GB2432219A

GB2432219A - Determining efficiency of a pump

Info

Publication number: GB2432219A
Application number: GB0622519A
Authority: GB
Inventors: Tony Cowan
Original assignee: ELAINE COWAN
Current assignee: ELAINE COWAN
Priority date: 2005-11-11
Filing date: 2006-11-13
Publication date: 2007-05-16
Also published as: GB0622519D0; GB0522970D0

Abstract

The efficiency of a pump is determined by measuring flow rate of the pump with a first sensor and measuring the energy consumption of the pump with a second sensor. A calculation program calculates pump efficiency using the measured values and additional fixed parameters (e.g. pump type, vertical distance, impeller type etc.). Various parameters indicative of pump efficiency are calculated - input power in optimum conditions, optimum Pumping Index (PI), actual PI, optimum Total Control Index (TCI) and actual TCI. The results of the efficiency calculation are displayed.

Description

1 2432219

PUMP EFFICIENCY MONITOR

The present invention is directed to an apparatus for monitoring the efficiency of pumps, and in particular pumping systems used in pumping station applications.

The purpose of a pump is to move a fluid from one location to another.

The purpose of pumping systems is to control the movement of fluid. The purpose of pumping systems in pumping stations is to move fluid, e.g. water or waste water, from a source to a point of delivery. In particular, the pumping systems are usually used to transfer water from a lower point in the system to a higher point, where gravitational effects interfere with the water movement. In the context of this application, "pump" is taken to encompass a single pump, multiple pumps, and a pump with its associated pipework and control systems.

The input energy in most pumps is electrical energy. The pump motor * ,* converts this electrical energy into mechanical energy, and the mechanical ::::: energy is converted into hydraulic energy by the pump. These energy conversion steps are not 100% efficient as energy is inevitably lost during the changes between electrical, mechanical and hydraulic energy.

Reasons for these inefficiencies may include variable speed drive losses, motor losses, pump losses and also pipework losses in the pipes of the : system. **.I * S...

Until now, the quantification of these losses required the taking of manual readings of various performance characteristics of the pump. These readings are then used to manually calculate the specific power consumed for the flow rate achieved by the pump. However, such readings do not give a ready indication of the operating efficiency of the pump and indeed efficiency indicators are not provided in known monitoring arrangements.

Instead, efficiency indicators must be manually calculated by an operator.

The taking of performance readings and calculation of efficiency ratings is a time consuming process for a pumping station operator. The time taken to carry out these checks could be better utilised by the operator on other aspects of the pumping station. In addition, for comparison of data over a long period of time, all of the calculations and data must be filed away so that they can be retrieved for analysis at a later date. Again, this relies on the operator to have a suitable filing or storage system from which data can be retrieved.

It is an aim of the present invention to obviate or mitigate one or more of these disadvantages.

According to a first aspect of the present invention, there is provided a pump efficiency monitoring apparatus comprising: * *, a first sensor adapted to monitor the flow rate from a pump; a second sensor adapted to monitor the power consumption of the 20 pump; a data receiving means adapted to receive performance data from the first and second sensors; * . a data storage means adapted to store the steps of a pump efficiency calculation program and parameter data relating to the pump; **s* a data processing means adapted to apply the calculation program to the performance data and parameter data to obtain an efficiency value for the pump; and a display means for displaying the results of the calculation program.

Preferably, the apparatus further comprises data input means adapted to permit manual input of the parameter data. Alternatively, the parameter data may be inputted to the data storage means from an external source.

Preferably, the data storage means is further adapted to store the results of the calculation program.

Preferably, the data processing means is further adapted to compare the results of the calculation program with previous results held in the data storage means. Preferably, the display means is adapted to display the comparison.

Preferably, the monitoring apparatus further comprises a transmission means adapted to transmit control signals from the data processing means to the pump.

According to a second aspect of the invention, there is provided a method : * of determining the efficiency of a pump, the method comprising the steps of: storing a pumping efficiency calculation program on a data *:*. processing means; inputting parameter data concerning the pump to the data processing means; transmitting performance data from a first sensor adapted to *... 25 monitor the flow rate of the pump to the data processing means; transmitting performance data from a second sensor adapted to monitor the power consumption of the pump to the data processing means; calculating the efficiency of the pump by inputting the performance data into the stored calculation program; and displaying the results of the calculation step on a display means.

