JPH10333541A - Compressor model for training simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a rise of a computer load and to improve simulated precision by numerically computing simultaneous equations made by being a process value of gas flowing into a compressor and characteristic values of various valves provided on the input/output of the compressor as variables and using plural functions and outputting the output process values of the compressor. SOLUTION: An inlet shut-off valve a3 shutting off an inlet of natural gas and a pipe volume a4 cushioning a pressure of natural gas are provided on a inlet pipe a2 connecting a BOG compressor a1 with an LNG tank. On the other hand, a check valve a6 , an outlet control valve a7 , etc., are provided on an outlet pipe a5 connecting the BOG compressor a1 with a discharge gas pipe. Then, when the process operation of the compressor a1 is simulated by numerically computing, the simultaneous equations made by being the process value of the gas flowing into the compressor a1 and the characteristic values (K values) of various valves a3 , a6 , a7 ... provided on the input/output of the compressor a1 as the variables and using plural functions related tot he output process values are solved by numerically computing, and the output process values of the compressor a1 is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compressor model for simulating the process operation of a compressor in a training simulator for simulating the operation of a plant including the compressor.

[0002]

2. Description of the Related Art A training simulator is used to train a trainee in how to operate a plant. This training simulator realizes the movement of the plant according to the operation of the trainee by installing a simulation program for simulating the movement of the plant in a computer.

[0003] For example, when a trainee learns the operation method of an LNG base as a kind of plant, a training simulator that simulates the movement of the LNG base is used. The training simulator in this case is a process model (numerical model) that simulates the process operation of each process device (LNG tank, vaporizer, various compressors, etc.) at the LNG base.
And a control model for controlling the process operation of the process model.

[0004] Here, the LNG base converts the LNG unloaded from the LNG ship and stored at a low temperature in the LNG tank into LNG.
The LNG is pumped out by a pump, the LNG is vaporized using a plurality of vaporizers, and is sent to the thermal power plant as natural gas. At the LNG terminal, natural gas obtained by natural vaporization of LNG in the LNG tank is also sent to the thermal power plant together with natural gas output from the vaporizer. In this case, in the LNG tank, LN
Natural gas generated by natural vaporization of G is compressed by, for example, a compressor, and sent to a thermal power plant together with the natural gas output from the vaporizer. In addition, at the LNG terminal, natural gas generated in various parts of the facility due to vaporization of LNG is subjected to compression processing by various compressors.

[0005] The process model of the training simulator for the LNG base is based on the process of the entire LNG base by simulating the process operation of various process equipment constituting the LNG base, such as the LNG tank, the vaporizer, and the compressor. Implement the operation. Conventionally, such a training simulator is dedicated to training, and thus does not sufficiently realize an actual plant operation. That is, the process model does not accurately simulate the actual process operation of the plant.

[0006]

As described above, the process model of the conventional training simulator does not have sufficient performance, so that training based on the faithful operation of the process equipment cannot be performed. There was a problem that training according to the actual plant could not be performed. Under such circumstances, users have requested the development of a training simulator capable of performing training closer to an actual plant. On the other hand, when a process model closer to an actual plant, that is, a process model with high simulation accuracy is realized, there is a problem that a load on a computer increases, so that cost increases and real-time training becomes difficult.

[0007] The present invention has been made in view of the above-mentioned problems, and has the following objects. (1) To provide a compressor model of a training simulator with high simulation accuracy. (2) To provide a compressor model of a training simulator capable of suppressing an increase in load on a computer. (3) To provide a compressor model of a training simulator capable of suppressing an increase in cost.

[0008]

In order to achieve the above object, in a compressor process model of a training simulator for simulating a process operation of a compressor by numerical operation, a process value of a gas flowing into the compressor and a compressor process model are described. Simultaneous equations consisting of a plurality of functions related to output process values with the characteristic values (K values) of various valves provided at the input and output of
Means of solving by numerical operation and outputting the output process value of the compressor is applied. Further, in the above means, when an input signal indicating an abnormal state of the compressor is input, a means for correcting and calculating an output process value according to the input signal is applied. Further, a means is applied in which a process value of an auxiliary machine connected to the compressor is numerically calculated and output.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a compressor model of a training simulator according to the present invention will be described with reference to FIGS. In addition, the LNG terminal is provided with a vaporizer for forcibly vaporizing LNG stored in the LNG tank and a BOG compressor for compressing natural gas (BOG) generated by natural vaporization in the LNG tank, as a schematic configuration. The natural gas output from the BOG compressor and the vaporizer is supplied to a power plant via a gas supply pipe.

