Refrigeration

Thermotronics » Refrigeration

Refrigeration or cooling process is the removal of unwanted heat from a selected object, substance or space and its transfer to another object, substance or space. Removal of heat lowers the temperature and may be accomplished by use of ice, snow, chilled water or mechanical refrigeration that uses mechanical components arranged in a “refrigeration system” for the purpose of transferring heat. Both refrigeration and air-conditioning are based on the same mechanism: a fluid, generally water or air, is cooled by evaporation of another fluid, called the refrigerant. The refrigerant circuit, comprising the compressor, evaporator, condenser and expansion device, is an integral part of both systems. Nonetheless, there are substantial differences between refrigeration and air-conditioning systems, for example as regards the components, the design methods, the commercial or industrial structures where they are installed and their operation, such as to justify the existence of two distinct market sectors. Refrigeration is one of the most important applications in the food industry, as it slows down the growth of bacteria in food, preserves organoleptic properties and extends shelf life. The mechanical refrigeration system is essentially the same whether it is a domestic refrigerator, a low-temperature freezer, a comfort air-conditioning system, an industrial chiller or a commercial cooling equipment. The refrigerants will be different and the size of the equipment will vary greatly but the principle of operation and the refrigeration cycle remains the same. For this field, De Lorenzo has designed both simulators and demonstrators. The simulators, with the help of a CAI software, are developed to simulate the refrigerating cycles and the behavior of the refrigeration system in many different environments such as refrigerating cycles with liquefied gas evaporation/compression and absorption/diffusion, domestic refrigerating system with single or two temperatures and domestic freezer, refrigerating unit for food distribution (natural or forced circulation, island for frozen food and mixed cold cabinet) and industrial store with positive temperature store for food refrigeration and preservation and cold temperature store for the preservation of frozen food. Two of the latter four simulators are also available all-in-one two-side simulator. A fault simulator, for troubleshooting, is provided in all of them. There are available other trainers with real components such as a refrigeration unit consisting of an air-conditioning and refrigeration systems with control panel and detection of the pressures, a bench consisting of a refrigeration chamber with a forced flow evaporator fed by thermostatic expansion valve and 250W condenser unit with a transparent heated access panel and control system via PLC, a heat pump module (which comprises compressor, circulation pump, accumulator tank, water flow meters, temperature and pressure sensors, etc.) and a refrigeration system consisting of a refrigeration and freezing units mounted on a metal structure integrated with a didactic panel, complete with a fault simulator for troubleshooting. They are recommended for professional institutes, vocational schools and technical colleges.

Products Details

REFRIGERATING CYCLES

The simulator allows the study, the performing of experiments and the troubleshooting for the following systems:
• Refrigerating cycle with liquefactible gas evaporation/ compression;
• Refrigerating cycle with absorption/ diffusion.
These systems are reproduced on the panel, through a colour representation which allows a complete analysis of the fluid circuit, of its components and of the electrical/electronic circuit for control and regulation.
TRAINING OBJECTIVES
It is possible to simulate the behaviour of components and systems, on the basis of the operating conditions which can be monitored directly on the panel or through Personal Computer by teacher and students.
The Personal Computer constantly keeps under control the simulation in progress and displays its behaviour through analog and digital signals and meters; in this way the student, through measurements and tests, can go on with the troubleshooting.
TECHNICAL DESCRIPTION
The refrigerating cycle with liquefactible gas evaporation /compression is composed of the following main elements:
• Hermetic compressor
• Ventilated condenser
• Tank for the liquid
• Automatic thermostatic valve
• Ventilated evaporator
• Regulation thermostat
• Safety pressure switch
• Refrigerating fluid temperature/pressure test‐points
• Possibility to test the main alternative refrigerating fluids, such as: R‐125 alternative to R‐502, R‐134a alternative to R‐11 and R‐12, R‐407C alternative to R‐ 22
The temperature absorption/diffusion refrigerating cycle, based on a solution of water‐ammonia with inert gas (hydrogen), is composed of the following main elements:
• Aggregate consisting of boiler, water separator, condenser, evaporator, exchanger, absorber
• Electrical resistance for the boiler heating
• Regulation thermostat for electrical resistance insertion
• Solar power system composed of photovoltaic panels, block diode, battery, for the conversion of solar energy into electrical power and subsequent storage in the battery
• Electronic device for insertion/disconnection of photo‐voltaic panels, on the basis of the battery loading status • Possibility to simulate the various operating situations on the basis of the battery loading status, the temperatures and the regulations

