Cryocoolers with electronic cryostat flow controllers and related system and method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cryocoolers used in focal plane arrays for missiles are inefficient in coolant gas usage, unstable in temperature control, prone to clogging, and have slow and imprecise shape memory metal actuators, which can disrupt the operation of critical missile systems.
Innovation Solution
The implementation of a cryocooler with an electronic cryostat flow controller that includes a heat exchanger, a needle to control coolant gas flow, a motion rod, and an actuator assembly to precisely move the needle, allowing for accurate temperature control using temperature sensors and actuators such as piezoelectric or DC motors to manage the coolant gas flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If variable-flow Joule-Thomson cryostats are used to cool focal plane arrays, then cooling capability is provided, but temperature control stability deteriorates and coolant gas efficiency worsens
Solution Approach 1:
The patent replaces the mechanical variable-flow control system with an electronic control system that uses a solenoid valve and microcontroller to precisely regulate coolant gas flow. This electronic substitution eliminates the instability and inefficiency of mechanical variable-flow Joule-Thomson cryostats while maintaining the cooling function.
Solution Approach 2:
The patent changes the flow control parameter from variable flow to precisely regulated flow using electronic timing and solenoid valve control. By controlling the duration and timing of coolant gas release through programmable logic, the system achieves stable temperature control and improved coolant efficiency.
2Reliability
If variable-flow Joule-Thomson cryostats are used, then cooling function is achieved, but reliability deteriorates due to clogging
Solution Approach 1:
The patent extracts the flow control function from the main cryostat body into a separate electronic control system with a solenoid valve. This separation allows the main coolant passage to remain simple and clog-resistant, while the control mechanism handles flow regulation externally, reducing clogging risks in the critical cooling path.
3Manufacturing precision
If shape memory metal actuators are used in Joule-Thomson cryostats, then flow control is provided, but precision and speed deteriorate
Solution Approach 1:
The patent replaces shape memory metal actuators with an electronic solenoid valve actuation system. The solenoid valve provides rapid electromagnetic actuation with precise control through electronic timing signals, eliminating the slow and imprecise mechanical deformation of shape memory metals while achieving both high speed and high precision flow control.
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 solution provides precise temperature control, reduces coolant gas consumption, enhances system reliability, and prevents clogging, ensuring stable operation even under stressful conditions like rocket separation.
Implementation Method 1
Variable-flow Joule-Thomson cryostats are often used to cool very large focal plane arrays in these types of applications
Implementation Method 2
actuators such as piezoelectric or DC motors to manage the coolant gas flow
Data Source
AI summary
A system includes a cryocooler configured to cool an object, a sensor configured to measure a temperature of the object, and a controller configured to generate an actuator drive signal to control the cryocooler based on at least one temperature measurement from the sensor. The cryocooler includes a heat exchanger and a needle configured to control flow of coolant gas through the heat exchanger. The cryocooler also includes a motion rod configured to move the needle and an actuator assembly configured to move the motion rod to thereby move the needle. The actuator could include a motor and a gear head configured to rotate a lead screw and a lead screw nut located around the lead screw and configured to translate rotational motion of the lead screw into linear motion. The actuator could also include a piezoelectric actuator or a linear actuator.