CN210922721U

CN210922721U - Device for measuring liquid column differential pressure and quickly inputting steam differential pressure type flowmeter

Info

Publication number: CN210922721U
Application number: CN201921755562.1U
Authority: CN
Inventors: 曾令发; 焦鹏; 孙荣年; 梁文武
Original assignee: Gansu Jiu Steel Group Hongxing Iron and Steel Co Ltd
Current assignee: Gansu Jiu Steel Group Hongxing Iron and Steel Co Ltd
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-07-03
Anticipated expiration: 2029-10-18

Abstract

The utility model discloses a steam differential pressure formula flowmeter measures liquid column differential pressure and drops into device fast connects other branch pipeline on original pressure pipe, and two pressure pipes all connect branch pipeline, install negative pressure stop valve, malleation stop valve on two branch pipelines respectively, and the pipeline after negative pressure stop valve, the malleation stop valve merges into a pipe, merges union coupling working shaft delivery port, and the working shaft water inlet is by the water piping connection storage water tank. The utility model has the advantages that: the steam flow detection device reduces the failure rate and processing time, and is quickly put into use.

Description

Device for measuring liquid column differential pressure and quickly inputting steam differential pressure type flowmeter

Technical Field

The utility model relates to an automatic change instrument control technical field, especially relate to behind the differential pressure formula flowmeter measurement sampling tube blowdown, how to get into user state's device fast.

Background

With the continuous and deep innovation of enterprises, the economic benefits of each unit in the enterprise are independently accounted, and the steam metering work is emphasized by more and more enterprises. The steam metering is related to the statistics and the evaluation of energy sources, is directly related to the economic benefits of steam producing units and steam consuming units, and meanwhile, the steam consuming units correctly control the steam metering amount, so that the steam metering method is greatly helpful for production processes. Therefore, proper selection of the flow meter is particularly important. The existing industrial flowmeters are various in variety, and have been widely used due to the characteristics of simple structure, strong universality, long service life, convenient remote signal transmission and the like.

The theoretical basis for differential pressure flowmeters is the bernoulli equation and the flow continuity equation. When fluid flows through the throttling device, part of pressure energy is converted into kinetic energy to generate a differential pressure signal, and the differential pressure is proportional to the square of the flow. The differential pressure type flowmeter is produced and used according to GB/T2624-1993 that an orifice plate, a nozzle and a Venturi tube for a flow measurement throttling device measure the flow of fluid filled with a round tube, and the principle formula is as follows:

q_m=C/(1-β4)^0.5επ/4d²(2ρΔP)^0.5

in the formula, q_m-mass flow, kg/s;

c-outflow coefficient;

β -diameter ratio, β = D/D (D is the conduit inner diameter);

ε -the coefficient of expandability;

d-orifice diameter of the throttling element, mm;

ρ -fluid density upstream of the restriction, kg/m 3;

Δ P-differential pressure, kPa, generated by the flow of fluid through the orifice.

Can contain moisture or other impurity in the steam conduit in process of production, in order to avoid influencing differential pressure transmitter and detect accurate nature, so lead the blowdown that the pressure system needs the regularity, need be full of the comdenstion water with the pressure sampling tube again after the blowdown at every turn and form and measure liquid column differential pressure, if appear waiting in process of production that the sampling tube is full of the phenomenon, lead to production to receive the influence, bring serious measurement loss. Therefore, the key point is to shorten the time for forming the differential pressure of the differential pressure type flowmeter to measure the liquid column, and effectively ensure the detection rapidity of the instrument device.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a solve above prior art's problem, provided steam differential pressure formula flowmeter and measured liquid column differential pressure and dropped into the device fast to guarantee that steam pressure detecting system drops into use fast, realize the measuring rapidity.

The technical scheme of the utility model: the utility model provides a steam differential pressure formula flowmeter measures liquid column differential pressure and drops into device fast, connects other branch pipeline on original pressure pipe, and two pressure pipes all connect the branch pipeline, install negative pressure stop valve, malleation stop valve on two branch pipelines respectively, and the pipeline after negative pressure stop valve, the malleation stop valve merges into a pipe, merges union coupling working shaft delivery port, and the working shaft water inlet is by water piping connection storage water tank.

The utility model has the advantages that: (1) reasonable structure, convenient installation and the purposes of improving the measurement accuracy, stability and rapidity of the steam pressure detection system. (2) Starting from solving the actual problems on site, the failure rate and the processing time of the steam flow detection device are reduced, and the steam flow detection device can be quickly put into use after overhauling and discharging sewage. (3) The device has the characteristics of rapidity in measurement and convenience in operation and maintenance for steam flow detection and analysis. Avoiding influencing normal production and reducing economic loss.

Drawings

FIG. 1: schematic diagram of original steam differential pressure type flowmeter;

FIG. 2 is a drawing: a schematic diagram of a device for measuring liquid column differential pressure and rapidly inputting by a steam differential pressure type flowmeter;

in the figure: 1-a steam pipeline; 2-a throttling device; 3-primary valve; 4-exhaust valve; 5-a condensation tank; 6-differential pressure transmitter; 7-positive pressure-relief valve; 8-negative pressure-leading valve, 9-balance valve; 10-a pressure guiding pipe; 11-a blow-down valve; 12-negative pressure stop valve; 13-positive pressure stop valve; 14- -water supply pump; 15-a water storage tank; 16-merging tubes.

