Novel urea hydrolyzer

Abstract

The utility model relates to a novel urea hydrolyzer, which comprises a hydrolyzer main body, and further comprises a saturated steam inlet component, a saturated steam outlet component, a saturated steam outlet component and a saturated steam outlet component, the urea solution inlet assembly is communicated with the hydrolyzer main body and is used for introducing a urea solution; the hydrophobic component is communicated with the hydrolyzer main body and is used for discharging hydrophobic water; the electric heating unit is arranged in the hydrolyzer main body and is used for heating when the auxiliary steam pressure is insufficient; the coil pipe type steam heating device is used for heating when the auxiliary steam pressure is sufficient; and the DCS system is connected with the electric heating unit and is used for automatically controlling the input power of the electric heating unit according to the real-time electricity price. The utility model has the advantages that: 1, the condition that the hydrolyzer cannot perform normal hydrolysis to generate product gas when the auxiliary steam supply is insufficient is avoided; 2, electric heating is input in low-electricity-price and negative-electricity-price periods, so that the on-grid electricity quantity is reduced, and the electricity charge loss is reduced;

Description

Technical Field

[0001] This utility model relates to a novel urea hydrolyzer, belonging to the field of power plant chemical systems. Background Technology

[0002] To reduce the safety risks associated with the transportation and storage of liquid ammonia, power plants are switching their SCR denitrification reducing agent from liquid ammonia to urea. There are two main mature methods for producing ammonia from urea: pyrolysis and hydrolysis. Because urea hydrolysis has a lower heating decomposition temperature, allows for the recycling of demineralized water, and consumes less energy than pyrolysis, it is gradually becoming the preferred option for power plants. The heating steam in the hydrolyzer typically comes from the plant's auxiliary steam, requiring a pressure of at least 0.7 MPa and a temperature of at least 300°C. The depressurized and de-cooled saturated steam enters the hydrolyzer through coils. This saturated steam does not mix with the urea solution but instead flows back through the coils. When the pressure and temperature of the auxiliary steam are below the required values, the hydrolyzer will be unable to perform the hydrolysis reaction normally to produce product gas.

[0003] With changes in market operations, frequent start-ups and shutdowns of coal-fired power units have become the norm. During periods of high renewable energy generation, power plants often operate with only one unit running, and during off-peak periods, units reduce their technical output to minimum, leading to insufficient auxiliary steam supply. Insufficient auxiliary steam pressure primarily affects the safe operation of the main equipment. To prioritize the protection of the main equipment, other auxiliary steam users are reduced to improve the safety of main equipment operation. Furthermore, the market operates on a time-of-use pricing policy; the less electricity generated during low-price periods, the less loss for the enterprise. When auxiliary steam pressure is insufficient, unit load is low, and electricity prices are often low, even potentially negative. In such situations, reducing steam consumption by on-site users and implementing electricity substitution measures can reduce power generation losses during negative-price periods.

[0004] For example, during holidays, the social electricity load is low, the power generation of new energy sources is high, and only a few units of the power plant are maintained in operation. The period of negative electricity price is long, and the auxiliary steam pressure is lower than 0.4MPa, which cannot meet the normal operating requirements of the hydrolyzer. Utility Model Content

[0005] To overcome the shortcomings of existing technologies, this utility model provides a novel urea hydrolyzer. The technical solution of this utility model is as follows:

[0006] A novel urea hydrolyzer includes a hydrolyzer body and further includes:

[0007] The saturated steam inlet assembly is connected to the main body of the hydrolyzer and is used to introduce saturated steam.

[0008] The urea solution inlet assembly is connected to the main body of the hydrolyzer and is used to introduce urea solution.

[0009] A hydrophobic component, connected to the main body of the hydrolyzer, is used to discharge hydrophobic material;

[0010] An electric heating unit, located inside the hydrolyzer body, is used to provide heating when the auxiliary steam pressure is insufficient; a coil-type steam heating device is used to provide heating when the auxiliary steam pressure is sufficient.

[0011] The DCS system is connected to the electric heating unit and is used to automatically control the power of the electric heating unit based on the real-time electricity price.

[0012] The saturated steam intake assembly includes a saturated steam intake pipe. One end of the saturated steam intake pipe is connected to a saturated steam source, and the other end is connected to the steam inlet of the hydrolyzer body. On the saturated steam intake pipe, a manual valve before steam intake, a pneumatic valve for steam intake, and a manual valve after steam intake are installed sequentially along the flow direction of the saturated steam.

