Specifications Cooling tower series KAHV - hybrid recooler for closed circuit cooling with axial fans comprising:

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Cecil Lawson
6 years ago
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1 Specifications Cooling tower series KAHV - hybrid recooler for closed circuit cooling with axial fans comprising: Housing The housing consists of a welded, self-supporting, stainless steel framing structure into which the heat exchangers are fitted in a V-type layout. The fan nozzles are drawn from continuous aluminium sheeting (AlMg3) and accommodate the fans. The air outlets above the fans are fitted with plastic-coated protective grilles as per DIN EN 294. The fans are sealed off individually with the help of aluminium sheets (AlMg3) in order to minimise performance losses in the event of a fan failure. Underneath the re-cooling unit, a water collecting tank of stainless steel ensures the collection of surplus spraying water and its drainage via a drain connection. Stainless steel profile rails mounted to the housing frame accommodate the adjustable spray tubing made of stainless steel. Heat exchanger core V-shaped double core with mechanically widened, seamless, copper core tubes arranged in a staggered layout with floating fit. Corrugated fins of high-purity aluminium with hydrophilic coating. Fin spacing: 2.2 mm minimum Flange connections PN 16 at the inlet and outlet side. Low-pressure highperformance spraying system The system comprises horizontally installed stainless steel tubes to which axial hollow-cone nozzles are fitted with the help of mounting clamps. These nozzles provide for fine and uniform humidification of the heat exchangers even with a low inlet pressure between approximately 2 and 5 bars. The nozzle sets are fixed with spigot nuts in the mounting clamps and therefore easy to replace. The of the water volume applied to the fin surface is regulated by motorised fittings that are fitted in the supply tubes and release individual areas of the heat exchanger core for water application depending on the current performance requirements. The entire tube system is slightly sloped to ensure that all water runs off through the drain valve to prevent frost damage in wintertime. The supply line to the re-cooling unit should also be laid with inclination and fitted with a drain facility (not included in the scope of delivery). A pre-filter protects the spraying system against the penetration of dirt. In order to prevent deposits caused by the complete evaporation of the spraying water osmotic water or water of a corresponding quality (conductivity below 100 µscm) should be used for spraying. 1 As of January 2013

2 Fans Axial fans with maintenance-free external rotor motors, made in Germany, protection IP 54, windings with insulators of protection class F, embedded winding thermostats for motor protection. Impeller unit, balance quality grade Q 6.3 as per VDI 2060, with low-noise sickle blades. The fans are suitable for continuous speed (via frequency conversion). Switch cubicle and Switchgear: Switch cubicle design: Type: Rittal Material: stainless steel Dimensions: (H x W x D) 1000 x 1800 x 400 mm Design: single-door cubicle opening to the top. Gas springs keep the door in a horizontal position. It serves as a shelter when open. Protection IP56 Cable entry from below/ cable screw connectors / cable clamping rail Electrical equipment Switching devices Siemens Protective devices Siemens Frequency converter with Profibus ABB / ACS 550 Alternatively: Siemens, Danfoss Sinusoidal filter ABB / NSIN.. Alternatively: Siemens, Danfoss PLC (CPU) Siemens / CPU 313C-2 DP Digital inputs/outputs Siemens Analog inputs/outputs Siemens Operating panel Siemens / OP77A Sensor technology IFM Protection of electrical equipment: All electrical equipment is protected by suitable protective devices. All fuses are fitted with auxiliary contacts, monitored and represented on the display. They are linked to the centralized alarm of the corresponding fan or the general centralized alarm. 2 As of January 2013

3 Communication with the & management system: External release signal Plant-ready-for-operation signal Plant-in-operation signal Plant-failure signal Wet-mode signal Dry-mode signal Bus system: MPI and Profibus are the standard systems used in KTK cooling towers. The bus interface provides for the optional connection to the & management system. All parameters for the and supervision of the cooling tower are included in data block DB100. The & management system can access these data. You can optionally use systems with Modbus, CAN bus, Profinet or any other bus systems. A corresponding gateway should however be available on the market. Programming and documentation software Electrical distribution and installation diagram Eplan 5.7 SC1 PLC programming FBD Simatic Step7 Prof SR4 Operating panel programming Simatic WinCC flexible 2007 Operating panel OP77A: The operating panel offers the following input and output options: You can set all important parameters for the time of need. Information about the status of the device as well as possible failures and alarms are indicated on the panel. In addition, you can manually particular plant components. Options: Control of the spraying water quantity: To keep water consumption as low as possible, a sensor is fitted in the return flow of the spraying system and triggers a speedled pump. The pump adjusts the spraying water quantity. The desired return flow volume can be adjusted via the operating panel. 3 As of January 2013

4 Monitoring of water conductivity: In order to protect the cooling tower against contamination, the water quality is continuously monitored via conductivity measurements. The limiting value is adjustable. If it is exceeded a message requiring the operator to check the water quality is displayed. Password protection of the operating panel: The operating panel provides for multi-user operation. Password protection allows each user to prevent unauthorized manipulation. Night economy: The activation and deactivation of the night economy mode is realised via the operating panel. The switching times for night economy mode and the maximum speed of the fans are adjustable. Functional Description Start-up and shut-down of the system: The system's main switch is fitted to the distribution frame door at the switch cubicle. It is used to switch the power supply of the entire cubicle on and off. A selector switch for manual mode, off and automatic mode is also fitted to this door as well as an emergency off switch. The maintenance switches of the fans are also installed here. Automatic system: Basically, the automatic of the devices ensures the lowest possible water consumption. The start and stop commands for the cooling tower are transmitted via the operating panel OP77A fitted to the switch cubicle door. In addition, the external release signal must be available for operation. If the actual temperature exceeds the set value, the PLC adjusts the speed of the drives according to the outlet temperature. The speed is realized by converters that are connected to the PLC via the profibus interface. If the maximum speed of the fans cannot prevent that the desired temperature is exceeded in dry operation mode, the main valve of the spraying system opens and the spray nozzles are activated as required. The water pressure is monitored during spraying. In the event that the desired temperature cannot be reached, a message indicating that the "limit of performance is attained" is put out after an adjustable interval. 4 As of January 2013

5 If the ambient air temperature drops during spraying or less cooling performance is required for any other reason, an algorithm incorporated in the PLC program switches the spraying system off. This ensures the lowest possible water consumption. If the frost protection system signalises the danger of frost the spraying lines are emptied automatically and the activation of the spraying system is prevented for reasons of safety. Interruption of the operation: If the external release signal is interrupted for any reason, the cooling tower system switches to stand-by mode. Stopping the plant via the operating panel shuts down the system and the external release signal takes no longer effect. 5 As of January 2013

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