The present embodiment is a training simulator used for operation training of an LNG terminal constituted by process equipment such as an LNG tank, a vaporizer, a gas supply pipe, and a BOG compressor. The BOG compressor relates to a process model (BOG compressor model) of the BOG compressor.

First, with reference to FIG.
The input / output signals of the G compressor model A will be described. As shown in the figure, the BOG compressor model A uses an operation signal and a multifunction signal as input signals, and numerically calculates an output process value of the BOG compressor based on these input signals to obtain a gas transmission pipe model ( (The process model of the gas supply pipe).

The operation signal includes a control model (a numerical model simulating a control device for controlling the movement of a process device).
And a process model (LN) of the LNG tank for feeding natural gas to the BOG compressor.
G tank model). The multifunction signal is a signal for instructing the BOG compressor model A to simulate an abnormal operation state of the BOG compressor.

When the process signal is input from the LNG tank model, the BOG compressor model A performs a numerical operation on the various process values described above and outputs it to the gas supply pipe model as a process signal.

Next, details of the process equipment simulated by the BOG compressor model A of the present embodiment will be described. In an actual LNG base, the BOG compressor is provided with some accessories, and the BOG compressor model A simulates the operation of the BOG compressor including these accessories. As shown in this figure, an inlet pipe a2 for connecting the BOG compressor a1 and the LNG tank is provided at an inlet of the BOG compressor a1, and an inflow of natural gas is shut off to the inlet pipe a2. And a piping volume a4 for buffering the natural gas pressure.

On the other hand, at the outlet of the BOG compressor a1,
An outlet pipe a5 for connecting the OG compressor a1 to the gas supply pipe is provided. The outlet pipe a5 has a check valve a6 for preventing a backflow of natural gas and an outlet control valve for controlling an output flow rate of the natural gas. a7 and the outlet cutoff valve a8 are inserted in series. At the outlet of the BOG compressor a1, a mini-flow pipe a9 is provided in parallel with the outlet pipe a5. The mini-flow pipe a9 controls the flow rate of natural gas flowing through the check valve a10 and the mini-flow pipe a9. The mini-flow valves a11 and a12 to be controlled are interposed in series.

Further, the BOG compressor a1 includes
A cooling water pump a13 for circulating cooling water for cooling the OG compressor a1 and a lubricating oil pump a14 for circulating lubricating oil for the BOG compressor a1 are provided. The BOG compressor model A simulates the operation of the BOG compressor a1 including the operation of these various auxiliary machines.

Here, for example, the following operation signals are inputted to the BOG compressor a1. Inlet pipe pressure (pressure of natural gas flowing from the LNG tank to the inlet pipe a2, a process signal output from the LNG tank model). Inlet pipe gas temperature (the temperature of natural gas flowing into the inlet pipe a2 from the LNG tank and a process signal output from the LNG tank model). A compressor start signal for instructing start of the BOG compressor a1. A valve opening signal (a signal defining the opening of the outlet control valve a7). A cooling water pump activation signal for instructing activation of the cooling water pump a13. Cooling water flow. A lubricating oil pump activation signal for instructing activation of the lubricating oil pump a14.

The BOG compressor model A performs a numerical operation described below based on each of the operation signals and the multifunction signal to numerically calculate an output process value of the BOG compressor a1 and outputs it as a process signal. For example, the output process values output from the BOG compressor model A are as follows.

[Natural gas flowing in and out] a. Inlet flow rate (flow rate of natural gas at the inlet of the inlet pipe a2). b. Outlet pipe pressure (pressure at the outlet of outlet pipe a5). c. Outlet flow rate (flow rate of natural gas flowing through the outlet pipe a5). d. Mini-flow tube pressure (pressure at outlet of mini-flow tube a9). e. Mini flow rate (flow rate of natural gas flowing through mini flow pipe a9).

[About BOG compressor a1] f. Polytropic efficiency (compression efficiency of BOG compressor a1). g. Polytrope head (compression characteristics with respect to rotation speed of BOG compressor a1). h. Compressor outlet pressure (pressure at outlet of BOG compressor a1) i. Compressor outlet gas temperature (natural gas temperature at outlet of BOG compressor a1). j. Drive current of the BOG compressor a1. k. Vibration amount of the BOG compressor a1. m. The lubricating oil temperature of the BOG compressor a1. n. Pressure of lubricating oil of BOG compressor a1. o. The pressure of the cooling water of the BOG compressor a1. p. The flow rate of the cooling water of the BOG compressor a1.

Next, the operation of the BOG compressor model A will be described with reference to the flowchart shown in FIG. This flowchart shows a procedure for numerically calculating each of the process signals.

