RU2757510C1 - Heat removal system for testing electric rocket engines - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to bench tests of electric rocket engines. The heat removal system for testing electric rocket engines in vacuum chambers simulating the space environment includes a heat-dissipating cooled screen and a chiller. The heat-dissipating screen is made in form of a massive disk with at least one tube coiled to it. A coolant is placed inside the tube. The heat-dissipating screen has a diameter to completely overlap the diameter of accelerated beam emitted by the engine.

EFFECT: increase of heat removal efficiency is achieved.

8 cl, 2 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to bench tests of electric rocket engines.

PRIOR ART

An electric rocket engine (ERE) in the prior art means a rocket engine, the principle of operation of which is based on the conversion of electrical energy into directed kinetic energy of accelerated particles. In this case, a particle is understood as an atom or ion, of which the EJE jet is composed.

EJEs are classified according to the predominant particle acceleration mechanism.

There are the following types of motors: electrothermal, electrostatic motors, high-current (magnetoplasma, magnetodynamic) motors, impulse motors, etc.

During bench tests of an EJE, the problem of heat removal from the test chamber arises, since the heat fluxes of accelerated particles escaping during the operation of the engine have a destructive effect on the test chamber, the measuring instruments and the EJE installed in it. In the prior art, heat is understood as the energy that a body receives or loses in the process of heat exchange with the environment.

In the prior art, heat removal was realized by supplying cooling agents (water, air, etc.) directly into the chamber, or by installing special means, for example, heat exchangers, into the chamber.

In accordance with the patent RU2209751, a device for testing a spacecraft with a heat removal system, including an intermediate heat exchanger, in front of which a bypass valve is installed, is presented. The inlet of this valve is in communication with the payload fluid path, the first outlet - with the system fluid path after the heat exchanger outlet, and the second outlet - with the heat exchanger inlet. The ground cavity of the heat exchanger is communicated through hydraulic connectors with the ground system for ensuring the thermal regime during testing. This ground-based system provides the specified removal of excess heat and is located outside the thermal pressure chamber, in which the spacecraft is placed. The invention is aimed at simplifying the process and device for testing satellites, as well as reducing material costs and time during testing.

Utility model patent CN209142420 discloses a heat removal system installed in a test chamber and including a cylindrical body radiator, a liquid inlet manifold, a liquid outlet manifold parallel to the inlet manifold, a plurality of pipes along the side wall of the radiator cylinder housing, located in the axial direction of the radiator cylinder housing, where the lower ends of the pipes are in communication with the fluid inlet pipe, and the upper ends of the pipe are in communication with the outlet pipe and ribs located between the pipes and bent to form grooves. Such a heat sink has a high absorption capacity and a more ideal heat dissipation effect for test equipment to simulate the space environment.

The disadvantages of this technical solution include the complexity of the design of the heat removal system, as well as the need for the initial design of the test chamber with a double casing and a system for circulating the coolant between the inner and outer casing. This approach significantly increases the cost of the test chamber, its volume, the materials of the chamber must be protected from possible corrosion caused by the coolant, and the tightness between the casings must be ensured.

The closest technical solution is disclosed in patent RU2614454 for a reverberation chamber for bench tests of spacecraft rocket engines, including stationary plasma ones. The heat removal system includes a circular-shaped cooled screen installed in the reverberation chamber and connected to a closed-type circulation cooling system. The function of this screen is to convert the kinetic energy of a directed flow of charged particles into thermal energy and remove it.

Unfortunately, the description of the patent does not indicate what material the cooled screen is made of, as well as what it is structurally, therefore it is difficult to judge the efficiency of heat removal from the test chamber.

All of the above disadvantages of the known technical solutions present certain technical problems for testing an electric propulsion engine.

DISCLOSURE OF THE INVENTION

The objective of the invention is to increase the test time of the EJE and increase the service life of the chamber by improving the efficiency of heat removal during the EJE test.

The problem is solved by a heat removal system when testing electric rocket engines in vacuum chambers simulating the space environment, including a heat-removing cooled screen made of a heat-conducting metal or alloy, installed in a vacuum chamber, and a chiller installed outside the vacuum chamber and connected to the heat-removing screen through supply pipelines of the cooled heat carrier and removal of the warmed heat carrier, while the heat-removing screen has a diameter size that makes it possible to completely overlap the diameter of the beam of accelerated particles emitted by the engine at the installation site of the said screen, where the said heat-removing screen is made in the form of a massive disk attached to it coiled into a spiral, according to at least one tube with a coolant placed inside the tube.

