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A heat meter heat measurement and calculation principles
Published on:2015-1-9 9:33:31 Hits:

Abstract more detailed description of the principles and methods of measurement of heat several common heat measurement. After analyzing and comparing proposed measurement method using k-factor compensation, to achieve the temperature and pressure coefficients k online compensation, with higher measurement accuracy. gives specific examples of calculations and results.

Keywords heat measurement calorimeter thermal coefficient online compensation

For a long time, China's urban residents in the northern region in general by heating with a hot residential area instead of the actual heat metering and charging, causing the user awareness of energy conservation is poor, resulting in a waste of resources. The apparent lack of scientific measurement methods, while Europe and other developed countries in the eight beginning of the 1980s, a widespread use of heat meters, heat company calorimeter as a basis for valuation fees and means energy savings of 20% to 30% as a basic measure of building energy efficiency, China's Ministry of Construction has heat metering and charging included in the "building Energy Efficiency" Ninth Five "Plan and 2010 plan." Therefore, developed for heating denominated calorimeter imperative.

Calorimeter general should have the following technical requirements [1]:

① overall accuracy of a four standard OIML R75 regulations;

② flowmeter part accuracy, error <3%;

③ platinum resistance temperature sensor temperature measurement devices in accordance with IEC standard 751 and an exact match, when the supply and return water temperature difference within 6 ℃, the measurement error of <0.1 ℃;

④ hot flame and heat meters have revised version of the mass density function, the error is less than 0.5%;

⑤ micro-power design, built-in battery can work continuously for five years.

Now foreign calorimeter technology Chinese market matures, high degree of standardization, but expensive. Our demand for heat meters large, developed a low-cost, in line with international standards calorimeter is the trend. In this paper, based on the principle of heat meters heat measurement, introduces several common heat measurement methods, analysis and comparison of the advantages and disadvantages are discussed in detail heat measurement method compensation coefficient k, the method to achieve the temperature coefficient k and pressure online compensation, which has a high accuracy.

A heat measurement principle

Calorimeter is a suitable measure of the heat exchange loop, the heat transfer liquid heat absorbed or converted instruments, heat meters with legal units of measurement display calories [1]. Calorimeter, also known as heat meters, heat Totalizer, both for measuring heat heating system can measure heat absorption cooling system.

A pair of temperature sensors were installed on the heat transfer fluid through the pipe upstream and downstream pipe, flow meter installed on the fluid inlet or return pipe (flow meter installed at different locations, the final measurement results are different), the meter emits pulse signal proportional to the flow, temperature sensor gives a temperature difference between the analog signal representation, heat meters collect signals from the three-way sensor, use the formula to calculate the heat Totalizer heat exchange systems available.


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