A solar water heating system dissolving urea granules to produce ammonia

Abstract

The invention discloses a device for preparing ammonia by dissolving urea particles in a solar hot water system. The water outlet of a solar vacuum glass collector is connected to the inlet of a heat preservation water tank, the outlet of the heat preservation water tank is connected to the inlet of a circulating water pump, and the outlet of the circulating water pump is divided into three paths, wherein the first path is connected to the inlet of a dissolving tank, the second path is connected to the inlet of a tubular heat exchanger in a storage tank, the third path is connected to the water inlet of the solar vacuum glass collector, the outlet of the tubular heat exchanger in the storage tank is connected to the inlet of the dissolving tank, the outlet of the dissolving tank is connected to the inlet of the storage tank, the outlet of the storage tank is connected to the inlet of a hydrolysis reactor, a pyrolysis furnace or a boiler spray gun; a desalted water pipeline is connected to the inlet of the heat preservation water tank, and the outlet of the urea particle storage tank is connected to the dosing port of the dissolving tank. The device can ensure safe and reliable dissolution of urea particles and has the characteristics of low cost, short waiting time and low power consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of denitration SCR reducing agent solution in thermal power plants, and relates to a device for preparing ammonia by dissolving urea particles through a solar water heating system. Background Art

[0002] When liquid ammonia and ammonia water are used as denitrification SCR reducing agents, there are great safety hazards during storage, transportation and use. Therefore, in recent years, thermal power plants have gradually adopted urea as a reducing agent to produce ammonia.

[0003] The urea ammonia production system consists of a urea granule storage and dissolution system, a urea solution storage and delivery system, and a urea decomposition system. According to the different urea ammonia production processes, there are currently five main technical solutions for urea ammonia production processes, including urea hydrolysis, urea catalytic hydrolysis, urea thermal decomposition (electric heating), urea thermal decomposition (flue gas heat exchange), and urea direct injection. Regardless of which ammonia production process is used, urea granules need to be configured into a certain proportion of urea solution, desalted water is added to the urea dissolving tank, steam is drawn from the steam pipe of the unit, and the desalted water in the dissolving tank is heated by a tubular heat exchanger or an electric heater. The temperature of the desalted water is heated to above 80 degrees Celsius, and the granules in the bagged urea or urea tank truck are sent to the dissolving tank for dissolution. The urea solution is stirred evenly by an agitator, and the configured urea solution is pumped into the urea solution storage tank by a urea dissolving pump. The urea solution in the storage tank is kept warm by coil heat exchange, and the urea solution in the storage tank is sent to the hydrolysis reactor, the pyrolysis furnace or the urea spray gun in front of the boiler furnace by a urea solution delivery pump.

[0004] Heating desalted water with steam to dissolve urea granules and to insulate the urea solution storage tank has the advantages of fast heating speed, high reliability, convenience and flexibility. Since the urea solution preparation workshop is generally far away from the main steam or auxiliary steam main pipe, the introduction of steam into the urea solution preparation room requires the construction of a new process pipeline corridor, including civil excavation and foundation production, pipeline insulation, anti-corrosion and other work. The steam pipeline must be cooled and depressurized before entering the dissolution tank. The amount of drain generated by condensation is large, and additional drain tanks, drain pumps, valves and measuring instruments are required. The system is complex, the engineering volume is large, the construction period is long, and many disciplines are involved. The construction cost accounts for a large proportion of the entire project.

[0005] Dissolving urea particles by electrically heating desalted water and keeping the urea solution storage tank warm has the advantages of simple system, low cost, short construction period and convenient operation. However, low-power electric heaters heat desalted water slowly and require long waiting time, which affects the efficiency of configuring urea solution. High-power electric heaters have high requirements for power capacity and require multiple electric heaters. Long-term operation has high power consumption, which has a great impact on the capacity of the plant power bus and has high maintenance costs. Therefore, this process is only suitable for urea solution preparation systems in small power plants. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a device for dissolving urea granules to produce ammonia in a solar water heating system, which can ensure the safe and reliable dissolution of urea granules and has the characteristics of low cost, short waiting time and low power consumption.

