JPH06108879A - Gas turbine utilizing catalyst combustor - Google Patents

Abstract

PURPOSE:To provide a gas turbine, for which a catalyst combustor for shortening the time required for warming a catalyst therein, is used. CONSTITUTION:At the time of starting a gas turbine, a circulation shut-off valve RV provided on a circulation channel RP is 'opened', and an exhaust shut-off valve EV provided on an exhaust channel EP is 'closed'. The combustion gas generated in a combustor CC is circulated into the intake port of a compressor CP through the circulation channel, and is fed to the catalyst combustor again in a compressed form, and the catalyst in the catalyst combustor can thus be warmed up promptly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine using a catalytic combustor, and more particularly to a gas turbine using a catalytic combustor capable of shortening the time required for catalyst warm-up and improving fuel consumption.

[0002]

2. Description of the Related Art In order to reduce the generation of nitrogen oxides due to the combustion of fuel in a gas turbine combustor, there has been proposed a catalytic combustor in which fuel is burned by a catalytic reaction instead of flame combustion. Since it is necessary for the catalyst in the combustor to reach a predetermined temperature or higher in order to continue catalytic combustion, it is common to perform flame combustion to warm up the catalyst when the gas turbine is started.

Since nitrogen oxides are generated in flame combustion, it is necessary to quickly warm up the catalyst. As a method of shortening the heating time of the catalyst, a heat exchanger for warming compressed air with exhaust gas is used. It is proposed to install it (see Japanese Utility Model Laid-Open No. 61-144370).

[0004]

However, in the above-mentioned invention, the compressor directly sucks in the atmosphere even though the flow rate of the exhaust gas is small at the start of the gas turbine, so that the temperature of the air supplied to the combustor is reduced. The ascending speed is small and it is unavoidable that the time for flame burning is prolonged.

The present invention has been made in view of the above problems, and an object thereof is to provide a gas turbine using a catalytic combustor capable of shortening the time required for warming up the catalyst in the combustor. To do.

[0006]

According to the present invention, there is provided a gas turbine using a catalytic combustor as a combustor and a catalytic combustor having a heat exchanger for heating compressed air with exhaust gas of an output turbine. Another feature is that a recirculation flow passage is provided to recirculate the catalyst in the catalytic combustor from the flow passage downstream of the combustor to the intake port of the compressor when the temperature of the catalyst is below the activation temperature.

[0007]

In the gas turbine using the catalytic combustor according to the present invention, when the temperature of the catalyst is below a predetermined temperature, the combustion gas or exhaust gas in the downstream of the combustor is recirculated to the intake port of the compressor and compressed. It accelerates the temperature rise rate of air and accelerates the warm-up of the catalyst.

[0008]

1 is a block diagram of a first embodiment of a gas turbine using a catalytic combustor, in which a compressor CP and an output turbine GT are directly connected by a shaft S. Axis S
Is further extended to the compressor CP side and is connected to a load L which is, for example, driving wheels of an automobile.

The intake air compressed by the compressor CP passes through the intake side flow path of the heat exchanger HX and the catalytic combustor CC.
Is supplied to. In the catalytic combustor CC, the fuel FF mixes with the compressed air and reacts and burns to form combustion gas. The output turbine G
After expanding and working at T, it is discharged to the atmosphere via the so-called Noguchi catalyst CT for removing nitrogen oxides and the exhaust gas flow path EP of the heat exchanger HX. An exhaust cutoff valve EV that cuts off the flow of the exhaust gas is installed in the exhaust gas passage EP.

The catalytic combustor CC is provided with a fuel injection valve INJ for injecting fuel, a spark plug PL for performing flame combustion at the time of starting, and a catalyst CCT for performing catalytic combustion. The recirculation flow path RP is provided so as to connect the wake of the catalytic combustor CC and the suction port of the compressor CP, and the recirculation flow path RP is provided with a recirculation cutoff valve RV for cutting off the flow of the recirculation flow path. There is.

Downstream of the catalytic combustor CC, a temperature measuring means TC, which is, for example, a thermocouple, is installed, and a control unit CNT.
Entered in. Further, from the control unit CNT, the fuel injection valve IN
Control signals for J, the spark plug PL, the exhaust cutoff valve EV, and the recirculation cutoff valve RV are output. The flow path indicated by a thick line in FIG. 1 is a flow path in which compressed air and combustion gas are flowing when the gas turbine is started, that is, when the catalyst CCT is still below a predetermined temperature and flame combustion is performed. It represents.

