Urea hydrolysis ammonia production system using waste heat for plant heating

Abstract

The utility model discloses a urea hydrolysis ammonia production system using waste heat for plant heating. The urea hydrolysis ammonia production system comprises a urea hydrolysis reactor, an energy-saving heat exchanger, a drain tank, a circulating water tank, a circulating water pump and a radiator, a steam drain outlet of the urea hydrolysis reactor is communicated with a heat source inlet of the energy-saving heat exchanger; a heat source outlet of the energy-saving heat exchanger is communicated with an inlet of the drain tank; a cold source inlet of the energy-saving heat exchanger communicates with an outlet of the circulating water pump; a cold source outlet of the energy-saving heat exchanger communicates with an inlet of the radiator; an inlet of the circulating water pump is communicated with an outlet of the circulating water tank; the urea hydrolysis reactor tank body is made of a titanium steel composite plate, and the steam coil pipe is made of duplex stainless steel. The system has the advantages that waste heat of the urea hydrolysis system is recycled for plant heating, the heat utilization rate is increased, and the operation cost is reduced; the visual pollution of white smoke is eliminated; and the service life of equipment in a corrosion environment is prolonged, and the stability and reliability of a production and plant heating system are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to atmospheric pollution control technical field, concretely is a kind of urea hydrolysis ammonia system for waste heat is used for factory building heating. BACKGROUND

[0002] The method for preparing ammonia gas by flue gas denitration at present mainly adopts urea hydrolysis ammonia preparation. When adopting urea hydrolysis ammonia preparation technology, heat source is usually selected as steam, steam is not mixed with urea solution, is backflowed through coil, and is recovered to drain tank as drain, and the collected drain is preferentially used for dissolving urea.

[0003] Only a small part of drain in conventional urea hydrolysis system can realize self-use, and most of the drain is discharged, so that the heat utilization rate is low. At the same time, urea hydrolysis factory building heating usually depends on independent external heating heat medium, which increases the overall heat consumption.

[0004] Due to the large amount of drain generated in the urea hydrolysis process, the high temperature of the drain and the entrainment of steam, the drain tank is prone to vibration, and the weld of the drain tank is prone to vibration cracking in severe cases. After encountering cold air on the top of the drain tank, liquid water is condensed and floats in the air, forming "white smoke" and causing visual pollution.

[0005] In addition, the urea hydrolysis system has strong corrosion, and the urea hydrolysis reactor tank body and the internal steam coil are prone to corrosion damage under such working conditions, so that the equipment maintenance and replacement are frequent, which seriously affects the continuity and stability of production.

[0006] Therefore, to provide a urea hydrolysis system which can not only efficiently recycle and utilize system waste heat for factory building heating, but also has excellent corrosion resistance and stability, is of great significance to improve production efficiency and achieve the goal of energy saving and emission reduction, and has become a problem to be solved by the technical personnel in the field. UTILITY MODEL CONTENTS

[0007] In view of the deficiencies of the prior art and in combination with the characteristics of the urea hydrolysis ammonia system, the utility model provides a urea hydrolysis ammonia system for waste heat used for factory building heating, which recycles steam drain heat for factory building heating, improves heat utilization rate, eliminates visual pollution, and reduces energy consumption and operating cost.

[0008] The utility model provides the following technical scheme: a urea hydrolysis ammonia system for waste heat used for factory building heating, which comprises a urea hydrolysis reactor, an energy-saving heat exchanger, a drain tank, a circulating water tank, a circulating water pump and a radiator.

[0009] The urea hydrolysis reactor comprises a heating steam inlet arranged at the upper part of the steam pipe box, a steam coil arranged in the urea hydrolysis reactor and a steam drain outlet arranged at the lower part of the steam pipe box, the heating steam inlet is in communication with the steam coil, and the steam drain outlet is in communication with the steam coil.

[0010] The steam hydrophobic outlet is communicated with the hydrophobic converging from the urea dissolving storage area through a pipeline with the energy-saving heat exchanger heat source inlet, the energy-saving heat exchanger heat source outlet is communicated with the hydrophobic tank inlet through a pipeline, the energy-saving heat exchanger cold source inlet is communicated with the circulating water pump outlet through a pipeline, the energy-saving heat exchanger cold source outlet is communicated with the radiator inlet through a pipeline, the circulating water pump inlet is communicated with the circulating water tank outlet through a pipeline, and the radiator outlet is communicated with the circulating water tank backwater inlet through a pipeline.

[0011] The urea hydrolysis reactor tank body adopts titanium steel composite plate, and the steam coil inside the urea hydrolysis reactor adopts duplex stainless steel.

[0012] Preferably, the energy-saving heat exchanger adopts a compact structure and is internally provided with high-efficiency heat exchange fins.

[0013] Preferably, the circulating water pump water supply flow is controlled by frequency conversion and a regulating valve.

[0014] Preferably, the radiator adopts a steel radiator or an aluminum alloy radiator.

[0015] Preferably, temperature sensors are arranged on the energy-saving heat exchanger heat source inlet and outlet pipelines, the cold source inlet and outlet pipelines and the heating system pipelines to monitor the temperature of the heating system in real time.

