JPH0281907A - Steam supply and power generating plant - Google Patents

Abstract

PURPOSE:To enable reduction in the loss of thermal energy by providing such a constitution as selecting the extraction point from a steam turbine and making the control of the temperature of a heating water possible. CONSTITUTION:Three heaters 11-13 having different extraction points for heating water by using the extracted steam from a steam turbine 2 are connected to the steam turbine 2. The heaters 11-13 are provided with extraction stop valves 14-16 for stopping the extracted steam to each heater 11-13 according to the conditions, respectively. A temperature control device 30 controls the extraction stop valves 14-16 according to the temperatures in the points A, B, the inside pressure in the heaters 11, 12, and load of the turbine 2, and a required heat load. Hence, the extraction point is selected to regulate the temperature of the heating water. Thus, the pressure tightening in the pressure regulation can be eliminated, so that the loss of thermal energy in the whole plant can be reduced.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a combined heat and power generation plant.

(Conventional technology) Conventionally, cogeneration power plants have mainly used industrial steam turbines and the like to supply steam to factories as a thermal energy source, and the pressure and temperature of the supplied steam can be adjusted inside and outside the turbine. It was regulated by a control device.

(Problem to be Solved by the Invention) However, in the conventional combined heat and power generation plant described above, a pressure loss is caused in the main stream of steam (steam used for power generation) or in the bleed steam, resulting in a thermal energy loss. I will invite you.

The present invention has been made in response to such conventional circumstances,
The aim is to provide a combined heat and power generation plant that can reduce thermal energy losses, generate electricity more efficiently, and supply stable thermal energy according to the heat load. be.

[Structure of the Invention] (Means for Solving the Problems) That is, the combined heat and power generation plant of the present invention includes a steam turbine that generates power using steam generated by a steam generator, and a steam turbine that uses different oils and gases in the steam turbine. a plurality of heaters each heating water, which is a heat medium, using steam from a point and supplying the thermal energy of the steam in the form of heated water; It is characterized by being configured so that the temperature of the water can be controlled.

(Function) In the combined heat and power generation plant of the present invention having the above configuration, steam is not used directly as the thermal energy supply medium, but steam from different extraction points of the steam turbine is used by a plurality of heaters to generate water as a heat medium, respectively. and supplies the thermal energy of the steam in the form of heated water. Then, the internal pressure (bleed pressure) of each heater is measured, and in order to reach the target heated water temperature, the heaters that bleed air from the high bleed point of the steam turbine are activated or deactivated. Alternatively, the temperature of the heated water is adjusted by selecting the bleed point by switching the bleed route or the like.

Therefore, by eliminating the pressure bar for pressure adjustment,
It is possible to reduce thermal energy loss throughout the plant.

In addition, in operating ranges where the temperature cannot be controlled by the above operations, it is recommended to use a system that bypasses the heater group and mix water that has bypassed the heaters, or to use a heater using a heat source other than steam (boiler, exhaust gas, etc.). A heat recovery boiler (heat recovery boiler) is installed to adjust the temperature by heating.

(Example) Hereinafter, details of the combined heat and power generation plant of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a combined heat and power generation plant according to an embodiment of the present invention, and the system on the power generation plant side is configured in the same way as a normal power generation plant.

That is, the steam generated in the steam boiler 1 rotates the steam turbine 2 and the power generator 3 to generate electricity, and the steam that rotates the steam turbine 2 is cooled in the condenser 4 and returned to water, and is then turned into steam again. It is configured to be sent to boiler 1.

On the other hand, the system that supplies thermal energy extracts heating steam from the steam turbine 2 and heats water, which is a heat medium, so as to supply the thermal energy required by the thermal load 10 as follows. It is configured.

That is, three heaters 11, 12, and 13 are connected to the steam turbine 2, each having a different extraction point and heating water using the extracted steam from the steam turbine 2. At 12.13, there are bleed stop valves 14, 15, and 14, which stop the bleed steam to each heater depending on the situation.
16 are provided respectively. In addition, the heater 11
．． 12.13 bypass the water and heater 11.1
A bypass line 17 for mixing the water heated by 2.13 on the secondary side of the heater and adjusting the temperature, and a bypass control valve 18 for controlling the flow rate of the bypass line 17 are provided. Furthermore, in case a temperature (thermal energy) higher than the temperature obtained by the heater 11, 12, 13 is required, a heating boiler 19 and a heating boiler bypass valve 20 are inserted.
A heating boiler bypass line 21 is provided to bypass the boiler 9 and flow heated water. In addition, in the figure, numerals 22 and 23 indicate a pump and a drain pump, respectively. Further, a system (not shown) is provided for returning the heated steam condensed by the heaters 11, 12, 13 to the power generation plant side and recovering thermal energy.

