Described herein are two-stage catalytic heating systems and methods of operating thereof. A system comprises a first-stage catalytic reactor and a second-stage catalytic reactor, configured to operate in sequence and at different operating conditions, For example, the first-stage catalytic reactor is supplied with fuel and oxidant at fuel-rich conditions. The first-stage catalytic reactor generates syngas. The syngas is flown into the second-stage catalytic reactor together with some additional oxidant. The second-stage catalytic reactor operates at fuel-lean conditions and generates exhaust. Splitting the overall fuel oxidation process between the two catalytic reactors allows operating these reactors away from the stoichiometric fuel-oxidant ratio and avoiding excessive temperatures in these reactors. As a result, fewer pollutants are generated during the operation of two-stage catalytic heating systems. For example, the temperatures are maintained below 1.000° C. at all oxidation stages.

Provided is a correlation deriving method including the steps of: generating coal ash by incinerating coal; generating sintered ash by heating the coal ash at a predetermined heating temperature within a range of a combustion temperature of a coal burning boiler; measuring hardness of the sintered ash; measuring an exhaust gas temperature exhibited when coal which is to have the hardness is burnt in the coal burning boiler; and deriving a correlation between the hardness and the exhaust gas temperature.

A gas turbine engine includes: a combustor that combust the fuel and having an exit, a combustor exit temperature (T40) is the average temperature of flow and a combustor exit pressure (P40) is the total pressure there; a turbine including a rotor having a leading edge and a trailing edge, and wherein a turbine rotor entry temperature (T41) is an average temperature of flow at the leading edge and a turbine rotor entry pressure (P41) is the total pressure there; and a compressor having an exit, wherein a compressor exit temperature (T30) is the average temperature of flow at the exit from the compressor and a compressor exit pressure (P30) is the total pressure there (all at cruise conditions). A method of determining at least one fuel characteristic includes changing a fuel supplied to the engine; and determining a change in a relationship between T30 or P30, T40 and T41, or of P40 and P41, respectively.

The water heater may be configured to execute a normal operation in which a heating means is continuously operated in an ON state in a case where a required heat quantity is greater than or equal to a minimum heat quantity. The water heater may be configured to execute an intermittent operation in which the heating means is alternately and repeatedly operated in the ON state and an OFF state repeatedly in a case where the required heat quantity is less than the minimum heat quantity. The water heater may be configured to change a distribution ratio of a flow control mechanism in the normal operation and in the intermittent operation. An operating speed of the flow control mechanism in the intermittent operation may be faster than an operating speed of the flow control mechanism in the normal operation.

A hot water supply device includes: a first pipe connected to a water inlet; a flow detector detecting a flow of water in the first pipe; a heating mechanism heating the water; a second pipe through which warm water flows, connected to the first pipe via a third pipe; a circulating pump disposed in a path of the first pipe, sending the warm water in the third pipe toward the heating mechanism during operation; and a control device. Based on acceptance of an execution command of an instant hot water circulation mode, the control device operates the circulating pump, and, in response to a set hot water output temperature exceeding a limit temperature, adjusts a heating temperature of the heating mechanism, so that the temperature of the warm water becomes equal to or lower than the limit temperature.

The gas turbine with a plurality of combustors for igniting gas and method includes receiving first temperature measurements for a first plurality of probing points, each associated with one of the plurality of combustors. The method includes receiving second temperature measurements for a second plurality of probing points, each located downstream of the plurality of combustors. The method includes determining an association between the first plurality of probing points and the second plurality of probing points. The determining includes using the first and second temperature measurements and position information for the first and second plurality of probing points to determine swirl characteristics for the gas turbine. The swirl characteristics representing the angular shift between the ignited gas at the plurality of combustors and the ignited gas at the second plurality of probing points.

The water heater may be configured to execute a normal operation in which a heating means is continuously operated in an ON state in a case where a required heat quantity is greater than or equal to a minimum heat quantity. The water heater may be configured to execute an intermittent operation in which the heating means is alternately and repeatedly operated in the ON state and an OFF state repeatedly in a case where the required heat quantity is less than the minimum heat quantity. The water heater may be configured to change a distribution ratio of a flow control mechanism in the normal operation and in the intermittent operation. An operating speed of the flow control mechanism in the intermittent operation may be faster than an operating speed of the flow control mechanism in the normal operation.

A system and method of monitoring for sand plugging in a gas turbine engine includes sensing differential pressure across a combustor during engine operation. The sensed differential pressure is processed to determine an amount of sand plugging of combustor cooling holes, and an alert is generated when the amount of sand plugging exceeds a predetermined threshold.

A heater device including at least one control and/or regulating unit, which is provided to set an air ratio of a combustion process to a setpoint air ratio. It is provided that the control and/or regulating unit is provided to ascertain a power correction factor in at least one operating state and take it into consideration in the setting of the air ratio.

The present invention relates to a method of controlling an RPM of a blower for a gas furnace that passes air to be supplied to a room around a heat exchanger of a gas furnace. The method includes: starting operation of the gas furnace; measuring an air temperature in an outlet side of the gas furnace; measuring the RPM of the blower; determining whether the air temperature falls within a reference temperature range; and adjusting the RPM of the blower such that the air temperature falls within the reference temperature range.