Process Chilled Water

I am guessing that the extrusion machines will be satisfied with warmer water than 45-50°F. If so, you can use a separate pump loop for the extruders, with a temperature control valve to blend in a relatively small amount of chilled water.

Alternatively, you might be able to use a completely separate cooling tower for the extruders. The initial expense for this extra piece of equipment will be offset over time by not using a compressor for cooling the extruders.

Generally for air conditioning unit, chilled water temp is taken near by 40 degree F, u say for extrusion process, Temp required is more 45 F than that for conditioning unit, means inlet temp for extrusion process shall be neary by 85 degree F, so u can use a heat exchanger along with a variable flow pump ( closed loop) in Extrusion process line to convert the chilled water into cooling water required for extrusion processs. concern heat exchanger party like LHE/GEA-PHE/ALFALAVAL. other option u can go for cooling tower , a seperate cooling water system for extrusion processs. chiller is more costly than cooling tower. u say half capacity is being used for extrusion process. then urr chiller capacity will be reduced half. it may reduce the cost. go for open circuit cooling tower than closed circcuit cooling tower, open circuit cooling tower is less costly. i m not aware about the water quality, RO/Softener may used for make up water, it will add a cost

This amplifies nicely from my very brief description. GA.

While you're here, you might want to take a look at the recent thread on concrete cooling. This sounds like a promising application for your flash-ice system. If you wangle a deal with something like the Three Gorges Dam, maybe you could take me along...

In my opinion you can do it. You have to do careful calculation and add a heat exchanger and a secondary circulation pump in the cooling circuit of machines, so you get return water on the same temperature of AHUs return.

thanks a lot buddies very helpful every comment

The whole system can be done with one pump driving the chilled water in the circuit:

The Chilled water goes first to the AHUs and returns (delta T is not more than 12 deg F usually).

Returning water is still cold enough for the extrusion machines.

If the temp of the water needs to be above a certain value from the temp required for AHUs then a 2nd pump with a 3way valve can be used to mix the incoming water with some of the extrusion process returning water to obtain a more temperate (warmer) cooling water back to the extrusion section. USUALLY, the extrusion process can take a range of temperature and regulate its flow to suit the level of cooling (avoiding condensation of the molds...) at each machine/mold section.

The use of a primary/secondary piping system should be able to satisfy the diverse temperature requirements. That said, you will want to investigate a chiller equipped with a VFD on the compressor depending on the ratio of the process load to the total load. If the location is in a northern climate where the air conditioning load will diminish in the winter or even in summer nights but the process cooling is needed 24/7 you may want to use separate chillers. Long story short an in-depth analysis of your load requirements will drive the design ie, number and size of chillers, pumps and piping design. It's not rocket science but the devil is in the details and those details can't be overlooked in coming up with the final design for trouble free operation and lowest energy consumption at all conditions of service. It's definitely worth the time and work involved. If this is beyond your in-house expertise I would recommend you seek out the services of a competent design/build contractor who is experienced in this discipline. A properly designed, installed and maintained system will pay you a handsome return on investment. Lou Bindner

In his second comment, Tornado mentioned my 'flash-ice" system. This is another option for your customer.

Basically, the system makes sub-cooled water under pressure and flashes it into a slush where the ice float to the top and the 32F/0degC water goes to the bottom for recooling OR to be used as chilled water.

Using the 32F water with a 60F return temp means that you can use pumps and piping that will be about 50% of normal (and use 50% less energy). The thermal storage allows offsetting the HVAC loads to off-peak evening hours, which reduces the overall installed tonnage of the sytem. The system has energy efficiency similar to a standard chiller, no added energy burden from 15F refrigerant. The cold CHW allows the AHUs to make colder (dryer) air, which allows running the spaces at 80F with 35% RH (actually more comfortable than 73F, 50% RH) which lets the AHUs make less air (higher deltaT) so they can also be about 50% smaller and use smaller ducts. The warmer spaces have a lower deltaT with ambient, so cooling load tonnage is lower, adding to the energy savings. Net effect- much lower installed costs and much lower energy usage. Energy savings yields environmental savings with reduced CO2 and NOX from power plants, so this is also a very GREEN installation.

You can run the CHW through a HXU to make whatever temperature secondary CHW is needed by the extruders, so that problem is solved as well. The storage system can operate 24/7 so all loads will be met all the time.