JPS6323448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a plant that evaporates low-temperature liquefied fuel gas such as liquefied petroleum gas and supplies it as a gas, and particularly relates to a control device for a plant that supplies fuel to a boiler for a thermal power plant. .

Liquefied Petroleum Gas...
When a liquefied fuel gas such as LPG (hereinafter abbreviated as LPG) is used in a thermal power plant, the liquefied fuel is vaporized again and supplied to the burner in a gaseous state by controlling the fuel flow rate. FIG. 1 shows the configuration of an LPG fuel supply plant for such a thermal power plant, and its operation will be explained below.

The LPG liquid is sent from the LPG liquid tank 1 to the evaporator 3 through the LPG liquid pump. The LPG liquid in the evaporator 3 enters the reboiler 4 from the bottom of the evaporator 3, is heated by hot water in the reboiler 4, becomes an LPG vapor/liquid mixed phase liquid, and returns to the evaporator 3. A portion of the LPG vapor among the LPG vapor/liquid mixed phase liquid returned to the evaporator 3 is sent to the superheater 5, where it is superheated with hot water, becomes LPG superheated vapor, and is sent through piping to a boiler for a thermal power plant.

To control the above LPG fuel supply plant,
As a conventional example, there is an LPG fuel supply plant control device shown in FIG. Next, the operation of this LPG fuel supply plant control device will be explained.

The subtracter 101 calculates the deviation L _EVE between the LPG liquid level setting value L _EVR of the evaporator 3 and the LPG liquid level L _EV.
Calculate. The proportional/integrator 102 calculates the evaporator outlet LPG vapor flow rate correction signal _FCV3M based on the deviation _LEVE . Adder 103 calculates the evaporator outlet LPG vapor flow rate F _CV3 and the evaporator outlet
The LPG vapor flow rate correction signal F _CV3M is added to calculate the evaporator inlet LPG liquid flow rate demand signal F _CV1D . The subtractor 104 is a subtractor 104 that outputs the evaporator inlet LPG liquid flow rate demand signal F _CV1D and the evaporator inlet LPG
Calculate the deviation F _CV1E from the liquid flow rate F _CV1 . The proportional/integrator 105 calculates the evaporator inlet LPG liquid flow rate control valve CV1 and the operation signal M _CV1 based on the deviation F _CV1E , and calculates the evaporator inlet LPG liquid flow rate control valve CV1.
Operate 1.

The subtractor 106 calculates the deviation P _EVE between the evaporator LPG vapor pressure set value P _EVR and the evaporator LPG vapor pressure P _EV . The proportional/integrator 107 calculates the reboiler hot water flow rate demand signal F _CV2D based on the deviation P _EVE . The subtractor 108 calculates the reboiler hot water flow rate demand signal F _CV2D and the reboiler hot water flow rate.
Calculate the deviation F _CV2E from F _CV2 . Proportional/integrator 1
09 calculates the reboiler hot water flow rate control valve CV2 operation signal M _CV2 based on the deviation F _CV2E , and operates the reboiler hot water flow rate control valve CV2.

The subtractor 110 calculates the deviation P _HE between the piping LPG steam pressure setting P _HR and the piping LPG steam pressure P _H. The proportional/integrator 111 calculates the evaporator outlet LPG vapor flow rate demand signal F _CV3D based on the deviation P _HE . The subtracter 112 is the evaporator outlet
Calculate the deviation F _CV3E between the LPG steam flow rate demand signal F _CV3D and the evaporator outlet LPG steam flow rate F _CV3 .
The proportional/integrator 113 calculates the evaporator outlet LPG steam flow rate control valve CV3 operation signal M _CV3 based on the deviation F _CV3E , and operates the evaporator outlet LPG steam flow rate control valve CV3.

