Browsing by Author "Torres, Alejandro"
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item ExoMars 2020 LHPs: from the concept to the flight models(47th International Conference on Environmental Systems, 2017-07-16) Prado-Montes, Paula; Campo, Saúl; García, Antonio; Torres, Alejandro; Munì, Manuela; Negri, FedericaLoop Heat Pipes (LHPs) have been selected as the cornerstone solution for the ExoMars 2020 Rover Module (RM) thermal control. The RM LHPs include the switch function provided by the Vapor Modulation concept, which guarantees the equipment survival at the extreme Mars environment. This paper describes the concept of the Vapor Modulated Loop heat Pipe (VMLHP) and its implementation to the Flight Models design, manufacturing and testing. The RM LHPs consist of four units, two of them integrated on the Service Module (SVM) and two of them on the Analytical Laboratory Drawer (ALD). Each LHP is designed to transport up to 50 W and operate at temperatures from -50 ºC to +55 ºC at the evaporator level and from -120ºC to +55 ºC at the condenser. The Pressure Regulating Valves, which provide the vapor modulation and switching function, keep the SVM at a temperature higher than 0 ºC and the ALD above -40 ºC, even during the cold Martian night. A detailed thermo-hydraulic model of the LHPs has been developed in EcosimPro and correlated to the test results. The model includes all thermal links representative of the RM and the Martian environment. Operation of each LHPs has been validated through an extensive qualification campaign. Details about the main tests in climatic chamber and in vacuum are presented in the paper. Also, the main lessons learnt during the qualification and their implementation for the flight models are described.Item Integrated Thermal Architecture based on Advanced Control Loop (ACL) with multiple evaporators and condensers(50th International Conference on Environmental Systems, 7/12/2021) Campo, Sa�l; Romera, Francisco; Kulakov, Andrei; Torres, AlejandroA highly-integrated thermal architecture based on Advanced Control Loops (ACLs) has been developed and tested. This architecture consists of a Constant Conductance Heat Pipe (CCHP) network thermally connected to two ACLs. Heat-dissipating units are mounted on the CCHP network. Each ACL has 4 independent evaporators and 4 independent condensers, in the sense that they can be coupled to independent power dissipation sources or sink conditions respectively. The CCHP network has 4 primary CCHPs and 4 spreader CCHPs which serve to equalize the heat load between the primary CCHPs. The CCHP network can be embedded in a honeycomb panel to act as an equipment panel or deck. The ACL cylindrical evaporators, without the thermal interface flanges (saddles), are embedded in dedicated bores as part of the primary CCHP extruded profiles. In this way, the overall thermal gradient between the dissipating units and the condensers is minimized by eliminating the standard bolted interface between evaporator and CCHP flanges. An extensive thermal test campaign was performed on the ACL to validate the novel thermal architecture concept, to characterize the system performance under worst-case operational conditions, and to determine the system performance envelope. The campaign included a number of tests: thermal performance (conductance and heat transfer capability) under various power conditions and with a �split� (ACLs share the thermal sink) and �nonsplit� (each ACL has a dedicated thermal sink) condenser design, minimum and maximum power, start-up, transient input power and heat sink temperature variations, and NCG influence. To cope with transients in the power and thermal boundary conditions, an innovative method of control is also presented. Ammonia is selected as the working fluid for both CCHPs and ACLs taking into account the standard operating and non-operating temperature ranges of most heat-dissipating electronics.Item Mechanically Pumped Advanced Control Loop: a Solution for High Power Platforms(50th International Conference on Environmental Systems, 7/12/2021) Campo, Sa�l; �lvarez, Jes�s; Kulakov, Andrei; Romera, Francisco; Lara, �scar; Torres, AlejandroTwo-phase mechanically pumped loops have been identified as the potential solution for the heat management of high-powered platforms, such as next generation telecommunications satellites. The proposed concept Mechanically Pumped Advanced Control Loop (M-ACL) combines the advantages of a two-phase modular thermal control system and a mechanically pumped loop. In single-phase fluid loops temperature rise in the fluid and flow rate are directly proportional to the required heat transfer rate. High cooling loads lead to a large temperature rise and high pump power. For more effective thermal