Urea hydrolysis reactor capable of efficiently recycling drain waste heat

Abstract

The utility model discloses a urea hydrolysis reactor capable of efficiently recovering drain waste heat, which comprises a urea hydrolysis reactor main body, a heat pipe heat exchanger is arranged outside the urea hydrolysis reactor main body, a drain passage and a urea solution passage of the urea hydrolysis reactor main body are communicated with the heat pipe heat exchanger, and the heat pipe heat exchanger is composed of a heat pipe array. The cold fluid and the hot fluid are arranged up and down or horizontally. According to the utility model, the heat pipe heat exchanger is externally arranged, so that drainage waste heat can be efficiently recovered, energy waste is reduced, and cost is saved; the heat pipe heat exchanger is good in heat pipe temperature uniformity, small in heat transfer temperature difference and capable of reducing the heat exchange area, the heat exchange area of the heat pipe heat exchanger is increased through fins, the specific heat exchange area is large, the size and weight of the heat exchanger can be reduced, meanwhile, the heat pipe heat exchanger is large in flow area, and compared with a traditional heat exchanger, the heat pipe heat exchanger is small in flow resistance and small in power consumption needed by driving fluid.

Description

Technical Field

[0001] The utility model relates to the field of urea hydrolysis equipment, in particular to a urea hydrolysis reactor for efficiently recovering hydrophobic waste heat. Background Art

[0002] The urea hydrolysis reactor is a device for hydrolyzing urea solution. Urea solution with a concentration of about 50% is transported from the urea storage tank to the urea hydrolysis reactor. Saturated steam at 170°C and 0.7MPa is introduced into the built-in U-shaped heating coil of the urea hydrolysis reactor to heat the urea solution, so that it undergoes hydrolysis reaction at a temperature of 130-140°C and a pressure of 0.35-0.55MPa to generate a mixed gas containing NH3, CO2 and H2O.

[0003] After saturated steam releases heat, it forms a drain with a temperature of about 130-140℃ and 0.3-0.4MPa, which is discharged into the normal pressure drain tank after passing through the drain valve. Due to the sudden drop in pressure, the drain will flash and release a large amount of steam, so desalted water needs to be added to the drain tank as cooling water. This not only wastes the waste heat carried by the drain, but also increases the consumption of desalted water, increases operating costs, and fails to achieve the best effect of energy saving and environmental protection. At present, the most commonly used method is to recycle the drain and use the waste heat of the drain in a cascade, such as using it instead of desalted water to heat and dissolve urea particles in the urea dissolution system, passing it into the urea solution storage tank through a pipeline to maintain the temperature of the urea solution, and heating the urea solution delivery pipeline, etc., to further reduce the temperature and pressure of the drain before returning it to the drain tank. There is also a way to preheat the urea solution with hydrophobicity, such as a urea hydrolysis hydrophobic waste heat cascade energy system disclosed in Chinese patent document CN 215667167 U. The utility model sets a heat exchanger outside the hydrolysis reactor and connects it to the urea solution storage tank to circulate and absorb the heat of hydrophobicity. The temperature of the urea solution after heat exchange in the heat exchanger is 70-90°C, and the temperature of the hydrophobicity after heat exchange in the heat exchanger is 90°C. According to the description, this method has a complex system and a long distance for the pipeline layout, which will cause the heat to be lost during the transportation of the hydrophobicity and cannot be fully utilized, and the selection of the heat exchanger is not introduced in detail.

[0004] In order to solve the above problems, the present utility model is hereby proposed. Utility Model Content

[0005] The utility model aims to provide a urea hydrolysis reactor which can efficiently recover hydrophobic waste heat.

[0006] One purpose of the utility model can be achieved by the following technical solutions:

[0007] A urea hydrolysis reactor for efficiently recovering hydrophobic waste heat comprises a urea hydrolysis reactor body. A heat pipe heat exchanger is arranged outside the urea hydrolysis reactor body. The hydrophobic passage and the urea solution passage of the urea hydrolysis reactor body are connected to the heat pipe heat exchanger. The heat pipe heat exchanger is composed of a heat pipe array. Cold and hot fluids are arranged in an up-and-down manner or in a horizontal manner.

[0008] Furthermore, a steam input port is provided in the middle of one end of the urea hydrolysis reactor body.

[0009] Preferably, a drain port is provided below one end of the urea hydrolysis reactor body, the heat pipe heat exchanger is provided with a drain inlet, the drain port and the drain inlet are connected through a pipeline, the heat pipe heat exchanger is provided with a drain outlet, and the drain outlet is connected to the drain tank through a pipeline.

