CN110234863A - regenerative cooling system - Google Patents

Abstract

A regenerative cooling system (100) is provided for regenerative heat engine (1) and comprises a cooling chamber (79) surrounding a gas expander (78) between said chamber (79) and said A gas circulation space (80) is reserved between the expanders (78), and the working gas (81) discharged from the gas expander (78) circulates in said space (80) before being returned to the regenerative heat exchanger (5), In the regenerative heat exchanger the working gas is cooled and most of the heat of the gas (81) is reintroduced into the thermodynamic cycle of the regenerative heat engine (1).

Description

regenerative cooling system

The present invention relates to a regenerative cooling system constituting, inter alia, an improvement of a transfer-expansion and regenerative heat engine of patent application dated 25.02.2015 belonging to the applicant No. FR 15 51593 and also the subject of the applicant's patent number US 2016/0252048 A1 published on September 1, 2016.

The Brayton regeneration cycle, usually implemented with the aid of centrifugal compressors and turbines, is familiar.

According to this mode of embodiment, said cycle causes the engine to provide a significantly higher efficiency than that of a controlled ignition engine. Said efficiency is comparable to that of a fast diesel engine. However, it is still smaller than that of very large displacement low speed two-stroke diesel engines such as found in marine propulsion or stationary power generation.

In addition to very modest overall efficiencies, centrifugal compressor and turbine engines using the Brayton regeneration cycle offer optimum efficiency over a relatively narrow range of power and rotational speeds. Furthermore, their response time in power modulation is long. For these various reasons, their fields of application are limited, and they are difficult to adapt to land transportation, especially cars and trucks.

The transfer-expansion and regenerative heat engine of patent application No. FR 15 51593 has been proposed to remedy these disadvantages. The special feature of the described engine is that the regenerative Brayton cycle is no longer implemented with the aid of centrifugal compressors and turbines, but with the aid of volumetric machines or at least with the aid of volumetric expanders formed around the "expander cylinder" Brayton cycle.

In the drawings of patent application No. FR 15 51593 it is noted that each end of said expander cylinder is closed by an expander cylinder head. In addition, the cylinder houses a double-acting expander piston to form two variable volume transfer-expansion chambers. The piston is displaceable in the expander cylinder to transfer work to the PTO shaft via the familiar connecting rod and crankshaft.

One of the advantages claimed by the invention which is the subject of patent application No. FR 15 51593 is the efficiency with which heat is successfully converted, said efficiency being much higher than that of alternative conventional internal combustion engines of any working principle, which means that the same work provides This results in a lower fuel consumption than said conventional engine and also reduces the associated carbon dioxide emissions.

In order to achieve these goals, at least three conditions need to be fulfilled, as clearly stated in patent application FR 15 51593 .

The first is that volumetric expanders actually consist of a single cylinder, which is not the teaching of the prior art involving such machines. As an example, patent US2003/228237 A1 of December 11, 2003 does include a compressor, a regenerative heat exchanger, a heat source, and an expander, however the expander is not a cylinder, but what the inventor of said patent calls a "cycloidal ".

The second condition is that the gas inlet and outlet in the expander cylinder are regulated by properly phased intake and exhaust metering valves, which results in a pressure versus volume diagram as shown in the diagram in patent application No. FR 15 51593 .

The third condition is that the seal between the piston and cylinder can operate at very high temperatures.

It should be noted that the transfer-expansion and regenerative heat engine described in patent application No. FR 15 51593 satisfies said third condition by proposing an innovative air cushion segment made of continuously perforated inflatable and inflatable A ring is formed which sits in an annular groove designed in the expander piston. The ring and the groove together define a pressure distribution chamber connected to a source of pressurized fluid.

This new seal without direct contact with the expander cylinder makes it possible to operate the cylinder at high temperature while closing the intake and exhaust metering valves in the cylinder head of said cylinder maximizes the efficiency of the transfer-expansion and regenerative heat engine become possible.

The innovative sealing device based on air cushion segments is intentionally placed in patent application No. FR 15 51 593 in the claims dependent on the independent claim. It is easy to understand that, by presenting his invention in this way, the inventor does not exclude other sealing solutions that could replace said segment, even though the latter is mentioned in said patent application as a key element of a transfer-expansion and regenerative heat engine propose.

