Lpg Gas Refregration System.pptx

Project Group No:-

Academic Year:-2018-19 Project Title:-

LPG GAS REFRIGERATION SYSTEM

Group Member:- AMAN YUNUS SHAIKH

Group Member:-

AFTAB SHAIKH

Group Member:-

AKSHAY JADHAV

Group Member:- OMKAR JAGTAP

PROJECT GUIDE:Name:- PURVA .H. KADAM

LPG REFREGIRATION • INTRODUCTION:• In India, more than 80% of the domestic refrigerator utilize HFC 134a as refrigerant, due to its excellent thermodynamic and thermo physical properties. But,HFC 134a has a high global warming potential (GWP) of 1300. There is a need of assess various refrigerant option considering the existing refrigerators in the field and for the future market.

LPG consists mainly of propane (R-290) and butane (R-600), and LPG is available as a side product in local refineries. In Cuba for already several decadesLPG is used as a drop-in refrigerant. LPG mixtures have composition of a commercialLPG mixture suitable as ‘drop-in’ replacement for R-12 was calculated crudely as64% propane and 36% butane by mass. Liquefied petroleum gas (LPG) of 60% propane and 40% commercial butane has been tested as a drop-in suitable for R 134ain a single evaporator domestic refrigerator with a total volume of 10 ft3.The revival of LPG refrigerants in domestic and small commercial application in happy accident (Vidal 1992). Engineers had known since the 1920’s that LPGrefrigerants performed well and in the 1980s refrigerators manufacturers again tested them (Kuijpers et al. 1988). Fear of a flammability campaign from the chemical industry deterred any manufacture. In march 1989, the Institute of Hygiene in Dortmund Germany needed a new cold storage room. The young idealistic director, Dr Harry Rosin, could not consider using a CFC refrigerant and so tried propane and iso butane. Greenpeace Australia imported a For on refrigerator in February 1993 and in December 1993 Email Ltd, Australia’s largest appliance manufacturer, displayed prototype LPG refrigerators. In 1994, German manufacturer announced one by one their intention of switch to LPG refrigerants.OZ Technology Inc, a start up company in Idaho, introduced OZ-12 a mixture of commercial propane and butane in 1992. they sold over 50,000 170 g cans the first summer. The Mobile Air-Conditioning Society made flammability hazard claims including ‘a bomb in the passenger compartment’ (Keebler 1993, MACS 1993). Thus EPA refused to approve OZ-12 on flammability grounds. The USEPA may not approve this either but OZ’s petition (OZ 1994) is convincing, comprehensive and technically sound especially on safety. Color released Care 30 injure 1994.

PROPERTIES • »Colorless. • » Odourless. (It’s normal to odorise LPG by adding anodorant prior to supply to the user, to aid the detectionof any leaks). • »Flammable. • » Heavier than air. • » Approximately half the weight of water. • » Non toxic but can cause asphyxiation. • » LPG expands upon release and 1 litre of liquid will form approximately 250 litresof vapour •

SOME IMPORTANT DEFINATIONS A good mixture : LPG is mainly Propane (C3H8), Butane (C4H10) or a mix of Propane/Butane. Since LPG has such a simple chemical structure, it is among the cleanest of any alternative fuel. Boiling point : LPG’s boiling point ranges from -42 ºC to 0 ºC depending on its mixture percentage of Butane and Propane.

Combustion : The combustion of LPG produces carbon dioxide (CO2) and water vapour but sufficient air must be available. Inadequate appliances flueing or ve ntilation can result in the production of carbon monoxide which can be toxic Vapour pressure: LPG is a stored as a liquid under pressure. It is almost colourlessand its weight is approximately half that of an equivalent volume of water. The pressure inside a closed container in which LPG is stored is equal to the vapour pressure of the liquid and corresponds to its temperature.

Ignition temperature: The temperature required to ignite LPG in air is around 500ºC Calorific value: The calorific value of LPG is about 2.5 times higher than that of main gas so more heat is produced from the same volume of gas. Toxicity : LPG is a colorless, odorless and non-toxic gas. It is supplied commercially with an added odorant to assist detection by smell.LPG is an excellent solvent of petroleum and rubber product and is generally on-corrosive to steel and copper alloys. Safety : LPG is just as safe as any other fuel. In fact, it is safer than most fuels because neither LPG itself nor the end products that are produced by burning LPG in suitable appliance, are poisonous to inhale. Since LPG cannot burn without air, there can never be a ‘Flash-back’ into the cylinder. You can feel safe with LPG as the most through precaution are taken tonsure your safety. All you have to do is to handle it correctly whilst adhering to the simple instructions provided.30

APPLICATION Application of LPG as refrigerant that divides in two categories: 1.Processes that uses LPG

2.Industries that uses LPG

THE LPG REFRIGERATION CYCLE 1). LPG Gas

Cylinder:

From the LPG gas cylinder, LPG flows through the pipe and reaches to the capillary tube. LPG gas pressure is approximate 80-100 psi. (2). Capillary

Tube:

As the capillary tube, capillary tube downs the pressure up to less then 1 psi. (3). Evaporator:

In the evaporator LPG is converted into the vapour from with low pressure. After passing through the evaporator low pressure and temperature LPG vapour absorbs heat from the chamber system. (4). Gas

Burner:

After performing the cooling effect, low pressure LPG gas goes into the burner where the burns.

