Evaporative Cooled Screw Chiller Unit

The Evaporative Cooled Screw Chiller Unit is specifically engineered for industrial process cooling, HVAC chilled-water plants, and cold-chain pre-cooling applications where reliable, energy-efficient chilled water supply is required year-round. All major components are selected from leading global brands and undergo full factory run-testing at rated capacity before shipment.

Key System Characteristics

•Evaporative condensing: Wet-bulb-referenced heat rejection gives 5–8 °C lower condensing temperature vs. air-cooled units at the same dry-bulb ambient, increasing COP by up to 20%.

•Twin-screw compressor: Infinitely variable Vi (built-in volume ratio) and capacity control from 25–100% load with minimal part-load performance penalty.

•Shell-and-tube DX evaporator: ASME-designed, copper-tube carbon-steel-shell construction; optimized for 7/12 °C or 5/10 °C chilled-water temperature difference.

•Factory-packaged: Skid-mounted, factory-run-tested, and shipped in one piece (or two sections for large models) to minimize installation time and field commissioning risk.

•Microprocessor control: Touchscreen HMI with Modbus RTU/TCP interface, auto-start sequencing, compressor load scheduling, and full alarm logging.

Technical Specifications

Performance & System Parameters

Note: Cooling capacity and COP based on: chilled water in/out 12/7 °C, wet-bulb temperature 28 °C, rated refrigerant charge, sea-level altitude.

Standard Model Range

Note: Dimensions are for single-unit configurations. Dual-compressor and tandem-circuit models available for capacities above 1,163 kW. All specifications subject to final engineering review.

Application Scope

The Lynxcool Evaporative Cooled Screw Chiller Unit is well-suited to any facility requiring a self-contained, high-COP chilled-water source with limited footprint requirements. Typical application sectors include:

Industrial Process Cooling

•Pharmaceutical manufacturing: Precise chilled-water supply at 5–10 °C for reactors, fermenters, and clean-room HVAC.

•Chemical and petrochemical plants: Continuous process cooling at stable leaving-water temperature; compatible with glycol solutions for sub-zero secondary loops.

•Plastic injection and extrusion: Mold cooling and hydraulic oil cooling; fast load-following via stepless compressor capacity control.

•Data center cooling: Rear-door heat exchangers or CRAC units fed by chilled water; the low condensing temperature reduces PUE significantly vs. air-cooled chillers.

HVAC and Commercial Building

•Central chilled-water plants: Serves air-handling units (AHUs), fan-coil units (FCUs), and chilled beams in commercial office, hotel, and hospital buildings.

•District cooling: Multiple units in parallel with primary/secondary pumping; suitable for campus or industrial park central cooling loops.

Cold Chain and Food Processing

•Pre-cooling tunnels: Chilled-water supply to plate or spray pre-coolers for fresh produce, seafood, and meat.

•Cold-storage antechambers: Air-handling coil cooling for dock leveller buffer zones where moderate temperatures (2–10 °C) are required.

•Beverage and dairy processing: CIP cooling water, pasteuriser section cooling, and tank jacket cooling.

Core Technical Features

Evaporative Condensing Technology

Unlike conventional air-cooled chillers that reject heat entirely to the ambient dry-bulb air temperature, the Lynxcool Evaporative Cooled Screw Chiller Unit uses an integrated spray-and-coil evaporative condenser. The refrigerant coil is continuously wetted by recirculated water while the fan draws ambient air counter-flow through the coil section. Evaporation of a small fraction of the water absorbs the latent heat of the refrigerant, allowing the condensing temperature to track the ambient wet-bulb temperature rather than the dry-bulb temperature.

In a typical 35 °C dry-bulb, 28 °C wet-bulb ambient condition, an air-cooled chiller may condense at 48–52 °C while the evaporatively condensed unit condenses at 38–42 °C — a difference of 8–12 K that directly reduces compressor pressure ratio, increases volumetric efficiency, and improves COP by 15–25%.

Twin-Screw Compressor with Variable Vi

The compressor incorporates a built-in volume ratio (Vi) slide valve that adjusts the internal compression ratio to match the actual system operating pressure ratio. This prevents over-compression (wasted work) at part-load or low-ambient conditions and under-compression (loss of capacity) at high-ambient or high-load conditions. The result is flat part-load efficiency curves and consistent performance across the full operating envelope.

•Capacity range: 25–100% stepless, via slide valve actuated by the PLC.

•Compressor protection: Oil pressure differential switch, discharge temperature sensor, motor winding thermistors, anti-recycling timer (minimum 10-minute off-cycle).

•Oil management: Thermosyphon oil cooling (preferred) or liquid injection; oil level sight glass; factory-charged with compressor manufacturer-specified oil type and quantity.

Intelligent Microprocessor Control

The Evaporative Cooled Screw Chiller Unit is supplied with a Lynxcool-developed microprocessor controller featuring a 7-inch colour touchscreen HMI. The controller manages all unit functions including:

•Chilled-water leaving-temperature PID control (setpoint adjustable 3–15 °C)

•Compressor loading/unloading with anti-short-cycle protection

•Evaporative condenser fan and pump staging (stepless EC fan option available)

•Water make-up valve and blowdown cycle management

•Full alarm log with time-stamp; remote alarm relay output

•Modbus RTU/TCP communication for BMS / SCADA integration

•Weekly scheduler and demand-limiting input

Compact Factory-Assembled Skid

All components — compressor, evaporative condenser section, evaporator vessel, control panel, refrigerant pipework, and water distribution headers — are factory-mounted on a structural steel baseframe and interconnected before shipment. This factory pre-assembly ensures leak-tested refrigerant circuit integrity, verified electrical continuity, and functional run-testing at full rated capacity before the unit leaves the factory.

