A kind of CFB boiler emergency water compensating system without emergency water compensating case
Technical field
The present invention relates to CFB boiler technology field, especially relate to a kind of CFB boiler emergency water compensating system without emergency water compensating case.
Background technology
CFB (English full name CirculatingFluidized-bedBoiler, CFBB) boiler because of its have that fuel tolerance is wide, efficiency of combustion is high, Load Regulation is large, can in bed direct desulfurization and be easy to realize the many merits such as ash comprehensive utilization, be widely adopted in process steam, heat supply, cogeneration of heat and power, station boiler.For CFB boiler, have no progeny in feedwater, due to a large amount of accumulation of heats of bed material in stove and refractory material, the working medium in stove is caused constantly to be heated, a large amount of steam will be disposed to air by safety valve or enter condenser by turbine by pass, and main feed pump can not put into operation make lose water can not get supplementing.Lack the cooling of steam medium, be especially arranged in heating surface in external bed and the stronger heating surface pipe material of raying heat, the cold Bao Qiang top in such as water-cooling wall top or vapour, may damage because of overtemperature and even burn.Therefore, for ensureing the safety of water-cooling wall and other heating surface when boiler feedwater is interrupted, prevent a large amount of accumulation of heats due to bed material in stove and refractory material from causing the overheated even overtemperature of tube wall, the most effective measure for CFB boiler arranges a set of emergency water compensating system, in addition, this emergency water compensating system can also in case of emergency for Steam Turbine Bypass System provides desuperheating water and provide cooling water inflow for cone valve.
Existing CFB boiler emergency water compensating system is primarily of an independent emergency water compensating case and a set of emergency water compensating pump composition, coming from of the moisturizing water sweet-water tank of emergency water compensating case, the demineralized water changed in water sweet-water tank is pumped to emergency water compensating case by demineralized water, deliver to supply water to boiler heating surface in the high-pressure feed water pipeline before boiler economizer by emergency water compensating pump by the demineralized water in emergency water compensating case again, emergency water compensating pump centre tap is drawn as the cooling water pipeline to ash control valve.Emergency water compensating delivery side of pump is provided with self-operated type minimum flow regulating valve, when emergency water compensating pump discharge pressure is higher than setting value, emergency water compensating case will be back to, closed circuit water when simultaneously trying out weekly as emergency water compensating pump by the part moisturizing of self-operated type minimum flow regulating valve.Because emergency water compensating system is in stand-by state for a long time, the water quality in emergency water compensating case will degenerate through certain hour, therefore, regularly must carry out cleaning and water filling again to emergency water compensating case.During the periodic maintenance of emergency water compensating case or the water system of emergency water compensating case break down; such as, when desalination water pump group breaks down; if the water supply system of CFB boiler breaks down or the abnormal conditions such as interruption; and emergency water compensating system cannot carry out normal moisturizing, thus be easy to cause boiler heating surface to can not get in time, the protection of effective cooling water.
Summary of the invention
The technical problem to be solved in the present invention is: for prior art Problems existing; a kind of CFB boiler emergency water compensating system without emergency water compensating case is provided, when the water supply system of boiler is interrupted, can not only guarantees that boiler heating surface is protected timely and effectively; and operating cost is low, environment-friendly water-saving.
The technical problem to be solved in the present invention realizes by the following technical solutions: a kind of CFB boiler emergency water compensating system without emergency water compensating case, comprising water sweet-water tank and emergency water compensating pump, describedization water sweet-water tank is provided with delivery port and water return outlet, the delivery port changing water sweet-water tank is connected by pipeline with between the water inlet of emergency water compensating pump, the delivery port of emergency water compensating pump and self-operated type minimum flow regulating valve recirculation port, connected successively by pipeline between the water return outlet of change water sweet-water tank, the delivery port of described self-operated type minimum flow regulating valve is connected by pipeline with between Boiler High Pressure feedwater piping.
Preferably, describedization water sweet-water tank is at least provided with two, the delivery port of describedization water sweet-water tank is to be connected by pipeline between parallel way with the water inlet of emergency water compensating pump, and the water return outlet of describedization water sweet-water tank is to be connected by pipeline between parallel way with self-operated type minimum flow regulating valve recirculation port.
Preferably, the connecting pipe between the water return outlet of describedization water sweet-water tank and self-operated type minimum flow regulating valve recirculation port is provided with the first stop valve.
