Urea pipeline thermal insulation system for thermal power plant

Abstract

The utility model relates to a urea pipeline heat preservation system for a thermal power plant. The urea pipeline heat preservation system comprises a conveying pipeline. The heating mechanism is arranged on the periphery of the conveying pipeline, and the heating power of the heating mechanism is adjustable; the monitoring mechanism is configured to be capable of measuring the temperature and flow of urea in the conveying pipeline; the controller is in signal connection with the heating mechanism and the monitoring mechanism, and the controller is configured to control the heating power of the heating mechanism to heat the urea in the conveying pipeline according to the temperature and flow data obtained by the monitoring mechanism. Therefore, the controller can control the heating mechanism to heat the conveying pipeline at the adaptive power according to the temperature and flow data obtained by the monitoring mechanism, the urea temperature can be adjusted in real time, pipeline crystallization and corrosion caused by too low urea temperature are avoided, and the safety and stability of urea conveying are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of urea pipeline heating in a thermal power plant, and in particular to a urea pipeline insulation system for a thermal power plant. Background Art

[0002] The existing segmented steam pipeline tracing pre-buried insulation system uses the auxiliary steam of the thermal power plant as the heat source to heat the long-distance urea main pipe in sections. Each section of the tracing pipeline uses steam to release heat through the steam tracing pipeline parallel to the urea main pipe, thereby achieving the purpose of ensuring the temperature of the urea main pipe. The design of a single heating pipeline parallel to the urea main pipe makes the insulation effect of the urea main pipe poor. At the same time, the steam tracing insulation system does not have an automatic adjustment function, and has low adaptability to sudden drops in ambient temperature and changes in load conditions. It requires manual intervention to adjust the valve opening of each section of steam inlet. The entire adjustment process has many operations and a long control lag. The main pipe temperature often runs below the specified range. Too low a temperature of the urea main pipe will lead to pipeline crystallization, corrosion, nozzle blockage and other severe conditions, bringing safety hazards to thermal power plants. Utility Model Content

[0003] The purpose of the present disclosure is to provide a urea pipeline insulation system for a thermal power plant, which can adjust the heating temperature of the urea pipeline in real time to at least partially solve the problems in the related art.

[0004] In order to achieve the above-mentioned purpose, the present disclosure provides a urea pipeline insulation system for a thermal power plant, comprising a delivery pipeline; a heating mechanism, which is arranged on the outer periphery of the delivery pipeline and is configured to have adjustable heating power; a monitoring mechanism, which is configured to be able to measure the urea temperature and flow rate in the delivery pipeline; and a controller, which is signal-connected to the heating mechanism and the monitoring mechanism respectively, and is configured to be able to control the heating power of the heating mechanism to heat the urea in the delivery pipeline according to the temperature and flow rate data obtained by the monitoring mechanism.

[0005] Optionally, the heating mechanism comprises at least two heating wires, and adjacent heating wires are independently arranged and spirally wound around the outer circumference of the conveying pipe.

[0006] Optionally, the heating mechanism further includes a thyristor voltage regulator, which is connected to the controller and the heating wire respectively, and is used to adjust the voltage of the heating wire.

[0007] Optionally, there are multiple thyristor voltage regulators and they are arranged in one-to-one correspondence with the heating wires.

[0008] Optionally, the monitoring mechanism includes a thermometer and a flow meter, and the thermometer and the flow meter are arranged at intervals along the conveying direction of the conveying pipeline, and the thermometer and the flow meter are connected to the controller signal.

[0009] Optionally, there are two thermometers, and both thermometers are located at the outlet of the delivery pipeline.

[0010] Optionally, the urea pipeline insulation system further includes an insulation layer, the insulation layer is sleeved on the outer circumference of the delivery pipeline, and the heating wire is arranged in the insulation layer.

[0011] Optionally, the urea pipeline insulation system further includes an insulation layer, and the insulation layer is arranged on the outer periphery of the insulation layer.

