CN101556068A - Constant pressure frequency conversion energy-saving control method of recycle pump in central air-conditioning system - Google Patents
Constant pressure frequency conversion energy-saving control method of recycle pump in central air-conditioning system Download PDFInfo
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- CN101556068A CN101556068A CNA2008100359432A CN200810035943A CN101556068A CN 101556068 A CN101556068 A CN 101556068A CN A2008100359432 A CNA2008100359432 A CN A2008100359432A CN 200810035943 A CN200810035943 A CN 200810035943A CN 101556068 A CN101556068 A CN 101556068A
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Abstract
The invention relates to a constant pressure frequency conversion energy-saving control method of a recycle pump in a central air-conditioning system, which is realized by the following steps: the pressure value of a pipe network is set to be H0, the initial water consumption of the pipe network to be QA, the initial working condition to be A, the rotation speed of the motor of the pump to be n1, and the shaft power of a working point A which is just the area surrounded by four points of AH0OQA is set; when the load of the pipe network is reduced, the pressure of the pipe network is increased, the pipe network outputs a signal enabling the frequency of a frequency transformator to lower, the rotation speed of the motor is lowered to n2 and moves from a point A to a point B; because the pressure value in a constant pressure water supply system is constant to be H0, the working point of the pump moves from the point A to the point B along the performance curve of the pump, which corresponds to the rotation speed n2, wherein the output pressure of the pump is raised at the stage, the flow is reduced and the pump runs at a new working point C; and the pump lift HC, the flow QC and the efficiency Eta C of the point C and the shaft power of the working point C which is the area surrounded by the four points of CH0OQC. The invention has the advantages of quite obvious power-saving effect and very considerable economical benefit.
Description
Technical field
The present invention relates to a kind of central air conditioner system, relate in particular to the control method of circulating pump in a kind of central air conditioner system.
Background technology
The design discharge of refrigerating water pump, coolant pump and circulating pump is that the surplus that adds about 10% by bad working environments down-off (being maximum stream flow) is selected in the central air conditioner system, and promptly water pump system moves with the maximum flow of water amount for a long time.Because the difference of season, variations in temperature round the clock and user's thermic load, the load of air-conditioning system reality are much lower more than the design load in annual 80% time, operation institute water requirement is also than little many of maximum operation discharge.
The control method that how to design a kind of more energy-conservation circulating pump is the problem that the technical staff will solve.
Summary of the invention
The technical issues that need to address of the present invention have provided the constant pressure frequency conversion energy-saving control method of circulating pump in a kind of central air conditioner system, are intended to solve the above problems.
In order to solve the problems of the technologies described above, the present invention realizes by following steps:
Setting ductwork pressure value (lift) is H
0, pipe network initial water amount is Q
A, initial operating point is A, the rotating speed of pump motor is n
1, the shaft power of operating point A is AH
0OQ
A4 areas that enclosed;
When the pipe network load reduced, ductwork pressure raise, and pressure sensor will detect rising pressure and convert 4 ~ 20mA current signal to and be sent to Fuzzy Controller, after comparison process, export a signal that makes frequency converter frequency reduce, thereby the reduction motor speed be to n
2, the decline of pump rotary speed causes running operating point to descend along the similar operating condition parabola of water pump, just moves to the B point from an A, and the flow and the pressure of water pump output all can correspondingly reduce in this process;
Force value is constant in H in the constant pressure water supply system
0, so pump operating point is again along rotation speed n
2Pairing characteristic curve of pump moves to the C point from a B, raises at this stage pump output pressure, and flow reduces, and water pump operation is at new operating point C point;
Find out the lift H that C is ordered
C, flow Q
CAnd efficiency eta
C, the shaft power of operating point C is CH
0OQ
C4 areas that enclosed.
Compared with prior art, the invention has the beneficial effects as follows: power savings is quite remarkable, and economic benefit is very considerable.
Description of drawings
Fig. 1 is a working curve diagram of the present invention.
The specific embodiment
Below in conjunction with the accompanying drawing and the specific embodiment the present invention is described in further detail:
As seen from Figure 1: the present invention realizes by following steps:
Setting the ductwork pressure value is H
0, pipe network initial water amount is Q
A, initial operating point is A, the rotating speed of pump motor is n
1, the shaft power of operating point A is AH
0OQ
A4 areas that enclosed;
When the pipe network load reduced, ductwork pressure raise, and pressure sensor will detect rising pressure and convert 4 ~ 20mA current signal to and be sent to Fuzzy Controller, after comparison process, export a signal that makes frequency converter frequency reduce, thereby the reduction motor speed be to n
2, the decline of pump rotary speed causes running operating point to descend along the similar operating condition parabola of water pump, just moves to the B point from an A, and the flow and the pressure of water pump output all can correspondingly reduce in this process;
Force value is constant in H in the constant pressure water supply system
0, so pump operating point is again along rotation speed n
2Pairing characteristic curve of pump moves to the C point from a B, raises at this stage pump output pressure, and flow reduces, and water pump operation is at new operating point C point;
Can find out the lift H that C is ordered in the drawings
C, flow Q
CAnd efficiency eta
C, the shaft power of operating point C is CH
0OQ
C4 areas that enclosed.
