JPH01310112A - Cogenerating plant using combustion engine - Google Patents

Abstract

PURPOSE:To improve efficiency by arranging a back pressure steam turbine coaxial with a combustion engine generator, and connecting a generating steam line and a steam exhaust line to the back pressure steam turbine. CONSTITUTION:A back pressure steam turbine 13 is arranged coaxial with a gas turbine generator 6, and the back pressure steam turbine 13 is connected with a generating steam line 12 and a steam exhaust line 14. Steam of an exhaust heat recovering boiler 9 is sufficiently utilized on the back pressure steam turbine 13 for becoming in low pressure, and the steam is exhausted to an outlet of the exhaust heat recovering boiler 9, therefore it is possible that a high efficiency plant with a simple apparatus is constituted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to combustion engines such as gas turbines and diesel engines (in this specification, gas turbines, diesel engines, etc. are collectively referred to as combustion engines). Regarding a combined heat and power plant using.

[Conventional technology]

In conventional gas turbine combined heat and power plants, combinations of gas turbines and extraction condensing steam turbines exist. That is, an exhaust heat recovery boiler is installed on the exhaust side of the gas turbine, and the generated steam is guided to the extraction condensation turbine to generate electricity, and the generated steam is also sent to a heat load supply source different from the extraction condensation turbine. There is a system that has made this supply possible.

[Problem to be solved by the invention]

The combination of a gas turbine and an extraction-condensing steam turbine in the conventional combined heat and power system described above is expensive because it includes a condenser system, a seawater circulation system, etc. in addition to the steam turbine, and this is not recommended for small-scale combined heat and power plants. This point was a weakness and it was difficult to adopt it.

Therefore, in small-scale combined heat and power plants, it is necessary to reduce costs by combining back pressure steam turbines that do not require these systems.

In addition, there is a conventional technology known as a chain cycle in which steam generated in an exhaust gas boiler is introduced into a gas turbine to balance heat and electricity, but when the required steam power is at high pressure, the pressure is reduced and the steam is introduced into the gas turbine. This results in large losses and poor efficiency. Furthermore, in the case of low pressure, there may be restrictions due to the steam generation conditions in the exhaust gas boiler, such as the inability to introduce steam to the gas turbine.

The present invention aims to solve these problems.

[Means to solve the problem]

The present invention provides a back-pressure steam turbine that does not require a condenser system, a seawater circulation system, etc. and can handle any steam conditions in a combined heat and power plant using a gas turbine, diesel engine, etc. an exhaust heat recovery boiler disposed coaxially with the generator and provided downstream of the exhaust gas of the combustion engine; a line for introducing steam generated by the exhaust heat recovery boiler into the back pressure steam turbine; and an outlet of the back pressure steam turbine. A line for discharging the steam from the exhaust heat recovery boiler to an outlet duct of the exhaust heat recovery boiler and a line for introducing the steam generated by the exhaust heat recovery boiler to a heat load other than the back pressure steam turbine are provided.

[Effect]

In the present invention, the steam generated in the exhaust heat recovery boiler is
The power load and other heat loads are distributed to steam, air turbines, and other heat loads, but the back pressure steam turbine, which is placed coaxially with a combustion engine generator such as a gas turbine, has a condenser system and a seawater circulation system. , an inexpensive plant can be constructed without requiring a water supply system or the like. Furthermore, the back pressure steam turbine can be designed to be highly efficient depending on the steam conditions of the exhaust heat recovery boiler installed downstream of the gas turbine.

Furthermore, the back pressure steam turbine can sufficiently recover the energy of the steam introduced from the heat recovery boiler, and the resulting low pressure exhaust gas is directly discharged to the outlet duct of the heat recovery boiler. This increases the thermal efficiency of the plant and simplifies the equipment.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.

