Multi-Mode Adiabatic Cooling System with Deluge Feature

Abstract

An air-cooled adiabatic heat exchanger for cooling fluids having tube bundles for receiving hot process and rendering cooled fluid, operating in three or four modes. In a dry mode, heat is exchanged with dry air drawn through the tube bundles by fans. In an adiabatic mode, air entering the heat exchanger is adiabatically pre-cooled by water-saturated adiabatic pads, while the tube bundles remain dry. In an evaporative mode, the adiabatic pads remain dry, and the tubes are wetted with evaporative cooling water. In an optional fourth mode, both the adiabatic pads and the tubes are wetted.

1 . A fluid cooler, comprising:
 a frame,   one or more pairs of tube bundles arranged in said frame and flanking a plenum,   each of said tube bundles having an inlet header and an outlet header, said inlet header configured and located to receive hot process fluid and to distribute it to a corresponding tube bundle and said outlet header configured and located to receive cooled process fluid from said tube bundle,   each of said tube bundles comprising a plurality of horizontally arranged finned tubes connected to adjacent tubes with tube bends,   one or more fans above said tube bundles configured to draw air through said tube bundles and out through a top of said one or more fans,   one or more adiabatic pads mounted adjacent to air intake sides of said tube bundles,   an adiabatic cooling water distribution system located above said one or more adiabatic pads and configured to selectively deliver adiabatic cooling water to and saturate said one or more adiabatic pads,   an adiabatic cooling water collection tray located below said adiabatic pads and connected to a drain and/or to an adiabatic water recirculation system, including a sump, a pump, and pipes connecting said sump and pump to said adiabatic cooling water distribution system,   an evaporative cooling water distribution system located above said tube bundles and configured to selectively deliver evaporative cooling water to outside surfaces to said tube bundles,   an evaporative cooling water collection tray located below said tube bundles and connected to a drain and/or to an evaporative cooling water recirculation system in turn connected to said evaporative cooling water distribution system,   a plurality of valves located and configured to selectively permit delivery of water only to said adiabatic pads, delivery of water only to said tube bundles, or to prevent delivery of water to said adiabatic pads and to said tube bundles,   a control system connected to said plurality of valves and configured to selectively open and close each of said plurality of valves to selectively operate said fluid cooler in a dry mode, in which no water is delivered to said adiabatic pads or to said tube bundles, in an adiabatic mode in which water is delivered only to said adiabatic pads, or in an evaporative mode, in which water is delivered only to said tube bundles.   
     
     
         2 . The fluid cooler of  claim 1 , wherein said control system is further configured to open and close each of said plurality of valves to selectively operate in a combined adiabatic and evaporative mode in which water is delivered both to said adiabatic pads and to said tube bundles. 
     
     
         3 . The fluid cooler of  claim 1 , wherein said evaporative cooling water recirculation system and said adiabatic cooling water re circulation system are integrated with one-another. 
     
     
         4 . A method for operating a fluid cooler having tube bundles arranged in a frame and flanking a plenum, said tube bundles each having an inlet header and an outlet header, said inlet header configured and located to receive hot process fluid and to distribute it to a corresponding tube bundle and said outlet header configured and located to receive cooled process fluid from said tube bundle, said two tube bundles each comprising a plurality of horizontally arranged finned tubes connected to adjacent tubes with tube bends, one or more fans above said tube bundles configured to draw air through said tube bundles and out through a top of said one or more fans, one or more adiabatic pads mounted adjacent to air intake sides of said tube bundles, a first water distribution system located and configured to selectively deliver adiabatic water to said one or more adiabatic pads, and a second water distribution located and configured to selectively deliver evaporative cooling water to said tube bundles,
 said method comprising selectively operating said fluid cooler in any one of a plurality of modes, depending on environmental conditions, including: in a dry mode, in which no water is delivered to said one or more adiabatic pads or to said tube bundles, in an adiabatic mode in which water is delivered only to said one or more adiabatic pads, or in an evaporative mode, in which water is delivered only to said tube bundles. 
 
     
     
         5 . The method of  claim 4 , further comprising selectively operating said fluid cooler in a combined adiabatic and evaporative mode in which water is delivered both to said one or more adiabatic pads and said tube bundles. 
     
     
         6 . The method of  claim 4 , wherein said evaporative cooling water recirculation system and said adiabatic cooling water re circulation system are integrated with one-another.