Heat Pump Water Heater Control for Adaptive Turn-On Thresholds

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current heat pump water heaters face reliability and energy efficiency issues due to fixed turn-on temperature differences, leading to frequent on-off cycles at high ambient temperatures and delayed turn-on at low temperatures, which affect user comfort and system reliability.

Innovation Solution

A method and system for controlling heat pump water heaters that dynamically adjust the turn-on temperature difference based on ambient and set temperatures, using a processor to determine a turn-on threshold, ensuring the heat pump turns on only when necessary to maintain user comfort and system reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed turn-on temperature difference is used, then the control logic is simple and easy to implement, but the heat pump turns on and off frequently at high ambient temperatures and delays turn-on at low temperatures, affecting reliability and energy efficiency

Engineering Contradiction:
Improvecontrol logic simplicityVSAvoidheat pump system reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the turn-on temperature difference dynamic rather than fixed. The controller adjusts the turn-on temperature difference based on ambient temperature conditions: using a first turn-on temperature difference when ambient temperature is above a threshold, and a second turn-on temperature difference when ambient temperature is at or below the threshold. This dynamic adjustment prevents frequent on-off cycles at high temperatures and ensures timely heating at low temperatures, thereby improving system reliability while maintaining manageable control logic through predefined adjustment rules.

Inventive Principle:
Principle #15Dynamics

2Productivity

If a small fixed turn-on temperature difference is used, then the water temperature control is responsive, but the main engine turns on and off frequently at high ambient temperatures, increasing operation load and wasting energy

Engineering Contradiction:
Improvewater temperature control responsivenessVSAvoidenergy waste from frequent cycling
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by modifying the turn-on temperature difference parameter based on ambient temperature conditions. When ambient temperature is high (above threshold), a larger first turn-on temperature difference is used to reduce the frequency of heat pump activation. When ambient temperature is low (at or below threshold), a smaller second turn-on temperature difference is used to maintain responsive water temperature control. This parameter adjustment strategy reduces energy waste from frequent cycling while preserving temperature control responsiveness when needed.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If a large fixed turn-on temperature difference is used, then the heat pump runs under high load conditions continuously, but this seriously affects the reliability of the heat pump system

Engineering Contradiction:
Improveheating capacityVSAvoidheat pump system reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by adjusting the turn-on temperature difference based on ambient temperature to optimize the balance between heating capacity and system reliability. When ambient temperature is high, a larger first turn-on temperature difference allows the heat pump to operate more continuously at moderate load, improving reliability. When ambient temperature is low, a smaller second turn-on temperature difference enables the heat pump to operate in shorter, more intensive cycles, preventing continuous high-load operation and associated reliability issues. This dynamic parameter adjustment optimizes both productivity and reliability across different operating conditions.

Inventive Principle:
Principle #15Dynamics

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 approach improves user comfort and reduces the load on the heat pump system by intelligently controlling the turn-on threshold, enhancing both user experience and system reliability by optimizing energy usage and reducing frequent start-ups.

Implementation Method 1

a heat pump system to turn on so as to heat the water in the water tank

Methodology Applied
Scientific EffectHeat pump: Heat Exchanger

Data Source

PatentEP3232134B1System for controlling a water heater comprising a heat pump and associated method
Publication Date: 2020.05.27 GD MIDEA HEATING & VENTILATING EQUIP CO LTD
  • EP3232134B1 patent drawingFigure 1~2
  • EP3232134B1 patent drawingFigure 3~4
  • EP3232134B1 patent drawing

AI summary

A heat pump hot water machine control method, for controlling a heat pump system of the heat pump hot water machine to turn on and heat water in a water tank, and the method comprising the following steps: receiving a turn-on instruction; detecting the current temperature of the water in the water tank and the ambient temperature; acquiring a turn-on temperature difference according to the setting temperature of the heat pump hot water machine and the ambient temperature, and acquiring a turn-on threshold according to the turn-on temperature difference; determining whether the current temperature is less than the turn-on threshold; if not, then maintaining the current state; and if so, then controlling to enable the heat pump system to heat the water in the water tank. Also disclosed is a heat pump hot water machine control system.