Gas Fired Chillers

Gas absorption refrigeration units.

Description

Yazaki appliances are gas-fired and use an absorption cycle to produce refrigerated water.

The fluid used is a lithium bromide solution and water and is chemically stable, non-inflammable, atoxic, ecologically clean, and ozone-friendly.

The solution is preloaded into the appliances in the factory, where they are sealed and tested for immediate use.

The chilled water is produced at a temperature of 7 °C, the ideal level for air conditioning premises.

Product Line

MODEL	COOLING POWER (kW)
CH KG 30	105
CH KG 40	141
CH KG 50	176
CH KG 60	211
CH KG 80	281
CH K 100	352
CH MG 150	527
CH MG 200	703

FEATURES

A step control makes it possible to keep the multiple-unit yazaki units’ performance high, stabilising operation according to the required heat load. A modular microprocessor constantly monitors the load factor and automatically selects the optimum number of units in operation.
Yazaki units are fitted with fully waterproof cladding panels whose surfaces are treated to withstand even the most aggressive atmospheric forces.
The units typically use water evaporation towers to reject heat.
The basic models in the range cover ratings ranging from 105 to 703 refrigerating kW are of modular design, and are inter-compatible, thus making it possible to design systems with multiples of the basic ratings.
Yazaki units are certified in accordance with the EU directives.

ADVANTAGES

Very Low Electricity Consumption

The primary energy used is thermal. Electricity is used only to run the auxiliary control, fluid circulation, and heat exhaust appliances. No electricity transformation cabin is thus required.
Outdoor Installation

Yazaki appliances are designed for outdoor installation, even at locations, such as coastal and industrial sites, where the atmosphere is particularly aggressive. Utility rooms to house the refrigeration plant are no longer required. The units can, nevertheless, be installed indoors, merely taking account of the current regulations governing heat generators. Yazaki units are a particularly good choice when converting old oil-fired systems, as they free up utility room space.
Ease of Installation

Yazaki units are extremely compact. Their modular design facilitates handling and installation operations. All the units are pre-charged with lithium bromide solution and tested at the factory. Start-up operations are thus very simple and rapid and prevent any of the solution from being given off into the environment.

High Reliability

The high reliability for which absorption units of the Yazaki type are widely renowned is due to their limited number of moving mechanical parts. The very simplicity of design of such appliances is in itself a guarantee of reliability, as is certified by the ASHRAE (American Society of Heating, Refrigeration, and Air-Conditioning Engineers).
No Noise

Being fully sound-proofed, Yazaki units are extremely quiet and vibration-free. They are ideal for installation in conurbations as well, on solar flooring, on terraces, in attics, in gardens and in the courtyards of premises built for trading, industrial, and service businesses.
Low Maintenance

The small number of moving mechanical parts cuts down the number of components subject to wear and tear, and therefore requiring inspection and replacement.
Low Environmental Impact

Yazaki units do not uses CFC’s or HCFC’s, which are extremely damaging to the environment and have now been banned. The type of fuel used, gas, also reduces harmful fuel emissions.

OPERATING PRINCIPLE

High-Temperature Generator

The gas burner heats the dilute lithium bromide and water solution contained in the high-temperature generator and the boiling process propels the refrigerant vapour, which is rich in droplets of medium-concentration lithium bromide solution, into the main separator. The lithium bromide solution is collected and precooled, by being passed through a heat exchanger, prior to being fed into the low-temperature generator.
Low-Temperature Generator

The hot refrigerant vapour discharged by the separator reheats (dual effect) the medium-concentration lithium bromide solution in the low-temperature generator. The refrigerant vapour then moves on to the condenser, while the concentrated lithium bromide solution thus obtained is also precooled by the heat exchanger prior to moving on to the absorber.
Condenser

The refrigerant vapour reaches the condenser, where it condenses on the surfaces of the chilling circuit coils. The condensation heat is removed by the cooling water and exhausted through the evaporation tower. The refrigerant liquid collected in the condenser is then fed into the evaporator.
Evaporator

The influence exerted by the absorber makes the pressure inside the evaporator substantially lower than the generator and condenser pressure. Once inside the evaporator, the refrigerant liquid thus boils and absorbs heat, evaporating on the surface of the coil in the circuit containing the water to be chilled. The refrigerant vapour thus obtained then flows into the absorber.

Absorber

The low pressure in the absorber is due to the chemical affinity between the concentrated lithium bromide solution supplied by the separator and the refrigeration vapour that forms in the evaporator. The refrigerant vapour is absorbed by the concentrated lithium bromide solution as the latter bathes the surface of the absorber coil. The condensation and dilution heat is drawn off by the cooling water. The dilute lithium bromide solution is then preheated in the heat exchanger prior to being returned to the generator.

Ciclo Assorbitore a Gas Yazaki