Method for heating up inflow valves of turbines, and quick-closing valve for carrying out the method

Abstract

The invention relates to a method for starting up a steam turbine system (1) and heating up at least one control valve (2) of the steam turbine system (1), wherein the steam turbine system (1) comprises at least one steam generator (3), which is fluidically connected to at least one steam turbine (5) via at least one pipeline (4), wherein at least one quick-closing valve (6) and the control valve (2) are arranged inside the pipeline (4), one behind the other in the flow direction, and wherein at least one heat-up valve (7) is arranged inside the pipeline (4) upstream of the quick-closing valve (6), via which heat-up valve the live steam can be dissipated during the heat-up process. The invention also relates to a quick-closing valve for carrying out a method according to the invention of this kind.

Description

[0001]2022PF15922 1 Description Method for heating inlet valves of turbines and quick-closing valve for carrying out the method The invention relates to a method for heating inlet valves of turbines according to the features of independent patent claim 1 and to a quick-closing valve for carrying out such a method according to patent claim 2. If cold components are exposed to hot steam, film condensation occurs on the surface at saturated steam temperature. Due to the high heat transfer, high thermomechanical stresses form in thick-walled components. These stresses must be limited in the course of the service life and mechanical integrity of the components by slowly increasing the steam pressure. In order to be able to gently warm up the turbine control valves by means of controlled pressure build-up, the live steam pressure must be regulated during heating.Previous turbine protection systems and start-up step chains stipulate that the heating of the valves can only start when the main steam pressure has already reached a high level in order to provide sealing steam and evacuate the turbine. To heat up the control valves, the main steam pressure must be subsequently reduced. This sometimes always requires a separate main steam slide valve, which separates the turbine and boiler and can be used to achieve a controlled pressure build-up via whose bypass line. As an alternative to the main steam slide valve, the valves are preheated electrically in order to bypass the controlled pressure build-up. 2022PF15922 2 The previously described options for heating inlet valves require additional components and are therefore cost-intensive. Starting from the previously described prior art, the object of the present invention is therefore to provide a method for... finding, to provide for carrying out the method. The method according to the invention is solved by the features of independent patent claim 1 and the quick-closing valve according to the invention is solved by the features of independent patent claim 2. The method according to the invention for starting up a steam turbine system and warming up at least one inlet valve of the steam turbine system, wherein the steam turbine system comprises at least one steam generator which is fluidically connected to at least one steam turbine via at least one pipeline, wherein at least one quick-closing valve and one control valve are arranged one behind the other in the flow direction within the pipeline, and wherein at least one warming-up valve is arranged upstream of the quick-closing valve within the pipeline,through which the fresh steam can be discharged during the warm-up process is characterized by the following process steps: - Starting up the steam generator with the quick-closing and control valve closed; - Providing fresh steam using the steam generator; - Measuring the steam parameters of the fresh steam provided; - Opening the quick-closing valve when a specified minimum pressure is reached, whereby the control valve remains closed: 2022PF15922 3 - Continuous measurement of the temperature of the control valve; - Closing and opening of the quick-closing valve depending on the temperature of the control valve, whereby the quick-closing valve closes when a specified maximum temperature of the control valve is reached and opens when the temperature falls below a specified minimum temperature of the control valve; - Starting up the steam turbine when the specified fresh steam parameters are reached (steam, temperature,Overheating...). The inventive method enables early opening of the quick-closing valve and thus a joint warm-up of the steam generator, pipelines, and turbine valves. With the beginning of pressure buildup during start-up of the steam generator, the quick-closing valve is opened after a minimum pressure is reached, and the control valve is preheated together with the pipelines by the slow pressure build-up of the steam generator. Since steam is present at the control valve for a long time in the inventive method, the heat input into the turbine housing must be limited to avoid uneven heating and warping. This is achieved by closing the quick-closing valve during the warm-up procedure.as soon as the control valve has warmed up to a preset maximum temperature. If the temperature falls below a preset minimum temperature, the quick-closing valve is opened again. By alternately opening and closing the quick-closing valve during start-up of the steam turbine system, an approximately constant temperature is achieved in the control valve. The method according to the invention makes it possible to open the quick-closing valve very early without damaging the turbine and without having to make compromises in turbine protection. 2022PF15922 4 The method according to the invention makes it possible to eliminate the main steam slide valve, which leads to considerable cost savings. By warming up together, the overall start-up time is faster than with conventional methods. The quick-closing valve according to the invention for carrying out a method according to claim 1 is characterized in thatthat the quick-closing valve can be closed not only by spring force, but also by means of a partial-stroke solenoid valve. The quick-closing valve thus does not close suddenly against spring force, as in regular operation, but is closed slowly, ensuring gentle opening and closing of the quick-closing valve. Further advantages of the invention, which can be used individually or together, are explained below using an exemplary embodiment. It shows: Fig. 1: A steam turbine system according to the invention. The figures show only the schematic and not necessarily to scale structure. Essentially, only the components necessary for the invention are shown. Fig. 1 shows a steam turbine system 1 according to the invention.The method according to the invention for starting up the steam turbine system 1 and warming up the control valve 2 of the steam turbine system 1 is explained below. The steam turbine system 1 comprises at least one steam generator 3, which is fluidly connected to the steam turbine 5 via a pipeline 4. Within the pipeline 4, at least one quick-closing valve 6 and the control valve 2 are arranged one behind the other in the flow direction 10. In the flow direction 10, a warm-up valve 7 is arranged upstream of the quick-closing valve 6 within the pipeline 4, via which 2022PF15922 5, The and warming up the Under certain conditions, the main steam valve (8) can be eliminated entirely, resulting in significant cost savings. Due to the combined heating, the overall start-up time is faster than with conventional processes.

Claims

2022PF15922 7 patent claims te: - Starting up the steam generator (1) with the quick-closing and control valve (6, 2) closed; - Providing fresh steam by means of the steam generator (3); - Measuring the steam parameters of the fresh steam provided; - Opening the quick-closing valve (6) when a predetermined minimum pressure is reached, whereby the control valve (2) remains closed: - Continuously measuring the temperature of the control valve (2); - Closing and opening the quick-closing valve (6) depending on the temperature of the control valve (2), whereby the quick-closing valve (6) closes when a predetermined maximum temperature of the control valve (2) is reached and opens when a predetermined minimum temperature of the control valve (2) is undershot; - Starting up the steam turbine (5) when predetermined fresh steam parameters are reached. 2022PF15922 8 2. Quick-closing valve (2) for carrying out a method according to claim 1, characterized in that the quick-closing valve (2) comprises a partial stroke solenoid valve, which enables a controlled actuation of the quick-closing valve (2). öglicht.

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