The system that supplies thermal energy with the above configuration is based on the temperature at the two points As shown in the figure, the internal pressure (extraction pressure) of heating 2; The temperature control device 30 controls the bleed stop valve 14, 15, the bypass control valve 18, the heating boiler 19, and the heating boiler bypass valve 20 according to the heat load as follows.

First, since the temperature at point A is directly affected by the internal pressure of the heater 11, it is determined whether the heaters 11 and 12 are activated or not depending on the internal pressure, and the bleed stop valve .12 opens and closes. That is, when the load on the steam turbine 2 side is high and the heat load is also large, the heater 12
．． 13 is in operation, and the heater 11 is operated by the bleed stop valve 1.
4 has been closed and is considered ineffective.

Even when only these two heaters 12 and 13 are in operation, the temperature at point A changes as the internal pressure of the heater 12 fluctuates due to a slight increase or decrease in the load on the steam turbine 2 side. Therefore, in order to control the heated water temperature to the target value, the bypass control valve 18 is adjusted to adjust the amount of low temperature water mixed.

If the load on the steam turbine 2 is significantly reduced in such a state, the internal pressure of the heaters 12 and 13 will decrease, and even by fully closing the bypass control valve 18, the temperature at point A will decrease. . Therefore, in order to operate the heater 11 which is bleeding air at a pressure higher than the bleed point of the heater 12,
Open the bleed stop valve 14. As a result, the water is heated by the heater 11 having a high internal pressure, and a high temperature is obtained. At the same time, the bypass control valve 18 is activated again to lower the heated water temperature to the target temperature.

Further, when the load on the steam turbine 2 is constant and the heat load decreases, the pressure inside each heater increases and the heated water temperature increases. This is controlled by the bypass regulating valve 18, but if the temperature exceeds the control range, the highest pressure heater (heater 11) that is in operation is deactivated and the temperature is lowered to the target temperature.

Furthermore, if a higher heat load is required than the capacity of this heater 11, 12, 13 and heating water of a higher temperature is required, the heating boiler 19 provided on the secondary side of the heating device is used to heat the water. to raise the temperature to the target temperature.

In the cogeneration power generation plant of this embodiment described above, compared to the case where the extraction pressure is adjusted inside and outside of the steam turbine 2 body, the loss of thermal energy of the entire plant is achieved by eliminating the pressure tightening of the pressure adjustment. It is possible to reduce the

FIG. 2 shows a combined heat and power generation plant according to another embodiment. This realizes the functions of the heaters 11 and 12 in operation and inaction.

That is, in a state where the oil/air switching valve 41.43 is open and the bleed air switching valve 40.42 is closed, when the bleed air pressure decreases due to a decrease in the load of the steam turbine 2, etc., and the heated water temperature falls, the bleed air switching valve 41. .43 is closed, and at the same time the bleed air switching valve 40.42 is opened to bleed steam from a higher bleed point and maintain the heated water temperature.The other configurations and functions are the same as in the previous embodiment.

FIG. 3 shows a combined heat and power generation plant according to yet another embodiment, in which a highest pressure heater 11 is installed in the heating bypass line 17 of the previous embodiment shown in FIG. It is something that

That is, in the above embodiment, the effect of the bypass system is as follows.
The temperature was lowered by mixing unheated water with the excessively heated water, but in this embodiment, the highest pressure heater 11 was activated and deactivated. The bypass system has two functions: temperature reduction and heating, to control the heated water temperature. Note that the other configurations and operations are the same as those of the above-described embodiment shown in FIG.

[Effects of the Invention] As explained above, the combined heat and power generation plant of the present invention can reduce thermal energy loss, perform power generation more efficiently, and It can supply stable thermal energy.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a cogeneration plant according to one embodiment of the present invention, Fig. 2 is a block diagram showing a cogeneration plant according to another embodiment, and Fig. 3 is a cogeneration diagram showing a cogeneration plant according to another embodiment. FIG. 1 is a configuration diagram showing a power generation plant. 1・・・・・・・・・・・・・・・・・・Steam boiler 2・・・・・・・・・・・・・・・Steam turbine 3・・・・・・・・・......... Generator 11~
13...Heater 14-16...Bleed stop valve

Claims (1)

[Claims] (1) A steam turbine that generates electricity using steam generated by a steam generator; and a steam turbine that uses steam from different extraction points of the steam turbine to heat water, which is a heat medium, and heat the thermal energy of the steam. A cogeneration power generation plant comprising: a plurality of heaters that supply water in the form of water, and configured to be able to control the temperature of the heated water by selecting an extraction point from the steam turbine.