Rotary Gas Heat Engine With Isothermal–Isobaric Segmentation
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Solution Overview
Problem
Existing gas heat engines with external heat supply operate in markedly imperfect cycles, leading to low practical efficiency due to the imperfection of the cycle and imperfect execution of processes.
Innovation Solution
A gas heat engine designed to operate in a continuous closed thermodynamic cycle comprising two isothermal and two isobaric processes, ensuring precise execution of these processes, with a configuration that allows two complete cycles per rotation, utilizing hydrostatic rotary machines with two work segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a Stirling engine operates in a closed thermodynamic cycle, then it can convert heat to mechanical work continuously, but the practical efficiency remains very low due to the imperfect cycle execution
Solution Approach 1:
The thermodynamic cycle is segmented into four distinct processes (isobaric expansion, isothermal expansion, isobaric compression, isothermal compression) with dedicated engines for each process. This segmentation allows each process to be optimized independently, with isobaric processes in one engine and isothermal processes in another engine, improving overall cycle execution perfection and reducing energy losses.
Solution Approach 2:
A recuperator is introduced as an intermediary device between the expansion and compression engines. It recovers heat from the high-temperature gas exiting the expansion engine and transfers it to the low-temperature gas entering the compression engine, significantly reducing the heat input required and improving practical efficiency by minimizing energy losses.
2Manufacturing precision
If the working volume in the isobaric engine is made larger than in the isobaric compressor, then the isobaric process can be executed more precisely under constant pressure, but the device complexity increases
Solution Approach 1:
The system uses separate isobaric expansion engine and isobaric compression engine with independently optimized working volumes. The expansion engine has a larger working volume to ensure precise isobaric expansion, while the compression engine has a smaller working volume suitable for compression, allowing each to operate at optimal precision without compromising the other.
Solution Approach 2:
Multiple engines (isobaric expansion, isothermal expansion, isobaric compression, isothermal compression) are merged into a single integrated system connected by a common shaft and coupled through a recuperator. This merging allows the system to achieve precise process execution through individual engine optimization while maintaining overall system compactness and reducing net device complexity.
3Productivity
If two complete cycles occur during one rotation, then the output performance increases, but the device complexity increases due to multiple work segments
Solution Approach 1:
The system employs periodic action by designing hydrostatic rotary machines with two work segments that complete two full thermodynamic cycles during one rotation. Each half-rotation executes one complete cycle, doubling the output performance. The periodic arrangement of work segments around the rotary mechanism enables this high-frequency cycling while maintaining mechanical simplicity through continuous rotational motion.
Solution Approach 2:
The hydrostatic rotary machines are designed with multi-functionality, where a single rotating component performs both expansion and compression functions through different work segments. The same rotary mechanism handles multiple thermodynamic processes (isobaric expansion, isothermal expansion, isobaric compression, isothermal compression) in sequence, reducing the need for separate dedicated machines and thereby reducing overall device complexity despite the doubled productivity.
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 engine achieves a theoretical efficiency comparable to the Carnot cycle, with usable work output from the shaft, and has a simpler design that can replace combustion engines, offering improved practical efficiency and reduced waste gases.
Implementation Method 1
the temperature of the working gas is increased from T to T1 in the recuperator
Implementation Method 2
the working gas expands isothermally, i.e. under constant temperature its pressure falls from p1 to p, and positive +Wizotherm isothermal work is performed
Implementation Method 3
the working gas is compressed isothermally into the isobaric compressor under high pressure p1
Implementation Method 4
heat Q1 at higher temperature T1 is supplied to the engine. During the engine's activity, heat Q1 at higher temperature T1 is supplied to the engine
Implementation Method 5
a heat-removing substance flows through openings A, B, a constant temperature T is maintained and heat Q is removed during the engine's activity
Implementation Method 6
through a regulator valve, where basically all the actual isobaric processes take place
Data Source
Figure 1
Figure 2
AI summary
The gas heat engine comprises an isobaric compressor (1), which is connected to the shaft of an isothermal compressor (2), and both compressors (1) and (2) are housed in a container (10). The shaft of the isothermal compressor (2) is connected on the other side through a thermal insulation coupling (8) to the shaft of a rotary isothermal engine (4) and a rotary isobaric engine (3), where both engines are housed in a container (10). The output from the isobaric compressor (1) in the container (10) is connected through a recuperator (7) and a regulator valve (6) to the isobaric engine (3) in a container (9), the output from which is connected to the input to the isothermal engine (4) in the container (9), and its output is connected via piping to the recuperator (7), with an input to the isothermal compressor (2) in the container (10), where its output is connected through a check valve (5) to the isobaric compressor (1) in the container (10).