JPH08200094A - Turbine bearing oil temperature control device - Google Patents

Abstract

PURPOSE: To easily prevent an excessive flow rate of water in a bearing oil area regardless of a preset value of a parameter of PID control by adding a bearing oil cooling water excessive flow rate preventive circuit, and controlling opening of a bearing oil temperature adjusting valve by output of a low value preferential circuit. CONSTITUTION: In a bearing cooling water excessive flow rate preventive circuit 40, in a condition where an optimal temperature preset value of bearing oil is not more than 43 deg.C or rotating speed of a turbine 10 is not more than 3500rpm, opening restriction is outputted from a low value preferential circuit 44 so that opening of a bearing oil temperature adjusting valve 21 does not become 50% or more. As a result, excessive cooling of bearing oil caused by an excessive flow rate of bearing oil cooling water in a transitional change in starting, stopping or the like of the turbine 10 can be reliably prevented. Since the opening restriction of the bearing oil temperature adjusting valve 21 is imposed, an undershooting condition of a bearing oil temperature by excessive cooling of bearing oil can be prevented at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine bearing which is supplied to a bearing of a steam turbine, a gas turbine or the like installed in a thermal power plant / nuclear power plant or a combined cycle power plant, and lubricates and cools this bearing. The present invention relates to an improvement in an oil temperature control device, and more particularly to a turbine bearing oil temperature control device provided with a bearing oil cooling water overflow prevention circuit for preventing the bearing oil cooling water flow amount of the turbine bearing oil temperature control device from becoming excessive.

[0002]

2. Description of the Related Art A steam turbine, a gas turbine, or the like (hereinafter referred to as a turbine) used for power generation is one of the largest large-scale machines in its capacity, and therefore prevents thermal deformation of the rotor even when the operation is stopped. In order to achieve this, turning is performed at a very low speed of several revolutions per minute, and the speed is gradually increased from start to operation over several hours, and at the time of operation, it is rotated at a high speed of several thousand revolutions per minute. It is a horizontal axis rotating machine.

For the above reasons, the temperature of the turbine bearing oil which is supplied to the bearing to lubricate the bearing and to cool the bearing at the same time is adjusted so that the viscosity of the bearing oil, which changes depending on the temperature, has an optimum value.
It is necessary to strictly control to an appropriate value determined according to the rotation speed of the turbine.

Although not shown, in the conventional turbine bearing oil temperature control device, a circuit for preventing an excessive flow rate of the bearing oil cooling water sent to the bearing oil cooler is not provided, and the temperature control is performed. The control gain of the controller is slowed down only by PID control [3 operation control of (P) proportional operation + (I) integral operation + (D) derivative operation] to control the bearing oil cooling water supply flow rate. The opening of the bearing oil temperature control valve was prevented from becoming too large to prevent the bearing oil cooling water flow rate from becoming too large.

[0005]

However, the PID
It is not possible to completely prevent the bearing oil cooling water flow rate from becoming excessive by controlling only, and it also occurs during normal operation of the turbine, but especially during trial operation, the bearing oil cooling water flow rate often becomes too high, As the suction pressure of the regular bearing oil cooling water pumps installed in two units decreases,
The backup emergency bearing oil cooling water pump is activated, which further increases the bearing oil cooling water flow rate, overcools the bearing oil, and causes the bearing oil temperature to drop abnormally.

As described above, the conventional turbine bearing oil temperature control device does not have a circuit for preventing an excessive flow rate of the bearing oil cooling water, and the bearing is tuned by tuning for improving the response during transient response of PID control. An overflow of oil cooling water was occurring.

The present invention has been made in view of the above circumstances, and an object thereof is to add a circuit for preventing an excessive flow rate of bearing oil cooling water and to cool the bearing oil regardless of the set values of the PID control parameters. An object of the present invention is to provide a turbine bearing oil temperature control device capable of preventing an excessive flow rate of water.