[0010] Preferably, the heat pipe heat exchanger is also provided with a urea solution inlet, which is connected to the urea solution storage tank through a pipeline, the heat pipe heat exchanger is provided with a urea solution outlet, and the urea hydrolysis reactor body is provided with a urea solution addition port, and the urea solution addition port and the urea solution outlet are connected through a pipeline.

[0011] Preferably, a product gas outlet is provided above the urea hydrolysis reactor body.

[0012] Furthermore, when the heat pipe array of the heat pipe heat exchanger adopts a vertical arrangement of hot and cold fluids, the heat pipe heat exchanger is divided into upper and lower parts, with hot fluid flowing through the lower end and cold fluid flowing through the upper end.

[0013] Furthermore, when the heat pipe array of the heat pipe heat exchanger is arranged horizontally, hot fluid flows on one side and cold fluid flows on the other side.

[0014] Preferably, a thermal insulation layer is provided outside the heat pipe heat exchanger.

[0015] Preferably, an electric heating belt is provided on the connecting pipeline from the urea solution outlet to the urea solution addition port.

[0016] Furthermore, the heat pipe heat exchanger increases the heat exchange area through fins, which is larger than the heat exchange area, and is used to reduce the volume and weight of the heat exchanger.

[0017] Beneficial technical effects:

[0018] The utility model can efficiently recover the waste heat of drainage by externally provided with a heat pipe heat exchanger, reduce energy waste and save costs; the heat pipes of the heat pipe heat exchanger have good temperature uniformity and small heat transfer temperature difference, which can reduce the heat exchange area; the heat pipe heat exchanger increases the heat exchange area by fins, has a larger specific heat exchange area, and can reduce the volume and weight of the heat exchanger; at the same time, the heat pipe heat exchanger has a large flow area, has less flow resistance than traditional heat exchangers, and consumes less power to drive the fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The utility model is further described below in conjunction with the accompanying drawings.

[0020] Figure 1 Schematic diagram of a urea hydrolysis reactor device for efficiently recovering hydrophobic waste heat.

[0021] In the figure: 1. Urea hydrolysis reactor body; 2. Heat pipe heat exchanger; 3. Steam input port; 4. Drain port; 5. Drain inlet; 6. Urea solution inlet; 7. Drain outlet; 8. Urea solution addition port; 9. Urea solution outlet; 10. Product gas outlet. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] like Figure 1 As shown, a urea hydrolysis reactor for efficiently recovering hydrophobic waste heat includes a urea hydrolysis reactor body 1, a heat pipe heat exchanger 2 is arranged outside the urea hydrolysis reactor body 1, the hydrophobic passage and the urea solution passage of the urea hydrolysis reactor body 1 are connected to the heat pipe heat exchanger 2, the heat pipe heat exchanger 2 is composed of a heat pipe array, and the cold and hot fluids are arranged in an up-and-down manner or in a horizontal manner.

[0024] A steam input port 3 is provided in the middle of one end of the urea hydrolysis reactor body 1, a drain port 4 is provided below one end of the urea hydrolysis reactor body 1, a drain inlet 5 is provided on the heat pipe heat exchanger 2, the drain port 4 is connected with the drain inlet 5 through a pipeline, and is a drain flow pipeline. The heat pipe heat exchanger 2 is also provided with a urea solution inlet 6 and a drain outlet 7. The urea solution inlet 6 is connected with the urea solution storage tank through a pipeline, and the drain outlet 7 is connected with the drain tank through a pipeline, which is used for the recovery of drain for reuse as dissolved water, etc.

[0025] The heat pipe heat exchanger 2 is provided with a urea solution outlet 9, and the urea hydrolysis reactor body 1 is provided with a urea solution addition port 8, and the urea solution addition port 8 and the urea solution outlet 9 are connected through a pipeline.

[0026] A product gas outlet 10 is arranged above the urea hydrolysis reactor body 1 .

[0027] During operation, the saturated steam introduced through the steam input port 3 passes through the urea solution in the urea hydrolysis reactor body 1 and the high-temperature hydrophobic gas generated after the endothermic reaction of the urea solution is generated enters the heat pipe heat exchanger 2 through the hydrophobic port 4, and the low-temperature hydrophobic gas after continuing to release heat is discharged into the hydrophobic tank through the hydrophobic port 7. The urea solution from the urea solution storage tank passes through the urea solution inlet 6 and the heat pipe heat exchanger 2 and is preheated, and then is introduced into the urea hydrolysis reactor body 1 through the urea solution outlet 9 and the urea solution addition port 8 for hydrolysis reaction, and the ammonia-containing mixed gas is produced and discharged from the product gas outlet 10 into the denitration system.