The subtractor 114 calculates a deviation T _SHE between the superheater outlet LPG steam temperature set value T _SHR and the superheater outlet LPG steam temperature T _SH . Proportional/integrator 1
15 calculates the super heater hot water flow rate demand signal F _CV4D based on the deviation T _SHE . Subtractor 11
6 is super heater hot water flow rate demand signal F _CV4D
Calculate the deviation F _CV4E between the superheater hot water flow rate F _CV4 and the superheater hot water flow rate F CV4. The proportional/integrator 117 calculates the super heater hot water flow rate control valve CV4 operation signal M CV4 based on the deviation F _CV4E , and calculates the super heater hot water flow rate control valve CV4 operation signal M _CV4 .
Operate CV4.

The subtractor 118 calculates the LPG steam pressure set value P _FFR after the pressure reducing valve CV5 and the LPG steam pressure P _FF after the pressure reducing valve CV5.
Calculate the deviation P _FFE from Proportional/integrator 119
Based on the deviation P _FFE , the pressure reducing valve CV5 outlet LPG
Calculate the steam flow rate demand signal F _CV5D . The subtractor 120 outputs the LPG steam flow rate demand signal F _CV5D at the outlet of the pressure reducing valve CV5 and the LPG steam flow rate F CV5 at the outlet of the pressure reducing valve _CV5.
Calculate the deviation F _CV5E from Proportional/integrator 121
is the pressure reducing valve CV5 operation signal based on the deviation F _CV5E .
Calculate M _CV5 and operate pressure reducing valve CV5.

The subtractor 122 calculates the deviation between the fuel flow rate demand signal FRD of the boiler for thermal power plants and the fuel flow rate F _CV6 .
Calculate F _CV6E . The proportional/integrator 123 calculates the deviation
F Based on _CV6E , fuel flow control valve CV6 operation signal
Calculate M _CV6 and operate fuel flow control valve CV6.

By the way, the conventional LPG fuel supply plant is
It supplied LPG fuel not only to boilers for thermal power plants, but also to other industrial plants. For this reason,
Even if a boiler for a thermal power plant undergoes rapid load shedding operation in which the generator output is rapidly reduced from the rated load to the power plant's internal load (5 to 10% load) in about 10 seconds due to a power system failure, LPG fuel The fuel load on the supply plant subsided with only partial changes, and could be handled by the LPG fuel supply plant control system that mainly uses feedback control as described above. However, when supplying LPG fuel to boilers for thermal power plants on a one-to-one basis, When a boiler for a thermal power plant performs rapid load shedding operation, the LPG fuel supply plant also needs to significantly reduce the amount of fuel, and with conventional LPG fuel supply plant control equipment that mainly uses feedback control, there is a delay in operation and the amount of control is reduced. The problem is that it fluctuates significantly. Specifically, the rapid reduction in the fuel flow rate increases the internal pressure of the evaporator, which is unfavorable in terms of pressure-resistant design of the evaporator. In addition, the evaporator is equipped with a safety valve, and when the internal pressure of the evaporator rises to a predetermined operating pressure, this safety valve operates and the released LPG is burned in the atmosphere in a flare stack. Become. Such combustion in the atmosphere itself is unfavorable from the standpoint of environmental protection and plant safety, and even during rapid load shedding of thermal power plants, increases in evaporator pressure due to operational delays must be suppressed as much as possible.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a liquefied fuel gas supply plant control device that can suppress fluctuations in the control amount and perform good control without causing any delay in operation even during rapid load shedding operation.

The feature of the present invention is to use the fuel flow demand signal FRD or the like for a boiler for a thermal power plant in order to suppress fluctuations in the control amount and perform good control without causing any delay in operation even during rapid load shedding operation. The demand signal for each operating end is calculated based on equivalent signals, and each operating end is operated in a feedforward manner based on these demand signals.

This configuration was designed to reduce the fuel flow rate at the output end of the fuel liquefied gas supply plant during rapid load shedding operation, and as a result, the pressure reducing valve
Increase the pressure after CV5, throttle the pressure reducing valve CV5, increase the piping steam pressure, throttle the evaporator outlet steam flow control valve (CV3), increase the evaporator steam pressure, and throttle the reboiler hot water flow rate. This is to prevent a delay from occurring and a large fluctuation in the control amount. For this reason, the operation amount on the upstream side is rapidly narrowed down in synchronization with the change in the output end. By doing this, the occurrence of surges is suppressed, fluctuations in the control amount are suppressed, and
Stable control is possible.