[0008]

In order to achieve the above object, the present invention provides a bearing in which the flow rate of turbine bearing oil supplied to the bearing of a turbine is adjusted by controlling the opening of a bearing oil temperature control valve. A turbine bearing oil cooler that cools with oil cooling water, a bearing oil temperature detector that detects the temperature of the turbine bearing oil and outputs the bearing oil temperature, and a rotation speed of the turbine that outputs the rotation speed. A rotation speed detector, a function converter for inputting the rotation speed and outputting an optimum temperature set value of the turbine bearing oil according to the rotation speed of the turbine, and inputting the bearing oil temperature and the optimum temperature set value The temperature deviation signal is input to the comparator that outputs the temperature deviation signal of both inputs, and the temperature deviation signal is subjected to calculations such as proportional, integral, and differential, and the operation signal of the bearing oil temperature control valve is output. PID calculator, a first opening setting device for setting a predetermined maximum opening limit value of the bearing oil temperature control valve, and a fully open opening value of the bearing oil temperature control valve are set. The second opening degree setter, the maximum opening degree limit value of the first opening degree setter, and the full opening degree value of the second opening degree setter are input, and the optimum output of the function converter is output. When at least one of the temperature set value and the rotational speed of the turbine is smaller than a predetermined value, the previous maximum opening limit value is output, and the optimum temperature set value output by the function converter or the rotational speed of the turbine is output. Of at least one of the two, which is switched when it becomes larger than a predetermined value, and which outputs the operation value and the output of the switching device, which is switched to output the full-open opening value in the previous period, Pass through the input with one value Characterized by comprising a low value preference circuit that outputs to the bearing oil temperature control valve, the.

[0009]

By adding an overflow prevention circuit for the bearing oil cooling water, the set temperature of the turbine bearing oil temperature during turbine turning and the turbine bearing oil temperature is, for example, 40 to 45 ° C., and the rotational speed of the turbine is approximately 95% of the rated rotational speed. % Of 3500 rpm or less, the maximum opening of the bearing oil temperature control valve is, for example, 50%.
Therefore, at other times, the above-mentioned opening degree restriction is canceled. Therefore, it is possible to prevent the overflow of the bearing oil cooling water regardless of the set values of the PID control parameters.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram showing an embodiment of a turbine bearing oil temperature control device of the present invention.

In FIG. 1, 10 is a turbine, 10a is a bearing of the turbine 10, and 11 is a rotation speed detector for detecting and outputting the rotation speed of the turbine 10.

Reference numeral 13 is a bearing oil cooler for cooling the bearing oil that is pumped from a turbine bearing oil tank (not shown) by the bearing oil pump 15 and is supplied to the bearing 10a of the turbine 10 through the oil supply pipe 16. Reference numeral 17 is a bearing oil temperature detector that detects and outputs the temperature of the bearing oil supply.

A bearing oil cooling water 19, which is controlled by a bearing oil cooling water temperature control device (not shown) and adjusted to a predetermined constant temperature, is sent to the bearing oil cooler 13 via a bearing oil cooling water pipe 20. It is a bearing oil cooling water pump, and 21 is
This is a bearing oil temperature control valve that is provided in the bearing oil cooling water pipe 20 and has its opening controlled by a turbine bearing oil temperature control device described later to adjust the flow rate of the bearing oil cooling water.

Reference numeral 25 is a first function converter, to which the rotational speed of the turbine 10 detected by the rotational speed detector 11 is input, and the optimum temperature signal (optimal temperature of the bearing oil corresponding to the input turbine rotational speed (optimal Output temperature setting value).

Reference numeral 26 is a comparator, which receives the optimum temperature set value as the output of the first function converter 25 and the bearing oil temperature obtained from the bearing oil temperature detector 17 and both inputs. The temperature deviation signal of the temperature is output.

A temperature deviation signal, which is the output of the above-mentioned comparator 26, is given as an input to 27, and an operation such as proportional (P), integral (I), derivative (D) is applied to this temperature deviation signal. The PID calculator outputs the operation signal of the bearing oil temperature control valve 21.

