Rotary Slide Valves for External Heat Source Engine

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Solution Overview

Problem

External hot source engines, such as those of the Ericsson type, face limitations in valve distribution systems, including high pressure losses, low valve lift, and energy consumption due to cam-driven mechanisms, which hinder efficient heat recovery and energy efficiency.

Innovation Solution

The implementation of a rotary valve system with internal passages in the cylinder head, synchronized with piston movement, allows for brief, low-pressure transfers of working gas through large passage sections, minimizing pressure losses and reducing the number of engine parts, size, and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If cam-actuated valves are used for gas distribution, then valve control is achieved, but pressure losses increase and valve lift is limited

Engineering Contradiction:

Improvevalve controlVSAvoidpressure losses

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces the cam-actuated mechanical valve system with a rotary valve mounted in rotation in the cylinder head. The rotary valve uses rotational movement to control gas flow between chambers, eliminating the need for cam mechanisms and reducing mechanical complexity while improving pressure flow characteristics through larger passage sections.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention transitions from linear valve lift motion to rotational valve movement. The rotary valve's rotational dimension allows for larger effective passage areas and better flow control, resolving the limitation of low valve lift in cam-actuated systems while maintaining effective gas distribution control.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of operation

If cam-driven valve distribution is used, then gas flow control is achieved, but energy consumption increases

Engineering Contradiction:

Improvegas flow controlVSAvoidenergy consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The rotary valve system replaces the energy-consuming cam-driven mechanism with a simpler rotational valve arrangement. The rotary valve can be driven directly by the engine's rotational motion or with minimal external energy input, eliminating the energy losses associated with cam follower mechanisms and reducing overall system energy consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If large passage sections are used for gas transfer, then pressure losses decrease, but device complexity increases

Engineering Contradiction:

Improvepressure lossesVSAvoiddevice complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent integrates the valve mechanism directly into the cylinder head structure, merging the distribution function with the existing engine components. The rotary valve is mounted in rotation in the cylinder head and uses internal passages that are part of the valve body itself, combining multiple functions into a single integrated component rather than adding separate complex systems.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The rotary valve serves multiple functions: it controls gas distribution between chambers, provides large passage sections for low-pressure loss flow, and integrates with the cylinder head structure. This multi-functional design achieves effective gas transfer without proportionally increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Productivity

If brief gas transfer periods are used, then cycle efficiency improves, but valve timing precision requirements increase

Engineering Contradiction:

Improvecycle efficiencyVSAvoidvalve timing precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The rotary valve provides dynamic control of gas transfer timing through its rotational position. The valve can be synchronized with the piston movement to achieve brief, precise transfer periods that improve cycle efficiency. The rotational mechanism allows for easy adjustment of timing without complex mechanical linkages, maintaining precision while improving productivity.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3662153B1External heat source engine with slide valves

Publication Date: 2024.06.19 HEVATECH

Figure 1a~2c
Figure 3~4
Figure 5a~5b

AI summary

The present invention concerns an external heat source engine comprising: - at least one cylinder (2), - a piston (3) that is movable back and forth in the cylinder, - a cylinder head (4) defining a working chamber (5) with the piston and the cylinder, - a heat exchanger (6) for exchanging heat between a working gas and a heat-transfer fluid, - a distribution comprising two rotary slide valves (20, 30) mounted so as to be able to rotate in the cylinder head and bringing the working chamber selectively into communication with the following resources: o a working gas inlet (A), o a cold end (B) of the exchanger, o a hot end (C) of the exchanger, o an exhaust (D). The slide valves (20, 30) comprise internal passages that open through the side wall of same through at least one opening that communicates selectively with the working chamber (5) via at least one opening formed in the cylinder head (4).