AG-327 Unit, is a complete laboratory unit for the demonstration of absorption refrigeration.This unit will allow the familiarization of the students with the principles of refrigeration absorption system in use today. Absorption refrigeration systems are typically used in applications that require lower power usage such as refrigeration in recreational vehicles, domestic refrigerators, etc. Due to their easy adaptability to operate using either electricity or fuelgas, they are useful inremote locations where the supply of electricity is not readily available, and can be easily adapted to LPG, solar power, etc.This unit is provided with a dual power source (heat source) of LPG and electricity. A pressure regulator to adapt the gas to the corresponding inlet pressure is supplied for the operation with LPG (30-50 mbar). The fluid used in the refrigeration cycle of the ag-327 unit is a solution of water and ammonia (NH ), being the ammonia the refrigerant and the3 water the absorbent. An important advantage is that these agents are totally innocuous for the environment. The cycle makes use of the great affinity of the ammonia with the water, being the ammonia used as a cooling agent since it is easily absorbed by water. The unit has a generator or heater, where the water and ammonia solution is heated at a high pressure. Two substances are separated then by boiling: on one hand, vapour with a high concentration of ammonia, called concentrated solution, and on the other hand, a liquid solution with alow concentration of ammonia, called diluted or poor solution. Vapour passes through a condenser (finned exchanger) where it is cooled until is condenses and it passes to liquid state, reducing its temperature. This ammonia concentrated solution enters a heat exchanger, where it is further cooled and its pressure is reduced to enter into the evaporator. Due to this pressure difference, it is evaporated at a low temperature. The unit includes a tank for the absorber, where the solution rich in ammonia in liquid state formed by the absorber and the ammonia vapour from the evaporator stay together.The absorber makes it possible to obtain a low pressure in the evaporator so that the refrigerant (ammonia) boils at a lower temperature, taking the
required heat from the water, reducing its temperature.The liquid solution rich in ammonia coming from the absorber is heated in the generator with the aim of separating the pure ammonia vapours and the water (absorber). Ammonia vapours go to the condenser and the poor solution goes to the absorber, where the absorptionof the ammonia in vapour state is generated again.As a result, by using the AG-327 unit, students will familiarize with each of the individual components of an absorption refrigeration unit (freezing andcooling) and will have the possibility of selecting the heat source between an electrical resistance or LPG.You can know at any time the measurement of:
The temperature in the absorber, evaporator and condenser.
The temperature at the absorber's tank inlet.
The temperature at the refrigeration tank.
The room temperature.
The power consumed by the electrical resistance. Measurement of voltage and current.
This Computer Controlled Unit is supplied with Computer Control System (SCADA), and includes: The unit itself + a Control Interface Box + a Data Acquisition Board + Computer Control and Data Acquisition Software Packages, for controlling the process and all parameters involved in the process
1.- Demonstration of the refrigeration process.
2.- Demonstration of the vapour absorption refrigeration cycle and visualization of the most important processes.
3.- Familiarisation with the individual components of the absorption refrigeration unit.
4.- Operation of a gas absorption refrigeration unit using either electricity or LPG as the heat source.
5.- Comparison of the refrigeration temperature obtained using LPG or an electrical resistance as a heat source.
6.- Measurement of the electrical power.
7.- Influence of the electrical power in the refrigeration temperature obtained.
8.- Measurement of the temperature in the main points of the absorption refrigeration process. Additional practical possibilities:
9.- Sensors calibration. Other possibilities to be done with this Unit:
10.- Many students view results simultaneously. To view all results in real time in the classroom by means of a projector or an electronic whiteboard.
11.- Open Control, Multicontrol and Real Time Control. This unit allows intrinsically and/or extrinsically to change the span, gains; proportional, integral, derivate parameters; etc, inreal time.
12.- The Computer Control System with SCADA allows a realindustrial simulation
13.- This unit is totally safe as uses mechanical, electrical and electronic, and software safety devices.
14.- This unit can be used for doing applied research.
15.- This unit can be used for giving training courses to Industries even to other Technical Education Institutions.
16.- Control of the AG-327 unit process through the control interface box without the computer.
17.- Visualization of all the sensors values used in the AG-327 unit process.