FR2751276A1 - FUEL SUPPLY SYSTEM COMPRISING A FUEL TANK - Google Patents

Abstract

The invention relates more particularly to the use for heating of waste heat from fuel. For the direct use of waste heat from the fuel (3), the fuel tank (1) is designed as a heat exchanger and incorporated into the cooling circuit of the internal combustion engine. This exchanger notably has a corrugated intermediate bottom (2) between the fuel and the cooling medium (5). A variant provides for the incorporation of a fuel / water heat exchanger (8) in the fuel return line to the tank. Applicable in particular to motor vehicles in which the injected fuel is brought to a relatively high temperature.

Description

The invention relates to a fuel supply system comprising a

fuel tank for a

internal combustion engine.

  DE 37 25 881 A1 discloses a device comprising a heat exchanger for

  the temperature of the fuel brought to a combustion engine

  internal bustion. There is provision in this device at a time

  space for fuel and space for refrigeration

  of a refrigerating system. We have the possibility

  to change the fuel temperature in the way

  in order to avoid the risk of formation of vapor plugs in the fuel lines when temperatures in the engine compartment are high, or to prevent flaking of paraffin at low temperatures, in case the fuel is diesel. DE 32 31 881 A1 also discloses an internal combustion engine with a device for cooling the fuel supplied to the engine. This document provides for a heat exchanger interposed in the circuit

  cooling of an air conditioning system and

  cooling every time the system of

  air conditioning is in use. This provision is central

  increased power at full load and a

reduction of pollutants emitted.

  These devices have the disadvantage that the chain

  their lost fuel is not used and can not be used because the waste heat can be recovered in the fuel supply line

  engine fuel is far too low for an

  prosecuting. DE 32 14 874 C2 discloses a fuel supply system with a fuel tank and a refrigeration system containing a heat exchanger which serves as an evaporator for cooling fuel in the tank. This ensures that even high outside temperatures can not have a detrimental effect on the fuel at

inside the tank.

  The construction of this supply system is however very complicated since it requires in particular a refrigerating system with a refrigerant circuit acting as an intermediate buffer. The heat taken from the fuel

  is then sold outside.

  Thermal engines optimized for use

  sation do not provide enough waste heat

  by the engine cooling circuit. It is necessary

  while respecting international requirements for

  keep the windows free of fog or frost. The con-

  strong also plays an important role in a pleasant temperature in the cockpit. In order to satisfy these

  requirements, it is generally necessary to use

  auxiliary heating elements. Now these elements increase

  the price of the vehicle, although they are only necessary

  when the engine is idling or in the

warm-up phase.

  The object of the invention is therefore to create a device

  by which the heating system of a vehicle

  automobile can be perfected.

  According to the invention, this result is achieved.

  result from the fact that, for direct use

  lost heat from the fuel, the fuel tank

  rant is designed as a heat exchanger and incor-

  in the cooling circuit of the combustion engine

  internal combustion, or by the fact that a heat exchanger

  their fuel / water is incorporated in the driving of

fuel tower.

  In the case of common rail injection systems, applied more and more frequently, the fuel is put for example under a very high pressure and strongly heated by the subsequent expansion. However, the fuel found in the part

  of the injection system comprising the distribution ramp

  is not necessary in full for the combustion of

  tion. Unburned fuel whose temperature

  continues to be very high and is then returned to

  to a return line to the fuel tank. Thanks to the embodiment according to the invention of the tank as a heat exchanger and the incorporation of this exchanger in the cooling circuit of the internal combustion engine, the waste heat of the fuel is

  can be used directly to heat a motor vehicle

  bile. Instead, it is also possible to incorporate a fuel / water heat exchanger in the pipeline.

  fuel return. A combination of these two possibilities

  is also conceivable for a different exploitation

  timale of the lost heat of the fuel.

  Embodiments and developments

  advantage of the invention emerge from the example of

  the principle of which is described below in

  FIG. 1 is a section of a fuel tank according to the invention, taken along the line I-I of FIG. 2; and - Figure 2 is a section of the tank of the

  Figure 1 taken along line II-II.

  Figures 1 and 2 show a fuel tank 1 provided with an intermediate bottom 2 made as a sheet or corrugated sheet type breakwater (device used in particular in tank trucks). The tank 1 and the intermediate bottom 2 can be in

  plastic material or sheet metal.

  Fuel 3 is on one side of the bottom

  2. Fittings 4 for feeding and evacuation

  fuel 3 are arranged on both sides of the

tank 1.

  On the other side of the intermediate bottom 2, there is a coolant 5, water by

  example, which is recycled by an unrepresented water pump

  boarded the vehicle, the cooling agent

  contained in a cooling system

  usually an internal combustion engine. For the supply and discharge of the coolant 5, connectors 6 are also provided on both sides of the tank.

  The engine is equipped with an injection system -

  not shown - a distribution manifold in which the fuel is put under a high pressure. The part of

  fuel 3 not necessary for combustion is

  due, which leads to a significant warm-up, and

  to tank 1. This is where an exchange takes place

  of heat between the fuel 3 and the coolant

  5 through the intermediate floor 2.

  The intermediate bottom 2 is made so that as large a surface as possible for heat exchange is available between the fuel 3 and the agent

cooling 5.

  A fuel pump 7 is installed inside the

  tank. For this purpose, the bottom 2 is made so that the fuel pump 7 is at the lowest point in the tank 1 to allow emptying

complete of it. -

  Figure 1 shows in dotted line another pos-

  for the use of waste heat from the car-

  fuellines. A fuel / water heat exchanger 8 is

  in this case in the return line of fuel

  rant, upstream of the connection 4 through which the fuel 3 is fed to the tank 1. The exchanger 8 is integrated in the cooling circuit of the combustion engine

internal (not shown).

Claims (4)

  1. Fuel system includes   a fuel tank for an internal combustion engine, characterized in that, with a view to the direct use of the waste heat of the fuel, the fuel tank (1) is designed as a heat exchanger and incorporated in the circuit engine cooling internal combustion.   2. Fuel supply system according to   claim 1, characterized in that an intermediate   diaire (2) is arranged in the fuel tank.   3. Fuel system according to the   claim 2, characterized in that the intermediate   diaire (2) is made as a sheet or corrugated sheet breakwater type.   4. Fuel system includes   a fuel tank for an internal combustion engine, characterized in that a heat exchanger   fuel / water (8) is incorporated in the fuel tower.