As clearly stated in patent application FR 15 51593, in order for the transfer-expansion and regenerative heat engine to be as efficient as possible, the inner walls of the expander cylinders need to be raised to a high temperature so that the hot gases introduced into said cylinders The walls are not cooled, or at least cooled by those walls as little as possible. This applies at least to the inner wall of the expander cylinder, as well as the inner wall of the cylinder head cooperating with said cylinder.

According to the principles of engine thermodynamics proposed by Sadi Carnot, patent application FR 15 51593 proposes that the efficiency of transfer-expansion and regenerative heat engines increases with the higher temperature of the gas introduced into the expander cylinder.

That is why patent application FR 15 51593 requires the expander cylinder, the cylinder head of the expander cylinder and the expander piston of the transfer-expansion and regenerative heat engine to be made of very high temperature resistant materials such as ceramics based on alumina, zircon or silicon carbide )production.

The hot parts and thermal components at high temperature of transfer-expansion and regenerative heat engines are also the subject of patents for improvements of said engines. Reference may therefore be made to the patent application No. FR 15 58585 dated September 14, 2015 belonging to the applicant, which relates to double-acting and adaptive support expander cylinders capable of operating at high temperatures and subjected to different Thermal expansion due to thermal expansion of the gearbox to which it is attached. In the same respect, attention should also be paid to patent application No. FR 15 58593 of September 14, 2015, also belonging to the Applicant, which relates to a double-acting piston consisting of a prestressed assembly and capable of operating at temperature.

Note that the patent applications No.FR 15 58585 and No.FR 15 58593 just cited propose very robust solutions for the presence of high temperature and low temperature parts in the same equipment.

In particular, the configuration proposed in said patent largely prevents the migration of heat from the hot parts to the cold parts with which they cooperate. This ensures increased efficiency of the transfer-expansion and regenerative heat engines.

On the other hand, the improvements proposed in patent applications No. FR 15 58585 and No. FR 15 58593 do not change the fact that if the temperature of the gas introduced into the expander cylinder of the engine is, for example, 1300 degrees Celsius, the cylinder The temperature of the inner walls will be locally close to 1300 degrees Celsius, wherein the average temperature of these walls is close to eg 1000 degrees Celsius.

The temperature of these gases therefore directly determines the temperature to which the materials making up the hot parts of the expander cylinder of the transfer-expansion and regenerative heat engine must withstand. Thus, indirectly, the temperature resistance of these materials determines the maximum available efficiency of the engine.

Furthermore, it should be noted that the number of materials in question capable of withstanding very high temperatures is relatively small, as they also need to provide increased mechanical strength at these same temperatures, while also being resistant to corrosion and oxidation.

The materials are mainly ceramics, such as alumina, zircon, silicon carbide or silicon nitride. These materials are hard and difficult to machine. Consequently, the relative increase in the selling price of finished parts prevents the automotive industry from adopting the transfer-expansion and regenerative heat engine described in patent application FR 1551593. In fact, since the industry in question is geared towards the consumer market, it is very sensitive to manufacturing sales prices, which need to be as low as possible.

Therefore, it is desirable that the expander cylinder inner wall of the engine be maintained at a maximum temperature of, for example, 700°C to 900°C. In fact, at this temperature, more common materials, such as cast iron or stainless steel or refractory materials, which are less expensive to produce and process than ceramics, can be used to manufacture the expander cylinder. The same is true for the cylinder heads and their corresponding plenums and ducts cooperating with said cylinders.

However, on the one hand the temperature reduction of the hot gases admitted to the expander cylinders of the transfer-expansion and regenerative heat engine must be prevented and on the other hand the heat of these gases must be allowed to pass as a pure loss through the cooler walls of the cylinders in contact with these gases escape. In fact, these two actions can have the detrimental consequence of significantly reducing the ultimate efficiency of the transfer-expansion and regenerative heat engine.

In the current state of the art, therefore, there is a choice between transfer-expansion and regenerative heat engines, which are very efficient but expensive and difficult to produce, and engines based on the same principles but made of materials that are less expensive to produce but have greatly reduced efficiency. This poses a conundrum.

