Aquatech, one of the recently established companies of the Piovan Group, with core competences in industrial cooling systems, makes its debut on the market with an engineering solution that supersedes the principles of centralized systems, to ensure greater energy efficiency and savings of between 35 and 50%. The Flexcool solution, in fact, can use ambient temperature to cool the processing equipment. Such a peculiar strategic feature makes Flexcool ideally suitable to serve sets of injection moulding machines having diverse characteristic, that is, in work situations where different users are present and operating at varying processing conditions (temperature, flow, pressure). Flexcool ensures the highest level of control, flexibility and energy efficiency.
The conventional design of a centralized cooling system suffers of substantial thermal energy losses. The chiller, for example, produces cooling water at one temperature, the lowest necessary, for all equipment, moulds, and hydraulic circuit of the machinery. No matter whether some of the inj.m.machines are of the latest generation or the moulds that equip those require a higher temperature or a lower flow, the cooling system will operate in the worst condition possible forever. Flexcool instead consists of a central dry cooler of the Aryacool line coupled to a series of thermochillers of the DigitempEvo line. One DigitempEvo each inj.m.machine. In this way, it is possible to achieve the optimum operating cooling temperature, water flow and pressure for each machine, depending now on production specifications and not anymore on equipment limitations. The first improvement, immediately appreciable, is the obtainment of an average electricity savings of 35%. Each DigitempEvo is equipped with a digital scroll compressor and an electronic expansion valve: these two components allow optimization and stabilization of the water temperature control and reduction of the energy required to cool it, without fluctuations or losses. The Flexcool solution can produce savings in excess of 50%, as under normal operating conditions most of the heat load is handled by the Aryacool drycooler, while the DigitempEvo refrigerant circuit is only activated for those moulds requiring a cooling temperature lower than that produced by the Aryacool unit.
The heat load issue is crucial to understanding the technical reasons behind Flexcool.
At a manufacturing site, the cooling system must be sized for the maximum heat load, which can only be achieved if all the machinery is in operation at the highest throughput, while the ambient temperature is the highest along the course of the entire year. This condition reflects a purely theoretical operating model. In reality, a cooling system will always work at partial loads, which is a critical condition by nature, as it imposes alternate cycles of start-up and shut-down, that make the system highly inefficient.This problem is completely eliminated by Flexcool, which optimizes cooling capacity distribution as a function of the individual mould characteristics. The digital compressor with which each DigitempEvo is equipped, modulates its capacity between 20 and 100%, depending on the thermal load. The flexibility of Flexcool is therefore particularly appreciated in the presence of partial and variable loads: a condition that systematically occurs.
Flexcool system by Aquatech
The main components of a Flexcool solutions are two, the Aryacool drycooler and the DigitempEvo thermochiller.
The Aryacool drycooler performs at the highest level of efficiency for a temperature differential between the environment and the cooling water of up to 5 degrees. The temperature of the water cooled by Aryacool can be, in some circumstances, higher than 5 degrees above the ambient temperature, but this condition is sporadic and occurs when extraordinary ambient temperatures are reached. On the other hand, a traditional dry cooler is sized for a temperature differential of 10 degrees, not 5, cutting in half the efficiency of operation. Aryacool in short guarantees much greater energy efficiency, which allows for a rapid return on the investment.
The DigitempEvo thermochiller controls flow and pressure of the cooling water, with additional capability of simultaneously control two different temperatures, for two separate circuits, that can be adjusted between 5 and 90° C. Normally, a mould is composed of a fixed part and a moving one, which require two different temperatures. DigitempEvo manages these temperatures using a single device, as any unit of the DigitempEvo line is equipped two circuits, two pumps and two temperature controllers.
Unlike centralized systems that typically require two separate water distribution lines, one for the cooling water from the dry cooler or the cooling tower and the other one for the chilled water from the central chiller, in a Flexcool system the water is distributed through a single circuit at ambient temperature, which does not require insulation: this is low pressure, service water. This very simple configuration represents considerable savings on the cost for the piping, the insulation and the labour to install it. In rough numbers, the piping set up for a Flexcool solution costs 25% of that for a conventional centralized chilled water system. Flexcool is a flexible and most of all an expandable solution, that grows with the expansion of the production capacity of the plant. A conventional centralized chilled water system must be size for the possible maximum capacity of the plant from day one. Flexcool can grow with the increase of the number of inj.m.machines, as with each new machine a DigitempEvo will be required. The investment will be much lower and gradual
Aryacool comes in two versions: adiabatic and self-draining.
In the first, a series of sprayers nebulize water on evaporative panels, so to work at ambient temperatures that exceed 35 degrees; this solution uses the wet bulb temperature of the air and allows cooling water to be produced at a temperature below the ambient temperature (dry bulb).
It is an effective and efficient system: the evaporative panels have a honeycomb structure. The water that is spayed of the panels cools, by evaporation, the water that circulates in the cooling coils. The draining solution is indicated for cold climates, because, when not in operation, the system will drain automatically without the use of antifreeze and without water leakage, with the water being transferred to indoor storage tanks, maintaining the integrity of the components. Antifreeze would reduce the ability to exchange temperature and would require control procedures for its disposal.
