JPS6245965A - Pressure controller - Google Patents

Abstract

PURPOSE:To permit the use of an exhaust value having an ordinary capacity by allowing the propellant feeding pressure to be sharply lowered, keeping the propellant feeding pressure constant, in a propellant feeding pressure controller in the ground combustion test equipment for a rocket engine. CONSTITUTION:An imitation engine valve 10 is installed at the position close to a test rocket engine 1 in a pipe 6 for feeding propellant from a propellant feeding tank 2 into the test rocket engine 1, and said valve 10 is opened simultaneously with the engine stop, and the propellant is discharged outside, and said propellant is allowed to continue flowing-out after engine stop. A resistance control valve 11 is installed at the position close to the tank 2 in the pipe 6, and said valve 11 is throttle-controlled in the period in which propellant continues flowing in the pipe 6 by the valve 11. Further, in the pipe for connecting between a pressurized-gas cylinder 3 and the tank 2, a pressurization control valve 4 which is PID-controlled through a control circuit 20 according to the detection signal of a pressure detector 8 is installed, and the propellant feeding pressure is kept constant.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a pressure control device for controlling propellant supply pressure (hereinafter referred to as interface pressure) applied to a ground combustion test facility for a rocket engine, and in particular to a pressure control device for controlling propellant supply pressure (hereinafter referred to as interface pressure). It relates to a means for rapidly descending.

[Prior art]

In recent ground combustion tests of rocket engines, in order to confirm performance under actual on-location and flight conditions, the interface pressure to the engine is adjusted to the steady pressure P1M (approximately 12 to 16 kl/ctn) before the engine stops.
) to low pressure PIL (approximately 3 to 6 kg/m) within a very short time (approximately 2 to 5 seconds) after the engine is stopped.

Although there is currently no control technique for rapidly reducing the interface pressure, a control means as shown in FIG. 6 can be considered as a means to meet the above requirements.

That is, the control means shown in FIG. 6 controls the pressure in the propellant tank 2 and the pressurized gas from the pump 3 in the steady state when the rocket engine 1 is in combustion. Maintain a constant pressure by controlling the pressure. Then, at the same time as stopping the engine 1, the control valve 4 is fully closed,
By opening the release valve 5, the pressurized gas in the tank 2 is released, thereby lowering the pressure of the propellant.

In FIG. 6, 6 is a propellant supply pipe, 7 is a propellant supply valve, 8 is a pressure detector, and 9 is a control device.

[Problem that the invention seeks to solve]

However, the above control means has the following problems.

(1) Since it is necessary to release a large amount of pressurized gas within a short time, the release valve 5 is used to release the gas after the normal test.
Alternatively, a large-capacity relief valve having a capacity 20 times or more of the capacity required for relief when operating as a safety device is required. It is also difficult to control such a large capacity relief valve within a short period of time.

(2) The amount of gas that should be released depends on the volume of gas in the tank 2, that is, the amount of propellant remaining in the tank 2, and this amount will differ each time depending on the test conditions. In other words, since the engine combustion time, initial charging amount, amount consumed for engine pre-cooling, etc. differ from test to test,
The amount of propellant remaining will differ each time. Originally, this type of test equipment is used to conduct tests while varying the conditions described above. Since the amount of gas to be released differs each time, it becomes extremely difficult to perform appropriate release control using the release valve 5.

(3) In connection with the problems of (1) and (2) above, it is almost impossible to conduct tests while varying the interface pressure drop rate.

It is also conceivable to replace the propellant supply valve 7 in FIG. 6 with a resistance control valve and to increase the pressure loss by narrowing down the resistance control valve 7, thereby reducing the interface pressure. However, after the engine stops, the engine internal valve 1a
is in a closed state, no propellant is flowing and no pressure loss occurs. t, 6 The above means are impossible in principle.

Therefore, the present invention aims to solve the technical problems such as (1), (2), and (3) above.

[Means for solving problems]

By performing PID control of the pressure control valve, the supply source pressure of the propellant is maintained constant by the pressurized gas. An engine simulating valve for discharging propellant to the outside is provided in the propellant supply pipe near the rocket engine, and this simulating valve is opened after the engine is stopped to continue flowing the propellant into the propellant supply pipe. Then, during the period in which the propellant continues to flow as described above, the resistance control valve provided in the piping is rapidly tightened to rapidly increase the pressure loss.

