller adopts the control method for automatically optimizing the fan frequency of the refrigerating unit to control the fan frequency. The refrigeration unit referred to in the present invention includes, but is not limited to, a variable frequency evaporation refrigeration unit.
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.
Claims (11)
1. A control method for automatically optimizing the frequency of a variable frequency fan of a refrigerating unit is characterized by comprising the following steps:
dividing the operation process of the refrigerating unit into different stages in advance, and making different control strategies for each stage;
judging the stage of the current refrigerating unit;
and controlling the frequency of the fan according to a corresponding control strategy.
2. The method as set forth in claim 1, wherein the operation of said refrigeration unit is divided into a fan start-up phase, a compressor loading phase and a fan frequency optimization phase.
3. The method as set forth in claim 2, wherein when said refrigeration unit is started and said compressor is not running, it is determined that the fan is in a starting phase when the current phase of the refrigeration unit is determined.
4. The method as set forth in claim 2, wherein when said compressor starts to operate until the stable operation time of the compressor is less than or equal to the set stable time, the compressor loading stage is determined when the current stage of the refrigeration unit is determined.
5. The method as set forth in claim 2, wherein when said compressor is stably operated for more than a predetermined stabilization time, it is determined that the current stage of the refrigerating unit is the fan optimizing stage.
6. The method as set forth in claim 2, wherein said control strategy is to control the fan frequency according to the ambient temperature at the fan start-up time during the fan start-up phase.
7. The method as set forth in claim 2, wherein said control strategy is to control the frequency of the fan based on the discharge pressure of said compressor during the compressor loading phase.
8. The method as set forth in claim 2, wherein said control strategy is to control the fan frequency according to the discharge pressure of the compressor and the current of the compressor during the fan optimization phase.
9. The control method for automatically optimizing the frequency of the variable frequency fan of the refrigerating unit as set forth in claim 7 or 8, wherein when there are a plurality of compressors, if the compressors are connected in parallel, the discharge pressure of the compressor is the discharge pressure of the total discharge pipe of all the compressors; if the compressors are connected in series, the exhaust pressure of the compressors is the average value of the exhaust pressures of all the compressors; the current of the compressor is the average value of the current of all the compressors.
10. A refrigeration unit comprising a fan and a controller for controlling the fan frequency using the method of automatic fan frequency optimization according to any one of claims 1 to 9.
11. The refrigeration unit as set forth in claim 10 wherein said refrigeration unit comprises a variable frequency evaporative cooling unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111581411.0A CN114279049A (en) | 2021-12-22 | 2021-12-22 | Refrigerating unit and control method for automatically optimizing frequency of variable frequency fan of refrigerating unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111581411.0A CN114279049A (en) | 2021-12-22 | 2021-12-22 | Refrigerating unit and control method for automatically optimizing frequency of variable frequency fan of refrigerating unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114279049A true CN114279049A (en) | 2022-04-05 |
Family
ID=80873842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111581411.0A Pending CN114279049A (en) | 2021-12-22 | 2021-12-22 | Refrigerating unit and control method for automatically optimizing frequency of variable frequency fan of refrigerating unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114279049A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140096547A1 (en) * | 2012-10-10 | 2014-04-10 | Trane International Inc. | Variable fan speed control in hvac systems and methods |
| TW201736790A (en) * | 2016-02-10 | 2017-10-16 | 江森自控科技公司 | Systems and methods for controlling a refrigeration system |
| CN108006919A (en) * | 2017-11-15 | 2018-05-08 | 珠海格力电器股份有限公司 | A kind of evaporation cooling type cold water unit, its control method and control system |
| CN110736275A (en) * | 2019-11-14 | 2020-01-31 | 无锡职业技术学院 | variable frequency fan speed regulation control method for optimizing efficiency of refrigeration system |
| CN112361682A (en) * | 2020-10-15 | 2021-02-12 | 珠海格力电器股份有限公司 | Water chilling unit control method and device and water chilling unit |
| CN112393482A (en) * | 2020-11-20 | 2021-02-23 | 珠海格力电器股份有限公司 | Variable-frequency air-cooled water chilling unit and variable-working-condition starting control method thereof |
