ECO2Small - Transcritical CO2 refrigeration booster plant

Marketing Refrigerations Systems 21/08/2013 Page 1

ECO2Small - Transcritical CO2 refrigeration booster plant, for positive and negative temperature

Areas of application

ECO2Small finds its ideal application in areas of small and medium-sale, such as proximity, supermarkets, service stations and discount stores with sales areas until 1000 - 1.500m2.

Range of use

ECO2Small is designed for: • Applications MT (positive temperature) • Applications LV + MT (negative and positive temperature)

Refrigerating power:

MT: Tev=-10°C, Texit gascooler= +35°C, LT: Tev=-35°C, Tcond= -10°C

Utilisateur BT

Utilisateur MT 8 100

3 15

kW 0 10 20 30 40 50 60 70 80 90 100


STANDARD UNIT - TECHNICAL DESCRIPTION

The ECO2Small pack could be provided in different configurations with up to three semi-hermetic compressor for positive temperature and till to 2 compressor semi-hermetic for negative temperature. The positioning of the plant can be for inside or outside installation.

1. structure

The base and the frame are produced on two levels of galvanized sheet metal painted with epoxy-polyester RAL 7035 color. The construction methods of the base is designed to obtain a product of high stability and security.

Technique de jonction avec rivets When it is necessary to connect the profiles in a very stiff way, a special junction with technical riveting is used. Rivets have high strength and establish in a very solid way the different parts that compose the frame. The folded sheet and the use of riveting is designed to minimize vibration of the structure and reduce any potential leaks of refrigerant.


The anti vibration dampers are attached in a suitable position along the longitudinal side of the machine, in order to isolate the pack structure from the support and prevent that vibrations from the machine will propagate creating noise in the building.

They are installed in the factory, so the unit can be placed immediately upon arrival on site.

2. Cover

ECO2Small is equipped with a cover made of galvanized steel sheets painted with epoxy-polyester RAL7035. The panel assembly includes a noise-suppressing coating of 44 mm thickness, composed by:

• polyurethane open cell foam with density of 35 kg/m3 (of self-extinguishing class 2 fire resistance)

• thermoplastic polymer of 5.5 kg/m3 density

•

sound absorbing material

The case is characterized by a simple and fast opening system for an easily accessibility by refrigeration engineer and technical maintenance operations. The panels can be easily removed through the retaining levers of a quarter of a turn and pivot fall protection. In addition, the reduced dimensions of the various panels have been specifically designed for ease of handling.


The casing is completed by an internal system of forced ventilation consisting of:

- Helical coil fan moves the air inside the compartment by pulling it through the chinks - Grid air extraction - Electric thermostat with programmable set point for fan operation (optional)

Extraction grid and air fan

3. Modulation of the cooling capacity MULTISPEED

The refrigeration load required by the appliances undergoes significant daily and seasonal temporal changes. The request for an application can, for example, reduce up to 25% of full charge overnight with display cabinets with manual or automatic curtains (a measure which, in some cases, may also be a saving of 50 %). It is therefore important to have the possibility to modulate the cooling capacity: with ECO2Small this modulation is achieved by using a positive and a negative compressor with separate variable speed inverter regulator. The inverter (variable speed drive), acting on the frequency and voltage of the electric current, varies the number of revolutions of the engine that drives the compressor and, therefore, the cooling capacity. According to refrigeration load, the controller varies the output of the inverter driver in a range of 0-10 Volts. The inverter consequently supply the motor of the compressor with a frequency which varies within a range which changes according to the capacity of the compressor.

Inverter for MT and LT compressors


4. Refrigeration circuit

The refrigeration circuit is composed by:

• Suction line:

- Copper suction collector fully insulated with 19 mm thick Armaflex insulation - Category IV low pressure safety valve - Suction filter with replaceable filter cartridge - To prevent liquid return to the compressors there are two options: a) by liquid-vapor separator (Armaflex insulation thickness of 19 mm) b) or by the injection of hot gas in the suction collector

liquid-vapor separator

Discharge line:

- Discharge line with pipes and manifold in stainless steel - Electronic valve regulation of gas flow in transcritical system (flash gas removal)

Flash Gas Removal electronic valve - Liquid Line:

- Onboard vertical liquid receiver (maximum volume 70 lt) CE approved homologation PS45 bar and 32 mm Armaflex insulation