In particular embodiments of the invention, the problem is solved by a system in which the heat sink is made of copper or a copper-based alloy.

In other particular implementations of the system's invention, the electric rocket engine is a magnetoplasma engine.

In this case, the accelerated particles are plasma particles.

The heat sink can be installed in a vacuum chamber with side flanges, and the heat sink can be fixed in said side flanges.

The system can be equipped with a hydronic module connected to the chiller and including a pumping group, an expansion tank, differential pressure regulators and collectors of heated and cooled heat carrier.

In this case, the pipelines for supplying the cooled heat carrier and withdrawing the warmed heat carrier are connected at one end, respectively, to the collectors of the insulated heat carrier and the cooled heat carrier, and at the other end are connected to the opposite ends of the coiled tube.

In particular embodiments of the system, the coolant is silicone oil or ethylene glycol.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a diagram of the claimed heat removal system when testing electric rocket engines in vacuum chambers.

FIG. 2 is a diagram illustrating the placement of the heat sink in the chamber.

The numbers in the drawings mean the following

1. Heat shield

2. Test vacuum chamber

3. Chiller

4. Pipeline for supplying the cooled heat carrier

5. Pipeline for removal of the heated heat carrier

6. Coiled tube

7. Massive disk

8. Electric rocket engine

9. Hydro module

10. Expansion tank

11. Pumping group

12. Accumulation tank

13. Chilled heat carrier collector

14.Heated heat carrier collector

15. Side flanges.

CARRYING OUT THE INVENTION

As shown in FIG. 1, the claimed heat removal system during testing of electric rocket engines includes a heat-removing shield (1) installed in the chamber (2), a chiller (3), which is understood as an apparatus for cooling a liquid using a vapor compression or absorption refrigeration cycle and pipelines connecting the chiller and the shield supply of cooled (4) and removal of warmed (5) heat carrier.

The heat sink (1) is a tube (tubes) (6) coiled into a spiral, fixed on a massive disk (7). Both the tubes and the disc are made of metal or alloy with good heat transfer properties and are pressed against each other as much as possible to ensure maximum contact area.

Ideally, the screen (1) can be made of copper or copper-based alloys, for example, L96 brass (zinc content is from 2.8 to 5 wt%, the rest is copper and impurities). The coolant is located inside the tube (6).

It is essential that the screen (1) has a diameter size that makes it possible to completely overlap the diameter of the beam of accelerated particles emitted by the engine (8) at the installation site of the said screen. This means that a screen of a relatively small diameter to completely cover the beam of accelerated particles can be placed closer to the engine, where the value of the beam diameter is smaller, and the screen of a larger diameter, farther from the engine, depending on the type of tests being performed. Thus, a uniform distribution of heat over the surface of the heat sink is realized, the access of heat to the walls of the test chamber and the devices placed in it is minimized, and effective heat dissipation is also ensured.

The screen (1) can be placed in relation to the engine (8) in the test chamber (2) either by a massive disk (7) or by a tube (6).

In particular embodiments of the invention, it is advisable to install the screen (1) in relation to the engine (8) with a massive disk (7) (see Fig. 1), which provides more effective protection of the tube (6) with the coolant, as well as the inner space of the chamber (2) - the main heat from the beam of accelerated particles enters the massive disk, and the coolant circulating in the tube (6) effectively removes heat energy from the disk (7).

The chiller (3) includes a refrigeration machine with all the main elements: a compressor, a condenser, a throttling device and an evaporator (not shown). Depending on the cooling capacity and type, the chiller can be equipped with various additional accessories.

The claimed system may include a hydronic module (9) connected to a chiller (3), which circulates a cold / heated heat carrier and contains such elements as an expansion tank (10), a pump group (11), an accumulation tank (12) (in case of insufficient volume coolant in the hydraulic circuit), as well as the collectors of the cooled coolant (13) and the heated coolant (14).

As the heat carrier circulating in the system, various heat carriers, including water, can be used. The chiller (3) is installed outside the vacuum test chamber (2). If the chiller (3), for example, is installed in an unheated room or outdoors, then it is advisable to use silicone oil (heat capacity more than 1.5 kJ / kg⋅K) or ethylene glycol (heat capacity about 5 kJ / kg⋅K) as a heat carrier. The latter, due to its high heat capacity, also removes heat most efficiently.

