Abstract: A steam generator has a pressure casing formed in the shape of a drum. The longitudinal axis of this pressure casing is oriented horizontally or largely horizontally. A hollow tube (1) is formed in such a way that at least two hollow tube sections (1?) are provided, preferably a plurality of hollow tube sections which extend predominantly parallel to each other, and which are arranged in stack-form vertically or vertically offset above each other, and which in each case are interconnected in pairs at an end section, wherein this hollow tube is located in the vertical direction above the feed section (8).

Abstract: In a combined gas/steam power plant with a once-through forced-flow steam generator, a separation bottle (25) is connected between the evaporator (22) and the superheater (23). To clean the water/steam circuit, in the full-load or the part-load mode, a larger quantity of water than necessary is conveyed through the economizer (21) and the evaporator (22) via a feed pump (20). The quantity of water is selected such that wet steam passes into the separation bottle (25). This water fraction, together with all the impurities contained therein, is separated in the separation bottle and is drawn off via a clarifying line (29). Overfeeding can be regulated in such a way that the fresh steam temperature corresponds to the nominal value of the respective load point. When cleaning of the water/steam circuit is intended in the full-load mode, and without overfeeding the system, steam from a stage of incomplete evaporation can be extracted out of the evaporator and led into the separation bottle.

Abstract: The cooling air cooler (10) for power plants of combined operation is designed as a helix steam generator which works on the countercurrent principle and is located in a vertically arranged cylindrical pressure vessel (23) and the spirally coiled tubes (30) of which fill the space between an inner (26) and an outer (41) jacket tube, water (12) being capable of being supplied to the tubes (30) via a conduit (32) and steam (14) being capable of being discharged from the tubes (30) via a conduit (33), the evaporating water (12) flowing through the helix from the bottom upward and the cooling air (11), capable of being supplied by the compressor (1) via an inflow conduit (24), flowing through the helix from the top downward, and the air (11) experiencing deflection before reaching an outflow conduit (25) at the lowest point in the pressure vessel (23) after flowing out of the helix.

Abstract: In a method for feed water control in waste heat steam generators, in particular drum boilers with a circulating pump (9) and drum boilers with natural circulation employed in combination power plants, wherein, by a three-component control by means of a superordinated level regulator (13) and a flow-through regulator (14) subordinated to the level regulator (13), the set value (S.sub.in) of the flow-through regulator (14) is displaced by the level regulator (13) in such a way that the level in the drum (6) is always regulated to the set value (S), regardless of interfering effects, the flow-through regulator (14) for the feed water flow (m.sub.s) is guided by the heat amount (Q.sub.AG) in the exhaust gas flow. The output signal of the flow-through regulator (14) for the feed water flow (m.sub.s) is limited, wherein as the function of the heat amount (Q.sub.AG) in the exhaust gas flow a selection is made between a limit value (m.sub.1) for the start-up operation and a limit value (m.sub.

Abstract: A mixed-pressure waste-heat boiler (7) has a forced-flow steam generator, essentially composed of a low-pressure economizer (15), of a low-pressure drum (17) and of a low-pressure evaporator (16), and a once-through forced-flow steam generator, essentially composed of a high-pressure economizer (21), of a high-pressure evaporator (22) and of a high-pressure superheater (23). The high-pressure economizer (21) is fed from the steam drum (17) of the forced-circulation steam generator via a high-pressure feed pump (20). Arranged between the high-pressure evaporator (22) and high-pressure superheater (23) is a separation bottle (25) which is connected to the steam drum (17) via a recirculation line (26). During startup, until superheated conditions are reached at the outlet of the high-pressure evaporator (22), high-pressure saturated water is recirculated into the drum (17) of the forced-circulation steam generator via the separation bottle (25).