Open Circuit Refrigeration With Ejector to Reduce Weight and Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional refrigeration systems are heavy and power-intensive, making them impractical for applications with size and weight constraints, such as mobile platforms, and struggle to maintain precise temperature control for high heat flux, temperature-sensitive loads.
Innovation Solution
The implementation of open circuit refrigeration systems with an ejector and liquid separator, which use a mixture of liquid and vapor refrigerant phases to extract heat energy, allowing for efficient cooling with reduced system size, weight, and power consumption, and precise temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional closed circuit refrigeration systems are used, then reliable cooling function is achieved, but system weight and power consumption increase significantly
Solution Approach 1:
The patent extracts and removes the heavy compressor and condenser components from the refrigeration system, transitioning from a closed circuit to an open circuit configuration. This extraction eliminates the need for mechanical compression while maintaining the essential cooling function through natural refrigerant phase changes and direct heat rejection to the environment.
Solution Approach 2:
The patent replaces the mechanical compression system with a thermodynamic-based open cycle system that uses refrigerant phase changes and natural convection for heat rejection. This substitution eliminates mechanical moving parts while achieving the same cooling effect through thermodynamic principles.
2Reliability
If conventional closed circuit refrigeration systems are used, then reliable cooling function is achieved, but power consumption increases significantly
Solution Approach 1:
The patent replaces the energy-intensive mechanical compression system with a passive thermodynamic system that utilizes natural refrigerant evaporation and condensation processes. This substitution eliminates the need for electrical power to drive compressors while maintaining reliable cooling through phase change heat transfer.
Solution Approach 2:
The open circuit system performs self-service by using the refrigerant's own phase changes to provide cooling without external mechanical assistance. The refrigerant naturally evaporates at the evaporator to absorb heat and condenses at the heat rejection exchanger to release heat, eliminating the need for powered compression.
3Duration of action of moving object
If receiver size is increased to extend operation duration, then operating period is extended, but system weight and volume increase
Solution Approach 1:
The patent ensures continuous cooling operation by maintaining a steady flow of refrigerant through the open circuit system. The continuous evaporation and condensation processes provide sustained cooling without requiring large storage capacities, as the system operates continuously as long as refrigerant is available and heat sinks are functional.
Solution Approach 2:
The open circuit system recycles the refrigerant continuously through evaporation and condensation phases, effectively recovering and reusing the same refrigerant mass repeatedly. This continuous recycling eliminates the need for large receiver sizes to extend operating duration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces the overall size, weight, and power consumption of refrigeration systems while maintaining precise temperature control for high heat flux loads, particularly suitable for mobile platforms and temperature-sensitive components.
Implementation Method 1
an ejector having a primary inlet coupled to the receiver, a secondary inlet, and an outlet
Implementation Method 2
use a mixture of liquid and vapor refrigerant phases to extract heat energy
Implementation Method 3
a liquid separator having an inlet and first and second outlets
Implementation Method 4
separate liquid refrigerant from vapor refrigerant
Implementation Method 5
configured to extract heat from a heat load that contacts the evaporator
Implementation Method 6
use a mixture of liquid and vapor refrigerant phases to extract heat energy
Implementation Method 7
a heat rejection exchanger (i.e., a condenser)
Implementation Method 8
discharge thermal energy into the surrounding environment
Data Source
AI summary
A thermal management system is described. The thermal management system includes an open circuit refrigeration circuit that has a refrigerant fluid flow path, with the refrigerant fluid flow path including a receiver configured to store a refrigerant fluid, an ejector having a primary flow inlet configured to receive refrigerant, a liquid separator, an evaporator configured to extract heat from a heat load that contacts the evaporator, with the evaporator coupled to the ejector and the liquid separator, and an exhaust line coupled to a vapor side outlet of the liquid separator. In operation, the evaporator in the open circuit refrigeration circuit would be coupled to a heat load.