Adiabatic cooler with control system for water and energy use reduction

Abstract

An adiabatic system and method for reducing water and energy use is provided. The system comprises an adiabatic heat rejection system including a temperature sensor configured to measure the ambient wet-bulb temperature of the adiabatic system based on a measured temperature of water exiting a wetted media pad. A method for adjusting the operational parameters of the system to minimize water and energy use is provided. The method comprises the steps of determining an approximate ambient wet-bulb temperature of the adiabatic heat rejection system based on a measured temperature of water leaving the adiabatic pad, determining if a measured temperature of a process fluid stream is above a process fluid temperature setpoint, determining if the adiabatic heat rejection system is in a water conservation mode of operation or an energy savings mode of operation, and adjusting one or more operational parameters based on the mode of operation.

1 . An adiabatic heat transfer system for cooling a process fluid, comprising:
 an adiabatic cooler having:
 at least one media pad; 
 at least one heat exchanger containing the process fluid, wherein the at least one heat exchanger is downstream of the at least one media pad; 
 a fluid distribution system designed to wet the at least one media pad by distributing cooling water over the at least one media pad; 
 a fluid collection system including a basin for the cooling water from the at least one media pad; 
 a recirculation conduit in fluid communication with the basin and the fluid distribution system; and 
 a sensor designed to sense a temperature of the cooling water of the at least one media pad; and 
   a control system designed to adjust one or more operational parameters of the adiabatic heat transfer system based on the sensed temperature of the cooling water.   
     
     
         2 . The adiabatic heat transfer system of  claim 1 , further comprising:
 a cooling water make-up conduit in fluid communication with the basin and a water make-up source.   
     
     
         3 . The adiabatic heat transfer system of  claim 2 , further comprising:
 a first valve designed to control a flow of cooling water make-up through the cooling water make-up conduit;   a second valve designed to control a flow of the cooling water to the fluid distribution system;   a third valve designed to control a flow of the cooling water through a bleed conduit in fluid communication with the basin; and   a fourth valve designed to control a flow of the cooling water through a fluid outlet conduit in fluid communication with the basin.   
     
     
         4 . The adiabatic heat transfer system of  claim 3 ,
 wherein the control system is further designed to determine a mode of operation of the adiabatic heat transfer system when a sensed process fluid temperature is above a first cooling water threshold value,   wherein the mode of operation includes at least one of a water conservation mode and an energy conservation mode, and adjusting the one or more operational parameters of the adiabatic heat transfer system based on the determined mode of operation includes:
 opening at least one of the third valve and the fourth valve to remove the cooling water from the adiabatic heat transfer system; and 
 opening the first valve to add the cooling water make-up to the adiabatic heat transfer system. 
   
     
     
         5 . The adiabatic heat transfer system of  claim 1 , further comprising:
 a second sensor designed to sense at least one environmental condition of ambient air.   
     
     
         6 . The adiabatic heat transfer system of  claim 5 ,
 wherein the control system is designed to determine an evaporation rate of the heat transfer system using the sensed cooling water temperature and the sensed at least one environmental condition of the ambient air.   
     
     
         7 . The adiabatic heat transfer system of  claim 6 , further comprising
 a cooling water make-up conduit in fluid communication with the basin and a freshwater make-up source,   wherein the control system is designed to open or close a make-up valve based on the determined evaporation rate of the heat transfer system.   
     
     
         8 . An adiabatic heat transfer system for cooling a process fluid, comprising:
 an adiabatic cooler comprising:
 at least one media pad; 
 at least one heat exchanger containing the process fluid, wherein the at least one heat exchanger is downstream of the at least one media pad; 
 a fluid distribution system designed to wet the at least one media pad by distributing cooling water over the at least one media pad; 
 a fluid collection system designed to collect the cooling water from the at least one media pad or the fluid distribution system; 
 a fluid outlet conduit in fluid communication with the fluid collection system; 
 a valve designed to control a flow rate of the cooling water through the fluid outlet conduit; and 
 a first sensor designed to sense one or more water quality parameters of the cooling water of the at least one media pad; 
   a second sensor designed to sense at least one environmental condition of ambient air; and   a control system designed to:
 determine an approximate wet-bulb temperature of the adiabatic heat transfer system based on the sensed one or more water quality parameters of the cooling water leaving the at least one media pad; 
 determine an operating cycles of concentration value based on the sensed one or more water quality parameters and the approximate wet-bulb temperature; 
 determine whether the determine operating cycles of concentration is higher than an operating cycles of concentration threshold; and 
 open the valve to drain the cooling water in the fluid collection system in response to determining the operating cycles of concentration value is higher than the determined cycles of concentration threshold value. 
   