A portion surrounded by an alternate long and short dash line and having a reference numeral 30 is a bearing oil temperature overshoot preventing circuit for preventing the temperature of the turbine bearing oil from being excessively increased, which is not directly related to the present invention. .

The overshoot prevention circuit 30 switches the second function converter 31, the fixed terminals a and b, and the fixed terminals a and b to connect the fixed contact c to the fixed contact c. And a minimum opening setting device 33 for setting the minimum opening limit value of the bearing oil temperature control valve 21, and two inputs having different values are given. And a high-value priority circuit 34 that passes the input having the higher value among them and outputs it.

The second function converter 31 receives the bearing oil temperature detected by the bearing oil temperature detector 17, and outputs an optimum opening signal of the bearing oil temperature control valve 21 corresponding to the input bearing oil temperature. To do.

The fixed terminal a of the first switch 32 receives the set value output of the minimum opening setter 33 for setting the minimum opening limit value of the bearing oil temperature control valve 21, for example, 0%. The output of the second function converter 31 is input to the fixed terminal b. The optimum temperature setting value of bearing oil is, for example, 46 degrees C.
And when the temperature of the bearing oil is, for example, 43 ° C or higher,
The switching contact T is connected between the fixed terminals b and c as shown in the figure, and during normal operation of the turbine other than the above, the switching contact T is automatically switched to the fixed terminal a side and the fixed terminal a.
-C is connected.

The high price priority circuit 34 has one input as the output of the first switch 32 and the other input as the PI.
The operation signal output from the D calculator 27 is input, and the input having the higher value is passed and output.

A portion surrounded by an alternate long and short dash line and having a reference numeral 40 is a bearing oil cooling water overflow prevention circuit for cooling the bearing oil added according to the present invention. The bearing oil temperature control valve 2
The first opening degree setter 41 in which the maximum opening degree limit value of 1 is set
Of the bearing oil temperature control valve 21 and a second switching device 42 having a fixed contact a and b and a switching contactor T for switching between the fixed terminals a and b to connect the fixed terminal c. A second opening setter 43 for setting a fully open opening value and a low value that is supplied with two inputs having different values and passes an input having a lower value of the two inputs and outputs the same. And a priority circuit 44.

The second switching device 42 has a fixed terminal a at which the fully open opening value 100% set by the second opening setting device 43 is set.
Of the set value of the first opening degree setting device 41 to the fixed terminal b.
The set value output of, for example, 50% of the maximum opening limit value set in is input, and the optimum temperature set value of the bearing oil is, for example, 43 ° C. or less, or the rotational speed of the turbine is, for example, 3
At 500 rpm or less, the switching contact T connects between the fixed terminals b and c as shown in the figure, and during normal operation of the turbine other than the above, the switching contact T is automatically switched to the fixed terminal a side and fixed. Connect between terminals a and c.

The low value priority circuit 44 is supplied with the output of the high value priority circuit 34 as one input and the output of the second switch 42 described above as the other input, and the lower one It passes an input that has a value and outputs it.

As described above, since the overshoot prevention circuit 30 is not directly related to the present invention, this circuit 30
Is not used, the high price priority circuit 34 is excluded,
The low value priority circuit 44 receives the above-mentioned P as one of its inputs.
It goes without saying that the operation signal output from the ID calculator 27 is given.

Next, the operation of the present invention having the above-mentioned structure will be described in detail with reference to FIGS. 1 to 3. In the present invention, the following two items are preconditions.

That is, (1) turbine bearing oil which is pumped from a turbine bearing oil tank (not shown) by the bearing oil pump 15, cooled by the bearing oil cooler 13 and supplied to the bearing 10a of the turbine 10 through the oil supply pipe 16. The flow rate of is kept at a predetermined constant value.

