JPH0518212A - Waste heat utilizing power generation control device - Google Patents

Abstract

PURPOSE:To obtain stabilized output of a power generator at all times regardless of any change in a hot water flow amount or a hot water temperature. CONSTITUTION:Hot water discharged from a hot water pump 1 flows on the primary side of preheaters 8 to 12 after passing a hot water system. A medium system 15 passes on the second any side of the preheaters 8 to 12, and a medium heated by heat by heat exchange with hot water is supplied to a medium turbine 21 so as to rotate the medium turbine 21. After that, the medium is condensated through condensers 25, 27, and circulated to a medium pump 39 through a medium tank. Cooling water in a cooling system passes through the condensers 25, 27. The opening degree of each of adjusting valves 5, 6, 19, 3, 38, 40, 41 is controlled by an adjusting valve controller 42 on the basis of detection of a flow amount, a temperature, and pressure in each system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation control device utilizing exhaust heat obtained from hot water of industrial plants or underground hot water.

[0002]

2. Description of the Related Art Power generation methods include thermal power generation, hydroelectric power generation,
In addition to the nuclear power generation system, there are various special 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.

This type of power generation system, like thermal power generation, attempts to rotate the turbine with steam, but the fuel cost required to rotate the turbine can be greatly reduced compared to thermal power generation. Recently, attention has been paid to the utilization of resources.

[0004]

By the way, in the conventional exhaust heat utilization power generation control device, no special control is performed on the flow rate of the hot water, and all of the exhaust heat obtained from the industrial plant is driven by the turbine. It is used and basically the maximum power operation is performed.

However, in such power generation control, when the flow rate of hot water or the temperature of hot water from an industrial plant or the like changes, the output of the generator also fluctuates immediately, and there is a drawback that the control is left to completion.

The present invention has been made in view of the above circumstances, and exhaust heat that can always obtain a stable generator output regardless of changes in the hot water flow rate or the hot water temperature from an industrial plant or the like. It is intended to provide a utilization power generation control device.

[0007]

As a means for solving the above-mentioned problems, the present invention is provided in the middle of a medium circulation channel,
A medium turbine that drives a generator by the rotational force obtained by a heating medium, and a medium that is provided on the upstream side of the medium turbine in the medium circulation flow path and that uses hot water sent from a hot water source through a hot water supply path. A preheater that performs preheating, a condenser that is provided on the medium turbine downstream side of the medium circulation flow path, and that condenses the medium by the cooling water that circulates in the cooling water circulation flow path, and the hot water supply path A hot water flow rate control valve provided on the upstream side of a preheater, a medium circulation amount control valve provided on the preheater upstream side of the medium circulation flow path and a bypass path of the medium turbine, and the cooling water circulation flow path. And a control of each of the control valves based on the flow rate detection, temperature detection, and pressure detection at predetermined locations of the hot water supply passage, the medium circulation passage, and the cooling water circulation passage provided in the With the control valve controller It is obtained by a configuration with a.

[0008]

In the above structure, the hot water from the hot water source is sent to the preheater via the hot water supply passage. Heat exchange is performed in the preheater, and the medium in the medium circulation flow path is heated and sent to the medium turbine.

After passing through the medium turbine, the medium exchanges heat with the cooling water passing through the cooling water circulation passage in the condenser and is condensed there.

The flow rate, temperature, and pressure at predetermined locations of the hot water supply passage, the medium circulation passage, and the cooling water circulation passage are detected, and the detection signals are sent to the control valve controller. The controlled flight controller controls the opening degree of the control valve provided in each flow path based on the detection signal.

That is, the turbine is not directly driven by the hot water from the hot water source, but is indirectly driven by the interposition of the medium. The control valve controller controls the flow rate of the control valve of each flow path so that the rotation speed of the medium turbine is always at a constant level when the flow rate detection signal and the temperature detection signal from the hot water supply path change. Take control.

[0012]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a system diagram showing the overall configuration of an embodiment of the present invention. In this figure, hot water flows from the underground hot water tank to the hot water system 4 by the hot water pump 1, and is sent to the preheater (A) 8 and the preheater (B) 9. The adjustment of the hot water flow rate is controlled by the opening degree of the flow rate control valve 5 that adjusts the hot water flow rate, and the flow rate is detected by the hot water flow rate detector 2. The hot water flow rates of the preheater (C) 11 and the preheater (D) 12 are controlled by the opening degree of the hot water flow rate control valve 6.

