Compressorless Heat Engines for Efficient Low-Temperature Heat Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Rankine cycle power systems suffer from inefficiencies due to irreversibilities and limited temperature ranges, particularly in organic Rankine cycles (ORCs), which hinder effective energy recovery from low-temperature heat sources.
Innovation Solution
A system and method involving a lubricating oil and refrigerant mixture, where the lubricating oil is atomized and dispersed within the refrigerant, allowing for efficient heat transfer and power generation without a compressor, utilizing a closed-loop path with high-pressure and low-pressure zones and a bypass zone to enhance energy conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional Rankine cycle systems are used, then electricity generation from heat sources is achieved, but efficiency is limited due to irreversibilities and pressure drops
Solution Approach 1:
The patent extracts the compressor component from the conventional Rankine cycle system, creating a compressorless organic Rankine cycle (ORC) system. This elimination removes the irreversibilities and efficiency losses associated with compression, directly addressing the energy loss problem while simplifying the overall system architecture
Solution Approach 2:
The patent introduces a working fluid mixture comprising a base fluid and a secondary component as an intermediary substance. This mixture serves as a heat transfer medium that enables efficient thermal energy transfer from low-temperature sources to the expansion device, improving cycle efficiency without requiring complex high-temperature components
2Power
If high turbine entry temperature is used, then power output increases, but material creep limits restrict temperature to around 565°C
Solution Approach 1:
The patent changes the thermodynamic parameters of the system by using a specialized working fluid mixture with optimized thermal properties. This allows the system to operate efficiently at lower temperatures while maintaining acceptable power output, bypassing the material creep limit constraint through fluid property optimization rather than temperature increase
Solution Approach 2:
The patent employs a composite working fluid system consisting of a base fluid and a secondary component in specific proportions. This composite fluid mixture provides enhanced thermal transfer properties and allows operation at lower temperatures while maintaining system efficiency and power output without being constrained by material temperature limits
3Adaptability or versatility
If organic Rankine cycle is used for low-temperature heat sources, then energy recovery is enabled, but efficiency is reduced compared to conventional systems
Solution Approach 1:
By removing the compressor from the ORC system, the patent eliminates the major source of irreversibilities and efficiency losses. This extraction allows the system to maintain adaptability to low-temperature heat sources while significantly improving cycle efficiency compared to conventional ORC systems
Solution Approach 2:
The patent replaces the mechanical compression process with a direct expansion process using an expansion device. This substitution eliminates the mechanical irreversibilities associated with compression and allows efficient energy recovery from low-temperature heat sources while improving overall cycle efficiency
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 achieves higher power output and efficiency by converting low-temperature heat into electricity with reduced friction losses, surpassing conventional systems by generating electricity from low-temperature heat sources efficiently.
Implementation Method 1
atomizing the lubricating oil to disperse the lubricating oil within the refrigerant
Implementation Method 2
atomizing the lubricating oil to disperse the lubricating oil within the refrigerant
Implementation Method 3
at least a portion of the first portion of the refrigerant is in a gaseous phase
Implementation Method 4
the steam is sent through a turbine... the steam is condensed back into water
Implementation Method 5
thermal energy is used, in a boiler, to turn water into steam
Implementation Method 6
the Rankine cycle generates about 80% of all electric power used throughout the world, and is used by solar thermal, biomass, coal and nuclear power plants
Implementation Method 7
the steam is sent through a turbine... the steam is condensed back into water
Implementation Method 8
the expansion is isentropic (i.e., at constant entropy)
Implementation Method 9
the condensate is pumped back to the boiler
Data Source
AI summary
A method for generating power from a heat source includes mixing a refrigerant in a liquid phase with a lubricating oil, heating the mixture to evaporate the refrigerant, mixing the heated mixture with additional refrigerant in a superheated phase, and atomizing the lubricating oil to disperse the lubricating oil within the refrigerant. The atomized lubricating oil and the refrigerant are passed through a decompressor to generate an electrical current. The refrigerant may be an organic material having a boiling point below about −35 C. Related systems and heat engines are also disclosed.