[0028] Heat pipe is a heat transfer element with extremely high heat exchange efficiency. It uses phase change heat transfer of the working fluid in the heat pipe and has the advantages of good thermal conductivity and good temperature uniformity. The equivalent thermal conductivity of the heat pipe can reach the order of 105W / m·℃, which is hundreds or even thousands of times that of general metal materials.

[0029] When the heat pipe array of the heat pipe heat exchanger 2 is arranged in a way that the hot and cold fluids are arranged up and down, the heat pipe heat exchanger 2 is divided into two parts, the lower end is for hot fluid, and the upper end is for cold fluid, and gravity is fully utilized to assist the reflux of the working fluid in the heat pipe, which can enhance the heat transfer effect. The urea solution at the outlet of the heat exchanger can be preheated to about 110°C, and the drain outlet temperature can be reduced to about 60°C.

[0030] When the heat pipe array of the heat pipe heat exchanger 2 is arranged horizontally, hot fluid flows on one side and cold fluid flows on the other side.

[0031] Heat pipe heat exchanger 2 increases the heat exchange area through fins, with a specific heat exchange area of ​​up to 120m 2 / m 3 , which is much higher than traditional heat exchangers and can significantly reduce the size and weight of the heat exchanger.

[0032] A heat-insulating layer is arranged outside the heat pipe heat exchanger 2 to reduce heat loss.

[0033] According to the changes in external environmental conditions, an electric heating belt is installed in the connecting pipeline from the urea solution outlet to the urea solution addition port when necessary. The electric heating belt is used to increase the stability of the temperature of the urea solution outlet 9 to ensure the stable operation of the urea hydrolysis reactor.

[0034] The utility model adopts a high-efficiency heat exchange device, which can reduce the hydrophobic temperature to about 60° C. without utilizing the urea solution storage tank to absorb heat in a cycle, thereby improving the steam utilization rate of the urea hydrolysis reactor.

[0035] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0036] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A urea hydrolysis reactor for efficiently recovering hydrophobic waste heat, characterized in that: The invention comprises a urea hydrolysis reactor body (1), wherein a heat pipe heat exchanger (2) is arranged outside the urea hydrolysis reactor body (1), a hydrophobic passage and a urea solution passage of the urea hydrolysis reactor body (1) are connected to the heat pipe heat exchanger (2), the heat pipe heat exchanger (2) is composed of a heat pipe array, and the cold and hot fluids are arranged in an up-and-down manner or in a horizontal manner.

2. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 1, characterized in that: A steam input port (3) is provided in the middle of one end of the urea hydrolysis reactor body (1).

3. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 2, characterized in that: A drain port (4) is provided below one end of the urea hydrolysis reactor body (1); the heat pipe heat exchanger (2) is provided with a drain inlet (5); the drain port (4) and the drain inlet (5) are connected via a pipeline; the heat pipe heat exchanger (2) is provided with a drain outlet (7); and the drain outlet (7) is connected to a drain tank via a pipeline.

4. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 3, characterized in that: The heat pipe heat exchanger (2) is also provided with a urea solution inlet (6), which is connected to a urea solution storage tank via a pipeline. The heat pipe heat exchanger (2) is provided with a urea solution outlet (9), and the urea hydrolysis reactor body (1) is provided with a urea solution addition port (8), which is connected to the urea solution outlet (9) via a pipeline.

5. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 4, characterized in that: A product gas outlet (10) is provided above the urea hydrolysis reactor body (1).

6. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 1, characterized in that: When the heat pipe array of the heat pipe heat exchanger (2) adopts a method of arranging hot and cold fluids up and down, the heat pipe heat exchanger (2) is divided into an upper and lower part, with hot fluid flowing through the lower end and cold fluid flowing through the upper end.

7. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 1, characterized in that: When the heat pipe array of the heat pipe heat exchanger (2) is arranged horizontally, hot fluid flows on one side and cold fluid flows on the other side.

8. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 1, characterized in that: A thermal insulation layer is arranged outside the heat pipe heat exchanger (2).

9. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 4, characterized in that: An electric heating belt is provided on the connecting pipeline from the urea solution outlet (9) to the urea solution addition port (8).

10. The urea hydrolysis reactor for efficiently recovering hydrophobic waste heat according to claim 1, characterized in that: The heat pipe heat exchanger (2) increases the heat exchange area by means of fins, which is larger than the heat exchange area, and is used to reduce the volume and weight of the heat exchanger.

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