Temperature compensating density relay device and temperature compensation method

Abstract

The application discloses a temperature compensation density relay device and a temperature compensation method, which comprise a pressure gauge and a temperature compensation device; the pressure gauge comprises a second stress tube and a pointer; one end of the second stress tube is connected with a gas pressure container through a pipeline, and the other end of the second stress tube is connected with the pointer; the temperature compensation device comprises a first stress tube, a third stress tube and a temperature difference controller; the first stress tube is internally provided with a first heating device, and one end of the first stress tube is connected with the pointer; the third stress tube is internally provided with a second heating device, and one end of the third stress tube is connected with the pointer; the temperature difference controller is used for controlling the first heating device or the third heating device to heat the corresponding stress tube according to the temperature difference between the temperature of the pressure gauge and the temperature of the gas pressure container; and the resultant force of the stress of the first or third stress tube caused by temperature change and the stress of the second stress tube caused by pressure change drives the pointer to rotate. The application realizes the temperature compensation of on-line detection of gas pressure container leakage.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power equipment, in particular, to a temperature compensation density relay device and a temperature compensation method. BACKGROUND

[0002] The on-line detection of gas pressure container leakage mainly uses density relay. The conventional density relay is composed of a pressure gauge and a temperature compensation device. The pressure gauge is directly connected with the gas pressure container to measure the actual pressure of the gas in the gas pressure container. The temperature compensation device adjusts the indication of the pressure gauge according to the temperature at the pressure gauge to make the pressure gauge display unaffected by the pressure change caused by the temperature change of the gas in the measured gas pressure container, so as to accurately detect the gas amount in the gas pressure container and reflect the leakage of the gas pressure container.

[0003] In the prior art, the tightness of the temperature adjustment spring is adjusted by adjusting the screw provided in the main body of the density relay to realize the temperature compensation of the density relay. The temperature compensation device in the prior art provides compensation according to the temperature at the pressure gauge. The pressure gauge is connected with the gas pressure container, and the heat exchange between the gas in the pressure gauge and the gas in the gas pressure container is extremely slow. Therefore, the temperature compensation provided by the temperature compensation device cannot be consistent with the temperature of the gas in the gas pressure container. In some cases, for example, in winter, the heating dehumidifier in the circuit breaker mechanism box works, causing a large temperature difference between the temperature of the circuit breaker body and the temperature at the pressure gauge, so that the density relay loses its due function, and in the extreme case, the density relay can malfunction.

[0004] The conventional density relay includes a pressure gauge and a temperature compensation device. The density relay and the pressure gauge both reflect the pressure in the gas pressure container. The pressure gauge reflects a real-time pressure related to the temperature of the gas in the gas pressure container, while the density relay reflects a 20℃ converted pressure after the temperature compensation device. In the conventional density relay, the temperature compensation device is a standard spring leaf or a standard self-sealing gas pipe. The standard spring leaf or self-sealing gas pipe produces different tension with the change of its own temperature. The tension and the pressure of the gas in the gas pressure container balance on the real pressure gauge pointer to produce a temperature compensation effect and realize the function of the density relay. In the conventional density relay, the temperature compensation device is often at a different position from the measured gas pressure container, so the temperature compensation device often does not work, or even has a reverse effect and produces false reports. In reality, the density relay and the gas pressure container are required to be installed in the same environment in the power grid, but this is not feasible for large equipment and equipment from different manufacturers. SUMMARY

[0005] In order to solve the problems in the prior art, the application provides a temperature compensation density relay device and a temperature compensation method, which adopts a double temperature compensation device with a heating function to adjust the indication and action of the density relay.

[0006] The application adopts the technical scheme as follows.

[0007] The application provides a temperature compensation density relay device for online detection of leakage of a gas pressure container, which comprises a pressure gauge and a temperature compensation device.

[0008] The temperature compensation device further comprises a third stress tube and a temperature difference controller.

