Hydronic Expansion Tank Valve Control for Freeze Protection

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Solution Overview

Problem

Existing refrigeration systems with hydronic kits face increased costs and efficiency losses due to the need for additional materials like insulation and electrical heaters to prevent freezing in expansion tanks, which are not effectively addressed.

Innovation Solution

A compliant containment device with a thermostatic valve and insulation material within or around it, which operates based on temperature data to prevent freezing without the need for separate heaters, ensuring fluid flow and maintaining system efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulation and electrical heaters are added to the expansion tank to prevent freezing, then the freezing protection is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvefreezing protectionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses the chiller's own operational characteristics to prevent freezing. When the chiller is running, cold water flows through the expansion tank, preventing freezing. The control system monitors chiller operation status and activates circulation only when needed, making the system self-regulating without external heaters or complex insulation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The expansion tank serves dual purposes: it functions as both an expansion tank for pressure regulation and as a freezing protection zone. By routing cold water through the expansion tank during chiller operation, the system uses the same fluid circulation for both pressure management and temperature maintenance, eliminating the need for separate heating systems.

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

2Reliability

If insulation and electrical heaters are added to the expansion tank to prevent freezing, then the freezing protection is improved, but the material and assembly costs increase

Engineering Contradiction:
Improvefreezing protectionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system leverages the chiller's operational cycle to provide freezing protection. During normal operation, cold water circulation through the expansion tank prevents freezing. The control system automatically manages this circulation based on chiller status, eliminating the need for expensive insulation materials and electrical heating components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses the temporarily cold water from the chiller operation as a protective agent. This cold water, which would otherwise be wasted, is routed through the expansion tank to prevent freezing. This approach replaces expensive permanent insulation and heating systems with a temporary, already-present cooling resource.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If a thermostatic valve and solenoid are added to control temperature, then the temperature control precision is improved, but the device complexity increases

Engineering Contradiction:
Improvetemperature control precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system incorporates a temperature sensor that continuously monitors the expansion tank temperature and provides feedback to the control system. The controller adjusts the solenoid valve operation based on this feedback, maintaining precise temperature control while using simple on/off valve actuation rather than complex continuous modulation systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The solenoid valve acts as an intermediary between the control system and the water flow. It translates electrical control signals into mechanical flow control, providing precise temperature management through a simple binary open/closed state rather than requiring complex continuous control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution effectively prevents freezing in refrigeration systems, reducing material and assembly costs while maintaining system efficiency by using a thermostatic valve and insulation to manage temperature and fluid flow.

Implementation Method 1

the compliant containment device further includes an insulation material disposed in a location including at least one of within and around the compliant containment device

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

the valve includes a thermostatic valve

Methodology Applied
Scientific EffectThermostatic expansion: Thermal Expansion

Implementation Method 3

a solenoid operably coupled to the temperature sensing device and the valve, wherein the solenoid is configure to operate the valve based in part on the temperature data

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnet

Data Source

PatentEP3440411B1Air cooled chiller hydronic kit
Publication Date: 2024.08.14 CARRIER CORP
  • EP3440411B1 patent drawingFigure 1~2
  • EP3440411B1 patent drawingFigure 3

AI summary

A compliant containment device for use in a hydronic system, the compliant containment device including a vessel including an inlet and an outlet, and valve operably coupled to at least one of the inlet and outlet, wherein the valve is configured to operate between an open and closed position based in part on a temperature.