摘要:
A method for determining a condition of an electric igniter of a gas turbine burner and a measurement device for a gas turbine burner are provided. By means of the method and the measurement device it is possible to prevent false starts of gas turbines as a result of a nonfunctional igniter. The method provides for a time-dependent signal characterizing the ignition current of an igniter to be compared to an upper threshold value and a lower threshold value and at the same time to compare the characterizing signal to a mean target current value, by which the ignition current should fluctuate randomly when the igniter is functioning properly.
摘要:
The invention relates to a safety device for an industrial boiler (CHA) comprising electromechanical relays (REn, RS), which are connected in series in order to form an electromechanical safety chain (CHA), and at least one shunt relay (RTn) which is normally open and mounted in parallel to one of the electromechanical relays (REn). Said shunt relay is controlled by an automation (API) so that it is closed during a time delay. According to the invention, the shunt relay (RTn) is provided with a contact that is connected to an electronic circuit (CEn) and said electronic circuit (CEn) opens an electromechanical relay (RS) which is mounted in series in the safety chain when the shunt relay (RTn) is closed longer than the time delay. Given said arrangement. In the event of an automation failure, the time delay is ensured by the electronic circuit so that a satisfactory level of safety is guaranteed in relation to the installation.
摘要:
An integrated electronic control arrangement is disclosed in the illustrative environment of burner such as in a gas-fired furnace. The control incorporates a self-test feature which shuts down the furnace in the event of any one of a number of possible sensed faults. Self-testing occurs automatically before an attempt at ignition and during furnace operation. Proper functioning of the sensor which senses for induced air flow through the burner combustion chamber is tested prior to enabling a fan which causes that induced air flow. Air flow is confirmed by sending to and receiving back from the sensor a sequence of pulses. Should air flow not be sensed during a combustion period, combustion is terminated. A flame sensor is provided for determining the presence of a flame in the combustion chamber. During times when a flame should be present, pulse sequences are sent to and received back from the flame sensor to confirm that a flame is present. When it is known that no flame is present, if sent pulses are received back, a fault has occurred and the system locks out. If, at any time, any pulses are received when none were sent the system also locks out.
摘要:
A flame detector, for use with a photocell which produces a flame signal when the photocell is exposed to a flame, is used for detecting the presence of a flame. An input circuit is coupled to the photocell for receiving and buffering the flame signal. The buffered flame signal is filtered and amplified in a filter. An output circuit further amplifies the filtered flame signal providing an output flame signal. A switch is also used in the flame detector for substantially short circuiting the flame signal to a known value upon receiving a switch-close signal from either a test computer or from a hot refractory detection circuit. A flame-out condition is detected by the hot refractory detection circuit which generates an HRD signal causing the flame signal to be substantially short circuited to a known value thereby eliminating a false flame signal caused by hot refractory shimmering.
摘要:
An integrated electronic control arrangement is disclosed in the illustrative environment of burner such as in a gas-fired furnace. The control incorporates a self-test feature which shuts down the furnace in the event of any one of a number of possible sensed faults. Self-testing occurs automatically before an attempt at ignition and during furnace operation. Proper functioning of the sensor which senses for induced air flow through the burner combustion chamber is tested prior to enabling a fan which causes that induced air flow. Air flow is confirmed by sending to and receiving back from the sensor a sequence of pulses. Should air flow not be sensed during a combustion period, combustion is terminated. A flame sensor is provided for determining the presence of a flame in the combustion chamber. During times when a flame should be present, pulse sequences are sent to and received back from the flame sensor to confirm that a flame is present. When it is known that no flame is present, if sent pulses are received back, a fault has occurred and the system locks out. If, at any time, any pulses are received when none were sent the system also locks out.
摘要:
A control device for monitoring the presence or absence of a flame through the use of an ionization tube sensitive to radiation of a predetermined wavelength and which is emitted by the flame. Energy storage means are employed to accumulate the signals generated by the ionization tube. The stored energy is periodically pulsed to discharge the stored energy in an intermittent manner thereby delaying the generation of a signal representing the absence of a flame. The state of the energy storage means is digitized at the aforesaid periodic rate and is restored generally to its undigitized form before controlling the delayed generation of a flame-out signal.