Evaporative cycles of concentration control
A cycles of concentration (COC) control process and system for an evaporative media cooling system having a water storage tank in fluid communication with a drain valve and a refill valve is disclosed. In one step, the COC control process includes the step of executing a plurality of discrete refill events to maintain a level or volume of water within the storage tank. In another step, the COC control process includes the step of executing a discrete drain event, equaling the volume of a refill event, after a discrete refill event has been executed when necessary to maintain a target cycles of concentration value of the water within the storage tank. In one embodiment, a discrete drain event is executed when the number of refill events is greater than or equals a target cycles of concentration of the water in the storage tank.
1. A cycles of concentration (COC) control process for an evaporative media cooling system having a storage tank in fluid communication with a drain valve and a refill valve, the COC control process including the steps of:
a) initially filling the storage tank with water to a first level, the water containing non-evaporative solids at a first concentration;
b) setting a target cycles of concentration setpoint;
c) setting a refill valve counter value to a zero value;
d) detecting that some of the water has evaporated from the storage tank down to a second level below the first level, wherein the water has an increased non-evaporative solids concentration as compared to the concentration at initial filling of the storage tank;
e) refilling the storage tank back to the first level by executing a discrete refill event thereby reducing the non-evaporative solids concentration of the water in the storage tank, the discrete refill event including opening and closing the refill valve to add make-up water to the storage tank;
f) incrementing upwardly the refill valve counter value by a value of one;
g) repeating steps d) to f) until the refill valve counter value equals or exceeds the target cycles of concentration setpoint;
h) executing a discrete drain event in response to determining that the refill valve counter value is greater than or equal to the target cycles of concentration setpoint, the discrete drain event including opening and closing the drain valve to drain water from the storage tank; and
i) subtracting the target cycles of concentration setpoint from the refill valve counter value upon the occurrence of the drain event and returning to step e).
2. The cycles of concentration (COC) control process of claim 1 , wherein:
a. the step of executing a plurality of discrete refill events to maintain a level or volume of water within the storage tank includes sensing a level of water within the storage tank.
3. The cycles of concentration (COC) control process of claim 2 , wherein:
a. the step sensing a level of water within the storage tank includes utilizing an array more conductivity sensors.
4. The cycles of concentration (COC) control process of claim 1 , wherein:
a. the step of executing a refill event includes opening and closing the refill valve for a predetermined amount of time.
5. The cycles of concentration (COC) control process of claim 4 , wherein:
a. the step of executing a discrete drain event includes opening and closing the drain valve for a predetermined amount of time.
6. The cycles of concentration (COC) control process of claim 1 , wherein:
a. the step of executing a discrete refill event includes opening and closing the refill valve until the water in the storage tank has reached a predefined level.
7. The cycles of concentration (COC) control process of claim 6 , wherein:
a. the step of executing a discrete drain event includes opening and closing the drain valve until the water in the storage tank has reached a predefined level.