Another feature of the present invention is that in order to minimize the pressure loss in the evaporator outlet steam flow rate control valve (CV3), which is unique to a fuel liquefied gas supply plant, the evaporator steam pressure set value ( _PEVR ) is set as the fuel flow rate demand signal. The reason is that it is given as a function of (FRD).

One embodiment of the invention is shown in FIG. As can be seen from the figure, the present invention calculates the demand signal of each operating end based on the fuel flow rate demand signal FRD of a boiler for a thermal power plant, and calculates the demand signal of each operating end in a feed forward manner based on these demand signals. It is designed to operate. Also, the evaporator internal pressure set value is given as a function of FRD. Next, an embodiment of the present invention will be described according to FIG.

In the figure, a subtracter 201 is used to calculate the fuel flow rate demand signal FRD and the fuel flow rate of a boiler for a thermal power plant.
Calculate the deviation F _CV6E from F _CV6 . Proportional/integrator 2
02 is the fuel flow control valve based on the deviation F _CV6E .
CV6 operation signal M Calculate _CV6 and control the fuel flow control valve
Operate CV6.

The subtractor 203 calculates the deviation P _FFE between the LPG steam pressure set value F _FFR after the pressure reducing valve CV5 and the LPG steam pressure P _FF after the pressure reducing valve CV5. The proportional/integrator 204 calculates a pressure reducing valve CV5 outlet LPG steam flow rate set value correction signal F _CV5RM based on the deviation P _FFE . Adder 20
5 is the pressure reducing valve CV5 outlet LPG steam flow rate demand signal by adding the LPG steam flow rate setting value correction signal F _CV5RM and the fuel flow rate demand signal FRD.
Calculate F _CV5D . The subtracter 206 is a pressure reducing valve CV5.
Outlet LPG steam flow rate demand signal F _CV5D and pressure reducing valve CV
Calculate the deviation F _CV5E from the 5 outlet LPG steam flow rate F _CV5 . The proportional/integrator 207 calculates the pressure reducing valve CV5 operation signal M CV5 based on the deviation F _CV5E , and calculates the pressure reducing valve CV5 operation signal M _CV5 .
Operate CV5.

The subtractor 208 calculates the piping LPG steam pressure set value P _HP
Calculate the deviation P _HE between and the piping LPG steam pressure P _H.
The proportional/integrator 209 generates an evaporator outlet LPG steam flow rate setting value correction signal F _CV3RM based on the deviation P _HE
Calculate. Adder 210 is connected to the evaporator outlet
LPG steam flow rate set value correction signal F _CV3RM and fuel flow rate demand signal FRD are added together, and the evaporator outlet
Calculate the LPG steam flow rate demand signal F _CV3D . The subtractor 211 calculates a deviation F _CV3E between the evaporator outlet LPG vapor flow rate demand signal F _CV3D and the evaporator outlet LPG vapor flow rate F _CV3 . The proportional/integrator 212 calculates the evaporator outlet LPG steam flow rate control valve CV3 operation signal M CV3 based on the deviation F _CV3E , and calculates the evaporator outlet LPG steam flow rate control valve CV3 operation signal M _CV3 .
Operate CV3.

The subtracter 213 calculates the deviation L _EVE between the LPG liquid level setting value L _EVR of the evaporator 3 and the LPG liquid level L _EV.
Calculate. The proportional/integrator 214 calculates the evaporator inlet LPG liquid flow rate set value correction signal F _CV1RM based on the deviation L _EVE . Adder 215 adds evaporator inlet LPG liquid flow rate setting value correction signal F _CV1RM and fuel flow rate demand signal FRD to calculate evaporator inlet LPG liquid flow rate demand signal F _CV1D . The subtractor 216 is a subtracter 216 that outputs the evaporator inlet LPG liquid flow rate demand signal F _CV1D and the evaporator inlet LPG
Calculate the deviation F _CV1E from the liquid flow rate F _CV1 . The proportional/integrator 217 calculates the evaporator inlet LPG liquid flow rate control valve CV1 operation signal M _CV1 based on the deviation F _CV1E , and operates the evaporator inlet LPG liquid flow rate control valve CV1.

