Generator Set Oil Pan Heating With Circulation Against Stratification

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Solution Overview

Problem

Existing oil heating systems in generator sets face issues with large temperature differentials leading to stratified thermal layers and coking or oil oxidation due to inadequate oil flow around heating elements, which hinder the warming of colder oil in the oil pan.

Innovation Solution

A system comprising an oil pan with immersion heaters, a pump, and a return line with apertures that circulates oil to ensure balanced heating, using low watt density heating elements and a pump to distribute oil effectively, allowing for efficient pre-heating of oil while maintaining access for maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If immersion heaters are used in the oil pan, then oil heating capability is improved, but large temperature differentials cause stratified thermal layers that inhibit uniform heating

Engineering Contradiction:
Improveoil heating capabilityVSAvoidthermal layer uniformity
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The heating function is segmented into multiple immersion heaters distributed throughout the oil pan, with each heater serving a specific zone. This segmentation allows for more uniform heat distribution and prevents large temperature differentials that would cause stratification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system introduces a vertical dimension to oil circulation by positioning the return line at a lower elevation than the oil inlet. Oil is pumped from the bottom of the pan, forced upward through the return line, and redistributed, creating vertical flow patterns that break thermal stratification.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If high power heating elements are used, then heating efficiency is improved, but coking and oil oxidation occur due to lack of oil flow

Engineering Contradiction:
Improveheating efficiencyVSAvoidcoking and oil oxidation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system ensures continuous oil circulation through the pump and return line, maintaining constant movement of oil past the heating elements. This continuous flow prevents oil from stagnating and overheating, eliminating the conditions that lead to coking and oxidation while maintaining heating efficiency.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system changes the operational parameters of the heating elements by using multiple lower-power elements instead of fewer high-power elements. This distribution of heating capacity across multiple elements, combined with continuous oil flow, maintains heating efficiency while preventing localized overheating that causes coking.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the oil pan structure is modified to improve heating, then heating performance is improved, but maintenance access becomes difficult

Engineering Contradiction:
Improveheating performanceVSAvoidmaintenance access
Core Design Contradiction:
TemperatureVSEase of repair

Solution Approach 1:

The heating system is segmented into removable immersion heater elements that can be independently accessed and maintained. The return line is also designed as a separate, accessible component with service ports, allowing maintenance without complete disassembly of the oil pan.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The immersion heaters are designed as extractable components that can be removed from the oil pan for maintenance or replacement. The return line is extracted as a separate serviceable component with accessible ports, allowing the heating system to be maintained without removing the entire oil pan or engine components.

Inventive Principle:
Principle #2Taking out (Extraction)

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 uniform oil heating, reducing temperature differentials and preventing coking, enabling the oil to reach a suitable temperature for engine use within a specified time, such as heating from 5°C to 55°C in less than four hours.

Implementation Method 1

a plurality of immersion heaters positioned at least partially within the oil pan

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a pump receiving oil from the oil outlet, and providing oil to the oil inlet

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 3

a return line positioned within the oil pan, coupled to the oil inlet, and including a plurality of apertures for providing oil into the oil pan, each aperture aligned with a corresponding one of the plurality of immersion heaters

Methodology Applied
Scientific EffectFluid flow through apertures:

Data Source

PatentEP3746644B1Oil heater for a generator set
Publication Date: 2022.10.19 CUMMINS POWER GENERATION IP INC
  • EP3746644B1 patent drawingFigure 1
  • EP3746644B1 patent drawingFigure 2
  • EP3746644B1 patent drawingFigure 3~5

AI summary

Systems and apparatuses include a generator set including an alternator, a transmission coupled to the alternator and structured to receive power from an engine, and an oil heating system including an oil pan structured to provide lubricating oil to the engine and including an oil outlet and an oil inlet, a plurality of immersion heaters positioned at least partially within the oil pan, a return line positioned within the oil pan, coupled to the oil inlet, and including a plurality of apertures for providing oil into the oil pan, each aperture aligned with a corresponding one of the plurality of immersion heaters, and a pump receiving oil from the oil outlet, and providing oil to the oil inlet.