A method for improving operational efficiency of a partial-arc steam turbine power plant during power output variations by dynamically adjusting valve point values during turbine operation. Impulse chamber pressure at each of a plurality of valve points is first determined during operation of the steam turbine at constant pressure. For each adjacent pair of valve points, an optimum constant pressure transition point pressure for transitioning from one to the other of the sliding pressure mode and constant pressure mode is then computed. The optimum constant pressure transition point pressure for each pair of valve points is converted to a corresponding percentage of the pressure difference between the adjacent pairs of valve points. The impulse chamber pressure at each valve point is then used to calculate a corresponding impulse chamber pressure for transitioning from the one mode to the other mode based upon the percentage pressure difference. During the transition, the control valve associated with the transition point and valve point is gradually closed.
A method and a device are for operating a steam turbine in which includes several no-load or light-load phases. All phases are supplied with steam in order to ensure good preheating. The supply of a phase is selected in such a way that the phase produces the least possible output, preferably no output. The enthalpy differential between the entrance to and exit from the phase is thus preferably reduced to zero.
It is proposed that, during the operation of a steam turbine of a steam power plant, the internal pressure and also the internal temperature and, in the region outside it, the external temperature be determined in at least one steam-carrying component. As a result of a change in the operating state, in particular in the event of a load change, then, the abovementioned values vary, so that, under some circumstances, the mechanical stresses which in this case act on the steam-carrying component become unacceptably high. Consequently, a spatial temperature distribution and a reference stress of the steam-carrying component are determined from the abovementioned values and compared with a material limit stress. If the reference stress is greater than the material limit stress, a limit steam pressure desired value is determined, and at least one steam valve is set in such a way that the steam pressure on the steam-carrying component corresponds approximately to this limit steam pressure desired value. By the method according to the invention, an automatic reduction in the throttling is obtained, so that the efficiency of the steam power plant, in particular in the part-load range, is increased. A device according to the invention serves for carrying out the method according to the invention.
A method to provide Primary Frequency Regulation to a steam turbine in a combined cycle plant that comprises storing energy in the form of internal energy of the steam contained within the piping and domes of the heat recovery boilers, and then using said energy when the power grid requires a sudden increase in output power. With the present method, the losses in power generation of the steam turbine, when said turbine is operating in the Primary Frequency Regulation mode, are reduced to a minimum. When the gas turbines in a combined cycle plant operate in PFR mode, the steam turbine reduces its output power because the gas turbines must operate below their rated power. The present method converts said decrease in output power of the steam turbine in a Spinning Reserve useful for PFR in said turbine. That is to say that the present method converts said Spinning Reserve in a rapid reserve, available after just a few seconds; if necessary, response times of less than 10 seconds can be attained. The present method introduces several novel steps, which constitute its essence, said steps permitting the continuous, long term operation of the steam turbine in a combined cycle plant in PFR mode, thereby ensuring at any time the effectiveness of mains frequency regulation and also guaranteeing the stability of the power generation process in said combined cycle plant.
A gas turbine combustion system and method used for generating electrical power includes a compressor that receives and compresses air. A first stage turbine nozzle is flowise connected to the compressor and receives a portion of the compressed air from the compressor within a first air flow. A torus configured combustion chamber is positioned around the first stage turbine nozzle and receives a portion of the compressed air from the compressor within a second air flow that is passed through the combustion chamber where air and fuel are mixed and combusted. The air is discharged at the first stage turbine nozzle to mix with the first air while achieving a dry low NOx combustion.
A steam turbine has multiple valves for introducing steam into a steam turbine. Each of the input valves introduce steam flow around the entire the 360 degree arc. The set of nozzles are each divided into a plurality of chambers. Each set of chambers extends around the full arc of the turbine. Each set has a valve. The chambers are designed so that all valves are open when the turbine is running at maximum output. The chambers are sized such that valve throttling losses are minimized when the turbine is at its normal operating condition.
