RU2791158C1 - Method for configuration of the emergency protection system of a liquid rocket engine - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to instrumentation and measuring equipment, and can be used in rocket engineering as an emergency protection system (EPS) of liquid rocket engines (LRE). EPS is configured using adaptive configuration of the adjustable EPS parameters to the operating modes of the engine. The configuration is calculated based on the results of a check process test of the engine, wherein the values of the adjustable EPS parameters, the values of thrust, and the nominal values of external factors are selected for each operating mode thereof. The values of the adjustable EPS parameters and the values of thrust are then brought to the nominal values of external factors, and the expected dependence of the adjustable EPS parameters brought to the nominal values of external factors on the thrust brought to the nominal values of external factors is determined. For the set operating modes of the engine, the adaptive upper and lower threshold values of EPS configuration are then determined at the actual values of external factors at the entrance to the engine.

EFFECT: invention can be applied to configure the emergency protection system of LREs during operation thereof.

5 cl, 3 dwg, 4 tbl

Description

The present invention relates to instrumentation and can be used in rocket technology as an emergency protection system (SAZ) for liquid rocket engines (LRE).

One of the main components that ensures high efficiency of the SAS operation is the choice of permissible limit values of the controlled parameters of the SAS, when they are exceeded, a command for an emergency engine shutdown (EAS) is generated.

It is widely known that in the USSR the onboard emergency protection system during the flight of the launch vehicle (LV) existed only twice: for the lunar program of the N-1 launch vehicle and for the Energia launch vehicle. At the same time, the onboard SAZ of the LRE was adjusted in such a way that the limiting values of the controlled parameters of the SAZ were assigned the same for all operating modes of the LRE. Such a principle was implemented in the onboard SAZ LRE LV "Energiya" (see the book by B.I. Gubanov, "THE TRIUMPH AND TRAGEDY OF "ENERGIA" REFLECTIONS OF THE CHIEF DESIGNER" volume 3: "ENERGY" - "BURAN", Nizhny Novgorod, NIER publishing house, 1998).

The disadvantage of this approach to setting the limiting controlled parameters of the SAS was that it leads to a sharp expansion of the boundaries of the range of adjustment of the SAS of the LRE and a decrease in the efficiency of the onboard SAS of the LRE due to the possibility of timely shutdown of the engine without developing an emergency on the launch vehicle.

The objective of the invention is to create a SAZ LRE, which performs adaptive adjustment of the limit values of the controlled parameters of the SAZ to all modes of engine operation (thrust), including transient modes (forcing and throttling mode).

This problem is solved due to the fact that the adjustment of the SAZ LRE is carried out using the adaptive setting of the controlled parameters of the SAZ to the engine operating modes, for this, according to the results of the control and technological test (CTT) of the engine, for each of its operating modes, the values of the controlled parameters of the SAZ, thrust values ( R) and the values of external factors, while the nominal values of external factors are used in the calculation, then the values of the controlled parameters of the SAS are brought to the nominal values of external factors, for which, for each selected mode of engine operation, amendments to the controlled parameters of the SAS are determined by the deviation of the actual values of each external factor from its nominal value, then for each selected engine operation mode, the thrust values are brought to the nominal values of external factors by the deviation of the actual values of all external factors from their nominal values, then for all engine operation modes, the expected the calculated dependence of the external factors reduced to the nominal values of the controlled parameters of the SAZ on the external thrust factors reduced to the nominal values using the formula:

where, KP_OZH - the expected value of the controlled parameters of the SAZ;

K10, K00 - coefficients of the equation;

R-thrust

further, for the given engine operating modes (LV flight or re-fire test of the engine), using the indicated dependence, the expected values of the controlled parameters of the SAS are determined, and these values are used to determine the adaptive upper and lower threshold values for setting the SAS of the LRE at the actual values of external factors at the engine inlet .

