CN103925755A - Operation control method for condensation side fan unit of refrigerating system - Google Patents
Operation control method for condensation side fan unit of refrigerating system Download PDFInfo
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- CN103925755A CN103925755A CN201310021318.3A CN201310021318A CN103925755A CN 103925755 A CN103925755 A CN 103925755A CN 201310021318 A CN201310021318 A CN 201310021318A CN 103925755 A CN103925755 A CN 103925755A
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- frequency
- frequency conversion
- condensation side
- refrigeration system
- blower fan
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- 238000000034 method Methods 0.000 title claims abstract description 23
- 230000005494 condensation Effects 0.000 title claims description 41
- 238000009833 condensation Methods 0.000 title claims description 41
- 238000005057 refrigeration Methods 0.000 claims abstract description 34
- 238000006243 chemical reaction Methods 0.000 claims description 54
- 230000001276 controlling effect Effects 0.000 abstract description 5
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 230000001052 transient effect Effects 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 6
- 238000001816 cooling Methods 0.000 description 4
- 238000003556 assay Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 1
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Abstract
The invention discloses a method for controlling the operation of a condensing side fan unit of a refrigerating system, wherein the condensing side fan unit of the refrigerating system comprises a variable frequency fan and at least one fixed frequency fan, and the control method monitors the high pressure P of the systemHeight ofAnd is judged with a preset first reference value P1 and a second reference value P2 according to the high pressure PHeight ofIn the section, whether the high pressure P is needed or not is judgedHeight ofAdjusting when the high pressure P is judged to be requiredHeight ofWhen adjusting, the operation of the variable frequency fan is adjusted at a preset speedFrequency, effecting a high pressure PHeight ofIs regulated smoothly, avoids high pressure PHeight ofThe system is unstable due to large transient variation, thereby improving the stability of the operation of the refrigeration system.
Description
Technical field
The present invention relates to control field, specially refer to refrigeration system condensation side blower fan group method for controlling of operation.
Background technology
Refrigeration system, at the blower fan of condensation side, is taked adjustable gear blower fan more at present, by regulating the gear of blower fan to control the start and stop of blower fan, ruuning situation.So just there is unit at low temperature environment (≤-5 ℃) even if blower fan is with the increase rotation speed of fan of transferring the files in the startup of lowest gear rotating speed or operation process down, also can cause the variation of refrigeration system high pressure pressure moment larger, and low pressure in refrigeration system is normally more stable, thereby can cause the difference of refrigeration system high pressure pressure and low pressure to have larger variation in moment.
The helical-lobe compressor for example using for air-cooled screw unit; the difference that at least will guarantee high-pressure and low pressure is more than 4bar; guarantee unit is to normal oil return in compressor; when the difference of high-pressure and low pressure is guarded against pressure lower than this; likely cause for shortage of oil; burn compressor, affect the reliability of unit.And the variation of blower fan gear can cause high-pressure to reduce suddenly, in the process reducing, likely cause the difference of high-pressure and low pressure to level off to 4bar, cause the fluctuation of machine system large especially, affect complete machine security, reliability.
Summary of the invention
The refrigeration system high pressure pressure that problem to be solved by this invention causes while being condensation side blower fan to transfer the files has a larger fluctuation instantaneous, provide a kind of condensation side blower fan group to comprise the control method of the refrigeration system of frequency conversion fan, can realize the steady adjusting of system high pressure pressure, improve the stability of refrigeration system.
Refrigeration system condensation side blower fan group method for controlling of operation provided by the invention, refrigeration system condensation side blower fan group comprises a frequency conversion fan and at least one fixed blower fan frequently, this control method comprises the following steps:
Step 1: detect refrigeration system high pressure pressure P
high, high-pressure P is high, and with first reference value P1, the second a reference value P2 compares, wherein P1 > P2; If P
high> P1, performs step two, if P2 < is P
high< P1, keeps current condensation side blower fan group ruuning situation constant, if P
high< P2, reduces the running frequency of frequency conversion fan with set rate k1; Step 2: judge that frequency conversion fan, whether by highest frequency running, if frequency conversion fan is not with highest frequency running, improves the running frequency of frequency conversion fan with set rate k2, if frequency conversion fan has been pressed highest frequency running, open a fixed blower fan frequently more.
