PROJECT DESCRIPTION

HOT/COLD REFRIGERATING UNITS – MAXI COLD

 

Two circuits, hermetic compressor.

Suitable for cooling and heating musts and wines, controlling fermentation temperatures, tartaric stabilization and air conditioning rooms with the possibility of managing multiple users at the same time.

Satin 304 stainless steelØ

Structure and paneling in stainless steel, the material of excellence to guarantee durability and aesthetic finish over time.

 

Heat pumpØ

The heat pump cycle inversion system allows heating up to +40°C.

 

TemperaturesØ

Standard programmable temperatures from -10°C to +40°C

 

Hydronic systemØ

Hydronic system installed inside the chiller, with thermally insulated 304 stainless steel open circuit storage tank and water pumping kit managed by one or more multi-impeller 304 stainless steel electric pumps.

 

The MAXI COLD model is a reversible air-cooled chiller, designed for industrial use and outdoor installation (IP65 protection rating). The wide range of available options and accessories allows this machine to meet most needs in the industrial field. The MAXI COLD is therefore the solution for all applications that require high performance, reliability, continuity of operation. All models are equipped with a high-efficiency finned coil, brazed plate evaporator, storage tank. The standard hydraulic storage tank also guarantees excellent precision in temperature control even with highly variable thermal loads to the user and simplifies installation. The units are equipped with a finned pack condenser, axial fans and scroll compressors installed on independent refrigeration circuits. The refrigerant used is R410A.

 

Management is entrusted to a thermoregulator control capable of managing all the main functions, temperature regulation, in complete autonomy, while alarms and blocks are indicated by indicator lights. All units use primary brand components and are designed and produced in compliance with CE regulations. The combination of these solutions allows to improve the energy efficiency values, maximizing the seasonal performance indices ESEER (*) and SCOP (**). The units are available in the standard version with 400V/3/50Hz power supply except for the MINI KRIOS model which is 220V single-phase. Other voltages on request. The liquid chillers, to meet the different system requirements, are available with open tank or closed circuit hydraulic circuitry. The standard product, intended for EEC and EFTA states, is subject to: – Machinery Directive 98/37/EC as amended by 2006/42/EC- Low Voltage Directive 2014/35/EU LV- Electromagnetic Compatibility Directive 2014/30/EU EMC- Pressure Equipment Directive 2014/68/EU PED

 

 

All data reported in this catalogue refer to standard machines and nominal operating conditions (unless otherwise specified).(*) Seasonal energy index ESEER: since specific performance indices are not available for industrial applications in partial load conditions, the seasonal performance indices ESEER are reported for each machine.The seasonal performance index ESEER (European Seasonal Energy Efficiency Ratio) used in the European design context, characterizes the weighted average efficiency of a chiller.This index expresses the ratio between the useful effect (total energy subtracted) and the energy expenditure (electricity consumed) of a refrigeration machine during the entire operating season.In relation to the different operating conditions, and the frequency with which they are reached, these indicators are calculated by assigning a different energy weight to the corresponding performance of the unit. For example ESEER = 4 means that, during an entire operating season, for every 4 thermal kWh subtracted, 1 kWh of electrical energy will be spent on average.

 

(**) Seasonal efficiency coefficient SCOP – EN 14825The Energy-related-Products Directive – Erp (Eco-design) is a framework directive that through specific implementing regulations regulates the eco-sustainable design requirements for all products that use energy, including heat pumps up to 400 kW.The seasonal efficiency index SCOP, defined by the EN14825 regulation, allows the comparison of energy performance between different heat pumps applied to the same building.It is calculated as the ratio between the total energy required by a building during the heating period and the electrical energy consumed during the entire winter period, taking into account that, in addition to the heat pump, the system may include other auxiliary devices such as: – Auxiliary heating systems;- Electrical panel;- Crankcase heaters.

