Thermal Storage Heat Exchanger with Automatic Ice Removal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Thermal storage tanks face issues with solid phase material formation due to water expansion, leading to reduced performance, measurement difficulties, and potential damage, requiring additional heaters and complex control systems for ice removal.

Innovation Solution

A thermally actuated valve system directs warm process fluid through additional heat exchange tubing to automatically melt ice in undesirable areas, bypassing solid phase formation without additional devices or controls, allowing the heat exchanger to operate in freezing and thawing modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional heaters are used to remove ice, then ice removal capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improveice removal capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses the existing heat exchanger to melt ice automatically by redirecting warm process fluid through the solid phase removal flow path when ice is detected, eliminating the need for separate heaters and control systems. The heat exchanger serves dual purposes: freezing thermal storage material and removing solid phase formations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The heat exchanger is designed to perform multiple functions: freezing thermal storage material during normal operation and melting ice formations when needed. By integrating the solid phase removal capability into the existing heat exchanger, the system avoids adding separate ice removal devices.

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

2Quantity of substance

If water freezes and expands, then thermal energy storage is improved, but solid phase formation in undesirable areas increases

Engineering Contradiction:
Improvethermal energy storage capacityVSAvoidsolid phase formation in undesirable areas
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The solid phase removal flow path extracts warm process fluid from the main heat exchange flow path and directs it through additional tubing positioned in areas prone to ice formation. This removes the harmful solid phase formations from undesirable areas while preserving the beneficial freezing process in the thermal storage material.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The solid phase removal flow path acts as an intermediary system that uses warm process fluid to melt ice formations in undesirable areas. The additional heat exchange tubing serves as a mediator between the warm process fluid and the solid phase material, enabling targeted ice removal without affecting the main thermal storage process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Extent of automation

If a thermally actuated valve is used to direct process fluid, then automatic ice removal is achieved, but device complexity increases

Engineering Contradiction:
Improveautomatic ice removal operationVSAvoidvalve control mechanism
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The thermally actuated valve automatically redirects process fluid based on temperature conditions without requiring external control systems. When the process fluid temperature indicates ice formation conditions, the valve self-actuates to divert warm fluid through the solid phase removal path, achieving automatic operation with minimal added complexity.

Inventive Principle:
Principle #25Self-service

4Reliability

If process fluid is directed through additional heat exchange tubing, then ice melting capability is improved, but loss of time in flow path increases

Engineering Contradiction:
Improveice melting capabilityVSAvoidprocess fluid circulation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The solid phase removal flow path uses only a portion of the process fluid flow to melt ice formations, while the majority of the flow continues through the main heat exchange path. This partial action approach provides sufficient ice melting capability without significantly increasing the overall circulation time of the process fluid.

Inventive Principle:
Principle #16Partial or excessive action

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 solution enables automatic, temperature-based operation for ice removal, maintaining system performance and preventing damage by directing process fluid through solid phase removal paths, thus eliminating the need for separate ice removal devices and controls.

Implementation Method 1

directing a flow of the process fluid into the heat exchange flow path... such that the process fluid absorbs energy from the thermal storage material

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

Phase change can be an efficient method for thermal storage in a thermal storage tank due to the relatively large latent heat of phase changes

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

The use of a thermally actuated valve to direct warm process fluid through additional heat exchange tubing in the areas to remove such ice

Methodology Applied
Scientific EffectThermal actuation: Thermal Expansion

Implementation Method 4

a heat exchanger includes one or more tubes defining a heat exchange flow path extending from an inlet to an outlet

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4071434B1Systems and methods for thermal storage solid phase formation removal
Publication Date: 2024.09.18 TRANE INTERNATIONAL INC
  • EP4071434B1 patent drawingFigure 1
  • EP4071434B1 patent drawingFigure 2
  • EP4071434B1 patent drawingFigure 3

AI summary

Heat exchangers for thermal storage systems include a valve that can direct process fluid passing through the heat exchanger through supplemental heat exchanger tubing based on a temperature of the process fluid. The supplemental heat exchanger tubing can be located in areas where ice formation can occur during freezing of the storage fluid of the thermal storage system, but apart from the standard flow path for the heat exchanger. The valve can be a thermally-actuated valve. The thermally actuated valve can be set to divert flow of the process fluid to the supplemental tubing when the process fluid is at or above a melting temperature of the storage fluid. Methods can include selectively flowing process fluid through supplemental heat exchange tubing when it is at a temperature greater than the melting point of a storage material.