[0013] The urea solution inlet assembly includes a main urea solution inlet pipe, one end of which forms a urea solution inlet, and the other end which connects to the solution inlet of the hydrolyzer body. A urea solution inlet manual valve, a urea solution inlet pneumatic regulating valve, and another urea solution inlet manual valve are sequentially installed on the main urea solution inlet pipe between the urea solution inlet and the solution inlet of the hydrolyzer body. The assembly also includes a urea solution inlet branch pipe, one end of which is connected to the main urea solution inlet pipe between the two urea solution inlet manual valves, and the other end is connected to the main urea solution inlet pipe between the two urea solution inlet manual valves. A regulating valve is installed on the urea solution inlet branch pipe.

[0014] The coil-type steam heating device and the electric heating unit are connected in parallel inside the hydrolyzer.

[0015] The electric heating unit includes an electric heating tube, and a stainless steel sleeve is wrapped around the electric heating tube. The stainless steel sleeve is made of stainless steel pipe of grade no lower than SS316L.

[0016] The DCS system receives real-time electricity price signals and controls the operation of the electric heating unit according to the positive or negative electricity price to maintain the hydrolyzer's operating temperature between 120-160℃ and the operating pressure at 0.55MPa.

[0017] The advantages of this utility model are:

[0018] 1. It can prevent the hydrolyzer from failing to produce product gas properly when the auxiliary steam supply is insufficient;

[0019] 2. It can enable electric heating during periods of low or negative electricity prices, reducing the amount of electricity fed into the grid and thus reducing electricity costs. It also saves more auxiliary steam to meet the gas consumption of the main equipment and for external industrial steam supply, improving equipment reliability and increasing economic benefits for enterprises. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the main structure of this utility model. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result of the description. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solution of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0022] See Figure 1 This utility model relates to a novel urea hydrolyzer, comprising a hydrolyzer body and further comprising:

[0023] The saturated steam inlet assembly is connected to the hydrolyzer body 11 and is used to introduce saturated steam.

[0024] The urea solution inlet assembly is connected to the hydrolyzer body 11 and is used to introduce urea solution; the hydrophobic assembly is connected to the hydrolyzer body and is used to discharge hydrophobic material.

[0025] An electric heating unit 12 is installed inside the hydrolyzer body 11 and is used to provide heating when the auxiliary steam pressure is insufficient.

[0026] A coil-type steam heating unit is used to provide heating when the auxiliary steam pressure is sufficient;

[0027] DCS system 13 is connected to electric heating unit 12 and is used to automatically control the power of electric heating unit 12 according to real-time electricity price.

[0028] Based on the above structural design, the following advantages are achieved:

[0029] Multifunctional heating system: By combining a coil-type steam heater and an electric heating unit, the hydrolyzer can provide stable heating under different operating conditions. When the auxiliary steam pressure is sufficient, the coil-type steam heater is used for heating; when the auxiliary steam pressure is insufficient, the electric heating unit can provide the necessary heating to ensure the continuity and stability of the hydrolysis reaction.

[0030] Intelligent control: The DCS system is connected to the electric heating unit and can automatically adjust the power output of the electric heating unit based on real-time electricity prices. This intelligent control not only optimizes energy efficiency but also reduces unnecessary energy consumption during periods of low or negative electricity prices, thereby lowering operating costs.

[0031] Improved safety: By reducing reliance on auxiliary steam, especially when auxiliary steam supply is insufficient, the use of electric heating units can ensure the normal operation of the hydrolyzer and avoid production interruptions due to insufficient steam pressure, thereby improving the safety of the entire system.

[0032] High environmental adaptability: The hydrolyzer is designed with market and environmental fluctuations in mind, such as the uncertainty of time-of-use electricity prices in the spot market and the supply of auxiliary steam, enabling it to adapt to changing industrial environments.

[0033] The saturated steam intake assembly includes a saturated steam intake pipe 14, one end of which is connected to a saturated steam source and the other end is connected to the steam inlet of the hydrolyzer body 11. On the saturated steam intake pipe 14, a manual valve 1 for steam intake, a pneumatic valve 2 for steam intake, and a manual valve 3 for steam intake are installed sequentially along the flow direction of the saturated steam.

