JPH08135411A - Control device of exhaust heat using power plant - Google Patents

Abstract

PURPOSE: To constantly provide stable generator output by controlling a flow rate of steam led to a steam turbine so that the output of a generator becomes a previously specified power setting value by separating exhaust heat steam introduced in a steam separator of an exhaust heat using power plant. CONSTITUTION: Steam is separated by a steam separator 3 generates electric power by rotating a generator 10 directly connected to a steam turbine 9 through an exhaust heat steam flow passage 5. At this time, a steam flow rate is opening-controlled by a flow rate control valve 8 in accordance with a steam flow rate detected by a flow rate detector 7, and steam pressure is opening-controlled by a pressure control valve 29 in accordance with steam turbine inlet temperature detected by a pressure detector 6. Additionally, an exhaust heat hot water level of the steam separator 3 is opening-controlled by a level control valve 30 in accordance with an exhaust heat hot water level detected by a level detector 4, and pressure in the steam separator 3 is precedently controlled in a direction not to reduce pressure in the steam separator 3 at the time when the steam flow rate is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a heat-generating power plant which uses exhaust heat obtained from waste heat steam of an industrial plant or underground steam.

[0002]

2. Description of the Related Art In general, there are various special power generation systems in addition to systems such as thermal power generation, hydraulic power generation, and nuclear power generation as power generation systems. As one of the special power generation methods, there is a power generation method that uses exhaust heat obtained from an industrial plant or underground.

[0003] Such an exhaust heat utilization power generation system, like the thermal power generation, drives a steam turbine with steam and rotates a generator directly connected to the steam turbine to generate power, but compared with thermal power generation. Since the fuel cost required for rotating a steam turbine can be greatly saved, in recent years, attention has been paid to the utilization of resources.

In such control of a power plant utilizing exhaust heat, the flow rate of exhaust heat is not always fixed and therefore, no special control is performed on the flow rate of exhaust heat. That is, all the exhaust heat obtained from an industrial plant or the like is used to drive the steam turbine, and basically the maximum electric power operation is performed.

[0005]

However, in such a control system for an exhaust heat utilization power plant, when the exhaust heat flow rate or exhaust heat temperature from an industrial plant or the like changes, the generator output also immediately changes. However, there is a drawback that it is a control that leaves it to nothing.

An object of the present invention is to provide a control device for an exhaust heat utilization power plant that can always obtain a stable generator output regardless of changes in exhaust heat flow rate or exhaust heat temperature from an industrial plant or the like. There is.

[0007]

According to a first aspect of the present invention, there is provided a control device for an exhaust heat utilization power plant which controls a flow rate of steam flowing into a steam turbine so that a power output of the generator reaches a predetermined electric power set value. The control system and the steam separator that separates the exhaust heat steam into steam and hot water are controlled so that the hot water level becomes a preset value, and when the flow rate of steam flowing into the steam turbine increases, steam separation is performed. The hot water level control system of the steam separator that controls the hot water level of the steam separator in advance so that it does not rise, and the pressure inside the steam separator so that the steam pressure at the steam turbine inlet becomes a predetermined pressure set value. Of the steam turbine, and when the flow rate of steam entering the steam turbine increases, the internal pressure of the steam separator is controlled so as not to decrease, and when the hot water level of the steam separator increases, Reduce the pressure inside the separator And a steam pressure control system for proactively control the free direction.

According to a second aspect of the present invention, the hot water level of the waste heat treatment tank for storing the waste heat steam and the waste heat hot water from the steam separator is predetermined in the controller of the waste heat utilization power plant according to the first aspect. A water level control system for the exhaust heat treatment tank is added to control the exhaust water heat treatment tank so that the hot water level in the exhaust heat treatment tank does not increase when the steam separator hot water level increases. Are provided.

According to a third aspect of the present invention, in the control device of the waste heat utilization power plant according to the second aspect, the heat exchanger for exchanging the exhaust heat water guided from the exhaust heat treatment tank to the condenser with the cooling water from the cooling tower. The exhaust heat water outlet temperature at the exhaust heat treatment tank is controlled so as to reach a predetermined set value, and when the hot water level of the exhaust heat treatment tank is increased, the cooling water is controlled in advance so as to be increased, and the exhaust heat treatment tank is controlled. A cooling water temperature control system for the heat exchanger that controls the cooling water in the direction of increasing the cooling water in advance when the internal temperature becomes high is additionally provided.

