Liquid ammonia evaporation system utilizing flue gas waste heat
By setting up a liquid ammonia evaporator and an ammonia superheater on the flue of the thermal power generation device, the liquid ammonia is evaporated by the waste heat of the flue gas and further overheated it, the problem of unused flue gas heat is solved, and efficient energy recovery and flue gas are achieved Reduced moisture content.
Patent Information
- Application Number
- CN202420391694.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-29
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-02-28
AI Technical Summary
The thermal energy carried by flue gas in thermal power plants is not utilized, and the existing liquid ammonia evaporation process requires a large amount of energy, resulting in waste of energy.
A liquid ammonia evaporator and an ammonia superheater are installed on the flue of the thermal power generation device. The liquid ammonia is evaporated by the waste heat of the flue gas, and further overheats through the ammonia superheater to make full use of the flue gas waste heat.
It reduces the loss of steam or electricity by liquid ammonia evaporation, effectively recovers flue gas waste heat, reduces energy consumption, and sets a liquid ammonia evaporator at the inlet of the chimney to reduce the water content of the flue gas, which has the effect of whitening and water collection.
Smart Images
Figure CN222266132U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of energy saving and low carbon in thermal power plants, and relates to a liquid ammonia evaporation system utilizing flue gas waste heat. Background Art
[0002] Thermal power generating units are large and have many machines, which roughly cause energy waste in two aspects: on the one hand, the electricity used in the factory is divided into productive electricity and non-productive electricity. How to reduce energy waste is a direct and effective way to save energy and reduce carbon. On the other hand, the net heat rate loss of the unit is divided into controllable and uncontrollable losses. If the heat rate loss cannot be controlled, it will affect the power generation efficiency, causing greater energy loss and waste. Ammonia combustion in thermal power plants is an effective means of reducing carbon, but in order to facilitate transportation, most of the ammonia in thermal power plants is in the form of liquid ammonia. Liquid ammonia needs to be evaporated and gasified before entering the boiler for combustion. The existing liquid ammonia evaporation generally uses steam as the heat source, and some liquid ammonia evaporation uses electricity as the heat source. Whether steam or electricity is used, it is a major loss of energy, especially after the amount of ammonia increases, the energy loss will be higher. The large amount of heat stored in the flue gas during the power generation process cannot be used, which also causes a certain amount of energy waste. Utility Model Content
[0003] The utility model aims to solve the technical problems in the prior art that the heat energy carried by flue gas in thermal power generation is not utilized and a large amount of energy is required to heat ammonia, and to provide a liquid ammonia evaporation system utilizing the waste heat of flue gas.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] In a first aspect, the utility model provides a liquid ammonia evaporation system utilizing waste heat of flue gas, comprising a liquid ammonia evaporator arranged on a flue of a thermal power generation device; the inlet of the liquid ammonia evaporator is connected to a liquid ammonia tank or a liquid ammonia pump; the outlet of the liquid ammonia evaporator is connected to a pre-furnace ammonia blending system.
[0006] The utility model is further improved in that:
[0007] The outlet of the liquid ammonia evaporator is connected to an ammonia superheater arranged on the flue of the thermal power generation device; the outlet of the ammonia superheater is connected to a pre-furnace ammonia blending system.
[0008] The ammonia superheater comprises an ammonia superheater upper header and an ammonia superheater lower header which are connected through an ammonia superheater heat exchange pipe.
[0009] The ammonia superheater is replaced by a high-level buffer tank; the outlet of the liquid ammonia evaporator is connected to the inlet of the high-level buffer tank; the top outlet of the high-level buffer tank is connected to the pre-furnace ammonia doping system; the bottom outlet of the high-level buffer tank is connected to the inlet of the liquid ammonia evaporator.
[0010] The ammonia pipeline connected to the liquid ammonia evaporator is provided with a safety valve, a temperature transmitter and a pressure transmitter; the ammonia pipeline connected to the ammonia superheater is provided with a safety valve, a temperature transmitter and a pressure transmitter; the ammonia pipeline connected to the high-level buffer tank is provided with a safety valve, a temperature transmitter and a pressure transmitter.
[0011] The thermal power generation device comprises a boiler air preheater, a dust collector, an induced draft fan, a desulfurization tower and a chimney which are sequentially connected along the flow direction of the flue gas; the liquid ammonia evaporator is arranged on the flue between the desulfurization tower and the chimney.
