Method of operating a heat pump for avoiding freezing

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Solution Overview

Problem

Current heat pumps using a cold heat transfer liquid face issues such as excessive water usage, high energy consumption, and freezing risks due to fixed flow settings, leading to inefficient performance and potential damage during heating and cooling operations.

Innovation Solution

Implementing a temperature-controlled valve system that adjusts the flow of the cold heat transfer liquid based on real-time temperature monitoring, using a PID control method to maintain optimal temperature differences and prevent freezing, thereby minimizing water consumption and energy usage while ensuring proper functioning across various operating modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed high flow setting is used to guarantee problem-free functioning, then reliability is improved, but water consumption increases and energy consumption increases

Engineering Contradiction:
Improveproblem-free functioningVSAvoidwater consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies dynamics by replacing the fixed flow setting with a dynamically adjustable flow control valve that continuously adapts the cold heat transfer liquid flow rate based on real-time temperature measurements from the evaporator and ambient environment sensors, allowing the system to maintain reliability while optimizing water consumption across varying operating conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by using temperature sensors to monitor evaporator temperature and ambient conditions, then feeding this information back to the controller which adjusts the flow control valve position accordingly, creating a closed-loop system that maintains reliable operation while minimizing water usage based on actual thermal demands

Inventive Principle:
Principle #23Feedback

2Reliability

If a fixed high flow setting is used to guarantee problem-free functioning, then reliability is improved, but energy consumption increases

Engineering Contradiction:
Improveproblem-free functioningVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the flow rate through the flow control valve based on real-time temperature conditions, reducing the energy required to pump water when high flow is not thermally necessary, while maintaining high flow settings only when required for reliable heat pump operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Temperature feedback from evaporator and ambient sensors enables the controller to optimize pump energy consumption by adjusting flow rates to match actual thermal demands, preventing unnecessary energy expenditure while maintaining system reliability

Inventive Principle:
Principle #23Feedback

3Reliability

If a fixed high flow setting is used, then reliability is improved, but the temperature difference on the cold side decreases

Engineering Contradiction:
Improveproblem-free functioningVSAvoidtemperature difference on cold side
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The flow control valve dynamically adjusts the cold heat transfer liquid flow rate to maximize the temperature difference across the evaporator by reducing flow when thermal demand is low, thereby improving heat pump efficiency while maintaining reliable operation through continuous monitoring and adjustment

Inventive Principle:
Principle #15Dynamics

4Quantity of substance

If the flow is reduced to minimize water usage, then water consumption decreases, but freezing risk increases

Engineering Contradiction:
Improvewater consumptionVSAvoidfreezing risk
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

Temperature feedback from evaporator sensors enables the controller to maintain minimum flow rates required to prevent freezing when ambient temperatures drop, while allowing flow reduction during warmer conditions, thus minimizing water consumption without compromising system safety

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system takes preliminary anti-action by proactively monitoring ambient temperature and evaporator temperature to anticipate freezing conditions, adjusting the flow rate in advance to prevent freezing before it occurs, thereby enabling flow reduction during safe operating conditions

Inventive Principle:
Principle #9Preliminary anti-action

5Use of energy by moving object

If the flow is reduced to minimize energy consumption, then energy usage decreases, but freezing risk increases

Engineering Contradiction:
Improveenergy consumptionVSAvoidfreezing risk
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

Temperature feedback control enables the system to minimize pump energy consumption by reducing flow rates during warm conditions while automatically maintaining sufficient flow to prevent freezing when temperature sensors detect cold conditions, optimizing the energy-safety trade-off dynamically

Inventive Principle:
Principle #23Feedback

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 solution effectively reduces water usage and energy consumption, maintains optimal temperature differences, and prevents freezing, ensuring stable operation and efficient performance during heating, cooling, and domestic hot water production.

Implementation Method 1

Implementing a temperature-controlled valve system that adjusts the flow of the cold heat transfer liquid based on real-time temperature monitoring, using a PID control method to maintain optimal temperature differences and prevent freezing

Methodology Applied
Scientific EffectTemperature monitoring and control:

Implementation Method 2

heat pumps of the kind extracting thermal energy from a cold thermal energy source such as the ground, sea water or other external source in the environment having exchanged thermal energy with a cold heat transfer liquid

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2674682B1Method of operating a heat pump for avoiding freezing
Publication Date: 2020.05.06 THERMIA
  • EP2674682B1 patent drawingFigure 1~3
  • EP2674682B1 patent drawing

AI summary

The invention relates to a method for operating a heat pump by use of a valve unit comprising at least one control valve in connection with the inlet of cold liquid circuit. The valve unit also comprises a sensor coupled to a heat pump controller. The heat pump controller constantly monitors the second temperature at a location between, and including, the inlet and the outlet of the first heat exchanger. The heat pump controller transmits a signal to the valve unit at least when the temperature of the cold liquid is below a threshold temperature, and the valve unit starts to increase the opening degree of the control valve when having received the signal from the heat pump controller. The invention also relates to a valve unit and to a heat pump with such valve unit.