Transformer Cooling Flow Multiplier for Winding Hot-Spot Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transformers experience hot-spot issues due to radial eddy current losses and uneven temperature profiles within transformer tanks, which conventional cooling methods struggle to address effectively.
Innovation Solution
A cooling arrangement utilizing a Coand effect fluid flow multiplier to enhance fluid circulation and entrainment within transformer tanks, where a fluid discharge device with a Coand effect fluid flow multiplier is used to direct cooled fluid along the windings, improving heat dissipation and temperature uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling methods (heat exchangers, radiators) are used to cool the transformer, then the overall temperature is reduced, but hot-spot problems persist in the top parts of the windings due to radial eddy current losses and uneven temperature distribution
Solution Approach 1:
The patent applies local quality by directing cooled fluid specifically to the top parts of the windings where hot-spots occur. The fluid discharge device is positioned to target the problematic areas, and the flow rate is adjusted locally to ensure adequate cooling where radial eddy current losses generate excessive heat, rather than applying uniform cooling throughout.
Solution Approach 2:
The patent implements dynamics by using variable speed pumps and controllable valve arrangements that allow the cooling system to adapt to changing thermal conditions. The flow rate of cooled fluid can be dynamically adjusted based on transformer load and temperature measurements, enabling the system to respond to varying hot-spot conditions in real-time.
2Device complexity
If natural convection is relied upon for fluid circulation, then the system is simple, but the temperature profile becomes uneven with hotter fluid accumulating at the top
Solution Approach 1:
The patent transitions from static natural convection to dynamic forced convection using variable speed pumps. This allows the system to actively control fluid circulation patterns, maintaining simplicity in basic components while adding dynamic control capability to achieve uniform temperature distribution through adjusted flow rates and controllable valve arrangements.
Solution Approach 2:
The patent implements feedback control by monitoring temperature distribution and using this information to adjust pump speed and valve positions. Temperature sensors detect hot-spots and uneven temperature profiles, and the control system responds by modifying fluid flow patterns to eliminate temperature gradients, creating a self-regulating cooling system.
3Loss of energy
If high flow rates are used to cool the windings, then heat dissipation improves, but energy consumption increases
Solution Approach 1:
The patent applies dynamics by using variable speed pumps that adjust flow rate based on actual cooling requirements. During low-load conditions or when windings are already cool, the pump operates at lower speeds, reducing energy consumption. During high-load conditions or when hot-spots develop, the pump increases flow rate to improve heat dissipation efficiency, optimizing the balance between cooling performance and energy use.
Solution Approach 2:
The patent implements parameter changes by varying the flow rate of cooled fluid to match thermal demand. The system monitors temperature conditions and adjusts the flow parameter dynamically, using higher flow rates when heat dissipation is critical and lower flow rates when cooling demand is reduced, thereby minimizing pump energy consumption while maintaining effective heat removal.
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 cooling arrangement effectively reduces winding and hotspot temperatures by optimizing fluid circulation, utilizing the Coand effect to enhance entrainment and inducement of cooled fluid, thereby improving the efficiency of heat transfer and temperature management within the transformer tank.
Implementation Method 1
The fluid discharge device comprises at least one Coand effect fluid flow multiplier configured to discharge the cooled fluid along a discharge axis towards one or more of the windings of the at least one phase leg of the transformer
Implementation Method 2
The at least one heat exchanger is in fluid communication with the transformer tank and configured to receive heated fluid from the transformer tank and to supply cooled fluid to the transformer tank
Implementation Method 3
A pump is in fluid communication with the at least one heat exchanger and with the fluid discharge device and configured to pump cooled fluid from the at least one heat exchanger to the fluid discharge device
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The disclosure relates to a cooling arrangement (1) for cooling a transformer (10) in a transformer tank (12), the cooling arrangement (1) comprises a transformer tank (12), to be at least partially filled with an electrically insulating fluid when in use, a transformer (10) having windings (16), at least one heat exchanger (18), and a fluid discharge device (20) arranged in the transformer tank (12), fluidly connected to the at least one heat exchanger (18), and a pump (22) in fluid communication with the at least one heat exchanger (18) and with the fluid discharge device (20). The fluid discharge device (20) comprises at least one Coand effect fluid flow multiplier (21) configured to discharge the cooled fluid along a discharge axis (c) towards one or more of the windings (16) of the at least one phase leg (14) of the transformer (10).