PARTS OF REFRIGERATORS LPG Gas Cylinder:LPG is Liquefied Petroleum Gas. This is general description of Propane (C3H8) and Butane (C4H10), either stored separately or together as a mix. This is because these gases can be liquefied at a normal temperature by application of a moderate pressure increases, or at normal pressure by application of LPG using refrigeration. LPG is used as a fuel for

domestic, industrial, horticultural, agricultural, cooking, heating and drying processes. LPG can be used as an automotive fuel or as propellant for aerosol, in addition to other specialist ap plications. LPGcan also be used to provide lighting through the use of pressure lanterns.

Capillary Tube:The capillary tube is the commonly used throttling device in the domestic refrigeration.

The capillary tube is a copper tube of very small internal diameter. It iso very long length and it is coiled to several turns so that it would occupy less space. The internal diameter of the capillary tube used for the refrigeration applications varies from 0.5 to 2.28 mm(0.020 to 0.09 inch). The capill ary tube is shown in picture. When the refrigerant enters in the capillary tube, its pressure drops down suddenly due to very small diameter. The decrease in pressure of the refrigerant through the capillary depends on the diameter of capillary and the length of capillary. Smaller is the diameter and more is the length of capillary more is the drop in pressure of the refrigerant as it passes through it.

Evaporator:The evaporators are another important parts of the refrigeration systems. It through the evaporators that the cooling effect is produced in the refrigeration system.

It is in the evaporators when the actual cooling effect takes place in the refrigeration systems. For many people the evaporator is the main part of the refrigeration system, consider other part as less useful. The evaporators are heat exchanger surface that transfer the heat from the substance to be cooled to the refrigerant, thus removing the heat from the from the substance. The evaporators are used for wide variety of diverse application in

designs. They are also classified in different manner depending on the method of feeding the refrigerant, construction of the evaporator, direction of air circulation around the evaporator, application and also the refrigerant control. the large refrigeration plants the evaporator is used for chilling water. In such cases shell and tube type of heat exchanger are used as the evaporators. In such plants the evaporators are classified as: (1). Dry expansion type of evaporators (2). Flooded type of the evaporators

The evaporators are classified based on the construction as: (1). Bare tube evaporators (2). Plate surface evaporators (3). Finned evaporators (4). Shell and tube evaporator (5). Shell and coiled evaporator, (6). Tube-in-tube evaporator

The evaporators are classified based on mode of heat transfer (1). Natural convection evaporator, (2). Forced convection evaporator

Pressure gauges:Many techniques have been developed for the measurement of pressure and vacuums. Instruments used to measure pressure are called pressure gauges or vacuum gauges.

A manometer could also referring to a pressure measuring instrument, usually limited to measuring pressures near to atmospheric. The term manometer is o ften used to refer specifically to liquid column hydrostatic instruments.

High Pressure pipes:The range of high pressure pipes covers most application where there is require ment to transfer gas at high pressure. They consist of a steel pipe with steel ball fitted to both end. Two swiveling connection nipples press these balls against the seating of the connecting hole and thus sealing against gas leakage.

» Wide range of pipes.» All pipes are pressure tested to 100 M Pa (14,500 psi) over recommended working pressure.

CONSTRUCTION OF THE LPG REFRIGERATOR •

The LPG refrigerator shown in figure. We make the one box of the plywood. The plywood sheet size is 12mm for used the LPG refrigerator. The size of the refrigerator is 724*457*381 mm3. The evaporator is fitted on the upper portion of box inside. Inside the refrigerator, we also put the thermo-coal sheet, because of the cold air cannot the transfer from inside to outside of refrigerator.

The schematically diagram of the LPG refrigeration system is shown in next page. The gas tank is connect by pipes to the capillary tube. The capillary tube is fitted with evaporator. The evaporator coiled end is connect to the stove by another gas circulation pipe. When two pressure gauge is put between capillary tube and gas tank, and another is put the end of the evaporator.

WORKING LPG REFRIGERATOR

The basic idea behind LPG refrigeration is to use the evaporation of a LPG to absorb heat. The simple mechanism of the LPG refrigeration working is shown in figure

LPG is stored in the LPG cylinder under high pressure. When the gas tank of regulators is opened then high pressure LPG passes in gas pipe. This LPG is going by high pressure gas pipe in capillary tube .» High pressure LPG is converted in low pressure at capillary tube with enthalpy remains constant.

» After capillary tube, low pressure LPG is passed through evaporator. LPG is converted into low pressure and temperature vapour from and passing through the evaporator which absorbs heat from the chamber. Thus the camber becomes cools down. Thus we can achieve cooling effect in refrigerator. » After passing through the evaporator low pressure LPG is passed through pipe by burner. And we can uses the low pressure of LPG is burning processes.

ADVANTAGE OF LPG:The advantages of LPG are as follows

:» Clean burning.

» Effects of corrosions are greatly reduced. » Instantly control the flame temperature. » Avoids scaling and decarburising of parts. » Environmentally friendly fuel, with minimal sulphur content and sulphurfree emissions. » Very high efficiency with direct firing system instant heatfor faster warm-up and cool-down. » LPG is easily liquefied and stored in pressure containers. Itcan be easily transported in cylinder or tanks.

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