Multi-mode heat tracing device for urea solution storage tank

Abstract

The utility model relates to the technical field of urea solution storage, and discloses a multimode heat tracing device for a urea solution storage tank, which comprises a urea solution storage tank, an electric heat tracing device is arranged in the urea solution storage tank, a heating coil for heating a urea solution is arranged in the urea solution storage tank, and the heating coil is connected with the electric heat tracing device. The top end and the bottom end of the heating coil pipe extend to the position above and below the urea solution storage tank correspondingly, rotating joints are arranged at the two ends of the heating coil pipe correspondingly, and a heat supply assembly is arranged on the urea solution storage tank. When the multimode heat tracing device of the urea solution storage tank is used, the system can flexibly select the most appropriate heating method according to available resources and environmental conditions, adaptability and economical efficiency of the device are improved, waste heat from a power plant is fully utilized, consumption of extra energy is reduced, and the policy of energy conservation and emission reduction is met.

Description

Technical Field

[0001] The utility model relates to the technical field of urea solution storage, in particular to a multi-mode heating device for a urea solution storage tank. Background Technique

[0002] As one of the essential reducing agents for the denitration system, urea is widely used due to its low cost, high safety, convenient transportation and storage, etc. Since urea as a denitration reducing agent needs to be prepared into a urea solution with a concentration of about 40-50%, and the crystallization temperature of a 40% concentration urea solution is about 2°C, and the crystallization temperature of a 50% concentration urea solution is about 18°C, when storing the urea solution, it is necessary to ensure that the temperature of the solution in the storage tank is always kept above the crystallization temperature, otherwise, the system pipeline will crystallize, affecting the system operation.

[0003] In the heating process of the urea solution storage tank, electric heating is the most mature and widely used technology. The working principle of the electric heating system is to generate heat through a resistance heating element, directly or indirectly heating the urea solution in the storage tank to maintain the solution within a preset temperature range and avoid urea crystallization. However, relying solely on the electric heating system to store the urea solution has the problem of a single means. The electric heating system completely depends on the power supply. In case of circuit failure, power shortage or power outage, the electric heating system will not be able to operate, resulting in the inability to effectively control the temperature of the urea solution, increasing the risk of urea crystallization. Urea crystallization will not only block pipelines and pumps, but also affect the urea injection system, leading to a reduction in denitration efficiency, an increase in nitrogen oxide emissions, and at the same time increasing the cleaning and maintenance costs. Moreover, the urea solution is a key component in the denitration system, and its unavailability will cause the interruption of the entire production process, affecting production efficiency and economic benefits.

[0004] Therefore, it is necessary to design a multi-mode heating device for a urea solution storage tank to solve the above problems. Content of the Utility Model

[0005] The purpose of the utility model is to solve the shortcomings existing in the prior art, and to propose a multi-mode heating device for a urea solution storage tank.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A multi-mode heating device for a urea solution storage tank, including a urea solution storage tank, an electric heating device is arranged inside the urea solution storage tank, a heating coil for heating the urea solution is arranged inside the urea solution storage tank, the top and bottom ends of the heating coil respectively extend above and below the urea solution storage tank, and rotary joints are arranged at both ends of the heating coil, and a heat supply component is arranged on the urea solution storage tank.

[0008] As a preferred technical solution of the present utility model, the heating assembly includes a connecting pipe, a hot water tracing element, a steam tracing element, and a drain tank;

[0009] Among them, the connecting pipe is arranged outside the urea solution storage tank, and the connecting pipe is communicated with a rotary joint located at the top end of the heating coil;

[0010] Among them, the hot water tracing element includes a hot water pipe, the hot water pipe is communicated with the connecting pipe, a hot water inlet stop valve is arranged on the hot water pipe, a water outlet pipe is arranged outside the urea solution storage tank, the water outlet pipe is communicated with a rotary joint located at the bottom end of the heating coil, a hot water outlet stop valve is arranged on the water outlet pipe, and the water outlet pipe is communicated with the drain tank;

[0011] Among them, the steam tracing element includes a steam pipe communicated with the connecting pipe, a steam inlet stop valve is arranged on the steam pipe, a water storage pipe is arranged outside the urea solution storage tank, the water storage pipe is communicated with a rotary joint located at the bottom end of the heating coil, the water storage pipe is also communicated with the inside of the drain tank, a steam outlet stop valve and a steam trap are arranged on the water storage pipe, and the steam trap is located on the side close to the drain tank.

[0012] As a preferred technical solution of the present utility model, manual stop valves are arranged on the hot water pipe, the steam pipe, the water outlet pipe, and the water storage pipe, and local pressure gauges are arranged on the hot water pipe and the steam pipe.

