Indirect Dry Cooling Systems include a water-cooled condenser, circulating machine groups; circulating water mains and a dry cooling tower accommodating Forgó-type water-to-air heat exchangers. The water-cooled condenser can either be DC Jet or Surface Condenser type.
HELLER INDIRECT DRY COOLING SYSTEMS®
Optimized life cycle costs in focus
Invented by ENEXIO in Hungary in the early 1950s, Heller System® has gained worldwide recognition as the ultimate dry cooling choice where minimum life cycle costs are in focus.
THE MAIN BENEFITS ARE:
- Low operational cost and highest operational availability
- Noiseless and can dminish ground level pollution
- Lowest vacuum space among dry power cooling systems
- Provides ultimate resistance to freezing even in partial load winter operation
Natural Draft Dry Cooling Towers are one of the key components of our System contributing to its low auxiliary power consumption. Natural draft dry cooling towers can either be of hyperbolic reinforced concrete structure or aluminum-clad steel structure. Owing to its inherent features, the natural draft tower equipped Heller System® is practically noiseless.
The huge thermal of the natural draft cooling tower lends itself to exhausting the clean flue gas via the concrete structure Heller dry cooling tower, thus saving investment and O&M costs and resulting in lower ground level concentration of remaining airborne pollutants. The tower either accommodates short metal stacks (stack-in-tower) for CFB boilers, or the wet scrubber of wet flue gas cleaning (FGD-in-tower).
Mechanical draft Heller dry cooling towers are either cell-in-line or circular. The low visual profile, low noise, induced draft design enables siting of power plants in densely populated urban areas. Constrained plot areas do not restrict application of dry cooling, designs of different tower height, width and length are available. Winter-proof design makes the system applicable in harsh winter climate (even beyond the Polar Circle) and solutions are also available for extreme hot environment.
The Direct Contact Jet Condenser is key to our competitiveness. Lack of finite surface and lack of physical barrier of tubes of a surface condenser ensure better vacuum achieved by the same size cooling tower, or requires smaller cooling tower to achieve the same vacuum. Space under vacuum is the same as with Surface Condensers, which makes hogging of vacuum quick and holding simple. Excess pressure of the cooling water returning from the cooling tower is utilized in recovery hydro-turbines on common shaft with the circulating water pump and the driving motor, thus saving 30-35% of pumping power. Compared to Surface Condensers the DC Jet Condenser is inexpensive, and is practically maintenance free. DC Jet Condenser design is modular; solutions are available for every turbine output and exhaust direction.
Surface Condenser equipped systems are applied when physical separation of the power and cooling water circuits are necessary. Nuclear power plants and town heating combined heat and power plants are examples for such application. Pump and driving motor comprise a circulating machine group in these cases. Solutions are available for every turbine output and exhaust direction.
We offer a wide variety of seasonal and auxiliary air coolers utilizing the features of the integrated plate fin Forgó-type heat exchanger. Tube and header materials vary according to the duty and the customer’s specification. The medium to be cooled can either be the circulating water of extended heating systems (seasonal coolers), or any kind of closed cooling medium (water, antifreeze or oil).
Delugeable coolers (air-cooled heat exchangers) are offered where it is impossible or economically not viable to fulfill the cooling task with all-dry cooling, and water is available in limited amount for deluging. Delugeable coolers are cost effective compared to an all-dry design and offer flexible operation due to high all-dry operation ambient air temperature limit.
Oil and gas coolers for the oil and gas industry are offered based on Forgó-type heat exchangers.