Heat Pump Hot-Water Scheduling for Outside Temperature COP

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional heat pump hot-water supply systems fail to achieve power savings despite operating during low electricity rates, as the coefficient of performance (COP) varies with outside air temperature, leading to increased power consumption during higher temperatures.

Innovation Solution

A control device that estimates outside air temperatures for the current and next day to determine the optimal operating time zone for the heat pump hot-water supply device, operating it when temperatures are higher to minimize power consumption and align with lower electricity rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the heat pump hot-water supply device is operated during nighttime when electricity rate is low, then operating cost is reduced, but power consumption increases due to lower outside air temperature

Engineering Contradiction:
Improvepower consumptionVSAvoidoperating cost
Core Design Contradiction:
Loss of energyVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary action by storing hot water in advance during periods of favorable temperature conditions. The control device predicts future outside air temperatures and operates the heat pump in advance when temperatures are higher, storing hot water in the storage tank before the period when hot water is needed, thereby avoiding operation during cold periods with high power consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies dynamics by making the operation timing flexible and adaptive rather than fixed. The control device dynamically adjusts the operation schedule based on predicted outside air temperatures, selecting optimal time zones where temperatures are comparatively high. This dynamic approach allows the system to operate when conditions are favorable rather than following a rigid nighttime-only schedule.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the heat pump hot-water supply device is operated when outside air temperature is low, then electricity rate is low, but the coefficient of performance (COP) decreases leading to higher power consumption

Engineering Contradiction:
Improveoperating scheduleVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The system implements feedback by continuously monitoring and predicting outside air temperatures, then using this information to adjust operation timing. The control device acquires predicted temperature data, compares it with operation requirements, and feedback-adjusts the operation schedule to select time zones with comparatively high temperatures, thereby maintaining high COP and low power consumption.

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

This approach enables power savings by operating the heat pump during time zones with higher outside air temperatures, reducing overall energy expenditure while maintaining the same heating capacity.

Implementation Method 1

a heat pump hot-water supply device (1), which absorbs heat from the outside air and supplies hot water

Methodology Applied
Scientific EffectHeat pump: Heat Exchanger

Implementation Method 2

a storage tank (2) for storing hot water obtained by operating the heat pump hot-water supply device (1)

Methodology Applied
Scientific EffectThermal energy storage: Thermal Energy Storage

Data Source

PatentEP2484987B1Heat pump hot-water supply system
Publication Date: 2015.10.07 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2484987B1 patent drawingFigure 1
  • EP2484987B1 patent drawingFigure 2
  • EP2484987B1 patent drawingFigure 3

AI summary

A heat pump hot-water supply system includes a heat pump hot-water supply device, a storage tank for storing hot water obtained by operating the heat pump hot-water supply device, and a control device for controlling starting/stopping of the heat pump hot-water supply device. The control device estimates an outside air temperature of a place where the heat pump hot-water supply device is installed and determines an operating time zone of the heat pump hot-water supply device based on an estimated value of the outside air temperature.