Method for detecting fluid flow and fluid heat quantity by thermal flow and its application device

Abstract

The method of detecting fluid flow and heat of fluid with heat flow and its application device is to use heat flow sensor to detect the heat Q that the fluid passes through the pipe or wall to the outside of the pipe or wall, according to the principle and calculation formula of fluid heat exchange - when the fluid physical properties Under certain conditions, physical properties such as density and viscosity are determined or only change with temperature. If the tube or wall is constant, its heat transfer shape parameters are determined. The heat transfer Q is only related to the fluid flow rate ω and the temperature difference Δt between the fluid and the tube or wall. Q=F(flow velocity ω, temperature difference Δt); from the detected Q, Δt, according to the existing or calibrated mathematical model Q=F(ω, Δt) of the detection pipe section or detection device, the fluid flow rate ω==f( Q, Δt), so as to determine the flow rate and fluid heat. Compared with other flow and heat detection methods and instruments, it has the advantages of high precision, low cost, stability, non-destructive and simple advantages.

Description

Technical field: [0001] This patent is a method for detecting fluid flow and fluid heat, and its application device is a flow meter for measuring fluid flow and a device for measuring the enthalpy value and enthalpy difference of hot fluid (such as heating water) and cold fluid (such as air-conditioning chilled water) Calorimeter (abbreviated as fluid calorimeter). Background technique: [0002] Existing flow detection methods include: differential pressure, electromagnetic, ultrasonic, turbine, vortex, etc. There are two types of thermal mass flowmeter (Thermal Mass Flowmeter) using the principle of heat transfer 1. Thermal Profile Flowmeter (Thermal Profile Flowmeter) , the principle is: electric heating on the tube wall, the heat transfer of the fluid flow in the tube will change the temperature distribution of the tube wall, and the change of the temperature distribution can be measured to measure the flow rate. 2. Calorimetric Flowmeter, a flowmeter that applies the "K...

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Problems solved by technology

[0003] Features of thermal mass flowmeter: 1. There must be a heating element and a heating control mechanism that directly heats up the fluid or pipe wall; 2. The detected parameter is temperature; 3. At this stage, it can only be used for gas fluid and micro flow Liquid, one of the reasons is that the calorie consumption of liquid is large

[0004] 2004.9.6 By searching the Chinese patent database - using the name "thermal% flowmeter" to retrieve 7 invention patents and 4 utility models applied for at home and abroad, and searching the US patent database - using the title "thermal" and title "flowmeter" 4 patents from 2001 to 2004 were retrieved, the flowmeter products and detection technologies of various countries listed on Chinaflow.com.cn were searched, and various heating websites and heat metering websites were searched. No heat flow was applied (not Temperature) sensing detects the heat transfer between the fluid and the pipe or wall so as to detect the fluid flow and the method for detecting the heat of the fluid; there is no corresponding flowmeter, fluid calorimeter

According to the test report of the data, the existing heating heat meters all use the above-mentioned flow meter plus temperature detection, except for the ultrasonic wave, the other ones can not meet the requirements after half a year of use

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