[0009] The temperature difference controller is used for controlling the first heating device or the third heating device to heat the corresponding stress tube according to the temperature difference between the temperature at the pressure gauge and the temperature of the gas pressure container.

[0010] The resultant force of the stress of the first or third stress tube caused by temperature change and the stress of the second stress tube caused by pressure change drives the pointer to rotate.

[0011] The temperature difference controller comprises a gas pressure container temperature measurement end and a pressure gauge temperature measurement end.

[0012] The gas pressure container temperature measurement end is connected to a gas pressure container temperature measurement point and is used for obtaining the temperature of the gas pressure container.

[0013] The pressure gauge temperature measurement end is connected to a pressure gauge temperature measurement point and is used for obtaining the temperature at the pressure gauge.

[0014] The temperature difference controller calculates the temperature difference between the temperature of the gas pressure container and the temperature at the pressure gauge.

[0015] The temperature difference controller comprises a first control end and a second control end.

[0016] The input end of the first heating device in the first stress tube is connected to the first control end, and the input end of the second heating device in the third stress tube is connected to the second control end.

[0017] When the temperature of the gas pressure container is greater than the temperature at the pressure gauge, the first control end outputs an enable signal to the first heating device, and the first heating device is started.

[0018] When the gas pressure container temperature is less than the pressure gauge temperature, the second control end outputs an enable signal to the second heating device, and the second heating device is started.

[0019] After the first heating device is started, the stress generated by the first stress tube positively compensates the stress generated by the second stress tube.

[0020] After the second heating device is started, the stress generated by the third stress tube negatively compensates the stress generated by the second stress tube.

[0021] When the first control end outputs an enable signal to the first heating device, the current input to the first heating device is adjusted according to the temperature difference, so as to control the stress generated by the first stress tube.

[0022] When the second control end outputs an enable signal to the second heating device, the current input to the second heating device is adjusted according to the temperature difference, so as to control the stress generated by the third stress tube.

[0023] The pressure gauge temperature measuring point and the stress tubes are in the same cavity, or the pressure gauge temperature measuring point is arranged at the first stress tube.

[0024] The first stress tube, the second stress tube and the third stress tube are made of the same material, have the same size and the same shape.

[0025] The application further provides a temperature compensation method for the temperature compensation density relay device, which comprises the following steps:

[0026] Step 1: collecting the pressure gauge temperature and the gas pressure container temperature.

[0027] Step 2: heating the first stress tube when the gas pressure container temperature is greater than the pressure gauge temperature, and heating the third stress tube when the gas pressure container temperature is less than the pressure gauge temperature.

[0028] Step 3: the resultant force of the stress generated by the first or third stress tube due to temperature change and the stress generated by the second stress tube due to pressure change drives the pointer of the pressure gauge to rotate, and the pressure gauge display is obtained.

[0029] The pressure gauge display is used as the output of the density relay.

[0030] Compared with the prior art, the single temperature compensation by the first stress tube in the prior art is improved to the double temperature compensation based on the first stress tube and the third stress tube with heating function in the application, the first stress tube realizes temperature positive compensation, the third stress tube realizes temperature negative compensation, and the density relay indication and action based on the temperature difference adjustment and compensation are realized.

[0031] The present application adjusts the pressure gauge indication according to the temperature at the pressure gauge through positive and negative temperature compensation, so that the display of the pressure gauge is not affected by the pressure change caused by the temperature change of the gas in the gas pressure container, thereby accurately reflecting the amount of gas in the gas pressure container, and realizing that the density relay is not affected by the installation position and environment, and accurately detecting the leakage of the gas pressure container online.

[0032] The present application sets two temperature measuring points, one in the density relay body (i.e. at the pressure gauge) and one in the gas pressure container body, and inputs the two temperature measuring signals into the temperature difference controller for temperature comparison. The double temperature measuring points can ensure the accuracy of temperature measurement of the density relay body and the gas pressure container.

