Thermal Energy Conversion System for UUV Periodic Charging
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Solution Overview
Problem
Unmanned underwater vehicles (UUVs) face challenges in prolonged operation due to limited power supply methods, such as tethering, small power generation from expanding wax, and space requirements for fuel cells, which restrict their range and autonomous operation.
Innovation Solution
A thermal energy conversion system using multiple tanks with liquid refrigerant under pressure and insulated water jackets to generate electrical power through temperature differences, with valves controlling the flow of refrigerant and water to optimize power generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If tethering is used to supply power to UUV, then power supply is simplified, but UUV's range and autonomous operation are limited
Solution Approach 1:
The patent replaces the mechanical tether connection with a thermal energy conversion system that uses temperature differences between warm and cold water to drive a refrigerant cycle, generating electrical power independently for the UUV without requiring physical connection to a central power plant
Solution Approach 2:
The system utilizes phase transitions of the refrigerant (evaporation and condensation) driven by temperature differences to convert thermal energy into mechanical work, which then generates electrical power through a generator, enabling autonomous power production for the UUV
2Adaptability or versatility
If expanding wax is used to generate power, then UUV can operate independently, but power generation is limited to less than 200 Watts
Solution Approach 1:
The patent changes the operating parameters by using a refrigerant cycle with controlled evaporation and condensation phases, allowing the system to optimize power generation by adjusting refrigerant flow rates, temperature differentials, and heat exchange efficiency to produce greater than 200 Watts
Solution Approach 2:
The system introduces a refrigerant as an intermediary substance that transfers thermal energy from the warm water source to the cold water sink, enabling efficient heat transfer and power generation that exceeds the capabilities of direct expanding wax systems
3Power
If fuel cells are used to generate power, then adequate power can be supplied, but large packages and substantial space are required
Solution Approach 1:
The patent replaces the chemical fuel cell system with a thermal energy conversion system that uses temperature differences to drive a refrigerant cycle and generator, achieving adequate power supply with a more compact configuration suitable for UUV applications
Solution Approach 2:
The system uses a liquid refrigerant cycle with pumps and valves to control refrigerant flow through evaporation and condensation processes, enabling compact power generation by utilizing fluid dynamics and pressure differentials rather than bulky chemical reactions
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 system enables periodic charging of UUVs, providing a reliable and efficient power source for extended operations by harnessing thermal energy from temperature variations in water, potentially generating more than 250 kJ of energy at a capacity of 37-92 Watt-hours.
Implementation Method 1
one or more insulated water jackets each configured to receive and retain water around at least part of an associated one of the tanks
Implementation Method 2
at least one generator configured to receive a flow of the liquid refrigerant and to generate electrical power based on the flow of the liquid refrigerant
Implementation Method 3
one or more insulated water jackets each configured to receive and retain water around at least part of an associated one of the tanks
Data Source
AI summary
An apparatus includes multiple tanks each configured to receive and store a liquid refrigerant under pressure. The apparatus also includes one or more insulated water jackets each configured to receive and retain water around at least part of an associated one of the tanks. The apparatus further includes at least one generator configured to receive a flow of the liquid refrigerant and to generate electrical power based on the flow of the liquid refrigerant. The apparatus also includes one or more first valves configured to control the flow of the liquid refrigerant between the tanks and through the at least one generator. In addition, the apparatus includes one or more second valves configured to control a flow of the water into and out of the one or more insulated water jackets.