The inlet temperature of the hot water of the preheater (A) 8 and the preheater (C) 11 is detected by the hot water temperature detector 3, and the outlet temperature of the preheater (B) 9 and the preheater (D) 12 is It is detected by the temperature detectors 10 and 13. Preheater 8, 9, 11, 1
The hot water that has finished heat exchange in 2 is returned to the underground.

The medium on the secondary side of the preheater 9 and the preheater 12 is supplied by a medium pump 39, and the flow rate thereof is controlled by the openings of the heat medium control valves 41, 40. The preheater 9 and the preheater 12 exchange heat with the medium in the preheater 9 and the preheater 12 so that the detection value of the temperature detector 14 provided at the inlet of the medium turbine 21 becomes a specified value. The flow rate of the heat medium is controlled by the heat medium control valves 41 and 40. Then, the medium flowing into the medium system 15 rotates the medium turbine 21 and drives the generator 22 to generate electricity.

At this time, the inlet pressure of the medium turbine 21 flowing through the medium system 15 is the inlet pressure detector 18 of the medium turbine.
The adjustment valve 19 provided in the medium turbine bypass passage 20 controls so that the detection signal of 1 becomes a specified value.

Exhaust heat spent for driving the medium turbine 21 is supplied to the condensers 25 and 27, and the cooling water supply pump 35
Thus, the heat is exchanged with the supplied cooling water, and then the medium is stored in the medium tank 28. Regarding the cooling temperature of the medium in the medium tank 28, the openings of the control valves 33 and 38 are controlled so that the detection signal of the temperature detector 30 becomes a specified value. And condenser 2
The temperature of the cooling water on the secondary side, which has undergone heat exchange with the mediums 5, 27, flows to the cooling tower 34, is cooled by the cooling tower fan, and is circulated.

The controller 42 controls the temperature detection signals 3, 10,
13, 14, 17, 24, 26, 30, 31, 32, 3
6, the flow rate detection signal 2 and the pressure detector signal 18 are input, and the flow rate control valves 5, 6, 19, 33, 38, 40, 41 are input.
A control signal is output to control the valve opening and control the flow rate.

The functional details of the apparatus of FIG. 1 constructed as described above are as follows. First, consider the control signal of the control valve 5 that controls the flow rate of hot water and the power set value of the generator 22.

When the deviation of the control signal of the regulating valve 5 is equal to or larger than the specified value, the hot water system 4 is controlled in accordance with the electric power load so as to increase the heat exchange amount of the preheaters 8 to 12, and the hot water system 4 is also controlled. The temperature detector 14 at the inlet of the medium turbine generator 22 and the temperature detector 17 at the outlet of the medium pump 39 against the increase in the power load of
The deviation signal is added as a bias signal in advance to increase the flow rate of hot water, thereby controlling the opening degree of the flow rate control valve 5. Also, when the control deviation from the power setting is large,
The hot water flow rate is increased by following the flow rate control valve 5 in advance to control the opening degree of the flow rate control valve 40 at the inlets of the preheaters 11 and 12 to follow the power load fluctuation.

On the other hand, the medium flow rate to the medium turbine 21 is also increased as the flow rate of the hot water system 4 increases.
The deviation of the signal of the hot water temperature detector 3 and the signal of the temperature detector 2 is added in advance as a bias signal to the medium flow rate for heat exchange in 9 to control the opening degree of the medium flow rate control valve 41. It controls by following the temperature change of hot water.

When the electric power load transiently increases, the deviation signal between the signal of the temperature detector 3 and the signal of the temperature detector 13 is controlled similarly to the opening control of the flow rate control valve 5 at the inlet of the preheater 8. Is added in advance as a bias signal to make the temperature setting signal at the inlet of the medium turbine 21 follow, and the flow control valve 4
The opening degree of 0 is controlled. Accordingly, the preheater 8 to follow the load so that the temperature at the inlet of the medium turbine 21 becomes constant.
12 medium flow rates are controlled.

Further, the preheaters 18 to 1 for the set power value
The medium flow rate of the medium turbine 21 increases with the changes in the hot water flow rate and the medium flow rate of 2, and the exhaust amount of the medium turbine 21 also increases accordingly. Therefore, as for the amount of cooling water in the cooling system, a bias signal is used as a deviation signal between the signal from the temperature detector 24 that detects the medium temperature at the inlet of the condenser 25 and the signal from the temperature detector 30 that detects the temperature of the medium tank 28. Is added to the control signal of the medium tank temperature to control the opening degree of the flow rate control valve 33 of the condenser 25 so that the temperature of the medium tank 28 reaches a specified value.

