Navarra Frozen Vegetables Company's full-process intelligent cold storage

Customer name:

Cristina Figuero (Operations Director)
Company name:

Navarra Frozen Vegetables Company
Project location:

An industrial area on the banks of the Ebro River, Arguedas, Navarra, Spain
Cold storage type:

-20℃ freezer (long-term storage of vegetables) + 0~4℃ pre-cooling room
Project period:

September 2021 - April 2022 (7 months)

Project Background and Core Challenges

Pain points of existing facilities

Low efficiency of manual forklift operation:

Only 8 pallets can be processed per hour at -20℃, and frequent rotation of workers leads to the risk of cold chain breakage;
Insufficient space utilization:

Traditional shelf warehouses can only store 3,500 tons of vegetables, which cannot meet the annual production demand of 28,000 tons;
High cargo damage rate:

Manual handling causes annual losses of more than 3% (mainly in fragile products such as blueberries and asparagus).

Technology upgrade requirements

Require full automation of handling, eliminating manual low-temperature operations;
Storage capacity increased to 9,000 pallets (single pallet bearing 1 ton), supporting 1,000+ SKU fine management;
Temperature control accuracy of ±0.5℃, ensuring compliance with the EU frozen food standard EN12830.

Highlights of the overall technical solution

Intelligent logistics system

Dolphin Star AE1516 robot cluster:

Deploy 12 AE1516 unmanned forklifts, which are equipped with low-temperature enhanced SLAM navigation (stable operation in the environment of -30℃), with the positioning accuracy of ±5mm;

Dynamic path optimization: Four-wheel take-up in a 1.8m narrow lane, solving the channel blocking problem caused by the non-removable limit block;

Automatic charging without tasks: The temperature of the charging pile area is maintained at 10℃, and the battery life, increased by 30%.
Integrated warehouse rack structure:

33-meter-high steel structure shelf (bearing 1.5 tons/pallet), integrated 4-aisle stacker, with the storage and retrieval efficiency of 50 pallets/hour;

Insulation layer innovation: 120mm polyurethane warehouse board (density: 38kg/m³), embedded with moisture-proof resin film, with the cold bridge heat flow value ≤0.02W/m·K.

Refrigeration and energy efficiency system

Ammonia/CO₂ cascade refrigeration:

Main unit: BITZER ECOLINE variable frequency screw machine (380V/3 phase), with COP value reaching 1.8 at -40℃ evaporation temperature;

Hot gas defrosting technology: Evaporator defrosting cycle is shortened to 22 minutes/time, and energy consumption is reduced by 35%.
Internet of Things temperature control network:

120 NB-IoT temperature and humidity sensors are deployed in the warehouse, and data is uploaded to the WMS system in real time;

Emergency plan: When the ammonia leakage concentration is greater than 10%LEL, the top spray + explosion-proof fan will start within 30 seconds.

Implement key nodes in stages

Phase 1: Renovation of old warehouses and strengthening of foundations

Geological reinforcement: Bored piles penetrate 8m into the sandstone layer (bearing capacity: 12kN/m²), and PE moisture-proof film + heating ventilation pipes (to prevent frost heave) are laid on the ground;
Remove old shelves: Laser cutting is used to avoid sparks, and dust concentration monitoring is maintained below 5mg/m³.

Phase 2: Integration of warehouse and intelligent equipment

Robot path preview: Simulate AE1516 running trajectory through digital twin platform, optimizing the positioning accuracy of pickup point;
Special treatment for air tightness: Pre-compression of door frame sealing strip reaches 12N/cm (50% higher than national standard), and cold leakage of door gap is maintained below 3W/m².

Phase 3: Multi-system joint debugging

Pressure test: Refrigeration pipeline maintains at 4.0MPa for 48 hours (pressure rise ≤0.3kPa);
Temperature field uniformity verification: Empty warehouse operates at -25℃ for 72 hours, with a maximum temperature difference of 1.7℃ at 9 temperature measurement points (standard requirement ≤2℃).

Project results and quantitative value