(2) A bearing for cooling the bearing oil, which is discharged from the bearing oil cooling water pump 19, whose flow rate is adjusted according to the opening degree of the bearing oil temperature control valve 21 and is sent to the bearing oil cooler 13 described above. The temperature of the oil cooling water is adjusted by a bearing oil cooling water temperature control device not related to the present invention, and is maintained at a predetermined constant value.

2 and 3 are curve diagrams for explaining the operation of the present invention.

In FIG. 2, the horizontal axis represents time, and the vertical axis represents bearing oil temperature (degree C). The solid line curve a is the bearing oil temperature curve, and the dashed line curve b is the bearing oil temperature. 2 is an optimum temperature set value curve of.

In FIG. 3, the horizontal axis represents time, the vertical axis represents the opening (%) of the bearing oil temperature control valve 21, and the curve c is the bearing oil temperature control valve 21 by the bearing oil cooling water overflow prevention circuit 40. Is a maximum opening limit curve for the bearing oil temperature control valve 21 by the bearing oil temperature overshoot prevention circuit 30.
It is a minimum opening degree restriction curve for.

During the turning of the turbine 10 before starting, the turbine 10 is rotating at a low speed of several revolutions per minute. At this time, for example, a minimum opening limit value 0% is set in the minimum opening setter 33 that sets the minimum opening limit value of the bearing oil temperature control valve 21 as shown in the figure, and the first opening setting value is set. For example, a maximum opening limit value of 50% is set in the device 41, and a fully open opening value of 100% is set in the second opening setting device 43.

The optimum temperature set value of the turbine bearing oil output from the first function converter 25 is, as shown in the figure, for example, 30 degrees C and 800 rpm when the input rotation speed of the turbine 10 is less than 800 rpm. At a rated turbine rotation speed of 3600 rpm, the temperature is almost proportional to the rotation speed, and at 3600 rpm or higher, the temperature is 46 ° C.
Further, the optimum opening signal of the bearing oil temperature control valve 21 output from the second function converter 31 is, for example,
When the temperature of the input turbine bearing oil is less than 43 ° C, it is 0%, at 43 to 46 ° C, the opening is almost proportional to the temperature, and at 46 ° C, it is 15%.

Therefore, since the number of revolutions of the turbine 10 during turning is several revolutions per minute, the first function converter 25 outputs the optimum temperature set value of 30 ° C., and the optimum temperature set value is output by the comparator 26. Is added as one of the inputs. Since the bearing oil temperature detected by the bearing oil temperature detector 17 is applied to the comparator 26 as the other input, the comparator 26 outputs a temperature deviation signal of both input temperatures. Is added to the PID calculator 27. The PID calculator 27 performs an operation such as proportional (P), integral (I), and (D) on the input temperature deviation signal to output an operation signal, and the operation signal is the bearing oil temperature overshoot prevention circuit 30. Of the high-priority circuit 34 of FIG.

The temperature of the bearing oil detected by the bearing oil temperature detector 17 is further applied to the above-mentioned second function converter 31, and the optimum temperature set value of the bearing oil at this time is 30 degrees C. Therefore, the switching contact T of the first switching device 32 is switched to the side of the fixed contact a opposite to the one shown in the drawing, and a and c are connected. Therefore, the output of the second function converter 31 becomes an irrelevant value in terms of control and is ignored.
The minimum opening limit value of the bearing oil temperature control valve 21 set to 0
% Is applied to the high price priority circuit 34 as the other input.

Therefore, the high price priority circuit 34 passes and outputs the operation signal which is the output of the PID calculator 27 having a high value, and this operation signal is output to the low value priority circuit 44 of the bearing oil cooling water overflow prevention circuit 40. , As one of the inputs.