| CN112577169A (en) * | 2021-02-26 | 2021-03-30 | 山东雅士股份有限公司 | Control method for frequency conversion unit type air conditioning |
| CN112594884A (en) * | 2020-12-10 | 2021-04-02 | 珠海格力电器股份有限公司 | Air conditioning unit and condenser fan control method and device thereof and storage medium |
| CN113639396A (en) * | 2021-08-23 | 2021-11-12 | 青岛海尔空调电子有限公司 | Control method for air conditioning system |
-
2021
- 2021-12-22 CN CN202111581411.0A patent/CN114279049A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140096547A1 (en) * | 2012-10-10 | 2014-04-10 | Trane International Inc. | Variable fan speed control in hvac systems and methods |
| TW201736790A (en) * | 2016-02-10 | 2017-10-16 | 江森自控科技公司 | Systems and methods for controlling a refrigeration system |
| CN108006919A (en) * | 2017-11-15 | 2018-05-08 | 珠海格力电器股份有限公司 | A kind of evaporation cooling type cold water unit, its control method and control system |
| CN110736275A (en) * | 2019-11-14 | 2020-01-31 | 无锡职业技术学院 | variable frequency fan speed regulation control method for optimizing efficiency of refrigeration system |
| CN112361682A (en) * | 2020-10-15 | 2021-02-12 | 珠海格力电器股份有限公司 | Water chilling unit control method and device and water chilling unit |
| CN112393482A (en) * | 2020-11-20 | 2021-02-23 | 珠海格力电器股份有限公司 | Variable-frequency air-cooled water chilling unit and variable-working-condition starting control method thereof |
| CN112594884A (en) * | 2020-12-10 | 2021-04-02 | 珠海格力电器股份有限公司 | Air conditioning unit and condenser fan control method and device thereof and storage medium |
| CN112577169A (en) * | 2021-02-26 | 2021-03-30 | 山东雅士股份有限公司 | Control method for frequency conversion unit type air conditioning |
| CN113639396A (en) * | 2021-08-23 | 2021-11-12 | 青岛海尔空调电子有限公司 | Control method for air conditioning system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110579046A (en) | Control method and device for electronic expansion valve in multi-split refrigeration operation | |
| CN109028491B (en) | Variable frequency air conditioner compressor soft start method and system and air conditioner | |
| CN111023458B (en) | Electronic expansion valve control method for prolonging frosting period and air conditioner | |
| CN109751911B (en) | Self-adaptive adjusting method for fan frequency of cooling tower and air conditioning system | |
| CN110260492B (en) | Fan and compressor control method under refrigeration mode of variable frequency air conditioner | |
| CN110953778B (en) | Control method and system of refrigeration equipment, refrigeration equipment and readable storage medium | |
| CN112393482B (en) | Variable-frequency air-cooled water chilling unit and variable-working-condition starting control method thereof | |
| CN114811860B (en) | Control method of multi-split air conditioning system and multi-split air conditioning system | |
| CN111397167B (en) | Double-frequency conversion system, control method of frequency conversion compressor of double-frequency conversion system and storage medium | |
| CN112710069A (en) | Refrigeration control method and device of air conditioner and air conditioner | |
| CN114294789B (en) | Control method of air conditioning system, air conditioning system and air conditioner | |
| CN113531783B (en) | Refrigeration anti-freezing control method and device of multi-connected air conditioning system | |
| CN114034155A (en) | Method for calculating ring temperature and controlling rotating speed of compressor | |
| CN114183885A (en) | Multi-connected air conditioning unit and control method thereof | |
| CN111306732B (en) | Control method of drainage water pump of water receiving disc of air conditioner and air conditioner | |
| CN114279049A (en) | Refrigerating unit and control method for automatically optimizing frequency of variable frequency fan of refrigerating unit | |
| CN113405289B (en) | Heat pump exhaust temperature adjusting method | |
| CN114198859A (en) | Compressor oil return control method and air conditioner | |
| CN110701841B (en) | Control method of variable-frequency air source heat pump | |
| CN113587339A (en) | Control method and device for rapidly balancing pressure difference of air conditioning system and air conditioner | |
| CN113834246A (en) | Control method and device of bypass valve, controller and refrigeration equipment | |
| CN114508808B (en) | Magnetic suspension variable frequency water chilling unit | |
| CN117450623B (en) | Compressor frequency control method and air conditioning unit | |
| US11879468B2 (en) | Control method for centrifugal compressor and air conditioning system | |
| CN115978885A (en) | Control method of variable frequency fan of refrigerator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20220411 Address after: 519070 9 Building (Science and technology building) 789 Jinji Road, Qianshan, Zhuhai, Guangdong Applicant after: GREE GREEN REFRIGERATION TECHNOLOGY CENTER Co.,Ltd. OF ZHUHAI Address before: 519000 Qianshan Golden Chicken West Road in Zhuhai, Guangdong Applicant before: GREE ELECTRIC APPLIANCES Inc. OF ZHUHAI |
|
| TA01 | Transfer of patent application right | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220405 |