Method for determining a through-flow quantity in a fluid delivery system, method for determining an amount of energy of a delivery fluid, fluid delivery system and pump

Abstract

A pump controller or control device for determining a through-flow quantity in a fluid delivery system, in which a fluid is delivered by a pump, the pump including an electromotor operated at a first speed when the electromotor is in operation and the through-flow quantity being determined from a measured motor power and the speed. A method of using the pump controller or control device includes (i) increasing the first speed to a second speed which is greater than the first speed; (ii) determining a second through-flow quantity at the second speed from the motor power and the second speed; (iii) determining a third through-flow quantity from the second through-flow quantity by extrapolation of the second speed to the first speed, wherein the third through-flow quantity is the target variable; and, (iv) reducing the speed back to the first speed once the second through-flow quantity has been determined.

What is claimed is: 
     
         1 . A fluid delivery system comprising:
 a fluid conduit and at least one pump with an electromotor, the pump including a control device that is configured to:   increase an operating speed to a second speed which is greater than a preceding first speed;   determine a second through-flow quantity at the second speed from a power of the electromotor and the second speed;   determine a third through-flow quantity from the second through-flow quantity by extrapolation of the second speed to the first speed, wherein the third through-flow quantity is a target variable; and   reduce the speed back to the first speed once the second through-flow quantity has been determined.   
     
     
         2 . The fluid delivery system according to  claim 1 , wherein the control device is configured to control a step of checking whether a first through-flow quantity determined at the first speed from the motor power and the first speed is below a predetermined limit value and of increasing the speed to the second speed if the check finds that the quantity is below the limit value. 
     
     
         3 . The fluid delivery system according to  claim 2 , wherein the second speed is selected such that the second through-flow quantity is above the predetermined limit value. 
     
     
         4 . The fluid delivery system according to  claim 1 , wherein the first speed is a nominal speed for normal operation of the fluid delivery system. 
     
     
         5 . The fluid delivery system according to  claim 1 , wherein the extrapolation is a linear extrapolation. 
     
     
         6 . The fluid delivery system according to  claim 1 , wherein the second speed is selected as a predetermined multiple of the first speed. 
     
     
         7 . The fluid delivery system according to  claim 1 , further comprising a solar thermal system with at least one solar collector, wherein the fluid conduit comprises the at least one solar collector. 
     
     
         8 . A pump controller for a pump operated by an electromotor in a fluid delivery system, the pump controller being configured to:
 increase pump speed to a second speed which is greater than a preceding first speed;   determine a second through-flow quantity at the second speed from a power of the electromotor and the second speed;   determine a third through-flow quantity from the second through-flow quantity by extrapolation of the second speed to the first speed, wherein the third through-flow quantity is a target variable; and   reduce the speed back to the first speed once the second through-flow quantity has been determined.   
     
     
         9 . The pump controller according to  claim 8 , the pump controller being further configured to check whether a through-flow quantity determined at the first speed from the electromotor power and the first speed is below a predetermined limit value and, if the result of the check is that the quantity is below the limit value, to increase the speed to the second speed. 
     
     
         10 . The pump controller according to  claim 9 , wherein the second speed is selected such that the second through-flow quantity is above the predetermined limit value. 
     
     
         11 . The pump controller according to  claim 8 , wherein the first speed is a nominal speed for normal operation of the fluid delivery system. 
     
     
         12 . The pump controller according to  claim 8 , wherein the extrapolation is a linear extrapolation. 
     
     
         13 . The pump controller according to  claim 8 , wherein the second speed is selected as a predetermined multiple of the first speed.