CN213119582U

CN213119582U - Boiler continuous exhaust steam screw type heat pump supercharging recovery system

Info

Publication number: CN213119582U
Application number: CN202021842908.4U
Authority: CN
Inventors: 吴伟; 张冲; 武超
Original assignee: Csic Shanghai New Energy Co ltd
Current assignee: Csic Shanghai New Energy Co ltd
Priority date: 2020-08-29
Filing date: 2020-08-29
Publication date: 2021-05-04
Anticipated expiration: 2030-08-29

Abstract

A boiler continuous exhaust steam screw type heat pump supercharging recovery system belongs to the technical field of waste heat utilization, and comprises a continuous exhaust flash tank, a steam-water separator, a heat exchanger, a screw heat pump, an electric regulating valve, a safety valve, a heat exchange pipeline, a boiler continuous exhaust pipeline, a recovery pipeline, an available steam pipeline and a supercharging and warming pipeline; the inlet of the pressurizing and heating pipeline is connected with the outlet at the upper end of the parallel row flash tank, and the outlet of the pressurizing and heating pipeline is respectively connected with the inlets of the first recovery pipeline and the steam turbine steam supplementing pipeline; the steam-water separator, the heat exchanger and the screw heat pump are sequentially connected in series on the supercharging and warming pipeline along the flow direction of the working medium; the inlet of the first heat exchange pipeline is connected with the boiler water connecting and discharging pipeline, and the outlet of the first heat exchange pipeline is connected with the heat exchanger; the inlet of the second heat exchange pipeline is connected with the heat exchanger, and the outlet of the second heat exchange pipeline is connected with the inlet at the lower end of the parallel row flash tank. The utility model realizes the conversion of medium and high parameters, and solves the waste of heat energy and water resource caused by directly discharging exhaust steam; the problems of low efficiency of direct organic Rankine cycle power generation and difficulty in recycling equipment cost are solved.

Description

Boiler continuous exhaust steam screw type heat pump supercharging recovery system

Technical Field

The utility model relates to a boiler waste heat recovery system in waste heat recovery technical field, the characteristic is a boiler that can realize the well high parameter and change even exhaust steam screw heat pump pressure boost recovery system that arranges.

Background

In the electric power trade, the continuous blowdown water of boiler steam pocket, generally behind the flash tank that even arranges, the comdenstion water gets into even the exhaust box and arranges outward or retrieve, and the exhaust steam is direct outer arranging, leads to a large amount of heat waste, better power plant that the environmental protection was done, and flash tank exhaust steam that even arranges is further retrieved through the oxygen-eliminating device, perhaps retrieves through getting into the flash tank of surely arranging and directly arranges afterwards, leads to the heat waste of exhaust steam, water waste. In order to improve the economy of power plants, some power plants propose continuous exhaust steam to be recycled for direct organic Rankine cycle power generation or expansion power generation. And the organic Rankine cycle has low power generation efficiency, direct screw expansion power generation and low exhaust steam taste, so that the power generation amount is low, the power generation economy is low, the cost is difficult to recover, and the application scene is limited.

Disclosure of Invention

The utility model provides a boiler continuous exhaust steam screw type heat pump supercharging recovery system aiming at the defects of the prior art, which can solve the problem that the exhaust steam water resource and the exhaust steam heat resource of the traditional boiler continuous exhaust flash tank are not recycled and the problem that the recovery economy of the traditional boiler exhaust steam waste heat is low in organic Rankine or direct expansion power generation; the problem that the boiler continuously exhausted steam has low parameters and can not directly participate in power generation of the steam turbine due to the fact that the boiler continuously exhausted steam needs to be recovered to the deaerator and the problem that a proper steam compressor is not available under the conditions of high temperature rise and large outlet pressure can be solved.

The utility model is realized by the following technical proposal, the utility model comprises a parallel arrangement flash tank, a steam-water separator, a heat exchanger, a screw heat pump, an electric control valve, a safety valve, a first heat exchange pipeline, a second heat exchange pipeline, a boiler continuous drainage pipeline, a first recovery pipeline, an available steam pipeline, a second recovery pipeline, a steam turbine steam supplementing pipeline, a pressure and temperature increasing pipeline and a water tank; the outlet of the boiler continuous drainage pipeline is connected with the inlet at the upper end of the continuous drainage flash tank; the inlet of the pressurizing and heating pipeline is connected with the outlet at the upper end of the parallel row flash tank, and the outlet of the pressurizing and heating pipeline is respectively connected with the inlets of the first recovery pipeline and the steam turbine steam supplementing pipeline; the steam-water separator, the heat exchanger and the screw heat pump are sequentially connected in series on the supercharging and warming pipeline along the flow direction of the working medium; the inlet of the first heat exchange pipeline is connected with the boiler water connecting and discharging pipeline, and the outlet of the first heat exchange pipeline is connected with the heat exchanger; the inlet of the second heat exchange pipeline is connected with the heat exchanger, and the outlet of the second heat exchange pipeline is connected with the inlet at the lower end of the parallel row flash tank; an inlet of the second recovery pipeline is connected with an outlet at the lower end of the steam-water separator, and an outlet of the second recovery pipeline is connected with a water tank at the lower end of the parallel-row flash tank; the outlet of the first recovery pipeline is connected with the second heat exchange pipeline, and the outlet of the available steam pipeline is connected with the steam supplementing pipeline of the steam turbine; the electric regulating valve is arranged on the first heat exchange pipeline, and the safety valve is arranged on a pressure and temperature increasing pipeline between the heat exchanger and the screw heat pump.

