Hybrid Cooling System

Wet/Dry Hybrid Cooling Systems

DVC engineered modular Hybrid  Wet/Dry  closed circuit cooler is designed with purpose of providing maximum water saving, higher dry bulb switch over temperatures, while achieving plume abatement or elimination by utilizing evaporative (latent heat) and dry (sensible heat) modes of cooling, simultaneously.

If air ambient temperature is sufficient to cool down the process water temperature, Hybrid cooler runs in dry mode without spraying water on heat transfer surface and water consumption will be zero.

In higher air ambient temperature water is sprayed on the heat transfer surface and causes inlet ambient air to be cooled. This is called Wet mode or evaporative mode of operation of the Cooler.

• In a sample plant, yearly water consumption for open circuit cooling system vs Hybrid circuit cooling system are compared on the front graph.

• For this sample plant, the  benefit of water saving is showm in the front graph for Hybrid circuit cooling system in comparison to open circuit cooling system.

Performance

Saving water up to 90% comparing to open circuit cooling system
Heavy duty performance

Applications

Metallurgical and manufacturing workshop water cooling
Power plant water cooling
Refinery and petrochemical water cooling

Advantages

High efficiency
Low power consumption
Minimum required footprint
Long life time
Negligible blow-dawn waste
Low maintenance expenses
Clean and free of environmental pollutions
Low noise level

Dry Mode

In the dry mode, the process fluid enters to coil through top coil connections. Fan motor is energized while spray pump is de-energized. The axial fan draws air upward across the coils. As air is passes over the coils, a portion of the heat load is dissipated to the atmosphere through the tube walls and fins using sensible heat transfer. The warm process fluid exist the coils, and then enters the coils through the factory installed piping. The remaining heat load is dissipated through the tube and extended surface fins of coil utilizing sensible heat transfer.The unit will remain in dry mode of operation until temperature set point can no longer be met. In this mode, no water is used and plume is eliminated.

Wet Mode

Once temperature set point can no longer be met, the unit will switch to Wet mode. This mode of operation in the Hybrid cooling utilizes evaporative and dry cooling simultaneously. First, the process      fluid enters the coil through top coil connections. The fan and pump motors are energized. A portion of the heat load is transferred through tube walls and fins to the air passing over the coils. No water is evaporated during this process. The warm process fluid exits the coil, and then enters coils through the factory installed piping. The spray system cascades water over the tubes of the coils while heat is absorbed by the water. Air is drawn upward and over the coils by the axial fan. A small amount of the      re-circulating water is evaporated due to latent heat transfer through the tube and fin walls of the coils. In this mode, water usage is reduced and plume is abated as the saturated discharge air is heated as it passes over the coils