A temperature-controlled constant-speed sampling device for chemical water in power plants

Abstract

An embodiment of the present disclosure provides a temperature-controlled constant-speed sampling device for chemical water in a power plant, comprising: a sampling container, provided with a liquid inlet and an overflow hole; a sampling tube, one end of which is connected to the liquid inlet and the other end of which is connected to a sampling port of a chemical water pipeline; a heating device, which is arranged in the sampling container; a first temperature measuring device, which is arranged in the sampling tube at a position close to the sampling port of the chemical water pipeline, and the first temperature measuring device measures a first measurement temperature of the chemical water sample; a second temperature measuring device, which is arranged in the sampling container and is used to measure a second measurement temperature of the chemical water sample in the sampling container; a PID controller, which is respectively connected to the first temperature measuring device, the second temperature measuring device and the heating device; wherein the first measurement temperature is used as a set value of the PID controller, and the second measurement temperature is used as a controlled variable of the PID controller, and the PID controller controls the heating device based on the difference between the set value and the controlled variable to adjust the temperature of the chemical water sample in the sampling container.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of sampling equipment, and specifically relate to a temperature-controlled constant-speed sampling device for chemical water in a power plant. Background Art

[0002] In the chemical water system of a power plant, it is necessary to measure the conductivity, sodium element, silicon element, pH, oxygen content, etc. of the operating water in real time to determine whether the water standard meets the specified range during the operation of the unit. The pH measuring device is an important basis for measuring water quality. The measurement generally takes a sampling tube directly from the pipe to be measured, and then passes it directly to the measuring probe. After the measurement, the water sample is discharged to the wastewater tank. Because most sampling tubes are long, the temperature will be inconsistent with the original temperature during the period, and the flow rate is not stable, resulting in many bubbles during measurement, which affects the measurement.

[0003] The problems encountered in actual production are:

[0004] In actual measurements, the flow rate in the pipeline will change according to the water demand, thereby generating bubbles that affect the accuracy of pH measurement.

[0005] Because most pH sampling tubes are long, the temperature during the period will be inconsistent with the original temperature, which will lead to inaccurate temperature compensation in the pH measurement calculation and thus cause large measurement errors. Summary of the invention

[0006] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a temperature-controlled constant-speed sampling device for chemical water in a power plant.

[0007] One aspect of an embodiment of the present disclosure provides a temperature-controlled constant-speed sampling device for chemical water in a power plant, comprising:

[0008] A sampling container is provided with a liquid inlet and an overflow hole;

[0009] A sampling tube, one end of which is connected to the liquid inlet hole and the other end of which is connected to the sampling port of the chemical water pipeline;

[0010] A heating device is arranged on the sampling container;

[0011] A first temperature measuring device is arranged at a position of the sampling tube close to the sampling port of the chemical water pipeline, and the first temperature measuring device is used to measure a first measurement temperature of the chemical water sample at the sampling port of the chemical water pipeline;

[0012] A second temperature measuring device, disposed in the sampling container, for measuring a second measurement temperature of the chemical water sample in the sampling container;

[0013] a PID controller, electrically connected to the first temperature measuring device, the second temperature measuring device and the heating device, respectively;

[0014] The first measured temperature is used as a set value of the PID controller, the second measured temperature is used as a controlled variable of the PID controller, and the PID controller controls the heating device based on the difference between the set value and the controlled variable to adjust the temperature of the chemical water sample in the sampling container.

[0015] Optionally, along the height direction of the sampling container, the overflow hole is arranged above the liquid inlet hole.

[0016] Optionally, the sampling container comprises an outer tube, an inner tube and a tube cover, the inner tube is arranged in the outer tube, and the tube cover is detachably arranged at the tube opening of the outer tube;

[0017] Wherein, the heating device is arranged on the outer periphery of the inner cylinder.

[0018] Furthermore, it also includes: a first control valve, which is arranged on the sampling tube, and the first control valve is used to control the on-off of the chemical water sample in the sampling tube.

[0019] Furthermore, it also includes: a second control valve and a liquid guide tube; the sampling container is provided with a liquid outlet;

[0020] Among them, one end of the liquid guide tube is connected to the liquid outlet, and the other end is connected to the conductivity measuring device; the second control valve is arranged on the liquid guide tube, and is used to control the on-off of the chemical water sample in the liquid guide tube.

