Daikin central chiller systems offer precise environmental control and high COPs
September 1st 2004

Precise environmental control is vital to many commercial and industrial applications. Daikin central systems have proven both flexible and reliable in the provision of chilled or heating water for applications as varied as fish farming, wine and cellar cooling, agricultural, pharmaceuticals, plastics, food production and many other industrial and process requirements Careful development by Daikin of matched compressor and refrigerant combinations has resulted in the evolution of advanced water chillers, fully optimised for use with R-407C and R-134a refrigerants and renowned for their precision, power, low operating noise, easy maintenance and low running costs.

Compressors Daikin was the first company to develop a semi hermetic, single screw compressor for use in refrigeration and the basic structure of the unit has changed remarkably little since its introduction.

Daikin single screw compressors are produced for air and water cooled chillers ranging from 40 to 200hp, operating on R- 407C and R-134a and offering high COPs and 4 to 5 year operating cycles between overhauls. The latest ‘G’ unit in the series incorporates many high tech features such as high efficiency motors, modified screw profiles, new design slide valves and gate rotor shafts.

The company also produces technologically advanced hermetic multiple scroll compressors, optimised for use with its smaller R-407C air cooled chillers and the high motor efficiency levels achieved by these units guarantee high performance and EER ratings.

Daikin chiller scroll compressor R-407C operated Hydrocube units are available in three versions – small air cooled – medium air cooled and small water cooled / condenserless – with capacities of 10 to 55kW, 55 to 250kW and 10 to 55kW. An indoor model for ducted installation with a capacity of 10 to 25kW is also available and can be fully built into cellars, garages and attics and is ideal for refurbishment applications.

Small and medium cooling only and heat pump air cooled Hydrocube models come in 3 basic designs. All models are offered with basic hydronics including flow switch, filter strainer, shut-off valves, air purge, manometer and drain/fill points. Top of the range is an all in version, complete with buffer tank, pump and expansion vessel. A lower specification version incorporates just the pump and expansion tank.

The remarkable range of small water cooled Hydrocube EUW series, offers capacities between 13 and 65kW. The incorporation of water to water technology plus a modularised format, enables these units to be used in cooling applications up to 195kW or heating applications up to 248kW.

Their unique modular concept allows their installation as a stand alone single circuit unit (13kW to 33kW) or as a twin circuit single module (43 to 65kW). With measurements of just 600mm (width) x 600mm (length) x 600mm (height) for the ‘stand alone’ unit, the footprint is some 25% less and volume occupied 50% less, than those of contemporary units.

Daikin has recently introduced a new heat recovery air cooled EUWA series.

Rated at between 199 and 550kW with a single compressor circuit, the units operate on R-407C refrigerant and can be used in either cooling only or heat recovery mode.

Operating range is between –150°C and 430°C ambient. The incorporation of a high efficiency brazed plate heat exchanger on the condenser side enables enough energy to be recovered to produce hot water at between 25 and 55°C.

Optimised balance between cooling capacity and maximum heat recovery capacity is achieved by measuring deviations to the set point of the leaving water and electronically adjusting the target condensing temperature. This enables considerable heat to be recovered across the range.

Larger air cooled EUWA models with capacities between 110 and 540kW are available in R-407C and R-134a variants, suitable for both comfort cooling and industrial/process applications and incorporate the latest Daikin ‘G’ single screw compressor. A complementary range of similar capacity water cooled EUWL units operates on R-134a and is available in ‘with condenser’ and ‘remote condenser’ models.

Control Units up to 65kW are fitted with standard Daikin DDC self diagnostic, electronic control, offering auto restart, LED status display and total integration of all chiller functions within a single controller. Larger units are regulated by a multi purpose, special pCO2 controller, which is able to monitor all operating parameters. A multiplicity of programmable functions can be handled, such as floating set-point, free cooling, double evaporator pump, compressor lead lag, freeze up control and extended alarm history etc

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