Urea dissolving box heating device
By adopting a hydrophobic heating strip and a steam heating strip in the urea dissolution box heating device, high-temperature hydrophobic heating is preferred, which solves the problem of large amounts of steam consumed in the preparation of urea solution, and achieves energy conservation and reduction of wastewater treatment.
Patent Information
- Application Number
- CN202421840850.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-07-31
AI Technical Summary
A large amount of steam is consumed when preparing urea solution, resulting in waste of energy and failure to effectively utilize high-temperature hydrophobia, increasing the burden of wastewater treatment.
A urea dissolution box heating device is designed, and the hydrophobic heating strips and steam heating strips are arranged side by side. High-temperature hydrophobic heating is preferred. Steam heating is only used when there is no water in the hydrophobic tank.
Through hydrophobic circulation heating, about 1,300 tons of steam per year is saved, the chemical wastewater treatment volume is reduced by 1,300 tons, the wastewater system operation power consumption is reduced, and 9,000 kWh of electricity is saved annually.
Smart Images
Figure CN222841856U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of energy saving and emission reduction, and in particular to a urea dissolving box heating device. Background Art
[0002] At present, the country's requirements for environmental protection are becoming more and more stringent. In order to solve the problem of nitrogen oxide emissions meeting the standards, thermal power plants need to add denitrification equipment. The reducing agent of the denitrification device is ammonia, which can be directly produced by evaporation of liquid ammonia or hydrolysis of urea. However, due to the greater safety risks in the transportation and storage of liquid ammonia, thermal power plants that originally used liquid ammonia as a denitrification reducing agent have gradually changed to hydrolysis of urea to produce ammonia. Using high-temperature hydrophobic water as dissolving water, it takes about 2.2 tons of steam (factory steam with a pressure of 0.8MPa and a temperature of 200°C) to prepare one tank of urea solution (23 tons of dry urea, 50% concentration). If desalted water is used to prepare one tank of urea solution, 4.2 tons of steam are required. About 12,000 tons of steam are consumed per year, and the same amount of wastewater is added, which increases the power consumption and treatment burden of the wastewater system.
[0003] The drain tank has high-temperature drain from the urea hydrolyzer, dissolution tank, and solution tank. If it is not fully cooled and utilized, the temperature in the drain tank will be kept at about 100°C for a long time. This part of the drain heat cannot be effectively utilized, resulting in a large waste of heat and not conducive to resource conservation. In addition, the long-term high-temperature operation of the drain pump is prone to damage to the mechanical seal. Utility Model Content
[0004] The utility model aims to provide a urea dissolving box heating device to solve the technical problem of excessively high steam consumption in preparing urea solution.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A urea dissolution tank heating device comprises a steam heating circuit, a urea dissolution tank, and a drain tank connected in sequence, and also comprises a drain heating circuit, one end of which is connected to the urea dissolution tank, and the other end is connected to the drain tank. A coil heater is also arranged in the urea dissolution tank, one end of which is connected to the drain heating circuit, and the other end is connected to the drain tank.
[0007] The principle of this scheme is:
[0008] In actual application, the steam heating line is closed, the high-temperature drain in the drain tank is pumped out, and the high-temperature drain is transported to the urea dissolution tank through the drain heating line, and enters the coil heater evenly distributed in the urea dissolution tank. The heat of the high-temperature drain is dissipated into the urea dissolution tank to promote the full dissolution of urea, and the drain after heating flows into the drain tank; when there is no water in the drain tank, the steam heating line is enabled, the heating steam source is turned on, the heating steam enters the coil heater in the urea dissolution tank, and the drain after steam liquefaction enters the drain tank.
[0009] The advantages of this solution are:
[0010] 1. The existing technology mainly heats the urea dissolution tank by introducing high-temperature steam into the coil heater of the urea dissolution tank to increase the solution temperature and the amount of urea dissolved in the solution. However, the steam consumption is huge, which is not conducive to energy conservation. In addition, after the heating steam is liquefied, the urea hydrolyzer hydrolyzes the urea solution, and the high-temperature hydrophobicity generated by the urea solution storage tank also requires additional processing steps. There is a lack of effective utilization of the heat of the high-temperature hydrophobicity, and the long-term high temperature in the hydrophobic tank is not conducive to the operation of the equipment. Based on this, the utility model proposes a urea solution heating method in which the hydrophobic heating circuit and the steam heating circuit are parallel. In daily operation, high-temperature hydrophobicity is preferentially used for heating, and steam heating is only used when there is no water in the hydrophobic tank.
[0011] 2. This solution makes improvements on the original heating pipeline, basically without changing the system situation or the heating logic. It adopts the method of parallel drainage and steam heating pipelines, which is easy to operate and has strong reliability. It can reduce the operating temperature of the drain tank, improve the operating reliability of the drain pump, and significantly reduce the operation and maintenance costs of the drain pump.
