Building Heat Pump Control Using Dual Thermal Storage State of Charge

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Solution Overview

Problem

Current energy management systems for buildings rely heavily on electric energy management, neglecting thermal energy demand, which exceeds electric demand, leading to inefficiencies and high electricity grid dependency, especially when renewable energy is not available.

Innovation Solution

An energy management system integrating a heat pump, thermal energy storage devices for domestic hot water and space heating, and a renewable energy generation device, controlled by a controller that prioritizes charging based on the state of charge of these devices and renewable energy availability to maximize self-sufficiency and reduce grid interaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thermal energy storage devices are integrated into the energy management system, then self-sufficiency is improved and electricity grid interaction is reduced, but device complexity increases

Engineering Contradiction:
Improveself-sufficiencyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system segments thermal energy storage into two distinct devices: a first thermal energy storage device for domestic hot water and a second thermal energy storage device for space heating. Each device has its own state of charge analyser, allowing independent monitoring and control. This segmentation enables targeted charging strategies for different thermal demands while maintaining overall system coordination through the controller.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The controller implements a universal management system that coordinates multiple energy sources (renewable energy generation device, heat pump, electricity grid) and multiple storage devices (first and second thermal energy storage devices). The controller universally monitors state of charge from both analysers and dynamically routes energy flows to optimize self-sufficiency across different operational scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If state of charge analysers are used for both thermal energy storage devices, then energy management precision is improved, but measurement and control complexity increases

Engineering Contradiction:
Improvestate of charge determination accuracyVSAvoidcontrol complexity
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

Each thermal energy storage device is equipped with its own dedicated state of charge analyser, providing localized and precise measurement of energy levels specific to each storage device. The first state of charge analyser monitors the domestic hot water storage device, while the second state of charge analyser monitors the space heating storage device, allowing tailored charging decisions for each thermal demand type.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system implements feedback loops where state of charge data from both analysers is continuously fed to the controller. The controller processes this feedback information and dynamically adjusts charging operations of the renewable energy generation device and heat pump, as well as discharge operations, to maintain optimal energy levels in both thermal storage devices based on current needs and availability.

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 enhances self-sufficiency by shifting thermal energy demand to align with renewable energy availability, reducing unnecessary charging and maintaining energy reserves for non-renewable times, thereby increasing the use of renewable energy and minimizing electricity grid interaction.

Implementation Method 1

at least one heat pump

Methodology Applied
Scientific EffectHeat pump operation: Heat Exchanger

Implementation Method 2

PV generation from solar irradiance

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 3

at least one first thermal energy storage device for providing domestic hot water, at least one second thermal energy storage device for providing space heating

Methodology Applied
Scientific EffectThermal energy storage: Thermal Energy Storage

Data Source

PatentEP4253848B1Energy management system for a building and method of using the energy management system
Publication Date: 2024.11.20 MITSUBISHI ELECTRIC R&D CENTRE EUROPE BV
  • EP4253848B1 patent drawingFigure 1A
  • EP4253848B1 patent drawingFigure 1B
  • EP4253848B1 patent drawingFigure 1C

AI summary

The present invention relates to an energy management system for a building, comprising at least one heat pump, at least one first thermal energy storage device for providing domestic hot water, at least one second thermal energy storage device for providing space heating, at least one renewable energy generation device, at least one first state of charge analyser for determining the state of charge of the at least one first thermal energy storage device, at least one second state of charge analyser for determining the state of charge of the at least one second thermal energy storage device, and a controller configured to control the at least one heat pump, the at least one first thermal energy storage device, the at least one second thermal energy storage device, and the at least one renewable energy generation device. The controller is configured to control, in dependence on at least the state of charge of the at least one first thermal energy storage device and/or the state of charge of the at least one second thermal energy storage device, whether one of and which of the at least one first thermal energy storage device and the at least one second thermal energy storage device is charged with energy provided by (a heat pump operation of) the at least one heat pump and/or energy provided by the at least one renewable energy generation device. Furthermore, the present invention relates to a method of using the energy management system.