[0021] Furthermore, it also includes: an overflow pipe, one end of which is connected to the overflow hole, and the overflow pipe is used to conduct the chemical water sample overflowing from the overflow hole.

[0022] Furthermore, it also includes: a heat-insulating layer, which is arranged on the outer periphery of the outer cylinder.

[0023] The beneficial effects of the embodiments of the present disclosure include:

[0024] In the present disclosure, by setting an overflow hole, the chemical water sample in the sampling container that is higher than the overflow hole can be discharged, and the liquid level in the sampling container is maintained constant, thereby ensuring that the gravity of the liquid in the sampling container is constant, so as to ensure that the speed at which the chemical water sample is discharged from the sampling container is constant, and ensure the accuracy of the pH measurement. In addition, by using a PID controller to control the heating device, the chemical water sample in the sampling container can be heated to the same temperature as in the chemical water pipeline, thereby effectively controlling the measurement error caused by temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1The present invention is a schematic structural diagram of a temperature-controlled constant-speed sampling device for chemical water in a power plant according to an embodiment of the present invention.

[0026] In the figure, 1. chemical water pipeline; 2. sampling tube; 3. first temperature measuring device; 4. cylinder cover; 5. overflow pipe; 6. liquid guide tube; 7. second control valve; 8. sampling hose; 9. first control valve; 10. overflow hole; 11. sampling container; 12. liquid outlet hole; 13. second temperature measuring device. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] The following is a further detailed description of the implementation methods of the present application in conjunction with the accompanying drawings and examples. The detailed descriptions and drawings of the following examples are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments. In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "multiple" is more than two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inside", "outside", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the error tolerance range. "Parallel" is not parallel in the strict sense, but within the error tolerance range.

[0029] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0030] PH measurement usually takes a sampling tube directly from the pipe to be measured, and then passes it directly to the measuring probe. After measurement, the water sample is discharged to the wastewater tank. Because most sampling tubes are long, the temperature will be inconsistent with the original temperature, and the flow rate will be unstable, resulting in many bubbles during measurement, thus affecting the measurement.

[0031] The present disclosure adopts the following solution to achieve the purpose of controlling the inlet flow rate of the conductivity measuring device to be constant.

[0032] like Figure 1As shown, a temperature-controlled constant-speed sampling device for chemical water in a power plant is provided. The sampling device comprises a sampling container 11, a sampling tube 2, a heating device, a first temperature measuring device 3, a second temperature measuring device 13 and a PID controller.

[0033] The sampling container 11 is provided with a liquid inlet and an overflow hole 10, one end of the sampling tube 2 is connected to the liquid inlet, and the other end is connected to the sampling port of the chemical water pipeline 1. The heating device is provided in the sampling container 11.

[0034] The first temperature measuring device 3 is arranged at the sampling port of the sampling tube 2 close to the chemical water pipeline 1, and the first temperature measuring device 3 is used to measure the first measurement temperature of the chemical water sample at the sampling port of the chemical water pipeline 1. The second temperature measuring device 13 is arranged in the sampling container 11, and is used to measure the second measurement temperature of the chemical water sample in the sampling container 11. The PID controller is electrically connected to the first temperature measuring device 3, the second temperature measuring device 13 and the heating device respectively.

[0035] The first measured temperature is used as the set value of the PID controller, and the second measured temperature is used as the controlled variable of the PID controller. The PID controller controls the heating device based on the difference between the set value and the controlled variable to adjust the temperature of the chemical water sample in the sampling container 11.

[0036] In the present disclosure, by setting the overflow hole 10, the chemical water sample in the sampling container 11 that is higher than the overflow hole 10 can be discharged, and the liquid level in the sampling container 11 is maintained constant, thereby ensuring that the gravity of the liquid in the sampling container 11 is constant, so as to ensure that the speed at which the chemical water sample is discharged from the sampling container 11 is constant, and ensure the accuracy of the pH measurement. In addition, by using a PID controller to control the heating device, the chemical water sample in the sampling container 11 can be heated to the same temperature in the chemical water pipeline 1, thereby effectively controlling the measurement error caused by temperature.

[0037] In some embodiments, the first temperature measuring device 3 and the second temperature measuring device 13 are both temperature sensors.

[0038] In some embodiments, the overflow hole 10 is disposed above the liquid inlet hole along the height direction of the sampling container 11. In the present disclosure, when the liquid level reaches the overflow hole 10, the excess liquid can flow out through the overflow hole 10, thereby maintaining a constant liquid level. This arrangement helps maintain the liquid level balance in the sampling container 11 and ensure a constant liquid flow rate.

