Abstract:
A device for emergency operation of pneumatic or hydraulic actuators. For normal operation of the actuator, an operation cycle includes at least a proportional valve for switching to different operational conditions of the actuator and related engine components. The proportional valve is arranged in a supply line of pressurized liquid/gas and in a drain line connected to a tank, and control means for operation control and supervising functions. An emergency cycle is attached to the operation cycle of the actuator which is provided with: at least one solenoid valve for initiating an emergency operation impulse in case of detected failures; a plurality of pneumatically/hydraulically operated switch valves which may be activated through said impulse of an emergency signal from said solenoid valve; and whereby the emergency cycle is adapted to bypass said proportional valve in emergency situations and to either block said actuator in its actual position or to bring said actuator in a predefined safe position.
Abstract:
An air quality control system (AQCS) 14 useful for treating flue gas FG, such as flue gas FG produced by a fossil fuel fired boiler 12 is described. The AQCS 14 is equipped with a dry scrubber low load distributor device 66. With the low load distributor device 66, flue gas FG flow through a dry scrubber reactor 36 is stabilized under varying plant 10 load conditions to maintain AQCS 14 stability, efficiency and effectiveness.
Abstract:
A heat exchanger apparatus for receiving water from a steam drum (1) and providing steam and heated unevaporated liquid water to the steam drum includes a first evaporator (EVAP-1) and a second evaporator (EVAP-2). The first evaporator can receive water from a steam drum via a first feed conduit (9) and the second evaporator can receive water from a second feed conduit (11). Both evaporators can output heated fluid to the steam drum via a combined evaporator output conduit (13). Each first evaporator passageway (14) only makes a single pass through a gas duct (15) having a heated gas flow (7) passing therethrough while each second evaporator passageways (24) can make one or more passes through the gas duct for transferring heat from the gas to the fluid within the evaporators. A portion of the first feed conduit can also have a pre-specified volume a pre-specified height below the first inlet (10).
Abstract:
The molten salt solar tower system 100 is provided for controlling molten salt temperature in a solar receiver 130 for effective operation of the system 100 while without degrading physical properties of molten salt. The system 100 includes two circuits, first 140 and second 150. The first circuit 140 is configured to supply relatively cold molten salt in the solar receiver 130 for heating, and the second circuit 150 is configured to supply a predetermined amount of the relatively cold molten salt in the first circuit 140, as and when the temperature of the relatively hot molten salt circulating through the solar receiver 130 exceeds a predetermined set temperature value thereof.
Abstract:
The invention pertains to a power plant including a gas turbine, a heat recovery boiler arrangement with at least a boiler inlet, and an outlet side with a first exit connected to a stack and a second exit connected to a flue gas recirculation, which connects the second exit to the compressor inlet of the gas turbine. The heat recovery boiler arrangement includes a first boiler flue gas path from the boiler inlet to the first boiler exit, and a separate second boiler flue gas path from the boiler inlet to the second boiler exit. Additionally, a supplementary firing and a subsequent catalytic NOx converter are arranged in the first boiler flue gas path. Besides the power plant a method to operate such a power plant is an object of the invention.
Abstract:
The feedwater preheating system includes a feedwater tank and a constant volume recirculation pump. The feedwater tank is adapted to store the feedwater. The feedwater tank includes feed and return lines. The feed line is adapted to feed the feedwater to the HRSG, and the return line enables returning of the feedwater into the feedwater tank. The return line precludes a control valve, and is configured to the feedwater tank to reduce component loss while feedwater recirculation. The constant volume recirculation pump is configured in the feed line to recirculate the feedwater between the HRSG and the feedwater tank. The pump is capable of recirculating the feedwater at constant speed and volume to reduce heat loss while feedwater recirculation, as against the prior art feedwater preheating systems.
Abstract:
The invention relates to a cooled wall segment in the hot gas path of a gas turbine, particularly to a cooled stator heat shield. Such components have to be properly cooled in order to avoid thermal damages of these components and to ensure a sufficient lifetime. The wall segment according to the invention includes a first surface, exposed to a medium of relatively high temperature, a second surface, exposed to a medium of relatively low temperature, and side surfaces connecting said first and said second surface and defining a height of the wall segment. At least one cooling channel for a flow-through of a fluid cooling medium extends through the wall segment. Each cooling channel is provided with an inlet for the cooling medium and an outlet for the cooling medium. The at least one cooling channel includes at least two heat transfer sections, a first (in the direction of flow of the cooling medium) heat transfer section extending essentially parallel to the surface of relatively high temperature in a first distance and a second heat transfer section extending essentially parallel to the surface of relatively high temperature in a second distance, whereby the second distance is lower than the first distance.
Abstract:
The present disclosure refers to a method for operating a gas turbine with sequential combustors having a first-burner, a first combustion chamber, and a second combustor arranged sequentially in a fluid flow connection. To minimize emissions and combustion stability problems during transient changes when the fuel flow to a second combustor is initiated the method includes the steps of increasing the second fuel flow to a minimum flow, and reducing the first fuel flow to the first-burner of the same sequential combustor and/or the fuel flow to at least one other sequential combustor of the sequential combustor arrangement in order keep the total fuel mass flow to the gas turbine substantially constant. Besides the method a gas turbine with a fuel distribution system configured to carry out such a method is disclosed.
Abstract:
An electricity production system configured to operate in accordance with a method of operating an electricity production system that at least includes the steps of: determining an oxygen distribution between oxygen gas to be separated by an air separation unit (“ASU”) and oxygen gas stored in a storage tank of the ASU to be fed to the boiler unit, determining a carbon capture value for a gas processing unit, determining a power consumption value for the gas processing unit and the ASU, determining a total power demand value based on the power consumption value of the gas processing unit and the ASU, and on a determined electricity demand, and controlling the boiler unit, the turbine, the ASU, and the gas processing unit based on the determined total power demand along with correcting signals generated from a coordinated Model Predictive Control.