Method for controlling at least two fans

Patent metadata

Field	Value
Publication number	US-11486407-B2
Application number	US-201816623865-A
Country	US
Kind code	B2
Filing date	Jul 12, 2018
Priority date	Jul 20, 2017
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A control device and a method for controlling a system having at least two fans ( 1 ) and/or fan groups for generating a defined setpoint value (VG,setpoint, ΔpG,setpoint), wherein, by changing the operating points of at least one fan ( 1 ) depending on which setpoint value is fixedly predetermined, at least one of the fans ( 1 ) is brought to an optimal operating point and thereby the efficiency ηG of the system is increased.

First claim

The invention claimed is:

1. A method for controlling a system comprising a number n of at least two fans and/or fan groups for generating a setpoint value (V G,setpoint , Δp G,setpoint ) of either a fixed volume flow V G,setpoint in the system with a variable pressure increase Δp G,setpoint or a fixed pressure increase Δp G,setpoint in the system with a variable volume flow V G,setpoint , as defined by the following steps:
a) determining the current operating state for each of the fans;
b) determining the power optimization potential for each of the fans as defined according to concrete operating states for which each fan is brought to a power optimized state;
c) comparing the current operating state determined in the aforementioned step a) with the power optimization potential of the fans from step b), to obtain an optimization recommendation with respect to at least one of the fans, and
d) correction of the setpoint value (V G,setpoint , Δp G,setpoint ) by changing the operating state of the at least one of the fans, depending on which setpoint value is fixedly predetermined, thereby, bringing the at least one of the fans to the power optimized state and thereby increasing an efficiency ηG of the system,
wherein in step a), the determination of the current operating state of each of the fans occurs in that at least the volume flow V and the rotation speed n of each fan is determined, and the pressure increase Δpst, the power consumption P and the efficiency ηG are determined as a function of the volume flow and of the rotation speed, which are stored in motor electronics associated with the plurality of fans, and wherein, in the determination of the optimization recommendation for the adjustment of the operating state for the at least one of the fans in step c), includes the fan that makes highest power contribution to air conveyance in the system.

2. The method according to claim 1 , characterized in that step d) occurs in such a manner that a plurality of the fans are brought to the power optimized state.

3. The method according to claim 2 , characterized in that, the efficiency ηG of the system is increased when one or more of the fans are switched off.

4. The method according to claim 1 , characterized in that the efficiency ηG of the system is increased when one or more of the fans are switched off.

5. The method according to claim 1 , wherein, determining the optimization potential in step b) includes identification of an optimized volume flow V opt and an optimized pressure increase Δp opt for each of the fans.

6. The method according claim 5 , wherein, in step c) one of the following occurs:
a. the optimization recommendation in the case of a defined volume flow V G,setpoint to be kept constant consists in carrying out a pressure increase or decrease, depending on whether the optimized pressure increase Δp opt is greater than or smaller than the determined pressure increase Δpst or
b. the optimization recommendation in the case of a defined pressure P G,setpoint to be kept constant consists in increasing or lowering the volume flow, depending on whether the optimized volume flow V opt is greater than or smaller than the determined volume flow V.

7. The method according to claim 6 , wherein steps a) through d) are cyclically repeated until the correction in step d) results in either a targeted total efficiency, a total efficiency optimized with respect to the previous cycle, or a targeted total efficiency that is asymptomatically approached, wherein the cyclic repetition of steps a) through d) are halted at the latest after a predefined number of cycles.

8. The method according to claim 1 , wherein a measurement of power consumption P of each fan occurs before and after the correction in step d), and it is determined whether a total sum of all the power consumptions P of the fans, measured after the correction in step d), was reduced in comparison to the total sum of all the power consumptions P measured before the correction in step d).

9. The method according to claim 8 , wherein if the total sum of all the power consumptions P after the correction in step d) was not reduced, the change in the operating state of the at least one fan that was made in the previously performed optimization step d) is reversed.

10. The method according to claim 9 , wherein steps a) through d) are cyclically repeated until the correction in step d) results in either a targeted total efficiency, a total efficiency optimized with respect to the previous cycle, or a targeted total efficiency that is asymptomatically approached, wherein the cyclic repetition of steps a) through d) are halted at the latest after a predefined number of cycles.

11. The method according to claim 8 , wherein steps a) through d) are cyclically repeated until the correction in step d) results in either a targeted total efficiency, a total efficiency optimized with respect to the previous cycle, or a targeted total efficiency that is asymptomatically approached, wherein the cyclic repetition of steps a) through d) are halted at the latest after a predefined number of cycles.

12. A control device for carrying out a method of controlling a ventilation system comprising a number n of at least two fans and/or fan groups according to claim 1 , wherein the control device comprises the following:
a. an acquisition system configured to determine the volume flow of individual fans and all the fans;
b. a collector for determining of a power optimization potential V opt or Δp st,opt for the respective fans, which can be achieved with constant rotation speed with the rotation speed n;
c. a comparator for comparing the determined operating states with the power optimization potential states determined by the collector in order to obtain a specific optimization recommendation therefrom; and
d. a central ventilation station configured to adjust a respective variable setpoint value by changing the operating state of at least one fan depending on which setpoint value in the system is fixedly predetermined, in order to bring at least one of the fans to a power optimized or optimal operating point and thereby increase the efficiency ηG of the ventilation system.

13. The control device according to claim 12 , characterized in that step d) occurs in such a manner that a plurality of the fans are brought to a power optimized state.

14. The control device according to claim 12 , characterized in that the efficiency ηG of the ventilation system is increased when one or more of the fans are switched off.

15. The control device according to claim 12 , wherein, in step c) one of the following occurs:
a. the optimization recommendation in the case of a defined volume flow V G,setpoint to be kept constant consists in carrying out a pressure increase or decrease, depending on whether the optimized pressure increase Δp opt is greater than or smaller than the determined pressure increase Δpst or
b. the optimization recommendation in the case of a defined pressure P G,setpoint to be kept constant consists in increasing or lowering the volume flow, depending on whether the optimized volume flow V opt is greater than or smaller than the determined volume flow V.

16. The control device according to claim 12 , wherein a measurement of power consumption P of each fan occurs before and after the correction in step d), and it is determined whether a total sum of all the power consumptions P of the fans, measured after the correction in step d), was reduced in comparison to the total sum of all the power consumptions P measured before the correction in step d)

Assignees

• Ebm Papst Mulfingen Gmbh & Co Kg

Inventors

• Fessel Andreas
• Schwab Stefan
• Eberle Walter

Classifications

• F04D25/166 Primary

  using fans · CPC title

• F24F11/46

  Improving electric energy efficiency or saving · CPC title

• F04D25/08

  the working fluid being air, e.g. for ventilation · CPC title

• F04D27/004 Primary

  by varying driving speed · CPC title

• Y02B30/70

  Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating · CPC title