The Air cooled Turbocor chiller (TBA) with integrated glycol-loop confines the glycol to the chiller which offers significant energy improvements and reduces the volume and costs of glycol.
Turbocor is known for its highly efficient compressors, that cut emissions, costs and addresses F-Gas, EU and building regulations. The TBA unit is an air-to-water glycol free cooling chiller for outdoor installation.
Units range from 400kW – 1.8MW with the option of more customised solutions depending on the application and specifications and offers a number of unique features; low electrical consumption, using a high efficiency Turbocor compressor and unique evaporator design, combined with high efficiency, low noise EC condenser fans capable of delivering the right amount of air at significantly reduced input power.
The TBA can also be supplied with on-board, inverter driven pumps, giving the installer plug and play capabilities, reducing install time and simplifying site installation. A fast re-start of 180-210 seconds (power maintained to the controller) means that space conditions can be brought back to design within a few minutes.
Using R134a, R1234ze or R513a (XP10) a low GWP refrigerant, which is classified within the A1 safety group (ASHRAE 34-1997 standard). The ground breaking design features of the TBA, ensures refrigerant quantities are kept to a minimum so that it has one of the lowest refrigerant charges on the market.
Free cooling for buildings where elevated water temperatures can be used, opens up the opportunity to turn off compressors and use the integrated dry cooler system, this often means the introduction of glycol. Glycol reduces heat transfer when added to a system, leading to over-sized equipment, reduced efficiency and higher maintenance in addition to the environmental consideration of large amounts of glycol in the building. Limiting the glycol to within the TBA chiller, reduces the impact of glycol, resulting in a more efficient system.
The TBA offers high efficiencies even at partial loads and features all aluminium micro channel condenser coils which offer increased heat exchange and low air pressure drops which minimise fan electrical power.
It also features free cooling water coils manufactured from copper pipes and aluminium fins locked in place by means of mechanical pipe expansion. The water coils are factory tested using pressurised air. New high efficiency generation of flooded evaporator (tube core exchanger) is supplied with either victaulic or flanged connections to suit requirements. The spray technology reduces refrigerant charge by 50%.
ASHRAE’s extended temperature and humidity guidelines in data centres, enables higher temperatures without impacting the internal hall conditions and IT reliability so that the TBA can operate using 22⁰C/28⁰C and maximum operating temperatures of 24⁰C/30⁰C for outlet and inlet water temperatures.
The TBA glycol chiller can operate in three different modes:
- Total free-cooling
- Mixed mode or hybrid free cooling
- Mechanical cooling
Free cooling coils are fitted as standard and activate when the ambient temperature is 2˚C below the temperature of the return water from the system, at ambient temperatures 13 ˚C below the return water temperature, the chiller will deliver 100% free cooling. In free cooling, the system fluid is cooled directly by the glycol circuit and outdoor air, enabling the complete shutdown of compressors. This contributes to maximum energy savings as the outside air temperature can satisfy the entire cooling demand and the compressors are off.
In mixed mode the returning water is higher than the outside air temperature but not cold enough for total free-cooling and the compressors are run to deliver only the additional cooling not achieved by the glycol circuit.
Mechanical cooling is used when the outdoor air temperature is equal or higher than the temperature of the returning water. The compressors then provide the total cooling capacity, just like a conventional chiller.
The environmental benefits include: Low GWP R513a or R1234ze refrigerants, electronic expansion valves with a wider adjustment capacity compared to traditional mechanical valves, therefore there is a much quicker reaction time, using less energy. The two-stage centrifugal compressor with variable speed aluminium impellor is designed to operate without lubricating oil – eliminating oil costs and minimising environmental impact.
The TBA shell and tube heat exchangers are designed with internal baffles to maximise heat transfer along with low pressure drops to minimise pumping power. The spray technology enables 50% less refrigerant to be used.
A number of units have already been sold, including a mission critical data centre in Germany.