Axial flow induced draft fan flow measuring system

Abstract

The utility model relates to a flow measuring system for an axial flow induced draft fan. The flow measuring system comprises a first pressure stabilizer and a second pressure stabilizer which are respectively arranged at an inlet and an outlet of a diffuser, the pressure stabilizer comprises an access pipe, a throttle plate, a branch pipe, an outflow pipe and a static pressure sensor; the outlet end of the access pipe is divided into two paths which are respectively connected with the inlet ends of the first branch pipe and the second branch pipe, and a converging port of the outlet ends of the first branch pipe and the second branch pipe is connected with the inlet end of the outflow pipe; the outlet end of the outflow pipe is connected with the static pressure sensor; the first throttling plate is arranged in the inlet pipe, and the second throttling plate is arranged in the outlet pipe; an inlet end of an access pipe of the first pressure stabilizer is communicated with an inlet of the diffuser, and an inlet end of an access pipe of the second pressure stabilizer is communicated with an outlet of the diffuser; static pressure sensors of the first voltage stabilizer and the second voltage stabilizer are connected with a signal processor, and static pressure parameters of the inlet section and the outlet section are obtained through the static pressure sensors and transmitted to the signal processor to obtain fan flow. The device is simple in structure and stable in measured data.

Description

Technical Field

[0001] The utility model belongs to the technical field of axial flow fans, and in particular relates to a flow measurement system for an axial flow induced draft fan. Background Art

[0002] The proportion of new energy installed capacity has increased dramatically, and the task of thermal power units to play a bottom-line guarantee role has become more arduous, which has put forward higher requirements for thermal power unit equipment. Large thermal power units have become mainstream units, and the three major fans of units above 600MW are all axial flow fans. As an important auxiliary machine of the boiler, the reliability of the fan directly affects the stable operation of the unit.

[0003] Flow rate is a key performance parameter of the fan. Obtaining the fan flow rate parameter is particularly important for understanding the fan operation status. Axial flow induced draft fans convey dusty flue gas, and the measuring tube is easily blocked. Due to factors such as uneven flow field and turbulent pulsation, the fan flow measurement accuracy is low.

[0004] like Figure 1 As shown in the figure, the axial flow fan structure includes a collector 101, a moving blade area, a stationary blade area, and a diffuser 102. The collector 101 and the diffuser 102 are variable cross-section structures. When the airflow passes through the variable cross-section structure, the dynamic pressure and static pressure change. Since the diffuser is downstream of the blade and the distance is relatively close, its internal flow field is affected by the rotation of the blade, and the static pressure fluctuates periodically, affecting the measurement accuracy of the fan flow. Utility Model Content

[0005] The utility model aims to provide an axial flow induced draft fan flow measurement system, which obtains the flow rate by measuring the stable static pressure. The device has a simple structure and stable measurement data.

[0006] The utility model provides an axial flow induced draft fan flow measurement system, comprising a first pressure stabilizer and a second pressure stabilizer respectively arranged at the inlet and outlet of a diffuser;

[0007] The first pressurizer and the second pressurizer both include an inlet pipe, a throttle plate, a branch pipe, an outflow pipe, and a static pressure sensor, the throttle plate includes a first throttle plate and a second throttle plate, and the branch pipe includes a first branch pipe and a second branch pipe;

[0008] The outlet end of the access pipe is divided into two paths and connected to the inlet ends of the first branch pipe and the second branch pipe respectively. The outlet ends of the first branch pipe and the second branch pipe are connected to the inlet end of the outflow pipe; the outlet end of the outflow pipe is connected to the static pressure sensor;

[0009] The first throttle plate is arranged in the inlet pipe, and the second throttle plate is arranged in the outlet pipe;

[0010] The access pipe inlet end of the first pressurizer is connected to the inlet of the diffuser, and the access pipe inlet end of the second pressurizer is connected to the outlet of the diffuser;

[0011] The static pressure sensors of the first and second pressure regulators are connected to a signal processor, and are used to obtain static pressure parameters of the inlet and outlet sections of the diffuser through the static pressure sensors, and transmit them to the signal processor to obtain the fan flow rate.

[0012] Furthermore, the first branch pipe and the second branch pipe form a rectangle, and the inlet pipe and the outlet pipe are arranged opposite to each other in the center.

[0013] Furthermore, the outer layers of the access pipe, branch pipe and outflow pipe are wrapped with thermal insulation cotton.

[0014] Furthermore, the access pipe is fixedly connected to the fan casing.

[0015] Through the above scheme, through the axial flow fan flow measurement system, a pressure stabilizer is arranged at the inlet and outlet of the diffuser. The pressure stabilizer throttles and hedges to obtain a stable static pressure, and the flow is obtained by calculation, which improves the measurement accuracy of the fan flow. The pipeline is wrapped with thermal insulation cotton to solve the problem of measurement tube blockage.

[0016] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the utility model in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the structural diagram of the axial flow fan;

[0018] Figure 2 This is a schematic diagram of the structure of the flow measurement system of the axial flow induced draft fan of the utility model;

[0019] Figure 3 This is a schematic diagram of the structure of the voltage stabilizer of the utility model.

[0020] Numbers in the figure:

[0021] 101-collector; 102-diffuser; 103-stage I moving blades; 104-stage I stationary blades; 105-stage II moving blades; 106-stage II stationary blades; 107-fan casing; 108-inlet section; 109-outlet section; 110-rectifier.