Investigate the efficiency curve η-Q of water pump,, the regulating working conditions of pump rotary speed must limit within limits, does not just make frequency converter frequency descend lowly excessively, avoids water pump in inefficient section operation.
Water pump power frequency and the contrast of frequency conversion effect:
| Content | The water pump power frequency | Pump variable frequency |
| The electric motor starting mode | Directly start, dash current is big during startup | Soft start, non-impact current during startup |
| The machine operation physical phenomenon | Strong noise, vibration are big, motor body has obvious temperature rise. | Noise, vibration is little, motor body temperature rise phenomenon is not obvious. |
| Mechanical life | Starting changes apart from big, and vibration causes a motor part diversity wearing and tearing big during use, and the pipe resistance is big, and maintenance cycle is short, and mechanical life is short. | Starting changes apart from little, vibrates during use and causes a motor part diversity wearing and tearing little, and the pipe resistance is little, prolongs maintenance and mechanical life 2-3 at least doubly. |
| Annual power saving rate | Do not have | More than 40% |
| Equipment control | Behavior adjustment management | Automation control, unattended |
Cost analysis:
2 of water circulating pump power: 22KW (parallel connection), user mode; 1 opens 1 is equipped with
Annual power saving rate: chilled water pump 48.3%
This water circulating pump whole year operation time is 7560 hours (promptly 24 hours/day, 30 days/month, 10.5 month/year)
Electricity price: $0.95 unit/degree (KW/h)
Can save the electricity charge whole year: power of motor (KW) * rate of load condensate (%) * power saving rate (%) * whole year operation time (hour) * electricity price
Be=75842 yuan/year of 22KW * 100% * 48.3% * 7560h/ * 0.923 yuan/degree.
Principle of the present invention is such:
A: pump rotary speed and flow proportional (Q ∝ n), Q1/Q2=n1/n2
B: the proportional (H=KQ of the quadratic power of pump head and flow
2), H1/H2=(n1/n2)
2
C: the power consumption and the power output on the motor shaft of motor are proportional, (the P ∝ n and the power output on the motor shaft is directly proportional with the cube of rotating speed
3), P1/P2=(n1/n2)
3
Therefore, change rotating speed of motor, pump capacity Q, lift H and shaft power P are changed with corresponding rule.
The rotation speed n of ac motor and supply frequency f have following relation: n=60f (1-s)/p
If the running frequency of motor is lowered to 40HZ by original 50HZ, then the actual speed of motor is approximately reduced to rated speed (n
N) 80%. actual powers when therefore operating in 40HZ be:
P＝Kn
3＝K(0.8n
N)
3＝0.512Kn
N 3＝0.512P
N
Power saving rate=(P
N-P)/P
N=(P
N-0.512P
N)=48.8%
K: proportionality coefficient
P
N: rated power
This shows that when the 40HZ, the power output on the motor shaft has only about half of rated power in theory as water pump operation, power saving rate is 48.8%, and power savings is quite remarkable, and economic benefit is very considerable.
Claims (1)
1. the constant pressure frequency conversion energy-saving control method of circulating pump in the central air conditioner system, realize by following steps:
Setting the ductwork pressure value is H
0, pipe network initial water amount is Q
A, initial operating point is A, the rotating speed of pump motor is n
1, the shaft power of operating point A is AH
0OQ
A4 areas that enclosed;
When the pipe network load reduced, ductwork pressure raise, and pressure sensor will detect rising pressure and convert 4 ~ 20mA current signal to and be sent to Fuzzy Controller, after comparison process, export a signal that makes frequency converter frequency reduce, thereby the reduction motor speed be to n
2, the decline of pump rotary speed causes running operating point to descend along the similar operating condition parabola of water pump, just moves to the B point from an A, and the flow and the pressure of water pump output all can correspondingly reduce in this process;
Force value is constant in H in the constant pressure water supply system
0, so pump operating point is again along rotation speed n
2Pairing characteristic curve of pump moves to the C point from a B, raises at this stage pump output pressure, and flow reduces, and water pump operation is at new operating point C point;
Find out the lift H that C is ordered
C, flow Q
CAnd efficiency eta
C, the shaft power of operating point C is CH
0OQ