Preferably, the parameter data provided during the inputting step is taken from the group comprising one or more of specific head, pump type and impeller type.

Preferably, the calculating step also includes the calculation of the specific volume of liquid pumped by the pump per kilowatt hour of power consumed.

Preferably, the displaying step includes displaying the results of both the specific volume and efficiency calculations made during the calculation step. The displaying step may also include displaying the result of the efficiency calculation by way of a visual indicator, such as colour-coding.

The method may also include the step of storing the results of the calculation step on a data storage means. The method may also include * ** the step of comparing the stored results with previously stored results.

The results of the comparison may be displayed on the display means.

Preferably, the method further comprises the step of transmitting a control signal to the pump in response to the results of the calculation step. ** *

A preferred embodiment of the present invention will now be described, by way of example only, in which: Figure 1 is a schematic view of an apparatus for monitoring a pump; and Figure 2 is a flowchart showing the steps taken by a data processing means of the apparatus.

Figure 1 schematically shows an apparatus in accordance with the present invention. The apparatus, generally designated 10, is powered by an external power supply 11 and comprises a data receiving means 12 which is preferably in the form of one or more connectors to which first and second sensors 14,16 are attached. The data receiving means 12 allows data from the first and second sensors 14,16 to be transmitted to the apparatus 10. The first and second sensors 14,16 are positioned in a pumping system (not shown) in order to supply the apparatus 10 with data concerning the performance of a pump. The first sensor 14 is connected to a flowmeter (not shown) downstream of a pump and provides data concerning the flowrate from the pump. The second sensor 16 is connected to the power supply (not shown) for the pump and provides data concerning the electrical power being consumed by the pump. The data receiving means 12 is shown receiving data from only two sensors, but it will be understood that the receiving means 12 could be adapted to receive data from more than two sensors if necessary. In such circumstances, additional connectors could be provided on the apparatus. *

The data receiving means 12 supplies the data from the sensors 14,16 to a data processing means 18. The data processing means 18 is preferably a microprocessor-based device which processes the data received by the apparatus 10. In two-way communication with the data processing means 18 is a data storage means 20. The data storage means 20 is preferably

S

a random access memory (RAM) and stores various calculation steps for the calculation of the efficiency of the pump, as will be explained in more detail below. The data storage means 20 may also store the results of the calculations if desired for comparison in the future.

The apparatus 10 may also optionally comprise a data input means 22 in communication with the data processing means 18 and the data storage means 20. The data input means may be, for example, a number of push buttons on the exterior of the apparatus, or else it may be a keyboard connected to the remainder of the apparatus. Alternatively, the data input means may be external of the apparatus and in communication therewith.

The data input means 22 can be used to input into the apparatus 10 parametric data relating to particular parameters, variables or characteristics of the specific pump being monitored, more detail on which will be given below. Alternatively, the data processing means 18 could be pre-programmed with the parameters of the pump, or else this data may be already stored in the data storage means 20, if the relevant details of the pump are known in advance. The data input means 22, or external data input means, is also used by the operator at each of the decision steps of the process described with reference to Figure 2 below, where operator input is required.

The apparatus also has a display means 24 which displays the results of the calculations performed by the data processing means 18. The display * ** may simply be alphanumeric, but preferably the display is colour-coded for ease of interpretation. The display could give the results in a bar chart form, with the colour of the bar chart indicating the relative efficiency of the pump, e.g. green for optimum performance, yellow for acceptable performance and red for undesirable performance. The colour coding alerts an operator when pump efficiency drops. *... *.S.

25 Figure 2 is a flow chart showing the steps taken by the data processing means 18 when the apparatus 10 is in operation. From the start step 100, the next step is decision step 102 in which the processing means determines the fixed parameters relating to the pump which have either been manually inputted via the data input means 22 or are already stored in the data storage means 20. These parameters can include the head (i.e. vertical distance from source to point of delivery) in metres for which the pump needs to lift the water or waste water, the type of pump being monitored, and the type of impeller being used by the pump. Once the processing means determines that parameter data is present it assimilates this data at step 103, before reaching decision step 104.

