High-parameter stale refuse co-combustion power generation system with reheating function
Technical Field
The utility model belongs to the technical field of msw incineration, concretely relates to old rubbish of high parameter with reheat mixes burning power generation system.
Background
Along with the urban development in China and the continuous improvement of the living standard of people, the urban garbage yield is increased day by day. The garbage accumulated in China over 60 hundred million tons over the years occupies more than 300 million acres of land for garbage stacking and landfill, two thirds of more than 600 cities in China are surrounded by garbage, and the 'garbage enclosing city' becomes the current situation and causes serious environmental pollution, ecological damage and life interference to surrounding cities. After the primary garbage is buried and degraded by microorganisms for years, the primary garbage can be thoroughly decomposed and stably mineralized, and becomes stale garbage, so that the method has the advantages of stable property, high heat value and the like. At the moment, the old garbage in the landfill can be excavated, classified and recycled, so that the resources in the old garbage can be obtained, and the site can be vacated for later use. However, heavy metals and dioxin generated by the combustion of stale refuse are harmful to human bodies, wherein the heavy metals are incinerated and are enriched in incineration product slag and fly ash, and if the heavy metals are randomly discharged, the heavy metals are accumulated in the environment, and finally serious secondary pollution is caused. If the stale refuse is reduced by using the stale refuse and the raw refuse mixed combustion power generation mode, the problem of refuse occupation can be effectively solved, and the problems of high-temperature corrosion to incineration equipment, shortened service life, reduced reliability and the like caused by overhigh heat value when stale refuse is combusted independently can also be reduced.
Use the project of waste incineration steadily to increase as the background, in order to satisfy the environmental protection requirement, when reducing the operation input cost of power plant, reach the purpose that promotes waste incineration thermal efficiency, boiler thermal efficiency and the whole generating efficiency of power plant, use high parameter waste incinerator to carry out the old rubbish and the primary rubbish of high calorific value and mix and burn, can provide effective solution for above-mentioned demand.
SUMMERY OF THE UTILITY MODEL
The utility model discloses a main aim at overcomes prior art's shortcoming and not enough, provides one kind.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
a high-parameter stale refuse co-combustion power generation system with reheating function comprises a grate furnace, a steam drum, a steam turbine, a power generator, a condenser, a condensate pump, a deaerator and a water pump which are arranged in a boiler circulation sequence and connected through pipelines;
the steam drum is internally provided with a middle reheater and a heat exchanger, and the heat exchanger is arranged in front of the middle reheater; the steam turbine comprises a steam turbine high pressure cylinder and a steam turbine low pressure cylinder;
the steel plates of the front arch and the rear arch of the grate furnace are provided with water-cooled walls, namely the water-cooled walls of the front arch and the rear arch, and the water-cooled walls are used for absorbing partial heat generated in an incineration hearth when stale garbage is co-combusted on the incineration grate;
the front and rear arch water-cooled walls are connected with a heat exchanger in the steam drum through pipelines to form independent water circulation;
steam generated by boiler heating water enters a steam turbine high-pressure cylinder along a pipeline, the steam is driven to do work and a generator is enabled to generate power, the steam coming out of the steam turbine high-pressure cylinder enters a steam turbine low-pressure cylinder, low-pressure low-temperature steam extracted from the steam turbine low-pressure cylinder enters a middle reheater in a steam drum to be reheated, then the steam returns to the steam turbine low-pressure cylinder to do work with original gas in the steam drum to enable the generator to generate power, finally, the steam exhausted from the steam turbine low-pressure cylinder is condensed into water through a condenser, then, the water is deoxidized through a deaerator, and finally, the steam is conveyed back to the boiler through a water pump.
Furthermore, the steam-water separator is arranged outside, and low-temperature and low-pressure steam extracted from the low-pressure cylinder of the steam turbine firstly passes through the steam-water separator for steam-water separation and then enters the intermediate reheater for reheating.
Compared with the prior art, the utility model, following advantage and beneficial effect have:
1. the utility model adds water cooling walls on the steel plates at the front and rear arches of the hearth of the grate furnace, absorbs the heat generated during the blending burning of stale garbage, transfers the heat to the low-temperature and low-pressure steam extracted from the low-pressure cylinder, and increases the thermal capacity of the boiler;
2. the utility model discloses the circulation between the heat exchanger that sets up in the steam pocket and that link to each other with the front and back arch water-cooling wall and the middle reheater is driven through the density difference, improves the reheat temperature of steam in the steam turbine low pressure jar, improves the acting efficiency of steam turbine; the exhaust humidity of the low-pressure turbine is reduced, and the safety is ensured.
