Abstract: A method for operating a waste heat steam generator including an evaporator, an economizer having a number of economizer heating surfaces, and a bypass line connected on the flow medium side in parallel with a number of economizer heating surfaces is provided. The method makes possible higher operational safety and reliability in the control of the waste heat steam generator. For this purpose, a parameter that is characteristic of the thermal energy fed to the waste heat steam generator is used to control or regulate the flow rate of the by-pass line.

Abstract: A continuous steam generator including a combustion chamber with a plurality of burners for fossil fuel is provided. A vertical gas duct is connected downstream of the combustion chamber on the hot gas side, in an upper region via a horizontal gas duct. The outside wall of the combustion chamber is formed from evaporation pipes which are welded together in a gas-tight manner and mounted upstream of a water separator system on the flow medium side and from superheater pipes which are welded together in a gas-tight manner and mounted downstream of the water separator system. The water separator system includes a plurality of water separation elements, each element includes an inlet tube which is connected to the respective upstream evaporation for tubes, which extend into a water evacuation tube. A distributer element is arranged on the evaporator side between the respective water separator element and the inlet collector.

Abstract: A waste heat steam generator including evaporator tubes is provided. The evaporator tubes are connected in parallel on the flow medium side, a plurality of overheating tubes are mounted downstream of the evaporator tubes using a water separation system. The water separation system includes water separation elements, each water separation element being respectively mounted downstream of the plurality of evaporator tubes and/or upstream of a plurality of overheating tubes. Each water separating element includes an inlet pipe which is respectively connected upstream to the evaporator tubes, the inlet pipe extending into a water evacuation pipe when seen in the longitudinal direction. A plurality of outflow pipes branch off in the transitional area, the pipes being connected to an inlet collector of the overheating tubes which are respectively connected downstream. A distribution element is arranged on the steam side between the respective water separating element and the inlet collector.

Abstract: A method for operating a continuous flow steam generator with an evaporator heating surface is provided. A target value for a supply water mass flow is fed to a device for adjusting the supply water mass flow. In order to improve the quality of a predictive supply water or mass flow control and to maintain the enthalpy of the flow medium at the evaporator outlet particularly stable especially when load changes occur, a correction factor is taken into consideration during production of the target value for the supply water mass flow. The correction factor is a characteristic of the temporal derivative of enthalpy or the density of the flow medium at the input of one or more heating surfaces.

Abstract: A steam generator of a technical plant, in particular a power plant, comprising a heating gas passage enclosed by a gas-tight enclosing wall, wherein the heating gas passage has a number of heating surfaces through which a flow medium can flow, is to ensure especially reliable cleaning of the heating gas flowing off from the heating gas passage at an especially low design and production cost. To this end, provision is made according to the invention for at least one of the heating surfaces to be at least partly provided with a catalytic coating on its side facing the heating gas.

Abstract: A method for operating a once-through steam generator including an evaporator heating surface is provided. A target value for the supply water mass flow is fed to a device for setting the supply water mass flow, which is predefined using the ratio of the heat flow currently being transferred in the evaporator heating surface from the hot gas to the flow medium to a target enthalpy increase predefined with respect to the desired live steam condition of the flow medium in the evaporator heating surface. A forced-flow steam generator used for carrying out the method is also provided. The heat flow transferred from the hot gas to the flow medium is ascertained for this purpose allowing for a specific temperature value characteristic of the current temperature of the hot gas at the evaporator inlet and a specific mass flow value characteristic for the current mass flow of the hot gas.

Abstract: A method for operating a gas and steam turbine plant is provided. In the plant, the flue gas that escapes from a gas turbine is routed through a waste gas steam generator and where a flow medium that is used to drive a steam turbine is conducted in a flow medium circuit that includes several pressure stages. At least one of the pressure stages has an evaporator circuit with a steam collection drum that has a plurality of downpipes connected to the steam collection drum and a plurality of rising pipes downstream of the downpipes that are likewise connected to the steam collection drum and are heated by the flue gas in the waste heat steam generator. The height of the fluid column formed by the flow medium in the downpipes is monitored and a transient dry operation of the evaporator circuit can thus be detected and safeguarded against.

Abstract: The invention relates to a steam generator whose continuously heating evaporator surface is arranged in a hot gas channel for a hot gas passage in a substantially horizontal direction and which comprises a plurality of steam generating pipes passed through by flowing medium, wherein a plurality of output collectors which are mounted downstream of certain steam generating pipes, on the side of flowing medium, are oriented in the longitudinal direction thereof substantially parallel to the hot gas direction. The invention improves the steam generator such that it is possible to attain a high operational flexibility, a particularly reduced start- and load-alternation time, including starting operation or light load phases and to maintain a low-cost production. Each output collector comprises an integrated water separating element by means of which said collector is connected, on the side of flowing medium, to a plurality of downstream arranged overheating pipes of an overheating surface.

Abstract: The invention relates to a waste heat steam generator of a gas fired and steam powered generator. Said generator comprises a waste heat boiler to which exhaust gas of a gas turbine can be supplied. Said steam generator also comprises at least one evaporator which is located in the waste heat boiler and is used to produce process steam for a steam turbine. According to the invention, flue gas from a heating device can be supplied to the waste heat boiler and at least part of said flue gas can be extracted at at least one point of the waste heat boiler and redirected back to the inlet of said waste heat boiler.