Further, the deviation signal between the signal of the temperature detector 24 for detecting the exhaust temperature of the medium turbine 21, that is, the temperature of the inlet of the condenser 27 and the signal of the temperature detector 30 for detecting the temperature of the medium tank 28 is set in advance. As a bias signal to control the opening degree of the flow control valve 38 of the condenser 27. In this way, the temperature change amount with respect to the flow rate fluctuations of the hot water system 4 and the medium system 15 accompanying the power load fluctuation is added in advance as bias signals so that the temperature of the medium tank 28 becomes a specified value. , Flow control valves 5, 6, 41, 40, 3
The opening degree of 3, 38 is controlled.

Then, with respect to the control signal based on the pressure detection of the pressure detector 18 provided at the inlet of the medium turbine 21,
Temperature detector 17 for detecting the temperature of the inlets of the preheaters 9 and 12
Deviation signal from the signal from the temperature detector 14 that detects the temperature of the inlet of the medium turbine 21 is added in advance as a bias signal so that the pressure at the inlet of the medium turbine 21 reaches a specified value. Control the opening.

By such control, it is possible to obtain a good followability even against the disturbance of hot water, the medium, the cooling water, and the transient fluctuation of the electric power load. As described above, the turbine 2 is constructed by using the two systems of the hot water system 4 and the medium system 15.
The control method for driving 1 may be referred to as a binary cycle power generation control method.

Next, the operation of FIG. 1 will be schematically described. First, when the electric power load is set, the hot water flow rate of the hot water system 4 is controlled so that the medium temperature of the medium turbine 21 becomes a set value. That is, the opening degree of the flow rate control valve 5 is controlled by a function of power load setting so that the preheaters 8 and 9 can obtain the amount of hot water required for heat exchange. Next, the valve opening is controlled by the flow rate control valve 41 so that the temperature at the inlet of the medium turbine 21 becomes a specified value so that the medium flow rate required for heat exchange can be obtained in the preheaters 8 and 9.

Then, the opening of the pressure control valve 19 is controlled so that the medium pressure of the medium turbine 21 becomes a specified value. The exhaust heat spent for driving the medium turbine generator 22 is heat-exchanged with the cooling water in the condenser 25, and the opening degree of the flow control valve 6 for adjusting the cooling water amount is adjusted so that the temperature of the medium tank 28 becomes a specified value. Controlled.

When the power load setting is increased, or when the hot water temperature fluctuates transiently, the preheaters 8 and 9 are used.
The amount of evaporation of the medium transiently increases with an increase in the amount of hot water. Therefore, the opening degree of the hot water flow rate control valve 6 is controlled so that the hot water amounts are supplied to the preheaters 11 and 12 by the control deviation.

At this time, the second-order lag of the heat exchange amount due to the fluctuation of the hot water and the increase of the flow rate of the medium is compensated so that the inlet temperature of the medium turbine 21 becomes a specified value. That is,
The variation between the inlet temperature of the medium turbine 21 and the inlet temperatures of the preheaters 8 to 12 is added in advance to the hot water flow rate control valves 5 and 6 as a bias signal to control the opening thereof. As a result, the output of the generator 22 of the medium turbine 21 is controlled to be stable with respect to the set value.

Since the exhaust heat spent for driving the medium turbine 21 increases and decreases as the load of the medium turbine generator 22 changes, the temperature of the medium tank 28 also changes. Therefore, a secondary delay occurs with respect to heat exchange between the exhaust heat of the condenser 25 and the amount of cooling water. Therefore, in response to the opening signal of the flow rate control valve 33 that adjusts the amount of cooling water of the condenser 25, the condenser 25,
The deviation between the signal of the temperature detector 24 for detecting the inlet temperature of 27 and the signal of the temperature detector 30 for detecting the temperature of the medium tank 28 is added in advance as a bias signal.

As a result, the exhaust heat medium temperature of the condensers 25 and 27 is controlled so as to follow the amount of the exhaust heat medium from the turbine 21 so as to reach the specified value. And the condensers 25, 2
The cooling water that has exchanged heat with the medium of No. 7 is sent to the cooling tower 34 and cooled by the cooling tower fan.