[0013] As a preferred technical solution of the present utility model, a temperature transmitter and a densitometer are arranged inside the urea solution storage tank.

[0014] As a preferred technical solution of the present utility model, a mixing assembly is further arranged on the urea solution storage tank. The mixing assembly includes a turbine arranged inside the connecting pipe. A rotating shaft is fixed at the bottom of the turbine. The bottom end of the rotating shaft penetrates through the inner bottom surface of the connecting pipe, and the rotating shaft is rotatably connected with the connecting pipe. The bottom end of the rotating shaft is rotatably connected with the top of the urea solution storage tank. The top end and the bottom end of the heating coil are coaxial with the urea solution storage tank, and the heating coil is rotatably connected with the urea solution storage tank. Gears are fixedly sleeved on the rotating shaft and the heating coil respectively, and the two gears are meshed with each other.

[0015] As a preferred technical solution of the present utility model, the part of the heating coil located inside the urea solution storage tank is in a serpentine structure, and the heating coil is made of copper material.

[0016] The present utility model has the following beneficial effects:

[0017] 1. Flexibility of multiple tracing methods: The choice between hot water tracing and steam tracing, combined with the backup option of electric tracing, enables the system to flexibly select the most suitable heating method based on available resources and environmental conditions. This makes the device applicable to different operating conditions, improving the adaptability and economy of the system. Especially when maintenance is required for the device, the design of multi-method tracing allows the device to operate without shutdown, ensuring the stability of the internal temperature of the urea solution storage tank.

[0018] 2. Energy conservation, emission reduction and resource utilization: By preferentially using hot water and steam, the waste heat from the power plant is fully utilized, reducing the consumption of additional energy, complying with the energy conservation and emission reduction policies, reducing operating costs, and at the same time reflecting the concept of green manufacturing.

[0019] 3. Uniform heating and anti-crystallization: The linkage design of the turbine and the heating coil not only realizes the efficient utilization of the heating medium, but also ensures the uniform distribution of heat by agitating the urea solution, effectively preventing crystallization and improving production efficiency and product quality. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a multi-method tracing device for a urea solution storage tank proposed by the present utility model;

[0021] Figure 2 It is a three-dimensional sectional view of the urea solution storage tank;

[0022] Figure 3 It is Figure 2 An enlarged view of the structure at A of

[0023] In the figure: 1 urea solution storage tank, 2 electric tracing device, 3 hot water pipe, 4 steam pipe, 5 connecting pipe, 6 heating coil, 7 outlet water pipe, 8 water storage pipe, 9 hot water inlet stop valve, 10 steam inlet stop valve, 11 drain tank, 12 manual stop valve, 13 hot water outlet stop valve, 14 steam outlet stop valve, 15 steam trap, 16 rotating shaft, 17 turbine, 18 gear, 19 rotary joint, 20 local pressure gauge, 21 temperature transmitter, 22 densitometer. Detailed Embodiments

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0025] Embodiment 1

[0026] Referring to Figure 1 and Figure 2, a multi-mode heat tracing device for urea solution storage tank, including a urea solution storage tank 1. Inside the urea solution storage tank 1, there are a temperature transmitter 21 and a densitometer 22. The densitometer 22 can monitor the density of the urea solution in real time, and the change in density can directly reflect the change in the urea content in the urea solution, which helps to adjust the production process in a timely manner to ensure that the solution meets the required specifications. The temperature transmitter 21 provides real-time temperature data, which is very important for controlling the physical properties of the urea solution because temperature affects the density, viscosity and chemical stability of the solution. In addition, the temperature data is also crucial for preventing urea crystallization. Inside the urea solution storage tank 1, there is an electric heat tracing device 2. Inside the urea solution storage tank 1, there is a heating coil 6 for heating the urea solution. The part of the heating coil 6 located inside the urea solution storage tank 1 is in a serpentine structure, which can increase the contact area between the heating coil 6 and the urea solution and can reduce the temperature difference between the top and bottom inside the storage tank, ensuring the heating effect of the device. And the heating coil 6 is made of copper material, which has good corrosion resistance and heat conduction performance. The top and bottom ends of the heating coil 6 extend above and below the urea solution storage tank 1 respectively, and rotary joints 19 are provided at both ends of the heating coil 6. A heat supply component is provided on the urea solution storage tank 1.

