How a Supermarket Refrigeration System Works

most people tripped in supermarkets is just a matter of making the list finding the keys piling all the kids and the dog into the car and making it back home before the ice cream melts the last thing on a shoppers mind however is the painstaking effort that's taken to ensure they take home a quality product oh and it's no small job to make that happen as you can see a mega market such as this it's a far cry from the mom-and-pop stores of days gone by today your grocer must maintain state-of-the-art refrigeration facility not only for comfort cooling but for an assortment of freezers coolers dispensers you name it if it chills cools or freezes it'll be found in today's modern grocery to begin with these produce cases considered to be medium Tim must maintain critical temperatures 35 to 38 degrees to ensure freshness don't want to freeze the leaves off the lettuce 35 to 38 degrees may seem like a lot of room for error however one or two degrees difference can be very critical for example the temperature in this area although in the same case may vary a degree or two from that area depending on the needs of the product these are all medium temp cases but some products got to be cool not cold and for that birthday or special occasion what have you these flowers not only have to be kept in a cool environment but one that's highly humid as well fresh fish has not only kept in refrigerated ambient cases but often on a bed of ice as well all of these exposed or open cases use a curtain of air concept to separate the product from the ambient air some freezer cases such as these actually use three curtains of air to separate the product from the outside ambient air pretty sophisticated huh these cases are considered to be low temp units they're kept at a variety of temperatures depending on their size and whether their horizontal or vertical these closed door cases different from the open ones only in that they run a little warmer about -5 degrees ought to be okay super ice cream ice cream cases need to be kept at about minus 12 degrees for a closed door case or minus 24 for an open case either way they still use the same curtain of air concept dairy like produce is kept it between 36 and 38 degrees there's one product states clearly on the label that that beer has to be served at 37 degrees and there's another line that states specifically in the vendors contract the product needs to be refrigerated from the factory all the way to the consumer that's a mighty tall order I think huh a lot of deli meats and cheeses are smoked and considered ready to use product they're stored at about 32 degrees fresher ready to cook meats are stored at slightly higher temperatures remember spoilage is critical but appearance is important too with poultry even a variance of a couple of degrees can make a product look unfavorable even when it's not how convenient is this this baby not only makes the ice it begs the ice and it stacks the ice ex around here there's a guy that'll even tote the ice out to your truck and load it in your cooler for you this is one of the few machines that operates completely independent for the rest the equipment that we've actually been discussing these blue stacks carry the coolant from the evaporators to the racks of compressors that are located up on the roof up here a refrigerant man or woman is in his very own world look at all of this the compressors that serve all those of apps downstairs are grouped together in racks housed in shacks here on the roof here you can see the line set coming out of the roof and it winds its way towards the rack Shack it's gonna get mighty noisy as we get closer to here Bob makes one oh okay the compressors are grouped together in these rock shacks for convenience safety economy protection from the weather and in general a more technician friendly environment and speaking of friendly these compressors have all been retrofitted to use the more in viral friendly hf CR 507 coolant instead of the ozone depleting CFC our 502 all of these units are for sixty volt 3-phase reciprocating compressors in most cases one compressor will service several vaporators at different temps is that complicated not at all take a look at these evaporator pressure regulators or EP RS back on the outside different temps in the evaporators can be regulated by the EP RS which control the pressure in each individual evaporator resulting in a specific temperature for a specific area refrigerant flow at the evaporator Inlet is still controlled by a TX v as in most default applications and in this case a lot of the factory set valves have been replaced with adjustable units for more precision control and less temperature variation let's go back to the drawing board for a second and get a more visual look at the refrigerant cycle that's represented here as you can see different temps are maintained at each evaporator by different pressures maintained by a separate epr for each area the case severely low temps must include a check valve to ensure that no refrigerant backs up into the lower pressure evap from a higher pressure evap and back at the shack a central processor controls everything okay this CPU doesn't do everything but it does control things such as the defrost cycle and monitors for faults indicated by extreme pressure changes it does afford the technician a quick overview of the status of every operational cooling facility connected to it and that makes life a little easier I'd say for example take a look at how this controller manages the defrost cycle defrost is critical you have to defrost the unit but you want to do it in such a fashion as to not jeopardize the freshness of the product all of these defrost cycles are scheduled by the microprocessor and time for a predetermined length but the sensors will override and terminate the time cycle if the evaporator defrost sooner the schedules and timed links are displayed to avoid unnecessary alarm by an overnight employee who might be looking out for temperature changes in the display case yep this controllers like the nerve center for the whole cooling operation except of course for those ice machines we talked about earlier they're off in their own little world all the other refrigeration condensing units are centralized here in the rack shacks they're not much different from any other condensing call configuration except it's a little more convenient having them all grouped here together for energy-saving purposes the fans only run when necessary ramping up and down as required by the condenser pressures this is controlled by a separate control called the VSD or a variable speed drive the VSD up here may seem high-tech but it's just a sophisticated form of control it's not unlike the controls used very fan speeds for similar or other purposes as needed another energy saving device is the recycling of hot water heated by the condenser coils and stored in these hot water tanks for use elsewhere now that's smart as you can imagine all of these evaporators require a lot of refrigerants this is one of the larger liquid refrigerant receivers used in the commercial refrigeration industry it has to maintain a level of refrigerant sufficient enough to supply all of these evaporators and at the same time have enough room left in it to be able to pump the system down in case of maintenance or repairs and let's not forget Comfort cooling in the middle of all of this refrigeration the comfort cooling here is not much different than it is at your home or office just a little bit bigger and definitely noisier remember indoor ambient temperatures and humidity must be strictly controlled or we'll never get those evaporators down there to cool properly the temperature and humidity sensors are located inside the store near the doors they constantly send the information they pick up back to the main controller [Applause] [Music] you [Music]

Channel: HVACR Career Connect NY

Views: 57,529

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Id: UzmNuOpm93Q

Length: 8min 44sec (524 seconds)

Published: Thu Aug 22 2019