Further, after refrigeration system starts, carry out following steps:
S1: detect refrigeration system high pressure pressure P
high;
S2: by high-pressure P
high, P1 compares with first reference value, if P
high>=P1, starts described frequency conversion fan with predeterminated frequency, if P
high< P1, does not open blower fan.So, can improve unit startup stage, realize high-pressure P
highbalance adjustment, can there is not moment larger fluctuation.
Adopt refrigeration system condensation side blower fan group method for controlling of operation provided by the invention, owing to having monitored the high-pressure P of system
high, and judge with default first reference value and the second a reference value, according to high-pressure interval of living in, judgement is worked as need to be to high-pressure P
highwhile regulating, first, by regulate the running frequency of frequency conversion fan with set rate, realize high-pressure P
highsteady adjusting, avoided high-pressure P
highin moment, there is larger change, cause system unstable, improved thus the stability of refrigeration system operation.
Accompanying drawing explanation
Fig. 1 is the control flow chart of embodiments of the invention one
The specific embodiment
Below with reference to accompanying drawing, also the present invention is described in detail in conjunction with the embodiments.It should be noted that, in the situation that not conflicting, the feature in following embodiment and embodiment can combine mutually.
Embodiment mono-
In first embodiment of the invention, take Worm type air-cooled handpiece Water Chilling Units as example, the condensation side of this unit adopts air cooling heat exchanger, and condensation side blower fan group adopts 1 frequency conversion fan and 3 fixed blower fans frequently altogether.
Set the high-pressure P of this unit
highjudgment standard value, first reference value P1 is 14bar, the second a reference value P2 is 9bar, system high pressure protection pressure P
protectfor 26bar; Set the high-pressure P of this unit
highassay intervals time t
0for 10s, applicant finds, improves the air quantity of condensation side blower fan group, can reduce refrigeration system high pressure pressure P
high, the air quantity of reduction condensation side blower fan group, high-pressure P can raise
high.In the first embodiment, as follows to the concrete control method of carrying out of condensation side blower fan group:
S1, unit start;
S2, detection high-pressure P
highif, P
high> 14bar, opens frequency conversion fan with the minimum startup frequency of frequency conversion fan, if P
high≤ 14bar, keeps the current fan operation situation of unit constant, does not open blower fan;
S3, detection high-pressure P
highif, P
high> 14bar, carries out S4, if 9bar < is P
high< 14bar, keeps the current fan operation situation of unit constant, if P
high< 9bar, reduces the frequency of frequency conversion fan, until frequency conversion fan is shut down with set rate k1;
If S4 frequency conversion fan not full gear turns round, with set rate k2, promote the frequency of frequency conversion fan, until the operation of frequency conversion fan full gear, if full gear running of frequency conversion fan continues fixed blower fan frequently of unlatching, until all blower fans are all opened.
At interval of 10s, carry out one time S3.
Wherein, set rate k1 and k2 are 2% of adjusting frequency conversion fan rated frequency A per second, i.e. k1=k2=2%*A/s.Can certainly, according to the requirement of degree of regulation, suitably improve or reduce set rate k1 or k2.
A high-pressure P in office
highdetection in, if P
high>=26bar, judges that system pressure is too high, carries out and shuts down at once, carries out system protection.
Certainly, the quantity of determining frequency blower fan in the present embodiment also can be adjusted into other quantity according to air cooling heat exchanger capacity, is preferably odd number, such as being also 5 or 7 etc.
Embodiment bis-
In second embodiment of the invention, take Worm type air-cooled handpiece Water Chilling Units as example, the condensation side of this unit adopts air cooling heat exchanger, and condensation side blower fan group adopts 1 frequency conversion fan and 3 fixed blower fans frequently altogether.