At step 104, the processing means determines whether any data is being received from the sensors in the pumping system via the data receiving means 12. If not, the process returns to decision step 102 to recommence the procedure. If neither parameter data nor sensor data is located by the processing means within a predetermined time period, the processing means can optionally be programmed to shut down the apparatus in order to save power.

If sensor data is received, this data is assimilated by the processing means at step 106. Once the parameter and sensor data has been located, the processing means carries out a first calculation at step 108.

* In this calculation step 108, the processing means first calculates the optimum input power P required to drive the pump motor, using the formula:

S * * . * S.

PoptQdesxHsxgxp S. S Where *I.. * S**S

P0 is the input power in optimum conditions; Odes is the desired flowrate (m3/s); Hs is the static head (m); g is gravity (m2/s); and p is density of water (kg/rn3).

P0 is the optimum input power in kW required to achieve the desired flow rate 0, assuming there are no losses in the system.

The processing means then applies a second formula: Plop (Odes X 36OO)/P3 where Pl0, is an optimum Pumping Index, or specific volume, value expressed in m3/kWhr, again assuming no losses in the system. As the P1 value is expressed in m3/kWhr, it indicates the volume of water pumped per kilowatt hour of energy consumed with no losses in the system.

Following these calculations, the processing means applies a further formula to calculate the actual Pumping Index based upon the data received by the data receiving means from the pump sensors, namely: * ** Plact = (QactX 3600)/Pact * * where * S * S * I ** QactIS the flow rate measured by the flow sensor 14; and Pact is the power Consumption measured by the power sensor 16. S.. *5I*

*..* 25 The optimum Pt value can be displayed on the display means 24 alongside the actual P1 value to illustrate the relative performance of the pump in real time.

After calculating the optimum and actual Pumping Indices, the processing means carries out a second set of calculations at step 110. This second calculation step 110 takes the Pumping Indices and applies the following formula: TC0 = Pl01 x Hs where TC01 is an optimum Total Control Index (id), or efficiency, value.

Unlike the P1 value comparison, which illustrates the real time performance of the pump in isolation, the TCI value is an illustration of how the efficiency of the pump compares globally with other pumps. The optimum TCI value for any pump, assuming no losses, is 367 m4/kWhr. This optimum TCI value is a constant and is therefore the same whatever the pump being monitored.

The processing means then applies the formula TCact Plact X Hs * *, in order to determine the actual TCI, or efficiency, value of the pump being ** monitored. The actual and optimum TCI values can then be compared to *e*. . determine the overall operating efficiency of the pump.

After the calculation steps 108,110, the results of the calculations are : displayed by the processing means on a display means at step 112. As * described above, the display means displays the P1 and TCI values. The ** * *..: actual TCI value is preferably displayed in the form of a colour-coded bar s.. 25 graph, showing the actual TCI value relative to the optimum TCI value of 367m4/kWhr. This allows an operator to determine at a glance how efficiently the pump is performing in comparison to the optimum TCI value, with for example green indicating an optimum efficiency band, yellow an acceptable efficiency band, and red an unacceptable efficiency band.

If desired, the processing means can store the results of the monitoring for future reference. At decision step 114, the processing means determines whether the operator would like the results to be stored. If the answer is yes, the processing means sends the results to the data storage means 20 at step 116. The operator is given the opportunity to compare the current results with previously stored results at decision step 118, and those results can be displayed by the processing means at step 120 if the answer is in the affirmative.

If the operator does not wish to store the results at step 114 and answers no, then the processing means moves to decision step 122 where it determines whether to shut down or continue processing. If the operator does not wish to compare results at decision step 118, this will also lead the processing means to decision step 122. Similarly, the processing means will also arrive at this step 122 once the comparison results have been displayed at step 120.

: * If the processing means is either instructed manually to shut down, or else **I. . . . a predetermined penod of time has passed without either any manual *S.. . . . . instructions or data being received, the processing means will shut down at termination step 124. Alternatively, if manual instructions to continue or new data is received, the processing means will return to decision step 102 at commence the procedure again. *. I

I ***. *I..