[0033] The temperature difference controller is used to control the first heating device or the third heating device to heat the corresponding stress tube according to the temperature difference between the temperature at the pressure gauge and the temperature of the gas pressure container. The temperature difference controller also adjusts the size of the input current of the heating device according to the size of the temperature difference, so that the stress change amount of the corresponding stress tube is controllable, the same device is used to realize the start of the compensation device and the control of the compensation amount, and the size of the input current of each heating device is controlled by the measured temperature difference. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic diagram of a temperature compensation density relay device proposed by the present application;

[0035] Figure 1 The reference signs in the drawings are described as follows:

[0036] 1-first stress tube, 2-second stress tube, 3-third stress tube, 10-first heating device, 30-second heating device, 4-needle, 5-pressure gauge temperature measuring point, 6-gas pressure container temperature measuring point, 7-temperature difference controller, 8-gas pressure container. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. The embodiments described in the present application are only a part of the embodiments of the present application, not all the embodiments. All other embodiments obtained by those skilled in the art without creative labor based on the spirit of the present application are within the protection scope of the present application.

[0038] REFERENCE Figure 1The pressure gauge comprises a second stress tube 2 and a pointer 4, one end of the second stress tube 2 is connected with the gas pressure container 8 through a pipeline, and the other end of the second stress tube 2 is connected with the pointer 4. The pressure gauge is directly communicated with the gas pressure container, and measures the actual pressure of the gas in the gas pressure container. The temperature compensation device comprises a first stress tube 1, the first stress tube 1 is internally provided with a first heating device 10, and one end of the first stress tube is connected with the pointer. When the temperature of the gas pressure container to be measured is the same as the temperature at the position of the pressure gauge, if the pressure of the body gas chamber is increased, the gas is expanded, the pressure is increased, and the container does not exist leakage, the stress of the second stress tube 2 caused by the pressure change drives the pointer 4 to rotate, and the function of the density relay is realized. When the temperature of the gas pressure container to be measured is different from the temperature at the position of the pressure gauge, the starting or stopping of the first heating device 10 is controlled according to the temperature at the position of the pressure gauge. After the first heating device 10 is started, the stress of the first stress tube 1 caused by the temperature change is increased to compensate the stress of the second stress tube 2, so that the combined force of the compensated stress drives the pointer 4 to rotate, and the function of the density relay after temperature compensation is realized.

[0039] The application provides a temperature compensation density relay device for on-line detection of gas pressure container leakage. Figure 1 As shown in the figure, the temperature compensation device further comprises a third stress tube 3 and a temperature difference controller 7, and the third stress tube is internally provided with a second heating device 30. One end of the third stress tube is connected with the pointer, and the combined force of the stress of the first or third stress tube caused by the temperature change and the stress of the second stress tube caused by the pressure change drives the pointer to rotate.

[0040] The temperature difference controller is used for controlling the first heating device or the third heating device to heat the corresponding stress tube according to the temperature difference between the temperature at the position of the pressure gauge and the temperature of the gas pressure container.

[0041] The temperature difference controller comprises a gas pressure container temperature measurement end and a pressure gauge position temperature measurement end; the gas pressure container temperature measurement end is connected with the gas pressure container temperature measurement point 6 and is used for acquiring the temperature of the gas pressure container; the pressure gauge position temperature measurement end is connected with the pressure gauge position temperature measurement point 5 and is used for acquiring the temperature at the position of the pressure gauge; and the temperature difference controller calculates the temperature difference between the temperature of the gas pressure container and the temperature at the position of the pressure gauge.

[0042] The temperature difference controller comprises a first control end and a second control end; the input end of the first heating device in the first stress tube is connected with the first control end, and the input end of the second heating device in the third stress tube is connected with the second control end.