[0034] The saturated steam inlet assembly structure described above has the following advantages:

[0035] High controllability: By sequentially installing a manual valve before steam inlet, a pneumatic valve for steam inlet, and a manual valve after steam inlet on the saturated steam inlet pipe, precise control of steam flow can be achieved. This multi-stage control structure improves the system's response speed and regulation accuracy.

[0036] Enhanced safety: The combination of manual valves and pneumatic control valves allows for manual control of steam flow in the event of a malfunction in the automatic control system, thereby ensuring the safe operation of the system.

[0037] The urea solution inlet assembly includes a main urea solution inlet pipe 15, one end of which forms a urea solution inlet, and the other end which is connected to the solution inlet of the hydrolyzer body. A urea solution inlet manual valve 5, a urea solution inlet manual valve 6, a urea solution inlet pneumatic regulating valve 7, a urea solution inlet manual valve 8, and a urea solution inlet manual valve 9 are sequentially installed on the main urea solution inlet pipe 15 between the urea solution inlet manual valve 5 and the urea solution inlet manual valve 6. The assembly also includes a urea solution inlet branch pipe 16, one end of which is connected to the main urea solution inlet pipe 15 between the urea solution inlet manual valve 5 and the urea solution inlet manual valve 6, and the other end is connected to the main urea solution inlet pipe 15 between the urea solution inlet manual valve 8 and the urea solution inlet manual valve 9. A regulating valve is installed on the urea solution inlet branch pipe 16.

[0038] The urea solution inlet assembly structure described above has the following advantages:

[0039] Multiple control points: By sequentially installing multiple manual valves and one pneumatic control valve on the main urea solution inlet pipeline, precise control of the urea solution flow rate can be achieved. This multiple control point design improves the system's regulation accuracy and response speed.

[0040] High flexibility: The urea solution inlet branch pipe and its regulating valve provide additional flow regulation capability, allowing the system to flexibly adjust the supply of urea solution according to different production needs.

[0041] Enhanced safety: The installation of multiple manual valves allows for manual control of the urea solution flow in the event of a malfunction in the automatic control system, thereby ensuring the safe operation of the system.

[0042] Easy maintenance: Due to the clear layout of the valves, maintenance and inspection can be carried out more conveniently, reducing maintenance time and costs.

[0043] The coil-type steam heating device and the electric heating unit 12 are connected in parallel inside the hydrolyzer.

[0044] The electric heating unit 12 includes an electric heating tube, and a stainless steel sleeve is wrapped around the electric heating tube. The stainless steel sleeve is made of stainless steel pipe of grade no lower than SS316L.

[0045] The hydrolyzer body 11 is equipped with both a coil-type steam heating device and an electric heating unit. When the electricity price is positive and the auxiliary steam pressure is sufficient, only the steam heater is activated; when the electricity price is negative, the electric heater is activated, and the saturated steam inlet regulating valve is closed to a minimum of 5% to maintain warm pipes. The DCS system 13 controls the activation of the electric heater according to the positive or negative electricity price to maintain the normal operating temperature of the hydrolyzer body 11 between 120-160℃ and the operating pressure at 0.55MPa.

[0046] The working principle of this utility model is as follows:

[0047] Saturated steam inlet assembly: Saturated steam is introduced into the hydrolyzer body 11 through saturated steam inlet pipe 14. The steam inlet pipe is sequentially equipped with a manual steam inlet valve 1, a pneumatic steam inlet valve 2, and a manual steam inlet valve 3 for precise control of steam flow.

[0048] When the auxiliary steam pressure is sufficient, the coil-type steam heating device is used to heat the urea solution.

[0049] Urea solution inlet assembly: Urea solution is introduced into the hydrolyzer body 11 through the urea solution inlet main pipe 15. Multiple manual valves and one pneumatic control valve are installed sequentially on the pipe for precise control of the urea solution flow rate.

[0050] The urea solution inlet branch pipe 16 and its regulating valve provide additional flow regulation capabilities to adapt to different production needs.

[0051] Electric heating unit: When the auxiliary steam pressure is insufficient, the electric heating unit 12 provides the necessary heating. The electric heating tube is wrapped with a stainless steel sleeve, using stainless steel pipe of grade no lower than SS316L to prevent corrosion.

[0052] The DCS system 13 automatically controls the power input of the electric heating unit according to the real-time electricity price to maintain the working temperature of the hydrolyzer body 11 between 120-160℃ and the working pressure at 0.55MPa.

