JPH0643441Y2 - Pressure control device for cold heat generation equipment - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a delivery gas pressure control device for use in cold heat power generation equipment such as LNG cold heat power generation equipment.

[Prior Art] As a direct expansion reheat type delivery gas pressure control system in a conventional LNG cold heat power generation facility, there is a configuration shown in FIG. That is, after the received LNG 1 is boosted by the booster pump 2, it is vaporized by the carburetor 4 through the LNG flow rate control valve 3 into gas, and the high-pressure gas leaving the carburetor 4 is controlled by the regulator valve 5. After being expanded by the high-pressure turbine 6, it is heated by the reheater 7 and further expanded by the low-pressure turbine 8 to drive the generator 9 to generate electricity, while the gas expanded by the low-pressure turbine 8 is generated. Is heated to room temperature by the heater 10 to become the delivery gas 11. Further, the pressure of the delivery gas 11 is controlled as follows according to the demand on the gas consuming side. First, the delivery gas pressure controller 12 outputs a control signal a to the LNG flow controller 13 as an LNG flow rate command so that the pressure becomes constant with respect to the change in the pressure of the delivery gas 11, so that the LNG flow rate becomes that value. The LNG flow rate controller 13 issues an opening / closing command for the flow rate control valve 3 to adjust the LNG flow rate. As a result, the turbine inlet pressure changes, so that the turbine inlet pressure is kept constant. The pressure controller 14 issues an opening / closing command for the regulating valve 5. As a result, the gas flow rate passing through the turbines 6 and 8 is changed, the delivery gas flow rate is changed, and the pressure of the delivery gas 11 is controlled.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional method, a change in the delivery gas flow rate with respect to a change in the pressure of the delivery gas 11 occurs as a result of the control of the change in the turbine inlet pressure. May be delayed for changes. Further, when the cold heat power generation facility is operated in parallel with another vaporizer, or when the delivery gas pipe is long and has a large gas volume, the above delay is absorbed, but it is 1: 1 with the gas consumption side. When the piping of the delivery gas is short, for example, when the fuel gas of the adjacent LNG thermal power plant is supplied by one series of cold thermal power generation equipment, the delay of the delivery gas amount causes a large variation of the delivery gas pressure. However, there is a problem that the requirement on the gas consumer side cannot be satisfied.

Therefore, the present invention seeks to improve the followability with respect to changes in the delivery gas pressure.

[Means for Solving Problems] In order to achieve the above-mentioned object, the present invention vaporizes LNG and directly passes it through an expansion turbine to generate electric power, and when a delivery gas having a constant pressure is delivered to a consumer, the delivery is performed. In the pressure control device of the cold thermal power generation facility that controls the gas pressure and the turbine inlet pressure, add the control signal sent from the delivery gas pressure controller to the LNG flow controller to the control signal from the turbine inlet pressure controller. To do so, a control comprising a first-order lag element added to the control signal from the delivery gas pressure regulator, a differentiator, and an adder for adding the signal from the differentiator to the control signal from the turbine inlet pressure regulator. The arithmetic unit is made profitable, and the signal arithmetically processed by the control arithmetic unit is sent to the control valve on the turbine inlet side.

[Operation] The LNG flow controller adjusts the LNG flow rate with the control signal from the delivery gas pressure controller in response to the change in the delivery gas pressure, and at the same time, the control signal is sent from the turbine inlet pressure controller by the control arithmetic unit. The control signal is added to the control signal, and the opening and closing of the regulator valve is adjusted by the signal processed by the control processor. As a result, the delivery gas pressure control is added to the turbine inlet pressure control by the regulator valve, whereby the delivery gas amount delivered through the turbine can be changed more quickly and the delivery gas pressure controllability can be improved.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Like the conventional method shown in FIG. 3, LNG 1 is boosted by a booster pump 2 and led to a carburetor 4 through a flow rate control valve 3 where the gas is fed. As a result, the pressure is increased by the high pressure turbine 6 through the regulator valve 5, and the reheater 7 is further expanded.
Through the low-pressure turbine 8 and is heated by the heater 10 to be delivered, and the pressure of the delivery gas 11 is detected by the delivery gas pressure controller 12, and is controlled by the control signal a from the controller 12 so as to be constant. Is issued and this control signal a is LNG
LNG sent to the LNG flow controller 13 that detects the flow rate and detected
From the turbine inlet pressure regulator 14 which detects the turbine inlet pressure and outputs the control signal b so as to be constant in a configuration in which the control signal a is used as a flow rate command for the flow rate to adjust the flow rate adjusting valve 3. Instead of directly opening and closing the control valve 5 by the control signal b, the control signal b from the turbine inlet pressure regulator 14 and the control signal a from the delivery gas pressure regulator 12 are input. Thus, the control arithmetic unit 15 for arithmetically processing both control signals a and b is provided, and the control arithmetic unit 15 adjusts the regulator valve 5.

