Refrigerator Training System

The Atto Labware India Refrigerator training system is a premium, DAQ – type educational unit explicitly engineered for the laboratory study of refrigeration thermodynamics and advanced system performance analysis. Operating on a single-stage vapor compression cycle utilizing environmentally friendly R134a refrigerant, the trainer enables engineering students to comprehensively map refrigeration cycles, plot real-time pressure–enthalpy ($P\text{–}h$) diagrams, determine superheating/subcooling, and analyze varying thermodynamic efficiencies under controlled heat source/sink conditions.

Technical Specifications

1. Mechanical Construction & Bench

• Structure: Heavy-duty, movable industrial aluminum profile framework providing high durability and modular flexibility.

• Dimensions (Minimum): $1300\text{ (L)}\times 700\text{ (W)}\times 1700\text{ (H) mm}$.

• Mobility: Mounted on four (4) robust castors for easy laboratory layout reconfiguration:

  • Two (2) castors equipped with integrated locking brakes.

  • Two (2) castors without brakes.

• Front Demonstration Board:

  • High-contrast, industrial silkscreened refrigeration circuit diagram.

  • Clear, standardized labeling of all mechanical and electrical control components.

  • Color-coded refrigerant piping pathing (Red for High-Pressure/Vapor lines, Blue for Low-Pressure/Liquid lines) to enhance step-by-step cycle tracking.

2. Core Refrigeration Circuit Components

• Hermetic Compressor: Heavy-duty educational grade with a minimum capacity of 1/8 HP, a displacement of approximately 4 {cm}^3, and a cooling capacity of approximately 329W (compliant with the EN 12900 standard).
• Water-Cooled Condenser System: High-efficiency spiral copper coil (12 {to }14 turns) constructed from minimum 1/4-inch outer diameter tubing, fully submerged in a dedicated condenser water tank. Total heat transfer area is approximately 0.082 {m}^2.
• Water-Cooled Evaporator System: High-efficiency spiral copper coil (7 { to }9 turns) constructed from minimum 1/4-inch outer diameter tubing, fully submerged in a dedicated evaporator water tank. Total heat transfer area is approximately 0.049 {m}^2.
• Water Circulating Pumps (Quantity: 2 pcs): Dual-circulating system designed to allow water circulation between the tanks during steady-state heat pump and cooling cycle experiments.
• Operating Voltage: 220 {V} pm 10
• Power: Approx 165W
• Control: Adjustable manual controller featuring three (3) distinct power/speed settings.
• Flow Rate: Approximately 40 {L/min} throughput capacity.

• Expansion Device: Premium internal balance Thermostatic Expansion Valve (TEV) for precise refrigerant flow regulation.

• Filter-Dryer: Heavy-duty inline filter-dryer with standard minimum 1/4-inch service flare connections.

• Service & Isolation Valves: Flared thread connections utilizing minimum 1/4-inch pipe diameters for safe system maintenance and isolation testing.

• Sight Glasses (Quantity: 3 pcs): Structurally installed at critical fluid-state transitions to visually monitor refrigerant phase changes:

• One (1) on the liquid line.

• One (1) on the suction line.

• One (1) directly at the evaporator inlet.

3. Electrical & Safety Control Parameters

• • Main Power Input: Single Phase, $220\text{V}\pm 10\%$, $50\text{Hz}$ AC line input.

  • Rated Current System Capacity: Minimum 10A.

  • Residual Current Circuit Breaker (RCCB): Integrated leakage protection rated at a minimum of 16A.

  • System Overload Protector: Dedicated safety breaker rated at a minimum of 5A.

  • Primary System Switches:

    • Self-locking industrial Key Switch for instructor power authorization control.

    • Self-locking, high-visibility red Emergency Stop Button.

  • Status Indicators: 3  Industrial panel-mounted LED status indicator lights signaling real-time system operational phases (Power, Compressor, Pumps, RV/Cycle status).

Instrumentation, Sensors & Data Acquisition

1. Panel Meters & Gauges

• • Low-Pressure Gauge: Dial manifold type, scaling from -30 to 260 psi.

