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 for predicting equipment performance. Input data representing an equipment parameter is obtained. The input data includes a range of values corresponding to the equipment parameter. The input data is provided to a model and a data set is generated corresponding to the model response to the input data. A set of equations is derived representing the data set. The set of equations is statistically processed to generate a probabilistic representation of equipment performance.

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.

The invention consists a dual section vessel including a first section being a turbine exhaust steam enclosure and a second section being a condensate water vessel accumulation, both sections being connected by a system of water columns. The system of water columns comprising moderate diffusers for retaining turbine exhaust steam velocity without increasing in pressure, towards impact with cold recirculated condensate water. The recirculated warm condensate water from the condensate water vessel flows through a counter current heat exchanger, and as cold condensate water to dispersion pipes connected to the ends of the diffusers. This complete system is arranged for receiving, compressing and condensing the exhaust steam from the turbine last stage. From the collision location the exhaust steam and condensate water continue to flow as "two phase flow" downward to the "condensate water vessel." In the water columns the continuous flow produces a lower pressure in the top of the column than the pressure in the bottom. The inclusion of a "counter current heat exchanger" assures a very low difference between the cooling media inlet temperature and the exiting recirculated condensate water, and a correspondingly significant reduction of the turbine exhaust steam temperature.

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.