[0016] Compared with the prior art, the urea hydrolysis ammonia production system for plant heating has the following beneficial effects:

[0017] (1) The urea hydrolysis ammonia production system for plant heating utilizes the steam hydrophobic of the urea hydrolysis reactor and the urea dissolving storage area to heat the heating medium, improves the heat utilization rate, and reduces the overall heat consumption and operation cost.

[0018] (2) The urea hydrolysis ammonia production system for plant heating utilizes the steam hydrophobic of the urea hydrolysis reactor and the urea dissolving storage area to heat the heating medium, improves the heat utilization rate, and reduces the overall heat consumption and operation cost.

[0019] (3) The urea hydrolysis ammonia production system for plant heating utilizes the steam hydrophobic of the urea hydrolysis reactor and the urea dissolving storage area to heat the heating medium, improves the heat utilization rate, and reduces the overall heat consumption and operation cost. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0021] Figure 1 The structure diagram of the urea hydrolysis ammonia production system for heating a factory building by using waste heat.

[0022] In the figure: 1-urea hydrolysis reactor, 1.1-heating steam inlet, 1.2-heating coil, 1.3-steam drain outlet, 2-energy-saving heat exchanger, 3-drain tank, 4-circulating water tank, 5-circulating water pump, 6-radiator, 7-first valve, 8-second valve, 9-third valve, 10-fourth valve, 11-fifth valve, 12-sixth valve. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical features and advantages of the present application more clearly understood, the specific embodiments of the present application will be described with reference to the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0024] As Figure 1 shown, the present application provides a urea hydrolysis ammonia production system for heating a factory building by using waste heat, which comprises a urea hydrolysis reactor, an energy-saving heat exchanger, a drain tank, a circulating water tank, a circulating water pump and a radiator.

[0025] The urea hydrolysis reactor comprises a heating steam inlet arranged at the upper part of a steam pipe box, a steam coil arranged inside the urea hydrolysis reactor and a steam drain outlet arranged at the lower part of the steam pipe box, the heating steam inlet is in communication with the steam coil, and the steam drain outlet is in communication with the steam coil.

[0026] The steam drain outlet is in communication with the drain from the urea dissolution storage area through a pipeline and a heat source inlet of the energy-saving heat exchanger, a heat source outlet of the energy-saving heat exchanger is in communication with the inlet of the drain tank through a pipeline; a cold source inlet of the energy-saving heat exchanger is in communication with the outlet of the circulating water pump through a pipeline, and a cold source outlet of the energy-saving heat exchanger is in communication with the inlet of the radiator through a pipeline; the inlet of the circulating water pump is in communication with the outlet of the circulating water tank through a pipeline, and the outlet of the radiator is in communication with the backwater inlet of the circulating water tank through a pipeline.

[0027] The urea hydrolysis reactor tank adopts a titanium steel composite plate, the outer layer of which is made of high-strength carbon steel material to provide stable structural support and ensure the structural integrity of the equipment under high temperature and high pressure. The inner layer of titanium metal has excellent corrosion resistance and can effectively resist the corrosion of various corrosive substances generated during the urea hydrolysis process, thereby greatly prolonging the service life of the equipment.

[0028] The steam coil inside the urea hydrolysis reactor is made of duplex stainless steel 2205, 2507, etc. Since the duplex stainless steel heat exchange pipe has excellent corrosion resistance, the overall service life of the urea hydrolysis reactor can be significantly prolonged, the maintenance cost is reduced, and the continuity and reliability of production are ensured.

[0029] The energy-saving heat exchanger adopts a compact structure, and high-efficiency heat exchange fins are arranged inside to increase the heat exchange area and significantly improve the heat exchange efficiency. The surface of the heat exchanger is coated with a high-temperature-resistant and corrosion-resistant coating to ensure stable operation under harsh conditions and continuously and efficiently recover the waste heat.

[0030] The water supply flow of the circulating water pump is controlled by frequency conversion and a regulating valve. Temperature sensors are arranged on the heat source inlet and outlet pipelines, the cold source inlet and outlet pipelines, and the heating system pipelines of the energy-saving heat exchanger to monitor the temperature of the heating system in real time. The temperature sensors transmit signals to the control system, and the control system automatically and accurately controls the frequency of the circulating water pump and the opening degree of the regulating valve according to the real-time demand of the heating system, thereby controlling the circulating water quantity. While ensuring the heating effect, the energy consumption is minimized to realize energy-saving operation.

[0031] The radiator adopts a steel or aluminum alloy finned radiator, which is uniformly distributed in each area of the plant. When the high-temperature circulating water flows in the pipeline inside the radiator, the heat is first transferred from the circulating water to the inner wall of the radiator by heat conduction, and then transferred to the fins of the radiator. Subsequently, through heat convection, the heated air around the radiator constantly rises, and the relatively cold air around the radiator quickly supplements, forming a natural convection cycle of air, rapidly transferring heat to each space of the plant, and providing a comfortable heating environment for the plant.

[0032] The utility model will be further described in connection with the embodiments as follows.

