Heat Pump Scale Detection Using Two Temperature Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heat pump systems face difficulties in accurately determining performance degradation due to scale build-up in water/refrigerant heat exchangers, as they require detection of multiple temperature positions and complex calculations, making it challenging to recognize and address the issue before capacity deficiency, higher power consumption, or shutdown occur.

Innovation Solution

A heat pump system that determines performance degradation based on the temperature difference between the refrigerant outlet and water inlet temperatures of the water/refrigerant heat exchanger, allowing for easy and accurate detection using only two temperature sensors, and includes an alarm system to notify users of maintenance needs, thereby preventing system failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple temperature sensors and complex calculations are used to detect performance degradation, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveperformance degradation detection accuracyVSAvoidnumber of temperature sensors and calculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts only the essential temperature parameters needed for performance degradation detection. Instead of using multiple temperature sensors as in conventional methods, it selectively uses only two temperature sensors to detect the refrigerant outlet temperature and water inlet temperature, simplifying the detection system while maintaining adequate measurement precision for determining scale build-up in the heat exchanger

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention inverts the conventional approach by not directly measuring all temperature parameters but instead using the temperature difference between refrigerant outlet and water inlet as an indirect indicator of performance degradation. This inversion simplifies the measurement system while still enabling accurate detection of heat exchanger efficiency changes

Inventive Principle:
Principle #13The other way round (Inversion)

2Stability of the object's composition

If the system controls water volume to maintain target hot water temperature, then hot water delivery temperature stability is improved, but the ability to recognize performance degradation deteriorates

Engineering Contradiction:
Improvehot water delivery temperature stabilityVSAvoidperformance degradation recognition capability
Core Design Contradiction:
Stability of the object's compositionVSLoss of information

Solution Approach 1:

The invention introduces a feedback mechanism that monitors the temperature difference between refrigerant outlet and water inlet. When scale build-up occurs and heat exchanging performance degrades, this temperature difference changes, providing feedback information about system performance. This allows the system to maintain stable hot water delivery temperature through water pump control while simultaneously detecting performance degradation through the temperature difference feedback

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention uses the temperature difference between refrigerant outlet and water inlet as an intermediary parameter to detect performance degradation. This intermediary measurement does not interfere with the hot water temperature control function but provides indirect information about heat exchanger performance, enabling simultaneous temperature stability and degradation detection

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 enables the heat pump system to accurately detect performance degradation and alert users to perform maintenance, preventing capacity deficiencies, power consumption issues, and shutdowns, while maintaining system stability and performance, even when scale build-up degrades heat exchanging efficiency.

Implementation Method 1

a water/refrigerant heat exchanger (5) which, through heat exchange between a refrigerant and water, heats the water and produces hot water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2706303B1Heat pump system
Publication Date: 2019.03.06 MITSUBISHI HEAVY IND THERMAL SYST
  • EP2706303B1 patent drawingFigure 1
  • EP2706303B1 patent drawingFigure 2
  • EP2706303B1 patent drawingFigure 3

AI summary

In a type of heat pump system which includes a water/refrigerant heat exchanger (5) and controls a water volume by a water pump (12) such that a temperature of hot water delivered from the heat pump system meets a target temperature, a performance degradation determining part (23) is provided, which determines performance degradation due to scale build-up of the water/refrigerant heat exchanger (5) on the basis of the temperature of the delivered hot water and a temperature difference between a refrigerant outlet temperature and a water inlet temperature of the water/refrigerant heat exchanger (5).