Detailed Description

The existing differential pressure type flowmeter measures the liquid column differential pressure by condensing the steam in a steam pipeline into liquid state by a condensing tank 5 as shown in figure 1, filling a positive pressure leading pipe and a negative pressure leading pipe to establish the measured liquid column differential pressure, and the process takes 8-24 hours and takes too long time.

For guaranteeing that steam pressure detecting system drops into use fast, the utility model discloses improve former device, like fig. 2, connect other branch pipeline on the pressure pipe way of original basis, branch pipeline is all connected to two pressure pipes 10, installs negative pressure stop valve 12, malleation stop valve 13 on two branch pipelines respectively, and the pipeline after negative pressure stop valve 12, the malleation stop valve 13 merges to be a pipe, merges 16 connection working pumps 14 delivery ports, and 14 water inlets of working pumps are by water piping connection storage water tank (15). The improvement meets the requirement of establishing the differential pressure of the measured liquid column from the sewage discharge to the filling of condensed water in the positive and negative pressure leading pipes, the differential pressure type flowmeter is put into operation again for only 10 minutes, and the problem that the original time for waiting for 8-24 hours is solved.

The utility model discloses an use: considering that the steam pipeline contains moisture and other impurities, the blowdown valve 11 is opened for blowdown treatment, and the blowdown valve 11 is closed after blowdown is completed. The detection device is put into operation again on site, the pressure difference is established step by step on the pressure-leading pipe at the moment, the first step is to make the positive pressure-leading pipe full of condensed water, the negative pressure stop valve 12, the primary valve 3, the positive pressure-leading valve 7 and the negative pressure-leading valve 8 are all closed, meanwhile, the positive pressure stop valve 13 and the exhaust valve 4 are opened (so as to observe whether the pressure-leading pipe is full of condensed water), the water supply pump 14 is started to supply water, the phenomenon that the exhaust valve 4 overflows is observed, and the condensed water is indicated to be full of; and in the second step, a pressure difference is built between the negative pressure tapping pipe, the negative pressure stop valve 12 is opened while the positive pressure stop valve 13 is closed, the negative pressure tapping pipe is filled with condensed water to build the pressure difference, the overflow phenomenon of the exhaust valve 4 is also observed, and at the moment, the negative pressure stop valve 12 is closed and the water supply pump 14 is closed to stop water supply. The rapid investment of the steam differential pressure type flowmeter for measuring the liquid column differential pressure is realized by completing the work, only about 10 minutes are needed from the sewage discharge to the establishment of the measured liquid column differential pressure in the process, and the waiting process of 8-24 hours originally needed is greatly shortened.

Although the device greatly shortens the time for putting the detection device into operation again, the installation and debugging of the device must be reasonable:

1. installation of a standard throttling device:

the requirement for installing the throttling device pipeline. The front and rear straight pipe sections for installing the throttling device are as long as possible in principle, but the engineering is practically impossible, so that the influence of any local resistance on the flow beam is avoided as much as possible by ensuring the front 10D and rear SD of the throttling device (namely the pipe diameter of the front straight pipe section of the throttling device is at least 10 times that of the rear straight pipe section of the throttling device, and the pipe diameter of the rear straight pipe section of the throttling device is at least 5 times that of the throttling device), and particularly, any protruding part is not allowed to exist on the inner wall of one section of the pipeline with the front and rear length. Such as raised gaskets, rough welds, sleeves for temperature sensing elements, etc., and further, do not allow for various valves, bends, etc. to affect the flow stream.

2. Installation of a pressure guiding pipe:

and (5) installing a pressure guiding pipe. The fluid passes through the throttling device and then converts the flow signal of the measured medium into a differential pressure signal, and the differential pressure signal is transmitted to the differential pressure transmitter through two pressure leading pipes, so that the flow is displayed. Whether the pressure guiding pipe can accurately and faithfully transmit a differential pressure signal mainly comes from the accurate design and the correct installation of the pressure guiding pipe. The pressure guiding pipe is laid at the shortest distance as possible, the total length of the pressure guiding pipe is not more than 50 meters, and the corner of the pressure guiding pipe is an even round angle. The pressure guiding pipe is installed to be vertical or form a certain gradient with the horizontal plane, so that gas, moisture, liquid or solid particles accumulated in the pressure guiding pipe can be removed conveniently to influence the accurate transmission of a differential pressure signal. In addition, a sewage discharge valve is additionally arranged, so that periodic discharge is facilitated. The pipe should be far away from the heat source and has anti-freezing and heat-insulating measures, so that smooth and accurate transmission of differential pressure signals is facilitated. The pressure guiding pipe has good sealing performance, and all pressure guiding pipes have no leakage phenomenon.

Claims

1. A steam differential pressure type flowmeter measures liquid column differential pressure and drops into device fast, characterized by: connect other branch pipeline on original pressure leading pipe, branch pipeline is all connected in two pressure leading pipes (10), installs negative pressure stop valve (12), malleation stop valve (13) on two branch pipelines respectively, and the pipeline behind negative pressure stop valve (12), malleation stop valve (13) merges into a pipe, merges pipe (16) and connects working shaft (14) delivery port, and working shaft (14) water inlet is by water piping connection storage water tank (15).