Cold Storage Refrigeration System
1. Product Overview
1.1 General Description
A cold storage refrigeration system is a complete package that provides cooling capacity for a cold room, comprising the condensing unit, evaporators (unit coolers or pipe grids), control system and piping. By temperature, cold stores fall into fresh-keeping rooms (0~5℃), chilled rooms (-18~-5℃) and quick-freezing rooms (-30~-18℃). The system operates on a vapour-compression cycle: the compressor raises the refrigerant pressure, the condenser liquefies it, and after throttling by the expansion valve it evaporates in the evaporator, absorbing heat to maintain the low room temperature. Large cold stores use parallel compressor racks that automatically adjust cooling capacity to load changes, achieving significant energy savings.
1.2 Key Features
- Multiple temperature zones: fresh-keeping / chilled / quick-freezing
- Unit cooler or pipe-grid evaporator options
- Single or parallel compressor rack options
- Automatic defrost system
- Precise room temperature control ±1℃
- Remote monitoring and alarm functions
- Automatic energy-saving operation
- Complete defrost and drainage system
1.3 Document Scope
This specification covers the design principles, performance parameters, system classification, key component selection, application fields, design standards and certifications, custom optional configurations, warranty terms, packaging and delivery of the cold storage refrigeration system, together with the information required for an inquiry. It serves as a comprehensive reference for procurement, model selection and technical communication.
2. Working Principle
2.1 Cold Storage System Process Flow
Cold storage system working cycle: compressor running → refrigerant circulating → evaporator absorbing heat to maintain room temperature → condenser rejecting heat → expansion valve throttling → the cycle repeats. Room temperature sensors monitor the temperature in real time: when it rises above the setpoint the compressor starts cooling, and when it falls below, the unit stops to save energy. Frost on the evaporator surface impairs heat transfer and must be removed periodically (hot-gas or electric defrost). Door opening causes cooling losses, so air curtains and rapid doors are fitted to minimise them.
3. System Classification
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| Fresh-keeping room | 0~5℃ | Fruit/vegetable and pharmaceutical storage | Unit cooler evaporation | Single compressor |
| Chilled room | -18~-5℃ | Frozen goods / meat storage | Unit cooler / pipe grid | Single / parallel compressors |
| Quick-freezing room | -30~-18℃ | Food quick-freezing | Unit cooler | Parallel compressors |
| Ultra-low-temperature room | -60~-30℃ | Special item storage | Pipe-grid evaporation | Cascade refrigeration |
4. Technical Parameters
4.1 Main Technical Parameters of the Cold Storage Refrigeration System
| Small fresh-keeping store | Medium chilled store | Large chilled store | Quick-freezing store |
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| Store volume (m³) | 50-100 | 200-500 | 1000-5000 | 100-500 |
| Room temp. range (℃) | 0~5 | -18~-5 | -18~-5 | -30~-18 |
| Compressor power (kW) | 3-7.5 | 7.5-22 | 22-75 | 15-45 |
| Evaporator type | Unit cooler | Unit cooler / pipe grid | Unit cooler + pipe grid | Unit cooler |
| Refrigerant | R22/R404A | R22/R404A | R404A/NH3 | R404A |
| Defrost method | Electric | Hot-gas / electric | Hot-gas | Hot-gas |
| Daily power consumption (kWh) | 15-40 | 40-120 | 120-500 | 80-200 |
4.2 Dimensions and Weight
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| Small fresh-keeping store (50m³) | Unit: 1.5×0.8×1.2m | Unit coolers: 2 | Piping: 50m | - | |
| Medium chilled store (300m³) | Unit: 2×1.2×1.8m | Unit coolers: 4 | Piping: 150m | - | |
| Large chilled store (2000m³) | Parallel rack: 4×2×2.5m | Unit coolers: 12 | Piping: 600m | - | |
| Quick-freezing store (200m³) | Unit: 2.5×1.5×2m | Unit coolers: 6 | Piping: 200m | - | |
5. Applications
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| Food | Fresh-keeping / chilled meat / quick-freezing | Food grade | Cold-chain logistics |