3. The utility model does not directly discharge the steam-water mixture generated after the water wall is heated into the steam pocket, thereby ensuring the steam quality of the boiler and facilitating the independent maintenance of the circulation formed by the water wall and the heat exchanger connected with the water wall;
4. the utility model discloses carry out the reheat of steam in the steam pocket, can avoid carrying out reheat in the boiler, middle re-heater receives high temperature corrosion's influence.
Drawings
FIG. 1 is a schematic diagram of a high-parameter drum intermediate reheating system for stale refuse co-combustion;
FIG. 2 is a schematic front and rear arch view of a grate incinerator;
the reference numbers illustrate: 1-a boiler; 2-a pipeline; 3 a-a high pressure cylinder of the steam turbine; 3 b-a low pressure cylinder of the steam turbine; 4-a generator; 5-a gas condenser; 6-a condensate pump; 7-a deaerator; 8-steam drum; 9-intermediate reheater; 10-a heat exchanger; 11-a steam-water separator; 12-a water pump; 13-a grate furnace; 14-front and rear arch water-cooled walls; 14 a-front arch water-cooled wall; 14 b-rear arch water-cooled wall; 14 c-an incinerator hearth; 14 d-incineration grate.
Detailed Description
The present invention will be described in further detail with reference to the following examples and drawings, but the present invention is not limited thereto.
Examples
As shown in fig. 1, the utility model discloses a high-parameter stale refuse mixed combustion power generation system with reheating, which comprises a grate furnace 13, a steam drum 8, a steam turbine, a generator 4, a condenser 5, a condensate pump 6, a deaerator 7 and a water pump 12 which are arranged according to the circulation sequence of a boiler 1 and are connected through a pipeline 2;
the steam drum is internally provided with a middle reheater 9 and a heat exchanger 10, and the heat exchanger is arranged in front of the middle reheater; the steam turbine includes a turbine high pressure cylinder 3a and a turbine low pressure cylinder 3 b.
As shown in fig. 2, water-cooled walls, namely a front arch water-cooled wall 14a and a rear arch water-cooled wall 14b, are added on the steel plates of the front arch and the rear arch of the grate furnace, the aged refuse and the primary refuse are co-burned on an incineration grate 14d, and the water-cooled walls absorb part of heat generated in an incineration hearth 14 c; the front and rear arch water-cooled walls 14 are connected with a heat exchanger in the steam drum through pipelines to form independent water circulation; and a heat exchanger connected with the front arch water-cooled wall and the rear arch water-cooled wall 14 through pipelines is arranged in front of an intermediate reheater in the steam drum.
In this embodiment, the system further includes an external steam-water separator 11, and the steam extracted from the low-pressure cylinder of the steam turbine is subjected to steam-water separation by the steam-water separator and then enters the intermediate reheater.
The power generation method based on the power generation system of the embodiment comprises the following steps:
s1, heating steam generated by water supply by a boiler, and enabling the steam to enter a steam turbine along a pipeline;
s2, the generated steam firstly enters a high-pressure cylinder of the steam turbine to drive the high-pressure cylinder of the steam turbine to do work and enable the generator to generate electricity, and the steam coming out of the high-pressure cylinder of the steam turbine enters a low-pressure cylinder of the steam turbine;
s3, carrying out water-vapor separation on low-pressure low-temperature steam extracted from the low-pressure cylinder of the steam turbine through a steam-water separator, then entering a middle reheater in a steam drum to be reheated, then returning to the low-pressure cylinder of the steam turbine, mixing the reheated gas with original gas in the cylinder to expand and apply work and enable a generator to generate electricity, finally condensing the steam discharged from the low-pressure cylinder of the steam turbine into water through a condenser, then deoxidizing through a deaerator, and finally conveying the water back to the boiler through a water pump.
The utility model can reduce the exhaust humidity of the low pressure turbine in the intermediate reheating process of the steam; the reheater is arranged in the steam drum, so that the reheater is prevented from being corroded by high temperature in the heat exchange process, and the service life of the reheater is prolonged; meanwhile, the steam pocket has a certain buffering function, so that the temperature adjusting range of the intermediate reheater is reduced, meanwhile, a heat exchanger connected with front and rear arch water-cooled walls is arranged in front of the intermediate reheater, and the heat exchange temperature of the intermediate reheater is improved by improving the steam temperature of the steam pocket.
It should also be noted that in this specification, terms such as "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.