Next, the subtractor 218 calculates the evaporator LPG steam pressure set value P _EVR and the evaporator LPG steam pressure.
Calculate the deviation P _EVE from P _EV . P _EVR is calculated by function generator 230 as a function of fuel demand signal FRD as shown in FIG. Proportional/integrator 21
9 calculates the reboiler hot water flow rate setting value correction signal _FCV2RM based on the deviation _PEVE . Function generator 22
0 is based on the fuel flow demand signal FRD,
Calculate the reboiler hot water flow rate setting value F _CV2R . FIG. 5 shows an example of the functional relationship between the fuel flow rate demand signal FRD and the reboiler hot water flow rate set value _FCV2R . This represents the static characteristics of F _CV2 with respect to FRD. The adder 221 outputs the reboiler hot water flow rate set value correction signal F _CV2RM and the reboiler hot water flow rate set value F _CV2R.
and reboiler hot water flow rate demand signal F _CV2D
Calculate. The subtractor 222 calculates a deviation F _CV2E between the reboiler hot water flow rate demand signal F _CV2D and the reboiler hot water flow rate F _CV2 . The proportional/integrator 223 is
Reboiler hot water flow control valve CV based on deviation F _CV2E
2. Calculate the operation signal M _CV2 and operate the reboiler hot water flow rate control valve CV2. The reason why the evaporator LPG vapor pressure set value _P This is to control the pressure P _H to a constant value and to minimize the pressure loss at the evaporator outlet LPG steam flow control valve CV3.

The subtractor 224 calculates a deviation T _SHE between the superheater outlet LPG steam temperature set value T _SHR and the superheater outlet LPG steam temperature T _SH . Proportional/integrator 2
25 calculates the super heater hot water flow rate setting value correction signal F _CV4RM based on the deviation T _SHE . Function generator 226 calculates superheater hot water flow rate set value F _CV4R based on fuel flow rate demand signal FRD. An example of the functional relationship between the fuel flow rate demand signal FRD and the superheater hot water flow rate setting value F _CV4R is shown in the sixth example.
As shown in the figure. This represents the static characteristics of F _CV4 with respect to FRD. The adder 227 adds the super heater hot water flow rate setting value correction signal F _CV4RM and the super heater hot water flow rate setting value F _CV4R to calculate a super heater hot water flow rate demand signal F _CV4D . The subtractor 228 is a super heater hot water flow rate demand signal.
Deviation between F _CV4D and super heater hot water flow rate F _CV4 F _CV4E
Calculate. The proportional/integrator 229 has a deviation F _CV4E
The super heater hot water flow rate control valve CV4 operation signal M _CV4 is calculated based on the super heater hot water flow rate control valve CV4, and the super heater hot water flow rate control valve CV4 is operated.

The embodiment of the present invention described above calculates a demand signal for each operating end based on the fuel flow rate demand signal FRD of a boiler for a thermal power plant, and operates each operating end in a feed forward manner based on these demand signals. Therefore, even during rapid load shedding operation, it is possible to suppress fluctuations in the control amount and perform good control without causing any delay in operation. That is, the fuel flow rate demand signal FRD is
01 as well as subtracter 205 and subtracter 21 respectively.
0, the subtractor 215, the function generator 230, the function generator 220, and the function generator 226 also perform calculations to obtain each demand signal or set value, so the fuel flow rate demand signal FRD is used as in the case of rapid load shedding operation. If the LPG changes in each part of the fuel liquefied gas supply plant,
It becomes possible to change the steam flow rate, hot water flow rate for evaporation and superheating in advance,
It is possible to perform good control without causing any delay in operation.

In addition, Fig. 11 is a diagram showing the configuration of the piping, and in the figure, F _H is the piping flow rate, P _H is the downstream value of the piping LPG steam pressure, and P′ _H is the upstream value of the piping LPG steam pressure. . Note that only the downstream value P _H is actually measured. FIG. 12 is a diagram showing the relationship between the piping flow rate F _H and the pressure drop ΔP _H. Here, the pressure drop ΔP _H is determined by the following formula.

