Two-Phase Refrigerant Cooling Circuit for Condensation Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cooling systems for aircraft using two-phase refrigerants face challenges in maintaining reliable operation at low ambient temperatures due to refrigerant condensation in the tubing, leading to potential system failure and the need for overdesigning the cooling circuit and refrigerant quantity.
Innovation Solution
A cooling system with a detection device to monitor refrigerant state and a control device that adjusts temperature and pressure to prevent condensation, ensuring the refrigerant remains in a gaseous state, using a condenser and accumulator with subcooling capabilities, and employing heating devices to maintain the refrigerant in its desired state, thereby preventing accumulation and ensuring continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the tubing is insulated to prevent heat introduction at high ambient temperatures, then heat insulation performance is improved, but at low ambient temperatures the insulation is insufficient to prevent tubing temperature from falling below the dew point, causing refrigerant condensation
Solution Approach 1:
The patent applies dynamic heating control by equipping the tubing with heating devices that are activated only when ambient temperature drops below a predetermined threshold. This dynamic adjustment allows the system to adapt to changing environmental conditions, providing heating only when necessary to prevent condensation, thereby resolving the contradiction between insulation performance and condensation prevention across different temperature conditions.
Solution Approach 2:
The patent changes the temperature parameter of the tubing by introducing heating devices that raise the tubing temperature above the dew point when ambient temperatures are low. This parameter change prevents refrigerant condensation without requiring excessive insulation, thus resolving the contradiction between insulation thickness and condensation prevention.
2Reliability
If the cooling circuit is overdesigned with excess refrigerant quantity to compensate for condensation losses, then system reliability is improved, but system weight and installation volume increase
Solution Approach 1:
The patent implements a feedback control system where a sensor detects the actual refrigerant quantity in the cooling circuit and compares it to a reference value. When condensation is detected or refrigerant quantity drops below the reference level, the controller activates the heating device to prevent further condensation and may control the conveying device to replenish refrigerant. This feedback mechanism maintains reliable operation with minimal refrigerant quantity, avoiding the need for overdesign and excessive system weight.
3Reliability
If heating devices are used to prevent refrigerant condensation, then condensation prevention is improved, but energy consumption increases
Solution Approach 1:
The patent employs periodic or conditional heating action rather than continuous heating. The heating devices are activated only during specific periods when ambient temperature drops below the predetermined threshold or when condensation is detected by the sensor. This periodic action prevents condensation effectively while minimizing energy consumption by avoiding unnecessary heating during favorable temperature conditions.
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
The system maintains reliable operation at low ambient temperatures without overdesigning the circuit or increasing refrigerant quantity, preventing condensation and ensuring continuous refrigerant flow, thus maintaining a lightweight and efficient cooling system.
Implementation Method 1
a detection device (42) is provided which is configured to output a signal indicative of the state of aggregation of the refrigerant in a portion (12a) of the cooling circuit
Implementation Method 2
a control device (46) is provided which is configured to control the temperature and/or the pressure of the refrigerant in the portion (12a) of the cooling circuit
Implementation Method 3
The control device (46) is configured to increase the temperature of the refrigerant in the portion (12a) of the cooling circuit which connects the refrigerant outlet (18a, 18b) to the evaporator to the refrigerant inlet (24a, 24b) of the condenser
Data Source
Figure 1
Figure 2
AI summary
A cooling system (10) which is in particular suitable for use on board an aircraft comprises a cooling circuit (12) allowing circulation of a two-phase refrigerant therethrough. An evaporator (14a, 14b) is disposed in the cooling circuit (12) and has a refrigerant inlet (16a, 16b) and a refrigerant outlet (18a, 18b). Further, a condenser (22a, 22b) is disposed in the cooling circuit (12) and has a refrigerant inlet (24a, 24b) and a refrigerant outlet (26a, 26b). A detection device (42) is configured to output a signal indicative of the state of aggregation of the refrigerant in a portion (12a) of the cooling circuit (12) which connects the refrigerant outlet (18a, 18b) of the evaporator (14a, 14b) to the refrigerant inlet (24a, 24b) of the condenser (22a, 22b). A control device (46) is configured to control the temperature and/or the pressure of the refrigerant in said portion (12a) of the cooling circuit (12) in dependence on the signal output by the detection device (42) such that the refrigerant in said portion (12a) of the cooling circuit (12) is maintained in its gaseous state of aggregation.