transport, the single-phase loop can be replaced by a two-phase one. This allows employing the latent heat of vaporization to significantly reduce flow rates, decrease temperature gradients, and increase heat transfer coefficients. M-ACL concept has been defined after an extensive literature and patents review. It is based on the multi-evaporator, multi-condenser Advanced Control Loop (ACL) concept, which means an integrate solution for the complete thermal control of the platform. The implementation of a mechanical pump in the system means an important increase of the heat transport capability that depends on the pump pressure rise characteristic. A trade-off has been performed to define main mechanical pump and M-ACL features. Additionally, a M-ACL engineering model has been designed based on a NACPA pump from RealTechnologie AG. In this study, the detailed design is presented as well as simulation results using a thermo-hydraulic model developed in EcosimPro simulation tool.Item Thermal Control of Electronic Equipment by Using a Mini Hybrid Capillary Pumped Loop (MH-CPL)(47th International Conference on Environmental Systems, 2017-07-16) Belló-Escribano, Marta; Prado-Montes, Paula; Torres, Alejandro; Beck, FelixFlight hardware technology evolution demands increasing electronic components density and electronic components power density in Printed Circuit Board´s (PCB), leading to higher temperature to the nearby components and local over-temperatures in the junction semiconductor. This has an impact to the reliability of the Electronic Semiconductor Devices (ESD) increasing the errors in digital components and forcing to reduce the current in analogue components. To overcome such a high power density, a Mini Hybrid Capillary Pumped Loop (MH-CPL) has been developed in the frame of ESA Technology Research Program to prove its heat evacuation capability on Electronic Semiconductor Devices allowing better PCB efficiency. The MH-CPL concept has been defined based on an extensive literature and patents review and it has been validated through simulation in EcosimPro. The developed concept premises have been applied to the design of a MH-CPL Engineering Model (EM), currently within manufacturing process. The EM consists of a two-phase heat transport device with four evaporators, one remote compensation chamber (RCC), common liquid and vapor lines and one condenser. A characterization test campaign in ambient and in vacuum has been defined. Main performance tests have also been simulated via EcosimPro. Predictions’ results are presented and discussed in the paper.Item Thermal Control System for Low Noise Amplifiers based on Loop Heat Pipes(46th International Conference on Environmental Systems, 2016-07-10) Prado Montes, Paula; Mishkinis, Donatas; Corrochano, Javier; Torres, Alejandro; Lapensée, StéphaneThe thermal control of current telecommunications satellites is limited by the fact that the Low Noise Amplifiers (LNA) are installed close to the antenna feed sources and dedicated radiators are accommodated near the LNA. That implies reduced radiating areas and unfavorable radiating environments. The use of Loop Heat Pipes (LHPs) for the LNA thermal control allows delocalization of the radiator, while providing an efficient link with the dissipating unit and avoiding the use of expensive and heavy structures for radiators protection, which are used today. A thermal control system based on LHPs (LNA-LHP) has been developed. The LNA-LHP concept was defined based on an extensive and detailed trade-off with main drivers the operation at low temperatures, close to -40 ºC, and at wide heat transport capability ranges, from 6 W to 175 W. As a result, the LNA-LHP was designed including two condensers in parallel, each one connected to a dedicated radiator (i.e. North and South). The flow in the loop is directed to the radiator facing the coldest environment thanks to the operation of a capillary blocker. Also, the flow can be redirected by the activation of Pressure Regulating Valves (PRV). In symmetric conditions (i.e. equinox) the flow is shared between both radiators. PRV can be included for temperature regulation at evaporator level. Thanks to the LNA-LHP system flexibility, radiators can be located at any place of the spacecraft. To provide scalability, the heat spreading over the radiator is performed via Arterial Heat Pipes. The LNA-LHP concept has been validated through simulation in EcosimPro and testing, with the thermal characterization in vacuum of a representative Engineering Model. The successful results prove that the system is able to provide the thermal control for at least four applications in current telecommunications satellites, being extendable for Earth observation, scientific and other missions.