DL TM01

DOMESTIC REFRIGERATING SYSTEMS

The simulator allows the study, the performing of experiments and the troubleshooting for the following systems:
• Single temperature domestic refrigerator
• Two temperatures domestic refrigerator
• Domestic freezer
These systems are reproduced on the panel, through a colour representation which allows a complete analysis of the fluid circuit, of its components and of the electrical/electronic circuit for control and regulation.
TRAINING OBJECTIVES
It is possible to simulate the behaviour of components and systems, on the basis of the operating conditions which can be monitored directly on the panel or through Personal Computer by teacher and students.
The Personal Computer constantly keeps under control the simulation in progress and displays its behaviour through analog and digital signals and meters; in this way the student, through measurements and tests, can go on with the troubleshooting.
TECHNICAL DESCRIPTION
The single temperature domestic refrigerator is composed of the following main elements:
• Hermetic compressor with thermal protection and intensity relay without starting condenser
• Static condenser
• Capillary pipe for refrigerating fluid expansion
• Natural air circulation static evaporator
• Regulation thermostat
• Refrigerating fluid temperature/pressure test‐points
• Possibility to simulate and test both the version for temperate climate and the version for tropical climate
The two temperatures domestic refrigerator is composed of the following main elements:
• Hermetic compressor with thermal protection and intensity relay with starting condenser
• Static condenser
• Capillary pipe for refrigerating fluid expansion
• Natural air circulation static evaporator for refrigerator
• Constant pressure valve
• Natural air circulation static evaporator and electrical defrosting resistance, for freezer
• Double regulation thermostat for refrigerator/freezer
• Refrigerating fluid temperature/pressure test‐points
• Possibility to simulate and test both the 1, 2 and 3 star freezer and the 4 star freezer
• Possibility to simulate and test both the version for temperate climate and the version for tropical climate

DL TM02

REFRIGERATING UNIT FOR FOOD DISTRIBUTION

The simulator allows the study, the performing of experiments and the troubleshooting for the following systems:
• Natural air circulation cabinet
• Forced circulation 5‐level refrigerated cabinet
• Island for frozen food
• Mixed cold cabinet
These systems are reproduced on the panel, through a colour representation which allows a complete analysis of the fluid circuit, of its components and of the electrical/electronic circuit for control and regulation.
TRAINING OBJECTIVES
It is possible to simulate the behaviour of components and systems, on the basis of the operating conditions which can be monitored directly on the panel or through Personal Computer by teacher and students.
The Personal Computer constantly keeps under control the simulation in progress and displays its behaviour through analog and digital signals and meters; in this way the student, through measurements and tests, can go on with the troubleshooting.
TECHNICAL DESCRIPTION
The natural air circulation cabinet is composed of the following main elements:
• Hermetic compressor with thermal protection and intensity relay
• Static condenser
• Automatic thermostatic valve
• Natural air circulation static evaporator
• Regulation thermostat
• Refrigerating fluid temperature/pressure test‐points
• Possibility to check the level of the temperature inside the cabinet
The 5‐level refrigerated cabinet is composed of the following main elements:
• Hermetic compressor with thermal protection and intensity relay
• Static condenser
• Automatic thermostatic valve
• Forced air circulation static evaporator
• Regulation thermostat
• Refrigerating fluid temperature/pressure test‐points
• Possibility to check the level of the temperature inside the cabinet
The island for frozen food is composed of the following main elements:
• Hermetic compressor with thermal protection and intensity relay with starting condenser
• Forced air cooling condenser
• Automatic thermostatic valve
• Forced air circulation static evaporator
• Regulation thermostat
• Defrosting resistor controlled by a counting device
• Refrigerating fluid temperature/pressure test‐points
• Possibility to check the level of the temperature inside the cabinet

DL TM03

INDUSTRIAL COLD STORE

The simulator allows the study, the performing of experiments and the troubleshooting for the following systems:
• Positive temperature store for food refrigeration and preservation
• Cold store for the preservation of frozen food
These systems are reproduced on the panel, through a colour representation which allows a complete analysis of the fluid circuit, of its components and of the electrical/electronic circuit for control and regulation.
TRAINING OBJECTIVES
It is possible to simulate the behaviour of components and systems, on the basis of the operating conditions which can be monitored directly on the panel or through Personal Computer by teacher and students.
The Personal Computer constantly keeps under control the simulation in progress and displays its behaviour through analog and digital signals and meters; in this way the student, through measurements and tests, can go on with the troubleshooting.
TECHNICAL DESCRIPTION
The positive temperature store for food refrigeration and preservation is composed of the following main elements:
• Three‐phase motor compressor group
• Waste water condenser
• Automatic thermostatic valve
• Forced convection evaporator operated by a three‐phase motor
• Electro valve for the liquid
• Defrosting resistance battery
• Regulation thermostat
• Defrosting thermostat
• Safety thermostat
• Low pressure switch
• High pressure switch
The cold store for the preservation of frozen food is composed of the following main elements:
• Three‐phase motor compressor group
• Water condenser, supplied by a water thermostatic valve
• Automatic thermostatic valve
• Forced convection air refrigerator evaporator (three‐ phase fan)
• Electro valve for the liquid
• Defrosting resistance battery
• Discharge and dripping resistance
• Motorized pendulum for defrosting control
• Visual and sound alarm device
• Regulation thermostat
• Defrosting thermostat
• Safety thermostat
• Low pressure switch
• High pressure switch

