Thermal storage system

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The energy consumption efficiency of heat accumulating operations in heat pump systems decreases due to low temperatures of the compressor and heat exchanger at the start, leading to increased amounts of low-temperature hot water flowing into the storage tank, which reduces overall efficiency.

Innovation Solution

A heat storage system with a compressor, heat storage tank, and heat exchange means, including a control mechanism that initially maintains a lower compressor frequency and subsequently increases it to enhance energy efficiency by reducing low-temperature water flow and minimizing medium-temperature water accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the compressor operates at high frequency from the start of heat accumulating operation, then the heating capacity increases, but the compressor and heat exchanger temperatures remain too low, causing low-temperature hot water to flow into the storage tank and reducing energy efficiency

Engineering Contradiction:
Improveheating capacityVSAvoidcompressor and heat exchanger temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The system performs preliminary heating by operating the compressor at high frequency before the heat accumulating operation starts, pre-heating the compressor and heat exchanger to reduce the amount of low-temperature hot water flowing into the storage tank during subsequent operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The compressor operating frequency is dynamically adjusted based on real-time temperature conditions. The control unit increases frequency when temperatures are low to boost heating capacity, and reduces frequency when temperatures are sufficient to maintain energy efficiency, creating an adaptive operational mode

Inventive Principle:
Principle #15Dynamics

2Productivity

If the compressor operating frequency is increased to maintain target hot water temperature, then the heating efficiency improves, but the energy consumption increases

Engineering Contradiction:
Improveheating efficiencyVSAvoidcompressor energy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The compressor operating frequency is dynamically adjusted based on real-time temperature conditions. The control unit increases frequency when temperatures are low to boost heating capacity, and reduces frequency when temperatures are sufficient to maintain energy efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operating parameters (frequency) of the compressor based on temperature conditions. By adjusting the frequency parameter according to actual thermal states, the system optimizes the balance between heating efficiency and energy consumption

Inventive Principle:
Principle #35Parameter changes

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 prevents a decrease in energy consumption efficiency by reducing the amount of medium-temperature water in the tank, thereby maintaining higher energy efficiency throughout the heat accumulating operation.

Implementation Method 1

a compressor (3) for compressing refrigerant

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

heat exchange means for heating the heating medium using heat of the refrigerant compressed by the compressor

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3967948B1Thermal storage system
Publication Date: 2023.08.30 MITSUBISHI ELECTRIC CORP
  • EP3967948B1 patent drawingFigure 1
  • EP3967948B1 patent drawingFigure 2
  • EP3967948B1 patent drawingFigure 3

AI summary

A heat storage system includes a compressor that compresses refrigerant; a heat storage tank that stores a heating medium; heat exchange means provided outside the heat storage tank for heating the heating medium using heat of the refrigerant compressed by the compressor; a heat accumulating circuit including a feed path that feeds the heating medium flowing out of the heat storage tank to the heat exchange means, a return path that returns the heating medium heated by the heat exchange means into the heat storage tank, and a pump that circulates the heating medium; and control means capable of executing an initial operation that controls an operating frequency of the compressor at the beginning of a heat accumulating operation in which the heating medium heated by the heat exchange means is accumulated in the heat storage tank. The initial operation includes a first operation that maintains the operating frequency at a first frequency and, after the first operation, a second operation that maintains the operating frequency at a second frequency higher than the first frequency.