Preferably, connecting hose in the connecting pipe between described first stop valve and the water return outlet changing water sweet-water tank.
Preferably, the connecting pipe between the delivery port of describedization water sweet-water tank and the water inlet of emergency water compensating pump is provided with butterfly valve.
Preferably, connecting hose in the connecting pipe between the water inlet of described butterfly valve and emergency water compensating pump.
Preferably, the connecting pipe between the water inlet of described butterfly valve and emergency water compensating pump arranges filter screen.
Preferably, check-valves is connected with in the connecting pipe between described self-operated type minimum flow regulating valve delivery port and Boiler High Pressure feedwater piping.
Preferably, the second stop valve, pneumatic control valve and the 3rd stop valve is serially connected with in the connecting pipe between described check-valves and self-operated type minimum flow regulating valve.
Compared with prior art, the invention has the beneficial effects as follows: because emergency water compensating pump is directly from the water inlet of change water sweet-water tank, at boiler normal operation period, change water sweet-water tank and be in normal input state, make the water quality of water tank guaranteed, to avoid in water tank demineralized water because of for a long time need not and the problem causing water quality to degenerate; Simultaneously; because technical solution of the present invention can be avoided arranging independent emergency water compensating case; simplify the emergency water compensating system of boiler; be conducive to the reliability improving water charging system work; when the feed water system of boiler occurs to interrupt; can guarantee that boiler heating surface obtains the available protecting of the cooling water that emergency water compensating system provides in time; and; adopt technical solution of the present invention need not frequent clean emergency water compensating case; also demineralized water need not be refilled for emergency water compensating case; greatly save construction cost and the operating cost of CFB boiler, and environment-friendly water-saving.In addition, because power plant's water sweet-water tank at least arranges 2, when one of them water tank is isolated for some reason, another water tank be in for subsequent use in, to guarantee the reliability that emergency water compensating system is for subsequent use for a long time, the defect that when compensate for the periodic maintenance of emergency water compensating case, emergency water compensating can not drop into.
Accompanying drawing explanation
Fig. 1 is the structural map of a kind of CFB boiler emergency water compensating system without emergency water compensating case of the present invention.
Mark in figure: 1-flexible pipe, 2-first stop valve, 3-second stop valve, 4-pneumatic control valve, 5-the 3rd stop valve, 6-check-valves, 7-self-operated type minimum flow regulating valve, 8-flow nozzle, 9-filter screen, 10-butterfly valve.
Detailed description of the invention
In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with the drawings and specific embodiments, the present invention is described in detail.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
A kind of CFB boiler emergency water compensating system without emergency water compensating case as shown in Figure 1; comprising water sweet-water tank, emergency water compensating pump and self-operated type minimum flow regulating valve 7; describedization water sweet-water tank is provided with the water return outlet of locus higher than delivery port; the delivery port pipeline of describedization water sweet-water tank connects butterfly valve 10; described butterfly valve 10 is connected with the water inlet conduit of emergency water compensating pump by flexible pipe 1; flexible pipe 1 wherein can increase the flexibility that pipeline connects, and is conducive to the safety protecting butterfly valve 10 and connecting pipe.In order to ensure, improving the cleannes of the demineralized water entered in emergency water compensating pump, connecting pipe between butterfly valve 10 port of export and the water inlet of emergency water compensating pump also arranges filter screen 9, by the filtration that filter screen 9 can carry out to a certain degree to the demineralized water entered in emergency water compensating pump, improve the salt water quality entering emergency water compensating pump, be conducive to the service life extending emergency water compensating pump.
The water return outlet of describedization water sweet-water tank to be connected with the first stop valve 2 by flexible pipe 1 and to communicate, the recirculation port of the first stop valve 2 and self-operated type minimum flow regulating valve 7 is connected by pipeline and communicates, the delivery port of self-operated type minimum flow regulating valve 7 then with between Boiler High Pressure feedwater piping is connected by pipeline, and the water inlet of self-operated type minimum flow regulating valve 7 then with between the delivery port of emergency water compensating pump is connected by pipeline.Flexible pipe 1 wherein can increase the flexibility of connecting pipe, and the installation being convenient to pipeline regulates, thus plays certain shock-absorbing protecting effect to change water sweet-water tank, self-operated type minimum flow regulating valve 7 and the first stop valve 2.
