A method for adjusting and operating steam turbine interlayer steam parameters

Abstract

The invention discloses a method for adjusting and operating the interlayer steam parameters of a steam turbine. For a reheating unit, the steps include: 1) adopting a structure of directly exhausting steam in the high-pressure inner cylinder of the high-pressure cylinder; 2) using a pressure balance pipe to connect the parallel Steam source 1 and steam source 2 are connected to the interlayer between high-pressure inner and outer cylinders; 3) When the steam turbine starts up in a cold state, open the first stop valve and adjust the opening of the first throttle valve to control the steam flow in the pipeline to warm up ;4) When the steam turbine is running normally, close the first cut-off valve and the first throttle valve, open the second cut-off valve and the second throttle valve, use steam source 2 to build up the interlayer steam pressure, and have high-pressure front and rear end steam Seal leakage steam leaks into the interlayer between the high-pressure inner and outer cylinders; adjust during the process of increasing load and changing load, and properly adjust the steam source and valve to establish a suitable temperature field and pressure field for the interlayer between the high-pressure inner and outer cylinders, adapting to the high-pressure inner and outer cylinders Changes in pressure and temperature fields. This method is also applicable to the ultra-high pressure cylinder of the double reheat unit.

Description

technical field [0001] The invention relates to a high-temperature and high-pressure module of a high-parameter steam turbine unit, in particular to a method for adjusting and operating steam turbine interlayer steam parameters. Background technique [0002] With the continuous development of steam turbine technology, the inlet steam parameters of ultra-supercritical once-reheated and double-reheated steam turbine units have been increasing, the inlet steam pressure has reached 28MPa~35MPa, and the temperature is 600°C. With the development of technology, the future It may also reach 35~40MPa / 700℃. Improving the steam parameters improves the efficiency of the unit and also increases the design difficulty of the high temperature and high pressure module of the steam turbine. For this reason, the design scheme of the high temperature and high pressure cylinder block of the steam turbine is constantly optimized and innovated. [0003] At present, the traditional high temperatu...

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Problems solved by technology

However, in the start-up stage of the system, the temperature of the gas leaking into the interlayer from the shaft seal is not high, usually only 200°C, and the steam flow rate is limited, the heat exchange is insufficient, and the temperature of the outer surface of the inner cylinder and the outer cylinder body rise slowly, resulting in two major problems. question:

[0005] 1. The temperature difference between the inside and outside of the inner cylinder is large, the thermal stress of the cylinder is too large, and the safety and reliability are poor;

[0006] 2. The temperature of the inner and outer cylinders and the rotor of the steam turbine does not match, and the expansion difference of the steam turbine is not smooth. In severe cases, it will lead to wear and tear of the flow and damage the steam turbine.

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