Device for rapidly releasing and utilizing residual ammonia in liquid ammonia pipeline of thermal power plant
By installing a small water bath heater in the liquid ammonia pipeline of the thermal power plant, the residual ammonia is heated by circulating water, and rapid evaporation and combustion are achieved, which solves the problem of incomplete discharge of residual ammonia in the liquid ammonia pipeline and insufficient utilization, and improves safety and efficiency.
Patent Information
- Application Number
- CN202422227687.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-09-11
AI Technical Summary
In the prior art, when liquid ammonia pipelines are deactivated or repaired, it is difficult to quickly release residual ammonia, resulting in safety hazards such as overpressure of the pipeline, condensation corrosion, etc., and traditional methods have problems such as incomplete discharge and exhaust gas wastewater and insufficient utilization of residual ammonia.
A device for rapid discharge and utilization of residual ammonia in liquid ammonia pipelines in thermal power plants is designed. By installing a small water bath heater at the low points of denitrification and admixture of liquid ammonia pipelines, the residual ammonia is heated by circulating water in the power plant, so that it can quickly evaporate and enter the boiler furnace to burn, achieving rapid discharge and safe utilization.
The rapid discharge and safe utilization of residual ammonia in liquid ammonia pipelines is achieved, avoiding the problems of waste gas and wastewater discharge and pipeline condensation corrosion in traditional methods. At the same time, the calorific value of ammonia is used to generate electricity, improving overall efficiency and safety.
Smart Images
Figure CN223036203U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of liquid ammonia combustion, and particularly relates to a device for quickly discharging and utilizing residual ammonia in a liquid ammonia pipeline of a thermal power plant. Background Technique
[0002] Liquid ammonia is usually used as a reducing agent for flue gas denitrification in thermal power plants. Recently, it has also gradually been used as a fuel to be introduced into a boiler for combustion power generation to reduce carbon dioxide emissions from thermal power plants. When the liquid ammonia pipeline is out of service or under maintenance, the residual liquid ammonia in the pipeline needs to be quickly discharged to prevent the residual liquid ammonia from absorbing heat and evaporating and expanding in the dead-end pipe, causing the pipeline to be overpressurized, and leading to dew condensation and corrosion on the outer wall of the pipeline, threatening the safety of the pipeline and equipment. At present, the methods of water flushing or nitrogen replacement and evacuation are mostly used to discharge the residual ammonia in the pipe to below the safe pressure or evacuate it. For the liquid ammonia pipeline used for co-firing, the method of slowly introducing the residual ammonia into the furnace for combustion can be used to relieve the pressure. The water flushing and replacement method has problems of ammonia water corrosion and difficult wastewater treatment. The nitrogen replacement method faces problems of low replacement efficiency, incomplete liquid ammonia discharge, and non-recovery and utilization of residual ammonia. The method of slow co-firing also has the problem that the self-evaporation rate of liquid ammonia is slow and it is difficult to discharge it completely in a short time. Therefore, a new device is needed to achieve the quick discharge and utilization of residual ammonia in the liquid ammonia pipeline of a thermal power plant. Summary of the Invention
[0003] To solve the above technical problems, the utility model provides a device for quickly discharging and utilizing residual ammonia in a liquid ammonia pipeline of a thermal power plant, which can quickly discharge the residual ammonia in the liquid ammonia pipelines for denitrification and co-firing in the power plant to below the safe pressure or evacuate it, and realize safe utilization, facilitating the maintenance and upkeep of the liquid ammonia pipeline after it is out of service. The utility model connects the end of the denitrification liquid ammonia pipeline to the co-firing liquid ammonia pipeline and sets one or more small water bath heaters at the low points of the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline respectively, and uses the waste heat of the return water of the power plant circulating water to heat the residual ammonia in the pipeline after it is out of service, so that it quickly evaporates and enters the boiler furnace for combustion. This can not only reduce the waste gas and wastewater emissions during the discharge of residual ammonia, speed up the discharge speed of residual ammonia, but also utilize the calorific value of ammonia itself for combustion power generation.
