Ejector Heat Pump With Fluid Separation for Higher COP
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Solution Overview
Problem
Conventional steam jet cooling systems have low coefficients of performance (COP) and use non-environmentally friendly fluids, with significant efficiency losses due to shock transitions and high global warming potentials.
Innovation Solution
A thermally driven heat pump system using a primary fluid immiscible with the cooling fluid, with a converging/diverging chamber and nozzle apparatus for high-speed vapor injection, and a separator for fluid separation, along with an absorption apparatus to enhance COP and reduce environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional steam jet cooling systems are used, then the system structure is simple, but the coefficient of performance (COP) is low (0.2-0.3)
Solution Approach 1:
The system divides the cooling process into two separate evaporators: a primary fluid evaporator and a cooling fluid evaporator. Each evaporator handles a specific fluid type, allowing optimized heat transfer processes. The primary fluid evaporator uses high-temperature heat source to vaporize primary fluid, while the cooling fluid evaporator operates at lower temperatures, enabling independent optimization of each evaporation process for improved overall COP.
Solution Approach 2:
The patent introduces an intermediary heat exchanger that facilitates heat transfer between the primary fluid vapor and the cooling fluid vapor. This intermediary device allows efficient energy exchange between the two fluid systems, enabling the high-temperature primary fluid to transfer heat to the low-temperature cooling fluid, thereby improving the overall heat transfer efficiency and COP of the system.
2Reliability
If perfluorocarbon is used as the working fluid, then the fluid properties are suitable for ejector operation, but the global warming potential is high
Solution Approach 1:
The patent changes the chemical composition parameters of the working fluids by selecting alternative substances with low global warming potential. Specifically, it uses HFE-7100 (heptafluoropropane) as the primary fluid and water or other environmentally friendly refrigerants as the cooling fluid. These alternatives maintain the necessary physical properties for ejector operation while significantly reducing environmental harm compared to traditional perfluorocarbon substances.
3Temperature
If high pressure is maintained at the ejector exit to achieve high lift ratio, then the cooling capability is improved, but substantial heat energy is required increasing enthalpy change
Solution Approach 1:
The patent utilizes phase transitions of two different fluids occurring at different temperature levels. The primary fluid undergoes phase transition at high temperature in its evaporator, while the cooling fluid undergoes phase transition at lower temperature in its evaporator. This dual phase transition approach allows the system to achieve high cooling capability at the low-temperature evaporator outlet without requiring excessive heat energy input, as the heat is efficiently transferred through the intermediary heat exchanger.
4Device complexity
If abrupt transition from supersonic to subsonic flow is used in the ejector, then the device structure is simple, but large efficiency losses occur due to shock
Solution Approach 1:
The patent introduces a movable diaphragm or adjustable valve in the ejector that dynamically controls the flow transition from supersonic to subsonic regime. This dynamic element allows the system to optimize the expansion process by controlling the timing and location of the shock transition, reducing abrupt pressure changes and minimizing energy losses while maintaining relatively simple ejector structure.
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 a higher COP and reduces global warming potential by using environmentally friendly fluids, minimizing shock losses, and optimizing fluid mixing and separation, leading to improved efficiency and reduced energy consumption.
Implementation Method 1
nozzle apparatus in fluid communication with the primary fluid evaporator to receive primary fluid vapor and to eject the primary fluid vapor into the converging/diverging chamber at high speed
Implementation Method 2
The low temperature evaporator is in fluid communication with the converging/diverging chamber so that cooling fluid vapor from the low temperature evaporator is aspirated into the converging/diverging chamber
Implementation Method 3
A first heat exchanger located at an outlet of the converging/diverging chamber of the ejector can receive a flow of primary fluid vapor and cooling fluid vapor ejected from the ejector for removing heat from the cooling fluid vapor and primary fluid vapor to facilitate condensation
Implementation Method 4
A separator is in fluid communication with the heat exchanger, the low temperature evaporator and the primary fluid evaporator for use in separating the primary fluid liquid from the cooling fluid liquid, so that cooling fluid can be returned to the low temperature evaporator and the primary fluid can be returned to the high temperature evaporator
Implementation Method 5
a low temperature evaporator for evaporating the cooling fluid to remove heat
Implementation Method 6
A primary fluid evaporator can be used for evaporating the primary fluid by application of heat
Data Source
AI summary
A thermally driven heat pump includes a low temperature evaporator for evaporating cooling fluid to remove heat A first heat exchanger located at an outlet of a converging/diverging chamber of a first ejector receives a flow of primary fluid vapor and cooling fluid vapor ejected from the first ejector for condensing a portion of the cooling fluid vapor An absorber located in the first heat exchanger absorbs cooling fluid vapor into an absorbing fluid to reduce the pressure in the first heat exchanger A second heat exchanger located at an outlet of a converging/diverging chamber of a second ejector receives primary fluid vapor and cooling fluid vapor ejected from the second ejector for condensing the cooling fluid vapor and the primary fluid vapor A separator in communication with the second ejector, the low temperature evaporator and the primary fluid evaporator separates the primary fluid from the cooling fluid.