[0039] In some embodiments, the sampling container 11 includes an outer tube, an inner tube and a tube cover 4, wherein the inner tube is arranged in the outer tube, and the tube cover 4 is detachably arranged at the tube mouth of the outer tube, wherein the heating device is arranged on the outer periphery of the inner tube.

[0040] In the present disclosure, a double-tube design of an inner tube and an outer tube is adopted, which can effectively keep the liquid in the inner tube warm. The tube cover 4 and the outer tube are detachable, which is convenient for operators to maintain, clean and replace the inner tube.

[0041] In some embodiments, the outer cylinder and the cylinder cover 4 are detachably connected by thread.

[0042] In some embodiments, the sampling device further includes a first control valve 9 , which is disposed on the sampling tube 2 , and is used to control the on-off of the chemical water sample in the sampling tube 2 .

[0043] In the present disclosure, the first control valve 9 is provided on the sampling tube 2 to effectively control the inflow and outflow of the chemical water sample. In addition, the first control valve 9 makes the use of the sampling device more flexible and controllable, and the flow of the chemical water sample can be shut off by the first control valve 9 during emergency shutdown or maintenance of the sampling device.

[0044] In some embodiments, the first control valve 9 is a manual primary gate valve.

[0045] In some embodiments, the sampling device also includes a second control valve 7 and a liquid guide tube 6, and the sampling container 11 is provided with a liquid outlet 12, wherein one end of the liquid guide tube 6 is connected to the liquid outlet 12, and the other end is connected to the conductivity measuring device, and the second control valve 7 is arranged on the liquid guide tube 6 for controlling the on and off of the chemical water sample in the liquid guide tube 6.

[0046] In some embodiments, the liquid guiding tube 6 is a stainless steel tube. The second control valve 7 is a manual one-way gate valve.

[0047] In the present disclosure, the second control valve 7 is provided on the liquid guide tube 6 to effectively control the inflow and outflow of the chemical water sample. In addition, the second control valve 7 makes the use of the sampling device more flexible and controllable, and the flow of the chemical water sample can be shut off by the second control valve 7 during emergency shutdown or maintenance of the sampling device.

[0048] In some embodiments, the sampling device further includes an overflow pipe 5 , one end of which is connected to the overflow hole 10 , and the overflow pipe 5 is used to conduct the chemical water sample overflowing from the overflow hole 10 .

[0049] In some embodiments, the overflow pipe 5 is a hose.

[0050] In some embodiments, the sampling device further comprises a heat preservation layer, which is arranged on the outer periphery of the outer cylinder. By providing the heat preservation layer, the heat preservation effect of the inner cylinder in the outer cylinder can be further enhanced to effectively control the measurement error caused by temperature.

[0051] A specific example provided by the present disclosure includes:

[0052] A sampling port is provided on the chemical water pipeline 1 and a sampling tube 2 is welded thereon, and a first temperature measuring device 3 and a first control valve 9 are provided on the sampling tube 2. The outlet of the sampling tube 2 is welded to the liquid inlet of the sampling container 11, and specifically, the liquid inlet is provided in the inner cylinder, and a through hole corresponding to the liquid inlet is provided on the outer cylinder, wherein the sampling tube 2 passes through the through hole and is connected to the liquid inlet.

[0053] The sampling container 11 includes an outer tube, an inner tube and a threaded tube cover 4. The inner tube is arranged in the outer tube, and the tube cover 4 is threadedly connected to the tube mouth of the outer tube. The sampling container 11 is provided with an overflow hole 10, specifically, the overflow hole 10 is opened in the inner tube, and a through hole corresponding to the overflow hole is arranged on the outer tube, wherein the overflow pipe 5 passes through the through hole and is connected to the overflow hole 10.

[0054] A liquid outlet 12 is provided at the bottom of the sampling container 11. Specifically, the liquid outlet 12 is opened in the inner tube, and a through hole corresponding to the liquid outlet 12 is provided on the outer tube, wherein the liquid guide tube 6 passes through the through hole and is connected to the liquid outlet 12. A second control valve 7 is provided on the liquid guide tube 6, and the outlet end of the liquid guide tube 6 is connected to a sampling hose 8, and the outlet end of the sampling hose 8 is connected to the conductivity measuring device.