Reference numeral 5 denotes a gas turbine, in which combustion air is introduced from the air inlet l of the compressor 2, compressed by the compressor 2, and then delivered to the combustor 4. At the same time, the fuel is supplied to the combustor 4 and combusted, becoming a high-temperature, high-pressure combustion gas that is guided to the gas turbine 5 to perform work and rotate the coaxially connected generator 6 to obtain electrical output. On the other hand, the combustion exhaust gas exiting the gas turbine 5 is led to an exhaust heat recovery boiler 9, where heat exchange is performed.

As shown in Fig. 1, the exhaust heat recovery boiler 9 is equipped with a energy saver, an evaporator, and a superheater, and is supplied with water by a water supply pump. is distributed to a heat source steam supply line 11 connected to a heat load (not shown) and a power generation steam 2-inch line according to the thermoelectric and S lances. At this time, the auxiliary fuel 8 may be combusted in the duct nozzle 7 for the purpose of increasing the amount of steam or increasing the steam temperature.

The back pressure steam turbine 13 is installed coaxially with the gas turbine generator 6, and the power generation steam line 12 is connected to the back pressure steam turbine 13, so that the steam from the exhaust heat recovery boiler 9 is supplied with the same back pressure. It is introduced into a steam turbine and performs work, and an electric output is obtained from the generator 6. The low-pressure steam at the outlet of the back pressure steam turbine 13 is discharged through the steam exhaust line 14 to the exhaust gas duct 15 of the exhaust heat recovery boiler, and then to the chimney 1.
Leads to 6.

Note that the distribution of steam between the back pressure steam turbine 13 and other heat loads described above is determined by the values of the required electric power load and other heat loads, and is controlled by, for example, the governor of the back pressure steam turbine 13. This can be done by adjusting the amount of steam.

As described above, in this embodiment, the exhaust gas of the gas turbine is used to generate steam in the exhaust heat recovery boiler 9 and this is used for power generation and other heat loads. By arranging the back pressure steam turbine 13 coaxially with the generator 6, which does not require
An inexpensive plant can be constructed.

Furthermore, in the back pressure steam turbine 13, the steam generated by the exhaust heat recovery boiler 9 is fully utilized to lower the pressure of the exhaust gas, and the exhaust gas thus reduced in pressure is directly sent to the exhaust duct 15 of the exhaust heat recovery boiler 9. By discharging it, the equipment becomes simpler and construction costs can be lowered.

Furthermore, the back pressure steam turbine 13 includes a gas turbine 5
According to the steam conditions of the waste heat recovery boiler that receives the exhaust gas, a highly efficient one can be adopted, and the thermal efficiency of the plant can be improved.

〔Effect of the invention〕

As explained above, the present invention uses a back-pressure steam turbine that does not require a condenser system, a seawater circulation system, etc., so it is possible to construct an inexpensive plant and is suitable for the steam conditions generated by an exhaust heat recovery boiler. In addition, the steam from the heat recovery boiler is sufficiently utilized by the back pressure steam turbine to become low pressure, which is then discharged to the outlet duct of the heat recovery boiler, so that the equipment is A simple and highly efficient plant can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a combined heat and power plant using a gas turbine generator as an embodiment of the present invention. 2... Compressor, 5... Gas turbine, 6
... Generator, 7... Duct burner, 9.
...Exhaust heat recovery boiler, 11...Heat source steam line, 12
...Steam line for power generation, 13...Back pressure steam turbine, 14...Steam exhaust line, 15...Exhaust gas duct of exhaust heat recovery boiler, 16...
chimney.

Claims (1)

[Claims] A combustion engine generator, a back pressure steam turbine arranged coaxially with the generator, an exhaust heat recovery boiler installed in the wake of the exhaust of the combustion engine, and the steam generated by the exhaust heat recovery boiler is transferred to the back pressure steam turbine. A line for introducing the steam at the outlet of the back pressure steam turbine to an outlet duct of the exhaust heat recovery boiler, and a line for introducing the steam generated by the exhaust heat recovery boiler to a heat load different from the back pressure steam turbine. A combined heat and power plant that uses a combustion engine.