[0027] The heat supply component includes a connecting pipe 5, a hot water heat tracing part, a steam heat tracing part and a drain tank 11;

[0028] Among them, the connecting pipe 5 is arranged outside the urea solution storage tank 1, and the connecting pipe 5 is communicated with the rotary joint 19 located at the top end of the heating coil 6;

[0029] Among them, the hot water heat tracing part includes a hot water pipe 3. The hot water pipe 3 is communicated with the connecting pipe 5. A hot water inlet stop valve 9 is provided on the hot water pipe 3. An outlet water pipe 7 is arranged outside the urea solution storage tank 1. The outlet water pipe 7 is communicated with the rotary joint 19 located at the bottom end of the heating coil 6. A hot water outlet stop valve 13 is provided on the outlet water pipe 7. The outlet water pipe 7 is communicated with the drain tank 11;

[0030] Among them, the steam heat tracing part includes a steam pipe 4 communicated with the connecting pipe 5. A steam inlet stop valve 10 is provided on the steam pipe 4. A water storage pipe 8 is arranged outside the urea solution storage tank 1. The water storage pipe 8 is communicated with the rotary joint 19 located at the bottom end of the heating coil 6. The water storage pipe 8 is also communicated with the inside of the drain tank 11. A steam outlet stop valve 14 and a steam trap 15 are provided on the water storage pipe 8, and the steam trap 15 is located on the side close to the drain tank 11;

[0031] Manual stop valves 12 are provided on the hot water pipe 3, steam pipe 4, outlet pipe 7 and storage pipe 8. Specifically, the manual stop valve 12 on the hot water pipe 3 is located between the hot water inlet port and the hot water inlet stop valve 9. The manual stop valve 12 on the steam pipe 4 is located between the steam inlet end and the steam inlet stop valve 10. Two manual stop valves 12 are provided on the outlet pipe 7 and are respectively located at both ends of the hot water outlet stop valve 13. Two manual stop valves 12 are also provided on the storage pipe 8, and the steam outlet stop valve 14 and the hot steam trap 15 are located between the two manual stop valves 12. The manual stop valve 12 can cut off the fluid or gas supply of the tracing system when necessary, such as during maintenance, repair or replacement of equipment, or in case of emergencies such as system leakage or overpressure, to ensure the safety of operators and prevent the expansion of accidents. By closing the stop valve near the affected area, a part of the tracing system can be maintained or replaced without stopping the operation of the entire system, reducing the production interruption time and cost. Local pressure gauges 20 are provided on both the hot water pipe 3 and the steam pipe 4. The local pressure gauges 20 can provide immediate pressure readings, allowing the operator to check the pressure status of the tracing medium in the pipeline at any time, which is crucial for ensuring the normal operation of the tracing system.

[0032] Working principle: The density meter 22 and temperature transmitter 21 on the side wall of the storage tank feedback the density and temperature parameters of the urea solution to the DCS system to determine whether to activate the tracing system and select the appropriate tracing method, so as to keep the solution temperature always above the crystallization temperature of 10°C. When hot water is selected as the heating medium, the hot water inlet stop valve 9 and the hot water outlet stop valve 13 are opened. The hot water in the power plant enters the hot water pipe 3 and then enters the heating coil 6 through the connecting pipe 5, thereby controlling the temperature of the urea storage solution. Subsequently, the hot water enters the drain tank 11 through the outlet pipe 7 for collection and storage. When hot steam is selected as the heating medium, the steam inlet stop valve 10 and the steam outlet stop valve 14 are opened. The steam enters the connecting pipe 5 through the steam pipe 4 and then enters the storage pipe 8. Since the hot steam trap 15 is provided on the coil outlet pipe, and the hot steam trap 15 has the function of blocking steam and draining water, it can evenly heat the steam heating equipment, make full use of the latent heat of steam, and the discharged hot water enters the drain tank 11. When there is no surplus of hot steam and hot water in the power plant, the standby electric tracing device 2 can be activated. This device makes full use of the waste heat energy of the power plant, increases the tracing means for urea solution storage, reduces the operation cost of the power plant, responds to the national energy conservation and emission reduction policy, and ensures the stable operation of the system.

[0033] Embodiment 2

[0034] Embodiment 2 includes the content of Embodiment 1. The technical features disclosed in Embodiment 1 are also applicable to this embodiment. The technical features already disclosed in Embodiment 1 will not be repeatedly described in the specification. The following will further elaborate on the implementation manner of the multi-mode heat tracing device for urea solution storage tank in conjunction with the accompanying drawings.

