I am upgrading some cooling tower controls and would like to monitor sump temperature as compared to ambient wet-bulb temperature. My weather station reads dry-bulb and relative humidity.
I'm willing to assume constant barometric pressure. Does anyone have a nice set of expressions I can use...
We are replacing chilled water and steam valves that have pneumatic actuators. The steam valve operates between 4 and 8 psi. The chilled water valve operates between 9 and 13 psi. We still want to use pneumatic actuators, but we have an electronic control system that can drive both valves...
I just joined a food manufacturing company that has four(4) 200-hp boilers. The operator runs all four units at about 20 - 30% rated load. He says that we want to minimize flue gas temperature in order to maximize efficiency. Running at 25% keeps the flue gas temperature down.
Is this the...
We have 29 air handling units on the roof of a machine shop that covers about 25 acres. Chilled water and steam are used to maintain space conditions, although we cool for most of the year because of internally-generated heat.
We modulate air dampers to control return, relief and make-up air...
We have four (4) large centrifugal air compressors (900 - 1500 hp) that run at constant speed to supply a general 100-psig header in our factory. The air demand is somewhat variable and it takes the capacity of 2 or 3 compressors to meet the plant requirement. On occasion, we vent air to the...
We have some 20 year old AHUnits, each rated about 60,000 cfm. They have chilled water and steam coils. They also have twin supply fans (vane-axial with pitch control). The pitch controls are frozen in random positions, resulting in actual air flow of 60 to 80% of rating. I vote to toss the...
Would someone please suggest a web site / source for historical weather data? I need heating and cooling degree days by month for 2001 - 3 in southern North Carolina, US.
Thanks.
I have two(2) 1000-ton centrifugal chillers and four(4)variable-speed pumps sending 39 deg F chilled water to the primary side of eight(8) plate and frame heat exchangers. My customer circulates water on the other (secondary) side of the heat exchangers. My obligation is to hold 42 degress F...
I have an engine room with ten (10)ammonia screw-type compressors (400 - 1250 hp) pulling suction (5# and 25#) on an ammonia system in a large manufacturing facility.
I want to measure the cooling load. I can get compressor motor currents, ammonia temperatures and pressures. But don't I need...
Any words of wisdom on the practical limits of HART protocol in terms of loop length, etc. for digital communication of instrument transmitter data in a factory?
Wire type/size, maximum number of transmitters, noise problems, etc.
Is this the right forum?
Thanks.
We are rebuilding some large (20,000 cfm)industrial air handing units that use chilled water for cooling. We have control of individual dampers and can also modulate the chilled water valve and fan speeds. We plan to optimize the AHU controls for minimum energy.
We also plan to modify the...
I need to install flow meters in our plant air system (90 psig). Total capacity of all compressors is about 7500 cfm. The only other information I have is pipe sizes (4, 6 and 8 inch steel, and 2-inch copper)
Please suggest a typical design velocity or other method to estimate flow meter...