[0004] To achieve the above object, the utility model adopts the following technical scheme:
[0005] A device for quickly discharging and utilizing residual ammonia in liquid ammonia pipelines of thermal power plants, comprising a denitrification liquid ammonia pipeline, a co-firing liquid ammonia pipeline, a small water bath heater, a nitrogen purging port, a pressure gauge, and an ammonia concentration meter; the small water bath heater is respectively installed at the low points of the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline, and the low points are the places where residual ammonia accumulates; the end of the denitrification liquid ammonia pipeline is connected to the end of the co-firing liquid ammonia pipeline through a tee, and the end of the co-firing liquid ammonia pipeline is connected to the boiler furnace to realize the direct combustion of liquid ammonia or residual ammonia steam; pressure gauges are installed on both the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline to monitor the change of the pressure in the pipeline; ammonia concentration meters are installed on both the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline; nitrogen purging ports are installed on both the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline.
[0006] Further, the low points of the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline respectively include one or more.
[0007] Further, the heat source of the small water bath heater adopts the return water of the power plant circulating water, and the residual heat of the circulating water is used to accelerate the evaporation of the residual ammonia in the pipeline into the furnace for combustion until the pressure gauge shows that the pressure is lower than 0.1 MPa and then it turns to the maintenance state.
[0008] Further, nitrogen purging is carried out at the nitrogen purging port, and the tail gas after purging is directly introduced into the boiler furnace for co-firing. Until the concentrations shown by the ammonia concentration meters installed on both the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline meet the specification requirements, stop purging and isolate the pipeline for maintenance.
[0009] The utility model has the following beneficial effects:
[0010] Aiming at the situation that there is no heating heat source after the denitrification liquid ammonia pipeline and the co-firing liquid ammonia pipeline are out of use, the residual heat of the power plant circulating water and the small water bath heater are used to realize the rapid evaporation of the residual ammonia in the pipeline, and the ammonia is introduced into the furnace for co-firing through the liquid ammonia co-firing pipeline, solving the problems of a large amount of ammonia water discharge and corrosion caused by the traditional water flushing method, as well as the problems of incomplete residual ammonia removal, long time consumption, and dew condensation and corrosion of the pipe wall in the direct nitrogen replacement method and the slow co-firing method. The whole discharging process of the utility model has no waste gas and waste water discharge, short time consumption, no dew condensation on the pipeline, and realizes the efficient and safe utilization of the ammonia calorific value. Description of the Drawings
[0011] Figure 1 is a schematic diagram of a device for quickly discharging and utilizing residual ammonia in liquid ammonia pipelines of thermal power plants of the utility model;
[0012] Among them, the reference numerals are: 1 is the denitrification liquid ammonia pipeline, 2 is the co-firing liquid ammonia pipeline, 3 is the small water bath heater, 4 is the nitrogen purging port, 5 is the boiler furnace, 6 is the pressure gauge, and 7 is the ammonia concentration meter. Detailed Embodiments
[0013] Embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. The embodiments described in the drawings are merely exemplary and are only used to explain this utility model, and should not be construed as limiting the present utility model.
[0014] The present utility model provides a device for quickly discharging and utilizing the remaining ammonia in the liquid ammonia pipeline of a thermal power plant. As Figure 1 shown, it mainly includes a denitration liquid ammonia pipeline 1, a blending combustion liquid ammonia pipeline 2, a small water bath heater 3, a nitrogen purging port 4, a pressure gauge 6, and an ammonia concentration meter 7.
[0015] The small water bath heater 3 is respectively installed at the low points of the denitration liquid ammonia pipeline 1 and the blending combustion liquid ammonia pipeline 2. The low points refer to the places where the pipeline position is relatively low and the remaining ammonia accumulates. The low points of the denitration liquid ammonia pipeline 1 and the blending combustion liquid ammonia pipeline 2 respectively include one or more, that is, there may be more than one low point in the pipeline.
