Abstract: A thermal collector of solar energy that is adapted for installation in the roof structure of a building includes a cover plate to transmit sunlight, a backing, and an energy-absorbing material carried by the backing, to absorb energy of the transmitted sunlight and to transfer heat of such absorbed energy to the backing. A heat transfer medium delivers heat from the backing to a heat using apparatus such as a building heating or air conditioning system or a heat pump. The backing is designed to limit the weight of the collector and to improve its rate of thermal response upon reappearance of the sunlight. For purposes of limiting heat losses from the backing to the cover plate, the collector is evacuated and components that connect the backing with the cover plate are designed for low heat flow. Thus heat is delivered to the heat using apparatus at an elevated temperature of the heat transfer medium for improved efficiency of such apparatus.

Abstract: The electric power plant including a steam generator and a steam turbine is operated by a control system including two redundant digital computers. Switching circuitry is provided for coupling one of the computers through interface equipment to the steam generator and the turbine and a generator according to programmed computer control. A data link is established between the computers to transfer manual/automatic status and other needed data from the control computer to the standby computer. A system is provided for detecting when certain hardware and software malfunctions have occurred and for responsively transferring control to the standby computer. The standby computer is tracked to the control computer so that control computer transfer can be made reliably without disturbing the electric power generation process.

Abstract: Improved turbine speed controlling valve operation is provided through the accumulation for direct entry into a digital computer of a count of displacement pulses generated by incremental rotation of the turbine output shaft. The digital computer is operative to position the control valves in response to the speed of rotation of the output shaft calculated either as a function of the number of pulses accumulated in a predetermined interval or the time required to accumulate a preselected count, depending upon the operating point of the turbine. The accumulation of displacement pulses can be inhibited while the time measurement is being read to avoid errors in measurement.Resumption of the accumulation of displacement pulses and the measurement of time is synchronized to preserve accuracy.

Abstract: A steam turbine control system includes an operator panel and a digital computer which operates the turbine valves through an electrohydraulic control. Turbine speed and load signals and valve position signals are coupled to the computer for use by the computer control loops in developing valve control signals. Two separate displays are provided on the operator panel, one for the speed or load reference and the other for the speed or load demand. Dedicated pushbuttons on the panel enable certain other parameters such as acceleration or load rate or valve position limit to be displayed in the reference display, while other pushbuttons can be used to address and display in the reference or demand display general control system parameters. A mechanism is provided for entering changes into the computer for the various parameters and for displaying such changes in one of the displays.

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Abstract: A once-through boiler is provided with integral separators and a plurality of valves for controlling fluid flow during boiler startup. A pressure control generates an open or close signal for all of the valves and a sequence selector responds to the pressure control and a valve-in-operation logic circuit to generate valve selection signals which enable the valves to respond sequentially to the pressure control output.

Abstract: In a primary or backup control system for operating a gas turbine, a blade path temperature limit signal is generated which acts as a check on a fuel scheduling signal to the turbine which might otherwise cause excursion of the blade path temperature beyond prescribed limits. The means for generating the blade path temperature limit signal is adapted however so that a preliminary error signal is conditioned to behave in one manner in response to a condition of increasing temperature and in another manner to a condition of decreasing temperature.This two-way response is achieved by utilizing a plurality of proportional signal limiters, each one of which is matched to or tuned in accordance with the characteristics of the gas turbine. Further, the response duality is automatic and subject to the particular condition of temperature change which obtains.In addition, means are provided for generating a temperature limit signal which is clamped to a fixed, predetermined percentage of the fuel scheduling signal.

Abstract: An electric power plant having dual turbine-generators and a steam source which includes a high temperature gas-cooled nuclear reactor. Each turbine includes a high pressure portion driven by superheat steam and a lower pressure portion driven by reheat steam. A turbine bypass system permits minimum flows of superheat and reheat steam from the source at times when the turbines require flows of such steam that are less than the minimum flows. Before it is reheated, steam that has passed through the high pressure portions and their bypass lines drives auxiliary steam turbines that rotate means for propelling the coolant gas through the reactor. During acceleration of a turbine-generator to its synchronous speed, one of the steam flows through its high and lower pressure portions is varied to govern the shaft speed, while the other flow is held relatively constant, that one of the flows which is varied being determined by the shaft speed.

Abstract: An automatic control system for high pressure blower applications prevents surging under variable supply flow rate requirements and achieves maximum efficiency of operation. The supply flow rate establishes the set point of a proportional plus reset controller, the latter receiving a feedback signal corresponding to the static discharge pressure of the supply blower and responding thereto for controlling the output of the supply blower. A return blower is controlled either through a characterizer relay in proportion to the control of the supply blower to maintain a fixed precalibrated relationship between supply and return flow rates or by a further proportional plus reset controller responsive to the supply flow rate, for establishing the set point thereof, and to the return flow rate, as a feedback signal thereto, for controlling the output of the return blower.

Abstract: A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. An automatic digital portion of the control system includes a speed control which generates a speed error from the actual turbine speed and a turbine speed reference, and a proportional plus integral controller acts on the speed error to generate a fuel reference for the gas turbine fuel valve position controls after ignition and during wide range speed control. A speed reference generator includes a stored representation of speed as a function of time with zero time made equal to the point in time at which the flame goes on. The speed versus time characterization is made up of three linear parts having different slopes.