Set the high-pressure P of this unit
highjudgment standard value, first reference value P1 is 9bar, the second a reference value P2 is 14bar, system high pressure protection pressure P
protectfor 26bar; Set the high-pressure P of this unit
highassay intervals time t
0for 10s, as follows to the concrete control method of carrying out of condensation side blower fan group:
S1, unit start;
S2, detection high-pressure P
highif, P
high> 14bar, detects the environment temperature T of condensation side, according to the environment temperature T of condensation side interval of living in, determines the startup frequency A of frequency conversion fan
0and start this frequency conversion fan; If P
high≤ 14bar, keeps the current fan operation situation of unit constant, does not open blower fan;
S3, detection high-pressure P
highif, P
high> 14bar, carries out S4, if 9bar < is P
high< 14bar, keeps the current fan operation situation of unit constant, if P
high< 9bar, reduces the frequency of frequency conversion fan, until frequency conversion fan is shut down with set rate k1;
If S4 frequency conversion fan not full gear turns round, with set rate k2, promote the frequency of frequency conversion fan, until the operation of frequency conversion fan full gear, if full gear running of frequency conversion fan continues fixed blower fan frequently of unlatching, until blower fan is all opened.
At interval of 10s, carry out one time S3.
Wherein, set rate k1 is 2% of adjusting frequency conversion fan rated frequency A per second, i.e. k1=2%*A/s.And set rate k2 is 3% of adjusting frequency conversion fan rated frequency A per second, i.e. k2=3%*A/s.Can certainly, according to the requirement of degree of regulation, suitably improve or reduce set rate k1 or k2.
A high-pressure P in office
highdetection in, if P
high>=26bar, judges that system pressure is too high, carries out and shuts down at once, carries out system protection.
In S2 step, the startup frequency A of the environment temperature T of condensation side interval of living in and frequency conversion fan
0relation can be according to the environmental quality of different regions, be set in advance in the controller of unit, for example, for the larger area of range of temperature, the environment temperature T of condensation side can be decomposed into 5 temperature ranges, the different proportion of corresponding frequency conversion fan rated frequency A respectively, the interval corresponding frequency of different temperatures, minimum can not be lower than the minimum startup frequency of frequency conversion fan, for example minimum startup frequency is rated frequency 10% time, shown in concrete following table:
For the less area of range of temperature, the environment temperature T of condensation side can be decomposed into 3 temperature ranges, corresponding to the different proportion of frequency conversion fan rated frequency.
According to the environment temperature T of condensation side temperature of living in, determine the startup frequency of frequency conversion fan, can make frequency conversion fan more early must enter in rational range of operation, make unit enter sooner the state of stable operation.
Certainly, the quantity of determining frequency blower fan in the present embodiment also can be adjusted into other quantity according to air cooling heat exchanger capacity, is preferably odd number, such as being also 5 or 7 etc.
The above embodiment has only expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.
Claims (10)
1. refrigeration system condensation side blower fan group method for controlling of operation, described refrigeration system condensation side blower fan group comprises a frequency conversion fan and at least one fixed blower fan frequently, it is characterized in that, comprises the following steps:
Step 1: detect refrigeration system high pressure pressure P
high, by high-pressure P
highcompare with first reference value P1 and the second a reference value P2, wherein P1 > P2; If P
high> P1, performs step two, if P2 < is P
high< P1, keeps current condensation side blower fan group ruuning situation constant, if P
high< P2, reduces the running frequency of frequency conversion fan with set rate k1;
Step 2: judge whether frequency conversion fan turns round by highest frequency, if frequency conversion fan does not turn round with highest frequency, with set rate k2, improve the running frequency of described frequency conversion fan, if frequency conversion fan has been pressed highest frequency running, open a described fixed blower fan frequently more.
2. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 1, is characterized in that, after refrigeration system starts, carries out following steps:
Detect refrigeration system high pressure pressure P
high, by high-pressure P
high, P1 compares with first reference value, if P
high>=P1, starts described frequency conversion fan with predeterminated frequency, if P
high< P1, does not open blower fan.
3. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 2, is characterized in that the minimum startup frequency that described predeterminated frequency is frequency conversion fan.
4. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 1, is characterized in that, presets the environment temperature T of condensation side and the startup frequency A of frequency conversion fan
0relation, after refrigeration system start, carry out following steps:
Detect refrigeration system high pressure pressure P
high, by high-pressure P
highp1 compares with first reference value, if P
high>=P1, continuation detects the environment temperature T of condensation side, determines the startup frequency A of described frequency conversion fan according to the environment temperature T of condensation side
0, and start described frequency conversion fan, if P
high< P1, does not open blower fan.
5. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 4, is characterized in that, the environment temperature T of described condensation side is divided into some intervals, each interval startup frequency A of corresponding different frequency conversion fans respectively
0.
6. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 5, is characterized in that, the environment temperature T of described condensation side, the startup frequency A of frequency conversion fan
0and the rated frequency A of frequency conversion fan meets following relation:
When 15 ℃ of T >, A
0=100%A
When 5 ℃ of < T≤15 ℃, A
0=80%A
When-5 ℃ of < T≤5 ℃, A
0=50%A
When-15 ℃ of < T≤-5 ℃, A
0=30%A
When T≤-15 ℃, A
0=10%A.
7. the refrigeration system condensation side blower fan group method for controlling of operation as described in claim 4 or 5, is characterized in that described startup frequency A
0be not less than the minimum startup frequency of frequency conversion fan.
8. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 1 or 2, is characterized in that, described set rate k1 and k2 are 1%～3% of adjusting frequency conversion fan rated frequency A per second.
9. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 1 or 2, it is characterized in that, described set rate k1 is 2% of adjusting frequency conversion fan rated frequency A per second, and described set rate k2 is 3% of adjusting frequency conversion fan rated frequency A per second.
10. refrigeration system condensation side blower fan group method for controlling of operation as claimed in claim 1, is characterized in that, at interval of time t
0, carry out one time step 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310021318.3A CN103925755B (en) | 2013-01-16 | 2013-01-16 | Operation control method for condensation side fan unit of refrigerating system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310021318.3A CN103925755B (en) | 2013-01-16 | 2013-01-16 | Operation control method for condensation side fan unit of refrigerating system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103925755A true CN103925755A (en) | 2014-07-16 |
| CN103925755B CN103925755B (en) | 2016-06-08 |
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ID=51144055
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|---|---|---|---|
| CN201310021318.3A Active CN103925755B (en) | 2013-01-16 | 2013-01-16 | Operation control method for condensation side fan unit of refrigerating system |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104180573A (en) * | 2014-08-19 | 2014-12-03 | 重庆耐德能源装备集成有限公司 | Cooling system |
| CN104596054A (en) * | 2014-12-26 | 2015-05-06 | 珠海格力电器股份有限公司 | air conditioning unit fan control method and device |
| CN104764140A (en) * | 2015-03-19 | 2015-07-08 | 珠海格力电器股份有限公司 | Condensing pressure control method for refrigerating air conditioning unit |
| CN107178880A (en) * | 2017-07-03 | 2017-09-19 | 珠海格力电器股份有限公司 | method and device for controlling air conditioner |
| CN108006919A (en) * | 2017-11-15 | 2018-05-08 | 珠海格力电器股份有限公司 | Evaporative cooling type water chilling unit, and control method and control system thereof |
| CN111750481A (en) * | 2019-03-27 | 2020-10-09 | 日立江森自控空调有限公司 | Air conditioner control method and air conditioner 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 |
| US10941955B2 (en) | 2017-10-27 | 2021-03-09 | Dometic Sweden Ab | Systems, methods, and apparatuses for providing communications between climate control devices in a recreational vehicle |
| US11254183B2 (en) | 2017-08-25 | 2022-02-22 | Dometic Sweden Ab | Recreational vehicle, cooling device, controlling system and method for controlling the cooling device |
| CN115628530A (en) * | 2022-10-26 | 2023-01-20 | 珠海格力电器股份有限公司 | Fan control method, device and unit |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07198214A (en) * | 1993-12-28 | 1995-08-01 | Sanyo Electric Co Ltd | Speed regulator for condenser fan |
| US20060130501A1 (en) * | 2004-10-28 | 2006-06-22 | Abtar Singh | Variable speed condenser fan control system |