C4 areas that enclosed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100359432A CN101556068A (en) | 2008-04-11 | 2008-04-11 | Constant pressure frequency conversion energy-saving control method of recycle pump in central air-conditioning system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100359432A CN101556068A (en) | 2008-04-11 | 2008-04-11 | Constant pressure frequency conversion energy-saving control method of recycle pump in central air-conditioning system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101556068A true CN101556068A (en) | 2009-10-14 |
Family
ID=41174277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008100359432A Pending CN101556068A (en) | 2008-04-11 | 2008-04-11 | Constant pressure frequency conversion energy-saving control method of recycle pump in central air-conditioning system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101556068A (en) |
Cited By (9)
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| CN102251955A (en) * | 2011-04-07 | 2011-11-23 | 渤海大学 | Measuring method for variable speed control operation condition of middle-low special rotating speed pump/fan |
| CN102361434A (en) * | 2011-10-11 | 2012-02-22 | 北京曙光航空电气有限责任公司 | Method for expanding power supply frequency of constant voltage frequency conversion asynchronous motor |
| CN103104509A (en) * | 2013-02-25 | 2013-05-15 | 天津大学 | Obtaining method of variable frequency water pump full working condition operating state |
| CN103154518A (en) * | 2011-04-11 | 2013-06-12 | 富士电机株式会社 | Water supply pump control device |
| CN103299076A (en) * | 2011-01-10 | 2013-09-11 | 威乐欧洲股份公司 | Method for operating a pump that is driven by an electric motor in a power-optimized manner in the event of low volumetric flow rates |
| CN103314217A (en) * | 2011-01-21 | 2013-09-18 | 株式会社荏原制作所 | Water supply device |
| CN105556127A (en) * | 2013-08-14 | 2016-05-04 | 奥尔灿能源股份公司 | Performance map control of centrifugal pumps |
| CN106150998A (en) * | 2015-05-15 | 2016-11-23 | 株式会社荏原制作所 | The control method of pump installation, Long-Range Surveillance Unit and pump installation |
| CN108087259A (en) * | 2016-11-22 | 2018-05-29 | 许继集团有限公司 | A kind of computational methods of frequency conversion water circulating pump power consumption |
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2008
- 2008-04-11 CN CNA2008100359432A patent/CN101556068A/en active Pending
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103299076B (en) * | 2011-01-10 | 2015-04-08 | 威乐欧洲股份公司 | Method for operating a pump that is driven by an electric motor in a power-optimized manner in the event of low volumetric flow rates |
| CN103299076A (en) * | 2011-01-10 | 2013-09-11 | 威乐欧洲股份公司 | Method for operating a pump that is driven by an electric motor in a power-optimized manner in the event of low volumetric flow rates |
| CN103314217A (en) * | 2011-01-21 | 2013-09-18 | 株式会社荏原制作所 | Water supply device |
| CN103314217B (en) * | 2011-01-21 | 2015-12-23 | 株式会社荏原制作所 | Water supply installation |
| CN102251955B (en) * | 2011-04-07 | 2013-06-12 | 渤海大学 | Measuring method for variable speed control operation condition of middle-low special rotating speed pump/fan |
| CN102251955A (en) * | 2011-04-07 | 2011-11-23 | 渤海大学 | Measuring method for variable speed control operation condition of middle-low special rotating speed pump/fan |
| CN103154518A (en) * | 2011-04-11 | 2013-06-12 | 富士电机株式会社 | Water supply pump control device |
| CN103154518B (en) * | 2011-04-11 | 2015-09-09 | 富士电机株式会社 | Feed water pump control apparatus |
| CN102361434B (en) * | 2011-10-11 | 2015-09-09 | 北京曙光航空电气有限责任公司 | The method of expansion constant-pressure frequency converting asynchronous motor frequency of supply |
| CN102361434A (en) * | 2011-10-11 | 2012-02-22 | 北京曙光航空电气有限责任公司 | Method for expanding power supply frequency of constant voltage frequency conversion asynchronous motor |
| CN103104509B (en) * | 2013-02-25 | 2015-01-21 | 天津大学 | Obtaining method of variable frequency water pump full working condition operating state |
| CN103104509A (en) * | 2013-02-25 | 2013-05-15 | 天津大学 | Obtaining method of variable frequency water pump full working condition operating state |
| CN105556127A (en) * | 2013-08-14 | 2016-05-04 | 奥尔灿能源股份公司 | Performance map control of centrifugal pumps |
| CN105556127B (en) * | 2013-08-14 | 2017-06-27 | 奥尔灿能源股份公司 | The comprehensive characteristics curve adjustment of centrifugal pump |
| US10480515B2 (en) | 2013-08-14 | 2019-11-19 | Orcan Energy Ag | Performance map control of centrifugal pumps |
| CN106150998A (en) * | 2015-05-15 | 2016-11-23 | 株式会社荏原制作所 | The control method of pump installation, Long-Range Surveillance Unit and pump installation |
| CN108087259A (en) * | 2016-11-22 | 2018-05-29 | 许继集团有限公司 | A kind of computational methods of frequency conversion water circulating pump power consumption |
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Open date: 20091014 |