Boiler, marine steam turbine propulsion system equipped with same, ship equipped with same, and boiler control method

Abstract

The present invention is provided with: a steam introduction path (74a) which extracts steam from a steam extraction section (59e) at a midway position of a superheater (37); a steam return path (74b)which returns the steam to a stream return section (59f) of the superheater (37); a desuperheater (76) for reducing the temperature of the steam; a first steam flow rate adjustment valve (80) and a second steam flow rate adjustment valve (81) which adjust the flow rate of the steam flowing to the desuperheater (76); and a first temperature sensor (72) which is disposed further towards the downstream side of the flow of steam than the steam return section (59f) of the superheater (37), and which measures a first steam temperature (T1) at a midway position of the superheater (37). The present invention is also provided with superheater-outlet-temperature relationship information (R1) which determines the relationship between the superheater-outlet temperature (T2) and the first steam temperature (T1). The first steam flow rate adjustment valve (80) and the second steam flow rate adjustment valve (81) are controlled on the basis of the superheater-outlet-temperature relationship information (R1) and the measurement result of the first temperature sensor (72), such that the superheater-outlet temperature (T2) becomes a target value.

Description

Technical field [0001] The present invention relates to, for example, a boiler such as a marine boiler, a marine steam turbine propulsion system including the boiler, a ship including the marine steam turbine propulsion system, and a boiler control method. Background technique [0002] Boilers are used to provide the main steam required by the demand side such as steam turbines. Generally, a boiler has: a burner, which burns in a furnace; an evaporator, which is heated by the combustion gas generated by the burner to generate steam; and a superheater, in which the evaporator The steam guided by the heater is overheated by the combustion gas to produce superheated steam. In addition, in response to the increase in thermal efficiency on the demand side, boilers sometimes require higher temperature and higher pressure main steam. For example, in a marine boiler that supplies main steam to a steam turbine that drives a propulsion propeller of a marine vessel, a marine reheat boiler...

AI Technical Summary

Problems solved by technology

However, even with such a structure, since the superheater is composed of the primary superheater and the secondary superheater, it becomes a long steam path. Therefore, there is a concern that the temperature of the main steam at the outlet of the superheater is obtained and fed back as described above. Control delay occurs during control, the temperature and pressure of the main steam become unstable, and the metal temperature of the heat transfer tube exceeds the allowable value due to this situation

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