... 25 The present invention allows the performance of a pump to be automatically monitored without calculation steps being undertaken manually by an operator. It can display both a specific volume level alongside an efficiency indicator value that instantaneously indicates the efficiency level of a pump and when the pump is performing below acceptable levels. By monitoring both power consumption and flow rate directly, the efficiency of the pump can be clearly determined. Comparing power consumption to flow rate allows fluctuations in these values to be quantified. For example, if flow rate is decreasing whilst power consumption is increasing, then the pump clearly is experiencing a problem which must be investigated. By providing a data storage capability, the present invention also allows historic performance results to be compared with current results.

The present invention can also be adapted to adjust the performance of the pump(s) being monitored. By adding a transmitting means to the monitoring apparatus, the apparatus can send control signals from the processing means to the control system of the pump(s) in response to the efficiency results which the apparatus determines. By way of an example, after calculating the pumping efficiency of a pump the efficiency of the pump is seen to be below desirable levels. In response, the processing means can transmit a signal to the control system of the pump to adjust one or more parameters relating to the pump (e.g. pump motor speed).

* ,, By providing the means for the processor to communicate with the control system of the pump, the apparatus can not only monitor, display and 20 record the efficiency of the pump, but can also ensure that components of the pump can be immediately and remotely adjusted to improve the efficiency of the pump itself. I. *

This and other modifications and improvements may be incorporated *I..

without departing from the scope of the invention.

Claims

CLAIMS: 1. A pump efficiency monitoring apparatus comprising: a first

sensor adapted to monitor the flow rate from a pump; a second sensor adapted to monitor the power consumption of the pump; a data receiving means adapted to receive performance data from the first and second sensors; a data storage means adapted to store the steps of a pump efficiency calculation program and parameter data relating to the pump; a data processing means adapted to apply the calculation program to the performance data and parameter data to obtain an efficiency value for the pump; and a display means adapted to display the results of the calculation program.

2. The apparatus of Claim 1 further comprising a data input means, * *, wherein the data receiving means is further adapted to receive the parameter data from the data input means.

3. The apparatus of Claim 1, wherein the data receiving means is further adapted to receive the parameter data from an external source. * . S. *

: 4 The apparatus of any preceding claim, wherein the data storage ... 25 means is further adapted to store the results of the calculation program.

5. The apparatus of Claim 4, wherein the data processing means is further adapted to compare the results of the calculation program with previous results held in the data storage means.

6. The apparatus of any preceding claim, further comprising a transmission means adapted to transmit control signals from the data processing means to the pump being monitored.

7. The apparatus of Claim 6, wherein the transmission means transmits control signals in response to the results of the calculation program.

8. A method of determining the efficiency of a pump, the method comprising the steps of: storing a pumping efficiency calculation program on a data processing means; inputting parameter data concerning the pump to the data processing means; transmitting performance data from a first sensor adapted to monitor the flow rate of the pump to the data processing means; transmitting performance data from a second sensor adapted to * .. monitor the power consumption of the pump to the data processing means; 20 calculating the efficiency of the pump by inputting the performance data into the stored calculation program; and displaying the results of the calculation step on a display means. *. I

9. The method of Claim 8, further comprising the step of transmitting a * control signal to the pump in response to the results of the calculation step.

10. The method of either Claim 8 or Claim 9, wherein the parameter data provided during the inputting step is taken from the group comprising one or more of specific head, pump type and impeller type.

11, The method of any of Claims 8 to 10, wherein the calculating step also includes the calculation of the specific volume of liquid pumped by the pump per kilowatt hour of power consumed.

12. The method of Claim 11, wherein the displaying step includes displaying the results of both the specific volume and efficiency calculations made during the calculation step.

13. The method of any of Claims 8 to 12, wherein the displaying step includes displaying the result of the efficiency calculation by way of a colour-coded visual indicator.

14. The method of any of Claims 8 to 13, further comprising the step of storing the results of the calculation step on a data storage means.

15. The method of Claim 14, further comprising the step of comparing * the stored results with previously stored results. Sq **S. * ***

 20 16. A pump efficiency monitoring apparatus as hereinbefore described with reference to the accompanying drawings.

I

* I. *** e 17. A method of determining the efficiency of a pump as hereinbefore I, * described with reference to the accompanying drawings. * I