To address this challenge, in a particular embodiment, the regenerative cooling system of the present invention allows:

Significant reduction of the inner wall temperature of the expander cylinders and their cylinder heads of the transfer-expansion and regenerative heat engine which is the subject of patent application FR 15 51593, making it possible to manufacture said cylinders and these cylinder heads using lower sales price materials without would significantly reduce the overall efficiency of said heat engine;

· Enabling higher temperature gas to enter expander cylinders of expensive and complex materials such as ceramics without the regenerative cooling system according to the invention;

• The use of low selling price materials to provide the transfer-expansion and regenerative heat engine which is the subject of patent application FR 15 51593 a higher final energy efficiency than is possible for the same engine with expensive and complex materials such as ceramics.

It will be understood that the regenerative cooling system according to the invention is primarily aimed at the transfer-expansion and regenerative heat engine belonging to the applicant and being the subject of patent application FR 1 551 593 .

However, the system can also be applied without limitation to the expander of any other engine having a Brayton regeneration cycle, whether the expander is a centrifuge, positive displacement expander or any other type of expander, provided that It works with any given type of regenerator.

Other characteristics of the invention have been described in the description and in the dependent claims which are directly or indirectly dependent on the independent claim.

The regenerative cooling system according to the invention is designed for a regenerative heat engine comprising at least one regenerative heat exchanger having a high-pressure regeneration duct in which the working gas circulates to preheating, the working gas has been pre-compressed by the compressor, while at the outlet of the pipe, the gas is superheated by a heat source before being introduced into the gas expander, where the The gas expands to do work on the PTO shaft, then the gas is expelled at the outlet of the gas expander and introduced into the low pressure regeneration piping of the regenerative heat exchanger where it circulates by Release most of its residual heat to the working gas circulating in the high-pressure regeneration pipeline, the system includes:

· at least one cooling chamber completely or partially surrounding said gas expander and/or heat source and/or hot gas inlet duct connecting said source to said expander, while in one aspect said chamber and/or on the other hand retaining a gas circulation space between said expander and/or said source and/or said pipeline;

· At least one chamber inlet port connected directly or indirectly to the outlet of the gas expander and through which some or all of the working gas expelled from the expander via the outlet can pass entering said gas circulation space;

• At least one chamber outlet port connected directly or indirectly to the low pressure regeneration conduit and through which the working gas can leave the gas circulation space before being introduced into the low pressure conduit.

The regenerative cooling system according to the invention comprises a chamber inlet port connected to the outlet of the gas expander by a chamber inlet pipe whose effective cross-section is adjusted by a flow control valve.

The regenerative cooling system according to the present invention comprises a chamber outlet port connected to a low pressure regeneration pipe by a chamber outlet pipe, the effective cross-section of which is adjusted by a flow control valve.

The regenerative cooling system according to the invention comprises an outlet of the gas expander connected to a low pressure regeneration conduit through a chamber bypass conduit.

The regenerative cooling system according to the invention comprises an effective cross-section of the chamber bypass duct regulated by a flow control valve.

The regenerative cooling system according to the invention comprises the exterior of the cooling chamber coated with a thermal insulation layer.

The following description with respect to the attached drawings and given as non-limiting examples will allow a better understanding of the invention, its characteristics and the advantages it can offer:

Figure 1 is a schematic side view of a regenerative cooling system according to the invention, such as may be implemented in a transfer-expansion and regenerative heat engine belonging to the applicant and being the subject of patent application No. FR 15 51593, and According to a variant of said system, whereby the outlet of said gas expander is connected to said low-pressure regeneration conduit via a chamber bypass conduit such that the effective cross-section of said bypass conduit and chamber outlet conduit is controlled by a flow control valve adjust.

Detailed ways:

A regenerative cooling system 100 , various details of its components, its variations, and its accessories are shown in FIG. 1 .

As shown in FIG. 1, a regenerative cooling system 100 is provided for a regenerative heat engine 1, which includes at least one regenerative heat exchanger 5 having a high-pressure regenerative pipeline 6, the working gas 81 at a high pressure Circulates in the regeneration duct 6 , is heated in said duct and has previously been compressed by the compressor 2 .

When leaving the high pressure regeneration conduit 6 , the gas 81 is superheated by the heat source 12 before being introduced into the gas expander 78 where the gas expands to produce work on the PTO shaft 17 .

