Method and device for generation of electric power and cold using low-potential heat sources
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Solution Overview
Problem
Existing methods for producing mechanical and electric energy from low-potential thermal sources, such as the Organic Rankine Cycle and Kalina cycle, suffer from low efficiency and the inability to generate cold, with waste heat being released into the environment.
Innovation Solution
A method involving the circulation of a refrigerant and absorbent solution, where the high concentration solution is heated and cooled periodically, with evaporation forming steam and a weak solution, which expands in a turbine and is then absorbed by the weak solution to form a strong solution, utilizing semipermeable membranes, electro dialysis, and the potential energy of the weak solution to enhance efficiency, and employing ionic liquids as working fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the Organic Rankine Cycle or Kalina cycle is used to produce mechanical and electrical energy from low-potential thermal sources, then energy conversion is achieved, but the efficiency of electric energy production is comparatively low and cold cannot be produced
Solution Approach 1:
The absorption cycle system is designed to simultaneously produce both cold (through the evaporator) and electrical energy (through the turbine), making the system multi-functional. The working fluid circulation system serves dual purposes: cooling through evaporation and power generation through expansion in the turbine, eliminating the need for separate systems.
Solution Approach 2:
The system utilizes parameter changes of the working fluid (temperature, pressure, concentration) to achieve both cooling and power generation. By controlling the evaporation temperature for cold production and the expansion pressure for turbine work, the system optimizes both functions simultaneously, improving overall efficiency.
2Power
If the steam expands in the turbine to temperatures higher than the environment temperature level, then work is done, but the exhaust steam cannot be used for cooling external facilities
Solution Approach 1:
The system dynamically adjusts the expansion parameters of the steam in the turbine to achieve optimal balance between power output and exhaust temperature. By controlling the expansion ratio and inlet conditions, the exhaust steam temperature is optimized to be suitable for cooling external facilities, enabling dual utilization.
Solution Approach 2:
The system ensures continuous useful action by utilizing the exhaust steam for cooling external facilities in a continuous process. The absorbed steam is then condensed and fed back into the cycle, maintaining continuous operation of both power generation and cooling functions without interruption.
3Adaptability or versatility
If the steam expands to temperatures lower than the environment temperature level, then the exhaust steam can cool external facilities, but the temperature is too low for efficient turbine work
Solution Approach 1:
The system dynamically controls the expansion process to achieve the optimal balance between turbine work output and exhaust steam temperature for cooling. By adjusting expansion parameters, the system ensures the exhaust temperature is sufficiently high for efficient turbine operation while still being low enough to provide effective cooling to external facilities.
4Device complexity
If a single-component working fluid is used with constant boiling and condensation temperatures, then the cycle is simple, but the thermal energy released during condensation must be evacuated into the environment as waste heat
Solution Approach 1:
The system converts the previously wasted condensation heat into a useful resource for cooling external facilities. The heat that would have been evacuated to the environment is now utilized for productive cooling purposes, transforming a harmful waste stream into a beneficial resource and improving overall energy efficiency.
Solution Approach 2:
The condensation process serves dual functions: maintaining the pressure and temperature conditions needed for the cycle operation and providing useful cooling to external facilities. This multi-functionality eliminates the need for separate waste heat evacuation systems and improves overall system 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
This approach significantly improves the efficiency of electric power and cold generation, exceeding current Carnot cycle efficiencies by utilizing non-equilibrium thermodynamic principles and optimizing the concentration and pressure of the solution through various separation methods and energy utilization.
Implementation Method 1
the strong solution representing, as a rule, the ammonia-water mixture evaporates during the heating at an elevated temperature and an elevated pressure, separating therewith into a steam flow with an increased refrigerant content and a flow of a weak solution with a reduced cooling content of the refrigerant
Implementation Method 2
absorption of the exhaust steam by the weak solution under cooling with the formation of the strong solution
Implementation Method 3
expansion of the refrigerant steam flow in the turbine formed during evaporation with the formation at the turbine exit of the exhaust steam of reduced temperature and pressure
Implementation Method 4
separation of the strong solution into the flows with various concentration using a semipermeable membrane
Implementation Method 5
separation of the strong solution into the flows with various concentration using electro dialysis and shock electro dialysis
Implementation Method 6
utilization of potential energy of the weak solution in the ejector in order to increase the pressure of the cooling agent during absorption
Implementation Method 7
heating of the high refrigerant concentration solution before its evaporation by the weak solution formed during evaporation
Data Source
AI summary
A method for generating electricity and cold and a device for realizing same, consists in a closed absorption cycle in which a working body is a mixture of a low-boiling (refrigerant) component and a high-boiling (absorbent) component. The method involves evaporating a strong solution in a steam generator, thus forming a refrigerant vapor and a weak solution, expanding the refrigerant vapor in a turbine, thus producing work, and, after the turbine, absorbing spent vapor in an absorber, forming a strong solution. A distinguishing feature of the method consists in changing the concentration of a strong solution using two stages, including not only evaporation but also filtration. The proposed method and device allow for significantly increasing the efficiency of systems for generating electricity relative to analogous known methods.