ΔP _H = CF ² _H = P′ _H −P _H (C; coefficient) Figure 13 shows the pipe flow rate F _H (fuel demand signal
FRD) and evaporator LPG steam pressure set value P _EVR
FIG. In the figure, P _H is the downstream value of the pipe LPG steam pressure, P′ _H is the upstream value of the pipe LPG steam pressure, ΔP _H is the pressure drop,
ΔP _CV3 is the evaporator outlet LPG steam flow control valve
This is the pressure loss at CV3. Figure 13a shows the case where the evaporator LPG steam pressure set value P _EVR is constant, and Figure 13b shows the case where the evaporator LPG steam pressure setting value P EVR is constant.
This shows the case where the steam pressure set value P _EVR is given as a monotonically increasing function of the fuel demand signal FRD. As is clear from the comparison between Figure 13a and Figure 13b, by giving the evaporator LPG steam pressure set value P _EVR as a monotonically increasing function of the fuel demand signal FRD, the evaporator outlet LPG steam flow rate control valve CV3 Minimize pressure loss, piping
LPG vapor pressure can be controlled to a constant value.

In the embodiment described above, the fuel flow control valve CV is controlled in a feed forward manner based on the fuel flow demand signal FRD of the boiler for a thermal power plant.
6. Each valve flow rate demand signal and evaporator LPG steam pressure setting value of pressure reducing valve CV5, evaporator outlet LPG steam flow control valve CV3, evaporator inlet LPG liquid flow control valve CV1, reboiler hot water flow control valve CV2, super heater hot water flow control valve CV4 had decided. In addition, as shown in FIG. 7, the flow rate demand signal of the fuel flow control valve CV6 is determined based on the fuel flow rate demand signal FRD, and the flow rate demand signal of the fuel flow rate control valve CV6 is determined based on the fuel flow rate _FCV6 , which is equivalent to the fuel flow rate demand signal FRD. Pressure reducing valve CV5, evaporator outlet LPG steam flow control valve CV3, evaporator inlet LPG liquid flow control valve CV1, reboiler hot water flow control valve CV2, super heater hot water flow control valve CV4
Each valve flow demand signal and evaporator
An LPG steam pressure set value may also be determined. In addition, in the example of FIG. 7, the fuel flow rate demand signal FRD, the pressure reducing valve CV5 flow rate demand signal F _CV5D which is the output of the adder 305 equivalent to the fuel flow rate demand signal FRD, or the evaporator outlet based on the pressure reducing valve CV5 flow rate. LPG steam flow control valve
CV3, Evaporator inlet LPG liquid flow control valve CV
1. Each valve flow rate demand signal and evaporator LPG steam pressure setting value may be determined for the reboiler hot water flow rate control valve CV2 and the superheater hot water flow rate control valve CV4.

In addition, as another example, as shown in FIG. 8, the valve flow rate demand signals of the fuel flow rate control valve CV6 and the pressure reducing valve CV5 are determined based on the fuel flow rate demand signal FRD, and the fuel flow rate demand signal
Based on the pressure reducing valve CV5 flow rate F _CV5 equivalent to FRD,
Each valve flow rate demand signal and evaporator LPG steam pressure set value are determined for the evaporator outlet LPG steam flow rate control valve CV3, the evaporator inlet LPG liquid flow rate control valve CV1, the reboiler hot water flow rate control valve CV2, and the superheater hot water flow rate control valve CV4. Good too. In the example of FIG. 8, based on the fuel flow rate F _CV6 equivalent to the fuel flow rate demand signal FRD or the pressure reducing valve CV5 flow rate demand signal F _CV5D which is the output of the adder 405, the evaporator outlet LPG steam flow rate control valve CV3 , evaporator inlet LPG liquid flow rate control valve CV1, reboiler hot water flow rate control valve CV2, super heater hot water flow rate control valve CV4, each valve flow rate demand signal and evaporator LPG
A steam pressure set value may also be determined.