The circulation of the coolant is carried out as follows. The heat carrier coming from the chiller (3) through the collector of the cooled heat carrier (13) is supplied to the flexible pipe for supplying the cooled heat carrier (4) and through it enters the tube / tubes (6), then heat is taken from the heat sink (1) by heating the heat carrier in tube (6) when a plasma jet is emitted by the engine. Then the heated coolant returns to the chiller (3) through the heated coolant outlet pipeline (5), one end of which is connected to the tube (6), and the other to the heated coolant collector (14), and the process is repeated.

If the tests of the electric rocket engine (8) are carried out in a vacuum chamber (2) with side flanges (15) (see Fig. 2), then the heat-removing shield can be fixed in these flanges, which is very convenient for routine inspection and maintenance of the exhaust system warmth. The ends of the pipes (6) can also be led out through the side flanges (15) (Fig. 2) and connected, respectively, with the pipelines (4, 5) outside the test chamber. It is also possible that the ends of the pipes (6) remain in the chamber (2), and through the side flanges (15), the pipelines for supplying and removing the coolant (4, 5) enter the chamber.

With the removal of thermal energy (heat) released during engine operation, the factor of the possibility of destruction of the test chamber and its sealed joints with rubberized sealed inserts is eliminated due to the general thermal heating of the test chamber.

An example of implementation of the invention.

A magnetoplasma rocket engine (8) was installed in a vacuum chamber (2). In the process of forming a system for removing incoming heat from a running engine, a heat-removing shield (1) was mounted, consisting of a massive disk (7) and a tube (6) coiled into a spiral and soldered to the disk. The size of the diameter of the screen (1), depending on the location of the screen in the chamber, made it possible to completely block the incident beam, thereby absorbing the heat released by the tested magnetoplasma rocket engine.

The heat-removing shield (1) was made of copper and installed in the chamber (2) so that the massive disk (7) was placed on the side of the engine (8).

The inlet and outlet of copper pipes (6) through pipelines (4, 5) and collectors (13, 14) were connected to a powerful chiller (3) with a refrigerating capacity of 33 kW.

The external chiller unit (3) with coolant cooling was moved outside the room to create comfortable temperature conditions inside the laboratory, and the chiller control unit was placed inside the laboratory.

During the tests, a plasma beam (25 kW) emitted by a magnetoplasma rocket engine (8) falls on a heat-removing screen (1), which is installed so that it completely blocks the incident beam and thereby absorbs the released heat.

Ethylene glycol with a heat capacity of 3.90 kJ / (kg * K) was used as a heat carrier.

The conducted tests of the electric rocket engine showed that the time of the engine life tests was increased to 100 hours of continuous engine operation.

Claims (8)

1. The system for heat removal during testing of electric rocket engines in vacuum chambers simulating the space environment, including a heat-removing cooled screen made of a heat-conducting metal or alloy, installed in a vacuum chamber, and a chiller installed outside the vacuum chamber and connected to the heat-removing screen through pipelines for supplying a cooled coolant and removal of the insulated heat carrier, while the heat-removing shield has a diameter size that makes it possible to completely overlap the diameter of the beam of accelerated particles emitted by the engine at the installation site of the said shield, where said heat-removing shield is made in the form of a massive disk with at least one tube with a coolant placed inside the tube. 2. The system of claim. 1, wherein the heat sink is made of copper or a copper-based alloy. 3. The system of claim. 1, in which the electric rocket engine is a magnetoplasma engine. 4. The system of claim 3, wherein the accelerated particles are plasma particles. 5. The system of claim. 1, in which the heat sink is installed in a vacuum chamber with side flanges, and the said shield is fixed in the said side flanges. 6. The system according to claim 1, which is equipped with a hydronic module connected to the chiller and including a pumping group, an expansion tank, differential pressure regulators and collectors of the insulated heat carrier and cooled heat carrier. 7. The system according to claim 6, in which the pipelines for supplying the cooled heat carrier and withdrawing the insulated heat carrier are connected at one end to the collectors of the insulated heat carrier and the cooled heat carrier, respectively, and at the other end are connected to the opposite ends of the coiled tube. 8. The system of claim. 1, wherein the heat transfer fluid is silicone oil or ethylene glycol.

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