In the bearing oil cooling water overflow prevention circuit 40, the fixed contacts b and a of the second switch 42 are respectively connected to the maximum opening of the bearing oil temperature control valve 21 from the first opening setter 41. The limit value of 50% and the fully open opening value of the bearing oil temperature control valve 21 from the second opening setting device 43 are added. The optimum temperature setting value of the bearing oil at this time is 30
Since it is C and the rotation speed of the turbine is 3500 rpm or less, the switching contact T is switched to the fixed contact b side as shown in the drawing, and is connected between b and c. Therefore, 50% is applied to the low value priority circuit 44 as the other input.

In this way, the low value priority circuit 44 is
The operation signal which is the output of the PID calculator 27 is added as one of the inputs, and the maximum opening limit value 50% of the second opening setting device 41 is added as the other input.

In this case, since the operation signal has a maximum opening limit value of 50% or less, it is output as a low value through the low value priority circuit 44 and is output to the bearing oil temperature control valve 21. Then, the opening degree of the bearing oil temperature control valve 21 is controlled by this operation signal, and the bearing oil cooler 13 is supplied with an appropriate amount of bearing oil cooling water. At this time, since the turbine 10 is turning and its rotation speed is 800 rpm or less, the temperature of the bearing oil is controlled to 30 ° C., which is the optimum temperature set value and is suitable for turning.

Next, the turbine 10 departs from turning, starts at the point S, speeds up sequentially, its rotation speed reaches 800 rpm, and when the speed further increases, the bearing oil output from the first function converter 25 is increased. The optimum temperature set value of is also gradually increased from 30 degrees C according to the rotation speed. As the optimum temperature set value of the bearing oil rises, the temperature of the bearing oil is temperature-controlled to follow the optimum temperature set value with a time delay, and the temperature gradually rises. Furthermore, the rotation speed of the turbine is increased to 3500 rpm, which is almost 95% of the rated speed.
When reaching the vicinity, the first function converter 25 outputs 46 degrees C as the optimum temperature setting value of the bearing oil.

Thus, the rotation speed of the turbine 10 is 35
When it reaches 00 rpm or the optimum temperature setting value of the bearing oil reaches 46 degrees C, the switching contactor T of the second switching device 42 is switched to the fixed contact a side opposite to that shown in the drawing, and a-c.
The connection is established. Therefore, the opening set value input to the low value priority circuit 44 is from 50% of the maximum opening limit value of the first opening setter 41 to 10% of the fully opened opening value of the second opening setter 43.
Since it is switched to 0% and this fully open opening value of 100% is input, the opening restriction of the bearing oil temperature control valve 21 is released.

The left part of FIG. 2 shows the bearing oil temperature (curve a) and its optimum temperature set value (curve b) in the temperature control of the bearing oil from the turning of the turbine 10 to the vicinity of the end of the start control. 3), the left side portion of FIG. 3 shows the maximum opening limit value (curve c) and the minimum opening limit value (curve d) of the bearing oil temperature control valve 21 in the above temperature control.
Is shown.

In this way, the optimum temperature setting value of the bearing oil is 43 ° C. or less, or the rotational speed of the turbine 10 is 350.
At 0 rpm or less, the opening of the bearing oil temperature control valve 21 is limited to 50% of the maximum opening limit value. Therefore, even if the operation signal of the output of the PID calculator 27 exceeds 50%, it is low. Due to the action of the value priority circuit 44, the opening of the bearing oil temperature control valve 21 is not controlled to be opened beyond the maximum opening limit value of 50%, and the overflow of the bearing oil cooling water is prevented.

When the turbine 10 further accelerates beyond 3500 rpm, the temperature of the bearing oil also rises above 43 ° C. Therefore, the bearing oil temperature control valve 2 depending on the bearing oil temperature 2
The output of the second function converter 31 which outputs the optimum opening degree signal of 1 also gradually increases from 0 in accordance with the temperature rise of the bearing oil,
This output is added to the first switch 32, but at this point the switching condition of the first switch 32 is not satisfied yet, so this increased output is not added to the high value priority circuit 34, It has nothing to do with temperature control.

