JPS61272407A - Heat recovery device in gas turbine - Google Patents

Abstract

PURPOSE:To improve thermal efficiency in the whole plant, by providing a means, which reduces a pressure of heating steam in a methanol resolving reactor in a generating plant, while supplying said pressure reduced steam to a steam turbine. CONSTITUTION:An indirectly heat exchanging type methanol cracking generating plant provides a methanol resolving reactor 1, evaporator 2, superheater 3, economizer 5, feed water pump 8 and a suction drum 9. The plant, reducing a pressure of heating steam in the methanol resolving reactor 1 to be controlled to the pressure equal to that of a high pressure main steam line, enables the steam to be supplied not only to a high pressure turbine HT in the own line but also to a high pressure turbine ht in the other line. In this way, a heat recovery device, improving an output of the steam turbine, enables thermal efficiency of the whole plant to be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas turbine heat recovery device, and is used in the technical field of effectively utilizing generated steam and improving the thermal efficiency of the entire plant.

In the methanol cracking reactor of a gas turbine in a conventional power plant, methanol is used in a liquid state when the gas turbine is started, and it is necessary to switch over to cracked gas only after a certain turbine load is reached.

In an indirect heat exchanger that uses a tandem exhaust gas boiler to recover heat, the exhaust gas from the gas turbine is recovered by each element.

Therefore, high-temperature, high-pressure steam is also generated from the heater for the methanol decomposition reactor.

Therefore, until now, there has been no study on how to effectively utilize the generated steam before switching the gas turbine fuel from methanol to cracked gas.

Problems to be Solved by the Invention The present invention aims to improve the thermal efficiency of the entire plant by effectively utilizing the high-temperature, high-pressure steam generated from the heater of the methanol decomposition reactor.

Means for Solving the Problems The present invention takes the following measures in order to solve the above-mentioned problems. That is, it is equipped with a means for reducing the pressure of the heating steam of the methanol decomposition reactor in the power generation plant, and this reduced pressure steam is controlled to the same pressure as the high pressure main steam system and is supplied to the steam turbine.

According to the means described above, by reducing the pressure of the steam generated from the cracking reactor and supplying it to the steam turbine, it is possible to increase the output of the steam turbine commensurate with the supplied amount.

Embodiment Next, an embodiment of the present invention will be described with reference to FIG. 1, which shows a system in which the latent heat of condensation of steam is used, and FIG. 2, which shows a system in which a steam circulation system is used.

In both figures, 1 is the methanol decomposition reactor, 2 is the evaporator, 3 is the superheater, 4 is the circulation pump, 5 is the economizer, 6 is the high pressure main steam system, 7 is the low pressure main steam system, and 8 is the water supply. pump, 9 is a suction drum, and in the arrows indicating the flow direction of the pipe line, gt is to the gas turbine, ms is from the methanol evaporator, ac is to the condenser, fp is from the feed pump, h
t goes to the high pressure steam turbine of another series, HT goes to the high pressure steam turbine, 7t goes to the low pressure steam turbine of another series, LT
indicates to the low pressure steam turbine.

The points of this system are as follows.

a) By reducing the pressure of the heating steam in the methanol decomposition reactor and controlling it to the same pressure as the high-pressure main steam system, it is possible to supply steam not only to the high-pressure turbine in the own system, but also to high-pressure turbines in other systems. can.

b) If there is excess steam in the high pressure steam system, steam can also be supplied to the low pressure steam turbine via the pressure reducing valve.

The temperature control shown in Figure 1 is a superheater bypass method in which temperature control is performed by mixing nearly saturated steam with the steam at the outlet of the superheater 3.
The same applies to the method of installing a desuperheater during this time.

Effects of the Invention When switching the gas turbine fuel from methanol to cracked gas, the steam for heating the cracking reactor is supplied to the steam turbine to improve the output of the steam system, contributing to improving plant efficiency.

[Brief explanation of drawings]

FIG. 1 is a system diagram according to the present invention in the case of using the latent heat of condensation of steam, and FIG. 2 is a system diagram according to the present invention in the case of a steam circulation system. 1. Methanol decomposition reactor, 2. Evaporator, 3. Superheater, 4. Circulation pump, 5. Economizer, 6. High pressure main steam system, 7. Low pressure main steam system, 8・・Water supply pump,
9. Suction drum. C and other names)

Claims (1)

[Claims] A gas system that is equipped with a means to reduce the pressure of the heating steam of the methanol decomposition reactor in an indirect heat exchange methanol cracking power plant, and controls this reduced pressure steam to the same pressure as the high-pressure main steam system before supplying it to the steam turbine. Turbine heat recovery equipment.