Then, the working gas 81 is discharged from the gas expander 78 and introduced into the low-pressure regeneration pipe 7 of the regeneration heat exchanger 5, and said gas 81 releases a large amount of its residual heat to the high-pressure regeneration by circulating in said pipe 7. The working gas 81 circulating in the pipeline 6.

In said context, shown clearly in FIG. 1 , the regenerative cooling system 100 according to the invention comprises at least one cooling chamber 79 completely or partially surrounding the gas expander 78 and/or the heat source 12 and/or the hot gas inlet line 19 connecting said source 12 to an expander 78, while on the one hand said chamber 79 and/or on the other hand said expander 78 and/or said source 12 and /Or a gas circulation space 80 is reserved between the pipes 19 , and the working gas 81 can circulate in the space 80 .

It should be noted that the cooling chamber 79 may be made of drawn or hydroformed stainless steel sheet and that it may be realized in multiple parts assembled to each other by welding, screwing or riveting, after which the chamber may be directly or indirectly Attaches to the part 78, 12, 19 it surrounds.

FIG. 1 shows that the regenerative cooling system 100 according to the present invention also includes at least one chamber inlet port 82 connected directly or indirectly to the gas expander outlet 78 and from which Some or all of the working gas 81 exhausted by the expander 78 may enter the gas circulation space 80 through the chamber inlet port 82 .

Also, in FIG. 1, it should be noted that the regenerative cooling system 100 according to the present invention also includes at least one chamber outlet port 83, which is directly or indirectly connected to the low-pressure regeneration pipe 7, and the working gas 81 may leave the gas circulation space 80 through the chamber outlet port 83 before being introduced into the low pressure conduit 7 .

It should be noted that cooling chamber 79 preferably surrounds gas expander 78 and/or heat source 12 and/or hot gas inlet conduit 19 in a tight manner such that working gas 81 can enter gas circulation space 80 only through chamber inlet port 82 , even though the gas 81 can leave the space 80 only through the chamber outlet port 83 .

According to a variant embodiment of the regenerative cooling system 100 according to the present invention as shown in FIG. The cross section is regulated by a flow control valve 85 capable of preventing, allowing or restricting the circulation of the working gas 81 in said conduit 84 according to its position.

As another variant, again as shown in FIG. 1 , the chamber outlet port 83 may be connected to the low-pressure regeneration pipe 7 through a chamber outlet pipe 86 whose effective cross-section is regulated by a flow control valve 85, which 85 is capable of preventing, allowing or restricting the circulation of working gas 81 in said chamber outlet duct 86 depending on its position.

Figure 1 also shows another variant of the regenerative cooling system 100 according to the invention, in that the outlet of the gas expander 78 can be connected to the low-pressure regeneration conduit 7 via a chamber bypass conduit 87 which allows The working gas 81 discharged from the outlet of the gas expander 78 flows directly from the outlet to the low-pressure regeneration pipe 7 without moving through the gas circulation space 80 .

According to said latter variant, the effective cross-section of the chamber bypass duct 87 can optionally be adjusted by a flow control valve 85 which, depending on its position, prevents, allows or restricts the flow of the working gas 81 in said bypass duct. Loop in 87.

In FIG. 1 , it should be noted that the exterior of the cooling chamber 79 may advantageously be coated with an insulating layer 88 which may be formed of any insulating material known to those skilled in the art, and that in addition to the cooling chamber 79 In addition, the insulating layer 88 can also coat the various heat pipes and elements making up the regenerative heat engine 1 .

It should be noted that in this case said insulating layer 88 is provided in order to prevent any excessive heat loss detrimental to the efficiency of the regenerative heat engine 1 .

Function of the present invention:

The function of the regenerative cooling system 100 according to the present invention will be readily understood by considering FIG. 1 .

In order to describe this functionality, we shall use here an example embodiment of a regenerative cooling system 100 according to the invention (when applied to a regenerative engine 1 of said regenerative cooling system as patent application of 25.02.2015 belonging to the applicant as Transfer of the subject of No. FR 15 51593 - when composed of expansion and regenerative heat engines).

