Method for determining the flow of a fluid
First Claim
1. A method of determining the flow rate of a fluid flowing in a pipe, the method comprising the steps of:
- (1) determining an array of time difference reference values, each value in said array defining a measure of the time required for a first temperature measuring probe to cool from a temperature T1, to a temperature T2 as a function of a specified fluid flow rate and fluid temperature;
(2) contacting said first temperature measuring probe with the flowing fluid;
(3) contacting a second temperature measuring probe with the flowing fluid;
(4) heating said first probe to temperature T1 ;
(5) measuring the temperature of said fluid by use of said second probe;
(6) measuring the time required for said first probe to cool from T1 to T2 ; and
(7) interpolating between said values, in said array, to calculate the flow rate corresponding to said cooling time and said fluid temperature.
1 Assignment
0 Petitions
Accused Products
Abstract
The flow rate of a fluid, e.g. hot water, is determined by measuring the temperature of the fluid and the cooling time between two temperature thresholds of a previously heated probe. On the basis of these values, by way of a first interpolation based on a table comprising the cooling times of the probe as a function of different temperatures and flow rates, the cooling times at the temperature measured are calculated for all the flow rates recorded on the table, then, by way of a second interpolation between the values thus calculated which are higher and lower than the value measured, the flow rate corresponding to this value is calculated.
17 Citations
8 Claims
-
1. A method of determining the flow rate of a fluid flowing in a pipe, the method comprising the steps of:
-
(1) determining an array of time difference reference values, each value in said array defining a measure of the time required for a first temperature measuring probe to cool from a temperature T1, to a temperature T2 as a function of a specified fluid flow rate and fluid temperature; (2) contacting said first temperature measuring probe with the flowing fluid; (3) contacting a second temperature measuring probe with the flowing fluid; (4) heating said first probe to temperature T1 ; (5) measuring the temperature of said fluid by use of said second probe; (6) measuring the time required for said first probe to cool from T1 to T2 ; and (7) interpolating between said values, in said array, to calculate the flow rate corresponding to said cooling time and said fluid temperature. - View Dependent Claims (2, 3, 4)
-
-
5. An apparatus for determining the flow rate of a fluid in a pipe comprising:
-
first probe means, immersed in said fluid, for indicating the temperature of said first probe; second probe means immersed in said fluid for measuring the temperature of said fluid T0 ; means for storing an array of time difference values, each value in said array defining a measure of the time required for the first probe means to cool from a temperature T1 to a temperature T2 at a specified fluid flow rate and temperature; means for raising the temperature of said first probe means to a temperature T1 ; means for setting a second temperature value T2 of said first probe means; means for measuring the time which elapses as the first probe means cools from T1 to T2 ; means for interpolating between the time difference values in said array to calculate the flow rate corresponding to the measured values of T0 and said elapsed time. - View Dependent Claims (6, 7)
-
-
8. An apparatus for determining the flow rate of a fluid in a pipe comprising:
-
first probe means, immersed in said fluid, for indicating the temperature of said first probe; second probe means, immersed in said fluid, for measuring the temperature of the fluid, T0 ; microprocessor means for storing an array of time difference values, each value in said array defining a measure of the time required for the first probe means to cool from a temperature T1 to a temperature T2 at a specified fluid flow rate and fluid temperature;
for raising the temperature of said first probe means to a temperature T1 ;
for setting a second temperature value T2 of the first probe means;
for measuring the time which elapses as the first probe means cools from T1 to T2 ; and
for interpolating between the time difference values in the array to calculate the flow rate corresponding to said cooling time and said fluid temperature.
-
Specification