Two-Phase Compressor Cycle for High-Temperature Heat Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat recovery and upgrading methods in industrial heat pump systems are limited by low condensation temperatures, typically not exceeding 100°C, which restricts the ability to achieve high-temperature heat recovery and reuse.
Innovation Solution
A method involving a working fluid with a predominantly liquid phase, partial evaporation, compression to increase temperature and pressure, and subsequent condensation, utilizing a binary working fluid like water and ammonia to achieve high-temperature heat recovery, with the working fluid provided as droplets or spray to enhance evaporation efficiency and maintain a wet gas-phase for efficient heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heat is transferred to a working fluid in liquid phase to evaporate it and then compressed, then the temperature and pressure of the fluid rise, but the condensation temperature is limited to about maximum 100°C
Solution Approach 1:
The patent changes the physical parameters of the working fluid by using a two-phase mixture (liquid and vapor) instead of single-phase liquid. This allows the fluid to undergo phase change during compression, enabling condensation temperatures to exceed 100°C while maintaining efficient heat transfer coefficients associated with two-phase flow.
Solution Approach 2:
The invention utilizes phase transitions of the working fluid during compression. By introducing liquid phase into the compressor along with vapor phase, the liquid evaporates during compression absorbing heat, and the resulting two-phase stream can be condensed at higher temperatures, enabling heat recovery above 100°C.
2Device complexity
If only gas-phase working fluid is compressed, then the process is simple, but it causes superheating of the gas phase which drastically lowers the efficiency of the process
Solution Approach 1:
The patent uses a composite working fluid stream consisting of both liquid phase and vapor phase of the working fluid. This two-phase composite mixture is compressed together, allowing the liquid to evaporate during compression and prevent superheating, thereby maintaining high process efficiency while managing the complexity through integrated phase management.
Solution Approach 2:
The liquid phase acts as an intermediary substance during compression. When liquid droplets are introduced into the vapor phase stream during compression, the liquid evaporates and absorbs heat, acting as a thermal mediator that prevents excessive superheating and maintains efficient heat transfer conditions.
3Temperature
If two-phase working fluid is compressed to achieve high condensation temperature, then heat recovery above 100°C is enabled, but the system complexity increases
Solution Approach 1:
The patent segments the working fluid into distinct liquid and vapor phases that are compressed together. By controlling the phase distribution and using separate injection points for liquid into the compression stream, the system manages complexity through phased introduction of liquid droplets rather than requiring complete phase separation equipment.
Solution Approach 2:
The system dynamically manages the two-phase mixture during compression, allowing the liquid phase to evaporate progressively as the gas is compressed. This dynamic phase change process enables high temperature heat recovery while the system adapts to varying operating conditions through controlled phase ratios.
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 allows for efficient heat recovery and upgrading to temperatures above 150°C, enabling the reuse of industrial waste heat streams, improving energy efficiency by maintaining a desired condensation regime and pressure, thus overcoming the limitations of existing systems.
Implementation Method 1
transferring heat to the working fluid stream such as to partially evaporate working fluid in liquid phase to obtain a two-phase working fluid stream in liquid phase and gas phase
Implementation Method 2
compressing the two-phase working fluid stream so as to increase a temperature and pressure of the working fluid and to evaporate working fluid in liquid phase
Implementation Method 3
transferring heat from the working fluid stream by means of condensation of working fluid
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A heat recovery and upgrading method comprises cycles of the subsequent steps of providing a working fluid comprising a liquid phase in a working fluid stream (11); transferring heat (20) to the working fluid stream such as to partially evaporate working fluid in liquid phase to obtain a two-phase working fluid stream (12) in liquid phase and gas phase; compressing (30) the two-phase working fluid stream so as to increase a temperature and pressure of the working fluid and to evaporate working fluid in liquid phase; and transferring heat (40,60) from the working fluid stream (13,14,15) by means of condensation of working fluid. In the first step he working fluid is preferably in a predominantly single-phase working fluid stream in liquid phase when heat is transferred to the working fluid. In the third step working fluid in liquid phase is preferably evaporated so that a two-phase working fluid stream is maintained, especially a wet gas- phase working fluid.