According to a fourth aspect of the present invention, the control device of the waste heat utilization power plant according to the third aspect controls the water level of the condenser so as to reach a predetermined set value, and at the same time, the flow rate of steam introduced to the steam turbine. When the temperature rises, the water level in the condenser is controlled to decrease, and when the exhaust heat water outlet temperature in the heat exchanger rises, the water level is controlled not to decrease. An additional water level control system for the condenser is provided.

According to a fifth aspect of the present invention, the tank of the cooling tower for guiding the condensate from the condenser and circulating the cooling water to the heat exchanger is introduced into the control device of the waste heat utilization power plant according to the fourth aspect. Cooling is controlled so that the water level in the condenser reaches a preset value, and when the water level in the condenser rises, the water level in the tank of the cooling tower does not rise in advance. A water level control system for the tower is additionally provided.

According to a sixth aspect of the present invention, the controller of the waste heat utilization power plant according to the fifth aspect controls the temperature in the tank unit of the cooling tower so as to reach a predetermined set value, and also controls the condenser. When the water level rises, the temperature inside the tank unit of the cooling tower is controlled in advance so that it does not rise, and when the temperature of the cooling water from the heat exchanger and the temperature inside the condenser are high, the temperature is controlled. In order to prevent the temperature inside the tank unit of the cooling tower from rising based on the higher one, an inside temperature control system of the cooling tower is additionally provided.

[0013]

The exhaust heat steam that has flowed into the steam separator of the waste heat utilization power plant is separated into steam and hot water, and the steam is guided to the steam turbine. The flow rate of steam introduced into the steam turbine is controlled by the steam flow rate control system so that the output of the generator reaches a preset electric power setting value.

The hot water level of the steam separator is controlled by the hot water level control system of the steam separator to a preset value, and when the flow rate of steam flowing into the steam turbine increases. The hot water level of the steam separator is controlled in advance so that it does not rise.

Further, the steam pressure at the inlet of the steam turbine is controlled by controlling the internal pressure of the steam separator so as to reach a predetermined pressure set value by the steam pressure control system. In this case, the steam pressure control system proactively controls the internal pressure of the steam separator when the flow rate of steam flowing into the steam turbine increases, and the hot water level of the steam separator increases. In this case, the internal pressure of the steam separator is controlled in advance so as not to decrease it.

The exhaust heat steam and the exhaust hot water from the steam separator are guided to the exhaust heat treatment tank, and the hot water level of the exhaust heat treatment tank is set to a preset value by the water level control system of the exhaust heat treatment tank. Controlled to be. In this case, when the hot water level of the water level control system vapor separator of the exhaust heat treatment tank increases, the hot water level of the exhaust heat treatment tank is controlled so as not to increase.

Exhaust heat water from the exhaust heat treatment tank is guided to the condenser via the heat exchanger. This heat exchanger heats the waste heat water from the waste heat treatment tank with the cooling water from the cooling tower.The exhaust heat water outlet temperature in this heat exchanger is controlled by the cooling water temperature control system of the heat exchanger. And is controlled so as to reach a preset set value. In this case, when the hot water level of the exhaust heat treatment tank is increased, the cooling water temperature control system of the heat exchanger controls the cooling water in an increasing direction, and the internal temperature of the exhaust heat treatment tank is increased. If it does, the cooling water is controlled in advance in the direction of increasing it.

The water level level of the condenser is controlled by the water level control system of the condenser so as to reach a predetermined set value. In this case, the water level control system of the condenser controls the water level of the condenser to decrease when the steam flow rate leading to the steam turbine increases, and the exhaust heat water outlet of the heat exchanger When the temperature rises, the water level is controlled so that it does not decrease.

Condensed water from the condenser is introduced to the cooling tower, and cooling water circulated through the heat exchanger is introduced to the cooling tower. The water level level in the tank unit of the cooling tower is controlled by the water level control system of the cooling tower so as to reach a predetermined set value. In this case, the water level control system of the cooling tower controls in advance so that the water level in the tank unit of the cooling tower does not rise when the water level of the condenser rises.

