• Bulletin of the Korean Space Science Society
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• 2005.04a
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• pp.129-132
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• 2005

This paper describes BAUSAT-2 orbital thermal analysis and preliminary design of thermal control subsystem. To design thermal control subsystem of HAUSAT-2, we have considered active & passive thermal control method based on basic theory and themal equilibrium equation. Using this result, suitable thermal control method and material have been selected. We have designed thermal control subsystem based on analysis of HAUSAT-2's thermal environments on sun synchronous orbit with altitude 650km, inclination $98^{\circ}$ and thermal distribution and range expectation of each HAUSAT-2's surface. Thermal analysis consists of system level, box level and board level analysis. We have completed system level and box level analysis. Till now, board level analysis of main heat dissipation board in progress. Thermal control subsystem has designed according to thermal analysis result. This design is to maintain all of the HAUSAT-2 components within the allowable temperature limits. In future, STM

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.7
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• pp.632-641
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• 2000

The present study concerns the simulation of supply-air control in a variable air volume (VAV) system. A stratified lumped thermal model (multi-zone model) is suggested to predict local thermal response of an air-conditioned space. The effects of various thermal parameters such as the cooling system capacity, the thermal mass of air-conditioned space, the time delay of thermal effect, and the building envelope heat transmission are investigated in detail. Further, the influence of control parameters, PI control factor and the sensor location on a VAV system is quantitatively delineated. The results obtained show that the previous homogeneous lumped thermal model (1-zone model) may predict a significantly different thermal response in the air-conditioned space according to the sensor location.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.3
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• pp.46-56
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• 2001

The present study concerns the numerical simulation of a supply airflow control in a variable air volume (VAY) system. A stratified thermal model (multi-zone model) is suggested to predict a local thermal response of an air-conditioned space. The effects of various thermal parameters such as the cooling system capacity, the thermal mass of an air-conditioned space, the time delay of thermal effect, and the building envelope heat transmission are investigated. Further, the influence of control parameters such as the supply air temperature, the PI control factor and the thermostat location on a VAV system is quantitatively delineated. The results obtained show that the previous homogeneous lumped thermal model (single zone model) may overestimate the time taken to the set point temperature. It is also found that there exist the appropriate ranges of the control parameters for the optimal airflow control of the VAV system.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.1
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• pp.10-16
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• 2003

The present study performs an experimental measurement on transient thermal response of an air-conditioned space by a variable air volume (VAV) system with a PI(pro-portional-integral) control logic. A thermal chamber with a PI controlled VAV unit is constructed to verify the previously suggested stratified multi-zone model. The effects of thermal parameters and control parameters such as supply air temperature and PI control factor are investigated by implementing the thermal chamber test. The experimental results obtained show that transient behavior of the air-conditioned space-temperature is in good accordance with the simulation results of the stratified thermal model.

• Journal of Astronomy and Space Sciences
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• v.29 no.1
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• pp.23-31
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• 2012

Thermal analysis and control design are prerequisite essential to design the satellite. In the space environment, it makes satellite survive from extreme hot and cold conditions. In recent years CubeSat mission is developed for many kinds of purpose. Triplet Ionospheric Observatory (TRIO)-CubeSat for Ion, Neutral, Electron, MAgnetic fields (CINEMA) is required to weigh less than 3 kg and operate on minimal 3 W power. In this paper we describe the thermal analysis and control design for TRIO-CINEMA mission. For this thermal analysis, we made a thermal model of the CubeSat with finite element method and NX6.0 TMG software is used to simulate this analysis model. Based on this result, passive thermal control method has been applied to thermal design of CINEMA. In order to get the better conduction between solar panel and chassis, we choose aluminum 6061-T6 for the material property of standoff. We can increase the average temperature of top and bottom solar panels from $-70^{\circ}C$ to $-40^{\circ}C $ and decrease the average temperature of the magnetometer from $+93^{\circ}C$ to $-4^{\circ}C$ using black paint on the surface of the chassis, inside of top & bottom solar panels, and magnetometer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.2
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• pp.91-97
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• 2002

The present study concerns an experiment on the supply-air control in variable air volume (VAV) system with a Pl control logic. A thermal chamber with a Pl control logic is constructed to verify the previously suggested multi-zone model. The stratified thermal model is adopted in the control logic for a thermal chamber cooling test. The effects of taler- mal parameters and control parameters such as supply air temperature and Pl control factor are investigated by implementing the thermal chamber cooling test. The experimental results obtained show that the transient behavior of the air-conditioned space temperature are in good agreement with the simulation results of the stratified thermal model.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.77-80
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• 2002

Thermal analysis has been performed to evaluate the thermal effect on composite antenna (Ka-band) structure in space environment. The concepts of thermal control are also presented to maintain the antenna components within respective temperature limits. A steady-state algorithm of I-DEAS' thermal analysis software was utilized to predict both maximum and minimum temperature, maximum gradient temperature, and temperature distribution on each antenna component.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.526-534
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• 2016

A MEMS solid propellant thruster array shall be operated within an allowable range of operating temperatures to avoid ignition failure by incomplete combustion due to a time delay in ignition. The structural safety of the MEMS thruster array under severe on-orbit thermal conditions can also be guaranteed by a suitable thermal control. In this study, we propose a thermal control strategy to perform on-orbit verification of a MEMS thruster module, which is expected to be the primary payload of the STEP Cube Lab mission. The strategy involves, the use of micro-igniters as heaters and temperature sensors for active thermal control because an additional heater cannot be implemented in the current design. In addition, we made efforts to reduce the launch loads transmitted to the MEMS thruster module at the system level structural design. The effectiveness of the proposed thermo-mechanical design strategy has been demonstrated by numerical analysis.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.229-234
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• 2002

Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.12
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• pp.1222-1228
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• 2008

A small satellite, DubaiSat-1 FM(Flight Model), which is based on SI-200 standard bus platform and scheduled to be launched in 2008, is being developed by Satrec Initiative and EIAST(Emirates Institution for Advanced Science and Technology). The TCS(Thermal Control Subsystem) of DubaiSat-1 FM has been designed to mainly utilize passive thermal control in order to minimize power consumption, but the active control method using heaters has been applied to some critical parts. Also, thermal analysis has been performed for DubaiSat-1's mission orbit using a thermal analysis model. The thermal design is modified and optimized to satisfy the design temperature requirements for all parts according to the analysis result. The thermal control performance of DubaiSat-1 FM is verified by thermal vacuum space simulation, consisting of thermal cycling and thermal balance test. Also, to validate the thermal modeling of DubaiSat-1 FM, comparison of test results with analysis has been performed and model calibration has been completed.