Air-cooled scroll chiller

I. Unit Introduction

The outdoor rain-proof integrated unit adopts hermetic flexible vortex compressors as core components, with air-cooled fin-type condensers for direct air heat dissipation. Built-in water pumps and water tanks are integrated into the unit. It produces chilled water (liquid) ranging from -120 ℃ to +180 ℃ to supply terminal air-conditioning or process equipment. It is the most common aircooled integrated chiller on the market. As a compact piece of cooling equipment with the simplest installation, it can also operate as a modular unit for multiunit parallel connection.

II. System Composition

1. Main Unit (Installed on Outdoor Roof or Ground)

1. Hermetic Vortex Compressor: Multiple independent vortex heads connected in parallel (2-8 units). Each has an independent refrigerant circuit with stepped capacity regulation. Failure of one compressor will not shut down the whole unit. Featuring simple structure, liquidslugging resistance and low failure rate. Main refrigerants: R22, R410A, R404A.

2. Air-Cooled Fined Type Condenser: Copper tubes with aluminum fins plus top axialflow fans for forcedair heat rejection. No cooling tower, cooling water pump or coolingwater circuit is required.

3. Coil / Plate / Shell and Tube Evaporator: Generates low temperature or ultra-low temperature chilled water.

4. Electronic Expansion Valve, Gas-Liquid Separator, PLC Control, Water-flow Protection, Antifreezing, High-Low Pressure Protection & Overload Protection.

5. Hydraulic module：Built-in water pump and water tank inside the unit.

2. Indoor Side: Only Terminals / Process Equipment Required

The whole system features extremely simplified configuration.

III. Refrigeration Principle

1. The vortex compressor compresses refrigerant into hightemperature and highpressure gas.

2. Top fans deliver forcedair cooling for condensation; gaseous refrigerant liquefies and releases heat.

3. The expansion valve throttles, reducing pressure and temperature.

4. The evaporator absorbs heat from chilled water and delivers chilled water for circulation.

IV. Advantages

1. Extremely simple installation: Only power supply and chilledwater piping connections are needed. No equipment room, no cooling tower and no civilengineering work required. Suitable for oldbuilding renovation; can be placed freely on rooftops.

2. Flexible modular capacity expansion: Each module provides 65 kW / 130 kW cooling capacity. Multiple units can be paralleled. Additional units may be added later for higher cooling demand, and units serve as mutual backups.

3. Low initial cost and low maintenance cost: Vortex compressor parts are highly universal and widely available in the market. Minor faults can be repaired easily onsite.

4. Nearly zero water consumption: Preferred option for waterscarce regions and projects where coolingwater systems cannot be implemented.

5. High startstop reliability for intermittent operation: Suitable for shops and offices operating only during daytime; frequent startstop cycles cause little damage.

V. Disadvantages

1. Higher power consumption at high ambient temperature: Above 35 ℃ in summer, heat dissipation degrades and energy efficiency drops sharply. Full load COP ranges only from 3.0 to 3.8. For 24hour continuous operation, powerconsumption costs are much higher than water-cooled screw type or air bearing chillers.

2. Relatively high outdoor noise: Running rooftop fans generate noise. Noise reduction enclosures are required for installations close to residential buildings.

3. Limited maximum cooling capacity per unit: Singlemodule capacity is small. Largescale buildings covering thousands of square meters may require a dozen units in parallel, resulting in complex piping layouts.

4. Strict antifreezing requirement in winter: Watercontaining chambers inside outdoor main units are exposed. Without antifreeze solution in northern regions, evaporators will crack due to freezing.

5. Mediocre partload energy efficiency: Capacity is adjusted merely by compressor onoff cycling. Less smooth and energysaving compared with variablefrequency screwtype and oilfree centrifugal chillers.

VI. Application Scenarios (Precise Positioning)

1. Smallscale commercial central airconditioning: Shops, standalone office buildings, clinics, kindergartens, small hotels, gyms and clubs.

2. Smallscale industrial cooling: Small injectionmolding machines, machinetool oil cooling, laboratory constanttemperature control, cooling for small electroplating baths.

3. Retrofitrestricted projects: Projects without equipment rooms, rooftops unsuitable for cooling towers, or sites where property management prohibits coolingwater systems.

4. Phasedinvestment projects: Several units can be installed initially, with extra modular chillers added later as business expands.