[0033] The embodiment provides a urea hydrolysis ammonia production system for plant heating, as shown in Figure 1

[0034] The steam and water outlet of the urea hydrolysis reactor and the water outlet from the urea dissolution and storage area are combined and then enter the energy-saving heat exchanger heat source inlet to heat the heating system heat medium. The cooled water enters the water tank and is used for the urea hydrolysis system. The steam and water are cooled to eliminate the vibration of the water tank and "white smoke" visual pollution, and ensure the stable operation of the system.​

[0035] Open the first valve, the fourth valve, by the external heating heat medium water pipe to the circulating water tank water supplement. After the circulating water tank liquid level meets the heating system usage, close the first valve, the fourth valve, open the fifth valve, the sixth valve, start the circulating water pump, the heating return water is discharged to the circulating water tank return water after the radiator, the energy-saving heat exchanger uses the urea hydrolysis system waste heat, the heating system normal operation. The circulating water heated by the energy-saving heat exchanger is driven by the circulating water pump into the radiator in the factory building. The frequency of the circulating water pump and the opening degree of the regulating valve are controlled to ensure that the circulating water flow and the factory building heating demand are accurately matched, and energy waste is avoided. The radiator releases the heat of the circulating water to the air in the factory building to realize factory building heating. Then, the low-temperature circulating water flows to the energy-saving heat exchanger to absorb the waste heat of the urea hydrolysis reactor and the urea dissolution storage area steam drain again, forming a continuous heating cycle.

[0036] When the urea hydrolysis system is shut down, the energy-saving heat exchanger stops working, at this time, the fifth valve, the sixth valve are closed, the circulating water pump is closed, the first valve, the second valve, the third valve are opened, the external heating heat medium water pipe provides heat medium for the factory building heating system, the heating return water is discharged to the external heating heat medium return water pipe after the radiator and the third valve, the heating system temporarily uses the external heating heat medium to run. After the urea hydrolysis system is put into operation, the first valve, the second valve, the third valve are closed, the fifth valve, the sixth valve are opened, the circulating water pump is started, the energy-saving heat exchanger uses the waste heat of the urea hydrolysis system, and the heating system resumes normal operation.

[0037] The urea hydrolysis reactor tank body adopts titanium steel composite plate, and the internal steam coil pipe adopts duplex stainless steel, which prolongs the service life of the urea hydrolysis reactor in the corrosion environment, reduces the frequency of equipment maintenance and replacement, improves the continuity of urea hydrolysis system production, and further improves the stability and reliability of the factory building heating system.

[0038] The above is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A urea hydrolysis ammonia production system for heating a plant building using waste heat, characterized by: The energy-saving heat exchanger (2), the drain tank (3), the circulating water tank (4), the circulating water pump (5) and the radiator (6) are sequentially connected in series. The urea hydrolysis reactor (1) comprises a heating steam inlet (1.1) arranged at the upper part of a steam pipe box, a steam coil (1.2) arranged in the urea hydrolysis reactor (1), and a steam drain outlet (1.3) arranged at the lower part of the steam pipe box, wherein the heating steam inlet (1.1) is communicated with the steam coil (1.2), and the steam drain outlet (1.3) is communicated with the steam coil (1.2). The steam drain outlet (1.3) is communicated with the drain from the urea dissolving storage area through a pipeline and a heat source inlet of the energy-saving heat exchanger (2), the heat source outlet of the energy-saving heat exchanger (2) is communicated with an inlet of the drain tank (3) through a pipeline, the cold source inlet of the energy-saving heat exchanger (2) is communicated with an outlet of the circulating water pump (5) through a pipeline, the cold source outlet of the energy-saving heat exchanger (2) is communicated with an inlet of the radiator (6) through a pipeline, the inlet of the circulating water pump (5) is communicated with an outlet of the circulating water tank (4) through a pipeline, and the outlet of the radiator (6) is communicated with a backwater inlet of the circulating water tank (4) through a pipeline. The tank body of the urea hydrolysis reactor (1) is made of titanium steel composite plate, and the steam coil (1.2) arranged in the urea hydrolysis reactor (1) is made of duplex stainless steel.

2. The urea hydrolysis ammonia production system for heating a plant building by waste heat according to claim 1, characterized in that: The energy-saving heat exchanger (2) adopts a compact structure and is internally provided with high-efficiency heat exchange fins.

3. The urea hydrolysis ammonia production system for heating a plant building with waste heat according to claim 1, characterized in that: The water supply flow of the circulating water pump (5) is controlled by a frequency conversion control and a regulating valve control.

4. The urea hydrolysis ammonia production system for heating a plant building with waste heat according to claim 1, characterized in that: The radiator (6) is made of a steel radiator or an aluminum alloy radiator.

5. The urea hydrolysis ammonia production system for heating a plant building with waste heat according to claim 1, characterized in that: Temperature sensors are arranged on the heat source inlet and outlet pipeline, the cold source inlet and outlet pipeline and the heating system pipeline of the energy-saving heat exchanger (2) to monitor the temperature of the heating system in real time.

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