     
     
         9 . The adiabatic heat transfer system of  claim 8 , further comprising:
 a cooling water make-up conduit designed to deliver freshwater to the fluid collection system;   a second valve designed to control a flow of the freshwater to the fluid collection system;   a bleed conduit designed to deliver at least a portion of the cooling water to a wastewater system; and   a third valve designed to control a flow of the cooling through the bleed conduit.   
     
     
         10 . The adiabatic heat transfer system of  claim 9 ,
 wherein the bleed conduit is downstream of a recirculation basin of the fluid collection system and upstream of the at least one media pad.   
     
     
         11 . The adiabatic heat transfer system of  claim 9 ,
 wherein the bleed conduit is downstream of the at least one media pad and upstream of a recirculation basin of the fluid collection system.   
     
     
         12 . The adiabatic heat transfer system of  claim 9 ,
 wherein the control system is designed to open at least one of the second valve and the third valve in response to determining that the operating cycles of concentration value is higher than the cycles of concentration threshold value.   
     
     
         13 . An adiabatic heat transfer system for cooling a process fluid, comprising:
 an adiabatic cooler comprising:
 at least one media pad; 
 at least one heat exchanger containing the process fluid, wherein the at least one heat exchanger is downstream of the at least one media pad; 
 a fluid distribution system designed to wet the at least one media pad by distributing cooling water over the at least one media pad; 
 an air movement device designed to induce a flow of ambient air through the at least one media pad and the at least one heat exchanger; and 
 a sensor designed to sense a temperature of the cooling water of the at least one media pad; and 
   a control system designed to:
 determine a mode of operation of the adiabatic heat transfer system when a sensed process fluid temperature is above a first process fluid temperature threshold value, wherein the mode of operation includes at least one of a water conservation mode and an energy conservation mode; and 
 adjust one or more operational parameters of the adiabatic heat transfer system based on the mode of operation. 
   
     
     
         14 . The adiabatic heat transfer system of  claim 13 ,
 wherein in the energy conservation mode, the control system is designed to determine whether the air movement device is operating above a threshold speed setting prior to adjusting the one or operational parameters of the adiabatic heat transfer system.   
     
     
         15 . The adiabatic heat transfer system of  claim 14 , further comprising:
 a fluid collection system designed to collect the cooling water that runs off of the at least one media pad, a fluid outlet conduit in fluid communication with the fluid collection system, and an outlet valve designed to control a flow of the cooling water through the fluid outlet conduit,   wherein adjusting the one or more operational parameters of the adiabatic heat transfer system includes opening the outlet valve to discharge some of the cooling water from the fluid collection system to a wastewater system if the air movement device is operating above the threshold speed setting.   
     
     
         16 . The adiabatic heat transfer system of  claim 14 ,
 wherein the control system is designed to determine whether the sensed process fluid temperature is above a second process fluid temperature threshold value when in response to determining the air movement device is not operating above the threshold speed setting.   
     
     
         17 . The adiabatic heat transfer system of  claim 16 ,
 wherein adjusting the one or more operational parameters of the adiabatic heat transfer system includes:
 increasing a speed of the air movement device in response to determining the sensed process fluid temperature is greater than the second process fluid temperature threshold value; and 
 determining whether the air movement device is operating at a minimum threshold speed setting in response to determining the sensed process fluid is less than the second process fluid temperature threshold value. 
   
     
     
         18 . The adiabatic heat transfer system of  claim 13 ,
 wherein in the water conservation mode, the control system is designed to determine whether the sensed process fluid temperature is above a second process fluid temperature threshold value prior to adjusting the one or more operational parameters of the adiabatic heat transfer system.   
     
     
         19 . The adiabatic heat transfer system of  claim 18 ,
 wherein the control system is designed to:
 determine whether the air movement device is operating above a minimum threshold speed setting in response to determining the sensed process fluid temperature is less than the second process fluid temperature threshold value; and 
 determine whether the air movement device is operating below a maximum threshold speed setting in response to determining the sensed process fluid temperature is greater than the second process fluid temperature threshold value. 
   
     
     
         20 . The adiabatic heat transfer system of  claim 19 ,
 wherein adjusting the one or more operational parameters of the adiabatic heat transfer system includes at least one of adjusting a speed of the air movement device and opening the outlet valve so that at least some of the cooling water in the outlet valve is discharged from the adiabatic heat transfer system.