In this case, the cooling temperature fluctuates as the amount of heat exchange with the medium of the condensers 25 and 27 fluctuates, so the temperature detector 3 for detecting the cooling water temperature at the outlets of the condensers 25 and 27.
The deviation between the signal of 1, 32 and the signal of the temperature detector 36 for detecting the temperature of the cooling water cooled by the cooling tower fan is added to the control valves 33, 38 as a bias signal in advance, and the temperature of the medium tank 28 is It is controlled to reach the specified value.

Next, the structure of the control valve controller 42 will be described with reference to FIG. In this figure, first, the hot water flow rate detector 2
The detection signal of is converted into a linear signal by the square root calculator 43, and the set value is compared by the power setter 44. Then, the deviation signal becomes a control signal in the PID controller 45, and the addition / subtraction calculator 46
Sent to.

On the other hand, the deviation between the signal obtained by converting the signal of the temperature detector 14 into the current signal by the temperature converter 52 and the signal obtained by converting the signal of the temperature detector 17 into the current signal by the temperature converter 65 is adjusted. 66, and further the bias device 67
Biased at. Then, after adding this bias signal to the control signal calculated by the adder / subtractor calculator 46, the bias signal is converted into an air signal by the electropneumatic converter 47, and the hot water flow rate of the preheater 8 is adjusted to the power set value. The opening of the valve 5 is controlled.

Further, the deviation signal of the power setting unit 44 is checked by the limiter 48, and if it is equal to or more than the limit value, the PID controller 4
The control signal obtained in 9 is sent to the addition / subtraction calculator 50. At this time, the bias 67 signal from the bias unit is also added / subtracted by the addition / subtraction calculator
Sent to. Then, the control signal is converted into an air signal by the electropneumatic converter 51 and sent to the flow rate control valve 6.

Inlet medium temperature detector 1 of medium turbine 21
The detection signal of 4 is converted into a current signal by the temperature converter 52,
The deviation from the set value calculated by the medium turbine inlet temperature setting device 53 becomes a control signal in the PID controller 54, and is sent to the addition / subtraction calculator 55.

On the other hand, the detection signal of the hot water temperature detector 3 at the outlet of the hot water pump 1 is converted into a current signal by the temperature converter 62, and the detection signal of the outlet hot water temperature detector 10 of the preheater 9 is detected. The signal converted into the current signal by the temperature converter 57 is input to the addition / subtraction arithmetic unit 63, and the signal obtained by biasing the arithmetic signal by the bias unit 64 is also sent to the addition / subtraction arithmetic unit 55. Then, the calculated signal is converted into an air signal by the electropneumatic converter 56 and becomes a control signal of the medium flow rate control valve 41 to control the opening so that the medium turbine inlet temperature becomes a set value.

When the control deviation signal from the medium temperature setter 53 exceeds the limit value of the limiter 58, the deviation signal is
It becomes a control signal in the PID controller 59 and is sent to the addition / subtraction calculator 60.

At this time, the current signal from the temperature converter 62 and the signal obtained by converting the detection signal of the temperature detector 13 into the current signal by the temperature converter 70 are sent to the addition / subtraction calculator 71, and the deviation signal thereof is biased. The signal biased by the device 72 is also added to the addition / subtraction calculator 60. Then, the operation signal becomes a control signal and is converted into an air signal by the electropneumatic converter 61,
The opening degree of the inlet heat medium flow rate control valve 40 of the preheater 12 is controlled. Therefore, the inlet temperature of the medium turbine 21 is controlled to reach the set value.

The detection signal of the temperature detector 30 is converted into the temperature converter 7
The deviation signal obtained after being converted into a current signal in 3 and compared with the set value in the temperature setter 74 becomes a control signal in the PID controller 75, and is input to the addition / subtraction calculator 76.

At this time, the signal obtained by biasing the signal from the addition / subtraction arithmetic unit 46 by the bias unit 68 is also input to the addition / subtraction arithmetic unit 76. Further, a signal obtained by converting the detection signal of the temperature detector 31 into a current signal by the temperature converter 84 and a signal obtained by converting the detection signal of the temperature detector 36 into a current signal by the temperature converter 86 are input to the addition / subtraction calculator 85. To be done. The signal obtained by biasing the deviation signal by the bias device 87 is also added / subtracted by the addition / subtraction calculator
Entered in. Further, the signal from the temperature converter 73 is sent to the addition / subtraction calculator 78, which includes the temperature detector 2
A signal obtained by converting the detection signal of No. 4 by the temperature converter 79 is also sent. The signal from the temperature converter 78 is also input to the addition / subtraction calculator 76.

