Marine Engine Open Loop Cooling Pre-Heating

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Solution Overview

Problem

Existing marine engine cooling systems face issues with condensation accumulation in the exhaust manifold and exhaust tube, which can adversely affect engine operation and catalyst/sensor performance due to inadequate temperature control of the cooling water.

Innovation Solution

An open loop cooling circuit with a heat exchanger is employed to pre-heat the cooling water before it enters the exhaust tube and exhaust manifold cooling jackets, reducing condensation by managing the temperature gradient and flow rates, and a bypass passage system is used to ensure efficient heat exchange and prevent overheating of components like the fuel module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling water is used to cool the exhaust manifold and exhaust tube, then the temperature of exhaust components is reduced, but condensation accumulates in the exhaust gases adversely affecting engine operation and catalyst/sensor performance

Engineering Contradiction:

Improveexhaust component temperatureVSAvoidcondensation accumulation

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The cooling circuit is divided into separate loops: a first cooling circuit cools the engine block and cylinder head, while a second cooling circuit specifically cools the exhaust manifold and exhaust tube. This segmentation allows independent temperature control of different components, enabling the exhaust components to be cooled without causing condensation issues that would affect engine operation and catalyst/sensor performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different cooling strategies are applied to different parts of the system. The engine block and cylinder head receive cooling from the first circuit, while the exhaust manifold and exhaust tube receive cooling from the second circuit. This local differentiation allows the exhaust components to be cooled to appropriate temperatures without creating condensation problems, as the cooling parameters can be optimized specifically for each component's requirements.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If a heat exchanger is used to pre-heat cooling water, then condensation is reduced by managing temperature gradient, but device complexity increases

Engineering Contradiction:

ImprovecondensationVSAvoidcooling circuit complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The heat exchanger integrates the pre-heating function into the existing cooling circuit system. By combining the heat exchange function with the cooling water circulation, the system pre-heats cooling water before it enters the exhaust tube and exhaust manifold cooling jackets, reducing condensation without requiring a completely separate system. This merging approach manages the temperature gradient effectively while minimizing the increase in device complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively reduces condensation in the exhaust gases, improving marine engine performance and preventing adverse effects on catalysts and sensors by optimizing the temperature of the cooling water and ensuring efficient heat transfer and distribution.

Implementation Method 1

A heat exchanger is configured to cause an exchange of heat between the cooling water located upstream of the marine engine and the cooling water located downstream of the marine engine to thereby warm the cooling water located upstream of the marine engine prior to cooling the marine engine

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

the cooling water...warms the raw cooling water, and thereafter conveys the warmed cooling water to cool the cylinder block, the cylinder head, the exhaust manifold, and the exhaust tube

Methodology Applied

Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 3

reducing condensation by managing the temperature gradient and flow rates

Methodology Applied

Scientific EffectCondensation reduction through temperature gradient management: Temperature Gradient

Implementation Method 4

A pump is configured to pump the cooling water from upstream to downstream through the open loop cooling circuit

Methodology Applied

Scientific EffectPumping: Pump

Implementation Method 5

heat is exchanged between the cooling water and the marine engine

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 6

convey cooling water from the body of water to the marine engine so that heat is exchanged between the cooling water and the marine engine

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS9403588B1Open loop cooling systems and methods for marine engines

Publication Date: 2016.08.02 BRUNSWICK CORP

AI summary

Systems are for cooling a marine engine that is operated in a body of water. The systems can include an open loop cooling circuit for cooling the marine engine, wherein the open loop cooling circuit is configured to convey cooling water from the body of water to the marine engine so that heat is exchanged between the cooling water and the marine engine, and a pump that is configured to pump the cooling water from upstream to downstream through the open loop cooling circuit. A heat exchanger is configured to cause an exchange of heat between the cooling water located upstream of the marine engine and the cooling water located downstream of the marine engine to thereby warm the cooling water located upstream of the marine engine, prior to cooling the marine engine.