As can be seen in FIG. 1 , the regenerative engine 1 here comprises a two-stage compressor 2 , which in particular consists of a low-pressure compressor 35 which draws in working gas from the atmosphere via the compressor inlet duct 3 81 , the outlet of the low-pressure compressor 35 is connected to the inlet of the high-pressure compressor 36 via the intermediate compressor cooler 37 .

Figure 1 shows that at the outlet of the high-pressure compressor 36, the working gas 81 is discharged into the high-pressure regeneration line 6 comprising the regeneration heat exchanger 5, which in this case is a counter-flow heat exchanger known per se. switch 41. It should be assumed here that the working gas 81 is discharged from the high-pressure compressor 36 at a pressure of 20 bar and a temperature of 200 degrees Celsius.

By circulating in the high-pressure regeneration pipe 6 , the working gas 81 is preheated to a temperature of 650 degrees Celsius by the hot working gas 81 circulating in the adjacent low-pressure regeneration pipe 7 .

For simplicity we will consider the efficiency of the regenerative heat exchanger 5 to be one hundred percent. This means that the working gas 81 circulating in the low-pressure regeneration conduit 7 enters the low-pressure regeneration conduit 7 at a temperature of 650 degrees Celsius and leaves said conduit 7 at a temperature of 200 degrees Celsius before being discharged into the atmosphere via the engine outlet conduit 33, Whereas the working gas 81 circulating in the high-pressure regeneration pipeline 6 enters the high-pressure regeneration pipeline 6 at a temperature of 200 degrees Celsius and exits at a temperature of 650 degrees Celsius.

On leaving the high-pressure regeneration conduit 6 , said working gas 81 is then superheated to 1400 degrees Celsius by a heat source 12 , which according to this example embodiment consists of a fuel burner 38 .

On leaving said burner 38, the working gas 81 is directed through the hot gas intake duct 19 to the gas expander 78, which is in fact the expander cylinder 13 of the transfer-expansion and regenerative heat engine, the expander The actuator cylinder 13 is the subject of patent application No. FR 1551593.

It should be noted that the hot gas intake duct 19 is preferably made of high temperature resistant ceramic up to its connection with the cover of the expander cylinder 14 , thereby covering one end or the other of the expander cylinder 13 . Thus, the temperature of said duct 19 is kept approximately equal to 1400 degrees Celsius, so that the working gas 81 circulating in said duct 19 maintains its temperature throughout its course.

Thus, as shown in FIG. 1 , each end of the expander cylinder 13 is capped by an expander cylinder head 14 so as to define two transfer-expansion chambers 16 with a double-acting expander piston 15 . It should also be noted that each cylinder head has an intake metering valve 24 and an exhaust metering valve 31 .

Due to the regenerative cooling system 100 according to the invention, the transfer-expansion and regenerative heat engine is hot, and the cylinder heads of the expander cylinder 13 and expander cylinder 14 are maintained at a temperature close to seven hundred degrees Celsius. This makes it possible to construct the cylinder 13 and the cylinder head 14 from cheaper and more common materials than ceramics, such as stainless steel or ferritic iron.

For the double-acting expander piston 15, and according to this non-limiting example of the regenerative cooling system 100 of the present invention, the double-acting expander piston 15 is made of silicon nitride. The average working temperature of the piston 15 is about 800 degrees Celsius.

It should be noted in FIG. 1 that said piston 15 is connected to the power take-off shaft 17 by means of a mechanical transmission 19 consisting in particular of a connecting rod 42 articulated to a crank 43 .

Thus, working gas 81 at a pressure up to 20 bar and at a temperature up to 1400° C. is introduced into one or the other transfer-expansion chamber 16 through the corresponding inlet metering valve 24 .

Through the orifice held open by the inlet metering valve 24, the gas 81 begins to cool slightly, especially in contact with the inner walls of the cover of the expander cylinder 14 and the inner walls of the transfer-expansion chamber 16 through which it passes, for There expanded by the double-acting expander piston 15 , the gas 81 is introduced into the transfer-expansion chamber 16 . The walls are maintained at 700 degrees Celsius by the regenerative cooling system 100 as described above.