[0012] Optionally, the heating mechanism further includes a positioning buckle, and there are multiple positioning buckles, and the multiple positioning buckles are fixed in the insulation layer and used to fix the heating wire.

[0013] Optionally, the positioning buckle is provided with a tapered installation groove, and an anti-wear pad is provided in the installation groove.

[0014] Through the above technical scheme, the urea in the delivery pipeline can be heated with variable power through the heating mechanism, the urea temperature and flow rate in the delivery pipeline can be obtained through the monitoring mechanism, and the controller is connected with the heating mechanism and the monitoring mechanism by signal, so that the controller can control the heating mechanism to heat the delivery pipeline with an adaptive power according to the temperature and flow rate data obtained by the monitoring mechanism, so that the urea temperature can be adjusted in real time, avoiding crystallization and corrosion of the pipeline caused by too low urea temperature, and improving the safety and stability of urea transportation.

[0015] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0017] Figure 1 is a structural schematic diagram of a urea pipeline insulation system for a thermal power plant provided in an exemplary embodiment of the present disclosure;

[0018] Figure 2 It is a schematic diagram of the structure of a positioning buckle provided in an exemplary embodiment of the present disclosure.

[0019] Description of Reference Numerals

[0020] 1-transport pipeline; 2-heating mechanism; 21-heating wire; 22-thyristor voltage regulator; 23-positioning buckle; 231-installation slot; 232-anti-wear pad; 3-monitoring mechanism; 31-thermometer; 32-flow meter. DETAILED DESCRIPTION

[0021] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0022] In this disclosure, unless otherwise stated, directional words such as "inside" and "outside" refer to the outline of the component itself. In addition, the terms "first", "second", etc. used in this disclosure are to distinguish one element from another element and do not have order or importance. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0023] In the related art, the auxiliary steam of the existing thermal power plant is used as a heat source to heat the long-distance urea main pipe in sections. Each section of the tracing pipeline uses steam to release heat through the steam tracing pipeline parallel to the urea main pipe, so as to achieve the purpose of ensuring the temperature of the urea main pipe. The design of a single heating pipeline parallel to the urea main pipe makes the insulation effect of the urea main pipe poor. At the same time, the steam tracing and insulation system does not have an automatic adjustment function, and has low adaptability to sudden drops in ambient temperature and changes in load conditions. It is necessary to manually intervene in the valve opening of each section of the steam inlet to adjust the adjustment. The entire adjustment process has many operations and a long control lag. The main pipe temperature often runs below the specified range. Too low a temperature of the urea main pipe will cause problems such as pipeline crystallization, corrosion, and nozzle blockage.

[0024] In order to solve the above technical problems, Figure 1-Figure 2 As shown, the present disclosure provides a urea pipeline insulation system for a thermal power plant, comprising a conveying pipeline 1, a heating mechanism 2, a monitoring mechanism 3 and a controller; wherein the conveying pipeline 1 is arranged between a urea hydrolysis workshop and a boiler, and the conveying pipeline 1 is used to convey urea from the urea hydrolysis workshop to the boiler, the heating mechanism 2 is arranged on the outer periphery of the conveying pipeline 1, and the heating mechanism 2 is configured to heat the urea in the conveying pipeline 1 with adjustable heating power; the monitoring mechanism 3 is configured to be able to obtain the urea temperature and flow rate in the conveying pipeline 1; the controller is respectively connected to the heating mechanism 2 and the monitoring mechanism 3 by signal, and the controller is configured to be able to control the heating mechanism 2 to heat the urea in the conveying pipeline 1 according to the temperature and flow rate data obtained by the monitoring mechanism 3.