The temperature inside the tank unit of the cooling tower is controlled to be a preset value by the inside temperature control system of the cooling tower. In this case, the internal temperature control system of the cooling tower controls in advance so that the temperature in the tank device of the cooling tower does not rise when the water level of the condenser rises, and When the temperature of the cooling water and the temperature inside the condenser are high, the temperature inside the tank unit of the cooling tower is controlled in advance based on the higher temperature.

[0021]

EXAMPLE An example of the present invention will be described below. FIG. 1 is a block diagram of the control device of the present invention. Also, FIG.
FIG. 1 is a configuration diagram of an exhaust heat utilization power plant to which the present invention is applied.

In FIG. 2, high temperature exhaust heat steam and exhaust heat hot water are pumped up by an exhaust heat pump 1 and input to a steam separator 3 through an exhaust heat supply passage 2. In the steam separator 3, steam and hot water are separated. The flow rate of the separated steam passes through the exhaust heat steam flow path 5 and is controlled by the flow rate control valve 8, and the steam turbine 9
Be led to. The steam turbine 9 rotates a generator 10 directly connected to it to generate electric power.

The steam that has finished its work in the steam turbine 9 flows through the exhaust heat flow passage 11 and is sent to the condenser 12 where it is cooled and condensed. The condensate flows through the condensate flow path 17 by the condensate pump 15 and is sent to the cooling tower 18. The condensate sent to the cooling tower 18 is cooled by the cooling fan 19 and stored in the tank of the cooling tower 18. The cooling water stored in the tank of the cooling tower 18 is sent to the heat exchanger 28 by the cooling water pump 26 via the cooling water replenishing flow path 25 and exchanges heat with the outlet waste heat water of the waste heat treatment tank 32. The heat-exchanged cooling water flows through the cooling flow path 36 and is sent to the cooling tower 18.

The hot water of the steam separator 3 flows through the exhaust heat treatment flow passage 31 and is sent to the exhaust heat treatment tank 32. The exhaust heat flows to the heat exchanger 28, exchanges heat with the cooling water supplied by the cooling water pump 26, and is sent to the condenser 12. On the other hand, the makeup water of the cooling tower 18 flows through the makeup water flow path 22 by the makeup water pump 24 and is supplied to the cooling tower 18.

Next, the control of the steam flow rate in the exhaust heat steam flow path 5 is performed by adjusting the opening degree of the flow rate control valve 8 by the control device 39 based on the steam flow rate detected by the flow rate detector 7. .
Thereby, the steam turbine 9 is rotated to drive the generator 10 to control the generated power. Further, the pressure control of the steam sent to the steam turbine 9 is performed by adjusting the opening degree of the pressure control valve 29 by the control device 39 based on the steam turbine inlet temperature detected by the pressure detector 6. That is, the pressure inside the steam separator 3 is controlled, and the surplus steam is sent to the exhaust heat treatment tank 32.

The level control of the waste heat heat water of the steam separator 3 is as follows.
The opening degree of the level control valve 30 is adjusted based on the control device 39 based on the exhaust hot water level detected by the level detector 4. Further, the level control of the exhaust heat heat water of the exhaust heat treatment tank 32 is performed by adjusting the opening degree of the level control valve 35 by the controller 39 based on the exhaust heat heat water level of the exhaust heat treatment tank 32 detected by the level detector 33. Is done.

On the other hand, the temperature of the exhaust heat of the exhaust heat treatment tank 32 is controlled by the temperature detector 38 at the outlet of the heat exchanger of the heat exchanger 28.
The control device 39 adjusts the opening degree of the temperature control valve 27 based on the temperature of the heat exchanger outlet detected by. The level control of the condenser 12 is based on the water level level of the condenser detected by the level detector 13
Is performed by adjusting the opening degree of the level control valve 16.

The level of the cooling tower 18 is controlled by adjusting the opening degree of the level control valve 23 by the controller 39 based on the transition level of the cooling tower detected by the level detector 20. The temperature of the tank of the cooling tower 18 is controlled by the controller 39 controlling the current supplied to the cooling tower fan 19 based on the tank temperature detected by the temperature detector 21 of the tank of the cooling tower 18.