At this point we will assume that the working gas 81 loses an average of 100 degrees Celsius by washing the inner walls of the cover of the expander cylinder 14 and the walls of the transfer-expansion chamber 16 . Consequently, the temperature of the working gas 81 has dropped during its passage from the hot gas inlet duct 19 to the transfer-expansion chamber 16, moving from 1400 to 1300 degrees Celsius.

When the required quantity of working gas 81 has been effectively introduced into the transfer-expansion chamber 16 by the corresponding intake metering valve 24 , the latter is closed and the double-acting expander piston 15 expands said gas 81 . In doing so, the piston 15 collects the work produced by said gas 81 and transmits it to the PTO shaft 17 , notably via the connecting rod 42 and the crank 43 .

Once the working gas 81 has been expanded by the double-acting expander piston 15, the pressure of said gas 81 has dropped by about 1 bar absolute. The same is true for the temperature of this gas 81, which has changed from 1300 degrees Celsius to 550 degrees Celsius.

The double-acting expander piston 15 has reached its bottom dead center, the exhaust metering valve 31 is open, and the piston 15 expels the gas 81 into the chamber inlet conduit 84 which discharges the gas 81 leads to chamber inlet port 82.

The working gas 81 then enters the gas circulation space 80 and is guided to the chamber outlet port 83 via said space. In doing so, the gas 81 diffuses over the hot outer walls of the expander cylinder 13 and the cylinder head of the expander cylinder 14 . The outer walls are designed to be fully or partly roughened and/or interspersed with geometric patterns in order to create forced convection when the gas 81 is in contact with these walls and circulate, so that the working gas 81 is more or less carried away from the walls heat.

Furthermore, the internal geometry of the cooling chamber 79 and/or the external geometry of the expander cylinder 13 and/or the external geometry of the cylinder head of the expander cylinder 14 may advantageously form channels which force all or some of the working gas 81 follows the path or several simultaneous paths from the chamber inlet port 82 through the gas circulation space 80 to the chamber outlet port 83 .

It will be appreciated that the dual strategy of forced convection and forced path of the working gas 81 makes it possible firstly to select the areas for exporting heat from the hot outer walls of the cylinder heads of the expander cylinder 13 and expander cylinder 14 to said gas 81 and secondly The chronological order in which said areas are swept by said gas 81 is selected, and thirdly and finally the intensity of the forced convection along the path of said gas 81 .

In any event, during the travel of the working gas 81 in the cooling chamber 79, the temperature of the working gas 81 extracts heat from the hot outer walls of the cylinder heads of the expander cylinder 13 and expander cylinder 14 to a temperature of the gas 81 from 550 The degrees Celsius gradually change to a point of 650 degrees Celsius. In doing so, and in combination with the strategy of forced convection and routing chosen for the working gas 81, the gas homogenizes the temperature of the expander cylinder 13 and the cylinder head of the expander cylinder 14, which are maintained at around 700 degrees Celsius.

The working gas 81 has reached its new temperature of 650 degrees Celsius, the gas 81 reaches the chamber outlet port 83 and returns to the low pressure regeneration pipe 7 via the chamber outlet pipe 86 .

As can be understood from the foregoing description, the working gas 81 discharged from the chamber outlet port 83 releases most of its heat to the adjacent The working gas 81 circulating in the high-pressure regeneration pipeline 6 .

Finally, and thanks to the regenerative cooling system 100 according to the invention, the heat extracted from the cylinder heads of the expander cylinders 13 and 14 to maintain them at a temperature of about 700 degrees Celsius is never dissipated as a pure loss.

In effect, the heat is reintroduced into the regenerative heat engine 1 thermodynamic cycle to replace part of the heat that needs to be provided by the fuel burner 38 , so that the working gas 81 is sent to the expander cylinder 13 and subsequently introduced into the transfer-expansion chamber 16 Before, the working gas 81 was brought to a temperature of 1400 degrees Celsius.

In FIG. 1 it should be noted that the chamber bypass line 87 has a flow control valve 85 . It should also be noted in FIG. 1 that the chamber outlet conduit 86 also has a flow control valve 85 . These two valves 85 constitute a variant embodiment of the regenerative cooling system 100 according to the invention and are provided for regulating the temperature of the cylinder heads of the expander cylinder 13 and the expander cylinder 14 .