[0016] The heat source of the small water bath heater 3 adopts the return water of the power plant circulating water, and uses the waste heat of the circulating water to accelerate the evaporation of the remaining ammonia in the pipeline.
[0017] Preferably, two of the small water bath heaters 3 are respectively arranged on the denitration liquid ammonia pipeline 1 and the blending combustion liquid ammonia pipeline 2.
[0018] The end of the denitration liquid ammonia pipeline 1 is connected to the end of the blending combustion liquid ammonia pipeline 2 through a tee. This tee is closed during normal operation and opened when the denitration liquid ammonia pipeline is out of service or under maintenance; the end of the blending combustion liquid ammonia pipeline 2 is connected to the boiler furnace 5 to realize the direct combustion of liquid ammonia or remaining ammonia steam.
[0019] Pressure gauges 6 are installed on both the denitration liquid ammonia pipeline 1 and the blending combustion liquid ammonia pipeline 2 to monitor the change of the pressure inside the pipeline. After the remaining ammonia in the pipeline that is not under maintenance after being out of service is discharged, the pressure inside the pipeline should be lower than 0.1 MPa before entering the maintenance state.
[0020] For the liquid ammonia pipeline that needs to be maintained after being out of service, after the remaining ammonia pressure is discharged to 0.1 MPa, nitrogen purging is carried out through the nitrogen purging port 4. The tail gas after purging is directly introduced into the boiler furnace 5 for blending combustion until the concentration shown by the ammonia concentration meters 7 installed on both the denitration liquid ammonia pipeline 1 and the blending combustion liquid ammonia pipeline 2 meets the specification requirements, then the purging is stopped and the pipeline is isolated for maintenance.
[0021] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A device for rapidly releasing and utilizing excess ammonia in a liquid ammonia pipeline of a thermal power plant, characterized in that: It includes a denitrification liquid ammonia pipeline, a blended liquid ammonia pipeline, a small water bath heater, a nitrogen purge port, a pressure gauge, and an ammonia concentration meter; the small water bath heater is respectively installed at the low points of the denitrification liquid ammonia pipeline and the blended liquid ammonia pipeline, and the low points are the places where the residual ammonia is collected; the end of the denitrification liquid ammonia pipeline is connected to the end of the blended liquid ammonia pipeline through a tee, and the end of the blended liquid ammonia pipeline is connected to the boiler furnace to realize direct combustion of liquid ammonia or residual ammonia vapor; pressure gauges are installed on the denitrification liquid ammonia pipeline and the blended liquid ammonia pipeline to monitor changes in pressure in the pipes; ammonia concentration meters are installed on the denitrification liquid ammonia pipeline and the blended liquid ammonia pipeline; nitrogen purge ports are installed on the denitrification liquid ammonia pipeline and the blended liquid ammonia pipeline.
2. The device for rapidly releasing and utilizing excess ammonia in a liquid ammonia pipeline of a thermal power plant according to claim 1, characterized in that: The denitrification liquid ammonia pipeline and the blended ammonia liquid ammonia pipeline each include one or more low points.
3. The device for rapidly releasing and utilizing excess ammonia in a liquid ammonia pipeline of a thermal power plant according to claim 1, characterized in that: The heat source of the small water bath heater adopts the circulating water return from the power plant, and the waste heat of the circulating water is used to accelerate the evaporation of the residual ammonia in the tube and enter the furnace for combustion until the pressure gauge shows that the pressure is lower than 0.1MPa and then enters the maintenance state.
4. The device for rapidly releasing and utilizing excess ammonia in a liquid ammonia pipeline of a thermal power plant according to claim 1, characterized in that: The nitrogen purge port is used for nitrogen purge, and the tail gas after purge is directly introduced into the boiler furnace for co-combustion, until the concentration displayed by the ammonia concentration meters installed on the denitrification liquid ammonia pipeline and the co-combustion liquid ammonia pipeline meets the specification requirements, then the purge is stopped and the pipeline is isolated for maintenance.