[0043] When the temperature of the gas pressure container is greater than the temperature at the pressure gauge, the first control end outputs an enable signal to the first heating device, and the first heating device is started; after the first heating device is started, the stress generated by the first stress tube positively compensates the stress generated by the second stress tube. When the first control end outputs the enable signal to the first heating device, the current input to the first heating device is adjusted according to the size of the temperature difference, and the stress generated by the first stress tube is controlled, so that the positive compensation and the adjustable positive compensation amount are realized.

[0044] When the temperature of the gas pressure container is less than the temperature at the pressure gauge, the second control end outputs an enable signal to the second heating device, and the second heating device is started; after the second heating device is started, the stress generated by the third stress tube negatively compensates the stress generated by the second stress tube; when the second control end outputs the enable signal to the second heating device, the current input to the second heating device is adjusted according to the size of the temperature difference, and the stress generated by the third stress tube is controlled, so that the negative compensation and the adjustable negative compensation amount are realized.

[0045] In the present application, the single temperature compensation by the first stress tube in the prior art is improved to double temperature compensation based on the first stress tube and the third stress tube, wherein the first stress tube realizes positive temperature compensation, and the third stress tube realizes negative temperature compensation.

[0046] By the positive and negative temperature compensation, the present application adjusts the indication of the pressure gauge according to the temperature at the pressure gauge, so that the display of the pressure gauge is not affected by the pressure change caused by the change of the temperature of the gas in the gas pressure container, and the density relay accurately reflects the amount of the gas in the gas pressure container, and realizes online detection of the leakage of the gas pressure container without being affected by the installation position and the environment.

[0047] Further, the temperature difference controller also adjusts the size of the input current of the heating device according to the size of the temperature difference, so that the stress change amount of the corresponding stress tube is controllable.

[0048] In the non-limiting preferred embodiment, when the temperature of the gas pressure container to be measured is the same as the temperature at the pressure gauge, if the body chamber is boosted and the gas is expanded, the pressure rises, and the container does not exist leakage, the second stress tube 2 drives the pointer 4 to rotate, at this time, the temperature difference controller controls the corresponding heating device to start according to the temperature difference, and the stress of the corresponding stress tube changes with the temperature change, and the second stress tube jointly drives the pointer to rotate, realizes the function of the density relay after temperature compensation, and the display of the pressure gauge is the output of the density relay.

[0049] Further, the temperature measuring point at the pressure gauge is in the same pressure gauge cavity as each stress tube, or the temperature measuring point at the pressure gauge is arranged at the first stress tube, so that the temperature error caused by the position of the temperature measuring point at the pressure gauge is not considered. The temperature measuring point of the gas pressure container is arranged at the gas pressure container.

[0050] In the embodiment of the present application, two temperature measuring points are arranged, one of which is located in the density relay body (i.e., at the pressure gauge), and the other of which is located in the gas pressure container body. Both temperature measuring signals are connected to the temperature difference controller for temperature comparison. The double temperature measuring points can ensure the accuracy of temperature measurement of the density relay body and the gas pressure container.

[0051] The first to third stress tubes are the same in material, size and shape.

[0052] The present application further provides a temperature compensation method for the temperature compensation density relay device, comprising:

[0053] Step 1, collecting the temperature at the pressure gauge and the temperature of the gas pressure container;

[0054] Step 2, when the temperature of the gas pressure container is greater than the temperature at the pressure gauge, heating the first stress tube; when the temperature of the gas pressure container is less than the temperature at the pressure gauge, heating the third stress tube;

[0055] Step 3, the resultant force of the stress of the first or third stress tube caused by temperature change and the stress of the second stress tube caused by pressure change drives the needle of the pressure gauge to rotate, and the display of the pressure gauge is obtained.

[0056] Specifically, the stress of the second stress tube in the pressure gauge caused by pressure change is F2, the stress of the first stress tube caused by temperature change after heating is F1, and the stress of the third stress tube caused by temperature change after heating is F3, which satisfy the following relationship:

[0057] F=F1-F2+F3

[0058] In the formula, F is the resultant force of the three stresses.