Further, the utility model discloses still include pressure thermometer, a plurality of pressure thermometers are arranged respectively and are respectively concatenated between the part at pressure boost warming pipeline.

The utility model discloses in, the exhaust steam improves the temperature through the heat exchanger before getting into the screw rod heat pump, reduces heat pump power consumption. The screw heat pump has high pressure ratio, low unit power consumption and temperature rise higher than that of a centrifugal steam compressor, and is especially applied to working conditions of large temperature rise and high pressure at an outlet. In order to ensure the quality of steam entering a steam turbine steam supplementing pipeline, steam containing salt water and oxygen is further separated by a gas-liquid separator before entering a screw heat pump. The outlet of the heat pump supercharging system is provided with a bypass, and steam which is not in line with the pressure is recovered to the water tank at the lower end of the communicated flash tank. The heat exchanger electric regulating valve is arranged, so that the heat exchange quantity of the heat exchanger is effectively controlled, and the quality of steam entering the screw heat pump is guaranteed. The screw heat pump is adopted to effectively solve the problems of high inlet temperature and high temperature rise requirement, and the common centrifugal compressor and the Roots compressor can not meet the requirement.

Compared with the prior art, the utility model discloses have following beneficial effect and do: continuous drainage of a recovery boiler, low-grade low-parameter exhaust steam is subjected to primary heat exchange and screw heat pump pressurization, conversion of medium and high parameters is achieved, waste of heat energy and water resources caused by direct exhaust steam discharge is solved, or the problems of low efficiency of direct organic Rankine cycle power generation and difficulty in equipment cost recovery are solved, and the energy recovery utilization rate is improved to 45% from 20% of a common recovery application mode; the steam (0.47MPA, promoted to 1.3MPa) pressurized by the screw heat pump can be directly used in a steam turbine steam supplementing pipeline to participate in power generation, although part of electric energy of the screw heat pump is lost by 50-100 kW/ton of steam, the steam turbine steam supplementing section has higher enthalpy drop (1.3MPa pure condensation power generation is carried out to 0.007MPa) and higher power generation efficiency, the generated power generation amount is 180-250 kW/ton of steam, the actual net power generation amount is 130-150 kW/ton of steam, and the part of exhaust steam can be directly helped to improve the actual generated power generation amount of the whole plant by 1-1.5%. Compared with the method that the exhaust steam is subjected to organic Rankine cycle power generation or the exhaust steam is directly expanded to generate power, the exhaust steam power generation amount which enters the steam turbine to apply work after being pressurized by the screw heat pump is improved by 80% per steam ton.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention;

the system comprises a combined-row flash tank 1, a combined-row flash tank 2, a steam-water separator 3, a heat exchanger 4, a screw heat pump 5, an electric regulating valve 6, a safety valve 7, a first heat exchange pipeline 8, a second heat exchange pipeline 9, a boiler continuous drainage pipeline 10, a first recovery pipeline 11, an available steam pipeline 12, a second recovery pipeline 13, a steam turbine steam supplementing pipeline 14, a pressure boosting and temperature increasing pipeline 15, a water tank 16 and a pressure thermometer.

Detailed Description

The embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the embodiments of the present invention are based on the technical solution of the present invention and provide detailed embodiments and specific operation processes, but the scope of the present invention is not limited to the following embodiments.

Examples

Fig. 1 shows a specific embodiment, the present invention includes a parallel flash tank 1, a steam-water separator 2, a heat exchanger 3, a screw heat pump 4, an electric control valve 5, a safety valve 6, a first heat exchange pipeline 7, a second heat exchange pipeline 8, a boiler continuous drainage pipeline 9, a first recovery pipeline 10, an available steam pipeline 11, a second recovery pipeline 12, a steam turbine steam supply pipeline 13, a pressure-increasing and temperature-increasing pipeline 14, a water tank 15, and a pressure thermometer 16; the outlet of the boiler continuous drainage pipeline 9 is connected with the inlet at the upper end of the continuous drainage flash tank 1; an inlet of the pressurizing and warming pipeline 14 is connected with an outlet at the upper end of the parallel row flash tank 1, and an outlet of the pressurizing and warming pipeline 14 is respectively connected with inlets of the first recovery pipeline 10 and the steam turbine steam supplementing pipeline 11; the steam-water separator 2, the heat exchanger 3 and the screw heat pump 4 are sequentially connected in series on the pressure and temperature increasing pipeline 14 along the flow direction of the working medium; the inlet of the first heat exchange pipeline 7 is connected with the boiler connecting and discharging pipeline 9, and the outlet of the first heat exchange pipeline 7 is connected with the heat exchanger 3; an inlet of the second heat exchange pipeline 8 is connected with the heat exchanger 3, and an outlet of the second heat exchange pipeline 8 is connected with an inlet at the lower end of the parallel row flash tank 1; an inlet of the second recovery pipeline 12 is connected with an outlet at the lower end of the steam-water separator 2, and an outlet of the second recovery pipeline 12 is connected with a water tank 15 at the lower end of the parallel-row flash tank 1; the outlet of the first recovery pipeline 10 is connected with the second heat exchange pipeline 8, and the outlet of the available steam pipeline 11 is connected with the steam turbine steam supplementing pipeline 13; the electric regulating valve 5 is arranged on the first heat exchange pipeline 7, and the safety valve 6 is arranged on the pressure and temperature increasing pipeline 14 between the heat exchanger 3 and the screw heat pump 4; a plurality of pressure thermometers 16 are respectively disposed between the respective series connected components of the pressure and temperature increasing line 14.

