JPS633298A - Power plant waste-heat recovery device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a power generation membrane R using a condensing turbine, and in particular, the present invention relates to a power generating membrane R using a condensing turbine. The present invention relates to a power plant waste heat recovery device suitable for supplying water as water.

[Conventional technology]

FIG. 6 shows an example of an unstructured configuration of a conventional turbine power generation facility. In the figure, 1 is a steam generator such as Atomic 1, 2 is a main steam pipe, 3 is a cross-around pipe from a high-pressure turbine 4 to a low-pressure turbine 5, 6 is a generator, 7 is a high-pressure turbine extraction pipe, and 8 is its extraction air. 9 is a water supply pipe, 1o is a low-pressure turbine bleed air pipe, 11 is a low-pressure feed water heater that heats the feed water by the bleed air, 12 is a water feed pump, and 13 is a recovery water heater. water container 14
cooling water piping, 15 is a circulation pump for this cooling water, 16
is a condensate pump that sends condensate from the condenser to the feedwater heater.

In such a system, steam flowing into the steam turbine 5 expands inside the turbine, and its work rotates the generator 6 to generate electricity. The steam expanded to a turbine exhaust pressure close to vacuum flows into the condenser 14, where it is cooled and becomes condensed water. The heat contained in the steam is released into condenser cooling water such as seawater. Even in state-of-the-art power generation equipment, this amount of heat radiation accounts for more than 50% of the amount of heat generated by steam, resulting in a large loss.

Furthermore, in nuclear power generation facilities, as mentioned above, the current situation is that more than 50% of the heat generated in the nuclear reactor is discharged from the condenser into the sea. Particularly in the case of nuclear power generation, this waste heat is considered as an impact of heated wastewater on the environment, and is one of the constraints on location. Various methods of recovering heat discharged outside the system from nuclear power generation equipment are being studied.

However, even with the newest technology,
As shown in No. 494, the amount of waste heat recovered from reactor coolant purification equipment, etc. is less than 1% of the total, and the amount of waste heat recovered from the main condenser, which accounts for more than 50% of the total, is It remains uncollected.

[Problem that the invention seeks to solve]

In the above conventional technology, the temperature of the seawater discharged from the main condenser is kept at a low temperature of 40 degrees Celsius or less due to environmental considerations.
Waste heat cannot be used for other equipment, and more than 50% of the heat ends up being discarded into seawater (cooling water).

On the other hand, if you try to raise the temperature of this cooling water, the degree of vacuum in the condenser will deteriorate, which will reduce the efficiency of the turbine generator, and the disadvantage is that waste heat recovery will be a disadvantage compared to the original purpose of power generation. there were.

An object of the present invention is to provide a power plant waste heat recovery device that recovers waste heat that is currently discharged from a condenser to seawater or the like without reducing the efficiency of a turbine-f@ma.

[Means for solving problems]

In order to achieve the above object, the present invention makes the cooling water supply piping to the condenser a closed loop, and installs a cooling water heating heat exchanger using turbine extraction air as a heating source downstream of the condenser in the cooling water supply piping. A hot water supply heat exchanger is installed on the side, and a hot water supply heat exchanger is installed downstream of the hot water supply heat exchanger, which uses the cooling water heated by this heat exchanger as a heating source to heat the water supplied outside the system. A waste heat recovery system for a power plant is installed further downstream with a ring water pump that sends water back to the condenser.

[Effect]

The cooling water at the outlet of the main condenser is about 40°C, but if it is heated by the bleed air from the turbine 5@electric machine.

The temperature can be raised to about 100''C. If this hot water is supplied to the heat exchanger on the hot water supply side, the heat is recovered.

The cooling water whose heat has been recovered, that is, the cooling water whose temperature has decreased, is again supplied to the condenser as cooling water by the @ring pump. As a result, more than 50% of the heat that is wasted as waste heat in conventional power generation equipment will be recovered and effectively used.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Steam generated in a steam generator, for example, a nuclear reactor 1, performs work in a high pressure turbine 4 and a low pressure turbine 5, is cooled in a main condenser 14, and becomes condensed water. In conventional power generation equipment, this cooling is performed using seawater.

In contrast, in the present invention, the cooling water distribution line f13 that supplies cooling water to the main condenser 14 is provided with a cooling water heating heat exchanger 19,
The heated cooling water is used in factories or homes. The heated steam is extracted steam from the low-pressure turbine 5 and is supplied to the heating heat exchanger 19 through the steam supply pipe 17, and the condensed water after heating is recovered to the main condenser 14 through the heated steam return pipe 20. do.

In this example, the temperature of the condenser outlet cooling water is raised to about 100°C by the bleed air from the turbine generator, and after the water to be supplied to factories and homes outside the system has been heated, the bleed air is also recovered to the main condenser. Therefore, the recovery rate is high.