In addition, as shown in Figure 1, describedization water sweet-water tank can arrange two, is divided into the first change water sweet-water tank and second to change water sweet-water tank, and described first changes water sweet-water tank, second changes water sweet-water tank with in parallel way access emergency water compensating system.Specifically, first changes water sweet-water tank, the second delivery port pipeline changing water sweet-water tank is connected successively with independent butterfly valve 10, flexible pipe 1 respectively, two flexible pipes 1 are connected with the pipeline at filter screen 9 place more simultaneously and communicate, and filter screen 9 place pipeline is connected with the inlet end of emergency water compensating pump and communicates; First changes water sweet-water tank, the second water return outlet pipeline changing water sweet-water tank is connected successively with independent flexible pipe 1, first stop valve 2 respectively, and two the first stop valve 2 entrance points are connected by pipeline with between the recirculation port of self-operated type minimum flow regulating valve 7 more simultaneously.Like this, when one of them change water sweet-water tank needs isolation for some reason, another be in for subsequent use in change water sweet-water tank then can continue as emergency water compensating pump demineralized water is provided, thus guarantee the reliability that emergency water compensating system is for subsequent use for a long time, compensate for the defect that independent change water sweet-water tank can not normally drop into because of the emergency water compensating system caused when periodic maintenance or fault.
When CFB boiler operatiopn, emergency water compensating system of the present invention by emergency water compensating pump, self-operated type minimum flow regulating valve 7 to the high-pressure feed water piped water supply of boiler.As shown in Figure 1, the second stop valve 3 is serially connected with in order successively in connecting pipe between self-operated type minimum flow regulating valve 7 delivery port and Boiler High Pressure feedwater piping, pneumatic control valve 4 and the 3rd stop valve 5, check-valves 6 is provided with in connecting pipe between self-operated type minimum flow regulating valve 7 and the second stop valve 3, also check-valves 6 is connected with in connecting pipe between the 3rd stop valve 5 and Boiler High Pressure feedwater piping, by two check-valves 6 and the second stop valve 3, 3rd stop valve 5 cooperatively interacts, the demineralized water that emergency water compensating pump is exported is timely, successfully be pumped to Boiler High Pressure feedwater piping, last to economizer import header.Another delivery port of described emergency water compensating pump is controlled valve cooling water pipeline with ash and is connected by pipeline, this another delivery port of emergency water compensating pump and the grey connecting pipe controlled between valve cooling water pipeline are serially connected with pneumatic control valve 4, flow nozzle 8, 3rd stop valve 5 and check-valves 6, simultaneously, the 3rd stop valve 5 is also serially connected with between another delivery port and pneumatic control valve 4 of emergency water compensating pump, the 3rd all stop valves 5 is in normally off, the second all stop valves 3 is in normally open, same emergency water compensating pump so just can be utilized to carry out moisturizing for ash control valve cooling water pipeline.It is to be noted, the 3rd described stop valve 5 and the second stop valve 3 also all can adopt electric check valve, control the closedown of each electric check valve by boiler control system or open, thus realizing the automated control operation of water charging system, saving manpower.
The present invention is applicable to the CFB boiler controller system that thermal power plant needs to arrange emergency water compensating system, and usual unit capacity is applicable to 300MW-1000MW grade unit, and unit number of units is applicable to 1 and multiple stage.After the invention process, compared with traditional water charging system of routine, power plant's water sweet-water tank is at least 2, when one of them water tank is isolated for some reason, another water tank be in for subsequent use in, thus the reliability that emergency water compensating system is for subsequent use for a long time can be guaranteed, the defect that when compensate for the periodic maintenance of emergency water compensating case, emergency water compensating can not drop into, when the water supply system of boiler is interrupted, cooling water can be provided in time for boiler heating surface, effectively protect the security of operation of boiler; Meanwhile, owing to eliminating independent emergency water compensating case and other pipe fittings, simplify the emergency water compensating system of CFB boiler, and water tank need not be cleaned continually and refill demineralized water, save the operating cost of CFB boiler controller system; Because emergency water compensating pump is directly from the water inlet of change water sweet-water tank, at unit normal operation period, change water sweet-water tank and be in normal input state, it can to system water supplements such as condensate water, therefore, the water quality changing the demineralized water that water sweet-water tank exports is guaranteed, the water in avoiding water sweet-water tank because of for a long time need not and the problem that causes water quality to degenerate, not only environmental protection but also economize on water.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, it should be pointed out that all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.