[0007] To achieve the above-mentioned purpose, the solar water heating system urea dissolving ammonia production device of the present invention comprises a solar vacuum glass collector, an insulation water tank, a circulating water pump, a dissolving tank, a storage tank, a hydrolysis reactor, a pyrolysis furnace or a boiler spray gun, a wastewater tank, a urea granule storage tank and a desalted water pipeline;

[0008] The water outlet of the solar vacuum glass collector is connected to the inlet of the insulation water tank, the outlet of the insulation water tank is connected to the inlet of the circulating water pump, and the outlet of the circulating water pump is divided into three routes, wherein the first route is connected to the inlet of the dissolution tank, the second route is connected to the inlet of the tubular heat exchanger in the storage tank, and the third route is connected to the water inlet of the solar vacuum glass collector, the outlet of the tubular heat exchanger in the storage tank is connected to the inlet of the dissolution tank, the outlet of the dissolution tank is connected to the inlet of the storage tank, and the outlet of the storage tank is connected to the inlet of the hydrolysis reactor, the pyrolysis furnace or the boiler spray gun;

[0009] The desalted water pipeline is connected with the inlet of the insulation water tank, and the outlet of the urea granule storage tank is connected with the dosing port of the dissolution tank.

[0010] It also includes a wastewater pool; the wastewater pool is connected with the sewage outlet of the insulation water tank, the sewage outlet of the dissolution tank and the sewage outlet of the storage tank.

[0011] A liquid level meter is arranged in the wastewater pool, and the outlet of the wastewater pool is connected to a wastewater pump, wherein the wastewater pump is interlocked with the liquid level meter.

[0012] An electric heater is arranged in the thermal insulation water tank, and a temperature sensor is arranged in the thermal insulation water tank, and the temperature sensor is interlocked with the electric heater.

[0013] A stirrer is provided in the dissolving tank.

[0014] The outlet of the dissolving tank is connected to the inlet of the storage tank via a dissolving pump.

[0015] The outlet of the storage tank is connected to the inlet of the hydrolysis reactor, pyrolysis furnace or boiler spray gun through a delivery pump.

[0016] It also includes a remote control room; the remote control room is connected with the agitator, the wastewater pump, the circulating water pump, the dissolving pump and the conveying pump.

[0017] The present invention has the following beneficial effects:

[0018] When the solar water heating system dissolving urea granules to produce ammonia is operated, the cold water in the insulated water tank is transported to the solar vacuum glass collector by a circulating water pump, and the hot water is sent to the insulated water tank for storage after heat exchange with the solar energy, and then the hot water is transported to the dissolution tank by the circulating water pump, and the urea granules in the bagged urea or the tank truck are transported to the dissolution tank to form a urea solution, and the configured urea solution is sent to the storage tank, and then the solution in the storage tank is transported to the hydrolysis reactor, the pyrolysis furnace or the boiler spray gun. It should be noted that the present invention sends the hot water in the insulated water tank into the tubular heat exchanger through the circulating water pump to be insulated with the urea solution in the storage tank, and does not need to introduce steam, thereby reducing a large amount of steam and drain pipes, eliminating the drain tank and the corresponding drain pump, eliminating the temperature reduction and pressure reduction system, and completely using solar energy to heat the desalted water to dissolve the urea granules. At night, in extreme weather and when the vacuum collector is under maintenance, the desalted water can be heated by an electric heater to maintain a constant temperature in the insulated water tank. It should be noted that the present invention can greatly reduce the amount of process pipeline materials, reduce the amount of civil construction and related work such as pipeline insulation and anti-corrosion. Due to the reduction in steam consumption, the efficiency of the steam turbine is improved, and the effect is more significant for some power plants with tight steam supply or far away from the steam main pipe. For some enterprises located in the city center, it is particularly necessary to reduce unnecessary pipelines and structures because the public has high requirements for the appearance of the factory. The present invention heats desalted water through solar energy, which is both environmentally friendly and economical. The solar vacuum glass collector can be arranged on the top of the urea dissolution workshop, which does not affect the appearance and does not require additional floor space. Due to the reduction of pipelines, the available area of ​​the urea dissolution workshop becomes larger, and more bagged urea can be stacked, so it has greater economic benefits and market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Among them, 1 is a solar vacuum glass collector, 2 is an insulated water tank, 3 is a circulating water pump, 4 is a dissolution tank, 5 is a dissolution pump, 6 is a storage tank, 7 is a delivery pump, 8 is a hydrolysis reactor, a pyrolysis furnace or a boiler spray gun, 9 is a wastewater pool, 10 is a urea granule storage tank, 11 is a desalted water pipeline, and 12 is a remote control room. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0022] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0023] refer to Figure 1 The solar water heating system urea dissolving ammonia production device of the present invention comprises a solar vacuum glass collector 1, an insulation water tank 2, a circulating water pump 3, a dissolving tank 4, a dissolving pump 5, a storage tank, a delivery pump 7, a hydrolysis reactor, a pyrolysis furnace or a boiler spray gun 8, a wastewater tank 9, a urea granule storage tank 10, a desalted water pipeline 11 and a remote control room 12;

