Songzi Xinglu Logistics Co., Limited

Project Name: New Cold Chain Logistics Cold Storage Project of Songzi Xinglu Logistics Co., Ltd.

Project Location: South Side of Jinshan Avenue, Xiliu Village, Xinjiangkou Subdistrict, Songzi City

Cold Storage Installation Contractor: Senbin Holdings

Cold Storage Type: Large-scale Cold Chain Logistics Cold Storage, Freezer, Dual-temperature Cold Storage, Quick-freezing Warehouse

I. Project Scale and Location Advantages

According to public project documents, the total investment of the Xinglu Logistics Park reaches 220 million RMB, covering a land area of approximately 97.8 mu. The park plans to construct one 6-storey office building and four warehouses equipped with complete cold storage facilities, with a total warehouse capacity of 70,000 tons.

Located on the south side of Jinshan Avenue, Xinjiangkou Subdistrict, Songzi City, the project is 70 kilometres away from the Three Gorges Airport, 11 kilometres from Songzi Railway Station on the Wuhan-Yichang High-speed Railway and Jiaozuo-Liuzhou Railway, and 14 kilometres from Songzi Port in Lingang New Area, enjoying convenient combined transportation of highway, railway and waterway.

The cold storage facilities include a roughly 3,300 m² freezer (-15℃ ~ -22℃), a roughly 3,300 m² dual-temperature cold storage (-22℃ ~ +5℃), and a 102 m² quick-freezing warehouse (-25℃ ~ -35℃). Three temperature zones coexist, with a temperature span of up to 40℃.

II. Technical Difficulties of Cold Storage Works

Compared with previous projects, this project features the largest number of temperature zones and the widest temperature span, bringing three major technical challenges.

First, the coexistence of three temperature zones leads to high system complexity. Most previous projects adopted a single temperature zone or dual temperature zones with a temperature span no more than 20℃. This project integrates three independent temperature zones: deep cold quick-freezing at -35℃, medium-temperature freezing ranging from -22℃ to -18℃, and the dual-temperature warehouse covering a wide temperature range of -22℃ to +5℃ with a temperature difference of 27℃.

Refrigeration systems for the three temperature zones shall be configured separately, and refrigeration pipelines shall be laid in zones. The thickness of insulation panels shall be selected by temperature zone: panels for quick-freezing warehouses ≥ 200 mm, panels for freezers ≥ 150 mm, and panels for the refrigerated section of dual-temperature warehouses ≥ 100 mm.

Second, the dual-temperature cold storage (-22℃ ~ +5℃) poses the biggest technical challenge. Within one warehouse, separate areas need to maintain freezing and refrigerating temperatures respectively, realised via partition walls and independent evaporators. The temperature difference between the two sides of the partition wall can reach 27℃, imposing stringent requirements on thermal insulation joint treatment. Panel joints, sealed sections of pipelines passing through walls and door openings are high-risk areas for thermal bridges. Improper treatment will cause condensation and cold loss.

Third, diversified stored goods. Documents show that the cold storage will accommodate primary agricultural products (vegetables, fruits, meat, poultry, eggs, aquatic products), processed food (quick-frozen food, cooked food, ice cream, dairy products), building materials, pharmaceuticals and other commodities. Different categories have vastly different requirements for temperature and humidity: ice cream requires constant temperature below -22℃ with temperature fluctuation ≤±1℃; vegetable preservation demands relative humidity between 85% and 95%; cement, coatings and other building materials must be stored separately from food products in independent zones.

III. Installation Solution by Senbin Holdings

Senbin defines functional zones for the four warehouses: one warehouse for quick-freezing and freezing (combination of deep cold and medium temperature), one for dual-temperature cold storage (-22℃ ~ +5℃ wide temperature range), and the remaining two as ordinary warehouses for building materials and packaging materials. Cold chain systems are centrally arranged in the first two warehouses, with strict physical isolation between normal-temperature goods and cold chain goods.

Segmented Installation for Three Temperature Zones

The 3,300 m² freezer, 3,300 m² dual-temperature cold storage and 102 m² quick-freezing warehouse form independent installation sections assigned to separate construction teams working simultaneously. Each section is equipped with independent compressors, evaporators and control systems for independent commissioning without mutual interference.

The construction sequence prioritises the quick-freezing warehouse (deep cold system requires the longest commissioning cycle), followed by the freezer and finally the dual-temperature cold storage. The overall construction period is controlled within 80 days.

Specialised Treatment for Partition Wall Joints of Dual-temperature Cold Storage

The partition wall separating the -22℃ zone and +5℃ zone adopts double-sided colour steel polyurethane sandwich panels with a thickness of 200 mm. Steel connectors are installed at panel joints to guarantee structural strength. Flexible thermal insulation sleeves are fitted for pipelines passing through walls, and the gaps between sleeves and pipelines are fully filled with polyurethane foam. Independent evaporators and temperature sensors are deployed on each side of the partition wall for separate temperature control.

High-speed rolling shutters and air curtains are installed at door openings with opening duration limited to ≤5 seconds to minimise cold exchange.

Installation Standards for Quick-freezing Warehouse (-35℃)

Deoxidised copper tubes are adopted for refrigeration pipelines. All welding operations are carried out under nitrogen protection, and no less than 20% of welding joints shall be inspected by radiographic testing. Before refrigerant filling, the system shall be evacuated to below 50 Pa with water content controlled within 15 ppm.

Construction Arrangement for Adverse Weather

The construction period coincides with the rainy season in Songzi (May to September) with concentrated rainfall. Mobile rain shelters are erected for outdoor panel hoisting and pipeline welding; construction pauses when it rains and resumes once the weather clears. During high-temperature periods (≥35℃), work schedules are adjusted: outdoor construction is arranged in the morning and evening, while indoor prefabrication work is conducted at noon.

IV. Handover and Market Prospects

Upon completion, the project’s cold chain logistics services cover storage and distribution of special commodities including primary agricultural products, processed food, fast food raw materials and pharmaceuticals.

After equipment installation, three sets of systems will undergo full-load cooling tests sequentially: the quick-freezing warehouse reaches -35℃ within 7 hours with temperature fluctuation controlled within ±1.0℃ under full load; the freezer maintains stable temperature at -22℃; the freezing and refrigerating sections of the dual-temperature cold storage both meet design standards, and no condensation occurs on the partition wall under a 27℃ temperature difference between the two sides. The project passed acceptance on schedule.

This project verifies Senbin’s capability in system integration under complex working conditions including coexisting multi-temperature zones, thermal insulation of partition walls with wide temperature differences, and separate storage of food and building materials. It serves as a complete engineering reference for multi-category agricultural and sideline product logistics cold storage projects.