Electrocrushing Drill Pulsed Power System
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Solution Overview
Problem
Existing drilling methods, such as mechanical drilling and electrohydraulic drilling, are inefficient in breaking rock as they apply force in compression, where rock is strongest, whereas electrocrushing methods fail rock in tension, where it is weaker, necessitating a portable drill bit that improves energy transfer into the substrate and overcomes conduction channel impedance.
Innovation Solution
A portable electrocrushing drill system with a bottom-hole assembly featuring a command charge switch to control power delivery to a pulsed power system, including capacitors and a drill pipe with embedded conductors for efficient power transmission, utilizing high-voltage pulses to create arcs that fracture rock without mechanical rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical drilling or electrohydraulic drilling is used, then the drilling process can be performed with simple equipment, but the rock fracturing efficiency is low because these methods apply force in compression where rock is strongest
Solution Approach 1:
The patent replaces mechanical drilling systems with an electrocrushing system that uses high-voltage electrical pulses to create plasma channels through the rock. Instead of mechanical compression or hydraulic pressure, the system applies electrical fields to fail the rock in tension, achieving higher fracturing efficiency while eliminating rotating drill bits and mechanical cutting components.
Solution Approach 2:
The patent changes the fundamental parameter of rock failure from compressive stress to tensile stress by applying high-voltage electrical pulses. This parameter change allows the rock to fail along its weakest point (tension) rather than its strongest point (compression), dramatically improving fracturing efficiency. The system uses pulsed power technology to generate electric fields exceeding the dielectric strength of the rock.
2Use of energy by moving object
If high-voltage pulses are applied to create arcs in rock, then energy transfer into the substrate is improved, but conduction channel impedance creates resistance to efficient power delivery
Solution Approach 1:
The patent uses repetitive pulsed power delivery to overcome conduction channel impedance. By applying a series of high-voltage pulses rather than a continuous signal, the system allows the plasma channel to form and dissipate repeatedly, progressively reducing impedance and improving energy transfer efficiency. The pulsed nature of the power delivery prevents energy loss while building up a stable conduction path.
Solution Approach 2:
The patent maintains continuous useful action by keeping the pulsed power system actively engaged with the rock substrate throughout the drilling process. The repetitive pulses ensure that the plasma channel remains active and the rock continues to fracture along the intended path, maximizing energy transfer efficiency while minimizing losses to impedance by maintaining a stable conduction environment.
3Adaptability or versatility
If a portable drill bit is used to improve adaptability in underground mining, then the system can operate in remote locations, but power delivery to the down-hole pulsed power system becomes challenging
Solution Approach 1:
The patent segments the power delivery system into modular components: a surface-based pulsed power generator, a flexible cable for power transmission, and a down-hole bottom hole assembly containing the electrodes. This segmentation allows the heavy power generation equipment to remain on the surface where it can be supported, while only the lightweight electrode assembly needs to be deployed down-hole, improving portability without sacrificing power delivery capability.
Solution Approach 2:
The patent uses a flexible cable as an intermediary to bridge the power delivery gap between the surface generator and the down-hole electrodes. This cable intermediary transmits high-voltage pulses through the drill string or conduit, enabling power delivery to remote down-hole locations while maintaining the portability and adaptability of the overall system for underground mining applications.
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 higher rock fracturing efficiency by applying electrical energy efficiently, reducing drilling time and cost, particularly in underground hard-rock mining, and allows for precise directional drilling and improved energy transfer into the substrate.
Implementation Method 1
an electric spark, or plasma, within a substrate to fracture the substrate
Implementation Method 2
At sufficiently high electric field, an arc or plasma is formed inside rock from the high voltage electrode to the low voltage or ground electrode
Implementation Method 3
at least one capacitor disposed near the drill bit. The prime power system preferably produces a medium voltage DC power to charge at least one prime power system capacitor
Implementation Method 4
a drill pipe with embedded conductors for efficient power transmission
Implementation Method 5
The prime power system preferably dampens cable oscillations
Data Source
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AI summary
Methods and apparatuses for directly charging capacitors in a down-hole pulsed power system used for electrocrushing drilling. An above ground power supply is directly connected to the capacitors. The power supply can be a switching power supply, a DC supply, or an AC supply. Capacitor voltage is monitored and controlled. The system reduces noise caused by coupling control signal cables and the power cable, and does not have the ground swing control problems of other charging schemes. The power may alternatively be provided by microwave transmission.