Wal-mart hydronic system
I've been doing some work at a new Wall-mart super center east of Denver in Aurora and I just think the way they have this system set up is so neet I thought I would sare it with you. I don't know the square footage of the store but it's huge the biggest biggest Wall-mart I've been in.
The hydronic system works on two stages. The first low pressure stage runs at 30 PSI and is the stage the generator exhaust heat exchangers and the low pressure waist oil burners are tied into. Then a second stage pumps bumps the sysem pressure up to 60 PSI on the main loop where the 45 airhandlers and radiant floor heat and snowmelt loopes are tied into.
The store is partially powerd by 6-55 KW natural gas generators, the flue gas off these generators is pumped into a heatexchanger in the boiler room.
The gerator exhaust is then ran through these two heat exchangers. I was geting a 10º rise off these exchangers. The exhaust gas temperature entering these heat exchangers runs around 650º.
Boiler one is a waist oil berner set up to burn the used cooking oil out of the many kitchens in the store.
Boiler two in the system is located a mile away in the car shop where the waist oil is used to bring the return temperature up at the far end of the loop before it makes it's way back to the heat exchangers.
And this bad boy is the guy that gets the work done. This 7 MBTU/HR Rite boiler can take care of the whole facility on the coldest of days. It was around 60º today and the main boiler only fired once the whole day so the smaller boilers and heat exchangers do a good job of keeping up on mild days.
The main heating and cooling loops are circulated with 4-20 HP VFD motors.
Then on top of all that they have a couple arcers of solar pannels on the roof and this.
It's a very impressive setup however due to the fact that they have low and high pressure boilers tied into the same system the TNP on the low pressure waist oil burner blowes when it's circulation pump shut down or there is any kind of pressure spike on the high side of the system. I had to make some adjustmenst on the boiler feed regulatior but I finally got the pressures set to where I got good circulation at the far RTU and the TNP don't blow every day in the car shop, as long as they leave the pump on.
I love overtime I just hate working for it.
Wow, thats a hell of a system for a Wall Mart. I guess in the long run the investment will pay off. Do they run the generators only when they can use the heat from the exhaust?
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Are the using the heat from there refrigeration Units?
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For potable hot water.
Originally Posted by fcs
Due to the higer cost in natural gas and the cost of electricity the generators would be shut down in the summer and they would use the solar pannels and wind generator then rely off commercial power. The gernarators need 60 - 80 PSI of natural gas to run each generator has a copeland gas pressure booser installed.
Originally Posted by Freezeking2000
All the refrigeration is your basic refrgeration equipemnt useing air cooled condensers.
Originally Posted by fcs
Hot water air handlers for heating? What's cooling?
The day I was on the roof it was -5º so I didn't spend a whole lot of time looking things over. The air handlers have hot and chilled water coils. They had one trane chiller on the roof that I saw it looked like it had 6-20 Ton compressors. There is a cooling tower located down by the generators.
Originally Posted by BaldLoonie
I happen to know wally world is on a drum march to be the first store to be ran entirely off the grid, 100%. They are very close to it now in some experimental places. Were talking vegitative roofs, solar, rain collection to propel hydro, the whole array of things.
They have recently begun a research endeavor with Some large fleet manufacturer to get all their delivery semis on non gasoline power also.
I did some training recently down in Bentonville. I gotta tell you. It was a lot of talk and alot of hope and hype and alot of coin I guess being moved torwards this. They as a company are convinced to be off the grid with in 20 years.
As I heard one guy down there who is in the know say to me, "they got the money to figure it out".
If you just think of how massive they are and how much real estate under roof they have and all it takes to run not 1 store but 5000 stores and you use the multiplier of investment based on what they hope to be a return on Investment. It's astounding. They could begin and never end and save money every day, just continuing to push for energy conservancy.
I came away from it a pretty surprised dude.
This is so important to them, that the CEO Lee Scott, has a figure of Data every week of Kilowatt usage per store and overall from around the world.
That is what Walmart is so good at. Harvesting data to perfect the next day what was not done right the previous day.
That really is quite impressive
I'm not tolerating Political Correctness anymore, from now on it's tell it like it is.
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No reclaim on the racks? Hell, even stores around here have full condensing heat reclaim.