GB2027861A

GB2027861A - Cooling engine room of electric locomotive

Info

Publication number: GB2027861A
Application number: GB7924849A
Authority: GB
Original assignee: Ruhrkohle AG; Thyssen Industrie AG
Current assignee: RAG AG; ThyssenKrupp Technologies AG
Priority date: 1978-07-17
Filing date: 1979-07-17
Publication date: 1980-02-27
Also published as: DE2831343C2; DE2831343A1; FR2431384A1; GB2027861B; FR2431384B1

Abstract

An arrangement for cooling the electric and electronic power system of an electric underground mining locomotive 1, which system is accommodated in an engine room 3 enclosed by a pressure-resistant housing 4, comprises an evaporator 6 which together with a fan 7 and a driving motor 8 for the fan 7 is arranged in the engine room 3. In operation the fan 7 causes the air in the engine room 3 to be circulated by way of the evaporator so as to provide cooled air for cooling the power system in the engine room. A condenser 13, a further fan 14 with driving motor 15, and a compresser 16, which are operatively connected to the evaporator 6, are arranged outside the engine room 3 between the housing 4 and the driver's cabin 2. Two temperature sensors 9 and 9' are located in the engine room 3. The sensor 9 responds to an adjustable temperature and controls the fan motor 8 for the air circulation in the engine room 3. The sensor 9' is operative to cause the power system to be reduced or switched-off when a maximum permissible air temperature in the engine room 3 is exceeded. <IMAGE>

Description

SPECIFICATION Cooling arrangement for the electric power system housed in the engine room of an electric mine locomotive This invention relates to be cooling arrangement for the electric and electronic power system housed against fire-damp and explosion hazards in an engine room, enclosed to be pressure-resistant, of an electric mine locomotive, particularly in an underground mining locomotive driven by way of an overhead line and/or a traction battery.

The term "electric and electronic power system" used herein is intended to cover both all of the electric and all of the electronic equipment and all of the components connected thereto.

A mining locomotive driven in this manner is known, for example from the journal "Moderne Eisenbahn", Issue 9, 1970, page 1 7 and 90.

The electric installations in mine locomotives without fire-damp and explosive protection are cooled by convection or by air exchange arrangements. If the electric equipment has to be protected against fire-damp and explosions and is, therefore, subject to the regulations prescribing a pressure-resistent enclosed housing, the dissipated heat must be removed from the enclosed housing via a separate cooling unit since the temperature of the external air and the maximum permissible temperature of the air in the interior of the housing are approximately equal.

It is an object of the invention, therefore, to provide a cooling arrangement which quarantees constantly effective cooling in the enclosed engine room without the requirement for air exchange and independently of any increase in power and associated enlargement of the engine room.

Accordingly, the present invention consists in cooling arrangement for the electric and electronic power system of an electric underground mining locomotive, which system is accommodated in an engine room enclosed by a pressure-resistant housing, said arrangement comprising at least one evaporator arranged in the engine room together with a motor-controlled fan for circulating the air in the engine room through said evaporator, a condenser with a further fan and a compressor which are arranged outside the engine room and which are operatively connected to said evaporator, and two temperature sensors arranged in the engine room, of which one responds to an adjustable temperature and controls the fan-motor for the air circulation in the engine room and the other causes the electric power to be reduced or switched off when a maximum permissible air temperature in the engine room is exceeded.

A particularly suitable embodiment of the invention is that in which the evaporator with the air circulation fan and the driving motor is built into a housing forming an air duct, in such a manner that is is ready to be connected.

The driving motor of the fan can suitably be acted on by the current of cooled circulated air.

Preferably, the housing complete with evaporator, fan and motor, and forming an air duct, is arranged stationary at or in the vicinity of the inner surface of the front wall of the engine room facing the driver's cabin of the locomotive and the condenser with the fan is mounted at the outer surface of said front wall. Conveniently, the adjustable response temperature of the temperature sensor for the air circulation is approximately 303"K and the adjustable respose temperature of the temperature sensor for the power reduction or switch-off is approximately 31 3 K.

The advantage gained with the invention consist particularly in that it guarantees satisfactory cooling of the engine room and simultaneously prevents heat being radiated to the engine room walls by the electric elements because these elements are subject to a constant flow of cooled air. A further advantage of the invention lies in that the air flowing around the electric elements is returned cooled into the engine room via the shortest path.

In order that the invention may be more readily understood, reference is made to the accompanying drawing which shows diagrammatically and by way of example a longitudinal central section through a mine locomotive with the cooling arrangement according to the invention.