Other differences of the proposed method are:

- for each selected engine operating mode, the values

controlled parameters of the SAZ lead to nominal values

external factors according to the following formula

where, ΔKPV_KM - correction for the value of KPV when changing the mass ratio of fuel components, rpm;

A21, A11, A00 - coefficients of the equation;

R - thrust;

KM _tech - the current value of the mass ratio of fuel components;

KM _nom - nominal value of the mass ratio of fuel components;

- for each selected mode of engine operation, the actual thrust, reduced to nominal conditions, is determined with amendments to the thrust values by the magnitude of the deviations of the actual values of external factors from their nominal values according to the formula

where, R_PR - thrust, reduced to the nominal values of external factors;

R - thrust;

ΔR_KM - correction value of thrust when changing the mass ratio of fuel components;

ΔR_DO - correction for the thrust value when the oxidizer pressure changes at the engine inlet;

ΔR_ТГ - correction for the value of thrust when the fuel pressure changes at the engine inlet;

ΔR_TO - correction for the value of thrust when the temperature of the oxidizer at the engine inlet changes;

ΔR_TT - correction for the value of thrust when the temperature of the fuel at the engine inlet changes;

- the following parameters are used as controlled parameters of the SAZ: revolutions, temperature, displacement and pressure;

- the following parameters are used as external factors: the mass ratio of fuel components, temperature and pressure of the oxidizer and fuel at the engine inlet.

An example of the implementation of the method.

As an example of the adaptive adjustment of the SAZ, let's consider an emergency firing bench test of an engine carried out at JSC NPO Energomash, where the standard emergency protection system could not turn off the engine when the fuel supply pipeline to the automation drives collapsed. The engine was turned off for 325 s when the turbopump unit shaft speed parameter - CPV reached the upper limit threshold value. Let us show that this accident could be parried by the adaptive adjustment of the SAZ LRE according to the controlled parameter SAZ -KPV.

To carry out the adaptive adjustment of one of the controlled parameters of the SAZ-KPV according to the results of the carried out KTI of a commercial engine, for each of the 39 stationary modes, the following are selected: the values of the PPV, the values of thrust (R) and the values of external factors, which are summarized in Table 1:

- R - thrust values;

- KM - mass ratio of fuel components;

- DG - fuel pressure at the engine inlet, kgf/cm ² ;

- TO - oxidant pressure at the engine inlet, kgf/cm ² ;

- TG - fuel temperature at the engine inlet, °C;

- TO - temperature of the oxidizer at the engine inlet, °C;

- KPV - the value of the revolutions of the THA shaft, rpm;

The following nominal values of external factors are used in the calculation:

- nominal mass ratio of fuel components in the KM chamber nom=2.75.

- the nominal value of the pressure of the oxidizer at the inlet to the engine TO nom=5 kgf/cm ² .

- the nominal value of the fuel pressure at the inlet to the DG engine nom=2.8 kgf/cm ² .

- nominal value of the temperature of the oxidizer at the inlet to the engine

TO _nom = minus 182.5°С.

- the nominal value of the fuel temperature at the inlet to the engine TG _nom = minus 5°C.

The CPV values are brought to the nominal values of external factors and the CPV value reduced to the nominal values of external factors is determined using corrections to the CPV.

Table 2 for each of the engine operating modes shows the values of the influence of each external factor separately on the CPV and the CPV value reduced to the nominal values of external factors.

The thrust values are brought to the nominal values of external factors and the thrust value reduced to the nominal values of external factors is determined using corrections to the thrust values.

Table 3 for each of the engine operating modes shows the values of the influence of each external factor separately on the thrust value and the thrust value reduced to the nominal values of external factors.

In FIG. 1 for all modes of engine operation, the expected dependence of the external factors of CPV reduced to the nominal values on the external factors of thrust reduced to the nominal values is shown. The resulting dependence of the expected CPV values on thrust is given in formula 1.

where, CPV_OZH - expected value of CPV.

For a given thrust profile shown in FIG. 2, determine the adaptive upper and lower limit values for setting the emergency protection system according to the CPV.

According to the obtained dependence (1) and according to formulas (2) and (3), the adaptive limiting upper and lower threshold values of the emergency protection system setting according to the CPV are determined for the given engine operation modes.