[0024] The water outlet of the solar vacuum glass collector 1 is connected to the inlet of the insulation water tank 2, the outlet of the insulation water tank 2 is connected to the inlet of the circulating water pump 3, and the outlet of the circulating water pump 3 is divided into three routes, wherein the first route is connected to the inlet of the dissolution tank 4, the second route is connected to the inlet of the tubular heat exchanger in the storage tank 6, and the third route is connected to the water inlet of the solar vacuum glass collector 1, the outlet of the tubular heat exchanger in the storage tank 6 is connected to the inlet of the dissolution tank 4, the outlet of the dissolution tank 4 is connected to the inlet of the dissolution pump 5, the outlet of the dissolution pump 5 is connected to the inlet of the storage tank 6, and the outlet of the storage tank 6 is connected to the inlet of the hydrolysis reactor, the pyrolysis furnace or the boiler spray gun 8 through the delivery pump 7; the desalted water pipeline 11 is connected to the inlet of the insulation water tank 2, and the outlet of the urea granule storage tank 10 is connected to the dosing port of the dissolution tank 4.

[0025] The wastewater pool 9 is connected with the sewage outlet of the thermal insulation water tank 2 , the sewage outlet of the dissolving tank 4 and the sewage outlet of the storage tank 6 .

[0026] A liquid level meter is arranged in the wastewater pool 9, and an outlet of the wastewater pool 9 is connected to a wastewater pump, wherein the wastewater pump is interlocked with the liquid level meter.

[0027] An electric heater is arranged in the heat preservation water tank 2, and a temperature sensor is arranged in the heat preservation water tank 2, and the temperature sensor is interlocked with the electric heater.

[0028] The dissolving tank 4 is provided with a stirrer.

[0029] The remote control room 12 is connected with the temperature sensor, the stirrer, the electric heater, the wastewater pump, the liquid level meter, the circulating water pump 3 , the dissolving pump 5 and the delivery pump 7 .

[0030] When the present invention is in specific operation,

[0031] The cold water in the insulated water tank 2 is transported to the solar vacuum glass collector 1 through the circulating water pump 3, and the hot water is sent to the insulated water tank 2 for storage after solar heat exchange. The water temperature of the insulated water tank 2 is detected by the temperature sensor. When the water temperature in the insulated water tank 2 reaches the preset temperature, the hot water in the insulated water tank 2 is transported to the dissolution tank 4 through the circulating water pump 3, and the bagged urea or urea granules in the tank truck are transported to the dissolution tank 4, and are stirred by the agitator to form a urea solution. When the temperature of the desalted water in the insulated water tank 2 is low, an electric heater can be used for heating. The dissolution pump 5 sends the configured urea solution to the storage tank 6, and the solution in the storage tank 6 is transported to the hydrolysis reactor, the pyrolysis furnace or the boiler spray gun 8 through the delivery pump 7.