The calculation signal of the addition / subtraction calculator 76 is the electropneumatic converter 7.
At 7, the air signal is converted into a control signal, and the opening degree of the control valve 33 is controlled so that the temperature in the medium tank 28 becomes a set value.

The deviation signal from the temperature setter 74 is the limiter 8
If it is checked at 0 and exceeds the limit value, the deviation signal becomes a control signal at the PID controller 81 and is input to the addition / subtraction calculator 82. At this time, the signal obtained by biasing the signal from the addition / subtraction calculator 50 by the bias device 69 and the signal from the addition / subtraction calculator 78 are also input to the addition / subtraction calculator 82. further,
The signal from the addition / subtraction calculator 85 is sent to the addition / subtraction calculator 89, and the signal obtained by converting the detection signal of the temperature detector 32 by the temperature converter 88 is also sent to this. A signal obtained by biasing the signal from the adder / subtractor 89 with the bias device 90 is also input to the adder / subtractor 82.

The calculation signal of the addition / subtraction calculator 82 is an electropneumatic converter 8.
At 3, the air signal is converted into a control signal, and the opening degree of the cooling water amount control valve 38 of the condenser 27 is controlled so that the internal temperature of the medium tank 28 reaches a set value.

The deviation signal obtained by comparing the detection signal of the pressure detector 18 with the set value by the medium turbine inlet pressure setting device 91 becomes a control signal by the PID controller 92 and is input to the adjusting calculator 93. At this time, the bias signal from the bias device 67 is also input to the addition / subtraction calculator 93.

The calculation signal of the addition / subtraction calculator 93 is an electropneumatic converter 9.
In step 4, the air signal is converted into a control signal, and the opening degree of the bypass pressure control valve 19 is controlled so that the inlet pressure of the medium turbine 21 becomes a set value.

Therefore, according to the present embodiment, it is possible to control the plurality of preheaters and the plurality of condensers in accordance with the power load of the medium turbine, and to control the preheater and the preheater.
It is possible to prevent a secondary delay due to heat exchange of the condenser and prevent a decrease in heat exchange efficiency.

[0048]

As described above, according to the present invention, the turbine is not driven directly by the hot water from the hot water source, but indirectly by interposing a medium, and Based on the flow rate detection, temperature detection and pressure detection at a predetermined location in the hot water supply passage, the medium circulation passage, and the cooling water circulation passage, the control valve of the control valve of each passage is controlled. Even if the hot water flow rate or the hot water temperature changes, the generator output can be controlled to be stable.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration of a control valve controller in FIG.

[Explanation of symbols]

 15 medium circulation flow path (medium system) 16 medium circulation flow path (medium system) 21 medium turbine 22 generator 1 hot water source (hot water pump) 4 hot water supply path (hot water system) 8 to 12 preheater 25 condenser 27 Condenser 5 Hot water flow rate control valve 6 Hot water flow rate control valve 20 Medium circulation rate control valve 40 Medium circulation rate control valve 41 Medium circulation rate control valve 33 Cooling water rate control valve 38 Cooling water rate control valve 42 Control valve controller

Claims (1)

Claim: What is claimed is: 1. A medium turbine which is provided in the middle of the medium circulation passage and drives a generator by a rotational force obtained by a heating medium, and a medium turbine upstream side of the medium circulation passage. And a preheater that preheats the medium with the hot water sent from the hot water source through the hot water supply passage, and is provided on the medium turbine downstream side of the medium circulation passage and circulates through the cooling water circulation passage. A condenser for condensing the medium with cooling water, a hot water flow rate adjusting valve provided on the preheater upstream side of the hot water supply passage, the preheater upstream side of the medium circulation flow path, and the medium. A medium circulation amount control valve provided in a bypass passage of a turbine, a cooling water amount control valve provided in the cooling water circulation passage, and a predetermined location of the hot water supply passage, the medium circulation passage, and the cooling water circulation passage. Flow rate detection, temperature detection And a control valve controller that controls each of the control valves based on pressure detection, and an exhaust heat utilization power generation control device.