[0012] 3. The use of drain circulation heating saves about 1,300 tons of steam per year; due to the reduction of system drain volume, the amount of chemical wastewater treatment is reduced by 1,300 tons; the power consumption of the wastewater system is reduced, saving 9,000 kWh of electricity per year.
[0013] Preferably, as an improvement, it further comprises an automatic drainage path and an automatic drainage device, wherein one end of the automatic drainage path is connected to the urea dissolution tank and the other end is connected to the drainage tank, and the automatic drainage device is installed on the automatic water delivery path. The automatic drainage device can identify steam and liquefied water. When steam is used as a heating source, the automatic drainage device will automatically drain the liquefied water after the steam dissipates heat and liquefies into water without the need for additional manual drainage.
[0014] Preferably, as an improvement, it further comprises a hydrophobic bypass, one end of the hydrophobic bypass is connected to the urea dissolution tank, and the other end is connected to the hydrophobic tank.
[0015] There is also a disadvantage in using steam to heat the urea dissolution tank. When the steam is heated and liquefied in the urea tank, the liquefied steam will be discharged through the automatic steam trap. However, in actual operation, the automatic steam trap is not absolutely accurate in identifying liquefied water and steam, and will mix steam with liquefied water and discharge it together, which not only causes a certain amount of steam waste, but also the mixing of steam and liquefied water will cause the problem of gas-liquid two-phase flow, causing vibration and noise in the equipment. This problem will not occur when using high-temperature steam traps because there is no steam. In addition, the automatic steam trap cannot be directly applied to the discharge of high-temperature steam traps after heating is completed, because the high-temperature steam trap is in liquid state, and the automatic steam trap will discharge the high-temperature steam trap that has not yet produced the heating effect. Therefore, a separate discharge waterway is required for the high-temperature steam trap. In response to this problem, this scheme adopts the setting of a steam trap bypass to realize the discharge of high-temperature steam traps, that is, a steam trap bypass is set up next to the automatic steam trap road, so that the high-temperature steam trap after heat dissipation enters the steam trap tank through the steam trap bypass without flowing through the automatic steam trap.
[0016] Preferably, as an improvement, it also includes a manual drain heating door, which is installed on the drain heating line. By opening the manual drain heating door, the high-temperature drain after heat dissipation is controlled to flow into the drain bypass and finally into the drain tank.
[0017] Preferably, as an improvement, it also includes a steam heating manual door, which is installed on the steam heating line. The steam heating manual door is used to control the heating steam to enter the steam heating line and the urea dissolving tank.
[0018] Preferably, as an improvement, the steam heating circuit and the drain heating circuit are connected to the urea dissolution tank via a steam heating automatic door. The steam heating automatic door can independently set the steam or high-temperature drain injection temperature. When the temperature in the dissolution tank is lower than the set temperature, the steam automatic heating door will automatically inject steam or high-temperature drain into the tank. When the temperature reaches the set temperature, it will automatically close and stop injecting steam or high-temperature drain.
[0019] Preferably, as an improvement, the automatic drain circuit further comprises a manual door in front of the steam trap and a manual door in rear of the steam trap, wherein the manual door in front of the steam trap is installed at the front end of the automatic steam trap, and the manual door in rear of the steam trap is installed at the rear end of the automatic steam trap. The manual door in front of the steam trap is used to control the steam liquefied water to enter the automatic steam trap, and the manual door in rear of the steam trap is used to control the liquefied water to enter the steam trap tank. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic structural diagram of an embodiment of the utility model. DETAILED DESCRIPTION
[0021] The following is further described in detail through specific implementation methods:
[0022] The figure marks in the drawings of the specification include: heating steam source 1, steam heating manual door 2, steam heating electric door 3, urea dissolution tank 4, coil heater 4-1, steam trap front manual door 5, automatic steam trap 6, steam trap rear manual door 7, steam trap heating manual door 8, steam trap bypass manual door 9, steam trap tank 10.
[0023] The embodiment is basically as shown in the attached Figure 1 As shown:
[0024] A urea dissolving tank heating device comprises a steam heating circuit, a drain heating circuit, a urea dissolving tank 4, and a drain tank 10 connected in sequence. There are two urea dissolving tanks 4, two steam heating circuits, and two drain heating circuits, all of which are distributed on the left and right. A coil heater 4-1 is arranged in the urea dissolving tank 4, and high-temperature drain or heating steam radiates heat to the solution in the urea dissolving tank 4 by flowing into the coil heater 4-1.
