Liquid ammonia gasification system and thermal power generation plant

Abstract

The liquid ammonia gasification system and the thermal power generation equipment disclosed by the application comprise, in sequence, a liquid ammonia supply assembly, a primary gasifier, a gas-liquid separation assembly, a secondary gasifier, an ammonia gas heating assembly and a boiler, the gas-liquid separation assembly is communicated with the ammonia gas heating assembly through a first connecting pipeline, the ammonia gas heating assembly is connected with a burner of the boiler, the boiler provides steam for the ammonia gas heating assembly, the ammonia gas heating assembly is connected with the secondary gasifier to provide a heating medium for the secondary gasifier, the secondary gasifier is connected with the boiler to deliver the drainage of the secondary gasifier to the boiler, and the heating medium of the primary gasifier is flue gas or wastewater of the boiler or seawater or river water. The liquid ammonia gasification system disclosed by the application can gasify liquid ammonia through the primary gasifier, separate gas and liquid through the gas-liquid separation assembly, further gasify the liquid ammonia that has not been gasified through the secondary gasifier, and heat, raise the temperature of and deliver the ammonia gas to the burner of the boiler through the ammonia gas heating assembly, so that a reliable ammonia gas source can be provided.

Description

Technical Field

[0001] This application relates to the field of liquid ammonia gasification technology for coal-fired boilers in power plants, and more specifically, to a liquid ammonia gasification system and thermal power generation equipment. Background Technology

[0002] Currently, coal-fired boilers use coal as fuel. To reduce carbon dioxide emissions, these boilers need to be modified to reduce coal consumption. Ammonia (NH3) is a zero-carbon fuel; its combustion products are mainly nitrogen and water, producing no carbon dioxide. Furthermore, ammonia is an excellent hydrogen storage medium with a high hydrogen storage density.

[0003] Ammonia-coal co-firing involves mixing ammonia and coal in a specific ratio and then burning the mixture in a power plant boiler. The combustion of ammonia partially replaces the combustion of coal, thereby reducing carbon dioxide emissions. In ammonia-coal co-firing technology, the gasification of liquid ammonia is a crucial step.

[0004] Therefore, how to provide a stable and reliable source of ammonia for coal-fired boiler burners has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of this application is to provide a liquid ammonia vaporization system to provide a stable and reliable source of ammonia for coal-fired boiler burners.

[0006] Another key aspect of this application is the disclosure of a thermal power generation device that includes the aforementioned liquid ammonia gasification system.

[0007] To achieve the above objectives, this application provides the following technical solution:

[0008] A liquid ammonia vaporization system includes a liquid ammonia supply component, a primary vaporizer, a gas-liquid separation component, a secondary vaporizer, an ammonia heating component, and a boiler connected in sequence. The gas-liquid separation component is connected to the ammonia heating component through a first connecting pipe.

[0009] The ammonia heating component is connected to the burner of the boiler, and the boiler provides steam to the ammonia heating component. The ammonia heating component is connected to the secondary gasifier to provide a heating medium for the secondary gasifier. The secondary gasifier is connected to the boiler to transport the wastewater from the secondary gasifier to the boiler.

[0010] The heating medium for the primary gasifier is flue gas, wastewater from the boiler, seawater, or river water.

[0011] Optionally, in the above-mentioned liquid ammonia vaporization system, a drainage pump is provided between the secondary vaporizer and the boiler.

[0012] Optionally, in the above-mentioned liquid ammonia vaporization system, the liquid ammonia supply component includes a liquid ammonia storage tank and / or a liquid ammonia supply pipeline.

[0013] Optionally, in the above-mentioned liquid ammonia vaporization system, a liquid ammonia transfer pump is provided between the liquid ammonia storage tank and the primary vaporizer.

[0014] Optionally, in the above-mentioned liquid ammonia vaporization system, the secondary vaporizer is connected to the ammonia heating component via a second connecting pipe;

[0015] The first connecting pipe is connected to the second connecting pipe; or, the first connecting pipe is connected to the ammonia heating component.

