A heat exchanger is primarily used for cooling the hydraulic fluid of the intensifier pump. Typically the hydraulic oil temperature must be kept below 120° F (49° C). The heat exchanger will require a consistent water flow of 0 to 8 gpm (0 to 30 liters per minute) at an inlet temperature not exceeding 70° F in order to keep the hydraulic fluid at the proper temperature. Actual volume of water will depend on the pump selected. As many pumps are thermostatically controlled, when the pump is cool, it may be that no water is required.
This cooling water must go to drain. The cost of this water must be balanced against the costs of the other two cooling options (air-over-oil and chiller), which would not have any water going down the drain.
Public utility water is usually acceptable for cooling purposes. In situations where the water contains heavy mineral deposits, the exchanger tubes may eventually become restricted by particle buildup. If this is a chronic problem, pre-filtration and/or water softening may be necessary.
Depending upon plant setup, ambient temperature can also be a factor in cooling the hydraulic fluid. Additional cooling may be required if the intensifier and/or heat exchanger is confined to a small, high-temperature space.
2. Air-Over-Oil Cooler
Some pumps will use an oil-air cooler to remove heat from the hydraulic oil, so no heat exchanger is required. In the summer, the unit can be vented outside the building to remove the heat from the building. In the winter it can be vented inside the building to help out with heating the building.
A chiller can be used to re-circulate the cooling water that is used by the intensifier's heat exchanger. It cools the water and then sends it through the heat exchanger again, creating a closed loop. A chiller is most effective in worth considering in a few situations in particular:
Warmer climates where the efficiency of the heat exchanger may be reduce
Facilities that cannot send any water to a drain,
Parts of the country where there is a water shortage, or if the cost of water is high, because a 50 HP pump can use up to 5 gpm for cooling the hydraulics.
The chiller will only reuse the cooling water; you will still be putting approximately 1 gpm with a 50 hp pump of fresh water through the cutting head, which will not be reused with the chiller.
Incoming water for the intensifier should also be maintained at 70° F (21° C) or cooler for best high pressure seal life. If this temperature cannot be maintained, then the chiller can also be used for this water.