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Cryogenic Chemical Dynamic Power Systems

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Cryogenic Chemical Dynamic Power Systems

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By: Nirresh Prabu A/L Ravindran

In the chemical dynamic power system, a fuel and oxidizer are reacted to produce a high temperature gas , which is then expanded through a prime mover driving an electrical alternator to produce required power. For low duration missions and power levels, a monopropellant, such as hydrogen peroxide or hydrazine may be used to produce the hot gas. However, once an appreciable total power requirement is reached, a bipropellant  reaction must be used. Liquid hydrogen as the fuel and liquid oxygen as the oxidizer have received the most attention.

The hydrogen- oxygen combustion reaction possesses a number of characteristics which makes it  quite a desirable for this application. Since the combustion products are rich in hydrogen, they have a low molecular weight, producing a low specific propellant consumption for a given temperature. The reducing nature of the combustion gases is also advantageous from a materials standpoint.

One of the major disadvantages of the cryogenic chemical dynamic system is the storage problem created by cryogenic propellants. In addition, the low density of hydrogen tends to produce large volumes.

website:https://books.google.com.my/books?id=fV7y6lPL5RgC&pg=PA67&lpg=PA67&dq=chemical+dynamic+power+systems&source=bl&ots=SS-4C7feVH&sig=B-z1XjrZlsn4kS3x3tLEHitRacM&hl=en&sa=X&ved=0ahUKEwi508KtxNDZAhXCE7wKHQ8vC9YQ6AEINzAD#v=onepage&q&f=true

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Dynamic systems with alternator - Stirling Engine 

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Dynamic systems with alternator - Stirling Engine 

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By: Teo Chen Lung

The stirling concept consists of two isotope heat source modules surrounded by multifold thermal insulation, two stirling engines driving electrical alternators , and housing that act as the primary structure . Isotope heat vaporizes a salt under pressure to drive a steam turbine and electrical generator. The working temperature is around 600'C to 700'C  on the hot side and 100'C to 120'C on the cold side
The stirling technology demonstration prototype has been built and tested successfully on the ground. It used a linear alternator for rated electrical power output of 55W at 90V and 80Hz frequency. The alternator output was electronically converted into 28V  d.c suitable for use on the spacecraft.
The reliability can be an issue in such concepts with only two engines. If one fails, the other becomes overloaded unless both are designed for delivering full power, which would result in a heavy mass penalty. For this reason, the number of stirling engines in practical system designs is likely to be four. The total specific power of a few hundred watts power source with a matching converter is estimated to be around 8 to 10 W/kg in two engine systems and 4 to 5 W/kg in four engine systems

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By : Linghan Samanaseh

Solar Dynamic power systems concentrate sunlight into a receiver where the energy is transferred to a heat engine for conversion to electrical power. Brayton heat engines utilize a turbine, compressor, and rotary alternator to produce power using an inert gas working fluid. A schematic diagram of the CBC system is shown in Figure 1. The heated fluid from the receiver is expanded through a turbine, cooled through a heat exchanger where waste heat is transferred to a liquid coolant, and pressurized in a compressor before being re-heated by the solar receiver. A recuperative heat exchanger between the turbine discharge and receiver inlet is often used to improve cycle efficiency. Waste heat transferred to the liquid coolant, is dissipated via radiator panels to space. The rotary alternator typically provides three phase, alternating current (ac) at about 1 khz to the power management and distribution for electrical conversion (if needed) and distribution to the spacecraft bus.

Source :  A Solar Dynamic Power Option for Space Solar Power

Website: https://www.researchgate.net/publication/24325485_A_Solar_Dynamic_Power_Option_for_Space_Solar_Power

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by: ZULARIEFF REDZWAN

Advantages of Nuclear - Dynamic spacecraft power system for Deep Space Surveillance System (DSSS)

1) Flies in any orbit without modifictaion
2) Performs continuous scan, stare, or other motions
3) Insensitive to normal or enhanced Van Allen radiation
4) Nuclear and laser hard
5) Reduced visibility to optical or radar search
6) Maneuverable with minimal warning time
7) Monolithic spacecraft design:
-eliminates rotating assemblies
-eliminates sensor gimballing
-eliminates flex fluid lines, fluid swivel joints
8) No solar array deployment
9) No radiator deployment
10) No center-of-gavity shifts resulting from sensor motion
11) No batteries required for eclipse operation
12) No thermal storage required for refrigerator operation during eclipse