[0012] The ammonia superheater is arranged on the flue between the dust collector and the induced draft fan.
[0013] The bottom of the rear flue of the liquid ammonia evaporator along the flue gas flow direction is provided with a slope, and a water collecting pipe is provided at the lower end of the slope.
[0014] The liquid ammonia evaporator comprises an upper header and a lower header of the liquid ammonia evaporator which are connected via a downcomer; a liquid ammonia evaporator heat exchange tube is arranged between the upper header and the lower header of the liquid ammonia evaporator.
[0015] The pipeline diameter of the upper header of the liquid ammonia evaporator is larger than the pipeline diameter of the lower header of the liquid ammonia evaporator; the pipeline of the upper header of the liquid ammonia evaporator is inclined, and the lower end is connected with a downcomer.
[0016] Compared with the prior art, the utility model has the following beneficial effects:
[0017] The utility model discloses a liquid ammonia evaporation system utilizing flue gas waste heat. An ammonia evaporator is arranged on the flue of a thermal power generation device, and liquid ammonia is evaporated using flue gas waste heat as a heat source, thereby recovering flue gas waste heat and reducing the loss of steam or electric energy caused by the evaporation of liquid ammonia.
[0018] Furthermore, installing a liquid ammonia evaporator at the chimney inlet can effectively reduce the water content in the flue gas, and simultaneously have the effects of eliminating white and collecting water.
[0019] Furthermore, an ammonia superheater is provided on the flue of the thermal power generation device to further superheat the ammonia obtained in the liquid ammonia evaporator and make full use of the waste heat of the flue gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.
[0021] Figure 1 This is a structural diagram of a liquid ammonia evaporation system utilizing flue gas waste heat in Example 1 of the utility model;
[0022] Figure 2 This is a structural diagram of the liquid ammonia evaporator in Embodiment 1 and Embodiment 2 of the present utility model;
[0023] Figure 3 This is a structural diagram of the ammonia superheater in Embodiment 1 and Embodiment 2 of the present utility model;
[0024] Figure 4 This is a structural diagram of a liquid ammonia evaporation system utilizing flue gas waste heat in Example 2 of the present utility model.
[0025] Among them: 1-liquid ammonia evaporator; 101-liquid ammonia evaporator heat exchange tube; 102-liquid ammonia evaporator upper header; 103-liquid ammonia evaporator lower header; 104-liquid ammonia evaporator downcomer; 2-ammonia superheater; 201-ammonia superheater heat exchange tube; 202-ammonia superheater upper header; 203-ammonia superheater lower header; 3-boiler air preheater; 4-dust collector; 5-flue; 6-induced draft fan; 7-desulfurization tower; 8-chimney; 9-collecting pipe; 10-high-level buffer tank; 11-ammonia pipeline. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0029] In the description of the embodiments of the present utility model, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use, it is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0030] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0031] In the description of the embodiments of the present utility model, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0032] The utility model is further described in detail below with reference to the accompanying drawings:
[0033] Embodiment 1
[0034] See also Figure 1The embodiment of the present invention discloses a liquid ammonia evaporation system using flue gas waste heat, comprising a liquid ammonia evaporator 1 arranged on the flue of a thermal power generation device; the thermal power generation device comprises a boiler air preheater 3, a dust collector 4, an induced draft fan 6, a desulfurization tower 7 and a chimney 8 connected in sequence along the flue gas flow direction; the liquid ammonia evaporator 1 is arranged on the flue between the desulfurization tower 7 and the chimney 8, and a slope is arranged at the bottom of the flue behind the liquid ammonia evaporator 1 along the flue gas flow direction, and a water collecting pipe 9 is arranged at the lower end of the slope, and the slope is 2%. The inlet of the liquid ammonia evaporator 1 is connected to a liquid ammonia tank or a liquid ammonia pump; the outlet of the liquid ammonia evaporator 1 is connected to an ammonia superheater 2 arranged on the flue of the thermal power generation device, and the ammonia superheater 2 is arranged on the flue between the dust collector 4 and the induced draft fan 6; the outlet of the ammonia superheater 2 is connected to a pre-furnace ammonia mixing system. The ammonia pipeline connected to the liquid ammonia evaporator 1 is provided with a safety valve, a temperature transmitter and a pressure transmitter; the ammonia pipeline connected to the ammonia superheater 2 is provided with a safety valve, a temperature transmitter and a pressure transmitter.
