Air conditioning system control device, outdoor unit, relay unit, heat source unit, and air conditioning system

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Solution Overview

Problem

In indirect air conditioning systems, the varying lengths and number of bent portions of water pipes between indoor and relay units create flow resistance issues, making it difficult to determine the appropriate capacity of the water pump, which can result in insufficient heating and/or cooling performance.

Innovation Solution

A controller is implemented that adjusts the performance of the heat source or cold source by varying the pump capacity and controlling the flow rate and temperature of the second heat medium (water or brine) to maintain optimal heating and cooling performance, using a combination of flow rate control valves, pressure sensors, and temperature sensors to ensure the indoor air conditioning performance meets the required standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a water pump with sufficient capacity is installed to handle varying pipe resistances, then heating and cooling performance is maintained, but device complexity and cost increase

Engineering Contradiction:
Improveheating and cooling performanceVSAvoidpump capacity selection
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the pump capacity adjustable rather than fixed. The controller dynamically changes the pump's operating capacity based on real-time feedback from flow rate and temperature sensors, allowing the system to adapt to varying pipe resistances and maintain optimal performance without requiring an oversized pump for all conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the pump's operating parameters (flow rate and speed) based on detected conditions. The controller adjusts pump parameters in response to sensor data, enabling the same pump to operate effectively across different pipe configurations and resistance levels.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a water pump with smaller capacity is installed to reduce cost, then device complexity is reduced, but heating and cooling performance becomes insufficient

Engineering Contradiction:
Improvepump capacity selectionVSAvoidheating and cooling performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The controller dynamically adjusts the pump's operating capacity to match actual system needs, allowing a smaller pump to deliver performance equivalent to a larger fixed-capacity pump. The pump operates at variable speeds and flow rates based on real-time conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from flow rate sensors and temperature sensors to continuously monitor performance and adjust pump operation accordingly. This closed-loop control ensures that the pump delivers adequate performance even when installed with lower capacity than traditionally required.

Inventive Principle:
Principle #23Feedback

3Reliability

If the pump capacity is increased to compensate for insufficient initial selection, then heating and cooling performance is maintained, but energy consumption increases

Engineering Contradiction:
Improveheating and cooling performanceVSAvoidpump energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The pump operates dynamically at variable capacities rather than running at maximum capacity continuously. The controller adjusts the pump's speed and flow rate to match actual system demands, reducing energy consumption when full capacity is not needed while maintaining adequate performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the pump's operating parameters (speed, flow rate) based on detected conditions and performance requirements. This allows the pump to operate efficiently across different load conditions, consuming only the energy necessary to maintain adequate heating and cooling performance.

Inventive Principle:
Principle #35Parameter changes

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 controller ensures that the heating and/or cooling performance is maintained within an appropriate range by increasing or decreasing the performance of the heat source or cold source as needed, even when the pump has an insufficient capacity, thereby preventing insufficient air conditioning performance.

Implementation Method 1

a first heat medium circuit using a first heat medium, and a second heat medium circuit using a second heat medium, a heat source apparatus having a heat exchanger that exchanges heat between the first heat medium and the second heat medium

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a pump that circulates the second heat medium between the plurality of third heat exchangers and the heat exchanger

Methodology Applied
Scientific EffectFluid circulation: Pump

Implementation Method 3

a plurality of third heat exchangers that exchange heat between the second heat medium and indoor air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3779323B1Air conditioning system control device, outdoor unit, relay unit, heat source unit, and air conditioning system
Publication Date: 2023.02.22 MITSUBISHI ELECTRIC CORP
  • EP3779323B1 patent drawingFigure 1
  • EP3779323B1 patent drawingFigure 2~3
  • EP3779323B1 patent drawingFigure 4

AI summary

When a state in which a driving voltage of a pump (23) is set to an upper limit voltage and an opening degree of at least one of a plurality of flow rate control valves (33, 43, 53) is set to a maximum opening degree continues for a first determination time period (TP1), an operation frequency of a compressor (11) is raised at a first time (t2) so as to increase an amount of heat exchange by a second heat exchanger (22). When an operation stop request is input, or an indoor temperature (Tr) reaches a set temperature (Trs), in at least one of a plurality of third heat exchangers (31, 41, 51) after the first time (t2), the operation frequency (fc) of the compressor (11) is lowered or the driving voltage (Vp) of the pump (23) is lowered.