Multi-Indoor Air Conditioner Heating Restart Temperature Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air conditioner systems face challenges in accurately measuring room temperature during heating operations, leading to delayed heating restarts due to increased pressure and potential overheating or unheating issues, as the intake-air temperature sensor is affected by high-temperature refrigerant flow, causing inaccurate temperature readings.

Innovation Solution

The air conditioner employs measuring units to monitor air temperatures and a control unit that corrects these readings at predetermined intervals, comparing the corrected temperatures to a heating restart temperature, thereby adjusting the heating operation timing to prevent non-heating or overheating by increasing or decreasing the correction value based on the elapsed time since the last heating operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If high-temperature, high-pressure refrigerant is made to flow into the indoor unit carrying out heating thermostat operation to reduce pressure increase, then the pressure in heat exchangers is reduced, but the room becomes unheated due to inaccurate temperature measurement

Engineering Contradiction:
Improvepressure in heat exchangersVSAvoidroom air temperature measurement accuracy
Core Design Contradiction:
Stress or pressureVSMeasurement precision

Solution Approach 1:

The patent introduces a correction value as an intermediary element between the measured temperature and the actual room temperature. The correction value compensates for the radiant heat effect from the refrigerant, allowing the system to accurately determine the actual room temperature despite the sensor being exposed to high-temperature refrigerant flow.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter used for temperature control by introducing a correction value that adjusts the measured temperature. This parameter change allows the system to account for the radiant heat effect and accurately reflect the actual room temperature, resolving the measurement inaccuracy problem.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If the thermostat ON point is shifted by a predetermined value to prevent room from being unheated, then the heating operation restarts timely, but the room becomes overheated

Engineering Contradiction:
Improvetime delay in heating restartVSAvoidroom air temperature control accuracy
Core Design Contradiction:
Loss of timeVSTemperature

Solution Approach 1:

The patent implements a feedback mechanism where the correction value is dynamically adjusted based on the operating time during heating thermostat operation. The control unit updates the correction value at predetermined time intervals, allowing the system to adapt to changing thermal conditions and prevent both unheating and overheating.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the correction value dynamic rather than fixed. The correction value changes based on the operating time, allowing the system to adapt to the changing thermal environment as walls and objects in the room gradually warm up, thereby preventing both unheating and overheating conditions.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the intake-air temperature sensor measures temperature during heating thermostat operation, then the temperature reading is affected by radiant heat from refrigerant, but the heating operation can be controlled based on this reading

Engineering Contradiction:
Improveheating operation controlVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The correction value serves as an intermediary that bridges the gap between the measured temperature (affected by radiant heat) and the actual room temperature. This allows the system to maintain ease of operation using the temperature sensor while compensating for measurement inaccuracies through the correction mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This solution enhances the controllability of room temperature by ensuring timely heating operation restarts, preventing both unheating and overheating by accurately accounting for the radiant heat effects on temperature measurements, thus maintaining optimal comfort levels.

Implementation Method 1

there is a possibility that the intake-air temperature sensor will measure a temperature higher than the actual room air temperature due to the heat of the high-temperature, high-pressure refrigerant (for example, radiant heat) flowing in the one indoor unit

Methodology Applied
Scientific EffectRadiant heat: Thermal Radiation

Data Source

PatentEP2527757B1Air conditioner
Publication Date: 2018.06.06 MITSUBISHI HEAVY IND THERMAL SYST
  • EP2527757B1 patent drawingFigure 1
  • EP2527757B1 patent drawingFigure 2
  • EP2527757B1 patent drawingFigure 3

AI summary

Provided is an air conditioner in which controllability of room temperature can be enhanced by suitably controlling the time at which a heating thermostat operation is stopped. Provided is an air conditioner (1) including a plurality of indoor units (4A, 4B, 4C, and 4D) for a single outdoor unit (2), in which a heating operation can be stopped in one indoor unit (4A) and heating operations can be performed in the other indoor units (4B, 4C, and 4D), the air conditioner (1) including measuring units (42) that measure the temperatures of air taken into the indoor units (4A, 4B, 4C, and 4D); and a control unit (6) that controls restarting of the next heating operation in the one indoor unit (4A) in which the heating operation is stopped by correcting the measured temperature of the measuring unit (42) at predetermined time intervals and by comparing the corrected measured temperature and a heating restart temperature, wherein the correction of the measured temperature is a correction whereby the absolute value of a subtraction value for the measured temperature increases according to the time that has passed after the heating operation is stopped.