[Effect]

By taking such measures, the interface pressure can be rapidly reduced while the propellant supply source pressure is held constant, and a normal capacity relief valve can be used. Moreover, it is easy to control both resistance side valves according to the results calculated by a computer based on the required interface pressure drop pattern curve and supply pressure, and tests with arbitrary pressure drop patterns can be performed accurately. Ru.

〔Example〕

111th! 1 is a diagram showing the overall configuration of an embodiment of the present invention. Note that the same parts as in FIG. 6 are given the same reference numerals. Propellant is supplied to the test rocket engine 1 from a propellant supply tank 2 through a propellant supply pipe 6. An engine simulating valve 10 is located in the piping 6 near the engine 1.
is the provision. This engine simulating valve 10 opens at the same time as the engine 1 stops, and releases propellant to the outside. In this way, the propellant can continue to flow through the pipe 6 even after the engine is stopped. On the other hand, a resistance control valve 11 is provided in the piping 6 at a position close to the tank 2. This resistance control valve 11 allows the engine simulating valve 10 to prevent propellant from entering the piping 6.
During the period when the valve continues to flow, it is controlled to be narrowed down, and the pressure drop can be increased due to the increase in valve resistance.

Note that the pressurization control valve 4 is feedback-controlled by the propellant supply source pressure detected by the pressure detector 8 via the control circuit j@20, so that so-called PID control is performed. the result,
Propellant source pressure is kept constant.

In a state where the propellant supply source pressure is kept constant as described above, if an increase in pressure loss occurs due to the resistance control valve 11 described above, the interface pressure can be lowered by the amount of increase.

FIG. 2 is a block diagram showing a specific configuration of the control circuit 20, and FIG. 3 is a diagram showing its time chart. The configuration and operation of this control circuit 20 will be explained in detail later.

FIG. 4 is a diagram showing the operating principle of this device.

This will be explained below based on FIG. After the engine is stopped, the engine internal valve 1a is closed and the propellant is released through the engine simulating valve 10, so the engine interface pressure PI (k?/cIn2) and the propellant flow rate F (m/m/
s・C], the following formula holds true.

(It is effective for piping design to select the KnO value to be approximately equal to the equivalent resistance coefficient Kg of the engine. In other words, it is a KD shop.) The pressure loss due to the supply piping 6 increases the resistance control valve outlet pressure by P2 [
kg/cIn2], p2-p, and there is a relationship with the propellant flow tF. Further, if the pressure drop caused by the resistance control valve 11 and the propellant supply source pressure are P t (kg/era'), then there is a relationship such that Cv: the valve Cv value of the resistance control valve 7 [-]. (A normal control valve is one that can control this CY value to an arbitrary value.) From equation (1), substituting equation (1)' into (2) K and solving for P2 yields the following. Substituting equation (2)' into equation (3) and solving for CY, we get 0 Considering equation (4), K1 + KD +
Since KP is a constant given by the propellant and piping, the target value of the drop pattern curve of the interface pressure Pr is P sumi −p, (t)
...If the setting is as shown in (5), the CY value is calculated by substituting this into equation (4), and the resistance control valve II is controlled according to this CV value. Pressure P! is the expected pressure drop i4 given by equation (5)? It is clear that it is possible to match the turns.

FIG. 5 shows an example in which equation (4) is calculated based on various data of an actually assumed test facility. In the example of FIG. 5, the interface pressure P! , steady pressure Pts during engine combustion
(-12,0 klF/m2) to Pr in ΔT-5 seconds
The Cv value sub-control state required for linearly lowering the Cv value to L (-3kll/cm2) is shown. It is further clear from the figure that the propellant is discharged in stream iF through the engine simulating valve \v'. In other words, it is necessary to discharge the propellant flow rate F through the engine simulating valve 10 in order to allow the propellant flow rate F to flow through the supply pipe 6 and the resistance control valve 11 even after the engine is stopped, which will be explained in detail 20. During the pressure control period T (during engine combustion, rapid pressure reduction, and maintaining low pressure),
The propellant supply source pressure P is fed back by the pressure detector 6 and compared with the set value pym@t by the PID controller 21, and by controlling the pressure control valve 4 with this signal X, the PT is always maintained. -・t and equal to -10 ~ Keep it at a constant value. The switch 22 is used to turn off the PID control and fully close the pressure control valve 4 when the pressure control is completed, that is, when the pressure control command 8P is turned off. When the engine 1 stops, the stop signal sm turns ON, and the AND element 25 outputs the dependent engine simulation valve opening signal So, and the engine simulation valve 10 opens.
continues to open until the pressure control is completed (8P is between ONO) and becomes the ridge.