[0059] Under the action of the resultant force, the needle rotates, and the display of the pressure gauge is obtained, that is, the output of the density relay.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application. Any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. A temperature compensation density relay device for detecting leakage of a gas pressure vessel in line, comprising a pressure gauge and a temperature compensation device; wherein the pressure gauge comprises a second stress tube and a pointer, one end of the second stress tube is connected to the gas pressure vessel through a pipeline, the other end of the second stress tube is connected to the pointer, and the temperature compensation device comprises a first stress tube, a first heating device is built in the first stress tube, and one end of the first stress tube is connected to the pointer; characterized in that: the temperature compensation device further comprises: a third stress tube and a temperature difference controller; a second heating device is built in the third stress tube, and one end of the third stress tube is connected to the pointer; the temperature difference controller is used for controlling the first heating device or the third heating device to heat the corresponding stress tube according to a temperature difference between a temperature at the pressure gauge and a temperature of the gas pressure vessel; the temperature difference controller comprises: a first control end and a second control end; an input end of the first heating device in the first stress tube is connected to the first control end, and an input end of the second heating device in the third stress tube is connected to the second control end; when the temperature of the gas pressure vessel is greater than the temperature at the pressure gauge, the first control end outputs an enable signal to the first heating device, and the first heating device is started; after the first heating device is started, a stress generated by the first stress tube positively compensates a stress generated by the second stress tube; when the temperature of the gas pressure vessel is less than the temperature at the pressure gauge, the second control end outputs an enable signal to the second heating device, and the second heating device is started; after the second heating device is started, a stress generated by the third stress tube reversely compensates the stress generated by the second stress tube; and a resultant force of the stress generated by the first or third stress tube due to temperature change and the stress generated by the second stress tube due to pressure change drives the pointer to rotate. 2.The temperature compensation density relay device according to claim 1, characterized in that: the temperature difference controller comprises: a gas pressure vessel temperature measurement end and a temperature at the pressure gauge measurement end; the gas pressure vessel temperature measurement end is connected to a gas pressure vessel temperature measurement point and is used for acquiring the temperature of the gas pressure vessel; the temperature at the pressure gauge measurement end is connected to a temperature at the pressure gauge measurement point and is used for acquiring the temperature at the pressure gauge; and the temperature difference controller calculates a temperature difference between the temperature of the gas pressure vessel and the temperature at the pressure gauge. 3.The temperature compensation density relay device according to claim 1, characterized in that: when the first control end outputs the enable signal to the first heating device, the size of the current input to the first heating device is adjusted according to the size of the temperature difference, so as to control the size of the stress generated by the first stress tube; and when the second control end outputs the enable signal to the second heating device, the size of the current input to the second heating device is adjusted according to the size of the temperature difference, so as to control the size of the stress generated by the third stress tube. 4.The temperature compensation density relay device according to claim 2, characterized in that: the temperature at the pressure gauge measurement point and each stress tube are in the same cavity, or the temperature at the pressure gauge measurement point is arranged at the first stress tube. 5.The temperature compensation density relay device according to claim 1, characterized in that: the materials, sizes and shapes of the first to third stress tubes are the same. including: Step 1, acquiring the temperature at the pressure gauge and the temperature of the gas pressure vessel; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 6. A temperature compensation method for a temperature-compensated density relay device, implemented by using the device according to any one of claims 1 to 5, characterized in that, ​ ​ Step 2, heating the first stress tube when the gas pressure vessel temperature is greater than the temperature at the pressure gauge, and heating the third stress tube when the gas pressure vessel temperature is less than the temperature at the pressure gauge; Step 3, the resultant force of the stress of the first or third stress tube due to temperature change and the stress of the second stress tube due to pressure change drives the pointer of the pressure gauge to rotate, and the pressure gauge display is obtained.

7. The temperature compensation method of the temperature compensation density relay device according to claim 6, characterized in that: The pressure gauge display serves as the output of the density relay.

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