[0016] Optionally, in the above-mentioned liquid ammonia vaporization system, the ammonia heating component is equipped with a condensate recovery mechanism, which is connected to the secondary vaporizer via a condensate delivery pump.

[0017] Optionally, in the above-mentioned liquid ammonia vaporization system, the primary vaporizer includes one unit; or, the primary vaporizer includes multiple units connected in series; or, the primary vaporizer includes multiple units connected in parallel.

[0018] Optionally, in the above-mentioned liquid ammonia vaporization system, the secondary vaporizer includes one unit; or, the secondary vaporizer includes multiple units connected in series; or, the secondary vaporizer includes multiple units connected in parallel.

[0019] Optionally, in the above-mentioned liquid ammonia vaporization system, the ammonia heating component is equipped with a temperature measuring element, and a first regulating valve is installed on the third connecting pipe connecting the boiler and the ammonia heating component. The temperature measuring element is linked to the first regulating valve for control.

[0020] A thermal power generation device, including the aforementioned liquid ammonia gasification system.

[0021] As can be seen from the above scheme, the liquid ammonia gasification system disclosed in this application gasifies liquid ammonia through a primary gasifier, separates the liquid ammonia through a gas-liquid separation component, further gasifies the unvaporized liquid ammonia through a secondary gasifier, and then heats the ammonia through an ammonia heating component before sending it to the boiler burner for combustion, thus providing a reliable ammonia source for coal-fired boiler burners. The heating medium of the primary gasifier uses low-quality heat sources such as boiler exhaust gas, wastewater, seawater, or river water, which can reduce the system's energy consumption. The boiler provides steam to the ammonia heating component, and the steam is used to heat the relatively low-temperature ammonia. The saturated water formed after the steam is cooled enters the secondary vaporizer to heat the unvaporized liquid ammonia. Compared with directly vaporizing liquid ammonia with steam, this method can improve the problems of difficult vaporizer control and strong system lag. It can also improve the situation of large ammonia pressure fluctuations caused by directly vaporizing liquid ammonia with steam. The temperature control is more precise by heating the saturated water after steam condensation. The saturated water heats the unvaporized liquid ammonia to form drainage, which is then transported to the boiler for recycling. This can improve the current situation where steam directly provides heat through phase change to vaporize liquid ammonia and then is directly discharged after cooling through the condensate system, resulting in wasted steam energy. It can also reduce boiler water loss. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the liquid ammonia vaporization system disclosed in the embodiments of this application.

[0024] Among them, 1 is the liquid ammonia supply component, 101 is the liquid ammonia storage tank, 102 is the liquid ammonia supply pipeline, 2 is the primary vaporizer, 201 is the heating medium inlet pipeline, 202 is the heating medium outlet pipeline, 3 is the gas-liquid separation component, 301 is the first connecting pipeline, 4 is the secondary vaporizer, 401 is the second connecting pipeline, 5 is the ammonia heating component, 6 is the drainage pump, 7 is the boiler, and 701 is the third connecting pipeline. Detailed Implementation

[0025] Currently, the main methods of vaporizing liquid ammonia include electric heating vaporization, air heating vaporization, and steam heating vaporization, each with its own advantages and disadvantages.

[0026] Electric heating vaporization uses electricity to heat liquid ammonia to the vaporization temperature. The advantage of this method is that the vaporization process is easy to control and the vaporization rate can be precisely adjusted. However, this method consumes a lot of electricity and has a high cost.

[0027] Air-heated vaporization utilizes the heat of ambient air to vaporize liquid ammonia. During the vaporization process, the liquid ammonia absorbs ambient temperature, causing a decrease in the external temperature of the vaporizer. When the ambient temperature is low, this temperature decrease further affects the vaporization efficiency. For example, in regions with low winter temperatures, the efficiency of air-heated vaporization may decrease by 30%-40%, and incomplete vaporization may even occur.