•Installation: Unit arrives at site ready for electrical connection, chilled-water piping, and make-up water connection only — no field refrigerant work required.

•Commissioning time: Typically 1 day for electrical/piping connections + ½ day for control parameter setup and first-start verification.

Water Treatment & Drift Eliminator

Evaporative systems require water treatment to prevent scale, corrosion, and biological growth in the spray circuit. Lynxcool units are designed to accept standard side-stream filtration and dosing systems and include:

•Stainless-steel spray nozzles (non-clogging, replaceable)

•PVC drift eliminator blades removing ≥ 99.97% of entrained water droplets (Legionella risk mitigation)

•Bottom sump with sump heater for sub-zero ambient operation

•Automatic blowdown solenoid valve with conductivity-based controller input

•Side-stream 50-micron screen filter

Why Choose Lynxcool

Energy Efficiency Leadership

Lynxcool evaporative cooled screw chillers consistently deliver full-load COP values of 3.8–4.5 and integrated part-load values (IPLV) that exceed ASHRAE 90.1 minimum standards by 15–30%. Over a 10-year service life, the energy saving vs. an equivalent air-cooled chiller typically recovers the unit purchase price difference within 2–3 years in regions with moderate electricity tariffs.

Complete Factory Testing

Every unit undergoes a minimum 4-hour full-load factory run-test on a chilled-water test loop calibrated to AHRI 550/590 conditions. The test report — including compressor suction/discharge pressure, chilled-water in/out temperatures, electrical power draw, and calculated COP — is supplied with every unit as documentary evidence of rated performance.

Broad Refrigerant Compatibility

Standard units are designed for R134a (low GWP, non-flammable, globally available). Legacy R22 and R507 variants are available for markets where R134a supply infrastructure is limited. The unit design uses brazed copper connections throughout the refrigerant circuit and is pressure-tested at 1.5× design pressure before charging.

Application Engineering Support

Lynxcool's engineering team provides free pre-sales support including: wet-bulb temperature analysis for the project site, annual energy simulation (TRNSYS or bin-hour method), piping schematic review, and mechanical room layout drawings. This support reduces design risk and ensures the specified unit is correctly matched to the building load profile.

Competitive Total Cost of Ownership

Manufactured in China to international design standards (ASME, EN 378, GB 150), Lynxcool units offer purchase costs 20–35% below equivalent European or North American branded equipment while delivering comparable performance and build quality. Spare parts are held in stock and available for express shipment worldwide; the unit design uses industry-standard compressor models to ensure long-term parts availability.

Frequently Asked Questions

Q:  How does an evaporative cooled screw chiller differ from a water-cooled centrifugal chiller?

A:  A water-cooled centrifugal chiller requires a separate cooling tower and condenser water pumping system, adding capital cost, pipework, and a separate maintenance burden. The evaporative cooled screw chiller is a self-contained unit — the evaporative condenser is integrated into the chiller skid, eliminating the need for a separate cooling tower, condenser water pumps, and associated basin. Installation is closer to an air-cooled unit in simplicity, while condensing temperatures approach water-cooled levels in efficiency.

Q:  What is the water consumption rate and how does it compare to a cooling tower?

A:  Evaporation in the condenser spray circuit consumes approximately 2.0–2.5 L/h per kW of heat rejection (depending on ambient conditions). This is comparable to an equivalent cooling tower serving a water-cooled chiller. Total system water use — including blowdown and drift — is typically 3–4 L/h per kW of heat rejection. In arid climates where water costs are a concern, dry-cooler pre-coolers can be added to reduce wet operation hours.

Q:  Can the unit operate in cold ambient conditions (winter)?

A:  Yes. Below approximately 12 °C wet-bulb ambient, the spray pump can be switched off and the unit operates as a dry air-cooled chiller using the condenser fans alone. A thermostatically controlled sump heater prevents the spray water basin from freezing at ambient temperatures as low as –15 °C. For sites with prolonged sub-zero operation, an optional glycol-protected dry-cooler pre-condenser can be specified to completely eliminate winter water use.

Q:  What is the minimum order quantity and lead time?

A:  There is no minimum order quantity — single units are accepted. Standard lead time from order confirmation is 8–12 weeks for models up to LynxEC-582; 12–16 weeks for larger models. Express production slots may be available for urgent projects. Full engineering drawings and IOM manuals are provided 2–3 weeks after order placement to support parallel civil and electrical preparation.

Q:  What warranty and after-sales support is provided?

A:  All Lynxcool evaporative cooled screw chiller units carry a 12-month warranty on parts from the date of commissioning (or 18 months from shipment, whichever is earlier). The compressor is covered under the original manufacturer's warranty for the same period. Lynxcool maintains a spare-parts depot with next-day dispatch for standard wear items. Remote diagnostics via the Modbus interface allow Lynxcool engineers to review fault logs and operating data without an on-site visit.