- Liquid line with bypass filter for easy replacement operations (optional) - Line with Armaflex insulation thickness 19 mm - Double valve supplied in kit - Electronic valve on the receiver for residual gas removing - Indicator and liquid level alarm (optional)


overview of liquid line with insulation liquid line filter detail

5. High and low pressure range and safety valves

Pressures:

Medium temperature: 120 bar on discharge side to the gas cooler and from gas cooler before the high pressure flash gas valve 45 bar for suction line from the appliances to the suction of compressors. Low temperature booster: 45 bar from the discharge line to the suction line of the medium temperature 25 bar for suction line from negative appliances to the suction of the compressor/s. The ECO2Small pack is equipped with: - High pressure safety valve in the discharge collector, ps = 120bar - Low pressure safety valve in the suction line, ps = 45bar (MT) 25bar (LT) - Low pressure safety valve for liquid receiver, ps = 45bar 60 bar operating pressure (instead of 45)on request


6. Pressure switches, control panels and safety control panel:

The power pack is equipped with the following items: HIGH PRESSURE transducer LOW PRESSURE transducer HIGH PRESSURE switch for the compressor with automatic reset, calibrated to 110bar LOW PRESSURE switch for system safety, calibrated to 8 bar (MT + LT) Pressure Compressor LT calibrated to 38bar with automatic reset Gauges HP -ø 63 mm (both MP and LP optional) Connection and service valves

7. Oil system regulation

The oil control system of Eco2Small includes: • Oil separator: in stainless-steel inspectionable and optional bypass for rapid action on

the circuit; mounted on the compressor discharge collector with electronic level indicator.

• Oil reservoir: in stainless-steel, positioned between the separator and the oil distribution manifold for the compressors with two sight glass to check minimum and maximum levels and a safety valve

• Electronic oil level controller (TekLab) for each compressor in order to maintain the optimal lubrication level

By-pass sur séparateur (optional)


Oil level regulator Oil reservoir

8. Electrical board:

The electrical box is wired and tested. It is positioned on the machine in accordance with IEC 60204-1 laws. It allows the control and the setting of compressors and the fans regulation for the optimal management of the refrigeration load


Outside:

• Main switch • Safety switch, lockable in OFF position to allow complete security requirements during

maintenance operations • Warning and alarm lights • external manual switch for each compressor for immediate stop in case of emergency

interventions

In particular, the warning lights are white: presence of voltage on the secondary circuit While the alarm indicators are red if:

• High and low pressure on the general circuit because of the intervention of the relevant safety pressure switches (the plant is shut down)

• Electromechanical backup running (due to an anomaly of the main controller) • Alarm of compressors for: high pressure switch intervention, oil sensor (due to a lack or

insufficiency), thermostat probes (due to overheating of the electric motor), lack of refrigerant in the circuit (optional)

Inside:

• Components are fixed to a bar system that prevent against damage due to vibrations during the transportation and to easily replace of any components.

• The terminals are secured with a spring system against vibrations • The System is provided with high power electrical installation for any kind of work site • The compressor is protected with a magnetic circuit breaker and its related switch • Each compressor is protected against thermal overloads, short-circuits, missing or

unbalanced phase. • The fan on the door is mounted to prevent overheating of the electrical components


The amount of refrigeration power, depending on the real needs by the appliances, is managed by the microprocessor controller located inside the electrical box – Carel or DANFOSS brand. The controller, measuring the value of the suction manifold pressure detected by a dedicated sensor, controls and regulates the switching of the compressors and the inverter. All the display controllers are visible outside of the door for rapid monitoring values.

9. CERTIFICATIONS

The refrigeration plant is built according to the European Directive 97/23/EC on pressurized containers. In addition, the complete certification according to the PED is available for all the models in the range. The whole trial process guarantees the reliability and quality of the product providing that the unit is subjected to rigorous testing at the end of the line. Operations are performed to test the mechanical, electrical and electronics components as codified procedures for each refrigeration unit. A leak test of the refrigerant circuit using a researcher helium leak is carried as well. The refrigerant circuit is successively loaded with dry air. The electrical box according to IEC 60204-1 Legislation is wired and subject to a full internal test.


10. ACCESSORIES

a. Desuperheater

The desuperheater placed between the compressor discharge and the condenser inlet could be used to recover a portion of the heat contained in the gas at the outlet of the compressor heating the sanitary water and saving energy. Desuperheater is a plates heat exchanger made of stainless steel, while the brazing is obtained with copper. The chassis is onboard, on a side of the unit on a dedicated frame of folded sheet metal painted with polyester powder RAL7035 color.

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ECO2Small - Transcritical CO2 refrigeration booster plant