BPXG-1 High-Efficiency Ice Storage Coil Tube (Stainless Steel)
Product Overview
The BPXG-1 High-Efficiency Ice Storage Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd., is a precision-engineered stainless steel coiled tube designed specifically for thermal energy storage (TES) applications. This product serves as the core heat exchange element within ice storage accumulators, enabling efficient off-peak refrigeration energy storage and subsequent discharge to meet peak cooling demands. The coil tube geometry maximizes surface-area-to-volume ratio, facilitating rapid heat transfer between the refrigerant medium and the ice-forming slurry or water within the accumulator vessel.
Derived from extensive research documented in the study "BPXG-1 High-Efficiency Ice Storage Accumulator Research," this product represents an optimized design that balances hydraulic resistance, thermal performance, and mechanical durability for long-term operation in demanding HVAC and industrial cooling environments.
Material & Properties
The coil tube is fabricated from high-grade stainless steel, ensuring superior corrosion resistance, mechanical strength, and thermal conductivity suitable for continuous cycling in aqueous and brine environments.
- Base Material: Austenitic Stainless Steel (304 or 316L grade, per customer specification)
- Corrosion Resistance: Excellent resistance to chloride-induced pitting, general corrosion, and stress corrosion cracking (SCC)
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 20°C, ensuring efficient heat exchange performance
- Mechanical Strength: Tensile strength ≥ 520 MPa; yield strength ≥ 205 MPa
- Operating Temperature Range: −40°C to +200°C
- Hygienic Surface: Electropolished or passivated interior surface with Ra ≤ 0.4 μm for slurry compatibility
- Non-Magnetic Property: Confirmed austenitic microstructure (magnetic permeability < 1.05)
Specifications
| Parameter | Specification |
|---|---|
| Model Designation | BPXG-1 Series |
| Tube Outer Diameter (OD) | 16 mm / 22 mm / 28 mm (standard); custom available |
| Tube Wall Thickness | 1.0 mm – 2.0 mm |
| Coil Diameter | 150 mm – 800 mm (configurable) |
| Coil Length (Developed) | 5 m – 120 m (per unit) |
| Coil Pitch / Spacing | 25 mm – 50 mm (optimized for slurry flow) |
| End Connection Type | Flanged (DN25–DN50), threaded, or welded stub |
| Maximum Operating Pressure | 1.6 MPa (standard); 2.5 MPa (reinforced) |
| Heat Transfer Coefficient | ≥ 800 W/(m²·K) (design value under nominal conditions) |
| Refrigerant Compatibility | Water, ethylene glycol (up to 60%), calcium chloride brine |
| Design Life | ≥ 25 years under normal operating conditions |
| Applicable Standards | GB/T 14976, ASME B31.3, EN 10216-5 |
Manufacturing Process
The BPXG-1 coil tube is produced through a tightly controlled multi-stage manufacturing process to ensure dimensional accuracy, metallurgical integrity, and consistent performance:
- Material Selection & Inspection: Stainless steel seamless tubes are sourced from certified mills with full chemical composition analysis (spectrographic testing) and mechanical property verification.
- Tube Straightening & Dimensional Control: Incoming tubes undergo precision straightening to achieve straightness tolerance ≤ 1 mm/m, ensuring uniform coiling without localized stress concentrations.
- Coil Forming (Cold Bending): Tubes are cold-coiled using CNC-controlled coil winding machines with synchronized bending rollers. The process maintains a minimum bend radius of 3× OD to prevent wall thinning and micro-cracking.
- Heat Treatment (if required): Solution annealing at 1050°C followed by rapid water quenching may be applied to relieve residual bending stresses and restore full austenitic properties.
- Welding & Joining: End connections are fabricated using orbital TIG (Tungsten Inert Gas) welding with argon shielding, ensuring full-penetration welds with no oxidation on the interior surface.
- Surface Treatment: All coils undergo pickling and passivation (acid immersion) or electropolishing to remove welding contaminants and establish a protective chromium oxide layer.
- Pressure Testing & NDT: Each unit is hydrostatically pressure-tested at 1.5× working pressure for a minimum 30-minute hold. Radiographic or ultrasonic testing is performed on critical welds per ASME Section V.
- Final Inspection & Packaging: Completed coil tubes undergo dimensional verification, visual inspection, and are packaged with protective end caps and moisture-absorbing desiccants.
Applications
The BPXG-1 High-Efficiency Ice Storage Coil Tube is engineered for a broad range of thermal energy storage and heat exchange applications:
- Ice Storage Accumulators: Primary application — heat exchange coils within water-ice slurry or encapsulated ice storage tanks for commercial building HVAC systems, enabling peak-shaving and demand management.
- Refrigerated Warehouses: Indirect evaporative cooling systems utilizing stored ice for continuous low-temperature supply.
- Industrial Process Cooling: Batch cooling applications in food processing, pharmaceutical manufacturing, and chemical plants requiring precise temperature control.
- Heat Pump Systems: Integration with ground-source or air-source heat pumps as a thermal buffer for improved system COP (Coefficient of Performance).
- Emergency Backup Cooling: Critical infrastructure (hospitals, data centers) where uninterrupted cooling is essential during grid failures or equipment outages.
- Chilled Water Distribution: Secondary-loop heat exchangers in district cooling networks.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems to ensure product reliability and international market compliance:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing operations
- ISO 14001:2015 — Environmental Management System certification
- GB/T 14976-2012 — Compliance with Chinese national standard for cold-rolled seamless stainless steel tubes
- ASME B31.3 — Process piping design and fabrication compliance
- CE Marking — European Conformity for products exported to the European Economic Area
- Material Traceability: Full heat-lot traceability from mill certificate to finished product, with third-party inspection reports (SGS/BV) available upon request
- Welding Procedure Qualification: WPQ (Welding Procedure Qualification) records maintained per ASME Section IX
Unique Selling Points
- Research-Validated Design: The BPXG-1 design is derived from published academic research on high-efficiency ice storage accumulators, ensuring thermodynamically optimized coil geometry for maximum heat transfer efficiency.
- Customizable Configuration: Coil diameter, pitch, length, and connection types are tailored to specific accumulator vessel dimensions and system design parameters.
- Superior Slurry Compatibility: Electropolished interior surfaces minimize ice crystal adhesion and fouling, reducing pressure drop over the operational life of the system.
- Extended Service Life: 316L-grade stainless steel with full passivation provides resistance to chloride attack in brine environments, significantly outperforming carbon steel alternatives.
- End-to-End Quality Assurance: From raw material certification through final pressure testing, every stage is documented and traceable, providing complete confidence in product integrity.
Note: All specifications listed above represent standard configurations. Custom engineering solutions are available upon submission of detailed system requirements. Contact Wenzhou Jixing Metal Materials Co., Ltd. technical sales team for project-specific quotations and design support.