[Step S1] In the BOG compressor model A, first, the above valves, that is, the inlet cutoff valve a3 and the check valve a
6, a10, the outlet control valve a7, the outlet shut-off valve a8, and the mini-flow valves a11 and a12 have the K opening (the flow rate of natural gas flowing through the valves is calculated by the square root of the pressure difference (differential pressure) before and after the valves). (The value obtained by the division) is calculated based on the function F1 shown in the equation (1). [K value] = F1 {Valve opening signal, K value at full opening, Malfunction signal} (1)

That is, in a state where the multifunction signal is not input, that is, in a state where the BOG compressor model A simulates a normal operation of the BOG compressor a1, the K value is [valve opening signal] and [K value at full opening]. ] Is used as a variable, and in an abnormal state where a multifunction signal is input, the [valve opening signal], [K value at full opening], and [malfunction signal] are variables. Numerical operation is performed by the function F1.

[Step S2] Subsequently, the following equations (2) to
By solving the simultaneous equations (simultaneous ordinary differential equations) relating to (7), the above [Polytropic efficiency], [Polytrope head] and [Compressor outlet pressure] relating to the operating characteristics of the BOG compressor a1 are calculated, and the inlet Tube a2
, The [inlet flow rate] of the natural gas in the outlet pipe a5, and the [mini flow rate] of the natural gas in the miniflow pipe a9 are calculated.

[Polytropic efficiency] = F2 ｛Inlet flow rate, compressor start signal｝ (2) [Polytrope head] = F3 ｛Inlet flow rate, compressor start signal｝ (3) [Compressor outlet pressure] = F4 ｛Polytrope efficiency , Polytrope head, inlet pipe gas temperature, inlet pipe pressure, compressor start signal｝ (4) [Inlet flow rate] = F5 ｛outlet flow rate, mini flow rate｝ (5) [Outlet flow rate] = F6 ｛outlet pipe pressure, Mini flow pipe pressure, compressor outlet pressure, K value｝ (6) [mini flow rate] = F7 ｛Outlet pipe pressure, mini flow pipe pressure, compressor outlet pressure, K value｝ (7)

[Step S3] Subsequently, the calculated [inlet flow rate] of the natural gas in the inlet pipe a2 is
In order to simulate the operation of the BOG compressor a1, it is determined whether or not it is smaller than the previously stored [surge generation flow rate]. This [surge generation flow rate] corresponds to the BOG compressor a
1 indicates the limit value of the inlet flow rate at which normal operation is possible. That is, the determination in step S3 is "N
In the case of “o”, an abnormal amount of natural gas is
Is in the abnormal state flowing into step S4.
Is performed.

[Step S4] That is, in this case, the [drive current] and the [vibration amount] of the BOG compressor a1 are calculated based on the model formula at the time of abnormality. For example, this model formula is obtained by functions F8 and F9 shown in the following formulas (8) and (9). [Drive current] = F8ＦPolytropic efficiency, polytrope head, outlet flow rate, multifunction signal｝ (8) [Vibration amount] = F9 ｛simulation time, multifunction signal｝ (9) Also, the above equation (4) , (6), the following equation (1) is used with the [compressor outlet pressure] and [outlet flow rate] as variables.
Based on (0) and (11), [outlet pipe pressure] and [outlet flow rate] when the BOG compressor a1 operates abnormally are corrected and calculated. [Outlet pipe pressure] = F10 {Compressor outlet pressure according to equation (4)} (10) [Outlet flow rate] = F11 {Outlet flow rate according to equation (6)} (11)

[Step S5] On the other hand, if the determination in step S3 is "Yes", the BOG compressor a1
Of [drive current] and [vibration amount] are calculated based on the following equations (8) 'and (9)' in which the multifunction signal is not included as a variable in equations (8) and (9).
The values during normal operation of the G compressor a1 are calculated. [Drive current] = F8 '{polytropic efficiency, polytrope head, outlet flow rate} (8)' [Vibration amount] = F9 '{simulation time} (9)' where the BOG compressor model A is a numerical value This is the time when the operation is being performed.

[Step S6] Subsequently, the process values relating to the auxiliary equipment are numerically calculated as follows. First, the amount of the natural gas in the pipe volume a3 (the amount of the substance in the pipe volume) is determined based on a function F12 in which the [inlet flow rate] and [outlet flow rate] of the natural gas shown in the following equation (12) are variables. Is calculated. [Material content in piping volume] = F12 {inlet flow rate, outlet flow rate} (12)

