Outer Space Simulation Test Chamber
Thermal vacuum test system
The Outer Space Simulation Test Chamber and Thermal Vacuum Test System of Grande Electronics Technology Limited are applied to simulate the outer space,space, environmental testing for satellite products . The temperature range could reach -180℃ ~+200 ℃,and Max. pressure to 1×10﹣6Pa. Even it could be installed an artificial sun to simulate the light environment in space. Our company adopts the internationally advanced heat sink temperature Cutting-edge Heat sink temperature technology control,transfer the temperature,and make the uniformity more excellent, can meet the U.S. army standard space test standards.
Main Technology Parameters
(1) Ultimate vacuum: better than 1×10﹣5Pa
(2) Working vacuum:better than 1.3×10﹣4Pa
(3) Temperature range: ﹣180℃~200℃
(4) Temperature Accuracy：±0.5℃
(5) Temperature of the heat sink: ≤100K
(6) Uniformity of heat sink temperature: ≤±5℃
(7) Black paint for inner wall of heat sink, Absorption of sunlight by heat sink≥0.95 Hemispheric emittance≥0.90, The outer surface is equipped with radiation shield.
(8) Infrared heating heat flux density 100W/m2~1800W/m2。
(9) With vacuum degree and temperature measurement function
The vastness of space is both familiar and strange to human. Familiar, because manned space activities have been carried out for decades, man has been into space hundreds of times. Strange, because the space environment is so complex, that every manned space activities, is still full of numerous changes and great risks. Facing the complicated and changeable environment of manned spaceflight, the astronauts can successfully complete the mission of manned spaceflight only when they make full preparation of test and training on the earth. Ground test and training cannot be separated from simulation technology simulation equipment.As to understand the simulation technology and simulation equipment, first of all should understand the manned space environment
1,Vacuum environment and simulation
The spacecraft is in orbit at the altitude of 500 km, the vacuum of space is about 10-6 pa. At orbit altitude of 1000 km, the vacuum of space is about 10-8 pa. During the thermal simulation test of spacecraft and Eva spacesuit space environment(Mainly heat vacuum test and heat balance test), The main concern is the influence of vacuum environment on the thermal characteristics of the specimen. When the vacuum reaches more than 10-2 bar, Radiant heat transfer has become the main form of heat transfer. The effects of convection and conduction are negligible. Therefore, the vacuum degree of space simulation equipment reaches 10-3 bar, the heat exchange effect in the vacuum environment of spacecraft orbit has been simulated, so do not have to go for higher vacuum. There are only some special tests, such as vacuum dry friction test and cold welding test, are required to provide higher vacuum test equipment
2,Solar irradiation environment and simulation
The sun radiates enormous energy into space all the time. The wavelengths of sunlight cover a wide area from10-14 M（γgamma rays） to 14 meters (gamma rays) to 104 meters (radio waves), Different wavelengths of sunlight radiates different amounts of energy. Visible light radiates the most energy. With visible and infrared radiation accounting for more than 90 percent of the sun's total radiation energy.
In the orbit flight, the spacecraft and the Eva spacesuit mainly receive three parts of radiation energy: Energy from the sun's visible and infrared radiation 、the earth reflects energy from the sun and heat from the earth's atmosphere. The energy absorbed by spacecraft and Eva spacesuit affects its temperature and distribution. The energy absorbed depends on the surface material characteristics of its structure and shape and flight trajectory. At wavelengths less than 300 nanometers, the radiation energy is a tiny fraction of the sun's total, However, the optical properties of the material surface will be greatly changed. The ultraviolet radiation effects are mainly reflected by photochemical effects and photoquantum effects.
The solar radiation simulation test can simulate the solar spectrum thermal effect and solar spectrum photochemical effect produced by solar radiation environment on spacecraft and Eva spacesuit. If only the thermal effect is simulated, it is called outer space heat flow simulation. There are two ways to simulate heat flow outside space, one is the in-jet simulation method, also known as solar simulation method; The other is absorption heat flow simulation, also known as infrared simulation. The solar simulation method should be used for the specimen with complex shape and surface material; If the shape is regular and the surface material is single, infrared simulation method can be used. If the photochemical effect of ultraviolet irradiation environment needs to be simulated, the ultraviolet irradiation simulator can be used.
3,Space cold black environment and simulation
The equivalent temperature of the space is about 3K and the thermal absorption rate is 1, It can be thought of as an ideal black body without thermal radiation or reflection . When there is no solar irradiation, space is a completely cold and dark space . In this cold and dark environment, all the heat energy emitted by the object is completely absorbed .Therefore, it is also called heat sink environment. The cold black environment has great influence on the thermal performance of spacecraft and Eva spacesuit, To develop spacecraft and Eva spacesuit, it is necessary to conduct thermal vacuum and thermal balance tests in the simulated cold and black environment. Verify whether its thermal design and thermal performance meet the requirements
In order to simulate the space cold and dark environment, Components usually made of aluminum, copper or stainless steel. The inner surface is coated with special black paint with high absorbency and liquid nitrogen is injected into the structure. This device is called heat sink. At present, all the spaceflight countries use this kind of heat sink with liquid nitrogen as the cold source to simulate the space cold and black environment. Because the thermal analysis theory calculation and the test data analysis indicated, heat sink with 77K liquid nitrogen temperature and absorption rate above 0.9 was used to simulate the space cold and black environment, and the simulation error was only about 1%. It can fully meet the requirements of simulation test of cold and black environment. In addition, the pursuit of lower temperatures is unnecessary and will greatly increase the technical difficulties and investment in analog equipment.