[0022] 21-first stabilizer; 22-second stabilizer; 201-access pipe; 202-first throttle plate; 203-first branch pipe; 204-second branch pipe; 205-outflow pipe; 206-second throttle plate; 207-static pressure sensor; 208-insulation cotton;

[0023] 3- Signal processor. DETAILED DESCRIPTION

[0024] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0025] Ginseng Figure 2 , Figure 3 As shown, this embodiment provides an axial flow induced draft fan flow measurement system, including a first pressure stabilizer 21 and a second pressure stabilizer 22 respectively arranged at the inlet and outlet of the diffuser 102;

[0026] The first pressurizer 21 and the second pressurizer 22 both include an inlet pipe 201, a throttle plate, a branch pipe, an outflow pipe 205, and a static pressure sensor 206. The throttle plate includes a first throttle plate 202 and a second throttle plate 205. The branch pipe includes a first branch pipe 203 and a second branch pipe 204.

[0027] The outlet end of the access pipe 201 is connected to the inlet end of the first branch pipe 203 and the inlet end of the second branch pipe 204 in two ways, and the outlet end of the first branch pipe 203 and the second branch pipe 204 are connected to the inlet end of the outflow pipe 205; the outlet end of the outflow pipe 205 is connected to the static pressure sensor 206;

[0028] The first throttle plate 202 is disposed in the inlet pipe 201 , and the second throttle plate 205 is disposed in the outlet pipe 205 ;

[0029] The inlet end of the access pipe 201 of the first pressurizer 21 is communicated with the inlet of the diffuser 102, and the inlet end of the access pipe 201 of the second pressurizer 22 is communicated with the outlet of the diffuser 102;

[0030] The static pressure sensors 206 of the first pressure regulator 21 and the second pressure regulator 22 are connected to the signal processor 3, and are used to obtain the static pressure parameters of the inlet section 108 and the outlet section 109 of the diffuser 102 through the static pressure sensor 206, and transmit them to the signal processor 3 to obtain (calculate and output) the fan flow.

[0031] In this embodiment, the first branch pipe 203 and the second branch pipe 204 form a rectangle, and the inlet pipe 201 and the outlet pipe 205 are arranged opposite to each other in the center to increase the hedging effect.

[0032] In this embodiment, the outer layer of the access pipe 201, the branch pipe, and the outflow pipe 205 is wrapped with insulation cotton 208 to maintain the temperature of the voltage-stabilizing tube, prevent the flue gas in the voltage-stabilizing tube from low-temperature corrosion, ammonium bisulfate from solidifying, and other blockages in the pipeline, affecting data accuracy.

[0033] In this embodiment, the access pipe 201 is fixedly connected to the fan casing 107 .

[0034] During operation, the flue gas enters the first pressure stabilizer 21 and the second pressure stabilizer 22 from the access pipe 201, and after the pressure reduction and equalization by the first throttle plate 202, the flue gas flows into the first branch pipe 203 and the second branch pipe 204 respectively. The flue gas in the two branches offsets each other, and after offset and mixing, it flows into the static pressure sensor 206 through the second throttle plate 205. After throttling and offsetting, the static pressure sensor 206 obtains stable static pressure parameters, and the fan flow is calculated by the signal processor 3 using the static pressure parameters.

[0035] The axial flow fan flow measurement system arranges a pressure stabilizer at the inlet and outlet of the diffuser. The pressure stabilizer throttles and hedges to obtain a stable static pressure, and the flow is calculated, thereby improving the fan flow measurement accuracy. The pipeline is wrapped with thermal insulation cotton to solve the problem of measurement tube blockage.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. An axial flow fan flow measurement system, characterized in that: It comprises a first pressure stabilizer (21) and a second pressure stabilizer (22) respectively arranged at the inlet and outlet of the diffuser (102); The first pressurizer (21) and the second pressurizer (22) both comprise an inlet pipe (201), a throttle plate, a branch pipe, an outflow pipe (205), and a static pressure sensor (207); the throttle plate comprises a first throttle plate (202) and a second throttle plate (206); and the branch pipe comprises a first branch pipe (203) and a second branch pipe (204); The outlet end of the access pipe (201) is connected to the inlet ends of the first branch pipe (203) and the second branch pipe (204) in two ways respectively; the outlet ends of the first branch pipe (203) and the second branch pipe (204) are connected to the inlet end of the outflow pipe (205); the outlet end of the outflow pipe (205) is connected to the static pressure sensor (207); The first throttle plate (202) is arranged in the inlet pipe (201), and the second throttle plate (206) is arranged in the outlet pipe (205); The inlet end of the access pipe (201) of the first pressurizer (21) is in communication with the inlet of the diffuser (102), and the inlet end of the access pipe (201) of the second pressurizer (22) is in communication with the outlet of the diffuser (102); The static pressure sensors (207) of the first pressure stabilizer (21) and the second pressure stabilizer (22) are connected to the signal processor (3) and are used to obtain the static pressure parameters of the inlet section (108) and the outlet section (109) of the diffuser (102) through the static pressure sensors (207), and transmit them to the signal processor (3) to obtain the fan flow rate.

2. The axial flow fan flow measurement system according to claim 1, characterized in that: The first branch pipe (203) and the second branch pipe (204) form a rectangle, and the inlet pipe (201) and the outlet pipe (205) are arranged opposite to each other in the center.

3. The axial flow fan flow measurement system according to claim 2, characterized in that: The outer layers of the inlet pipe (201), the branch pipe, and the outlet pipe (205) are wrapped with thermal insulation cotton (208).

4. The axial flow fan flow measurement system according to claim 1, characterized in that: The access pipe (201) is fixedly connected to the fan casing (107).

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