Here, the control device 39 is constructed as shown in FIG. That is, the controller 39 controls the steam flow rate control system A, the steam pressure control system B, the hot water level control system C of the steam separator, and the water level control system D of the exhaust heat treatment tank.
A cooling water temperature control system E for the heat exchanger, a water level level control system F for the condenser, a water level level control system G for the cooling tower, and an internal temperature control system H for the cooling tower.

The steam flow rate control system A adjusts the flow rate control valve 8 at the steam turbine inlet so that the steam flow rate becomes a power setting value. That is, the detection signal of the flow rate detector 7 of the steam flowing through the exhaust heat steam flow path 5 is input, and the detected steam flow rate is made linear by the square root calculator 40. The steam flow rate is compared with the power set value 41 calculated as a function of the steam flow rate, and the deviation signal is calculated by the PID controller 42 to obtain a control signal. Then, the electropneumatic converter 43 converts the current signal into an air signal to control the opening degree of the flow rate control valve 8 at the inlet of the exhaust heat steam turbine. As a result, the steam flow rate is controlled by following the power set value of the generator 10.

Next, the steam pressure control system B adjusts the steam pressure at the steam turbine inlet by adjusting the outlet pressure adjusting valve 29 of the steam separator 3 so that the pressure of the steam separator 3 becomes the pressure set value. It regulates and controls. In this case, when the steam flow rate increases, the pressure of the steam separator 3 is controlled in advance so as not to decrease, and when the hot water level of the steam separator 3 increases, the pressure of the steam separator 3 is decreased. Control ahead in the direction that does not exist.

That is, the detection signal of the pressure detector 6 at the exhaust heat steam turbine inlet is input, the detected steam pressure is compared with the set value set in the steam turbine inlet pressure setter 45, and the deviation signal thereof is obtained. . On the other hand, the deviation signal obtained by comparing the deviation signal with the power setting device 41 is supplied to the bias device 4
4, the bias signal is obtained as a bias signal, and the deviation signal obtained by comparing the detection signal of the level detector 4 of the vapor separator 3 with the level setting device 49 of the vapor separator 3 is obtained as a bias signal. Signal is added. That is, the calculation signal obtained by inputting these signals to the addition / subtraction calculator 46 is P
It is obtained as a control signal by the ID controller 47. The control signal becomes a signal for controlling the opening degree of the pressure control valve 29 of the steam separator 3 by converting the current signal into an air signal by the electropneumatic converter 48. As a result, the excess steam is recovered in the exhaust heat treatment tank 32, and the inlet pressure of the exhaust heat steam turbine 9 is controlled by following the set value.

The hot water level control system C of the steam separator controls the hot water level of the steam separator 3 to the set value by adjusting the level adjusting valve 30. in this case,
The hot water level control system C of the steam separator controls in advance such that the hot water level of the steam separator 3 does not rise when the steam flow rate increases.

That is, the detection signal of the level detector 4 of the hot water level of the steam separator 3 is input, and the hot water level is compared with the set value set in the level setter 49 to obtain a deviation signal. Then, the deviation signal obtained by comparing with the power setting unit 41 is added to the deviation signal with the signal obtained as the bias signal by the bias unit 44. That is, the PID adjuster 52 obtains a calculation signal obtained by inputting these signals into the addition / subtraction calculator 51 as a control signal. The control signal becomes a signal for converting the current signal into an air signal by the electropneumatic converter 53 and controlling the opening degree of the level control valve 30 of the vapor separator 3. As a result, surplus hot water is recovered in the exhaust heat treatment tank 32, and the level of hot water in the steam separator 3 is controlled by following the set value.

The water level control system D of the waste heat treatment tank is
The level of the hot water in the exhaust heat treatment tank 32 is controlled by adjusting the level control valve 35 so as to reach the set value.
In this case, the water level control system D of the exhaust heat treatment tank is controlled in advance so that the hot water level of the exhaust heat treatment tank 32 does not increase when the hot water level of the steam separator 3 increases.