Furthermore, as another embodiment, as shown in FIG. 9, based on the fuel flow rate demand signal FRD,
The valve flow rate demand signals of the fuel flow rate control valve CV6, the pressure reducing valve CV5, and the evaporator outlet LPG steam flow rate control valve _CV3 are determined, and the evaporator inlet LPG liquid is Flow control valve CV
1. Each valve flow rate demand signal and evaporator LPG steam pressure setting value may be determined for the reboiler hot water flow rate control valve CV2 and the superheater hot water flow rate control valve CV4. In addition, in the example of FIG. 9, the fuel flow rate F _CV6 is equivalent to the fuel flow rate demand signal FRD, and the pressure reducing valve CV5 is the output of the adder 505.
Flow rate demand signal, pressure reducing valve CV5 flow rate F _CV5 , or evaporator outlet which is the output of adder 510
Evaporator inlet based on LPG steam flow rate F _CV3
The valve flow rate demand signal and evaporator LPG steam pressure setting value may be determined for each of the LPG liquid flow rate control valve CV1, the reboiler hot water flow rate control valve CV2, and the superheater hot water flow rate control valve CV4.

In addition, as another embodiment of the invention, as shown in FIG. 10, the valve flow rate demand signals of the fuel flow rate control valve CV6 and the pressure reducing valve CV5 are determined based on the fuel flow rate demand signal FRD, and the fuel flow rate demand signal is determined based on the fuel flow rate demand signal FRD. Based on the evaporator outlet LPG steam flow rate F _CV3 , which is equivalent to the signal FRD, the evaporator inlet LPG liquid flow rate control valve CV1, reboiler hot water flow rate control valve CV2,
Each valve flow rate demand signal and evaporator LPG steam pressure setting value of the superheater hot water flow rate control valve CV4 may be determined. Also, the 10th
In the example shown, based on the evaporator outlet LPG steam flow rate demand signal, which is the output of the proportional/integrator 609, which is equivalent to the fuel flow rate demand signal FRD,
Each valve flow rate demand signal and evaporator LPG steam flow rate set value may be determined for the evaporator inlet LPG liquid flow rate control valve CV1, the reboiler hot water flow rate control valve CV2, and the superheater hot water flow rate control valve CV4.

In addition, as other embodiments of the invention, fuel flow rate demand signals such as a load demand signal of a boiler for a thermal power plant, a generator output, a main steam flow rate, a boiler demand signal, a feed water flow rate, etc.
Based on the signal equivalent to FRD, evaporator outlet LPG steam flow control valve CV3, evaporator inlet
Each valve flow rate demand signal and evaporator LPG steam flow rate set value may be determined for the LPG liquid flow rate control valve CV1, the reboiler hot water flow rate control valve CV2, and the superheater hot water flow rate control valve CV4.

Further, in the embodiments of the present invention, a proportional/integrator/differentiator may be used in the portion where the proportional/integrator is used.

Furthermore, in the embodiments of the present invention, the case where the LPG fuel supply plant and the boiler for a thermal power plant correspond in a 1:1 ratio was dealt with, but when the LPG fuel supply plant and the boiler for a thermal power plant correspond in a 1:N ratio, , since the fuel flow control valve CV6 and pressure reducing valve CV5 correspond to each boiler, the fuel flow control valve CV6 and pressure reducing valve CV5 correspond to each boiler.
The demand signal for CV6 and the pressure reducing valve CV5 is the fuel flow rate demand signal FRD _i (i=1~
The demand signals and evaporator LPG steam flow rate set values for the evaporator outlet LPG steam flow rate control valve CV3, evaporator inlet LPG liquid flow rate control valve CV1, reboiler hot water flow rate control valve CV2, super heater hot water flow rate control valve CV4 are determined by Fuel flow rate demand signal FRO _i (i=1~
N) may be determined based on the sum _N 〓 ⁱ⁼¹ FRD _i or a signal equivalent to _N 〓 ⁱ⁼¹ FRD _i .

