RU2157967C2 - Procedure measuring flow rate of fluid medium - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: procedure can be used for measurement of flow rate of fluid media when measurements are conducted in measurement range below sensitivity threshold of used flowmeter. According to given procedure fluid medium is fed from main line through pressure unit and main line flowmeter to operational load to exclude insensitivity zone in initial measurement range from zero flow rate to sensitivity threshold of main flowmeter from measurement circuit of fluid medium. Portion of flow of fluid medium after main line flowmeter is returned via auxiliary flowmeter and limiting throttle into main line ahead of pressure unit. Flow rate of operational load is found as difference of flow rates via main line and auxiliary flowmeters. Proposed procedure measuring flow rate of fluid medium makes it feasible to shift measurement range of main line flowmeter to required range. EFFECT: shift of measurement range to required range. 1 dwg

Description

 The invention relates to the field of measuring equipment and can be used in systems for measuring the flow of fluid.

 Fluid flow measurement is widely used in various industries, as well as in domestic and special installations. The proposed measurement method can be used in wide application.

 Known and widely used is the method of measuring the flow rate of the fluid, which we adopted as a prototype, in which the fluid is supplied from the line through a pressure device, for example, a pump and a flow measuring device — a flowmeter to the workload (Kremlevsky P.P. Flowmeters and quantity counters. Reference . // L., Engineering, 1989, 702 p.).

 The disadvantage of this method is the presence of a dead zone in the initial measurement range when changing the flow from zero to the sensitivity threshold for known flow meters, in particular for a jet flow meter (V.V. Viktorov, A.M. Kasimov, A.N. Klimov. Inkjet flow meter. A.S. N 1295230), which limits the working area and, therefore, the breadth of applicability of the flow meters. So, for jet flow meters in the case of measuring minimum flow rates, conflicting technical requirements apply - the minimum measured flow rate (and, therefore, the minimum cross section of the supply nozzle) and the maximum allowable pressure drop across the flow meter at the maximum measured flow rate, which limits the scope of such flowmeters.

 The aim of the invention is to expand the scope of fluid flow meters by eliminating the dead zone in the initial measurement range of the flow meter from the measurement process from zero flow rate and above.

 This goal is achieved by the fact that in the method of measuring the flow rate of the fluid, in which the fluid is supplied from the line through the pressure device and the main flow meter to the working load, part of the fluid stream after the main flow meter is returned through the auxiliary flow meter and restriction throttle to the line in front of the pressure device and the flow rate for the workload is defined as the difference in costs through the main and auxiliary flow meters.

 The salient features in the aforementioned combination are: the return of a part of the fluid flow to the line to the pressure device, the restriction of this part of the flow by the throttle and measurement of its auxiliary flow meter, the determination of the flow rate for the working load as the difference in flow rates through the main and auxiliary flow meters.

 The presence of these essential features that distinguish the proposed method from the prototype, gives the claimed object a new property, namely, that the dead zone is excluded from the process of measuring the flow rate of the fluid at the working load in the initial measurement range of the main flow meter and the flow rate can be measured in the range from zero flow rate, which allows us to conclude that the claimed object corresponds to the sign of "significant difference".

 The drawing shows a functional diagram of a device that implements the proposed method. The device comprises: a line 1 for supplying a fluid, a pressure head device 2, a main flow meter 3, a working load 4, an auxiliary flow meter 5, a restrictive throttle 6, a meter 7.

 In a device that implements the proposed method, the fluid from the line 1 is fed through a pressure device, for example, a pump 2 and a main flow meter 3 to a working load 4, and a part of the fluid stream after the main flow meter 3 is returned through the auxiliary flow meter 5 and the restriction throttle 6 to the main 1 to the pressure device 2. In this case, the flow rate of the fluid to the working object is determined as the difference in flow rates through the main 3 and auxiliary 5 flow meters with a meter 7.

 This method of measuring the flow rate of the fluid to the working load 4 allows you to shift the measuring area of the main flow meter 3 to the required range, including the measuring range from zero flow rate and above, and the offset value is determined by the flow rate through the auxiliary flow meter 5, defined by the restrictive throttle 6.

Claims (1)

 A method of measuring a flow rate of a fluid in which a fluid is supplied from a line through a pressure device and a flow meter to a work load, characterized in that a part of the stream of fluid after the line flow meter is returned via an auxiliary flow meter and a restriction throttle to the line in front of the pressure device and the flow rate to the working one the load is defined as the difference in costs through the main and auxiliary flow meters.