Double Helical Coil Tube — Phase Change Thermal Energy Storage System (PCTES)

Product Overview

The Double Helical Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd., represents a high-performance heat exchange configuration engineered specifically for Phase Change Thermal Energy Storage (PCTES) systems. This innovative product leverages a dual-helix winding geometry to maximize heat transfer surface area within a compact volumetric envelope, enabling efficient thermal energy absorption, storage, and release through latent heat mechanisms. The coil tube design addresses critical challenges in thermal energy storage systems, including low thermal conductivity of Phase Change Materials (PCMs) and the need for high power density during charge and discharge cycles.

As a precision-engineered component, the Double Helical Coil Tube integrates advanced metallurgical processing with optimized geometric design to deliver superior thermal performance, mechanical durability, and long-term operational reliability in demanding industrial and commercial energy storage applications.

Material & Properties

The coil tube is fabricated from high-grade stainless steel, selected for its exceptional combination of corrosion resistance, thermal stability, and mechanical strength. The primary material grades include:

Mechanical Properties

Corrosion Resistance

Specifications

Parameter Specification
Product Designation Double Helical Coil Tube — PCTES Series
Tube Outer Diameter (OD) 6 mm – 50 mm (customizable)
Wall Thickness 0.5 mm – 3.0 mm
Coil Pitch (Helical Spacing) 8 mm – 50 mm
Coil Length Up to 6,000 mm (continuous)
Winding Configuration Double Helical (Dual-Helix)
Material Grade AISI 316L / 321 / 310S / 304L
Surface Finish 2B / BA (Bright Annealed) / Custom
Maximum Operating Temperature 1100°C (AISI 310S)
Minimum Operating Temperature −196°C
Pressure Rating Up to 1.6 MPa (standard); up to 4.0 MPa (reinforced)
Heat Transfer Coefficient ≥ 2500 W/(m²·K) (enhanced configuration)
Tolerance — OD ±0.10 mm
Tolerance — Wall Thickness ±10%
Delivery Form Coil / Cut-to-Length / Assembled Module
Standard Reference ASTM A213 / A269 / GB/T 12771

Manufacturing Process

The production of the Double Helical Coil Tube follows a rigorously controlled multi-stage manufacturing process to ensure dimensional accuracy, metallurgical integrity, and consistent thermal performance:

  1. Raw Material Selection — Certified stainless steel seamless tubes or precision-welded tubes sourced from approved mills, verified through spectroscopic analysis (OES) and chemical composition testing.
  2. Material Preparation — Tubes are cut to required lengths, end-prepped, and inspected for surface defects using visual and automated optical systems.
  3. Double Helical Forming — Using CNC-controlled coil winding machinery, tubes are precisely formed into dual-helix configurations with controlled pitch, diameter, and spacing. The double-helix geometry is achieved through synchronized dual-axis winding mechanisms.
  4. Post-Forming Heat Treatment — Stress-relief annealing at 1050–1100°C followed by controlled cooling to restore full mechanical properties and eliminate residual stresses induced during cold forming.
  5. Solution Annealing — For austenitic grades, solution treatment is performed to ensure maximum corrosion resistance and uniform microstructure.
  6. Surface Finishing — Electropolishing or mechanical polishing to achieve required surface roughness (Ra ≤ 0.8 μm for critical applications).
  7. Quality Inspection — Comprehensive testing including hydrostatic pressure testing, dimensional verification, ultrasonic testing (UT) for internal defects, and dimensional metrology.
  8. Packaging and Delivery — Protected packaging with moisture barriers, dimensional documentation, and material traceability certificates.

Applications

The Double Helical Coil Tube is specifically designed for and excels in the following application domains:

Performance Advantages in PCTES Systems

The double helical geometry provides approximately 40–60% greater heat transfer surface area compared to conventional single-helix coil designs of equivalent volume. This enhancement translates to reduced charging and discharging times, improved system power density, and more uniform temperature distribution within the PCM volume, thereby minimizing thermal stratification losses and maximizing the effective energy storage capacity.

Quality Certifications

Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring adherence to international standards:

Unique Selling Points