The control device 39 inputs the detection signal of the level detector 33 of the hot water level of the exhaust heat treatment tank 32 and compares the hot water level of the exhaust heat treatment tank 32 with the set value set in the level setter 55. And a deviation signal is obtained. To this deviation signal, the operation signal obtained by the addition / subtraction operation unit 51 is added to the bias unit 54.
The signal obtained as the bias signal is added. That is,
These signals are input to the addition / subtraction calculator 56, and the addition / subtraction calculator 5 is input.
The operation signal obtained in 6 is operated by the PID adjuster 52 to obtain a control signal. The control signal becomes a signal for controlling the opening of the level control valve 35 at the outlet of the exhaust heat treatment tank 32 by converting the current signal into an air signal by the electropneumatic converter 58, and thereby the level of the exhaust heat treatment tank 32 is changed. Control according to the set value.

The cooling water temperature control system E of the heat exchanger controls the outlet temperature of the heat exchanger 28 so as to be the set value by adjusting the temperature adjusting valve 27. In this case, when the hot water level of the exhaust heat treatment tank 32 increases, the cooling water temperature control system E of the heat exchanger controls the cooling water in an increasing direction in advance, and the cooling water temperature control system E of the exhaust heat treatment tank 32 also increases. When the internal temperature becomes high, the cooling water is controlled in advance so as to be increased.

That is, the exhaust heat of the exhaust heat treatment tank 32 is
The heat exchanger 28 exchanges heat with the cooling water supplied by the cooling water pump 26. The detection signal of the temperature detector 38 of the exhaust heat water of the heat exchanger 28 that has exchanged heat is input to the control device 39, converted into a current signal by the temperature converter 60, and converted into a temperature setting device 6.
The set value of 1 is compared. As the deviation signal, a signal obtained by the adder / subtractor 56 as a bias signal by the bias device 59 and a signal obtained by the adder / subtractor 66 are bias devices 67.
The signal obtained as a bias signal is added. Here, in the adder / subtractor 66, a signal obtained by converting the outlet exhaust hot water temperature of the heat exchanger 28 detected by the temperature detector 38 into a current signal by the temperature converter 60 and the temperature detection inside the exhaust heat treatment tank 32 are detected. The deviation signal from the signal obtained by converting the detection signal of the device 34 into the current signal by the temperature converter 65 is calculated.

That is, the heat exchanger 28 is included in the adder / subtractor 62.
A deviation signal between the outlet exhaust hot water temperature and its set value, a signal from the bias device 59, and a signal from the bias device 67 are input. Then, the operation signal obtained by the adder / subtractor 62 is operated as a control signal by the PID adjuster 64, and the electropneumatic converter 64 converts the current signal into an air signal to control the cooling water at the inlet of the heat exchanger 28. It becomes a signal for adjusting the opening degree of the temperature control valve 27. As a result, the exhaust heat temperature of the heat exchanger 28 is controlled by following the set value.

The water level control system F of the condenser controls the water level of the condenser to the set value by adjusting the level control valve 16. In this case, when the steam flow rate increases, the water level control system F of the condenser controls in advance the direction of decreasing the water level of the condenser. Further, when the outlet temperature of the heat exchanger 28 becomes high, the water level of the condenser is controlled so as not to decrease.

That is, the detection signal of the level detector 13 for detecting the condensate level of the condenser 12 is compared with the set value set in the level setter 69 of the condenser 12. The deviation signal is added with the signal obtained by the adder / subtractor 70 as the bias signal of the calculation signal of the addition / subtraction calculator 62 as the bias signal of the bias unit 68 and the signal obtained as the bias signal of the bias unit 44. The output signal from the adder / subtractor 70 is calculated as a control signal by the PID adjuster 71, and the electropneumatic converter 72 converts the current signal into an air signal to control the condensate level of the condenser 12 by following the set value. To do.

The water level control system G of the cooling tower is the cooling tower 1
The water level in the tank of No. 8 is controlled by adjusting the level control valve 23 so as to reach the set value. In this case, the water level control system G of the cooling tower controls in advance so that the water level in the tank of the cooling tower 18 does not rise when the water level of the condenser rises.