 

Advantages of using the inertial tank In a system dedicated to an industrial process, the thermal load of the user can undergo large and sudden variations, or remain for long periods close to conditions very distant from the nominal ones.Consequently, the Chiller that supplies this system finds itself operating sometimes at maximum capacity and close to the operating limits, sometimes instead with frequent ON and OFF cycles.These cycles are always harmful to the life of the compressors and often insufficient to avoid significant fluctuations in the water temperature, which is also absolutely inconvenient from both an energy and process point of view.The advantages of using the inertial tank installed in all MAXI COLD units as standard can be summarized as follows:- Availability of a reserve of water at a specific temperature for the process that must be controlled: in this way, the “energy stored” in the tank is able to compensate for the imbalances due to variations in the load to the user.- Operation of the compressors in particularly stable conditions: in this way the refrigeration unit can work at a practically constant inlet temperature. Together with the constancy of the water flow, this is one of the essential conditions to guarantee maximum compressor life.- Reduction of the frequency of starts and guarantee of a sufficient duration of each compressor running period and each compressor idle period.

 

Testing All the chillers are tested to assess their correct operation.In particular, the following are verified: – The correct assembly of all the components and the absence of refrigerant leaks;- The electrical safety tests as prescribed by EN60204-1;- The correct operation and control of all the operating parameters;- The temperature probes and pressure transducers; Upon installation, the machines therefore require only electrical and hydraulic connections, ensuring a high level of reliability.

 

Compressor Orbiting spiral scroll compressors with 2-pole electric motor, mounted on rubber anti-vibration mounts and complete with protections against overheating, overcurrent and excessively high exhaust gas temperature values.A crankcase heater powered automatically when the unit stops (provided the chiller is kept powered), prevents the dilution of the oil by the refrigerant when the compressor stops, thus ensuring correct lubrication of the mechanical parts even at low ambient temperatures.Thanks to the limited mass of the rotating components and the absence of suction and delivery valves, scroll compressors have numerous advantages: greater energy efficiency, reduced pressure drops in suction, significant reduction in noise level, reduced vibrations on the delivery, great resistance to liquid shocks.For some models, the compressors are installed inside a compartment separate from the condensing compartment, allowing maintenance activities even with the machine in operation.The models use two compressors connected in parallel or independently for each circuit, which allows to increase the efficiency at partial loads, maximizing the seasonal performance index ESEER (*).This solution, through the “unloading” function, also allows the system to be started and the machine to operate even under conditions that are very different from the nominal ones.

 

Evaporator High efficiency brazed plate exchanger, or 304 stainless steel spiral coil.Installed inside the inertial storage tank, the evaporator with a high exchange surface cools the process fluid that flows in contact with the surface, exchanging heat with the refrigerant fluid that evaporates inside it.This particular technical solution allows it to operate with high flow rates and low operating pressure drops, ensuring a high level of reliability in particularly demanding industrial applications and also with liquids containing impurities.All evaporators used in refrigerators can also handle antifreeze solutions and, in general, other liquids that are compatible with the materials constituting the hydraulic circuit (see materials in contact with the process fluid). Condensing/evaporating coil Finned pack exchanger, made up of copper pipes and collectors, corrugated aluminum fins, and galvanized sheet metal shoulders. They have been designed and engineered to achieve high EER efficiency values ​​both in condenser and evaporator mode.The condensing coils are equipped with a distributor for correct supply of the refrigerant circuits during heat pump operation. The condensation water collection for some models is done by means of a drip tray, which covers the entire base of each coil and is equipped with drain connections.

 

Electric fans Axial suction fans, with die-cast aluminum or die-cast plastic body, sickle-shaped blades inserted in aluminum.Equipped with built-in thermal protection.All fans are statically and dynamically balanced, equipped with an external safety protection grille.The motors used are 4 or 6 poles and of the external rotor type and are protected with a chain of thermistors.The standard regulation is ON/OFF managed by a pressure transducer. High-efficiency inverter fans are available as an option. The electronic inverter switching technology, thanks to continuous and efficient regulation of the fan speed at partial loads, allows for a reduction in consumption together with a decrease in noise levels.

