DE3216588C1 - Device for dewatering the superheater heating surfaces of a steam generator - Google Patents

Description

The invention relates to a device for draining the superheater heating surfaces of a steam generator with at least one single-stage or multi-stage, single-flow or multi-flow and drainable superheater, the Drainage line or drainage lines of a superheater stage, preferably the lowest superheater stage, are equipped with a water level measuring device and all drainage lines with a drainage collector are connected, which is geodetically deeper than the water level measuring device lies.

It is already known that the condensate occurring in the superheaters of a steam generator by means of Water level measuring devices are monitored and discharged when limit values are reached (large power plant Mannheim, boiler 18).

By using such devices, proper drainage of a superheater, especially when starting up a steam generator after a long standstill or during the Standstill can be achieved when large amounts of condensate are present.

In the case of steam generators with several multi-stage and multi-flow superheaters, however, it is constructive and Very expensive in terms of cost, the individual superheater stages each with a water level measuring device equip.

It is therefore an object of the invention to provide a device for draining the superheater heating surfaces Steam generator with at least one single or multi-stage, one or multi-flow drainable To create superheaters, in which the condensate level by means of a single water level measuring device is monitored.

This object is achieved in that check valves are arranged in those drainage lines which are not equipped with a water level measuring device, with all drainage pipes together with the drainage collector form a communicating pipe system and the Drainage collector through a shut-off valve controlled by the water level measuring device a drain line can be emptied.

This solution has the advantage that - due to the principle of communicating pipes - the drainage all stages of a superheater can be monitored with only one working fluid level measuring device can.

The invention is explained in more detail with reference to the description and the drawing:

The drawing shows the scheme of a double-flow, multi-stage superheater. The superheater levels 1,2 and 3 are provided with inlet collectors 4, 5 and 6 and outlet collectors 7, 8 and 9. Saturated steam from an evaporator, not shown, of a steam generator flows through the lines 26 to the superheater inlet header 4. The superheater stages 1 and 2 and the superheater stages 2 and 3 are through the lines 11 or 10 connected to each other. Superheater steam leaves superheater stage 3 through lines 27 and flows to a turbine, not shown. The inlet headers 4, 5 and 6 have drainage lines 14, 15 or 13, 16 or 12, 17, which each open into the drainage collector 23. Of the The drainage collector 23 is provided with the drainage line 24 equipped with a shut-off valve 25. the Drainage lines 12, 13, 15, 16 and 17 are each provided with a check valve 22, the drainage line 14, however, is provided with a water level measuring device 18. From the drainage pipes 12, 13, 15, 16 and 17 each branch with shut-off valves 19 upstream of the check valve 22 equipped lines 21 or 21a, 21c, 21 f /, 21e from, which lead to the drain collector 20.

From the drainage line 14, after the water level measuring device 18, the line 2tb branches off, which also leads to the drain collector 20. A line 28 leads from the drain collector 20 to an expansion (not shown). The valves 19 serve to drain condensate into the expansion valve when the steam generator is switched off or to drain water after pressure tests have taken place.

When the valves 19 and 25 are closed, the condensate accumulating in the superheater stages 1, 2 and 3 arrives from the inlet headers 4, 5 and 6 through the drainage lines 12, 13, 14, 15, 16 and 17 to Drainage collector 23. When the drainage collector 23 is filled with condensate, it rises Condensate in the drainage line 14. Those arranged in lines 12, 13, 15, 16 and 17 Check valves 22 prevent the condensate from flowing back into these lines. If the condensate in the drainage line 14 exceeds a predetermined maximum level, causes the working fluid water level measuring device 18 the opening of the shut-off valve 25. When the condensate in the drainage line 14 has dropped to the predetermined level, the shut-off valve 25 closes again. This The process is repeated until new condensate no longer exceeds the maximum level.

1 sheet of drawings

Claims (1)

Claim: Device for draining the superheater heating surfaces of a steam generator with at least a single or multi-stage, single or multi-flow and drainable top heater, whereby the drainage line or lines of a superheater stage, preferably the lowest superheater stage, with a water level measuring device (18) are equipped and all drainage lines (12 to 17) with a drainage collector (23) are connected, which is geodetically deeper than the water level measuring device (18) is, characterized in that check valves (22) in those Drainage lines (12,13,15,16,17) arranged are not equipped with the water level measuring device (18), with all drainage lines (12 to 17) together with the drainage collector (23) form a communicating pipe system and wherein the drainage collector (23) is connected by a water level measuring device (18) controlled shut-off valve (25) can be emptied via a drain line (24). 25th