| US20080115515A1 (en) * | 2006-11-22 | 2008-05-22 | Bailey Peter F | Cooling system and method |
| CN201526483U (en) * | 2009-10-22 | 2010-07-14 | 同济大学 | Variable speed control system for condensate fan |
| KR100989026B1 (en) * | 2010-05-25 | 2010-10-20 | 주식회사 에이알 | Energy-saving thermo-hygrostat with functin of proportional control of condenser fan corresponding to refrigerant pressure and its control method thereof |
| CN102348945A (en) * | 2009-03-31 | 2012-02-08 | 江森自控科技公司 | Control system for operating condenser fans |
| JP2012072920A (en) * | 2010-09-27 | 2012-04-12 | Hitachi Appliances Inc | Refrigeration apparatus |
| CN102466304A (en) * | 2010-11-16 | 2012-05-23 | 力博特公司 | Air-conditioning system and control method of condensation fan thereof |
| CN102628630A (en) * | 2012-03-15 | 2012-08-08 | 青岛海尔空调电子有限公司 | Control method of air-cooling water chiller unit |
| CN202630496U (en) * | 2012-06-04 | 2012-12-26 | 广州日立冷机有限公司 | Air-cooled screw type water chiller unit |
-
2013
- 2013-01-16 CN CN201310021318.3A patent/CN103925755B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07198214A (en) * | 1993-12-28 | 1995-08-01 | Sanyo Electric Co Ltd | Speed regulator for condenser fan |
| US20060130501A1 (en) * | 2004-10-28 | 2006-06-22 | Abtar Singh | Variable speed condenser fan control system |
| US20080115515A1 (en) * | 2006-11-22 | 2008-05-22 | Bailey Peter F | Cooling system and method |
| CN102348945A (en) * | 2009-03-31 | 2012-02-08 | 江森自控科技公司 | Control system for operating condenser fans |
| CN201526483U (en) * | 2009-10-22 | 2010-07-14 | 同济大学 | Variable speed control system for condensate fan |
| KR100989026B1 (en) * | 2010-05-25 | 2010-10-20 | 주식회사 에이알 | Energy-saving thermo-hygrostat with functin of proportional control of condenser fan corresponding to refrigerant pressure and its control method thereof |
| JP2012072920A (en) * | 2010-09-27 | 2012-04-12 | Hitachi Appliances Inc | Refrigeration apparatus |
| CN102466304A (en) * | 2010-11-16 | 2012-05-23 | 力博特公司 | Air-conditioning system and control method of condensation fan thereof |
| CN102628630A (en) * | 2012-03-15 | 2012-08-08 | 青岛海尔空调电子有限公司 | Control method of air-cooling water chiller unit |
| CN202630496U (en) * | 2012-06-04 | 2012-12-26 | 广州日立冷机有限公司 | Air-cooled screw type water chiller unit |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104180573A (en) * | 2014-08-19 | 2014-12-03 | 重庆耐德能源装备集成有限公司 | Cooling system |
| CN104596054A (en) * | 2014-12-26 | 2015-05-06 | 珠海格力电器股份有限公司 | air conditioning unit fan control method and device |
| CN104764140A (en) * | 2015-03-19 | 2015-07-08 | 珠海格力电器股份有限公司 | Condensing pressure control method for refrigerating air conditioning unit |
| CN104764140B (en) * | 2015-03-19 | 2018-01-09 | 珠海格力电器股份有限公司 | Condensing pressure control method for refrigerating air conditioning unit |
| CN107178880A (en) * | 2017-07-03 | 2017-09-19 | 珠海格力电器股份有限公司 | method and device for controlling air conditioner |
| US11254183B2 (en) | 2017-08-25 | 2022-02-22 | Dometic Sweden Ab | Recreational vehicle, cooling device, controlling system and method for controlling the cooling device |
| US11919363B2 (en) | 2017-08-25 | 2024-03-05 | Dometic Sweden Ab | Recreational vehicle, cooling device, controlling system and method for controlling the cooling device |
| US10941955B2 (en) | 2017-10-27 | 2021-03-09 | Dometic Sweden Ab | Systems, methods, and apparatuses for providing communications between climate control devices in a recreational vehicle |
| CN108006919A (en) * | 2017-11-15 | 2018-05-08 | 珠海格力电器股份有限公司 | Evaporative cooling type water chilling unit, and control method and control system thereof |
| CN111750481A (en) * | 2019-03-27 | 2020-10-09 | 日立江森自控空调有限公司 | Air conditioner control method and air conditioner 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 |
| CN115628530A (en) * | 2022-10-26 | 2023-01-20 | 珠海格力电器股份有限公司 | Fan control method, device and unit |
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