  • High-Pressure Gauge: Dial manifold type, scaling from -30 to 550 psi.

  • Pointer Voltmeter: Analog panel meter monitoring line voltage from 0 to 250V.

  • Pointer Ammeter: Analog panel meter monitoring total current consumption from 0 to 5A.

  • Integrated LCD Module: Central digital display panel for crisp, real-time tracking of multi-point sensory measurements simultaneously.

2. Electronic Sensors & Transmitters

• • Pressure Transmitters : Dual 4–20 mA current loop transmitters measuring across a 0–2 MPa range for immediate, high-accuracy cycle tracking on the high/low pressure lines.

  • Temperature Transmitters  : Precision PT100 platinum resistance temperature detectors installed at strategic cycle state points.

  • Digital Thermometers : Standalone local digital indicator modules processing localized thermodynamic readings ranging from -40°C to +90°C.

  • Tank Temperature Monitoring: Independent dedicated water tank temperature sensors for tracking fluid thermal storage behavior over time.

3. Integrated Data Acquisition System (DAQ)

• • Hardware: Built-in multi-functional industrial DAQ module featuring an analog input module and an advanced electrical power monitoring module. Connects seamlessly to a computer via an included high-shielding USB interface cable.

  • Capabilities: Features real-time high-precision data acquisition, supporting both manual snapshot logging and customizable automated recording intervals.

  • Software Interface: Includes user-friendly, licensed graphical software providing customizable layout displays, digital instruments, and real-time interactive plotting charts.

Mandatory RFID Power Management System

To support laboratory resource tracking and secure student authentication, the trainer features a fully integrated 13.56 MHz High-Frequency RFID control panel:

• Communication Interface: Standardized RS485 physical layer bus topology.

• Protocol Support: Full compliance with ISO-15693 card structures; supports ModBus_RTU and ModBus_TCP automation commands.

• User Interface: Crisp, panel-mounted OLED display showing authorized card details and runtime, complemented by dual LED indicators and audible status prompts.

• System Functionality: Hardware-locked power contactor activation; power to the refrigeration circuit is only energized upon valid data verification through the central administration software parameters.

Scope of Supply (Turnkey Deliverables)

When you supply this system, the customer receives a fully operational, integrated learning workstation package containing:

1. The Refrigeration training system Bench: Main profile structure containing the complete operational R134a water-submerged circuit, control fascia, and DAQ electronics.

2. Data Acquisition Software: Proprietary educational package for data export, chart compilation, and $P\text{–}h$ mapping.

3. Branded Desktop Computer (HP, Dell, or equivalent approved):

   • Processor: Intel Core i5 (10th Gen or higher, minimum 12MB cache, 2.5 GHz base frequency).

   • Memory & Storage: 8GB DDR4 RAM paired with a 1TB SATA HDD (or better).

   • Display: Minimum 21.5-inch monitor (minimum $1366\times 768$ resolution) with VGA/HDMI interfaces.

   • Peripherals: Matching brand USB keyboard and optical mouse.

4. Uninterruptible Power Supply (UPS): Premium Offline UPS with a minimum capacity of 650VA, providing a minimum of 10 minutes of full-load backup protection for the supplied PC and monitor assembly.

5. Complete Documentation Suite: Technical manuals, step-by-step student experiment guides, teacher answer sheets, instrumentation calibration certificates, and electrical schematics.

Target Laboratory Learning Capabilities

• Practical training in reading and executing industrial refrigeration schematics.

• Plotting and analyzing real-time Pressure–Enthalpy (P – h) charts.

• Calculating the Coefficient of Performance (COP) for both cooling and heat pump configurations.

• Determining refrigerant superheat at the compressor suction and subcooling at the condenser outlet.

• Formulating strict refrigeration energy balances across water-submerged heat exchangers.

• Evaluating compressor volumetric and isentropic efficiencies.

• Directly comparing actual vapor compression cycle data with the ideal Inverse Carnot Cycle.

• Analyzing the direct mathematical influence of shifting heat source and sink temperatures on overall system efficiency.