Level detector 2 in the tank unit of the cooling tower 18
The detection signal of 0 is compared with the set value set by the level setter 74 in the tank unit of the cooling tower 18. The deviation signal is added with the signal obtained by the adder / subtractor 75, which is the operation signal of the adder / subtractor 70, as the bias signal of the bias device 73. The output signal from the adder / subtractor 75 is calculated into a control signal by the PID controller 76, and the electropneumatic converter 77 converts the current signal into an air signal to control the opening of the level control valve 23 at the outlet of the makeup water pump 24. Signal. Thereby, the level in the tank unit of the cooling tower 18 is controlled by following the set value.

The internal temperature control system H of the cooling tower is the cooling tower 18
The temperature inside the tank of No. 2 is controlled to the set value by controlling the rotation speed of the cooling tower fan 19. In this case, the internal temperature control system H of the cooling tower controls in advance so that the temperature inside the tank does not rise when the water level of the condenser rises. Further, when the temperature of the cooling water that has undergone heat exchange is high, control is performed in advance so that the temperature in the tank unit of the cooling tower does not rise. Further, when the temperature inside the condenser is high, it is controlled in advance so that the temperature inside the tank unit of the cooling tower does not rise. In this case, either the temperature of the cooling water that has undergone heat exchange or the internal temperature of the condenser is selected to be the higher temperature, and the temperature inside the tank device of the cooling tower is controlled in advance so as not to rise.

Temperature detector 21 in the tank unit of the cooling tower 18
The detection signal of is converted into a current signal by the temperature converter 78,
It is compared with the set value of the temperature setter 79 in the tank of the cooling tower 18. The deviation signal and the bias signal of the bias unit 73 are input to the adder / subtractor 80.

On the other hand, a signal obtained by converting the detection signal of the temperature detector 21 inside the tank of the cooling tower 18 into a current signal by the temperature converter 78 and the detection signal of the inside temperature detector 14 of the condenser 12 are shown. The signal converted into the current signal by the temperature converter 86 is input to the adder / subtractor 85 to detect whether the temperature inside the condenser is high.

On the other hand, the detection signal of the temperature detector 21 in the tank of the cooling tower 18 is converted into a current signal by the temperature converter 78, and the signal is supplied by the cooling water pump 26 of the heat exchanger 28 to exchange heat. The detection signal detected by the cooling water temperature detector 37 and the signal converted into the current signal by the temperature converter 84 are input to the adder / subtractor 83 to detect whether or not the temperature in the tank unit of the cooling tower is high. To do.

Then, the signal from the adder / subtractor 85 and the signal from the adder / subtractor 83 are input to the high value priority circuit 87, a comparison operation is performed to take out the signal on the higher value side, and the biaser 88 adds it to the adder / subtractor 80 as a bias signal. The PID controller 81 obtains a control signal from the operation signal thus obtained, controls the current of the thyristor switch 82, and controls the rotation speed of the cooling tower fan 19. As a result, the temperature inside the tank of the cooling tower 18 is controlled following the set value.

Therefore, according to this embodiment, following the power load set value of the steam turbine generator using the exhaust heat,
Transient exhaust heat steam that compensates for fluctuations in the exhaust heat steam flow rate and steam pressure, level fluctuations in the steam separator, condenser, cooling tower, etc., and internal temperature fluctuations in the condenser, cooling tower, etc. Even with pressure fluctuations, surplus hot water can be used effectively and stable control can be achieved.

[0050]

As described above, according to the present invention, with respect to the electric power setting load of the exhaust heat utilization power plant, the steam turbine inlet of the steam turbine inlet due to the exhaust heat steam flow rate and the pressure fluctuation of the steam separator of the exhaust heat steam flow path is It is possible to prevent fluctuations in steam pressure, and further to prevent fluctuations in pressure and level inside the steam separator. Also,
To effectively use the surplus waste heat, the surplus waste heat water is stored in the waste heat treatment tank, and the temperature control signal from the waste heat treatment passage is added as a bias signal in advance in order to prevent the temperature fluctuation inside the condenser. As a result, the temperature inside the condensing device can be controlled stably.

Further, in order to prevent the temperature fluctuation in the cooling tower unit, the deviation signal between the level control signal of the condenser, the temperature inside the cooling tower, and the exhaust heat temperature that has exchanged heat with the cooling water and the condensate in advance. The deviation signal between the temperature inside the cooling tower and the temperature inside the cooling tower is obtained by the high value priority circuit and the high value side signal is obtained and added as a bias signal to stably control the inside temperature of the cooling tower, and the condenser It is possible to prevent fluctuations in the degree of vacuum. Therefore, stable control can be achieved by following the set power of the steam turbine generator, and stable control can be performed even for transient load fluctuations so that fluctuations in the steam turbine inlet pressure can be minimized as well as high efficiency. Can be operated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of an exhaust heat utilization power plant to which the present invention is applied.

