 Radiator Compartment.The radiator compartment is situated at the number 1 end of the locomotive. Contained within the radiator compartment are the cooler group radiators, two electric cooler group fans, the traction motor blower for No 1 bogie, fuel lift pump, air dryer, crankcase extraction fan, lubricating oil priming pump and air reservoirs. Coolant System Data:- • Coolant System Pressure Relief valve: 0.4 Bar. • Coolant System Capacity: 567Litres (124 UK Gallons). • Flow Rate at 1000 RPM: 1.75 -2.5 BAR. • Radiator Fan Motor: 30 KW @ 1,320 RPM. • Coolant Flow Rate: 84 Cubic Metres /Hour at 1000 RPM. • Air Flow: 52 Cubic Metres /Sec. • Radiator Thermal Switch No1: Closes 72°C Opens 65ºC. • Radiator Thermal Switch No2: Closes 80ºC Opens 75ºC. • High Water Temperature Switch: Closes 85ºC Opens 78ºC. The system is a closed type employing high rates of coolant flow to ensure low temperature throughout the engine water jacket, cylinder liners and cylinder head. The self contained cooler group has two AC fan motors to control the temperature. The pressure within the system is controlled by a pressure - anti-vacuum valve and circulation is by a mechanically driven pump on the free end (non alternator end) of the engine. High temperature and low level indications are provided as are safeguards to shut the engine down should the situation become critical. Coolant water is drawn from the cooler group by the engine driven pump and passed to the lubricating oil heat exchanger which is mounted on the engine "A" bank, from there it flows to the charge air cooler, the cooler has a central dividing plate, the water enters the cooler at the bottom of one side, flows up over the plate and down the other side. A bleed off pipe on the top allows a small amount of water to return to the header tank and prevents any build up of air within the cooler. On leaving the charge air cooler the water splits into two, one goes to the turbocharger and then directly back to the cooler group, this is restricted by the size of the outlet pipe. The other forms the main circuit and splits into eight branches of the coolant manifold. The manifold distributes coolant to each cylinder, coolant passes round the liner barrel then via the cylinder collar to the cylinder. From the cylinder head the coolant flows via the outlet manifold to the back to the cooler group. A further vent pipe comes from the coolant manifold to bleed water to the header tank and again ensure no air builds up within the system causing air-locks. The cooler group is connected to the engine by flexible hoses. The cooler group unit contains radiator elements, header tank, pressure relief/anti-vacuum valve, filler valve, contents gauge, low water level switch, 2x three phase AC induction fan motors and radiator shutters. No thermostatic valve is provided in the coolant system. The Radiator Elements are mounted in the roof. Radiator louvers are fitted on the upper side of the elements and are hinged on one edge, with a rubber inset on the other. The louvers overlap slightly so the seals prevent the ingress of coal dust and fly ash when the fans are not running. Further protection to prevent damage by heavier objects is given by a screen and wire mesh. Air is drawn in through the locomotive side and is forced out of the roof louvers via the radiator elements. The Radiator Fans fan motors are controlled by individual thermal switches. The switches are mounted on the outlet manifold between the engine and the cooler group. Thermal Switch No 1 closes at 72ºC to run No 1 fan and opens at 65ºC to stop it. Thermal Switch No 2 closes at 80ºC to run No 2 fan and opens at 75ºC to stop it.  A pressure relief valve and anti-vacuum valve is fitted to the
cooler group header tank to prevent excessive pressure in the
system. A low coolant level switch is also incorporated in the
header tank, if the level falls below a predetermined level, the
level relay de-energises the engine run valve and the lubricating
oil priming pump contactor, this shuts down the engine and prevents
it from being restarted until the coolant level is restored. A
coolant level indication is given on the control cubicle and a
general alarm light on the drivers desk. Standard BR Type filler
connections are provided on both sides of the locomotive.High Water Temperature protection is also provided on the locomotive. High water temperature is sensed by a thermal switch in the coolant outlet manifold. If water temperature reaches 85ºC an indication on the control cubicle is given along with a general fault light on the drivers desk. The diesel engine is returned to idling speed, when the temperature falls to 78ºC power will be available. Page Last Updated: 30th November 2008 |