DL TM04

REFRIGERATION TRAINER

It consists of an air conditioning system, a refrigeration system, a control panel, a unit for detecting the pressure, a connection area, etc.
The air conditioning system is composed of:
Internal and external heat exchanger, compressor, 4‐way valves, control valves, etc.
The refrigeration system is composed of:
Refrigerator compressor, condenser, evaporator, regulator, thermostat, 2‐way 3‐position filter valve, etc.
The control panel is composed of:
Single‐phase ac power supply. AC voltmeter, range: 0 ~ 250V. AC ammeter, range: 0 ~ 10A. Two digit thermometer. Switch to control the main supply current.
Block diagram of the air conditioning system and of the refrigeration system. Test points. Protection against overheating or overload of the compressor.
The detection of the pressure consists of:
Four vacuum manometers used to supervise the pressures in the air conditioning and refrigeration systems.
Range: ‐0.1 ~ 1.8MPa and ‐ 0.1 ~ 3.8MPa.
Connection area:
For the control of the electric circuit of the air conditioning and refrigeration systems, for the training of the students.
SPECIFICATIONS
• Power supply: single‐phase from mains.
• Ambient temperature: ‐10 °C ~ 40 °C, relative humidity <85%, altitude < 4000 m.
• Power: <1.5kVA.
Protection against overvoltage

DL TMAC11

INDUSTRIAL REFRIGERATING SYSTEMS

Two-side simulator for the study of several industrial refrigerators and cold stores for food cooling and freezing.
- SIDE A simulates four types of industrial refrigerators: island for frozen food, natural air circulation cabinets, mixed cooling cabinets and 5 levels forced circulation cabinets.
The components that are studied in the above systems include: hermetic compressor, evaporator, thermostat, temperature/ pressure measurement test-points, etc.
- SIDE B simulates two types of industrial cold stores: positive temperature store for food refrigeration and preservation and cold store for the preservation of frozen food.
The components that are studied in the above systems include: three-phase compressor, evaporator, thermostats, defrosting resistance, pressure switches, measurement test-points, etc.
The panel is complete with CAI software.

DL TM32

COLD ROOM

With this system, students can study and analyze the phenomena of the industrial refrigeration.
This system integrates all the main components that can be found in a cold room facility.
This system is composed of modular components and can reach freezing temperatures as low as -30°C.
TRAINING OBJECTIVES
With this equipment, students can perform several experiments in the following knowledge areas:
• Heat transfer and thermal insulation.
• Refrigeration cycles of vapor compression.
• Refrigerant fluids.
• Calculation of thermal loads.
• Psychrometric processes (low temperature).
• Cold stores and industrial refrigeration.
• Automatic control and instrumentation.
TECHNICAL DESCRIPTION
The test bench consists of: a refrigeration chamber with a forced flow evaporator fed by thermostatic expansion valve, a 250W condenser unit and a transparent heated access panel.
The refrigerator circuit is equipped with:
• Flow display.
• Heat exchanger with solenoid valve.
• Electric defrost system.
• Control system via PLC and programmable timing functions.
• Drier filter and liquid storage tank.
The use of separate controls allows the simulation of different malfunctions.
The anti water hammer protection in the compressor system ensures reliable operation under extreme conditions.
The steam overheated can be regulated by the thermostat valve settings.

DL DKF011

HEAT PUMP MODULE

The system can clearly demonstrate the operation of a heat pump air/water.
The system consists of: compressor, circulation pump, flow control valve, accumulator tank, condenser, filter/drier, expansion valve and evaporator fan, water flow meters, temperature and pressure sensors with display in strategic points of the circuit.
TRAINING OBJECTIVES
• Study of the operation of a heat pump.
• Study of the main components of the heat pump.
• Representation of reversible thermodynamic processes.
• Monitoring temperatures and pressures in the process.
• Use of accumulated heat.
• Energy balances:
- Open circuit.
- Closed circuit.
TECHNICAL DESCRIPTION
With this comprehensive training equipment, students can study the utilization of environmental energy used to heat water.
The refrigerant absorbs the ambient heat while passing through the evaporator fan, and subsequently, it is transferred to the water in the condenser.
The hot-water storage tank includes an internal heat exchanger, which can be connected also to the network, in order to exchange energy with the flow of tap water.
The heat, absorbed by the water in the condenser, turns into the hot-water storage tank, where this heat energy can be exchanged with tap water flow.
The system is also ready to operate in a open circuit: the mains water can enter directly the condenser providing instantaneous heating.
TECHNICAL DATA
• Compressor: output power 400W.
• Condenser: tubular heat exchanger.
• Fin evaporator fan.
• Hot water circulation through recirculation pump.
• Hot water storage tank with internal heat exchanger, capacity: 5.5

DL DKC031

Download Area

ProductsCodeCatalogueTender specsManuals SimpleVideo
REFRIGERATING CYCLES SIMULATOR DL TM01
DOMESTIC REFRIGERATING SYSTEMS SIMULATORDL TM02
REFRIGERATING UNIT FOR FOOD DISTRIBUTION SIMULATORDL TM03
INDUSTRIAL COLD STORE SIMULATORDL TM04
REFRIGERATION TRAINERDL TMAC11
INDUSTRIAL REFRIGERATING SYSTEMSDL TM32
COLD ROOMDL DKF011
HEAT PUMP MODULEDL DKC031