[0028] For thermal power plants, steam heating gasification is currently the primary method. However, this method also presents some problems. Thermal power plants have high steam pressure and temperature, making the control of the gasifier difficult and resulting in significant system lag. This means that in actual operation, it is difficult to precisely control the gasification rate and temperature, easily leading to unstable gasification and affecting the effectiveness of ammonia-coal co-combustion. Furthermore, due to the difficulty in controlling the gasifier, operators may increase the steam output to ensure the gasification rate and temperature, resulting in excessive steam waste.

[0029] The core of this application is to disclose a liquid ammonia vaporization system that provides a stable and reliable source of ammonia for coal-fired boiler burners.

[0030] Another key aspect of this application is the disclosure of a thermal power generation device that includes the aforementioned liquid ammonia gasification system.

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] like Figure 1 As shown in the illustration, this application discloses a liquid ammonia vaporization system, comprising a liquid ammonia supply component 1, a primary vaporizer 2, a gas-liquid separation component 3, a secondary vaporizer 4, an ammonia heating component 5, and a boiler 7 connected in sequence. The gas-liquid separation component 3 is connected to the ammonia heating component 5 via a first connecting pipe 301, meaning that the ammonia gas separated by the gas-liquid separation component 3 can directly enter the ammonia heating component 5 for heating through the first connecting pipe 301. The ammonia heating component 5 is connected to the burner of the boiler 7, and the boiler 7 provides steam to the ammonia heating component 5. The ammonia heating component 5 is connected to the secondary vaporizer 4 to provide a heating medium for the secondary vaporizer 4. The secondary vaporizer 4 is connected to the boiler 7 to transport the wastewater from the secondary vaporizer 4 to the boiler 7. The heating medium for the primary vaporizer 2 is flue gas, wastewater from the boiler 7, seawater, river water, or other low-quality heat sources, providing heat for the primary vaporization of liquid ammonia.

[0033] Figure 1The arrows indicate the flow direction of the medium. Liquid ammonia supply component 1 provides liquid ammonia, which enters the primary vaporizer 2 for heating and vaporization, forming a mixture of unvaporized liquid ammonia and low-temperature ammonia gas. This mixture then enters the gas-liquid separation component 3 for gas-liquid separation. The low-temperature ammonia gas enters the ammonia heating component 5 through the first connecting pipe 301 for heating. The unvaporized liquid ammonia enters the secondary vaporizer 4 for further heating and vaporization. The resulting ammonia gas enters the ammonia heating component 5 for further heating, and after reaching the preset temperature, it enters the burner of the boiler 7 for combustion. The boiler 7 provides heating steam to the ammonia heating component 5. After the steam heats the ammonia gas, it is cooled to saturated water. The saturated water is sent to the secondary vaporizer 4 to heat the unvaporized liquid ammonia. The cooled wastewater is sent back to the boiler 7 for recycling.

[0034] The liquid ammonia vaporization system disclosed in this application vaporizes liquid ammonia through a primary vaporizer 2, separates the liquid ammonia through a gas-liquid separation component 3, further vaporizes the unvaporized liquid ammonia through a secondary vaporizer 4, and then heats the ammonia through an ammonia heating component 5 before being sent to the burner of a boiler 7 for combustion. This system provides a reliable ammonia source for coal-fired boiler burners. The heating medium for the primary vaporizer 2 uses low-quality heat sources such as flue gas, wastewater, seawater, or river water discharged from the boiler 7, which reduces the system's energy consumption. The boiler 7 provides steam to the ammonia heating component 5, which heats the relatively low-temperature ammonia. The saturated water formed after the steam is cooled enters the secondary vaporizer 4 to heat the unvaporized liquid ammonia. Compared with directly vaporizing liquid ammonia with steam, this method can improve the problems of difficult vaporizer control and strong system lag. It can also improve the situation of large ammonia pressure fluctuation caused by directly vaporizing liquid ammonia with steam. The temperature control is more precise by heating the saturated water after steam condensation. The saturated water heats the unvaporized liquid ammonia to form drainage, which is transported to boiler 7 for recycling. This can improve the current situation where steam directly provides heat through phase change to vaporize liquid ammonia and then is directly discharged after cooling through the condensate system, thus reducing the waste of steam energy and reducing boiler water loss.