An embodiment of the control arithmetic unit 15, the delivery gas pressure regulator 12 and the turbine inlet pressure regulator 14 connected thereto is as shown in FIG. The delivery gas pressure controller 12 includes a delivery gas pressure detector 121 for detecting the delivery gas pressure and a subtractor 1.
22, delivery gas pressure setter 123, delivery gas pressure regulator 1
24, the value of the delivery gas pressure detected by the delivery gas pressure detector 121 and the set value from the delivery gas pressure setter 123 are compared by the subtractor 122, and the delivery gas pressure adjuster 124 is set to PI.
The calculation is performed and the control signal a is output. The turbine inlet pressure controller 14 is a turbine inlet pressure detector 14
1, a subtractor 142, a turbine inlet pressure setter 143, and a turbine inlet pressure adjuster 144, and the turbine inlet pressure value detected by the turbine inlet pressure detector 141 and the setting from the turbine inlet pressure setter 143. The value is compared with the subtractor 142, and the turbine inlet pressure regulator 144 performs PI calculation and outputs it as a control signal b.

The control arithmetic unit 15 characterizing the present invention includes a first-order lag element 151 added to the control signal a from the regulator 124 of the delivery gas pressure regulator 12, a differentiator 152, a signal from the differentiator 152, and the turbine. An adder 153 for adding the control signal b from the inlet pressure controller 14 to the control signal a, a first-order lag element 151 is added to the control signal a, and a differentiator 152 performs a differential operation to increase or decrease only when the input signal changes. As a signal, turbine inlet pressure regulator
The signal b from the controller 144 of 14 is added by the adder 153, and the signal obtained by the addition is used to open / close the regulator valve 5.

When the delivery gas pressure is controlled according to the change in demand on the gas consumption side, first, the delivery gas pressure controller 12 outputs a control signal a so that the pressure is constant with respect to the delivery gas pressure change. This signal a is used as an LNG flow rate command, and a control signal, that is, an opening / closing command of the flow rate control valve 3 is issued by the LNG flow rate controller 13 so as to have that value. This adjusts the LNG flow rate. On the other hand, the control signal b is issued as an opening / closing command of the regulator valve 5 by the turbine inlet pressure regulator 14 so that the pressure becomes constant with respect to the turbine inlet pressure.
The control signal a of 12 is also taken into the control arithmetic unit 15 and combined with the control signal b of the turbine inlet pressure regulator 14 to open / close the regulator valve 5 at the same timing as the opening / closing of the flow rate adjusting valve 3. As a result, the LNG flow rate is adjusted to change the turbine inlet pressure, and the turbine 5 is opened before the regulator valve 5 is opened or closed.
The gas flow rates of 6 and 8 can be adjusted, and therefore the delivery gas pressure can be improved with little change because the delay of the gas flow rate is small.

Although the turbine is a reheat type, it may not be a reheat type and may be combined with another type, for example, a Rankine cycle.

[Advantages of the Invention] As described above, according to the pressure control device of the cold thermal power generation facility of the present invention, it has a control operation device including a first-order lag element, a differentiator, and an adder, and the control operation device sends it. The control signal from the gas pressure regulator is added to the control signal from the turbine inlet pressure regulator.At this time, a first-order lag element is added to the control signal from the delivery gas pressure regulator, and a differential operation is performed by a differentiator. The signal is increased / decreased only when the input signal changes, and this signal is added to the control signal from the turbine inlet pressure regulator by an adder, and the signal obtained by the addition is used to control the control valve on the turbine inlet side. Since it is designed to open and close,
The responsiveness to changes in the flow rate of the delivered gas on the gas consumption side is improved, and fluctuations in the delivered gas pressure can be suppressed to a small level. In particular, fuel gas from an adjacent LNG thermal power plant is supplied by a single thermal power generation facility. When such a cold thermal power generation facility is operated on a one-to-one basis with the gas consuming side and the delivery gas piping is short, the delivery gas amount is greatly delayed and the delivery gas pressure fluctuates to satisfy the requirements on the gas consumption side. Even if there is a problem of disappearing, by controlling the turbine inlet pressure by the control valve with the signal processed by the control processing device with the above configuration, the amount of delivery gas delivered through the turbine can be changed more quickly. Thus, the controllability of the delivery gas pressure can be improved, and the effect is great, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a specific example diagram of a control arithmetic unit according to the present invention and a delivery gas pressure controller, a turbine inlet pressure controller, and FIG. It is a system diagram which shows the conventional example. 1 …… LNG, 3 …… Flow control valve, 5 …… Adjustment valve, 6 ……
High-pressure turbine, 8 ... Low-pressure turbine, 9 ... Generator, 12
...... Sending gas pressure controller, 13 …… LNG flow controller, 14…
… Turbine inlet pressure regulator, 15 …… Control computing device, 151
…… First-order lag element, 152 …… Differentiator, 153 …… Adder, a
...... Control signal from the delivery gas pressure controller, b …… Control signal from the turbine inlet pressure controller.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A cold thermal power generation facility, comprising: LNG vaporized and directly passed through an expansion turbine to generate electric power; and when the delivery gas having a constant pressure is delivered to a consumer, the delivery gas pressure is controlled and the inlet pressure of the turbine is controlled. In the pressure control device, in order to add the control signal sent from the delivery gas pressure regulator to the LNG flow controller to the control signal from the turbine inlet pressure regulator, a first-order delay added to the control signal from the delivery gas pressure regulator A control arithmetic unit including an element, a differentiator, and an adder for adding a signal from the differentiator to a control signal from the turbine inlet pressure regulator is provided, and a signal arithmetically processed by the control arithmetic unit is provided at a turbine inlet. A pressure control device for a cold heat power generation facility, wherein the pressure control device is configured to send the pressure control valve on the side.