[0055] The inner tube is made of stainless steel, and a heating device is wound around the outer part of the inner tube. The outermost layer of the outer tube is provided with a heat preservation layer, and the inner part is provided with a second temperature measuring device 13. The overflow hole 10 is consistent with the diameter of the overflow pipe 5, and the liquid outlet hole 12 is consistent with the diameter of the liquid guide pipe 6.

[0056] When the liquid level in the sampling container 11 is maintained at the overflow hole 10, the inner cylinder maintains a constant liquid level, and the bottom pressure remains unchanged, and the flow rate in the liquid guide tube 6 and the sampling hose 8 is constant. The first temperature measuring device 2 is connected to the DCS system, and the first measured temperature measured by the first temperature measuring device 2 is used as the temperature setting value of the PID controller. The second temperature measuring device 13 is connected to the DCS system, and the second measured temperature of the second temperature measuring device 13 is measured as the controlled quantity of the PID controller, wherein the PID controller controls the heating device according to the difference between the set value and the controlled quantity based on the PID controller to adjust the temperature of the chemical water sample in the sampling container. The PID controller adds a first-order inertia after the temperature input to ensure that the temperature in the sampling container 11 always follows the outlet temperature of the sampling tube to maintain consistency, thereby achieving the effect of temperature control and constant flow.

[0057] The sampling device disclosed in the present invention makes the liquid level in the sampling container constant and the outlet flow rate constant. In addition, through PID control, the problem of pH measurement fluctuation caused by the inconsistency between the temperature of the chemical water system and the measurement temperature is solved, the measurement accuracy is improved, and the water supply quality of the unit is guaranteed.

[0058] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A temperature-controlled constant-speed sampling device for chemical water in a power plant, characterized in that: include: A sampling container is provided with a liquid inlet and an overflow hole; A sampling tube, one end of which is connected to the liquid inlet hole and the other end of which is connected to the sampling port of the chemical water pipeline; A heating device, arranged in the sampling container; A first temperature measuring device is arranged at a position of the sampling tube close to the sampling port of the chemical water pipeline, and the first temperature measuring device is used to measure a first measurement temperature of the chemical water sample at the sampling port of the chemical water pipeline; A second temperature measuring device, disposed in the sampling container, for measuring a second measurement temperature of the chemical water sample in the sampling container; a PID controller, electrically connected to the first temperature measuring device, the second temperature measuring device and the heating device, respectively; The first measured temperature is used as a set value of the PID controller, the second measured temperature is used as a controlled variable of the PID controller, and the PID controller controls the heating device based on the difference between the set value and the controlled variable to adjust the temperature of the chemical water sample in the sampling container.

2. A temperature-controlled constant-speed sampling device for chemical water in a power plant according to claim 1, characterized in that: Along the height direction of the sampling container, the overflow hole is arranged above the liquid inlet hole.

3. A temperature-controlled constant-speed sampling device for chemical water in a power plant according to claim 1, characterized in that: The sampling container comprises an outer tube, an inner tube and a tube cover, wherein the inner tube is arranged in the outer tube, and the tube cover is detachably arranged at the tube opening of the outer tube; Wherein, the heating device is arranged on the outer periphery of the inner cylinder.

4. A temperature-controlled constant-speed sampling device for chemical water in a power plant according to claim 1, characterized in that: Also includes: The first control valve is arranged on the sampling tube, and the first control valve is used to control the on-off of the chemical water sample in the sampling tube.

5. A temperature-controlled constant-speed sampling device for chemical water in a power plant according to claim 1, characterized in that: Also includes: A second control valve and a liquid guide tube; the sampling container is provided with a liquid outlet; Among them, one end of the liquid guiding tube is connected to the liquid outlet, and the other end is connected to the conductivity measuring device; the second control valve is arranged on the liquid guiding tube, and is used to control the on-off of the chemical water sample in the liquid guiding tube.

6. A temperature-controlled constant-speed sampling device for chemical water in a power plant according to claim 1, characterized in that: Also includes: An overflow pipe has one end connected to the overflow hole, and the overflow pipe is used to conduct the chemical water sample overflowing from the overflow hole.

7. A temperature-controlled constant-speed sampling device for chemical water in a power plant according to claim 3, characterized in that: Also includes: The heat-insulating layer is arranged on the outer periphery of the outer cylinder.

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