[0035] Furthermore, such as Figure 1 As shown, the primary gasifier 2 is equipped with a heating medium inlet pipe 201 and a heating medium outlet pipe 202. Low-quality heat sources such as flue gas from boiler 7, wastewater from boiler 7, seawater, or river water enter the primary gasifier 2 through the heating medium inlet pipe 201 to heat the liquid ammonia. The specific heating medium can be selected according to the actual situation.

[0036] Furthermore, in order to transport the wastewater formed after heating liquid ammonia in the secondary gasifier 4 to the boiler 7, a wastewater conveying pump 6 is installed between the secondary gasifier 4 and the boiler 7. The wastewater conveying pump 6 provides power for transporting the wastewater to the boiler 7. Here, the wastewater refers to the water that has been cooled after being heated by saturated water with liquid ammonia.

[0037] Furthermore, such as Figure 1As shown, the liquid ammonia supply assembly 1 includes a liquid ammonia storage tank 101 and / or a liquid ammonia supply pipeline 102. The liquid ammonia supply assembly 1 shown in the figure includes a liquid ammonia storage tank 101 and a liquid ammonia supply pipeline 102. Here, the liquid ammonia supply pipeline 102 can refer to a pipeline that transports liquid ammonia from the plant. The liquid ammonia in the pipeline can be pressurized or additionally pressurized. The simultaneous installation of the liquid ammonia storage tank 101 and the liquid ammonia supply pipeline 102 provides a stable source of liquid ammonia. They can serve as backups for each other; if one fails, the other can act as a backup to supply liquid ammonia. In actual use, operators can flexibly choose to use the liquid ammonia transported from the liquid ammonia storage tank 101 or the liquid ammonia supply pipeline 102 according to actual needs.

[0038] Furthermore, in order to pressurize the liquid ammonia in the liquid ammonia storage tank 101, a liquid ammonia transfer pump is installed between the liquid ammonia storage tank 101 and the primary vaporizer 2.

[0039] Furthermore, such as Figure 1 As shown, the secondary vaporizer 4 is connected to the ammonia heating component 5 via a second connecting pipe 401, and the first connecting pipe 301 is connected to the second connecting pipe 401, or the first connecting pipe 301 is connected to the ammonia heating component 5. Here, the first connecting pipe 301 can be directly connected to the second connecting pipe 401. The ammonia gas separated by the gas-liquid separation component 3 is mixed with the ammonia gas vaporized by the secondary vaporizer 4 and then enters the ammonia heating component 5 for heating; or the ammonia gas separated by the gas-liquid separation component 3 and the ammonia gas vaporized by the secondary vaporizer 4 enter the ammonia heating component 5 for heating respectively. The specific method can be determined according to the actual situation.

[0040] Furthermore, the ammonia heating component 5 is equipped with a condensate recovery mechanism. The condensate recovery mechanism is connected to the secondary vaporizer 4 via a condensate delivery pump. Steam in the boiler 7 enters the ammonia heating component 5 to heat the low-temperature ammonia, which is then condensed into saturated water. The condensate delivery pump delivers the saturated water to the secondary vaporizer 4 to heat and vaporize the liquid ammonia that has not been vaporized after passing through the primary vaporizer 2. The resulting wastewater is then delivered to the boiler 7 for recycling.

[0041] Furthermore, the primary vaporizer 2 includes one; or, the primary vaporizer 2 includes multiple units connected in series; or, the primary vaporizer 2 includes multiple units connected in parallel. The specific number can be determined according to actual needs.

[0042] The secondary vaporizer 4 includes one; or, the secondary vaporizer 4 includes multiple units connected in series; or, the secondary vaporizer 4 includes multiple units connected in parallel. The specific number can be determined according to actual needs.