In other words, more than 50% of the calorific value of the power generation equipment, which was conventionally discarded, can be recovered. Therefore, the efficiency of conventional plants, which was about 45% at best, will increase to 90%. In addition, the present invention, which has a closed-loop condensate cooling system, eliminates the need for large-scale discharge of waste heat into seawater, allowing power generation equipment to be located on the coast! ! ! There is no longer a restriction that the equipment be placed in contact with the equipment, and it becomes possible to install it inland. In addition, the cooling tower that was installed in inland power generation facilities to release waste heat is no longer necessary, which is effective in reducing equipment costs.

Another embodiment is shown in FIG. 2. In this embodiment, the heat source of the heating heat exchanger 19 is high pressure turbine extracted steam, and a steam supply pipe 23 is installed.

As a result, the supply water to the hot water supply heat exchanger 20 is reduced to 20%.
It can be raised to about 0°C. Therefore, this embodiment is effective when high-temperature water or steam is required in factories, homes, etc.

Another embodiment is shown in FIG. 3. This embodiment has the same configuration as that in FIG. 1, with a flow rate control valve 18 installed in the steam supply pipe 17 to the cooling water heating heat exchanger 19. . As a result, the temperature of the water supplied to the hot water supply heat exchanger 22 is reduced to 100%.
It can be adjusted from about ℃ to about 50℃.

Another embodiment is shown in FIG. This embodiment has the same configuration as that shown in FIG. 2, with a flow rate control valve 24 installed in the steam supply pipe 23 to the cooling water heating heat exchanger 19. As a result, the temperature of the water supplied to the hot water supply heat exchanger 20 is increased to 200.
It can be adjusted from about ℃ to about 50℃.

Another embodiment is shown in FIG. In this embodiment, the heat source of the heating heat exchanger 19 is both the extracted steam of the high-pressure turbine 4 and the extracted steam of the low-pressure turbine 5, and a flow control valve 18.24 is installed in each supply pipe 17.23. It is something. As a result, among the temperatures supplied to the hot water supply heat exchanger 20, from about 50°C to about 100°C is used as extracted steam from the low-pressure turbine 5, and from about 100 aC to about 200°C is used as extracted steam from the high-pressure turbine 4. Since they can be shared, there is no need to widen the control range of the flow rate control valves 18 and 19, and the valve structure and control method become simple.

In each of the above embodiments, the steam generator is described as a nuclear reactor, but it is obvious that the present invention can also be applied to condensing turbines using other heat sources such as thermal power plants.

〔Effect of the invention〕

According to the present invention, most of the 50% or more heat that was wasted in conventional steam turbine power generation equipment using condensing turbines can be recovered and effectively used, increasing the thermal efficiency of the entire power generation equipment to around 90%. It's expensive.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing an embodiment of a nuclear power plant equipped with power plant waste heat recovery equipment according to the present invention, and Figs. 2 to 5 are system diagrams showing other embodiments of the present invention. figure,
FIG. 6 is a system diagram showing an example of a conventional turbine power generation plant. DESCRIPTION OF SYMBOLS 1... Steam generator, 2... Main steam piping, 3... Cross-around pipe, 4... High pressure turbine, 5... Low pressure turbine, 6... Generator, 7... High pressure turbine extraction piping , 8... High pressure water supply heater, 9... Water supply piping, 10
...Low pressure turbine extraction piping, 11...Low pressure feed water heater, 12... Water supply pump, 13... Cooling water pipe, 1
4... Condenser, 15... Circulating water pump, 16...
Condensate pump, 17...Low pressure extraction air supply piping, 18...
Flow rate control valve, 19... Heat exchanger for heating cooling water, 20.
・・Heating steam drain piping, 21 ・・Hot water supply piping, 2
2... Heat exchanger for hot water supply, 23... High pressure extraction air supply piping, 24... Flow rate control valve.

Claims (1)

[Claims] 1. In a power plant waste heat recovery device that recovers waste heat discharged from a condenser of a turbine power generation facility using steam as a driving source, a closed loop is formed and the waste heat is cooled to the condenser. A cooling water pipe that supplies water, a cooling water heating heat exchanger that is installed downstream of the condenser in the cooling water pipe and heats the cooling water using the air extracted from the turbine as a heat source, and A bleed air supply pipe that supplies the heat exchanger; a hot water supply heat exchanger that is installed downstream of the heat exchanger and uses heated cooling water as a heat source to heat water that is supplied outside the system; A power plant waste heat recovery device characterized by comprising a circulating water pump that is installed downstream of the circulating water pump and sends the cooling water that has undergone heat exchange with water outside the system to the condenser again. 2. A power plant waste heat recovery device according to claim 1, wherein the extraction air supply piping is a piping that supplies extraction air from a low-pressure turbine. 3. The power plant heat recovery device according to claim 1, wherein the bleed air supply pipe is a pipe that supplies bleed air from a high-pressure turbine. 4. A power plant waste heat recovery device according to claim 1, wherein the extraction air supply piping is a piping that supplies extraction air from a low pressure turbine and a high pressure turbine. 5. A power plant waste heat recovery device according to any one of claims 2 to 4, wherein the bleed air supply pipe is provided with a flow rate control valve.