[0032] The temperature signal in the insulated water tank 2 is fed back to the remote control room 12 through the temperature sensor. The remote control room 12 controls the start and stop of the circulating water pump 3 after judgment. When the water temperature in the insulated water tank 2 meets the temperature for dissolving urea, the hot water in the insulated water tank 2 is sent to the dissolving tank 4. The urea solution in the dissolving tank 4 is stirred evenly by the stirrer. The dissolved urea solution is transferred to the storage tank 6 by the dissolving pump 5. The storage tank 6 is provided with a tubular heat exchanger. The urea solution in the insulated water tank 2 is stirred evenly by the circulating water pump 3. The hot water is sent to the tubular heat exchanger to exchange heat with the urea solution in the storage tank 6, and the urea solution in the storage tank 6 is sent to the hydrolysis reactor, pyrolysis furnace or boiler spray gun 8 for reaction through the delivery pump 7, thereby realizing denitrification. Among them, the replenishment water of the insulated water tank 2 comes from the desalted water in the factory area, and the overflow and sewage pipes of the insulated water tank 2, the dissolution tank 4 and the storage tank 6 are combined to flow into the wastewater pool 9, which is interlocked by the wastewater pump and the liquid level sensor, and automatically controlled by the remote control room 12 to pump the waste liquid to a unified collection point.

Claims

1. A solar water heating system dissolving urea to produce ammonia device, characterized in that: It comprises a solar vacuum glass collector (1), an insulated water tank (2), a circulating water pump (3), a dissolving tank (4), a storage tank (6), a hydrolysis reactor, a pyrolysis furnace or a boiler spray gun (8), a wastewater pool (9), a urea granule storage tank (10) and a desalted water pipeline (11); The water outlet of the solar vacuum glass collector (1) is connected to the inlet of the insulation water tank (2), the outlet of the insulation water tank (2) is connected to the inlet of the circulating water pump (3), and the outlet of the circulating water pump (3) is divided into three paths, wherein the first path is connected to the inlet of the dissolution tank (4), the second path is connected to the inlet of the tubular heat exchanger in the storage tank (6), and the third path is connected to the water inlet of the solar vacuum glass collector (1), the outlet of the tubular heat exchanger in the storage tank (6) is connected to the inlet of the dissolution tank (4), the outlet of the dissolution tank (4) is connected to the inlet of the storage tank (6), and the outlet of the storage tank (6) is connected to the inlet of the hydrolysis reactor, the pyrolysis furnace or the boiler spray gun (8); The desalted water pipeline (11) is connected to the inlet of the heat preservation water tank (2), and the outlet of the urea granule storage tank (10) is connected to the dosing port of the dissolution tank (4); A stirrer is arranged in the dissolving tank (4); The outlet of the dissolving tank (4) is connected to the inlet of the storage tank (6) via the dissolving pump (5); The outlet of the storage tank (6) is connected to the inlet of the hydrolysis reactor, pyrolysis furnace or boiler lance (8) via a delivery pump (7); It also includes a remote control room (12); the remote control room (12) is connected to the agitator, the wastewater pump, the circulating water pump (3), the dissolving pump (5) and the delivery pump (7); It also includes a wastewater pool (9); the wastewater pool (9) is connected to the sewage outlet of the thermal insulation water tank (2), the sewage outlet of the dissolving tank (4) and the sewage outlet of the storage tank (6).

2. The solar water heating system urea dissolving ammonia production device according to claim 1, characterized in that: A liquid level meter is arranged in the wastewater pool (9), and the outlet of the wastewater pool (9) is connected to a wastewater pump, wherein the wastewater pump is interlocked with the liquid level meter.

3. The solar water heating system urea dissolving ammonia production device according to claim 1, characterized in that: An electric heater is arranged in the thermal insulation water tank (2), and a temperature sensor is arranged in the thermal insulation water tank (2), wherein the temperature sensor is interlocked with the electric heater.

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