[0035] Referring to Figure 2 and Figure 3 , a mixing component is further provided on the urea solution storage tank 1. The mixing component includes a turbine 17 disposed inside the connecting pipe 5. The connecting pipe 5 is made of a rigid heat-insulating composite material and has a fixed position. A rotating shaft 16 is fixed to the bottom of the turbine 17. The bottom end of the rotating shaft 16 penetrates the inner bottom surface of the connecting pipe 5, and the rotating shaft 16 is rotatably connected to the connecting pipe 5. The bottom end of the rotating shaft 16 is rotatably connected to the top of the urea solution storage tank 1. The top and bottom ends of the heating coil 6 are coaxial with the urea solution storage tank 1, and the heating coil 6 is rotatably connected to the urea solution storage tank 1. Gear sleeves 18 are fixedly sleeved on both the rotating shaft 16 and the heating coil 6, and the two gear sleeves 18 are meshed with each other.

[0036] Working principle: When using the hot water heat tracing component or the steam heat tracing component to perform heat preservation operation on the urea solution, the hot water or steam fluid is passed into the connecting pipe 5 after high-pressure treatment and passes through the turbine 17. The high-speed flowing fluid can drive the turbine 17 to rotate and drive the rotating shaft 16 to rotate. Under the transmission action of the gear 18, the heating coil 6 can rotate. In this way, the heating coil 6 can stir the urea solution, enabling the heat to be evenly transferred, and thus effectively preventing the crystallization of the urea solution.

[0037] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and the inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A multi-mode heating device for a urea solution storage tank, comprising a urea solution storage tank (1), characterized in that: The urea solution storage tank (1) is provided with an electric heating device (2) inside, and a heating coil (6) for heating the urea solution is provided inside the urea solution storage tank (1), the top and bottom ends of the heating coil (6) respectively extend to the top and bottom of the urea solution storage tank (1), and both ends of the heating coil (6) are provided with rotating joints (19), and the urea solution storage tank (1) is provided with a heating component.

2. The multi-mode heating device for a urea solution storage tank according to claim 1, characterized in that: The heating assembly comprises a connecting pipe (5), a hot water heating component, a steam heating component and a drain tank (11); The connecting pipe (5) is arranged outside the urea solution storage tank (1), and the connecting pipe (5) is connected to a rotary joint (19) located at the top end of the heating coil (6); The hot water heating component comprises a hot water pipe (3), the hot water pipe (3) is connected to a connecting pipe (5), a hot water inlet stop valve (9) is provided on the hot water pipe (3), a water outlet pipe (7) is provided outside the urea solution storage tank (1), the water outlet pipe (7) is connected to a rotary joint (19) located at the bottom end of the heating coil (6), a hot water outlet stop valve (13) is provided on the water outlet pipe (7), and the water outlet pipe (7) is connected to a drain tank (11); The steam tracing component comprises a steam pipe (4) connected to the connecting pipe (5), a steam inlet stop valve (10) being provided on the steam pipe (4), a water storage pipe (8) being provided outside the urea solution storage tank (1), the water storage pipe (8) being connected to a rotary joint (19) located at the bottom end of the heating coil (6), the water storage pipe (8) being also connected to the inside of a drain tank (11), a steam outlet stop valve (14) and a hot steam drain valve (15) being provided on the water storage pipe (8), and the hot steam drain valve (15) being located on a side close to the drain tank (11).

3. The multi-mode heating device for a urea solution storage tank according to claim 2, characterized in that: The hot water pipe (3), the steam pipe (4), the water outlet pipe (7) and the water storage pipe (8) are all provided with manual stop valves (12), and the hot water pipe (3) and the steam pipe (4) are all provided with local pressure gauges (20).

4. The multi-mode heating device for a urea solution storage tank according to claim 1, characterized in that: A temperature transmitter (21) and a density meter (22) are provided inside the urea solution storage tank (1).

5. The multi-mode heating device for a urea solution storage tank according to claim 2, characterized in that: The urea solution storage tank (1) is also provided with a mixing assembly, the mixing assembly comprising a turbine (17) arranged inside the connecting pipe (5), a rotating shaft (16) being fixed at the bottom of the turbine (17), the bottom end of the rotating shaft (16) penetrating the inner bottom surface of the connecting pipe (5), the rotating shaft (16) being rotatably connected to the connecting pipe (5), the bottom end of the rotating shaft (16) being rotatably connected to the top of the urea solution storage tank (1), the top and bottom ends of the heating coil (6) being coaxial with the urea solution storage tank (1), the heating coil (6) being rotatably connected to the urea solution storage tank (1), the rotating shaft (16) and the heating coil (6) being fixedly sleeved with gears (18), the two gears (18) being meshed with each other.

6. The multi-mode heating device for a urea solution storage tank according to claim 5, characterized in that: The portion of the heating coil (6) located inside the urea solution storage tank (1) has a serpentine structure, and the heating coil (6) is made of copper material.

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