Hydropneumatic Accumulator Heat Conversion via Gas Transfer
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Solution Overview
Problem
Existing methods for converting heat into fluid power suffer from low efficiency, slow operation, and reliability issues due to high thermal inertia, inefficient heat utilization, and cyclic heating and cooling of massive heat exchangers, which reduces power density and makes it difficult to accumulate heat during temporary shutdowns.
Innovation Solution
The method involves using at least two hydropneumatic accumulators with separate heat exchangers for heating and cooling, where the gas is transferred between them to maintain higher temperatures during expansion and lower temperatures during compression, utilizing forced convection and regenerative heat exchangers to enhance heating and cooling rates, and employing hydraulic transformers to manage liquid flow and pressure differences, thereby reducing heat losses and increasing thermodynamic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If heat is supplied to gas in a receiver through cyclic heating and cooling of massive heat exchangers, then heat conversion into fluid power is achieved, but thermal inertia increases causing slow operation and reduced power density
Solution Approach 1:
The system divides the thermal management function into separate components: a thermal energy storage tank stores heat independently, while a smaller heat exchanger rapidly transfers heat to the gas. This segmentation eliminates the need for cyclic heating and cooling of large heat exchangers, reducing thermal inertia and increasing operation speed and power density.
Solution Approach 2:
Heat is pre-stored in the thermal energy storage tank before it is needed for power generation. This preliminary action allows the heat exchanger to rapidly transfer pre-heated fluid to the gas without waiting for slow cyclic heating, thereby increasing operation speed and power density while maintaining efficient heat conversion.
2Loss of energy
If cyclic heating and cooling of massive heat exchangers is used, then heat transfer to gas is achieved, but heat utilization efficiency decreases due to heat losses
Solution Approach 1:
The system separates the heat storage function from the heat transfer function. The thermal energy storage tank retains heat without the need for cyclic operation, while the smaller heat exchanger efficiently transfers heat to the gas. This eliminates heat losses associated with cyclic heating and cooling of large components, improving heat utilization efficiency and power output.
Solution Approach 2:
The thermal energy storage tank passively maintains heat through its insulation design, requiring no active heating or cooling. This self-service approach eliminates energy losses from cyclic thermal management while continuously providing heat for power generation, improving both heat utilization efficiency and power output.
3Reliability
If separate heat exchangers are used for heating and cooling, then heat transfer is achieved, but device complexity increases
Solution Approach 1:
The thermal energy storage tank serves multiple functions: it stores thermal energy, acts as a heat source, and provides thermal mass for stable temperature maintenance. This multi-functionality reduces the need for separate specialized components, simplifying the overall system configuration while improving reliability through reduced component count and interconnections.
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 approach significantly increases the efficiency and speed of heat conversion into fluid power, improves power density, and enhances reliability by minimizing heat losses and eliminating cyclic stress on heat exchangers, allowing for heat accumulation during temporary shutdowns or reduced heat supply.
Implementation Method 1
heat supply to the gas and heat removal from the gas performed so that the average gas temperature during expansion is higher than that during compression
Implementation Method 2
utilizing forced convection and regenerative heat exchangers to enhance heating and cooling rates
Implementation Method 3
employing hydraulic transformers to manage liquid flow and pressure differences
Data Source
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AI summary
Method of conversion of heat into fluid power includes pumping of the working liquid into a hydropneumatic accumulator with gas compression, subsequent gas expansion with displacement of the working liquid from the other accumulator as well as supply of heat to the gas by transferring the gas through the hotter heat exchanger and removal of heat from the gas by transferring the gas through another, colder heat exchanger performed so that the average temperature of the gas during expansion is higher than that during compression, wherein the gas is transferred between different accumulators through said heat exchangers. The device for conversion of heat into fluid power includes at least two accumulators, the means for liquid supply and intake as well as the means for heating and cooling containing at least two flow-type gas heat exchangers installed with the possibility of gas transfer through them between gas reservoirs of different accumulators. The efficiency and rate of heat conversion into fluid power are increased. Reliability and high power density are ensured.