In fact, if the temperature is too high, the flow control valve 85 of the chamber bypass line 87 blocks said bypass line 87 while the flow control valve 85 of the chamber outlet line 86 opens said outlet line 86 . This has the effect of forcing the working gas 81 exhausted from the transfer-expansion chamber 16 through their respective exhaust metering valve 31 to move through the gas circulation space 80 and back into the low pressure regeneration conduit 7 .

On the other hand, if the temperature of the cylinder head of the expander cylinder 13 and expander cylinder 14 is too low, the flow control valve 85 of the chamber bypass line 87 opens the bypass line 87 while the flow control valve of the chamber outlet line 86 85 closes the outlet duct 86 . This has the effect of preventing the working gas 81 exhausted from the transfer-expansion chamber 16 by their respective exhaust metering valve 31 from moving through the gas circulation space 80 to return to the low-pressure regeneration conduit 7 . The gas 81 is thus returned directly to the conduit 7 via the chamber bypass conduit 87 .

It will be appreciated that in practice the flow control valve 85 is rarely fully open or fully closed and that said valve 85 may be left slightly open to regulate the temperature of the cylinder head of the expander cylinder 13 and expander cylinder 14 without sudden The flow rate of the working gas 81 circulating in the gas circulation space 80 is changed.

It should also be understood that the regulation of said temperature requires control means, for example consisting of at least one temperature sensor and a microcontroller, which are known per se and which enable the control of any type of servo motor such that each A motor actuates the flow control valve 85 to open or close.

According to a particular embodiment of the regenerative cooling system 100 according to the invention, the flow control valves 85 may also be connected together by a mechanical linkage to share the same servo motor. In this case, the linkage ensures that when the first valve 85 is closed, the second valve is open, and vice versa.

From the foregoing description it can be easily concluded that the regenerative cooling system 100 according to the invention brings many advantage.

As a first advantage, it is no longer necessary to manufacture the cylinder heads of the expander cylinder 13 and the expander cylinder 14 from a ceramic material such as silicon carbide. In fact, this material is known to be expensive to produce due to its hardness, making it difficult to process with conventional cutting or grinding tools. Thanks to the regenerative cooling system 100 according to the invention, it is possible to replace this ceramic with cast iron or stainless steel. This significantly reduces the manufacturing and selling price of transfer-expansion and regenerative heat engines, which is decisive, especially for such engines to be able to enter the automotive market.

As a second advantage, since the cylinder heads of the expander cylinders 13 and 14 are cooler, it is possible to use materials with very low thermal conductivity and high compressive strength, such as quartz, to manufacture The hollow strut of a double-acting expander cylinder, which is the subject of patent application No. FR 1558585 of 14 September 2015 belonging to the applicant. In fact, while quartz is not compatible with temperatures of 1300 degrees Celsius, quartz is perfectly compatible with temperatures of 700 degrees Celsius. Remember that the discussed double-acting expander cylinder with adaptive support is one of the key improvements in transfer-expansion and regenerative heat engines.

As a third advantage, since the cylinder heads of the expander cylinders 14 are maintained at 700 degrees Celsius, they can use pre-existing silicon nitride valves that are compatible with these temperature levels. For example, such valves were developed by the company NGK and have been the subject of research on their low-cost industrialization, in particular the G3RD-CT-2000 entitled "LIVALVES" funded within the framework of the fifth European FP5-GROWTH program - in the context of item 00248.

As a fourth advantage, in case the temperature of the inner wall of the expander cylinder 13 is maintained in the vicinity of 700 degrees Celsius, the air cushion segment proposed in the patent application No. FR 15 51593 belonging to the applicant can be made durable against these temperature levels superalloy without the risk of the segments being subjected to temperatures significantly above 700 degrees Celsius, especially when the transfer-expansion and regenerative heat engine is stopped and before it cools down.

As a fifth advantage, applied to the transfer-expansion and regenerative heat engine that is the subject of patent application No. FR 15 51593, the regenerative cooling system 100 according to the invention makes it possible to confine the cylinders surrounding the expander cylinder 13 and the expander cylinder 14 The temperature exposure of the thermal insulation layer 88 of the cover. In fact, the cooling chamber 79 is interposed between these partitions 88 on the one hand and the cylinder 13 and the cylinder head on the other hand. Accordingly, the selling price and durability of the barrier 88 are largely improved.

