Air conditioning and ventilation system

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air-conditioning ventilation systems fail to maintain an appropriate ventilation rate over time, leading to insufficient ventilation when the rate is set too low for extended periods, despite efforts to reduce power consumption by controlling ventilation based on air-conditioning apparatus power consumption.

Innovation Solution

An air-conditioning ventilation system with a controller that adjusts the ventilation rate of the ventilation device to ensure the integrated ventilation value remains within a standard range, switching from 'low' to 'high' when the integrated value approaches the lower limit to prevent insufficient ventilation, and vice versa, maintaining optimal ventilation levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the ventilation rate is reduced to lower power consumption of the air-conditioning apparatus, then energy efficiency improves, but the ventilation amount becomes insufficient over time

Engineering Contradiction:
Improvepower consumption of air-conditioning apparatusVSAvoidventilation amount
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The ventilation rate is made dynamically adjustable based on accumulated ventilation deficiency. The system transitions from a static fixed ventilation rate to a dynamic rate that increases when ventilation deficiency accumulates and decreases when the integrated value is within the standard range, resolving the contradiction between energy efficiency and ventilation reliability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller monitors the integrated ventilation value and provides feedback to adjust the ventilation rate accordingly. When the integrated value exceeds the standard range, the system increases ventilation rate; when within range, it reduces rate, creating a closed-loop control system that balances energy consumption with ventilation requirements

Inventive Principle:
Principle #23Feedback

2Reliability

If the ventilation rate is increased to maintain adequate ventilation, then ventilation reliability improves, but power consumption of the air-conditioning apparatus increases

Engineering Contradiction:
Improveventilation amountVSAvoidpower consumption of air-conditioning apparatus
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system applies partial ventilation (reduced rate) when conditions permit, and excessive ventilation (increased rate) only when necessary to correct accumulated deficiency. This selective application of ventilation intensity optimizes the balance between energy consumption and ventilation reliability

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The ventilation rate varies periodically based on the accumulation and correction cycles of ventilation deficiency. The system alternates between high-rate correction periods and low-rate maintenance periods, reducing overall energy consumption while ensuring adequate ventilation over time

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3910256B1Air conditioning and ventilation system
Publication Date: 2023.11.22 MITSUBISHI ELECTRIC CORP
  • EP3910256B1 patent drawingFigure 1~2
  • EP3910256B1 patent drawingFigure 3~5
  • EP3910256B1 patent drawingFigure 6

AI summary

An air-conditioning ventilation system includes a ventilation device configured to ventilate an air-conditioned space while controlling a ventilation rate, an air-conditioning apparatus that includes a heat exchanger configured to exchange heat between refrigerant and air and that is configured to operate while controlling an air-conditioning capacity thereof to bring an indoor temperature in the air-conditioned space to a setting temperature, and a controller. The controller performs normal control that causes the ventilation device to operate to ventilate the air-conditioned space at a ventilation rate corresponding to the air-conditioning capacity of the air-conditioning apparatus, and recovery control that controls the ventilation rate of the ventilation device such that an integrated value of an amount of ventilation for a time duration from activation of the ventilation device under the normal control falls within a standard ventilation range including a standard integrated value of an amount of ventilation obtained by causing the ventilation device to operate to ventilate the air-conditioned space at a standard ventilation rate for a time duration having a same length as the time duration.