Heat Engine Thermal Efficiency Near CO2 Critical Point
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat engines with small temperature differences face inefficiencies due to the changeability of heat capacity in working fluids, which deviates from ideal gas assumptions, leading to lower thermal efficiency compared to Carnot efficiency.
Innovation Solution
The process exploits the variable heat capacity of real gases, particularly carbon dioxide, by using heat exchangers and insulation to minimize waste heat, optimizing heat transfer and pressure changes within the working fluid, thereby enhancing thermal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If heat engines operate with small temperature differences using ideal gas assumptions, then the theoretical efficiency follows Carnot efficiency, but real gas behavior causes significant deviation and reduces thermal efficiency
Solution Approach 1:
The patent changes the operating parameters by operating near the critical point of carbon dioxide, where the fluid exhibits unique thermodynamic properties. By utilizing the region where isobaric heat capacity is much higher than isochoric heat capacity, the system achieves superior thermal efficiency despite small temperature differences, resolving the contradiction between real gas behavior and ideal gas assumptions
Solution Approach 2:
The patent exploits the phase transition region near the critical point of carbon dioxide. By operating in this transitional region where the fluid properties change dramatically, the system can achieve high thermal efficiency through the unique heat capacity characteristics, transforming the harmful real gas deviation into a beneficial feature
2Power
If high temperatures are used to increase power output, then more work can be extracted, but heat released to the environment increases and thermal efficiency decreases
Solution Approach 1:
Instead of using high temperatures, the patent changes the thermodynamic parameters by operating near the critical point of carbon dioxide at moderate temperatures. The unique heat capacity ratio in this region allows efficient work extraction without excessive heat rejection, resolving the contradiction between power output and thermal efficiency
3Use of energy by moving object
If the heat capacity of the working fluid is high during heat addition and removal, then more energy can be transferred, but thermal efficiency decreases due to increased heat loss
Solution Approach 1:
The patent applies local quality by having different heat capacities at different stages of the cycle. The working fluid is designed to have high isobaric heat capacity during heat addition and high isochoric heat capacity during heat removal, optimizing energy transfer while minimizing losses at each stage through targeted heat capacity management
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 results in significantly higher thermal efficiency and working capacity by managing heat capacity variations, even with small temperature differences, as demonstrated with carbon dioxide and other gases in specific temperature ranges.
Implementation Method 1
The heat exchanger 7 transfers heat to the working fluid 4, and the pressure of the working fluid increases
Implementation Method 2
heat engines that convert thermal energy into mechanical energy
Implementation Method 3
The hot zone 8 is partially insulated
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for converting thermal energy into mechanical energy by means of a heat engine using minimal temperature differences, wherein a targeted adjustment of the heat capacity of the working fluid used is carried out by utilizing a material-specific supercritical temperature range in which the working fluid performs a particularly high volume work and converts the supplied heat into mechanical energy via a rotary motion, which is used, for example, to operate generators for the production of electrical energy.