[0053] Intelligent control: The DCS system 13 is connected to the electric heating unit 12 and controls the operation of the electric heater according to the positive or negative electricity price. When the electricity price is positive and the auxiliary steam pressure is sufficient, only the steam heater is used; when the electricity price is negative, the electric heater is activated and the saturated steam inlet regulating valve is closed to the minimum 5% opening to maintain warm pipes.

[0054] Based on the structural design of this utility model, the following advantages are achieved:

[0055] Multifunctional heating system: Combining a coil-type steam heating device and an electric heating unit, the hydrolyzer can provide stable heating under different operating conditions, ensuring the continuity and stability of the hydrolysis reaction.

[0056] Intelligent control: The DCS system automatically adjusts the power of the electric heating unit based on real-time electricity prices, optimizing energy efficiency and reducing operating costs.

[0057] Improved safety: By reducing reliance on auxiliary steam, the use of electric heating units can ensure the normal operation of the hydrolyzer and avoid production interruptions due to insufficient steam pressure.

[0058] High environmental adaptability: The design takes into account market and environmental fluctuations, such as the uncertainty of time-of-use electricity prices in the spot market and auxiliary steam supply, enabling it to adapt to changing industrial environments.

[0059] High controllability: The multi-stage control structure of the saturated steam inlet assembly and the urea solution inlet assembly improves the system's response speed and adjustment accuracy.

[0060] High flexibility: The urea solution inlet branch pipe and its regulating valve provide additional flow regulation capabilities, allowing the system to flexibly adjust the supply of urea solution according to different production needs.

[0061] Enhanced safety: The combination of manual valves and pneumatic control valves allows for manual control of the flow of steam and urea solution in the event of a malfunction in the automatic control system, ensuring safe operation of the system.

[0062] Easy maintenance: The valve layout is clear, making maintenance and inspection easier and reducing maintenance time and costs.

[0063] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A novel urea hydrolyzer, comprising a hydrolyzer body, characterized in that, Also includes: The saturated steam inlet assembly is connected to the main body of the hydrolyzer and is used to introduce saturated steam. The urea solution inlet assembly is connected to the main body of the hydrolyzer and is used to introduce urea solution. A hydrophobic component, connected to the main body of the hydrolyzer, is used to discharge hydrophobic material; An electric heating unit, located inside the hydrolyzer body, is used to provide heating when the auxiliary steam pressure is insufficient; A coil-type steam heating unit is used to provide heating when the auxiliary steam pressure is sufficient; The DCS system is connected to the electric heating unit and is used to automatically control the power of the electric heating unit based on the real-time electricity price.

2. The novel urea hydrolyzer according to claim 1, characterized in that, The saturated steam intake assembly includes a saturated steam intake pipe. One end of the saturated steam intake pipe is connected to a saturated steam source, and the other end is connected to the steam inlet of the hydrolyzer body. On the saturated steam intake pipe, a manual valve before steam intake, a pneumatic valve for steam intake, and a manual valve after steam intake are installed sequentially along the flow direction of the saturated steam.

3. The novel urea hydrolyzer according to claim 1 or 2, characterized in that, The urea solution inlet assembly includes a main urea solution inlet pipe, one end of which forms a urea solution inlet, and the other end which connects to the solution inlet of the hydrolyzer body. A urea solution inlet manual valve, a urea solution inlet pneumatic regulating valve, and another urea solution inlet manual valve are sequentially installed on the main urea solution inlet pipe between the urea solution inlet and the solution inlet of the hydrolyzer body. The assembly also includes a urea solution inlet branch pipe, one end of which is connected to the main urea solution inlet pipe between the two urea solution inlet manual valves, and the other end is connected to the main urea solution inlet pipe between the two urea solution inlet manual valves. A regulating valve is installed on the urea solution inlet branch pipe.

4. The novel urea hydrolyzer according to claim 1, characterized in that, The coil-type steam heating device and the electric heating unit are connected in parallel inside the hydrolyzer.

5. The novel urea hydrolyzer according to claim 4, characterized in that, The electric heating unit includes an electric heating tube, and a stainless steel sleeve is wrapped around the electric heating tube. The stainless steel sleeve is made of stainless steel pipe of grade no lower than SS316L.

6. The novel urea hydrolyzer according to claim 5, characterized in that, The DCS system receives real-time electricity price signals and controls the operation of the electric heating unit according to the positive or negative electricity price to maintain the hydrolyzer's operating temperature between 120-160℃ and the operating pressure at 0.55MPa.

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