Reversible Heat Pump Cycle Enhancement for Bidirectional CO2 Flow
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Solution Overview
Problem
Conventional heat pumps using carbon dioxide as a refrigerant face inefficiencies in transcritical cycles, limiting its adoption for building air conditioning and heating due to one-way cycle enhancements that do not function optimally in reverse refrigerant flow directions.
Innovation Solution
A cycle enhancement apparatus with one-way valves in a refrigerant line configuration allows for efficient operation in both heating and cooling modes by ensuring the cycle enhancement line functions regardless of refrigerant flow direction, incorporating counterflow heat exchangers or other one-way enhancements like thermoelectric sub-coolers, injection lines, and multi-effect flash tanks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If one-way cycle enhancements are used in a reversible heat pump, then energy efficiency is improved in one direction of refrigerant flow, but the cycle enhancement operates less efficiently or not at all in the reverse direction
Solution Approach 1:
The heat pump system is segmented into multiple refrigerant flow paths with dedicated one-way cycle enhancements for each direction. The refrigerant line is divided into first and second sides, each with its own cycle enhancement apparatus and one-way valves, allowing independent optimization for heating and cooling modes.
Solution Approach 2:
The cycle enhancement apparatus is designed with multi-functionality to serve both heating and cooling modes. By incorporating separate one-way cycle enhancements for each flow direction and using reversing valves to switch between modes, the system achieves universal applicability across both operational directions.
2Ease of manufacture
If carbon dioxide is used as a refrigerant in transcritical cycles, then desirable qualities such as low cost and non-flammability are achieved, but energy efficiency deteriorates
Solution Approach 1:
One-way cycle enhancements act as intermediary devices that mediate between the carbon dioxide refrigerant and the heat exchangers. These enhancements include counterflow heat exchangers, thermoelectric sub-coolers, injection lines, and multi-effect flash tanks that improve the thermodynamic performance of CO2 in both subcritical and transcritical modes.
Solution Approach 2:
The system dynamically changes operating parameters including refrigerant pressure, temperature, and flow rate to optimize energy efficiency. The controlling device adjusts these parameters based on whether the system operates in subcritical or transcritical mode, maximizing the benefits of CO2 as a refrigerant.
3Adaptability or versatility
If a reversing valve is used to change between heating and air conditioning modes, then versatility is improved, but the one-way cycle enhancements may impede operation in reverse mode
Solution Approach 1:
The system dynamically switches between different refrigerant flow configurations using reversing valves. The one-way valves and reversing valves work together to dynamically reconfigure the refrigerant paths, ensuring that the appropriate cycle enhancements are activated for each operational mode without impeding reverse mode operation.
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 configuration enables heat pumps to fully benefit from cycle enhancements in both heating and cooling modes, improving energy efficiency and making carbon dioxide a viable refrigerant for building air conditioning and heating applications.
Implementation Method 1
The first side entrance line has a one-way valve preventing flow toward the first side of the refrigerant line. The first side exit line has a one-way valve preventing flow away from the first side of the refrigerant line.
Implementation Method 2
incorporating counterflow heat exchangers or other one-way enhancements like thermoelectric sub-coolers, injection lines, and multi-effect flash tanks
Implementation Method 3
incorporating counterflow heat exchangers or other one-way enhancements like thermoelectric sub-coolers
Implementation Method 4
incorporating counterflow heat exchangers or other one-way enhancements like thermoelectric sub-coolers, injection lines
Implementation Method 5
incorporating counterflow heat exchangers or other one-way enhancements like thermoelectric sub-coolers, injection lines, and multi-effect flash tanks
Data Source
AI summary
A cycle enhancement apparatus is provided. The apparatus has a first side entrance line and exit line, both connected to a first side of a refrigerant line, and a second side entrance line and exit line, both connected to a second side of the refrigerant line. One-way valves prevent flow through the first side entrance line toward the first side, through the first side exit line away from the first side, through the second side entrance line toward the second side, and through the second side exit line away from the second side. The apparatus has a cycle enhancement line. The cycle enhancement line has an entrance portion, connected to the first side entrance line and the second side entrance line, an exit portion, connected to the first side exit line and the second side exit line, and a cycle enhancement between the entrance portion and the exit portion.