When the rotational speed of the turbine 10 reaches its rated speed (operating speed) of 3600 rpm, the first function converter 25 sets the optimum temperature setting value of the bearing oil to 46.
Degree C is output. At this time, the temperature of the bearing oil also reaches 43 degrees C as described above, so the switching condition of the first switching device 32 (the set temperature of the bearing oil is 46 degrees C and the temperature of the bearing oil is 43 degrees C or more) is established, and the switching contact T is switched from the fixed contact a to the fixed contact b, and as shown in the drawing, bc is connected.

Therefore, the high price priority circuit 34 has the first
The function converter 31 adds the optimum opening signal of the bearing oil temperature control valve 21, which gradually increases from 0 in accordance with the temperature rise of the bearing oil. When the temperature of the bearing oil reaches 46 degrees C due to the continuous temperature control, the second function converter 31 outputs, for example, 15% as the optimum opening signal of the bearing oil temperature control valve 21. The output is applied to the high value priority circuit 34.

As described above, when the rotational speed of the turbine 10 reaches its operating speed of 3600 rpm and the first function converter 25 outputs 46 ° C. as the optimum temperature setting value of the bearing oil, the temperature of the bearing oil is increased. Is controlled to rise to the optimum temperature setting value of 46 degrees C. However, as shown in the bearing oil temperature curve a in FIG. 2, the temperature of the bearing oil rises above this optimum temperature setting value of 46 degrees C. However, the above-mentioned high value of the overshoot prevention circuit 30 increases. Due to the action of the priority circuit 34, the overshoot value is sequentially suppressed to a low value, and eventually the temperature of the bearing oil settles at the optimum temperature set value of 46 degrees C.

The temperature control of the bearing oil from turning of the turbine 10 to starting and operation has been described above. Next, the control when the turbine 10 is stopped will be briefly described.

In FIG. 2, when a stop command is issued to the turbine 10 from a control panel (not shown) at a point PS, the rotational speed of the turbine 10 starts to decrease, and the operating speed of 3600r.
It decreases from pm. When the optimum temperature setting value of the bearing oil decreases to 46 degrees C or less as the rotation speed of the turbine 10 decreases, the switching contact T of the first switching device 32 is switched from the fixed contact b side to the a side. And a-c are connected. Therefore, the input to the high price priority circuit 34 is switched from the optimum opening signal of the output of the second function converter 31 to the output of the minimum opening setter 33, and the minimum opening limit value 0% is input, and the bearing oil is input. The minimum opening limit value of the temperature control valve 21 is 1 as shown in the figure.
It is switched from 5% to 0%.

When the rotational speed of the turbine 10 is reduced to 3500 rpm at the point P, the switching contactor T of the second switching device 42 causes the fixed contact a as shown in FIG.
The side is switched to the side b, and bc is connected as shown in the drawing. Therefore, the opening set value input to the low value priority circuit 44 is switched from the output of the second opening setter 43 to the output of the first opening setter 41, and the maximum opening limit value 50%.
Is input, the maximum opening limit value of the bearing oil temperature control valve 21 is switched from 100% to 50% as shown in the figure.

Then, as the rotational speed of the turbine 10 decreases, the optimum temperature setting value of the bearing oil gradually decreases, and the temperature of the bearing oil is also controlled to follow the optimum temperature setting value with a time lag to decrease the temperature. It gradually drops to 30 degrees C with the set value.

As described above, the bearing oil cooling water overflow prevention circuit 40 gives priority to the low value when the optimum temperature setting value of the bearing oil is 43 ° C. or less or the rotation speed of the turbine 10 is 3500 rpm or less. The circuit 44 outputs an opening limit so that the opening of the bearing oil temperature control valve 21 does not exceed 50%. As a result, it is possible to reliably prevent the overcooling of the bearing oil due to the excessive flow rate of the bearing oil cooling water at the time of a transient change such as the start / stop of the turbine 10. Also,
By setting the opening limit of the bearing oil temperature control valve 21,
It is also possible to prevent undershoot of the bearing oil temperature due to overcooling of the bearing oil.