[Explanation of symbols]

 A Steam flow rate control system B Steam pressure control system C Hot water level control system for steam separator D Water level control system for waste heat treatment tank E Cooling water temperature control system for heat exchanger F Water level control system for condenser G Cooling Tower water level control system H Cooling tower internal temperature control system 3 Steam separator 6 Pressure detector 7 Flow rate detector 9 Steam turbine 10 Generator 12 Condenser 18 Cooling tower 19 Cooling tower fan 28 Heat exchanger 32 Exhaust Heat treatment tank 39 Control device

Claims (6)

[Claims] 1. A control device for an exhaust heat utilization power plant, wherein a steam turbine is driven by exhaust heat steam to rotate a generator directly connected to the steam turbine to generate electric power, and the output of the generator is predetermined. Steam flow control system for controlling the flow rate of steam flowing into the steam turbine so that the electric power set value is set, and the hot water level of the steam separator for separating the exhaust heat steam into steam and hot water is a preset value. And a hot water level control system of the steam separator that controls in advance in a direction in which the hot water level of the steam separator does not rise when the flow rate of the steam flowing into the steam turbine increases, The internal pressure of the steam separator is controlled so that the steam pressure at the inlet of the steam turbine becomes a predetermined pressure set value, and the steam separator when the flow rate of steam flowing into the steam turbine increases. Steam pressure for controlling the internal pressure of the steam separator in the direction not to be reduced and for controlling the internal pressure of the steam separator to be not decreased when the hot water level of the steam separator is increased. A control device for an exhaust heat utilization power plant, comprising a control system. 2. The hot water level of the exhaust heat treatment tank for storing the exhaust heat steam and the exhaust heat hot water from the steam separator is controlled to a predetermined set value, and the hot water level of the steam separator is controlled. The exhaust heat utilization power plant according to claim 1, further comprising: a water level control system for the exhaust heat treatment tank, which controls the hot water level of the exhaust heat treatment tank in a direction in which the hot water level does not increase when the exhaust heat treatment tank increases. Control device. 3. The exhaust heat water outlet temperature in a heat exchanger for exchanging heat of waste heat water guided from the waste heat treatment tank to a condenser with cooling water from a cooling tower is controlled to be a preset value. In addition, when the hot water level of the exhaust heat treatment tank is increased, the cooling water is controlled in advance so as to be increased, and when the internal temperature of the exhaust heat treatment tank is high, the cooling water is increased. The control device for an exhaust heat utilization power plant according to claim 2, further comprising: a cooling water temperature control system for the heat exchanger that controls in advance in a direction to increase the temperature. 4. The water level of the condenser is controlled to a predetermined set value, and when the flow rate of the steam introduced to the steam turbine is increased, the water level of the condenser is decreased. A water level control system for a condenser, which is controlled in advance and is controlled in a direction in which the water level is not reduced when the exhaust heat water outlet temperature in the heat exchanger rises, is provided. The control device of the waste heat utilization power plant according to claim 3. 5. The condensate from the condenser is guided, and the water level in the tank unit of the cooling tower for circulating the cooling water to the heat exchanger is controlled to a predetermined set value. In addition, when the water level of the condenser rises, a water level control system of the cooling tower is provided so as to control in advance so that the water level in the tank of the cooling tower does not rise. The control device of the waste heat utilization power plant according to claim 4. 6. The temperature in the tank unit of the cooling tower is controlled so as to reach a predetermined set value, and when the water level of the condenser rises, the temperature in the tank unit of the cooling tower is controlled. When the temperature of the cooling water from the heat exchanger and the temperature inside the condenser are high, the temperature of the cooling water from the heat exchanger is controlled so that it does not rise. The control device for an exhaust heat utilization power plant according to claim 5, further comprising an in-container temperature control system of the cooling tower, which is controlled in advance so that the temperature does not rise.