These advantages are obtained without compromising the ultimate energy efficiency of the transfer-expansion and regenerative heat engine.

On the contrary, the regenerative cooling system 100 according to the invention enables the existing relationship according to the patent application No. FR 15 51593 to enable on the one hand the temperature resistance of the materials constituting the cylinder heads of the expander cylinder 13 and the expander cylinder 14 and on the other hand There is a decoupling between the temperature of the working gas 81 leaving the fuel burner 38 on the one hand.

To some extent, thanks to the regenerative cooling system 100 according to the invention, it is conceivable to increase the temperature of the working gas 81 leaving the fuel burner 38 in order to increase the ultimate efficiency of the transfer-expansion and regenerative heat engine, and this does not impair the composition The temperature stability of the main components of the engine.

It should be noted that, in addition to the transfer-expansion and regenerative heat engine that is the subject of patent application No. FR 15 51593, the regenerative cooling system 100 according to the invention can be advantageously applied to a system whose construction and temperature characteristics are compatible with said system 100 Any other regenerative heat engine1.

Therefore, the possibilities of the regenerative cooling system 100 according to the invention are not limited to the application just described, and it is also understood that the foregoing description is given only as an example and in no way limits the scope of the invention, by substitution by any other equivalent implementation details are described without departing from the scope of the described invention.

Claims (6)

1. re-generatively cooled system (100) of the one kind designed for regeneration Thermal Motor (1), the regeneration Thermal Motor include At least one regenerative heat exchanger (5), the regenerative heat exchanger have high-pressure regeneration pipeline (6), and working gas (81) is in institute It states and is recycled in high-pressure regeneration pipeline to preheat wherein, the working gas is compressed by compressor (2) in advance, while in institute The exit of pipeline (6) is stated, the gas (81) is overheated before being introduced into gas expander (78) by heat source (12), described Gas expansion described in gas expander on power output shaft (17) to do work, and then the gas (81) is swollen in the gas The exit of swollen device (78) is discharged and is introduced into the low pressure regeneration pipeline (7) of the regenerative heat exchanger (5), the gas (81) its most of after-heat is released in the high-pressure regeneration pipeline (6) and the circulation in the pipeline (7) Circulation the working gas (81), the system (100) be characterized in that comprising:

At least one cooling chamber (79), fully or partially around the gas expander (78) and/or heat source (12) And/or the source (12) are connected to the hot gas admission line (19) of the expander (78), while the chamber on the one hand Retain gas between room (79) and/or the another aspect expander (78) and/or the source (12) and/or the pipeline (19) The cyclic space (80)；

At least one chamber inlet port (82), be directly or indirectly connected to the gas expander (78) it is described go out Mouthful, and institute can be passed through from the expander (78) via some or all described working gas (81) of the outlet discharge Chamber inlet port is stated into the gas circulation space (80)；

At least one chamber outlet port (83) is directly or indirectly connected to the low pressure regeneration pipeline (7), and institute The gas can be left by the chamber outlet port before being introduced into the low pressure pipeline (7) by stating working gas (81) The cyclic space (80).

2. re-generatively cooled system as described in claim 1, it is characterised in that the chamber inlet port (82) is entered by chamber Mouth pipeline (84) is connected to the outlet of the gas expander (78), and the effective cross section of the chamber ingress pipeline is by flowing Control valve (85) is adjusted.

3. re-generatively cooled system as described in claim 1, it is characterised in that the chamber outlet port (83) passes through the chamber Room outlet conduit (86) is connected to the low pressure regeneration pipeline (7), and the effective cross section of the chamber outlet pipeline is by flow control Valve (85) processed is adjusted.

4. re-generatively cooled system as described in claim 1, it is characterised in that the outlet of the gas expander (78) is logical It crosses chamber bypass duct (87) and is connected to the low pressure regeneration pipeline (7).

5. re-generatively cooled system as claimed in claim 4, it is characterised in that the chamber bypass duct (87) it is effective transversal Face is adjusted by flow control valve (85).

6. re-generatively cooled system as described in claim 1, it is characterised in that the cooling chamber (79) be externally coated with every Thermosphere (88).