Abstract: A predetermined time delay of speed setpoint ramping of a gas turbine is imposed at ignition in its primary control system or local maintenance controller in order to compensate for the fixed energy input at ignition which might otherwise greatly increase the possibility of flameout. The imposed time delay results in the increase of an initial turbine speed tracking mode time period for the duration of the time delay.During the time delay period, fuel flow is maintained at a fixed fuel valve setting and pressure. At the termination of the time delay period, ramping of a speed setpoint at a selected rate is begun and the turbine speed is thereby increased towards synchronization speed whereat synchronization is effected.

Abstract: An electric power plant having dual turbine-generators connected to a steam source that includes a high temperature gas cooled nuclear reactor. Each turbine comprises a high pressure portion operated by superheat steam and an intermediate-low pressure portion operated by reheat steam; a bypass line is connected across each turbine portion to permit a desired minimum flow of steam from the source at times when the combined flow of steam through the turbine is less than the minimum. Coolant gas is propelled through the reactor by a circulator which is driven by an auxiliary turbine which uses steam exhausted from the high pressure portions and their bypass lines. The pressure of the reheat steam is controlled by a single proportional-plus-integral controller which governs the steam flow through the bypass lines associated with the intermediate-low pressure portions.

Abstract: An electric power plant having a cross compound steam turbine and a steam source that includes a high temperature gas-cooled nuclear reactor. The steam turbine includes high and intermediate-pressure portions which drive a first generating means, and a low-pressure portion which drives a second generating means. The steam source supplies superheat steam to the high-pressure turbine portion, and an associated bypass permits the superheat steam to flow from the source to the exhaust of the high-pressure portion. The intermediate and low-pressure portions use reheat steam; an associated bypass permits reheat steam to flow from the source to the low-pressure exhaust. An auxiliary turbine driven by steam exhausted from the high-pressure portion and its bypass drives a gas blower to propel the coolant gas through the reactor.

Abstract: An electric power plant steam turbine system with digital computer control in which control signals are generated as a function of the actual steam conditions present in each turbine section and in a manner which maintains the sum of the instantaneous power developed in each turbine section equal to the total demand placed upon the turbine system.

Abstract: A control system is disclosed for a high temperature gas cooled reactor power plant, wherein a steam source derives heat from the reactor coolant gas to generate superheated and reheated steam in respective superheater and reheater sections that are included in the steam source. Each of dual turbine-generators includes a high pressure turbine to pass superheated steam and an associated intermediate low pressure turbine to pass reheated steam. A first admission valve means is connected to govern a flow of superheated steam through a high pressure turbine, and a second admission valve means is connected to govern a flow of reheated steam through an intermediate-low pressure turbine. A bypass line and bypass valve means connected therein are connected across a second admission valve means and its intermediate-low pressure turbine.

Abstract: A combined cycle power plant includes gas and steam turbines and steam generators and a digital/analog control system. A megawatt load control system varies a fuel control signal to govern a detected power output according to a reference value. The fuel control signal determines the flow rate of fuel to the combustor of a gas turbine-generator that is adapted to use gas and liquid fuels. A flow divider comprises a plurality of gear pumps connected to rotate with a common shaft, and distributes liquid fuel equally to a plurality of nozzles of the combustor, the total liquid fuel flow to the nozzles being related to the shaft speed. The shaft speed is detected and a signal representative of the total liquid fuel flow is generated in response to the detected speed.

Abstract: A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. A surge protection system is included as part of the analog portion of the control system, and it functions in both automatic and manual modes of operation. A surge protection signal is generated to limit fuel demand as a function of speed during startup and as a function of combustor shell pressure during higher speed load operation.

Abstract: A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. A backup control is included for each of the gas turbines with an outlet or preferably blade path temperature limit control which prevents the operator from causing the turbine to operate above a temperature limit reference. The temperature limit control further restricts the rate at which the operator can move the gas turbine operating or load level toward the temperature limit value. When the turbine is operating at a load below the temperature limit value, the operator can freely move the fuel reference until the blade path temperature approaches the temperature limit value.

Abstract: A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes a superheater tube and a steam drum from which heated steam is directed through the superheater to be additionally heated into superheated steam by the exhaust gas turbine gases. An afterburner serves to further heat the exhaust gas turbine gases passed to the superheater tube and a bypass conduit is disposed about the superheater tube whereby a variable steam flow determined by a bypass valve disposed in the bypass conduit may be directed about the superheater tube to be mixed with the superheated steam therefrom, whereby the temperature of the superheated steam supplied to the steam turbine may be accurately controlled.

Abstract: A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes an economizer tube and a high pressure evaporator tube and a boiler feed pump for directing the heat exchange fluid serially through the aforementioned tubes. A condenser is associated with the steam turbine for converting the spent steam into condensate water to be supplied to a deaerator for removing undesired air and for preliminarily heating the water condensate before being pumped to the economizer tube. Condensate flow through the economizer tube is maintained substantially constant by maintaining the boiler feed pump at a predetermined, substantially constant rate.