The illustrated locomotive 1 has, seen across the direction of travel, next to the driver's cabin 2 an engine room 3 which is enclosed by a pressure-resistant housing 4 and in which, protected against fire-damp and explosions, the electric power system is accommodated. For the purpose of installation and removal of this electric power system, and for its maintenance, the housing 4 of the engine room 3 has a plurality of lateral openings which can be closed positively by outwardly pivotable covers (not shown). The electric and electronic equipment of the electric power system consists of exchangeable assemblies which are arranged, by means of plug-ins, in the engine room 3 both in mutual spaced relationship and spaced in relation to the surfaces defining the engine room.Inside the engine room 3, preferably in the zone of the end wall 5 facing the driver's cabin 2, there is located an evaporator 6 and a fan 7 driven by a motor 8. This motor is controlled in accordance with the temperature measured inside the engine room. For this purpose a temperature ensor 9 is mounted in the engine room 3, which responds to an adjustable maximum temperature to switch on motor 8.

The temperature sensor 9 can be set, for example, to a minimum response temperature of approximately 303"K.

The engine room 3 also contains a further temperature sensor 9' which protects the installation against a maximum permissible air temperature of approximately 31 3 K being exceeded. The evaporator 6 and fan 7 with the driving motor 8 are jointly built into a housing 10 which forms an air duct. The housing 10 can be mounted in the engine room 3 as a complete assembly ready for connection. Ducts 11 and 1 2 lead from the evaporator 6 to a condenser 1 3 arranged outside the engine room 3 and having a fan 14 with its own motor 1 5. The motors 8 and 1 5 of the two fans 7 and 14 are supplied with power from the locomotive's on-board electric system.In addition to the condenser 13, a compressor 1 6 is also arranged outside the engine room 3 and operatively connected (not shown) to the condenser 1 3 and to the evaporator 6.

For cooling the engine room 3 and the electric power system located inside it, the fan 7 is caused to be switched on by the sensor 9, and this causes the circulation of air in the engine room 3. During this operation the air from the engine room 3 flows through the evaporator 6 and is then forced by the fan 7 through the outlet duct in the housing 10 into the engine room 3 where it flows around the electric power equipment and, in doing so, removes heat from the latter by heating itself, and then returns to the evaporator 6. In the drawing the air flow is indicated by arrows.

The described cooling arrangement uses as refrigerants halogenated hydrocarbons, for example dichlorodifluoromethane (Frigen 12.).

The liquid refrigerant under low pressure is evaporated in the evaporator 6 by expansion.

The evaporator lowers the temperature of the circulation air passing through the evaporator.

The compressor 1 6 draws away the remaining vapour from the evaporator, compresses it, and passes it to the condenser 13, where it parts with its heat and condenses. The low liquid refrigerant is returned to the evaporator 6 where it is again evaporated by expansion accompanied by extraction of heat from the circulation air.

The operation of the evaporator 6 in conjunction with that of the condenser 1 3 and compressor 1 6 is advantageously monitored by appropriate control devices (not shown).

Claims

1. Cooling arrangement for the electric and electronic power system of an electric underground mining locomotive, which system is accommodated in an engine room enclosed by a pressure-resistant housing, said arrangement comprising at least one evaporator arranged in the engine room together with a motor-controlled fan for circulating the air in the engine room through said evaporator, a condenser with a further fan and a compressor which are arranged outside the engine room and which are operatively connected to said evaporator, and two temperature sensors arranged in the engine room, of which one responds to an adjustable temperature and controls the fan-motor for the air circulation in the engine room and the other causes the electric power to be reduced or switched off when a maximum permissible air temperature in the engine room is exceeded.

2. Cooling arrangement according to claim 1, wherein the evaporator with the air circulation fan and driving motor is built into a housing forming an air duct for the circulated air.

3. Cooling arrangement according to claim 1 or 2, wherein the driving motor of the air circulation fan is acted on by the cooled circulated air.

4. Cooling arrangement according to claim 2 or 3, wherein the housing with the evaporator, fan and motor is arranged stationary at or in the vicinity of the inner surface of the end wall of the engine room facing the driver's cabin of the locomotive, the condenser with said further fan being mounted at the outer surface of said end wall.

5. Cooling arrangement according to any of the claims 1 to 4, wherein the adjustable response temperature of the temperature sensor for the air circulation is approximately 303"K and the adjustable response temperature of the temperature sensor for reducing and switching-off the electric power is approximately 313'K.

6. Cooling arrangement for the electric and electronic power system of an electric underground mining locomotive, substantially as herein described with reference to and as shown in the accompanying drawing.

7. Cooling arrangement for an electric and electronic power system enclosed in a fluidtight housing, comprising at least one evaporator arranged in said housing with a motorcontrolled fan for circulating the air in the housing through said evaporator, a condenser with a further fan and a compressor arranged outside said housing and operatively connected to said evaporator, and a first temperature-responsive means arranged in said housing and responding to an adjustable temperature in order to control the fan-motor for the air circulation in the housing, and a second temperature-responsive means which causes the electric power to be reduced or switched off when a maximum permissible air temperature in the housing is exceeded.