Hydraulic Interconnection for Thermal Networks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional systems fail to effectively integrate district thermal energy distribution networks with local thermal energy networks, particularly in terms of temperature differences and heat transfer fluid variations, leading to inefficiencies and resilience issues in low-temperature remote thermal energy distribution networks when connected with heat pumps.

Innovation Solution

A hydraulic interconnection system that includes a heat exchanger, mixing valves, and pumps to manage heat transfer fluid flow between high-temperature and low-temperature networks, allowing for efficient and resilient integration of heat pumps with low-temperature remote thermal energy distribution networks, including a method for operating modes that adjust flow rates and valve positions to maintain desired temperatures and optimize energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a series circuit configuration is used to connect heat pumps to the thermal network, then the system structure is simple, but the last installations receive less heat and pumping requirements are significant

Engineering Contradiction:
Improvesystem structureVSAvoidheat delivery to last installations
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the thermal network into multiple parallel circuits (primary circuit connected to the thermal network and secondary circuits connected to individual heat pumps). This segmentation allows each heat pump to receive adequate heat independently while reducing the cumulative pressure losses that plague series configurations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate components including a heat exchanger that couples the primary and secondary circuits, mixing valves that blend heat transfer fluids from different temperature zones, and circulation pumps that maintain proper flow rates. These intermediaries enable efficient heat transfer while maintaining system reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If series connection with bypass valve is used, then heat energy transfer to final customers is improved, but network pressure losses and equipment cost remain significant

Engineering Contradiction:
Improveheat energy transferVSAvoidnetwork pressure losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent employs dynamically controllable mixing valves and circulation pumps that adjust their operation based on real-time temperature and flow requirements. This dynamic control optimizes heat transfer efficiency while minimizing pressure losses and energy consumption in the network.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes key operating parameters including heat transfer fluid temperature (using different temperature zones in primary and secondary circuits), flow rates (controlled by circulation pumps), and valve positions (mixing valves) to optimize both heat transfer and minimize pressure losses.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If conventional hydraulic connection is used, then integration of district heating networks is achieved, but temperature differences and variations in heat transfer fluid flows are not efficiently managed

Engineering Contradiction:
Improveintegration capabilityVSAvoidefficiency of heat transfer
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent creates a universal hydraulic connection system that can efficiently integrate district heating networks with various types of local thermal networks and heat pump configurations. The modular design with standardized primary and secondary circuits can adapt to different building requirements and network conditions.

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

Solution Approach 2:

The system incorporates feedback control through mixing valves and circulation pumps that respond to temperature differences and flow variations in real-time. This feedback mechanism maintains optimal heat transfer efficiency by adjusting operating parameters based on actual network conditions.

Inventive Principle:
Principle #23Feedback

4Use of energy by moving object

If ground loop temperatures are allowed to drop too low, then energy efficiency may improve, but subsurface freezing occurs which negatively impacts network resilience

Engineering Contradiction:
Improveenergy efficiencyVSAvoidnetwork resilience
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent carefully controls the temperature parameter of the heat transfer fluid in the ground loops by using appropriately designed heat exchangers and mixing valves. This ensures temperatures remain low enough for energy efficiency but above freezing to prevent subsurface ice formation that would damage the network.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system incorporates protective measures in advance by designing the hydraulic connection to maintain minimum temperature thresholds in ground loops. The mixing valves and control systems are configured to prevent temperatures from dropping into the freezing range, cushioning against the harmful effects of subsurface freezing before they can occur.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 system enhances the efficiency and resilience of thermal energy distribution networks by optimizing heat transfer and maintaining stable temperatures, reducing energy losses and equipment costs, while ensuring the network's operational integrity, especially in conditions where temperatures may drop below freezing.

Implementation Method 1

a heat exchanger (7), a high-temperature connection circuit (16) passing through the heat exchanger (7)

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

a first mixing valve (V1) interconnecting the inlet (34a) of the low temperature connection circuit (18) to the inlet (32a) of the high temperature connection circuit (16)

Methodology Applied
Scientific EffectFluid mixing:

Implementation Method 3

a heat pump (5), a heat pump connection circuit (22) comprising an evaporator circuit (22a) with an inlet (28a) and an outlet (28b) and a condenser circuit (22b) with an inlet (30a) and an outlet (30b)

Methodology Applied
Scientific EffectHeat pump cycle: Heat Exchanger

Implementation Method 4

the evaporator circuit (22a) includes a pump (P1) installed in the hydraulic interconnection unit (8) for the circulation of the heat transfer fluid

Methodology Applied
Scientific EffectFluid circulation: Pump

Data Source

PatentEP3969819B1Hydraulic interconnection system for thermal network
Publication Date: 2023.06.07 APTERIX SA
  • EP3969819B1 patent drawingFigure 1
  • EP3969819B1 patent drawingFigure 1a
  • EP3969819B1 patent drawingFigure 2a

AI summary

Hydraulic interconnection unit (8) for a thermal energy distribution system (1) of a building connected to a low-temperature thermal energy (2) ("single-pipe energy network") remote distribution network, the building comprising a high-temperature thermal energy distribution network (3) ("HV network"), a building hot-water network (4) and a heat pump (5). The hydraulic interconnection unit comprises: - a heat exchanger (14); - a high-temperature connection circuit (16) passing through the heat exchanger (14) and comprising an inlet (32a) and an outlet (32b); - a low-temperature connection circuit (18) comprising an inlet (34a) and an outlet (34b), - a heating connection circuit (20) comprising an inlet (36a) and an outlet (36b), and - a heat pump connection circuit (22) comprising an evaporator circuit (22a) with an inlet (28a) and an outlet (28b) and a condenser circuit (22b) with an inlet (30a) and an outlet (30b), the inlet (36a) of the heating connection circuit being connected to the outlet (30b) of the condenser circuit of the heat pump connection circuit (22), the inlet (28a) of the evaporator circuit (22a) being connected to the outlet (34b) of the low-temperature connection circuit (18). The hydraulic interconnection unit further comprises: - a first mixing valve (V1) interconnecting the inlet (34a) of the low-temperature connection circuit (18) to the inlet (32a) of the high-temperature connection circuit (16) and to the outlet (28b) of the evaporator circuit (22a) so as to be able to inject heat transfer fluid coming from the low-temperature connection circuit (18) into the high-temperature connection circuit (16), and - a second mixing valve (V2) interconnecting the inlet (36a) of the heating connection circuit (20), via a bypass (38) passing through the heat exchanger (14), and the inlet (30a) of the condenser circuit (22b), to the outlet (36b) of the heating connection circuit (20) such that it is possible for the heat transfer fluid passing through the heat exchanger (14) to be injected with the heat transfer fluid returning from the condenser circuit (22b).