The engine of the function generator 26 is stopped (Sit: ON)
Then, that time is set to 1-0, and from then on, the target interface pressure PI-P at each time t is determined according to equation (5).
1(t) is calculated. The calculation circuit 27 calculates this target interface pressure P! and the actual propellant supply source pressure Pt detected by the pressure detector 8 (as mentioned above, this is the PID
The controller 21 indicates that it is equal to the set value Pys@t, but taking into consideration errors, the actual value PT is calculated from the value of Pya@t.
More precise control can be expected by using . ) Toyoshi style (
4) Calculate the Cv value of the resistance control valve 11 to be controlled. In addition, the actual control valve changes its opening degree to control Cv.
Since the value is changed, the valve characteristic of the resistance control valve 11 is Cv=f(L)... From (6), L = f-' (Cv) -(
6) A function generator 28 is provided to provide an opening signal to the resistance control valve 1, and the switch 29 fully closes the resistance control valve 11 when pressure control is completed (i.e., SP: 0FF). It is something.

NOT element 23 is activated when pressure control is completed (that is, SP: 0
FF) This turns on the escape valve open signal BY, which causes the escape valve 5 to open. (After completion, it is necessary to not apply pressure for safety reasons.) The control circuit 20 described above can realize a control state as shown in FIG. 3, and control the interface pressure pt according to the target pressure drop curve. be able to. Note that the control circuit 20 can be easily realized using an electronic circuit or computer software. The present invention can be applied not only to rocket engine ground combustion tests, but also as a pressure control device for rapidly reducing the pressure of liquid in general plants and the like.

〔Effect of the invention〕

As detailed above, the present invention provides the following effects.

1) There is no need for a large-capacity relief valve, and only a resistance control valve and engine simulating valve of the same size as a normal propellant supply pipe are provided, so control is easy and can be achieved at low cost. It is possible. (The engine simulating valve does not work even if a discharge valve, etc. used for pre-cooling the piping and draining liquid is used.) Since the pressure reduction control of the interface pressure is not affected by the amount of propellant remaining in the tank, all test conditions are met. can be easily accommodated.

! 11) Any interface pressure drop can be dealt with by simply setting the main turn in the control circuit in advance, and there is no need to change equipment.

[Brief explanation of the drawing]

Figures 1 to 5 are diagrams showing an embodiment of the present invention. Figure 1 is a system diagram showing the overall configuration, Figure 2 is a Pronk diagram showing the configuration of the control circuit, and Figure 3 is the control circuit diagram. FIG. 4 is a diagram illustrating the operating principle of the device, and FIG. 5 is a diagram illustrating the relationship between interface pressure and time. FIG. 6 is a system diagram showing the configuration of a conventional example. DESCRIPTION OF SYMBOLS 1... Test rocket engine, 1a... Engine internal valve, 2... Propellant supply tank, 3... Pressurized gas pump, 4... Pressurization control valve, 5... Relief valve, 6... Propellant supply piping, 7... Supply control valve, 8... Pressure detector, 9... Control circuit, 10... Engine simulating valve, 1
1... Resistance control valve, 20... Control circuit. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 3 Figure 4 Procedural Amendment, In 6q, 10.1, 7□ 1, Indication of Case Patent Application No. 185544/1986 2, Name of Invention Pressure Control Device 3. Relationship with the Nagisa case to be amended Patent applicant (620) Mitsubishi Heavy Industries, Ltd. 4. Sub-agent

Claims (1)

[Claims] In a propellant supply pressure control device in a rocket engine ground combustion test facility, a means for keeping the propellant supply source pressure constant with pressurized gas by performing PID control of a pressurization control valve and supplying propellant to a rocket engine an engine simulating valve that is installed in a piping that releases propellant and continues to flow the propellant into the propellant supply piping after the engine has stopped; 1. A pressure control device comprising means for increasing pressure loss and reducing propellant supply pressure in accordance with a target pattern by narrowing a resistance control valve provided in the pressure control valve.