Geothermal energy system
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Solution Overview
Problem
Current closed loop geothermal systems recover significantly less energy compared to binary processes due to limitations in heat transfer mechanisms, particularly conduction and natural convection, which are dependent on rock properties and temperature differentials.
Innovation Solution
The integration of a recirculation circuit into a well bore heat exchanger (WBHX) to actively circulate reservoir fluid, enhancing heat transfer by increasing the temperature differential and effective rock volume available for latent heat recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a closed loop well bore heat exchanger system is used to avoid GHG production and mineral deposition, then environmental benefits are achieved, but energy recovery rate decreases by an order of magnitude compared to binary processes
Solution Approach 1:
The patent introduces a dynamic recirculation circuit that actively circulates reservoir fluid through the well bore heat exchanger, transforming the static heat extraction process into a dynamic one. This active circulation enhances heat transfer coefficients and increases the effective heat exchange surface area over time, thereby significantly improving energy recovery rates while maintaining the closed-loop environmental benefits
Solution Approach 2:
The recirculation circuit enables continuous heat extraction from the same reservoir zone by repeatedly circulating fluid through the heat exchanger. This continuous action maximizes the utilization of the thermal energy stored in the reservoir rock, increasing the total energy recovered per unit volume of reservoir compared to single-pass systems
2Device complexity
If conventional conduction and natural convection heat transfer mechanisms are used in closed loop systems, then system simplicity is maintained, but heat transfer rate is limited by rock properties and temperature differentials
Solution Approach 1:
The patent employs hydraulic principles by using a recirculation pump to force reservoir fluid through the well bore heat exchanger at controlled flow rates. This forced circulation creates high-velocity fluid flow that enhances convective heat transfer coefficients, overcoming the limitations of natural convection and conduction while adding only moderate system complexity
Solution Approach 2:
The system changes the flow rate parameter of the reservoir fluid through active recirculation, transforming it from a static or naturally flowing condition to a high-velocity forced circulation state. This parameter change directly increases the convective heat transfer coefficient and the overall heat transfer rate, addressing the productivity limitation
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 increases the rate of heat recovery, potentially by 200% to 1200%, thereby improving the energy recovery efficiency and economic viability of geothermal energy systems.
Implementation Method 1
In closed systems, there are two heat transfer mechanisms that govern energy recovery, conduction and natural convection
Implementation Method 2
In closed systems, there are two heat transfer mechanisms that govern energy recovery, conduction and natural convection
Implementation Method 3
The primary factor governing energy recovery in closed loop systems is the rate of heat transfer from the surrounding rock matrix to the WBHX
Data Source
AI summary
A system for geothermal heating, the system comprising a forced geothermal circuit disposed in a well bore. The system also comprise a well bore heat exchanger and an pump. The system may further comprise a circulation fluid and flux co-inverter. A method for geothermal heating, the method comprising passing a fluid into a thermal circulation system; passing the fluid into a well bore heat exchanger; passing reservoir fluid into an annulus space; and passing the reservoir fluid through a sub-surface formation.