Abstract: An energy system and a method for operating an energy system, which includes a hydrogen production unit having at least one electrolyzer for water electrolysis, the electrolyzer being thermally coupled to a cooling water circuit; and a heat pump, the heat source side of which is thermally coupled to the cooling water circuit and the heat sink side of which is coupled via a heat exchanger to a district heat or useful heat circuit. A heat store is incorporated into the district heat or useful heat circuit, the return line of which is connected downstream of the heat exchanger and the feed line of which is connected upstream of the heat exchanger of the heat pump, such that heat from the heat store is used to raise the return temperature of the district heat or useful heat circuit.

Abstract: A process for welding directionally solidified metallic materials is presented. Process parameters are targeted selected with respect to laser welding, advancement, laser power beam diameter and powder mass flow. The temperature gradient, which is fundamentally decisive for the single-crystal growth during laser cladding, may be set in a targeted manner.

Abstract: A method of welding workpieces of high-temperature superalloys is provided. Welding filler is applied in a plurality of layers to a surface of the workpiece via a heat input zone and a supply zone for supplying the welding filler into the heat input zone. The heat input zone and the supply zone on the one hand and the workpiece surface on the other hand are moved in relation to one another. A polycrystalline weld seam is generated by remelting a previously applied layer of the plurality of layers. Welding parameters are chosen such that a cooling rate during a solidifying of the material is at least 8000 Kelvins per second. Further, a welding apparatus for carrying out such a method is provided.

Abstract: A welding method for welding workpieces made of highly heat-resistant superalloys is provided. The method includes generating a heat input zone on the workpiece surface by means of a heat source, feeding welding filler material into the heat input zone by means of a feeding device, and generating a relative motion between the heat source and the feeding device on one hand and the workpiece surface on the other hand by means of a conveying device. Furthermore, according to the welding method, the mass feed rate is ?350 mg/min.

Abstract: By way of the targeted selection of method parameters in laser welding, namely feed rate, laser power beam diameter and powder mass flow, the temperature gradient can be set in a targeted manner, which temperature gradient is decisive for the single crystal growth during laser build-up welding.

Abstract: A process for welding a component in which a recess is filled by welding tracks is provided. The process includes providing a recess with a contour which delimits an outer upper surface of the component with respect to the recess. The welding tracks are laid such that the welding tracks also reach the surface outside a contour of the recess and that a plurality of welding layers are used in order to fill the recess until a last layer protrudes completely beyond the surface.

Abstract: A process for welding directionally solidified metallic materials is presented. Process parameters are targeted selected with respect to laser welding, advancement, laser power beam diameter and powder mass flow. The temperature gradient, which is fundamentally decisive for the single-crystal growth during laser cladding, may be set in a targeted manner.

Abstract: A welding apparatus for welding workpieces of high-temperature superalloys is provided. The welding apparatus includes a heat source for producing a heat input zone on the workpiece surface, a supplying device for supplying welding filler into the heat input zone and a transporting device for producing a relative movement between the heat source and the supplying device on the one hand and the workpiece surface on the other hand. The welding apparatus further includes a control unit with a control program, which carries out the relative movement in such a way that the welding power and the diameter of the heat input zone are set such that the cooling rate during the solidifying of the material is at least 8000 Kelvins per second.

Abstract: A method for directionally compacting a weld seam during build-up welding is provided. The method is used for the build-up welding of a component substrate that is compacted in a directional manner and comprises dendrites which extend in a substrate dendrite direction. The method parameters with respect to feed, laser power, weld beam diameter, powder beam focus and/or powder mass flow are designed such that they result in a local orientation of the temperature gradient to the solidification front, which is smaller than 45° with respect to the substrate dendrite direction of the dendrites in the substrate, wherein the relative speed is between 30 mm/mm and 100 mm/mm, and/or the power is between 200 W and 500 W, and/or the diameter of the laser beam on the surface of the substrate is between 3 mm and 6 mm, and/or the mass feed rate is between 30 mg/mm and 600 mg/mm.

Abstract: A process for the directional solidification of a weld seam during build up welding is provided which includes the targeted selection of process parameters for laser welding, feeding, laser power beam diameter, and powder mass flow. The temperature gradient substantially decisive for single crystal growth during laser application welding can be set deliberately.

Abstract: A welding method for welding workpieces made of highly heat-resistant superalloys is provided. The method includes generating a heat input zone on the workpiece surface by means of a heat source, feeding welding filler material into the heat input zone by means of a feeding device, and generating a relative motion between the heat source and the feeding device on one hand and the workpiece surface on the other hand by means of a conveying device. Furthermore, according to the welding method, the mass feed rate is ?350 mg/min.

Abstract: A process for welding a component in which a recess is filled by welding tracks is provided. The process includes providing a recess with a contour which delimits an outer upper surface of the component with respect to the recess. The welding tracks are laid such that the welding tracks also reach the surface outside a contour of the recess and that a plurality of welding layers are used in order to fill the recess until a last layer protrudes completely beyond the surface.

Abstract: A welding apparatus for welding workpieces of high-temperature superalloys is provided. The welding apparatus includes a heat source for producing a heat input zone on the workpiece surface, a supplying device for supplying welding filler into the heat input zone and a transporting device for producing a relative movement between the heat source and the supplying device on the one hand and the workpiece surface on the other hand. The welding apparatus further includes a control unit with a control program, which carries out the relative movement in such a way that the welding power and the diameter of the heat input zone are set such that the cooling rate during the solidifying of the material is at least 8000 Kelvins per second.

Abstract: A method of welding workpieces of high-temperature superalloys is provided. Welding filler is applied in a plurality of layers to a surface of the workpiece via a heat input zone and a supply zone for supplying the welding filler into the heat input zone. The heat input zone and the supply zone on the one hand and the workpiece surface on the other hand are moved in relation to one another. A polycrystalline weld seam is generated by remelting a previously applied layer of the plurality of layers. Welding parameters are chosen such that a cooling rate during a solidifying of the material is at least 8000 Kelvins per second. Further, a welding apparatus for carrying out such a method is provided.