Optimized steam boiler for soil steam disinfection: Structural design, CFD simulation, and field application

Area of Science:

• Agricultural Engineering
• Thermal Fluid Systems
• Sustainable Agriculture

Background:

• Soil-borne pathogens and continuous cropping hinder facility agriculture.
• Existing steam disinfection systems are immobile and inefficient.
• Lack of mobile steam generation limits chemical-free soil pathogen control.

Purpose of the Study:

• Develop a mobile and efficient gasoline-powered steam boiler for facility agriculture.
• Optimize a Helmholtz-type pulse combustion system for compactness and thermal efficiency.
• Validate the system's efficacy in soil steam disinfection.

Main Methods:

• Designed and optimized a gasoline-powered steam boiler with a Helmholtz-type pulse combustion system.
• Utilized computational fluid dynamics (CFD) to optimize combustor layout.
• Conducted field validation using a double-layer steam injection needle for improved thermal retention.

Main Results:

• Achieved a 67.11% reduction in boiler length and a 204% increase in heat transfer area.
• Optimized combustor configuration reduced water heating time by 15.52 seconds.
• Maintained soil temperatures ≥80°C for 63.84 minutes, extending thermal retention by 27.02%.

Conclusions:

• The developed gasoline-powered steam boiler provides a practical mobile solution for soil steam disinfection.
• The system effectively delivers lethal thermal dosage to soil pathogens, addressing continuous cropping issues.
• Advances fundamental insights into efficient thermal fluid system design for agricultural applications.