[0025] Through the above technical scheme, the urea in the delivery pipeline 1 can be heated with variable power by the heating mechanism 2, the urea temperature and flow rate in the delivery pipeline can be obtained by the monitoring mechanism 3, and the controller is connected with the heating mechanism 2 and the monitoring mechanism 3 by signal, so that the controller can control the heating mechanism 2 to heat the delivery pipeline with an adaptive power according to the temperature and flow rate data obtained by the monitoring mechanism 3, so that the urea temperature can be adjusted in real time, avoiding crystallization and corrosion of the pipeline caused by too low urea temperature, and improving the safety and stability of urea transportation.

[0026] In order to facilitate heating of urea in the delivery pipeline 1, in some practicable embodiments, the heating mechanism 2 includes at least two heating wires 21, and adjacent heating wires 21 are independently arranged and spirally wound around the outer periphery of the delivery pipeline 1. For example, the heating mechanism 2 has three heating wires 21, and the heating wires 21 are electrically connected to an external power source, wherein the external power source may be a battery or power grid, and the three heating wires 21 are independently arranged and spirally wound around the delivery pipeline 1 without interfering with each other, so that one, two or three heating wires 21 can be selectively selected to heat the delivery pipeline 1 according to the urea flow and temperature in the delivery pipeline 1, so that the urea temperature can be adjusted in real time, and the crystallization and corrosion of the pipeline caused by too low urea temperature can be avoided, thereby improving the safety and stability of urea delivery.

[0027] Of course, it is understandable that the number of the above-mentioned heating wires 21 is schematic. In other embodiments, the number of heating wires 21 can also be set according to specific working conditions. For example, the number of heating wires 21 can also be four, five, etc., which is not limited in the present disclosure.

[0028] In order to facilitate the adjustment of the heating power of the heating wire 21 to heat the urea in the delivery pipeline 1, in some feasible embodiments, the heating mechanism 2 also includes a thyristor voltage regulator 22, which is respectively connected to the controller and the heating wire 21, and the thyristor voltage regulator 22 is used to adjust the voltage of the heating wire 21, thereby adjusting the heating power of the heating wire 21. For example, the thyristor voltage regulator 22 may include a first voltage regulating circuit and a second voltage regulating circuit, wherein the first voltage regulating circuit and the second voltage regulating circuit are first connected in parallel and then in series with the heating line 21, a fixed resistor is provided on the first voltage regulating circuit, and a sliding rheostat connected in series with the fixed resistor and a capacitor connected in series with the fixed resistor are respectively provided upstream and downstream of the fixed resistor, a bidirectional thyristor is provided on the second voltage regulating circuit, an auxiliary voltage regulating line is provided between the fixed resistor and the capacitor, the auxiliary voltage regulating line is used to connect the bidirectional thyristor, and a bidirectional diode is provided on the auxiliary voltage regulating line. When working, after the capacitor is charged, the potential at the auxiliary voltage regulating line reaches the gate line voltage of the bidirectional diode, and the bidirectional diode is turned on, so that the bidirectional thyristor receives a control signal to turn on, so that the heating line 21 starts to work, and the conduction time of the trigger circuit composed of the capacitor, the bidirectional diode and the bidirectional thyristor is controlled by adjusting the resistance value of the sliding rheostat, thereby controlling the average voltage within a unit cycle, thereby adjusting the heating power of the heating line 21, thereby heating the urea in the conveying pipeline 1. It can be understood that the heating power of the heating wire 21 can be steplessly adjusted by the sliding rheostat, so that it can adapt to the requirements of various temperature conditions and has good versatility. In addition, the thyristor voltage regulator 22 is an existing device and can be purchased by yourself, and its specific structure will not be described in detail in this disclosure.

[0029] In order to facilitate the heating power adjustment of different heating wires 21, in some feasible methods, the number of thyristor voltage regulators 22 is one, and multiple heating wires 21 are connected to the thyristor voltage regulator 22, so that the power of multiple heating wires 21 can be adjusted simultaneously through one thyristor voltage regulator 22, thereby being able to adapt to the requirements of different heating temperatures.