In this state, the gas turbine is driven by a starter device such as a cell motor, and the exhaust cutoff valve E
V is "closed" and the return valve RV is "open". Therefore, since the combustion gas is recirculated to the intake port of the compressor through the recirculation flow path RP, is compressed again by the compressor, and is supplied to the combustor, the time required to warm up the catalyst CCT to a predetermined temperature or more is shortened. It

When it is detected that the temperature of the combustion gas measured by the temperature detecting means TC exceeds a predetermined temperature, the control unit CNT issues a "close" command to the fuel injection valve INJ for several hundreds of milliseconds. Output and stop flame combustion. At the same time, the control unit CNT outputs an “open” command to the exhaust cutoff valve EV and a “closed” command to the recirculation cutoff valve RV, and shifts to a steady operation state.

FIG. 2 is a gas flow chart in the steady operation state of the first embodiment, in which fuel gas or exhaust gas flows through the flow path shown by the thick line. In the first embodiment, since the combustion gas is recirculated before flowing into the output turbine, the temperature of the catalyst CCT can be rapidly raised, but so-called self-driving cannot be performed and the operation needs to be continued by the starter. There is.

FIG. 3 is a block diagram of the second embodiment, in which exhaust gas after working in the output turbine is recirculated. In the second embodiment, it is possible to replace the recirculation cutoff valve RV and the exhaust cutoff valve EV in the first embodiment with a single three-way valve TV. That is, the three-way valve TV is installed in the exhaust flow passage between the output turbine GT and the gate catalyst CT, the inlet port is the output turbine, the first outlet port is the return passage RP, the second outlet port is It is connected to the exhaust passage EP.

FIG. 3 shows the gas flow at the time of startup of the second embodiment, in which the exhaust gas working in the output turbine GT passes from the inlet port of the three-way valve TV to the first outlet port,
It is recirculated to the intake port of the compressor via the recirculation flow path RP. FIG. 4 is a gas flow diagram in the steady operation state of the second embodiment, in which after the combustion gas temperature at the combustor CC outlet reaches a predetermined temperature or higher, the three-way valve TV is switched to exhaust gas as a catalyst Release via CT.

In the second embodiment, the operation by the starter is short, but the temperature of the gas recirculated to the intake of the compressor CP is lowered, so that the time required for warming up the catalyst CT is long. 5 and 6 are views showing first and second modification examples of the installation position of the three-way valve TV in the second embodiment, and FIG. 5 is a three-way valve TV at the outlet of the issue catalyst CT.
6 shows the case where the three-way valve TV is provided at the outlet of the heat exchanger HX.

In the first modified example of FIG. 5, the opening catalyst C is used.
It is possible to warm up T, but the temperature of the recirculated gas is the second
Since the temperature is lower than that of the above example, the time required for warming up the catalyst CCT becomes somewhat longer. In the second modified example of FIG. 6, it is possible to warm up the number catalyst CT and the heat exchanger HX, but the time required for warming up the catalyst CCT becomes longer.

[0019]

According to the gas turbine using the catalytic combustor according to the present invention, since the combustion gas or the exhaust gas is recirculated to the intake port of the compressor from the passage of the combustor wake at the time of starting the gas turbine, It is possible to shorten the warm-up time of the catalyst in the catalyst combustor.

Further, the heat exchanger does not need to be warmed up again when it is warmed up by the hot compressed air and enters the steady operation state, so that the fuel consumption can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a gas flow chart in a steady operation state of the first embodiment.

FIG. 3 is a configuration diagram of a second embodiment.

FIG. 4 is a gas flow chart in a steady operation state of the second embodiment.

FIG. 5 is a configuration diagram of a first modification of the second embodiment.

FIG. 6 is a configuration diagram of a second modification of the second embodiment.

[Explanation of symbols]

 CP ... Compressor GT ... Output turbine CC ... Combustor HX ... Heat exchanger L ... Load S ... Shaft CT ... Nozzle catalyst RV ... Reflux shutoff valve RP ... Reflux passage EV ... Exhaust shutoff valve EP ... Exhaust passage CNT ... Control Department

Claims (1)

[Claims] 1. A gas turbine using a catalytic combustor as a combustor, the catalytic combustor having a heat exchanger for heating compressed air with exhaust gas of an output turbine, comprising: A gas turbine using a catalytic combustor, characterized in that a recirculation flow path is installed to recirculate the gas from the flow path downstream of the combustor to the intake port of the compressor when the temperature is below the activation temperature.