[0025] The upper ends of the steam heating line and the drain heating line on the left are connected to the heating steam source 1 and the drain tank 10 respectively, and the lower ends are connected to the steam heating electric door 3 and the urea dissolution tank 4. The drain heating line is equipped with a drain heating manual door 8 for controlling the high-temperature drain entering the pipeline. The steam heating line is equipped with a steam heating manual door 2 for controlling the heating steam entering the pipeline. The left end of the urea dissolution tank 4 is connected to an automatic drain line, and the automatic drain line is sequentially connected with a drain front manual door 5, an automatic drain 6, and a drain rear manual door 7 from left to right. The other end of the automatic drain line is connected to the drain tank 10. The drain tank 10 stores high-temperature drain from the urea hydrolyzer, the dissolution tank, and the solution storage tank. When it is not fully cooled and utilized, the temperature of the drain tank 10 is maintained at about 100°C for a long time. A drain bypass is also led out from the side of the automatic drain line. The drain bypass is provided with a drain bypass manual door 9, and the drain bypass is connected to the drain tank 10.
[0026] The relevant parts and their arrangement of the heating device on the right side are symmetrical to those on the left side.
[0027] In actual use, high-temperature hydrophobic water is preferentially used to heat the urea dissolving tank 4. The specific use process is: close the steam heating manual door 2 and hang a sign, turn on the water pump switch and the hydrophobic heating manual door 8 in the hydrophobic tank 10, so that the high-temperature hydrophobic water in the hydrophobic tank 10 can be pumped out, and the high-temperature hydrophobic water enters the coil heater 4-1 in the urea dissolving tank 4 through the hydrophobic heating line and the steam heating electric door 3. The heat of the high-temperature hydrophobic water is dissipated to the solution in the tank through the coil heater 4-1 to increase the solubility of urea in the solution.
[0028] At the same time, the manual door 9 of the drain bypass is opened to reduce the dynamic resistance, and the manual door 5 in front of the drain and the manual door 7 after the drain are closed to prevent the automatic drain 6 from automatically running and discharging the drain, which reduces the heating effect. At the same time, the logic of the steam heating electric door 3 remains unchanged. When the temperature in the urea dissolving tank 4 is lower than the set value, high-temperature drain is automatically added, and it is automatically closed when the temperature reaches the set temperature. The drain after the heat exchange is completed is introduced into the drain tank 10 through the drain bypass, and mixed with the high-temperature drain introduced into the drain tank 10 by the urea hydrolyzer and the solution storage tank for subsequent use.
[0029] When there is no water in the steam trap tank 10, turn off the steam trap pump switch, turn on the steam heating source and the steam heating manual door 2, keep the steam heating electric door 3 logic, inject steam into the coil heater 4-1 in the urea dissolution tank 4 through the steam heating line, dissipate heat to the solution, close the steam trap bypass manual door 9, open the steam trap front manual door 5 and the steam trap rear manual door 7, after the steam is liquefied, the automatic steam trap 6 will automatically export the liquefied water, and finally enter the steam trap 10 for subsequent use.
[0030] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.
Claims
1. A urea dissolving tank heating device, comprising a steam heating circuit, a urea dissolving tank, and a drain tank connected in sequence, characterized in that: It also includes a hydrophobic heating circuit, one end of which is connected to the urea dissolution tank, and the other end is connected to the hydrophobic tank. A coil heater is also provided in the urea dissolution tank, one end of the coil heater is connected to the hydrophobic heating circuit, and the other end is connected to the hydrophobic tank.
2. A urea dissolution tank heating device according to claim 1, characterized in that: It also includes an automatic drainage path and an automatic drain device. One end of the automatic drainage path is connected to the urea dissolution tank, and the other end is connected to the drain tank. The automatic drain device is installed on the automatic water delivery path.
3. A urea dissolution tank heating device according to claim 2, characterized in that: It also includes a hydrophobic bypass, one end of which is connected to the urea dissolution tank, and the other end of which is connected to the hydrophobic tank.
4. A urea dissolution tank heating device according to claim 3, characterized in that: It also includes a hydrophobic heating manual door, which is installed on the hydrophobic heating line.
5. The urea dissolution tank heating device according to claim 4, characterized in that: It also includes a steam heating manual door, which is installed on the steam heating line.
6. A urea dissolution tank heating device according to claim 5, characterized in that: The steam heating circuit and the drain heating circuit are connected to the urea dissolving tank through a steam heating automatic door.
7. The urea dissolution tank heating device according to claim 6, characterized in that: The automatic drain circuit also includes a front manual door of the drain trap and a rear manual door of the drain trap. The front manual door of the drain trap is installed at the front end of the automatic drain trap, and the rear manual door of the drain trap is installed at the rear end of the automatic drain trap.