[0030] Of course, there are multiple thyristor voltage regulators 22 and the multiple thyristor voltage regulators 22 are arranged in a one-to-one correspondence with the heating wires 21. For example, there can be three heating wires 21, and each heating wire 21 is configured with a corresponding thyristor voltage regulator 22. In this way, the heating power of each heating wire 21 can be controlled more accurately, thereby heating the urea in the delivery pipeline 1.

[0031] In order to facilitate the heating of urea in the delivery pipeline 1, in some feasible embodiments, the monitoring mechanism 3 includes a thermometer 31 and a flowmeter 32, and the thermometer 31 and the flowmeter 32 are arranged at intervals along the delivery direction of the delivery pipeline 1, and the thermometer 31 and the flowmeter 32 are both connected to the controller signal, wherein the thermometer 31 and the flowmeter 32 are respectively arranged on the delivery pipeline 1, the thermometer 31 is used to monitor the urea temperature in the delivery pipeline 1, and the flowmeter 32 is used to monitor the urea flow in the delivery pipeline 1, and the thermometer 31 and the flowmeter 32 are both connected to the controller signal, wherein the thermometer 31 and the flowmeter 32 can be connected to the controller signal by wire or by wireless, and the wireless method can be a transmission method such as WIFI, 4G, 5G or Bluetooth, and the controller controls the number of corresponding heating wires 21 turned on and the heating power corresponding to each heating wire 21 according to the data obtained by the thermometer 31 and the flowmeter 32, so that the temperature of the urea in the delivery pipeline 1 can be controlled in real time, so that the urea temperature in the delivery pipeline 1 is within a preset temperature range.

[0032] In some practicable ways, the number of thermometers 31 and flowmeters 32 are both multiple, at least one thermometer 31 is located at the outlet of the delivery pipeline 1, and at least one flowmeter 32 is at the entrance of the delivery pipeline 1. The setting of multiple thermometers 31 can obtain the temperature data of urea at multiple sections of urea in the delivery pipeline 1. Multiple thermometers 31 can work at the same time. Multiple thermometers 31 can obtain multiple samples when working at the same time, which improves the accuracy of urea temperature measurement. It can also be part of the work, and the other part of the thermometer 31 is used as a spare part. When the thermometer 31 fails during use, it can be opened by another part of the thermometer 31 to avoid shutdown and maintenance; multiple flowmeters 32 can work at the same time, or part of the work. Multiple flowmeters 32 work at the same time, which can be mutually checked and verified, and improve the accuracy of urea flow measurement in the delivery pipeline 1. Of course, the flowmeter 32 can also be part of the work, and the other part is used as a spare part. It should be noted that the above-mentioned thermometers 31 and flowmeters 32 are both existing products, which can be purchased and obtained, and the present disclosure will not repeat their specific structures.

[0033] In order to further insulate the urea in the conveying pipeline 1, in some feasible embodiments, the urea pipeline insulation system also includes an insulation layer (not shown in the figure), the insulation layer is sleeved on the outer periphery of the conveying pipeline, and the heating wire 21 is arranged in the insulation layer. The insulation layer can be set as insulation cotton, and the insulation cotton can be divided into multiple layers and wound around the outer periphery of the conveying pipeline 1, wherein the heating wire 21 is arranged between the innermost layer and the second inner layer of insulation cotton, so that the urea in the conveying pipeline 1 can be heated by the heating wire 21 and the heat exchange between the conveying pipeline 1 and the external ambient temperature can be avoided.

[0034] In some feasible embodiments, the urea pipeline insulation system also includes an insulating layer (not shown in the figure), which may be a polyimide film. The insulating layer is arranged on the periphery of the insulation layer and is coated on the outside of the insulation layer. Thus, once the heating wire 21 leaks electricity, it can be blocked by the insulating layer to improve safety.