Source: Unique Features and Spacecraft Applications of Dynamic Isotope Power Systems
Website: https://www.osti.gov/servlets/purl/1033342

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CHAN ZE YU
LINGHAN A/L SAMANASEH
NIRRESH PRABU A/L RAVINDRAN
SHARFA ELIYA BT MOHD FADZIL
TEO CHEN LUNG
ZULARIEFF REDZWAN BIN SULAIMAN

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By: CHAN ZE YU
Source: Mukund R. Patel. (2005) Spacecraft Power System. Retrieved on 1 March 2018

Dynamic System in the spacecraft has higher efficiency since its engine has higher efficiency of 20 to 40 % while there are only 12 to 20 % for silicon solar cells. Also, this system has higher efficiency of thermal energy storage of receiver than the normal battery efficiency. These improve the overall system efficiency tremendously :
- reduced drag, thus allowing lower flight altitudes within given constraints of drag-makeup fuel and orbit delay time.
- less concern on station dynamics, approach corridors and experimental viewing angles.

As particularly for solar dynamic power system, it has some other strong points over the other power systems:
- low solar collection area
- high voltage AC power generation
- highly scalable and mass producible
- long life components
- inherent radiation tolerance.

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Solar Power Concentrator in Space - Enigma Group

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Solar Power Concentrator in Space - Enigma Group

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by: TEO CHEN LUNG
Introduction of Solar Power Concentrator.

Concentrating solar power (CSP) plants use mirrors to concentrate the energy from the sun to drive traditional steam turbines or engines that create electricity. The thermal energy concentrated in a CSP plant can be stored and used to produce electricity when it is needed, day or night.

Source: Solar Energy Industries Association (SEIA®)

Website:
https://www.seia.org/initiatives/concentrating-solar-power

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Solar Power Concentrator in Space - Enigma Group

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Solar Power Concentrator in Space - Enigma Group

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by: TEO CHEN LUNG
Introduction of Solar Power system in space.

Source:  NASA Technical Memorandum 107252  Early Results From Solar Dynamic Space Power System Testing

Website: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960047096.pdf

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By : Linghan Samanaseh

Radioisotope Thermoelectric Generators (RTGs) are proven space system power sources. The currently available system, the MMRTG , shown in Fig 2, has a beginning of mission power level of approximately 110 We. It has an annual degradation rate on the order of 4% per year, due to the natural decay of the plutonium heat source and performance degradation of the thermoelectric materials. This results in reduced electrical power output when the spacecraft arrives at its destination, which for an RPS-powered mission can be over a decade after launch. Thus, the power available for science and communication may be limited when it is most needed, which reduces the attractiveness of thermoelectric systems for outer planet exploration.

Dynamic power systems have the potential to produce higher electrical power outputs within the same volume while using less heat source plutonium, and experience very little conversion efficiency degradation because of the virtual elimination of wear mechanisms within the convertor itself. These advantages come with the need to demonstrate sufficient performance, actual degradation rates and reliability, and accommodate the operating characteristics on a spacecraft within the context of a mission.

Website : http://ieeexplore.ieee.org/document/7943892/

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BY:SHARFA ELIYA BT MOHD FADZIL

DEFINITION OF DYNAMIC POWER

Solar dynamic power contributes to power sources to the spacecraft which involves a number of moving parts that requires rather precise solar pointing to work.
- Dynamic power conversion offers the potential to produce Radioisotope Power Systems (RPS) that generate higher power outputs
- Utilize the available heat source plutonium fuel more efficiently than Radioisotope Thermoelectric Generators.
-Offer the potential of producing generators with significantly reduced power degradation over the course of deep space missions

Website :

https://forum.nasaspaceflight.com/index.php?topic=28993.0

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Solar Power Concentrator in Space - Enigma Group

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Solar Power Concentrator in Space - Enigma Group

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by: CHAN ZE YU
Overviews of the solar power system of a space station.

Source: Fundamentals of Space Systems and Space Subsystem

Website: https://www.slideshare.net/aticourses/fundamentals-of-space-systems-space-subsystems-course-sampler

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One of the source of power for spacecraft is from the Dynamic System. Please find all necessary info on this Power source. You should define what is solar power concentrator. How can dynamic system generate power? find an example of spacecraft use that. Everyone in the group should contribute