VII. Concise Hierarchical Summary of All Previous Models (for Model Selection Reference)

Small Cooling Capacity (≤ 260 kW)

1. Low budget, no cooling tower solution: Air-cooled vortex (modular chiller)

2. Equipment room available, highefficiency priority: Watercooled vortex chiller

Medium to Large Cooling Capacity (260 kW-2000 kW)

1. Cooling tower available for longterm operation: Watercooled screwtype chiller

2. Cooling tower not feasible: Aircooled screwtype chiller

Large scale Non stop Operation with Maximum Energy Saving Requirement

1. Cooling tower available: Watercooled airbearing / magneticlevitation centrifugal chiller

2. No cooling tower available: Aircooled airbearing centrifugal chiller

VII. Maintenance Key Points

1. Clean outdoor unit fins every year. Dust clogging will trigger highpressure shutdown and sharply increase power consumption.

2. Add ethyleneglycol antifreeze to water circuits for longterm winter shutdown.

3. Periodically inspect fanmotor and compressor operating current, and check pipe insulation against condensation.

Model Selection Tip

For smallscale projects with intermittent operation and no coolingtower requirement → select aircooled vortex chiller (aircooled modular chiller).

Precautions for Unit Use

Installation precautions

1. When lifting, positioning, and installing the unit, safety must be taken into account to prevent collisions and ensure the integrity of the equipment.

2. If the unit is installed outdoors, efforts should be made to avoid exposure to wind and rain (except for rainproof types), direct sunlight, or other heat sources that directly radiate; The computer room environment must be kept dry, clean, and ensure good ventilation, leaving space for unit maintenance and upkeep.

3. For air-cooled units, please ensure that there are no obstructions around the unit and reserve 1 meter of space; There is no obstruction within 2 meters of the top of the unit to ensure good ventilation.

4. It is recommended to install the unit on a strong and level ground, and install shock-absorbing rubber pads under the unit chassis to correct the level of the unit. If there are anchor bolts, they must be installed and fixed.

5. The circulating water pump used in conjunction with the unit should be selected and installed according to the data requirements such as water flow rate and water resistance required by the unit.

6. The water pump must be installed in front of the inlet of the unit, and it is recommended to install a filter at the inlet of the water pump to prevent foreign objects from entering the heat exchanger of the unit; If the unit is installed in areas with poor water quality, water treatment must be carried out first to avoid damage to the heat exchanger.  

7. It is recommended to install valves, water pressure gauges, thermometers, water flow switches, and other equipment for the water pipeline system connecting the unit, in order to facilitate the inspection and maintenance of the unit's daily operation.

8. To prevent air from being trapped in the water system, the air must be completely discharged before starting the compressor.

9. The chilled water pipeline must be insulated properly to avoid loss of cooling capacity, condensation, and freezing.

10. The weight of the system connection pipeline shall not be borne by the machine body. Rubber shock-absorbing flexible joints and gate valves shall be installed at the inlet and outlet of the unit to avoid vibration and facilitate maintenance.

11.When configuring wires for the unit, wires with slightly larger cross-sections (with margin) should be selected according to the power consumption, and reliable electronic control components and grounding power sources should be installed to prevent accidents such as overload and leakage.

12. As the unit is equipped with reverse phase and phase loss protection, attention must be paid to whether the line phase is correct during wiring installation. The unit cannot operate normally when the phase is misconnected or missing.    

13. The operator of the unit must observe the operation status of the unit at all times. Once any abnormal situation is found, please promptly troubleshoot. Forced operation will inevitably cause damage to the unit.

Precautions for operation:

1. Before starting up, check whether all water outlets and pipelines of the unit have been correctly installed and connected.

2. Before starting up, check if the power supply of the unit is connected and if the phase sequence is correct.

3. Before starting up, ensure the safety of the power and water sources. Please carefully refer to the equipment operation manual and strictly follow the instructions for use and operation.

Maintenance precautions:

1. Regularly replace the water in the water tank (it is recommended to replace it every 2 months).

2. Regularly clean the radiator of the unit. For air-cooled units, it is recommended to clean the radiator every 3 months; It is recommended to clean the shell and tube condenser and cooling tower of water-cooled units every 6 months (if the usage environment or water quality is poor, it is recommended to shorten the cleaning cycle).

3. If the unit is not used for a long time, please turn off the main power supply; When the ambient temperature is below 0 ℃ and the unit is shut down for more than 6 hours, the unit and pipelines may freeze, and the damage caused by this is not covered by the warranty. 

The best way to avoid pipeline freezing is to completely drain all the water in the unit system!

4. Regularly check the water quality on site to ensure that the water source is qualified (pH ≈ 7). If it contains corrosive substances and causes damage to the unit, it is not covered by the warranty.

5. When the unit encounters unavoidable faults during use, please inform our company of the unit model, component name, and other information so that we can provide you with services more quickly.

6. During the warranty period, our company promises to provide free maintenance services for the unit (excluding human damage, improper use, natural disasters, and uncontrollable factors).

Warning: This unit is a high-voltage, highly specialized mechanical equipment, and should be operated correctly by professional technicians strictly in accordance with the "User and Installation Manual".