Method for operating a wastewater pumping station

Patent metadata

Field	Value
Publication number	US-9719241-B2
Application number	US-201314133938-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 20, 2012
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A method is provided for operating a wastewater pumping station of a wastewater pumping network. The pumping station includes a pump, that starts pumping if a level of a wastewater in a tank exceeds a first wastewater level, and the pump stops pumping if the level of the wastewater in the tank drops below a second level. The method includes determining a magnitude of a parameter (P sys , Q, n, ΔP, P electrical , cos φ, I) expressing the load of the wastewater pumping network. If it is determined that the magnitude of the parameter has passed a specified threshold, the pump is activated to start pumping in an energy optimization mode. A control unit is also provided for the wastewater pumping station of the wastewater pumping network, and a system is provided for centrally controlling a plurality of pumps of wastewater pumping stations in a wastewater pumping network.

First claim

What is claimed is:

1. A method for operating a wastewater pumping station of a wastewater pumping network, the wastewater pumping station comprising at least one pump, wherein the at least one pump starts pumping if a level of the wastewater in a tank of the wastewater pumping station exceeds a first wastewater level, and the at least one pump stops pumping if the level of the wastewater in the tank drops below a second level, the method comprising the steps of:
determining a magnitude of a parameter expressing the load in a common pipeline of the wastewater pumping network;
determining if the magnitude of the parameter expressing the load has passed a specified threshold; and
activating the at least one pump to start pumping in an energy optimization mode if the parameter expressing the load has passed the specified threshold, wherein the specified threshold of the load expressing parameter is determined by measuring or deriving the size or value of the parameter during each of a plurality of activations of the at least one pump to provide a plurality of sizes or values of the parameter, and then selecting or calculating the specified threshold on the basis of the sizes or values.

2. A method according to claim 1 , wherein the parameter comprises a pressure detected in a common outlet pipe of the wastewater pumping network.

3. A method according to claim 1 , wherein the step of activating the at least one pump is performed only if a specified third wastewater level has been met or exceeded.

4. A method according to claim 1 , wherein each pump is driven by an electric motor and the parameter expressing the load is at least one of the following: a system pressure (Psys); a pump flow (Q); a number of pumps (n) active in the system; a differential pressure (ΔP) over the at least one pump; an electrical power (P electrical ) used by the at least one pump; a power factor (cos (φ)) of the at least one electrical motor; and an electrical current (I) of the at least one motor.

5. A method according to claim 2 , wherein in the energy optimization mode if it is determined that the pressure exceeds a specified upper pressure limit, the at least one pump is deactivated.

6. A method according to claim 2 , wherein the method further comprises a step of increasing or decreasing, in the energy optimization mode, the speed of the at least one pump in accordance to the pressure detected.

7. A method according to claim 2 , wherein:
the pressure is a fluid pressure of the wastewater in a common outlet pipe of the wastewater pumping network; and
wherein the pressure is detected by measuring the pressure, by means of a pressure sensor, to measure an absolute pressure or a pressure difference, in the common outlet pipe, to which the wastewater pumping station is connected.

8. A method according to claim 1 , wherein a pressure is determined by determining a pressure difference across the at least one pump, and determining a wastewater level in the tank, the at least one pump being accommodated in the tank.

9. A method according to claim 8 , wherein the step of determining the pressure difference across the at least one pump comprises determining the flow of pumped wastewater based on changes in the wastewater level in the tank, or based on the electric power or speed of the at least one pump.

10. A method according to claim 2 , wherein detecting the pressure comprises determining one or more of the power of a drive motor used for driving the at least one pump and a power factor (cos(φ)).

11. A method according to claim 2 , wherein the method further comprises a step of individually controlling the at least one pump based on the pressure detected by a local pump controller.

12. A method according to claim 1 , wherein the at least one pump is centrally controlled from a central control station of the wastewater pumping network.

13. A method according to claim 1 , wherein the wastewater pumping network comprises a plurality of wastewater pumping stations.

14. A control unit for a wastewater pumping station of a wastewater pumping network comprising a plurality of wastewater pumping stations, at least one of the wastewater pumping stations comprising at least one pump adapted to pump wastewater from a tank to a common outlet pipe of the wastewater pumping network, the control unit being configured to:
control the at least one pump to start pumping if a wastewater level exceeds a first level in the tank, and to stop pumping if the level of the wastewater drops below a second level in the tank;
control the activity of the at least one pump in an energy optimization mode on the basis of a determined parameter expressing the load in the common pipeline of the wastewater pumping network;
determine if a magnitude of the parameter expressing the load has passed a specified threshold;
activate the at least one pump to start pumping in an energy optimization mode if the parameter expressing the load has passed the specified threshold;
activate the at least one pump a plurality of times to provide a plurality of activations of the at least one pump;
measure or derive a size or value of the parameter during each of said plurality of activations of the at least one pump to provide at least a plurality of sizes or values of the parameter; and
determine the specified threshold based on at least said plurality of sizes or values of the parameter.

15. A control unit according to claim 14 , wherein the control unit is further adapted to increase or decrease the speed of the at least one pump on the basis of a pressure determined, wherein the control unit is further configured to activate the at least one pump in said energy optimization mode only if a third wastewater level is met or exceeded and the parameter expressing the load has passed the specified threshold, said third wastewater level being between said first wastewater level and said second wastewater level, said first wastewater level being a maximum wastewater level of the tank and said second level being a minimum wastewater level of the tank.

16. A method according to claim 14 , wherein the at least one pump is started if said parameter is calculated by measurement of a differential pressure of the at least one pump or measurement of a flow through the at least one pump.

17. A wastewater pumping system comprising:
a wastewater pumping network with at least one wastewater pumping station comprising a common pipeline, a tank and at least one pump, the tank being connected to the common pipeline; and
a control unit connected to the at least one pump, the control unit being configured to:
control the at least one pump to start pumping if a wastewater level exceeds a first level in the tank, and to stop pumping if the level of the wastewater drops below a second level in the tank;
control the activity of the at least one pump in an energy optimization mode on the basis of a determined parameter expressing the load in the common pipeline of the wastewater pumping network;
determine if a magnitude of the parameter expressing the load has passed a specified threshold;
activate the at least one pump to start pumping in an energy optimization mode if the parameter expressing the load has passed the specified threshold;
measure or derive a size or value of the parameter during each of a plurality of activations of the at least one pump to provide at least a plurality of measured sizes or values of the parameter; and
determine the specified threshold based on at least said plurality of measured sizes or values of the parameter.

18. A sy

Assignees

• Grundfos Holding As

Inventors

• Nybo Peter Jungklas
• Kallesøe Carsten Skovmose
• Lauridsen Klaus Grønnegård

Classifications

• F04D15/0218

  the condition being a liquid level or a lack of liquid supply · CPC title

• F04D15/029

  for pumps operating in parallel · CPC title

• E03F1/007

  for public or main systems · CPC title

• E03F5/22 Primary

  Adaptations of pumping plants for lifting sewage (wheeled apparatus for emptying sewers or cesspools E03F7/10; pumps, pumping plants, per se F04) · CPC title