[0043] Furthermore, the ammonia heating component 5 is equipped with a temperature measuring element, and a first regulating valve is installed on the third connecting pipe 701 connecting the boiler 7 and the ammonia heating component 5. The temperature measuring element and the first regulating valve are linked for control, meaning the first regulating valve is configured to adjust its opening degree according to the temperature measurement value of the temperature measuring element. The temperature measuring element can measure the temperature of the ammonia after it has been heated by the ammonia heating component 5, and the first regulating valve adjusts its opening degree according to the temperature of the ammonia to ensure that the ammonia reaches the preset temperature. In addition, in some specific embodiments, the ammonia heating component 5 is equipped with a pressure measuring element to measure the pressure of the ammonia, and a second regulating valve is installed on the connecting pipe between the ammonia heating component 5 and the burner of the boiler 7 to regulate the pressure of the ammonia.

[0044] Furthermore, both the primary vaporizer 2 and the secondary vaporizer 4 are equipped with safety valves.

[0045] In addition, this application also discloses a thermal power generation device, including the above-mentioned liquid ammonia gasification system.

[0046] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0047] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0048] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A liquid ammonia vaporization system, characterized in that, It includes a liquid ammonia supply component (1), a primary vaporizer (2), a gas-liquid separation component (3), a secondary vaporizer (4), an ammonia heating component (5), and a boiler (7) connected in sequence. The gas-liquid separation component (3) is connected to the ammonia heating component (5) through a first connecting pipe (301). The ammonia heating component (5) is connected to the burner of the boiler (7), and the boiler (7) provides steam to the ammonia heating component (5). The ammonia heating component (5) is connected to the secondary gasifier (4) to provide a heating medium for the secondary gasifier (4). The secondary gasifier (4) is connected to the boiler (7) to transport the wastewater from the secondary gasifier (4) to the boiler (7). The heating medium of the primary gasifier (2) is flue gas or wastewater, seawater or river water from the boiler (7).

2. The liquid ammonia vaporization system as described in claim 1, characterized in that, A drainage pump (6) is provided between the secondary gasifier (4) and the boiler (7).

3. The liquid ammonia vaporization system as described in claim 1, characterized in that, The liquid ammonia supply assembly (1) includes a liquid ammonia storage tank (101) and / or a liquid ammonia supply pipeline (102).

4. The liquid ammonia vaporization system as described in claim 3, characterized in that, A liquid ammonia transfer pump is provided between the liquid ammonia storage tank (101) and the primary vaporizer (2).

5. The liquid ammonia vaporization system as described in claim 1, characterized in that, The secondary vaporizer (4) is connected to the ammonia heating assembly (5) via a second connecting pipe (401); The first connecting pipe (301) is connected to the second connecting pipe (401); or, the first connecting pipe (301) is connected to the ammonia heating component (5).

6. The liquid ammonia vaporization system as described in claim 1, characterized in that, The ammonia heating component (5) is equipped with a condensate recovery mechanism, which is connected to the secondary vaporizer (4) via a condensate delivery pump.

7. The liquid ammonia vaporization system as described in claim 1, characterized in that, The primary vaporizer (2) comprises one; or, the primary vaporizer (2) comprises multiple units connected in series; or, the primary vaporizer (2) comprises multiple units connected in parallel.

8. The liquid ammonia vaporization system as described in claim 1, characterized in that, The secondary vaporizer (4) comprises one; or, the secondary vaporizer (4) comprises multiple units connected in series; or, the secondary vaporizer (4) comprises multiple units connected in parallel.

9. The liquid ammonia vaporization system as described in claim 1, characterized in that, The ammonia heating component (5) is equipped with a temperature measuring element, and a first regulating valve is provided on the third connecting pipe (701) connecting the boiler (7) and the ammonia heating component (5). The temperature measuring element is linked to the first regulating valve for control.

10. A thermal power generation device, characterized in that, Includes the liquid ammonia vaporization system as described in any one of claims 1-9.

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