[0035] In order to facilitate winding the heating wire 21 into the thermal insulation cotton on the outer periphery of the conveying pipe 1, in some feasible embodiments, the heating mechanism 2 also includes a positioning buckle 23, and there are multiple positioning buckles 23. Multiple positioning buckles 23 are fixed in the thermal insulation layer and used to fix the heating wire 21. The bottom ends of the multiple positioning buckles 23 are inserted into the thermal insulation cotton through long nail columns, and the top of the positioning buckle 23 is provided with a tapered installation groove 231. The cross-section of the installation groove 231 can be a triangular prism groove. The installation groove 231 is used to position the heating wire 21, so that through the arrangement of multiple positioning buckles 23, the heating wire 21 can be conveniently wound into the thermal insulation cotton on the outer periphery of the conveying pipe 1.

[0036] In addition, in order to prevent the heating wire 21 and the mounting groove 231 from being worn, an anti-wear pad 232 is provided in the mounting groove 231. The anti-wear pad 232 can be fixed on the inner wall of the mounting groove 231. The anti-wear pad 232 can be made of PVC. Through the setting of the anti-wear pad 232, friction between the heating wire 21 and the mounting groove 231 can be prevented, which may cause damage to the mounting groove 231.

[0037] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0038] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0039] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A urea pipeline insulation system for a thermal power plant, characterized in that: include Transportation pipelines; A heating mechanism, the heating mechanism is disposed on the outer periphery of the delivery pipeline, and the heating mechanism is configured to heat the urea in the delivery pipeline with adjustable heating power; A monitoring mechanism, wherein the monitoring mechanism is configured to obtain the temperature and flow rate of urea in the delivery pipeline; and A controller is respectively connected to the heating mechanism and the monitoring mechanism by signals, and the controller is configured to control the heating mechanism to heat the urea in the delivery pipeline according to the temperature and flow data acquired by the monitoring mechanism.

2. The urea pipeline insulation system for a thermal power plant according to claim 1, characterized in that: The heating mechanism comprises at least two heating wires, and the adjacent heating wires are independently arranged and spirally wound around the outer circumference of the conveying pipe.

3. The urea pipeline insulation system for a thermal power plant according to claim 2, characterized in that: The heating mechanism further comprises a thyristor voltage regulator, which is connected to the controller and the heating wire respectively, and is used for adjusting the voltage of the heating wire.

4. The urea pipeline insulation system for a thermal power plant according to claim 3, characterized in that: The number of the thyristor voltage regulator is one, and the plurality of heating wires are all connected to the thyristor voltage regulator; or The number of the thyristor voltage regulators is multiple and the multiple thyristor voltage regulators are arranged in one-to-one correspondence with the heating wires.

5. The urea pipeline insulation system for a thermal power plant according to any one of claims 1 to 4, characterized in that: The monitoring mechanism comprises a thermometer and a flowmeter, and the thermometer and the flowmeter are arranged at intervals along the conveying direction of the conveying pipeline, and the thermometer and the flowmeter are connected to the controller signal.

6. The urea pipeline insulation system for a thermal power plant according to claim 5, characterized in that: There are multiple thermometers and flowmeters, at least one thermometer is located at the outlet of the delivery pipeline, and at least one flowmeter is located at the inlet of the delivery pipeline.

7. The urea pipeline insulation system for a thermal power plant according to claim 2, characterized in that: The urea pipeline insulation system further comprises an insulation layer, wherein the insulation layer is sleeved on the outer circumference of the delivery pipeline, and the heating wire is arranged in the insulation layer.

8. The urea pipeline insulation system for a thermal power plant according to claim 7, characterized in that: The urea pipeline insulation system further comprises an insulation layer, and the insulation layer is arranged on the outer periphery of the insulation layer.

9. The urea pipeline insulation system for a thermal power plant according to claim 7, characterized in that: The heating mechanism also includes a positioning buckle, and there are multiple positioning buckles. The multiple positioning buckles are fixed in the insulation layer and are used to fix the heating wire.

10. The urea pipeline insulation system for a thermal power plant according to claim 9, characterized in that: The positioning buckle is provided with a shrinking installation groove, and an anti-wear pad is arranged in the installation groove.

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