FR2694338A1 - Cooling device for a heat engine fitted with a condenser. - Google Patents

Abstract

A three-way thermostatic valve () allows a fraction of the flow of coolant leaving the engine (1) of a vehicle, a decreasing function of the temperature of the fluid, to bypass the condenser (2). In addition, a second thermostatic valve (36) with progressive closing, when the three-way valve is in its position forcing the fluid in liquid phase to pass through the condenser, still allows a certain quantity of fluid to pass out of it. ci so that the fluid returned to the engine and passing through a heating radiator (17) is at a temperature sufficient to ensure efficient heating of the vehicle interior.

Description

Cooling device for a heat engine fitted with a condenser

  The invention relates to a device for cooling a heat engine, comprising a condenser for a coolant capable of circulating in the liquid phase and in the vapor phase, a fluid circulation pump and a vessel.

expansion.

  A device of this kind is known, in which a separation

  phase separator separates the liquid phase and the vapor phase from the fluid leaving the engine, the vapor phase being sent to the condenser to be condensed and cooled and the liquid phase being directed to the expansion vessel and from there

  returning to the engine without passing through the condenser.

  The fluid cooled by this known device, before entering the engine, passes through a heating radiator, at least when it is necessary in winter to heat the passenger compartment of the vehicle When the engine load is high and the fluid leaving it is almost entirely in the vapor phase, this fluid is condensed and cooled in the condenser to a temperature which may be too low for

  allow sufficient heating of the passenger compartment.

  The object of the invention is to remedy this drawback, while maintaining the modulation of the heat flow given off by the cooling fluid in the condenser in

depending on the engine load.

  The invention relates in particular to a device of the kind defined in the introduction, further comprising a thermostatic valve with

  three-way controlled by fluid temperature, function-

  between a first position and a second position in which, respectively, the fluid in the liquid phase

  from the motor avoids the condenser, for temperatures

  lower crossings, and crosses it, for temperatures

  tures pls high, said three-way valve being associated with a second thermostatic valve capable of deviating from the condenser a fraction, decreasing function of the temperature of the fluid, of the flow of fluid admitted by that of

  three-way valve which is connected to the condenser.

  The adjustment of the three-way valve allows a fraction of the fluid to flow through the condenser all the more

  great that the temperature of it is higher Cepen-

  In this case, there is always a fraction of the fluid which does not pass through the condenser, thus avoiding excessive cooling, either that the three-way valve is out of its second position, or whether it is in this position and

  that the second thermostatic valve in turn deflects a part

tie the fluid out of the condenser.

  Other characteristics, complementary or alternative, of the device according to the invention are set out below: It comprises a starting pipe for bringing the fluid leaving the engine to a single inlet of the three-way valve, an inlet pipe going from a first outlet of the three-way valve, closed for the lowest temperatures, to an inlet of the condenser, an outlet pipe connecting an outlet of the condenser to the motor, and a first branch pipe connecting a second outlet of the three-way valve, closed for the highest temperatures,

to the outlet pipe.

  The pump is mounted in the outlet line, downstream of

  the branch of the first bypass line.

  The inlet pipe and the outlet pipe lead respectively into an inlet chamber and into a chamber

  condenser outlet, and the second thermostat valve

  that is mounted in a second bypass pipe connecting said inlet chamber to the outlet pipe, in

  upstream of the junction of the first branch line

  tion. It includes a degassing pipe leading into the

  expansion tank and connected to the first bypass line

  tion. Other characteristics and advantages of the invention

  will appear on examining the detailed description below,

  and attached drawings, in which Figures 1, 2 and 3 are diagrams showing the configuration of a device

  cooling according to the invention for different temperatures

cooling fluid.

  The same elements are represented in the three figures,

  and they are designated by the same reference numbers.

  The cooling device illustrated is intended to cool the heat engine 1 of a motor vehicle. It uses a cooling fluid which circulates between the engine 1 and a condenser 2 filled with this fluid, the latter entering the engine in liquid phase by a inlet 3 and emerging through an outlet 4, if necessary at least partially in the vapor phase, depending on the conditions of

engine operation.

  A line 5 brings the fluid from the outlet 4 to a single inlet 6 of a three-way thermostatic valve 7 A line 8 connects a first outlet 9 of this valve to an inlet 10 of the condenser which opens into a chamber

  inlet 11 After possible condensation in the conden-

  the fluid leaves it through an outlet 12 opening into an outlet chamber 13 A pipe 14 connects the outlet 12 to a circulation pump 15 A pipe 16 brings the liquid from the pump 15 to the inlet 3 of the engine through a

  passenger compartment heating radiator 17 A water exchanger

  oil 18, used for cooling the lubricating oil

  tion of the motor 1, is interposed on a pipe 19 which is

  branched between line 16 and line 5.

  The flow of fluid produced by the pump 15 is therefore shared between a fraction passing through the motor 1 and a fraction

passing through the exchanger 18.

  A line 20 starts from a second outlet 21 of the valve

  three-way thermostatic and connects to line 14.