[0053]

The present invention has been described in detail above. However, in the turbine bearing oil temperature control device of the present invention,
A first opening degree setter for setting a predetermined maximum opening degree limit value of the bearing oil temperature control valve, and a second opening degree setter for setting a fully open opening degree value of the bearing oil temperature control valve. , The maximum opening limit value and the full-opening opening value are input, and when either the optimum temperature setting value of the turbine bearing oil or the rotational speed of the turbine is smaller than a predetermined value, the maximum opening limit value Of the turbine bearing oil or the rotational speed of the turbine is greater than a predetermined value is switched to output the full-opening opening value, and a switching device of this switching device. A bearing oil cooling water overflow prevention circuit composed of a low value priority circuit to which the output and the operation signal output of the PID calculator are input, and the opening of the bearing oil temperature control valve is controlled by the output of the low value priority circuit. Since it is controlled, PID system It is possible to easily prevent the overflow of the bearing oil cooling water regardless of the setting values of the parameters, and especially in the trial run adjustment of the turbine, without the constraint of the overflow of the bearing oil cooling water, the turbine can be easily The bearing oil temperature control can be automatically adjusted.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a turbine bearing oil temperature control device of the present invention.

FIG. 2 is a bearing oil temperature curve diagram for explaining the operation of the present invention.

FIG. 3 is a limit opening curve diagram of the bearing oil temperature control valve for explaining the operation of the present invention.

[Explanation of symbols]

 10 Turbine 10a Bearing 10 of Turbine 10 Rotational Speed Detector 13 Bearing Oil Cooler 15 Bearing Oil Pump 16 Oil Supply Pipe 17 Bearing Oil Temperature Detector 19 Bearing Oil Cooling Water Pump 20 Bearing Oil Cooling Water Pipe 21 Bearing Oil Temperature Control Valve 25th 1 function converter 26 comparator 27 PID calculator 30 bearing oil temperature overshoot prevention circuit 31 second function converter 32 first switching device 33 minimum opening setting device 34 high value priority circuit 40 bearing oil cooling water overflow Prevention circuit 41 First opening setting device 42 Second switching device 43 Second opening setting device 44 Low value priority circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G05D 23/00 A 23/19 J

Claims (1)

[Claims] 1. A turbine bearing oil cooler for cooling turbine bearing oil supplied to the bearing of a turbine with bearing oil cooling water whose flow rate is adjusted by controlling the opening of a bearing oil temperature control valve, and the turbine bearing. A bearing oil temperature detector that detects the temperature of oil and outputs the bearing oil temperature, a rotation speed detector that detects the rotation speed of the turbine and outputs the rotation speed, and the rotation speed that is input A function converter that outputs an optimum temperature set value of the turbine bearing oil depending on the rotation speed, a comparator that receives the bearing oil temperature and the optimum temperature set value, and outputs a temperature deviation signal of both inputs, A PID calculator for inputting a temperature deviation signal, performing proportional, integral, differential, etc. operations on the temperature deviation signal and outputting an operation signal for the bearing oil temperature control valve, and a predetermined setting for the bearing oil temperature control valve. A first opening degree setter for setting the maximum opening degree limit value, a second opening degree setter for setting the fully opened opening degree value of the bearing oil temperature control valve, and the first opening degree The maximum opening limit value of the setting device and the full-opening opening value of the second opening setting device are input, and at least one of the optimum temperature set value output by the function converter and the rotational speed of the turbine is input. When it is smaller than a predetermined value, the previous period maximum opening limit value is output, and at least one of the optimum temperature set value output by the function converter and the rotation speed of the turbine becomes larger than a predetermined value. A switching device which is switched to output the full-opening opening value in the previous period, the operation signal and the output of the switching device are input, and the input having the lower value of both inputs is passed to adjust the bearing oil temperature. Equipped with a low value priority circuit that outputs to the valve Turbine bearing oil temperature control device, wherein the door.