Technical Parameters:
Description:Vacuum System
Application
The main components of space vehicles and other products, Performance test and reliability test are carried out under the combined action of thermal vacuum environment (hot and cold temperatures )in the thermal vacuum environment simulation equipment.
The vacuum environment test equipment is composed of the vacuum chamber,heat sin,Infrared heating cage,Electrical control and environmental parameter testing system.
Vacuum container
The empty container is a horizontal cylinder with an open gate at one end. Effective container size：φ800×1200mm。length of straight flange 1200mm
Vacuum pumping system
vacuum pumping system divided into molecular pump set coarse pumping pump for oil pump and valve pipeline and other accessories
Room temperature and space load limit pressure : ≤6.7×10-5Pa(Need to be roasted)
Low temperature no load limit pressure（≤100K）: ≤2.0×10-5Pa.(Need to be roasted)
Working vacuum : (The product is aviation plug-in) ≤5.0×10-5Pa; (Need to be roasted)
Pump-down time: 30min~1h
Cold light; Surface temperature of heat sink:5.0×10-3Pa，Start with pre-pumping≤20min；
Cold light; Surface temperature of heat sink: 5.0×10-4Pa，Start with pre-pumping≤30min；
Heat sink
effective size φ450×900mm length of straight flange
Surface temperature of heat sink : ≤200K
Homogeneity: ±5℃
Surface temperature≤+130℃，Teperature control precision，±3℃
Sample temperature range:limiting temperature-70℃～+130℃.
Control accuracy:Error ≤±1℃.
Heating rate:≥2℃/min，
Cooling rate:≥2℃/min；
Low-temperature system:mechanical refrigeration
Uninterrupted working time of equipment:more than 20 days
Separate grounding of equipment,Grounding resistance is not greater than
A power supply flange is left on the side of the test box,Pin number ≥55 core，Meet the requirement of 1000V withstand voltage 5mA leakage current
System configuration and program description
Vacuum container
The vacuum container is a horizontal cylinder with an open door at one end，One end is a butterfly head. The vacuum container and head are made of 0Cr18Ni9(304) stainless steel. The base is made of carbon steel. The welding adopts inner ring argon arc welding. Simulation of high and low temperature vacuum environment in the main tank 0 key process control of tank production.
Door flange integral heat treatment, eliminate stress
Weld color inspection, re - helium mass spectrometry leak detection, The overall leakage rate is≤1×10-6Pa.L/S；
The inner wall of the tank is polished, roughness is 0.8~1.6。barffing
leak rate≤1×10-6PaL/S。leak test plant; helium mass spectrometer leak detector
Vacuum chamber material requirements
a.material: Use 0Cr18Ni9 stainless steel plate ring system, Use 0Cr18Ni9 stainless steel disc head
b. Reference Document;
The lower half of the container is about 45 places inside, Weld main heat sink installation guide rail.
The inner lower half of the main heat sink is about 45 positions, Installed with infrared heating cage installation guide.
Container door head and bottom head under head, Welded mounting door and bottom heat sink mounting lifting block. The container is equipped with a light.
Heat-sink system
a.The red copper pipe shall be tested for 20kg compressive strength for 10 minutes and annealed before welding.
b.All stainless steel tubes are tested and screened 100%. The leakage of each branch tube after welding with fin was detected by 100% helium mass spectrometry. leak rate≤5×10-7Pa.L/S, Final assembly shall be carried out after the leakage rate is met(welding).
The main heat sink
Main heat sink is the main component of the equipment to provide low temperature environment. It can provide low temperature of ≤200K. The main heat sink is tube coil structure. In order to meet the temperature uniformity, the inner tube is divided into two channels for inlet and outlet liquid.
Main heat sink consists of 2mm thick copper plate as the main material. effective size φ450×900mm length of straight flange.
The main heat sink externally welded withφ14×1.5mm red copper pipe. The connection mode is silver welding.
The main heat sink is fixed to the external stainless steel frame. The frame is also wrapped with a 0.5mm thick stainless steel mirror plate for heat insulation shielding. It can prevent condensation or condensation from happening in the outer wall of the container at low temperature for a long time
The main heat sink is insulated with teflon between the frame. To reduce the loss of cooling capacity of main heat sink. The inner side of heat sink is installed with the installation guide rail of infrared heating cage. A fixed foot is installed on the outside side. Fixed after entering vacuum container.