Introduction: As the leader of modern industry, thermal equipment is everywhere in the petrochemical industry. In the context of the country's increasing emphasis on energy conservation, energy conservation of thermal equipment has become one of the important links in the energy conservation work of petrochemical enterprises. In order to ensure the safe operation of thermal equipment and reduce heat loss, and to achieve the purpose of saving energy and reducing product costs, it is necessary to insulate the thermal equipment according to different requirements and specifications. To this end, through long-term research and exploration, a new type of thermal insulation and energy-saving material, a ceramic fiber aluminum foil blanket (abbreviated as aluminum foil blanket), has been developed and developed, and has been put into large-scale production. This material is a combination product that uses special equipment and special adhesives to integrate ceramic fiber blankets and metal aluminum foil into an integrated structure. It has the characteristics of light weight, good thermal insulation effect, high density, corrosion resistance, good thermal shock resistance, high longitudinal and transverse tensile strength, and convenient construction and maintenance. It is particularly suitable for the insulation and heat preservation of high-temperature thermal equipment and heating pipes with demanding thermal insulation and energy-saving effects.
1. Current status and challenges of thermal insulation of petrochemical industry thermal equipment
Petrochemical industry is a national basic energy industry, and its production process involves a large number of high-temperature thermal equipment. According to statistics, heat loss in typical petrochemical enterprises accounts for about 15-25% of total energy consumption, of which heat loss through the surface of equipment is as high as 30-40%. Traditional insulation materials such as rock wool and calcium silicate have the following limitations:
Thermal conductivity is relatively high (0.040-0.060W/m·K)
Poor thermal shock resistance (easy to crack when temperature difference>200℃)
Short service life (need to be replaced every 3-5 years on average)
Under the background of the national "dual carbon" strategy, the new version of the "Technical Specifications for Energy Conservation Supervision in the Petrochemical Industry" in 2023 requires that the surface temperature of thermal equipment shall not exceed the ambient temperature +25℃, which puts higher requirements on insulation materials.
2. Technological innovation of aluminum foil-coated ceramic fiber blanket
2.1 Material structure and production process
The aluminum foil-coated ceramic fiber blanket adopts a three-layer composite structure:
Substrate layer: high-purity ceramic fiber needle-punched blanket (Al₂O₃≥45%)
Fiber diameter: 5-7μm (spinning process)
Porosity: 93±2%
Tensile strength: longitudinal ≥80kPa, transverse ≥60kPa
Adhesive layer: high-temperature resistant inorganic adhesive
Working temperature: -50～1200℃
Bond strength: ≥0.15MPa
Functional layer: high-purity aluminum foil (purity ≥99.5%)
Thickness selection: 0.047mm (standard type), 0.2mm (reinforced type)
Reflectivity: ≥85% (wavelength 2.5-25μm)
The production process adopts continuous hot pressing composite technology to ensure the permanent bonding of aluminum foil and substrate, and the peel strength is ≥1.5N/cm.
2.2 Specification system and selection guide
The width is 300mm, 610mm, 1220mm, the length is 3600mm, 7200mm, the thickness of ceramic fiber blanket is 10mm, 20mm, 30mm, 50mm, the thickness of aluminum foil is 0.047mm, 0.2mm, and the specific size can also be customized according to user requirements.
Selection suggestions:
Pipeline insulation: 10-20mm+0.047mm aluminum foil
Reactor insulation: 30-50mm+0.2mm aluminum foil
High-temperature valve: multi-layer 10mm composite structure
3. Analysis of multi-dimensional thermal insulation mechanism
3.1 Conduction heat dissipation control
Fiber maze effect: disordered ceramic fibers extend the heat flow path by 3-5 times
Point contact heat transfer: fiber-to-fiber contact area <5%, significantly reducing contact heat conduction
Low thermal conductivity characteristics:
Thermal conductivity coefficient at room temperature: 0.035W/m·K
At 800℃: 0.085W/m·K
3.2 Convection heat dissipation suppression
Microporous gas chamber structure: average pore size <50μm, gas mean free path 0.1μm
Dynamic air pressure balance: 0.1-0.3kPa shielding air pressure is formed in the pores
Aluminum foil sealing effect: air permeability <0.5L/m²·s
3.3 Radiative heat dissipation barrier
Dual reflection system:
Ceramic fiber surface reflectivity: 65-70%
Aluminum foil mirror reflectivity: 85-92%
Spectral selectivity: Reflectivity >90% in the 2.5-15μm band
4. Comprehensive benefit evaluation
4.1 Direct economic benefits
Energy saving rate: 25-40% (compared with traditional materials)
Return on investment: 6-18 months
Service life: 8-10 years (extended 2-3 times)
4.2 Indirect benefits
Safety improvement:
Surface temperature reduced by 15-30℃
Fire risk level reduced by 1 level
Space optimization:
Insulation layer thinned by 50-60%
Increase equipment layout flexibility
Environmental protection contribution:
Annual reduction of CO₂ emissions per unit 5000-10000 tons
No asbestos, no VOCs release
5. Technical development direction
Intelligent insulation system:
Integrated temperature sensing optical fiber
Self-adjusting reflectivity coating
Ultra-high temperature type:
Develop 1400℃ grade products
Add ZrO₂ nano coating
Green manufacturing:
Waste recycling rate>90%
Low-temperature curing adhesive
With the implementation of the new energy efficiency standard for the petrochemical industry in 2025, the market size of aluminum foil-coated ceramic fiber blankets is expected to exceed 1.5 billion yuan. It is recommended that enterprises focus on the following when selecting:
Oxidation protection treatment of aluminum foil
High-temperature stability of adhesives
Anti-wind erosion performance of products
Through scientific selection and standardized construction, its energy-saving potential can be maximized to create sustainable value for petrochemical enterprises.
