Sealed Downhole Drive Cooling via Crossflow Heat Exchangers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Downhole electric drive systems for ESPs face challenges in cooling in harsh environments, particularly in locations with sand and dust, where conventional cooling methods are inefficient or prone to maintenance issues, and filtering ambient air is impractical due to fine particulates.
Innovation Solution
A sealed drive system with crossflow-type air-to-air heat exchangers that circulates internal air through one set of passageways while external cooling air flows through another, preventing contaminants from entering the sealed compartments and efficiently transferring heat without the need for constant power input or complex filtration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ambient air is circulated through the drive for cooling, then heat dissipation is achieved, but sand and dust accumulate in the drive reducing cooling efficiency
Solution Approach 1:
The drive is divided into sealed compartments that isolate internal components from external contaminated air, while separate cooling pathways allow heat exchange without contaminant ingress
Solution Approach 2:
A heat exchanger acts as an intermediary between internal drive air and external ambient air, enabling thermal energy transfer while preventing sand and dust particles from entering the sealed compartments
2Reliability
If filters are used to remove sand and dust from ambient air, then contamination is reduced, but airflow is impeded reducing cooling effectiveness
Solution Approach 1:
The heat exchanger serves as a mediator that enables thermal interaction between clean internal air and contaminated external air without requiring direct mixing or filtration of the external air stream
Solution Approach 2:
Separate airflow paths are created: one for internal drive air circulation through components, another for external ambient air intake, with heat exchange occurring between these segregated streams
3Temperature
If thermoelectric cooling systems are used to dissipate heat, then cooling effect is provided, but large amounts of power are consumed
Solution Approach 1:
The system uses the drive's own operational characteristics - specifically the rectified DC bus voltage - to power the cooling fan, making the cooling system self-sufficient without requiring additional external power input
Solution Approach 2:
The cooling fan operates periodically based on thermal conditions, activated when heat dissipation is needed and deactivated when cooling requirements are met, optimizing energy utilization
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 sealed drive system effectively manages heat in contaminated environments, preventing contamination and reducing maintenance needs, while maintaining efficient airflow and heat transfer, thus enhancing the operational longevity and reliability of downhole equipment.
Implementation Method 1
Heat flows from the internal air, through the plates to the external air, which flows out of the duct to remove heat from the drive
Implementation Method 2
External air is forced into the duct where it flows through the heat exchangers
Data Source
AI summary
Systems and methods for cooling a drive for downhole electric equipment such as an ESP, wherein the drive's electrical components are contained in one or more sealed enclosures to protect them from contaminants in external cooling air. In one embodiment, the drive has two sealed compartments that contain electrical components. Air internal to these compartments is circulated through air-to-air heat exchangers that are positioned in an adjacent duct. Alternating horizontal and vertical passageways through the heat exchangers are formed by flat plates that are offset from each other and connected alternately at their top/bottom and side edges. Air external to the sealed compartments is circulated through the duct to cool the heat exchangers. The amount of air circulated through each heat exchanger may be controlled by valves that regulate airflow through one or more outlets from the duct.