Description
On Delegation Request (formerly called Priority 2)
Objective: The objective is to develop, design and test a thermal expansionvalve for Heat Pump systems or Refrigeration Systems - used as a cooling solution for High Power Telecommunication Satellite.
Targeted Improvements: The targeted improvements will enable development of very high power (over 20 kW) telecommunication payloads by:
- Ensuring continuous flow of the working fluid to the evaporator, ruggedness and reliability.
- Ensuring compatibility with workingfluid.
Description: Heat Pump systems or Refrigeration System are being investigated as a cooling solution for high power dissipation spacecraft. Heat Pump systems allow operating the spacecraft radiators at a higher temperature compared to the internal temperature,which increases the heat rejection capability of the spacecraft without the need of increasing the radiator surface area. In addition, since the radiators are operating at a higher temperature, all external surfaces of the spacecraft can be used to reject heatregardless of the solar loading onto the radiators.
The thermal expansion valve controls the flow of the working fluid to the evaporator and is a key component in the functionality and performance of the heat pump system. As telecommunication payloads increase inpower, the flow rate must also increase and cover a broader range.
There currently does not exist a valve, which is needed for highpower applications. Commercial ground products are available but they may not meet desired performance requirements. Further, the valve mustbe compatible with the intended working fluid, be sufficiently rugged and have the desired reliability for space applications. Hence, a development for a space product is required. A scaled engineering model of a heat pump thermal expansion valve shall be designed, manufactured and tested in a relevant environment to demonstrate its performance.
On Delegation Request (formerly called Priority 2) activities will only be initiated on the explicit request of at least one National Delegation.