As can be seen from the above embodiments, according to the present invention, even during rapid load shedding operation, there is no delay in the operation of each part of the fuel liquefied gas supply plant, and fluctuations in the control amount are suppressed to perform good control. In particular, unnecessary pressure rise inside the evaporator can be suppressed. In addition, since the evaporator internal pressure set value is given as a function of the fuel flow demand signal FRD in consideration of the flow rate and pressure characteristics of the piping, the pressure loss at the evaporator outlet steam flow control valve (CV3) is kept to a minimum while Steam pressure can be controlled to a constant value.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an LPG fuel supply plant, FIG. 2 is an example of a conventional LPG fuel supply plant control device, and FIG. 3 is a diagram showing an embodiment of the LPG fuel supply plant control device according to the present invention. Figures 4 to 6
The figures show the characteristics of the function generator of the embodiment shown in Fig. 3, Figs. The figure shows the relationship between the pipe flow rate and the pressure drop, and FIG. 13 shows the relationship between the pipe flow rate (fuel demand signal) and the evaporator LPG steam pressure set value. 1... LPG liquid tank, 2... LPG liquid pump,
3... Evaporator, 4... Reboiler, 5... Super heater, 6... Hot water pump, CV1... LPG
Flow rate control valve, CV2... Reboiler hot water flow rate control valve,
CV4...Super heater hot water flow control valve, CV5...
...Pressure reducing valve, CV6... Fuel flow control valve, FRD...
Fuel flow rate demand signal, T _SHR ... Super heater outlet temperature set value, P _EVR ... Evaporator steam pressure set value, L _EVR ... Evaporator liquid level set value, 22
0,226,230...Function generator.

Claims (1)

[Scope of Claims] 1. The liquefied fuel gas in the evaporator is circulated to the reboiler to exchange heat with the heat medium, and the evaporated liquefied gas is heated to the superheater.
a second control valve that controls the liquid level of the evaporator by adjusting the flow rate of the liquefied gas supplied to the evaporator as a means for controlling the plant that leads the liquefied gas to the burner through the control valve; and a second control valve that controls the liquid level of the evaporator; at least a third control valve that controls the evaporator steam pressure by adjusting the amount of heat medium supplied to the superheater, and a fourth control valve that controls the superheater outlet temperature by adjusting the amount of heat medium supplied to the superheater. The second, third, and fourth control valves each receive a preceding signal corresponding to the fuel flow rate demand signal of the burner, a liquid level deviation of the evaporator, a steam pressure deviation of the evaporator, and superheater outlet steam. A control device for a fuel liquefied gas supply plant, characterized in that control is performed using a signal obtained by adding together a feedback correction signal calculated from a temperature deviation. 2. A liquefied gas supply plant for fuel, characterized in that each preceding signal described in claim 1 is calculated from a value of a liquefied gas vapor flow rate detected at any part downstream of the evaporator. Control device. 3. The liquefied fuel gas in the evaporator is circulated to the reboiler to exchange heat with the heat medium, and the evaporated liquefied gas is heated to the super heater,
a second control valve that controls the liquid level of the evaporator by adjusting the flow rate of the liquefied gas supplied to the evaporator as a means for controlling the plant that leads the liquefied gas to the burner through the control valve; and a second control valve that controls the liquid level of the evaporator; a third regulating valve that controls the evaporator steam pressure by adjusting the supply amount of the heat medium; a fourth regulating valve that controls the superheater outlet temperature by regulating the supply amount of the heat medium to the superheater; The second, third, fourth, and fifth control valves are provided at the outlet of the evaporator and control the steam pressure of the piping from the evaporator to the superheater to a predetermined value. The control valves each perform a feedback correction calculated from a preceding signal corresponding to the fuel flow rate demand signal of the burner, a liquid level deviation of the evaporator, a steam pressure deviation of the evaporator, a superheater outlet steam temperature deviation, and a piping steam pressure deviation. liquid gas for fuel, characterized in that the pressure setting value for calculating the vapor pressure deviation of the evaporator is a function of the preceding signal corresponding to the fuel flow rate demand signal. Supply plant control equipment.