Continuous drainage water from a boiler drum enters a continuous drainage flash tank 1 through a boiler continuous drainage water pipeline 9, and exhausted steam after expansion is about 150 ℃ and 0.47 MPa; the salt-containing oxygen-containing condensate is further separated by the vapor-liquid separator 2, and the separated condensate returns to the lower connecting water tank 15 of the continuous discharge flash tank 1 through the second recovery pipeline 12. Part of continuous drainage passes through an electric control valve 5 through a first heat exchange pipeline 7, exchanges heat with the exhaust steam from the continuous emission flash tank 1 at 150 ℃ and 0.47MPa in a heat exchanger 3, raises the temperature of the exhaust steam to 180 ℃, and returns the boiler continuous drainage to the continuous emission flash tank 1 through a second heat exchange pipeline 8 after heat exchange. The exhaust steam after temperature rise enters a screw heat pump 4 through a safety valve 6 for further steam compression, the temperature and the pressure are increased to 1.3MPa and 230 ℃, the steam meeting the requirements enters a steam turbine steam supplementing pipeline 13 through an available steam pipeline 11 to participate in pure condensation power generation, and the exhaust steam is 0.007MPa and 39 ℃. The accident working condition is directly evacuated through a safety valve 6 before the screw heat pump 4; the screw heat pump 4 enters the second heat exchange pipeline 8 after heat exchange through the first recovery pipeline 10, and then directly circulates and receives the continuous discharge flash tank 1. And remote pressure thermometers 16 are arranged at the outlet of the continuous-row flash tank 1 and the inlet and the outlet of the screw heat pump 4 and are connected with a DCS (distributed control system) of a power plant, so that the system is conveniently monitored in real time. A safety valve is added at the inlet of the screw heat pump 4, so that the direct steam exhaust under the accident working condition is ensured.

The foregoing description of the specific embodiments of the invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by those skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims

1. A boiler continuous exhaust steam screw type heat pump supercharging recovery system is characterized by comprising a continuous exhaust flash tank, a steam-water separator, a heat exchanger, a screw heat pump, an electric regulating valve, a safety valve, a first heat exchange pipeline, a second heat exchange pipeline, a boiler continuous exhaust pipeline, a first recovery pipeline, an available steam pipeline, a second recovery pipeline, a steam turbine steam supplementing pipeline, a supercharging and warming pipeline and a water tank;

the outlet of the boiler continuous drainage pipeline is connected with the upper inlet of the continuous drainage flash tank;

the inlet of the pressurizing and heating pipeline is connected with the outlet at the upper end of the parallel row flash tank, and the outlet of the pressurizing and heating pipeline is respectively connected with the inlets of the first recovery pipeline and the steam turbine steam supplementing pipeline;

the steam-water separator, the heat exchanger and the screw heat pump are sequentially connected in series on the supercharging and warming pipeline along the flow direction of the working medium;

the inlet of the first heat exchange pipeline is connected with the boiler connecting and water discharging pipeline, and the outlet of the first heat exchange pipeline is connected with the heat exchanger; the inlet of the second heat exchange pipeline is connected with the heat exchanger, and the outlet of the second heat exchange pipeline is connected with the inlet at the lower end of the parallel row flash tank;

an inlet of the second recovery pipeline is connected with an outlet at the lower end of the steam-water separator, and an outlet of the second recovery pipeline is connected with a water tank at the lower end of the parallel-row flash tank;

the outlet of the first recovery pipeline is connected with the second heat exchange pipeline, and the outlet of the available steam pipeline is connected with the steam supplementing pipeline of the steam turbine;

the electric regulating valve is arranged on the first heat exchange pipeline, and the safety valve is arranged on a pressure and temperature increasing pipeline between the heat exchanger and the screw heat pump.

2. The boiler continuous exhaust steam screw type heat pump supercharging recovery system according to claim 1, further comprising a plurality of pressure thermometers respectively disposed between the respective series-connected components of the supercharging and warming pipelines.