  The valve 7 comprises a shutter member 22 which moves, as a function of the temperature of the fluid, between two extreme positions, namely a first position illustrated in FIG. 1, in which it closes the outlet 9, and a second position illustrated in Figure 3, in which it

closes exit 21.

  The inlet chamber 11 of the condenser also has an outlet 34 from which a pipe 35 is connected to the pipe 14 In this pipe 35 is interposed a valve

  thermostatic 36, which is fully open at low temperatures

  erasing and which gradually closes when the temperature

fluid increases.

  During the cold start of engine 1, the coolant

  dissement which comes out is at low temperature, and the shutter member 22 of the three-way valve is in its first position closing the inlet 11 The fluid cannot circulate in the condenser and passes entirely through the

  outlet 21 of the three-way valve and in line 20.

  This position is maintained, in the example described, up to a temperature of 950 C, thus allowing heating

engine speed.

  Between this temperature and that of 1020 C, which roughly corresponds to the boiling temperature of the fluid, the shutter member 22 is in an intermediate position, as shown in FIG. 2 A fraction of the flow of fluid leaving the motor, increasing function of the temperature of this fluid, leaves the three-way valve through outlet 9 in line 8, crosses the condenser and out through line 14, the remaining fraction passing through outlet 21 and

  line 20, which regulates the temperature

  ture of the fluid passing through the radiator 17 and entering the engine. Finally, when the temperature is above 102 ° C, which corresponds to a high engine load and the arrival of

  fluid in vapor phase at the three-way valve and at the condensate

  sor, the shutter member 22 closes the outlet 21 of the valve 7, so that all of the fluid enters the inlet chamber 11 of the condenser However, as long as the thermostatic valve 36 is not fully closed, part of this fluid leaves the chamber 11 through the outlet 34, without having yielded a significant amount of heat, and flows in the pipe 35 This fluid mixes in the pipe 14 with the fluid in liquid phase leaving the chamber 13 of the condenser and reheating it somewhat, which makes it possible to maintain sufficient efficiency for the heating radiator 17. In practice, the pipe 35 and the thermostatic valve 36

  can be integrated into the bulkhead of condenser 2.

  The illustrated device also comprises an expansion tank 23 having a variable internal volume thanks to a deformable membrane 24, this internal volume containing coolant in the liquid phase 25 The expansion tank is connected by a degassing pipe 26 to the line 20, and via a return line 28 to line 14, these lines 2-6 and 28 being lower than the expansion tank When the outlet 21 of the three-way valve is open, the air which can be mixed with the fluid leaving the engine can rise by

  line 26 and assemble at 29 in the interior volume

  laughing of the expansion tank, above the liquid 25 Closing the outlet 21 at high temperature prevents the

  passage of fluid in vapor phase to the expansion tank.

  The device also comprises, in a manner known per se, a thermoswitch 30 placed on the pipe 14 to control, as a function of the temperature, a fan unit 31 intended to accelerate the circulation of cooling air through the condenser 2, a thermoswitch 32 placed on line 5, near outlet 4 of the engine, to signal an abnormally high temperature, and a liquid level detector 33 mounted on the bottom of the expansion tank 23 and suitable for providing a signal when it does not contain no liquid, indicating that the amount of fluid in the

  cooling system is insufficient.

Claims (4)

Claims   1 Cooling device for a heat engine (1),   comprising a condenser (2) for a coolant   suitable for circulation in liquid and vapor phase,   a fluid circulation pump (15) and an expansion tank   sion (23), characterized in that it further comprises a three-way thermostatic valve (7) controlled by the temperature of the fluid, operating between a first   position and a second position in which, respectively-   ment, the fluid in liquid phase coming from the engine avoids the condenser, for the lowest temperatures, and crosses it, for the highest temperatures, said three-way valve being associated with a second clean thermostatic valve (36) to deviate a fraction from the condenser, a decreasing function of the fluid temperature, of the fluid flow admitted by that (9) of the valve tracks   three-way which is connected to the condenser.   2 Device according to claim 1, characterized in that it comprises a starting pipe (5) for bringing the fluid leaving the engine to a single inlet (6) of the three-way valve, an inlet pipe (8) going from a first outlet (9) of the three-way valve, closed for the lowest temperatures, to an inlet (10) of the condenser, an outlet pipe (14,16) connecting an outlet (12) of the condenser to the engine, and a first bypass line (20) connecting a second outlet (21) of the three-way valve, closed for the highest temperatures, to the outlet pipe.   3 Device according to claim 2, characterized in that the pump is mounted in the outlet pipe, downstream   of the branch of the first bypass line.   4 Device according to one of claims 2 and 3,   characterized in that the inlet pipe and the outlet pipe respectively open into an inlet chamber (11) and into an outlet chamber (13) of the condenser, and that the second thermostatic valve (36) is mounted in a second bypass line (35) connecting said inlet chamber to the outlet line, upstream of the branch of the first bypass line.   Device according to one of claims 2 to 4, characterized in that it comprises a degassing pipe   (26) opening into the expansion tank and connected to the first bypass line.