[0035] See also Figure 2 The liquid ammonia evaporator 1 comprises an upper header 102 and a lower header 103 of the liquid ammonia evaporator connected by a downcomer 104; a liquid ammonia evaporator heat exchange tube 101 is arranged between the upper header 102 and the lower header 103 of the liquid ammonia evaporator. The pipe diameter of the upper header 102 of the liquid ammonia evaporator is larger than the pipe diameter of the lower header 103 of the liquid ammonia evaporator; the pipe of the upper header 102 of the liquid ammonia evaporator is arranged obliquely, and the lower end is connected to the downcomer 104.
[0036] See also Figure 3 The ammonia superheater 2 includes an ammonia superheater upper header 202 and an ammonia superheater lower header 203 which are connected through an ammonia superheater heat exchange pipe 201.
[0037] Working process of embodiment 1:
[0038] The liquid ammonia evaporator 1 is arranged on the outlet flue of the desulfurization tower 7. The liquid ammonia from the ammonia tank or the liquid ammonia pump enters the liquid ammonia evaporator 1 from the lower header 103 of the liquid ammonia evaporator. After heat exchange through the liquid ammonia evaporator 1, most of the liquid ammonia is evaporated, and a small amount of unevaporated liquid ammonia returns to the inlet of the lower header 103 of the liquid ammonia evaporator from the liquid ammonia evaporator downcomer 104 and passes through the liquid ammonia evaporator 1 again. The upper header 102 of the liquid ammonia evaporator adopts a thickened structure and has a certain slope to ensure that the unvaporized liquid ammonia can be separated to a certain extent. The ammonia coming out of the liquid ammonia evaporator 1 enters the ammonia superheater 2 arranged at the inlet of the induced draft fan 6 or other upstream flue, and the ammonia is further superheated in the ammonia superheater 2. After the superheating is completed, the ammonia is passed to the ammonia mixing system in front of the furnace.
[0039] The utility model discloses a liquid ammonia evaporation system utilizing flue gas waste heat. An ammonia evaporator is arranged on the flue of a thermal power generation device, and liquid ammonia is evaporated using flue gas waste heat as a heat source, thereby recovering flue gas waste heat and reducing the loss of steam or electric energy caused by liquid ammonia evaporation. The liquid ammonia evaporator is arranged at the chimney inlet to effectively reduce the water content in the flue gas, and simultaneously has the effects of eliminating white and collecting water. An ammonia superheater is also arranged on the flue of the thermal power generation device to further superheat the ammonia obtained in the liquid ammonia evaporator, thereby fully utilizing the flue gas waste heat.
[0040] Embodiment 2
[0041] See also Figure 4 The embodiment of the present invention discloses a liquid ammonia evaporation system using flue gas waste heat, comprising a liquid ammonia evaporator 1 arranged on the flue of a thermal power generation device; the thermal power generation device comprises a boiler air preheater 3, a dust collector 4, an induced draft fan 6, a desulfurization tower 7 and a chimney 8 connected in sequence along the flue gas flow direction; the liquid ammonia evaporator 1 is arranged on the flue between the desulfurization tower 7 and the chimney 8, and a slope is arranged at the bottom of the flue behind the liquid ammonia evaporator 1 along the flue gas flow direction, and a water collecting pipe 9 is arranged at the lower end of the slope, and the slope is 2%. The inlet of the liquid ammonia evaporator 1 is connected to a liquid ammonia tank or a liquid ammonia pump; the outlet of the liquid ammonia evaporator 1 is connected to the inlet of a high-level buffer tank 10; the top outlet of the high-level buffer tank 10 is connected to a pre-furnace ammonia mixing system; the bottom outlet of the high-level buffer tank 10 is connected to the inlet of the liquid ammonia evaporator 1. The ammonia pipeline connected to the liquid ammonia evaporator 1 is provided with a safety valve, a temperature transmitter and a pressure transmitter; the ammonia pipeline connected to the high-level buffer tank 10 is provided with a safety valve, a temperature transmitter and a pressure transmitter;
[0042] See also Figure 2 The liquid ammonia evaporator 1 comprises an upper header 102 and a lower header 103 of the liquid ammonia evaporator connected by a downcomer 104; a liquid ammonia evaporator heat exchange tube 101 is arranged between the upper header 102 and the lower header 103 of the liquid ammonia evaporator. The pipe diameter of the upper header 102 of the liquid ammonia evaporator is larger than the pipe diameter of the lower header 103 of the liquid ammonia evaporator; the pipe of the upper header 102 of the liquid ammonia evaporator is arranged obliquely, and the lower end is connected to the downcomer 104.