 

Refrigeration circuit The refrigeration circuit includes:- Double mechanical thermostatic expansion valve with external equalization: located at the evaporator inlet (one for cold operation and one for hot operation), they regulate the gas flow according to the thermal load. This valve optimizes the operation of the compressor ensuring a sufficient degree of superheating of the sucked gas in all operating conditions.- 4-way cycle reversal valve: reverses the refrigerant flow when summer/winter operation varies and during defrosting cycles in heat pumps.- Hygroscopic molecular sieve dryer filter: allows impurities and any traces of humidity present in the refrigeration circuit to be retained.- Liquid refrigerant flow and humidity indicator: Located on the liquid line, it allows you to check the correct refrigerant gas charge (presence of bubbles) and the possible presence of humidity in the refrigeration circuit.- High and low refrigerant pressure gauges.- High HP and low LP refrigerant pressure switches.- High pressure transducer: for defrost management and for step or electronic regulation of fans (when present).

 

All brazing for connecting the various components is done with silver alloy and the cold pipes are coated with heat-insulating material to prevent condensation. Structure and paneling Structure and paneling in satin-finish 304 stainless steel, radiator protection nets in flexible plastic or electro-welded stainless steel net. Hydronic group INERTIAL STORAGE TANKAll models are equipped with an open vessel storage tank (containing the evaporator) externally insulated by an insulating and anti-condensation layer. Sized to work in closed hydraulic circuits. The materials used are in 304 stainless steel.HYDRAULIC BY-PASSAll units with plate exchanger are equipped with an internal by-pass between water delivery and return or equipped with a dedicated pump. In the event of an incorrect interception of the inlet and outlet connections, the by-pass allows the integrity of the machine and the pump to be preserved, allowing the passage of a minimum flow rate of fluid necessary both for the intervention of the antifreeze alarm and for the protection of the pump.Warning: the by-pass has the sole purpose of preserving the integrity of the machine in the event of an incorrect closing maneuver of the interception taps. Operation in by-pass with continuous cycles and prolonged periods of time is strongly discouraged.CIRCULATION PUMPS: The pumps are centrifugal type with stainless steel impellers with class IE2/IE3 motors depending on the model (international standard IEC 60034-30) with thermally insulated silicon carbide/silicon carbide/EPDM seals.

 

Electrical panel The electrical panel is made and wired in accordance with the Low Voltage Directive, on electromagnetic compatibility.It consists of an electrical box in polycarbonate or stainless steel, which houses the components fixed on a bottom panel, and a door that opens on hinges and closes on a sealing gasket fixed on the electrical box itself protected by a transparent opening door in polycarbonate and the main switch equipped with a safety door lock (the door cannot be opened without first having removed the power to the electrical panel). The electrical panel made with primary brand components, guarantees the protection against atmospheric agents necessary for installing the chiller outdoors (protection level IP65). The power section includes automatic magnetothermal switches for the protection of power devices such as compressors, fans and centrifugal pumps, a series of contactors and a phase monitor for the protection of the machine from phase failure and incorrect phase sequence. The control section includes the transformer for powering the auxiliaries.

 

Safety and control devices High pressure transducers: Detecting the compressor delivery pressure and are used by the electronic control for the following functions: high pressure measurement and alarm, high pressure unloading, condensation pressure control via electronic or STEP regulation of the fans.Temperature probes: positioned on the hydraulic circuit, they detect: water temperature from the accumulation tank.High and low pressure switches with automatic reset: they are positioned respectively on the high and low pressure side of the refrigeration circuit, they stop the compressor operation in the event of abnormal working pressures. Standard thermoregulator control Control and management are entrusted to a thermoregulator with parameter display on the display.The ease of use of this thermoregulator allows any user to view and modify the main operating parameters of the system. MALFUNCTIONING ALARMS SIGNAL LIGHTS – high condensation pressure alarm;- low evaporation pressure alarm;- antifreeze alarm on the water leaving the evaporator;- thermal protection alarm Also available in the cold-only version.