MY PROJECT 1 (AIR-CONDITIONED WAGONS)

Indian Railways being one of the biggest transporters of freight and people all over the India. With significant development in technologies of Indian Railways, it has advanced coaches as LHB rakes, advanced locomotives along with HOG technologies, better tracks, safer systems etc. Inspite of all these developments, Indian Railways is still lagging behind on its freight wagons. The old, outdated wagons are still used by Indian Railways in these modern worlds causing a major loss in energy and money. These post aims in development of special type of wagons for Indian Railways which becomes very useful in transportation of different more goods.

Many different wagons as BTPN, BOXNHL, BCNA, BCCN etc. are being used by Indian Railways transporting the raw materials, petroleum, cements, grains etc. Still it becomes difficult to transport packed foods, vegetables or such items which requires cooling as there were no air-conditioned wagons present in Indian Railways. Some materials are required to be transported from North to South which usually takes 2 to 3 days and if we transport such materials, it becomes mandatory to use refrigerated wagons.

Working of refrigeration unit:

The cooling and refrigeration take place by RAC cycle. The compressor compresses the vapor from low pressure to high pressure supersaturated steam. This steam is condensed in condenser to liquid state which is throttled to low pressure by capillary tube. This low-pressure liquid is passes through evaporator causing the required cooling action. Thus, the RAC system consists of four devices- compressor, condenser, throttling device, evaporator following the reversed heat engine cycle.

Construction and working of Refrigerated wagons

The refrigeration system consists of set of 4 wagons in which the various components will be distributed as shown in the figure below:

A: compressor

B: condenser

C: throttling device

D: evaporator

The wagon 2 of the set consists of hanging compressor below it where the low-pressure steam will be converted to high pressure supersaturated steam. This steam is made to passed through the hanging condenser at wagon 3 where the steam will be converted to high pressure liquid. The condenser contains the set of cooling fans and blowers where the flowing air cools the steam to liquid. This high-pressure liquid is made to passed through the distributer where the pump distributes the coolant liquid to all four wagons equally. This coolant liquid will be received in four throttling devices attached to each wagon. The device contains the capillary tubes wounded in form of spring where the pressure of the liquid is reduced without causing any change on its enthalpy. Finally, the low-pressure liquid reaches to the evaporator containing set of zig-zag tubes all around the wagon which extracts heat from the materials kept inside the wagons and thus makes the refrigeration effect. Finally, the high temperature, low pressure liquid gets collected in collector which is then sent to the compressor and the process repeats.

A fan attached at the top of wagon makes the forced circulation inside the wagons by which the heat is extracted uniformly from the materials and cold air will be distributed uniformly.

 
Advantages of such systems

    1. Due to distributed refrigeration system, it decreases the load or weight of each wagon thus decreasing the axle load over the rails.

    2. As more of the components are attached below the wagons, it increases the carrying capacity of the wagons.

    3. As for the four wagons, only one compressor and condenser are used, this decreases the power consumptions of the wagons.

    4. The bottom portion of wagon 1 and wagon 4 are empty. This can be utilized in instalment of brake systems for the four wagons.

Power supply to the wagons

As we can see that the wagons require electricity for its working. This electricity can be supplied either by batteries or any self-generating unit attached to the wagons. But batteries cannot work for so long and charging is required at either interval. Also, the self-generation unit attached will increases the friction and more tractive effort will be required.

This problem can be solved if we also apply the technique of HOG generation in freight locomotives. As we know the HOG generation used in passengers’ locomotives to power the coaches directly by using the 25KV electric supply by the pantograph. The extra installation of HOG generation unit is to be done in the freight locomotives similar to passenger’s locomotive.

As we know that most of the freight trains will be shifted to Dedicated Freight Corridor (DFC) once the project will be completed which are completely electrified routes. Thus the HOG generation locomotives can be used for such freight wagons which will boost the economy of the Indian Railways and increases the probability of freight transportation by rails.

TEXTS: MYSELF

IMAGES: GOOGLE IMAGES