The [inlet pressure] (the pressure at the inlet of the natural gas at the inlet pipe a2) and the [outlet temperature] (the temperature of the natural gas at the outlet pipe a5) are the same as the above [the amount of material in the pipe volume]. Is calculated from the various process amounts calculated. That is, [inlet pressure] is calculated based on a function F13 having [inlet pipe gas temperature] and [material amount in pipe volume] as variables as shown in Expression (13), and [outlet temperature]
Is a function F with [Polytropic efficiency], [Inlet pipe gas temperature] and [Outlet pressure] as variables as shown in equation (14).
It is calculated based on 14. [Inlet pressure] = F13 ｛inlet pipe gas temperature, amount of substance in pipe volume… (13) [Outlet temperature] = F14 ｛polytropic efficiency, inlet pipe gas temperature, outlet pressure｝ (14)

[Step S7] Finally, as shown in the following equation (15), the [lubricating oil temperature] is set to [cooling water flow rate], [lubricating oil pump start signal], and [malfunction signal] as variables. The [lubricating oil pressure] is calculated based on the function F16 using the [lubricating oil pump start signal] and [malfunction signal] as variables as shown in equation (16), and [cooling]. Water pressure] is the formula (1
As shown in 7), it is calculated based on the function F17 having the [cooling water pump start signal] and [malfunction signal] as variables, and the [cooling water flow rate] is calculated as shown in equation (18). It is calculated based on a function F18 having the pump start signal and the multifunction signal as variables.

[Lubricating oil temperature] = F15 ｛cooling water flow rate, lubricating oil pump start signal, multiple function signal｝ (15) [lubricating oil pressure] = F16 ｛lubricating oil pump start signal, multiple function signal｝ (16) [ [Cooling water pressure] = F17 ｛Cooling water pump start signal, Malfunction signal｝ (17) [Cooling water flow rate] = F18 ｛Cooling water pump start signal, Malfunction signal｝ (18)

That is, in step S7, since the Malfunction signal is used as a variable, the temperature of the lubricating oil pump a14 or the lubricating oil is determined based on the temperature of the lubricating oil. The pressure is numerically calculated. The cooling water pressure and flow rate of the cooling water pump a13 are also numerically calculated.

In this way, finally, as process values, [polytropic efficiency], [polytrope head],
[Compressor outlet pressure], [Inlet flow rate], [Outlet flow rate],
[Mini flow rate], [Drive current], [Vibration amount], [Material amount in piping volume], [Inlet pressure], [Outlet temperature], [Lubricant oil temperature], [Lubricant oil pressure], [Cooling water pressure] ] And [cooling water flow rate], the processing in the BOG compressor model A ends.

[0035]

As described above, according to the compressor model of the training simulator according to the present invention, the following effects can be obtained. (1) In a compressor process model of a training simulator that simulates a process operation of a compressor by numerical calculation,
Simultaneous equations consisting of a plurality of functions relating to the output process value with the process value of the gas flowing into the compressor and the characteristic value (K value) of various valves provided at the input and output of the compressor as variables are calculated by numerical calculation. Since the output process value of the compressor is output by unraveling, the simulation accuracy can be improved. (2) When an input signal indicating an abnormal state of the compressor is input, the output process value is corrected and calculated in accordance with the input signal, so that the process model of the compressor in the normal state and the process model of the compressor in the abnormal state Therefore, it is not necessary to provide the two process models, and therefore, it is possible to suppress an increase in the load on the computer and an increase in cost.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an input / output relationship of a compressor model in an embodiment of a compressor model of a training simulator according to the present invention.

FIG. 2 is an explanatory diagram illustrating process equipment simulated by the compressor model in one embodiment of the compressor model of the training simulator according to the present invention.

FIG. 3 is a flowchart showing a procedure of a numerical operation in the compressor model in one embodiment of the compressor model of the training simulator according to the present invention.

[Explanation of symbols]

 A BOG compressor model a1 BOG compressor a2 Inlet pipe a3 Inlet shut-off valve a4 Pipe volume a5 Outlet pipe a6, a10 Check valve a7 Outlet control valve a8 ... Outlet shutoff valve a9 ... Mini flow pipe a11, a12 ... Mini flow valve a13 ... Cooling water pump (auxiliary equipment) a14 ... Lubricating oil pump (auxiliary equipment)

Claims (3)

[Claims] The present invention relates to a compressor process model of a training simulator for simulating a process operation of a compressor by a numerical operation, wherein a process value of gas flowing into the compressor and various valves provided for input and output of the compressor are provided. A simultaneous simulator comprising a plurality of functions relating to an output process value having a characteristic value (K value) as a variable is solved by a numerical operation to output the output process value of the compressor. model. 2. The compressor model of the training simulator according to claim 1, wherein when an input signal indicating an abnormal state of the compressor is input, an output process value is corrected and calculated according to the input signal. Training simulator compressor model. 3. The compressor model of a training simulator according to claim 1, wherein a process value of an auxiliary machine connected to the compressor is numerically calculated and output. .