The CPV values determined by formulas (1), (2) and (3) for different thrust levels are summarized in Table 4.

where, KPV_NN - upper limit values of KPV;

KPV_LL - lower limit values of KPV;

ΔKPV - deviation of the KPV from the expected values of the KPV;

ΔKPV_F - the influence of external factors on the KPV (mass ratio of fuel components, temperature and pressure of the oxidizer and fuel at the engine inlet).

The value of ΔKPV is 657 rpm and is determined based on:

- static spreads of controlled parameters of LRE operation depending on intra-engine factors determined by the features of LRE manufacturing;

- necessary safety margins for outliers of parameters that do not allow the formation of a false AED command.

The value of ΔKPV_F is equal to 275 rpm and is determined based on:

- specified temperature and pressure deviations of the oxidizer and fuel at the engine inlet from their nominal values;

- the maximum allowable deviation in the mass ratio of the fuel components.

In FIG. 3 in the time interval from 271 to 277 s shows the intersection of the controlled parameter of the CPV of the adaptive limiting upper threshold value of the CPV.

As can be seen from FIG. 3, the command for emergency shutdown of the engine could be generated starting from 275.23 s, i.e., by 49.77 s before the standard LRE fired.

Industrial application.

This invention can be used to set up the LRE emergency protection system (launcher rocket or stand during engine retesting) during their operation.

Claims (24)

1. A method for setting the parameters of the emergency protection system (SAZ) of a liquid-propellant rocket engine (LRE), characterized in that the setting of the SAZ of the LRE is carried out using the adaptive setting of the controlled parameters of the SAZ to the engine operating modes, for this, according to the results of a control and technological test of the engine for each of its of the operating mode, the values of the controlled parameters of the SAZ, the values of thrust (R) and the values of external factors are selected, while the nominal values of external factors are used in the calculation, then the values of the controlled parameters of the SAZ are brought to the nominal values of external factors, for which corrections are determined for each selected mode of engine operation to the controlled parameters of the CAS by the magnitude of the deviation of the actual values of each external factor from its nominal value, then for each selected mode of engine operation, the thrust values are brought to the nominal values of external factors by the magnitude of the deviation of the actual values of all external factors ov from their nominal values, then for all modes of engine operation, the expected dependence of the external factors of the controlled parameters of the SAS reduced to the nominal values on the external thrust factors reduced to the nominal values is determined using the formula:

, where KP_OZH - the expected value of the controlled parameters of the SAZ; K10, K00 - coefficients of the equation; R - thrust, further, for the given engine operating modes (LV flight or re-fire test of the engine), using the indicated dependence, the expected values of the controlled parameters of the SAS are determined, and these values are used to determine the adaptive upper and lower threshold values for setting the SAS of the LRE at the actual values of external factors at the engine inlet . 2. The method according to p. 1, characterized in that for each selected engine operation mode, the values of the controlled parameters of the SAZ lead to the nominal values of external factors according to the following formula

, where ΔKPV_KM - correction for the value of KPV when changing the mass ratio of fuel components, rpm; A21, A11, A00 - coefficients of the equation; R - thrust; KM _tech - the current value of the mass ratio of fuel components; KM _nom - nominal value of the mass ratio of fuel components. 3. The method according to claim 1, characterized in that for each selected mode of engine operation, the actual thrust, reduced to nominal conditions, is determined with amendments to the thrust values by the magnitude of the deviations of the actual values of external factors from their nominal values according to the formula

, where R_PR - thrust, reduced to the nominal values of external factors; R - thrust; ΔR_KM - correction value of thrust when changing the mass ratio of fuel components; ΔR_DO - correction for the thrust value when the oxidizer pressure changes at the engine inlet; ΔR_DG - correction for the thrust value when the fuel pressure changes at the engine inlet; ΔR_TO - correction for the value of thrust when the temperature of the oxidizer at the engine inlet changes; ΔR_ТГ - correction for the value of thrust when the temperature of the fuel at the engine inlet changes. 4. The method according to p. 1, characterized in that the following parameters are used as controlled parameters of the SAS: revolutions, temperature, displacement and pressure. 5. The method according to claim 1, characterized in that the following parameters are used as external factors: the mass ratio of the fuel components, the temperature and pressure of the oxidizer and fuel at the engine inlet.

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