[0043] Working process of embodiment 2:
[0044] The liquid ammonia evaporator 1 is arranged on the outlet flue of the desulfurization tower 7. The liquid ammonia from the ammonia tank or the liquid ammonia pump enters the liquid ammonia evaporator 1 from the lower header 103 of the liquid ammonia evaporator. Most of the liquid ammonia is evaporated after heat exchange through the liquid ammonia evaporator 1. After evaporation, the liquid ammonia becomes ammonia gas and enters the high buffer tank 10 from the middle of the high buffer tank 10. A small amount of liquid ammonia that has not been evaporated flows back to the inlet of the lower header 103 of the liquid ammonia evaporator through the bottom pipeline of the high buffer tank 10 and passes through the liquid ammonia evaporator 1 again. The ammonia gas at the top outlet of the high buffer tank 10 leads to the ammonia mixing system in front of the furnace. The bottom flue of the liquid ammonia evaporator 1 is set with a certain drainage slope, which slopes towards the water collecting pipe to collect condensed water in the flue gas.
[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A liquid ammonia evaporation system utilizing flue gas waste heat, characterized in that: It comprises a liquid ammonia evaporator (1) arranged on the flue of a thermal power generation device; the inlet of the liquid ammonia evaporator (1) is connected to a liquid ammonia tank or a liquid ammonia pump; the outlet of the liquid ammonia evaporator (1) is connected to a pre-furnace ammonia blending system.
2. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 1, characterized in that: The outlet of the liquid ammonia evaporator (1) is connected to an ammonia superheater (2) arranged on the flue of a thermal power generation device; and the outlet of the ammonia superheater (2) is connected to a pre-furnace ammonia blending system.
3. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 2, characterized in that: The ammonia superheater (2) comprises an ammonia superheater upper header (202) and an ammonia superheater lower header (203) which are connected via an ammonia superheater heat exchange pipe (201).
4. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 2, characterized in that: The ammonia superheater (2) is replaced by a high-position buffer tank (10); the outlet of the liquid ammonia evaporator (1) is connected to the inlet of the high-position buffer tank (10); the top outlet of the high-position buffer tank (10) is connected to a pre-furnace ammonia blending system; and the bottom outlet of the high-position buffer tank (10) is connected to the inlet of the liquid ammonia evaporator (1).
5. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 4, characterized in that: The ammonia pipeline connected to the liquid ammonia evaporator (1) is provided with a safety valve, a temperature transmitter and a pressure transmitter; the ammonia pipeline connected to the ammonia superheater (2) is provided with a safety valve, a temperature transmitter and a pressure transmitter; the ammonia pipeline connected to the high-level buffer tank (10) is provided with a safety valve, a temperature transmitter and a pressure transmitter.
6. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 4, characterized in that: The thermal power generation device comprises a boiler air preheater (3), a dust collector (4), an induced draft fan (6), a desulfurization tower (7) and a chimney (8) which are sequentially connected along the flow direction of the flue gas; the liquid ammonia evaporator (1) is arranged on the flue between the desulfurization tower (7) and the chimney (8).
7. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 6, characterized in that: The ammonia superheater (2) is arranged on the flue between the dust collector (4) and the induced draft fan (6).
8. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 1, characterized in that: The bottom of the rear flue of the liquid ammonia evaporator (1) along the flue gas flow direction is provided with a slope, and a water collecting pipe (9) is provided at the lower end of the slope.
9. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 1, characterized in that: The liquid ammonia evaporator (1) comprises an upper header (102) and a lower header (103) of the liquid ammonia evaporator which are connected via a downcomer (104); a liquid ammonia evaporator heat exchange tube (101) is arranged between the upper header (102) and the lower header (103) of the liquid ammonia evaporator.
10. The liquid ammonia evaporation system utilizing flue gas waste heat according to claim 9, characterized in that: The pipe diameter of the upper header (102) of the liquid ammonia evaporator is larger than the pipe diameter of the lower header (103) of the liquid ammonia evaporator; the pipe of the upper header (102) of the liquid ammonia evaporator is arranged obliquely, and a downcomer (104) is connected to the lower end.