Ultra-supercritical secondary reheat unit low-pressure bypass valve sealing device

The utility model provides an ultra-supercritical secondary reheat unit low-pressure bypass valve sealing device which comprises a frame and a sealing mechanism, a right side clamping hole is formed in the position, close to the lower portion, of the right side face of the frame in a penetrating mode, and a fixing hole is formed in the position, close to the upper portion, of the right side face of the frame in a penetrating mode. By arranging the sealing mechanism, when the electromagnetic valve is electrified, the air outlet of the vacuum generator is communicated with the outside, and external air enters from the air inlet pipe, is exhausted from the air outlet and then is exhausted from the air outlet end pipe, negative pressure formed by the vacuum pipe on the vacuum generator can extract and contract the air in the sealed air bag through the vacuum pipe; when the electromagnetic valve is powered off, the air outlet is not communicated with the outside, external air enters from the air inlet pipe and the