Method for online calibrating perforated plate-type steam flow measurement system

Abstract

The invention discloses a method for online calibrating perforated plate-type steam flow measurement system, comprising the following steps: equalizing the pressure at the high pressure end and the low pressure end of the perforated plate-type steam flow measurement system, closing a high-pressure end valve and a low-pressure end valve on a balance valve, subsequently draining sewage; connecting a high-pressure soft pipe of the online calibrating device of the perforated plate-type steam flow measurement system and a high-pressure sewage-drainage outlet of the high-pressure sewage-drainage pipe of the steam flow measurement system, connecting a low-pressure soft pipe with a low-pressure sewage-drainage outlet of the low-pressure sewage-drainage pipe of the steam flow measurement system, connecting a pressure connecting soft pipe with a pressure sewage-drainage outlet of the pressure sewage-drainage pipe of the steam flow measurement system; and opening exhaust ports on a differential pressure transmitter used for calibration after filling the condensed water in each sewage-drainage pipe, draining water of the exhaust ports of the differential pressure transmitter used for calibration, subsequently leading the balance valve to recover to the working state, waiting the system for stabilization and subsequently reading the differential pressure value, the pressure value, the display flow value, calculating the practical flow value and correcting the display flow value according to the practical flow value. The method can realize online calibration of the steam flow measurement system, improve the production efficiency and reduce the equipment investment cost.

Description

technical field [0001] The invention relates to the technical field of calibration of a flow measurement system, in particular to a calibration method of a steam flow measurement system. Background technique [0002] Orifice plate steam flow measurement system is also called differential pressure flowmeter. The system is composed of orifice plate, pressure guiding pipe, differential pressure transmitter, pressure transmitter, totalizer and display. The system realizes the measurement of steam flow through indirect measurement, that is, the parameter values ​​on the right side of the classic flow equation are obtained through separate measurement, calculation and table lookup, and then brought into the classic flow equation to calculate the measured flow, which is displayed on the display come out. Since the birth of the orifice plate steam flow measurement system, it has become the most widely used steam flow measurement system with the largest number of installations and t...

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Problems solved by technology

[0003] The existing orifice plate type steam flow measurement system mainly has the following problems: (1) Regular inspection and maintenance of the orifice plate is required (because the disassembly of the orifice plate is more troublesome, usually enterprises only perform inspection and maintenance once after using it for several years, which makes it an influence One of the accuracy factors of measurement results); (2) After the system has been used for a certain period of time, in order to eliminate measurement errors, it is necessary to remove the differential pressure transmitter, pressure transmitter and totalizer from the system and send them to the laboratory (Enterprises without verification capabilities need to send to relevant testing agencies) for calibration

All of the above factors require shutdown operations, which affects production efficiency and increases production costs

In order to ensure that the equipment used in the orifice plate steam flow measurement system does not affect the normal production during the calibration period, the manufacturer usually needs to configure spare parts, among which the pressure transmitter costs thousands of yuan, and the differential pressure transmitter costs 3-4 thousand yuan. A cigarette factory with an annual output of one million boxes needs to prepare nearly a hundred differential pressure transmitters and pressure transmitters, which undoubtedly increases its investment cost

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