| Pharmaceutical | Drug / vaccine / blood storage | GSP compliance | Pharmaceutical cold stores |
| Chemical | Low-temperature storage of chemical raw materials | Explosion-proof optional | Chemical cold storage |
| Agricultural produce | Fruit/vegetable fresh-keeping / seed storage | Temperature and humidity control | Controlled-atmosphere cold store |
| Logistics | Cold-chain warehousing and distribution | Multi-temperature zones | Distribution centre cold store |
6. Core Component Selection
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| Compressor rack | Compresses the refrigerant | Reciprocating / screw / parallel | Brand determines reliability |
| Condenser | Rejects heat on condensation | Air / water / evaporative cooled | Selected according to the environment |
| Evaporator (unit cooler) | Absorbs heat and cools the room | Copper tubes, aluminium fins + fans | High air volume, long throw |
| Expansion valve | Throttles and reduces pressure | Thermostatic / electronic | Electronic valves give more accurate control |
| Control system | Coordinates operation | PLC + touch screen | Includes temperature logging and alarms |
| Defrost system | Removes frost from the evaporator | Hot-gas / electric / water defrost | Hot-gas defrost is the most efficient |
| Piping | Connects all components | Copper / stainless steel pipe | Insulation treatment required |
| Room insulation | Thermal insulation | Polyurethane insulation panels | Thickness 100-200mm |
7. Design Standards and Certifications
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| Relevant GB/T standards | Design and manufacture | Fully compliant | Type test report |
| GMP (cGMP) | Design, manufacture, documentation | Fully compliant | GMP compliance certificate |
| ISO 9001:2015 | Quality management system | Certified | ISO 9001 certificate |
| CE certification | Machinery safety / EMC | Optional | CE declaration of conformity |
| FDA | Food / pharmaceutical grade | Optional | FDA compliance documents |
8. Custom Optional Configurations
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| 1 | Room temperature zone | Fresh / chilled / quick-freeze / ultra-low | Fresh-keeping | Selected as required |
| 2 | Evaporator | Unit cooler / pipe grid / combined | Unit cooler | Pipe grid +1-2 weeks |
| 3 | Compressor | Single / parallel / inverter | Single | Parallel +2-3 weeks |
| 4 | Refrigerant | R22/R404A/NH3 | R22 | NH3 +3 weeks |
| 5 | Defrost method | Electric / hot-gas / water | Electric | Hot-gas +1 week |
| 6 | Control system | Standard / remote monitoring / GSP verification | Standard | GSP +2-3 weeks |
9. Material Property Requirements
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| Operating temperature | -40~250℃ | Depends on seals and materials |
| Corrosivity | Mild to moderate corrosion | Strong corrosion requires 316L or a lining |
| Explosion-proof requirement | Selected according to the site | Zone 1 / Zone 2 differ in grade |
10. Warranty Terms
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| Main equipment warranty | 12 months | All components included | 12 months from successful commissioning |
| Extended warranty (optional) | 24 months | Same as standard warranty | Must be purchased with the order |
| Wear-parts warranty | 6 months | Seals, bearings, etc. | Normal wear excluded |
11. Packaging and Delivery
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| Standard lead time | 6-10 weeks after order confirmation |
| Custom configuration lead time | 10-16 weeks |
| Incoterms | FOB Shanghai / CIF / DAP |
| Packaging | Export wooden case |
| Shipping | Container or break-bulk vessel |
12. Information Required for Inquiry
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| 1 | Cold store purpose | Fresh-keeping / chilled / quick-freezing |
| 2 | Volume required | m³ or m² |
| 3 | Room temperature requirement | ℃ |
| 4 | Goods to be stored | Food / pharmaceuticals / chemicals |
| 5 | Ambient temperature | Summer maximum in ℃ |
| 6 | Power supply specification | V/Hz/phases |
| 7 | GSP verification required | Yes / no |
| 8 | Installation conditions | Floor / space |