FR3051512A1 - SYSTEM FOR PRODUCING HEAT ENERGY WITH AT LEAST ONE HEAT ENERGY STORAGE STORAGE VAPOR BATTERY FROM A SOLAR INSTALLATION - Google Patents

Abstract

The present invention relates to a thermal energy system with at least one thermal energy storage vapor accumulator from a solar installation. According to the invention, the system essentially comprises at least one steam accumulator (11) connected to the outlet of the water / vapor separator tank (3) upstream of the inlet of a steam consumer ( 5), a controlled valve (15) can be opened to inject into the space of the accumulator (11) an excess of steam from the balloon (3) to pressurize the accumulator (11) and another controlled valve (18). ) can be opened when the accumulator (11) is at the pressure close to that of the balloon (3), and a pump (20) connected to the bottom of the accumulator (11) and for returning a flow rate of liquid water of this accumulator at the inlet of the steam generator (1) for maintaining a constant mass of liquid water in the steam accumulator (1). The invention finds application in the field of solar installations.

Description

The present invention relates generally to a thermal energy production system provided with at least one storage tank of thermal energy storage water vapor.

It applies in particular to a solar plant linear concentration in direct generation of water vapor to transform solar energy into thermal energy.

[0003] Such an installation is known, based in particular on the Fresnel mirror technology, and which comprises a set of mirror modules constituting primary reflectors mounted on a support structure on the ground along several lines or parallel rows, each row of mirrors comprising a series of several mirrors.

This installation further comprises linear receivers constituted by tubes supported by vertical poles so that the linear receivers extend longitudinally respectively above rows of mirrors which are oriented to reflect and focus the solar radiation to these receptors.

Each tube-shaped receiver is traversed by a heat transfer fluid generally consisting of water which is converted into vapor form by solar radiation and which can be sent to a turbo-generator set to produce electricity. . Such a solar installation thus operates in direct generation of steam.

In an industrial installation, a techno-economic optimization tends to design a solar field consisting of several rows of mirrors of a relatively large size. This has the consequence of requiring a large length of receiver tubes of large diameters as well as a large diameter piping to connect the ends of the different parallel receiver tubes disposed respectively above the parallel rows of mirrors.

Thus, the volume of water of such a solar installation can be very important and as it generally operates at high temperature, the expansion of the water volume of the solar field is also important.

Generally, a separator water / steam, also called boiler balloon, is used to resume such a dilation of the water volume of the solar field. Therefore, in an industrial solar installation, the separation balloon must therefore have a very large volume.

Moreover, the recoverable thermal power of a thermodynamic solar installation has a profile depending on the solar height, azimuth, sunshine, but also other factors such as cloud cover, for example.

The isentropic efficiency of a steam turbine depends strongly enough on its operating point. The further away from the nominal turbine load, the lower the efficiency of the turbine.

A technico-economic optimization tends to oversize the solid boiler so as to operate longer at the nominal point of the turbine, where its performance is maximum.

Therefore, the installation of a suitable thermal storage device allows to increase the electricity production by storing the surplus thermal energy during the hours when the sun is important and restoring it at night in the aim to make the solar installation more profitable.

The thermal storage device also allows continuous operation during clouding, thereby reducing operation on / off the steam turbine and reducing fatigue phenomena due to heat stress and increasing its service life.

The thermal energy storage device in a thermodynamic solar installation for the production of electrical energy is essential to make the technology mature.

As a rule, the storage by steam accumulator constituting the thermal energy storage device consists in injecting high pressure steam and high temperature into the reservoir of this accumulator containing an initial mass of cold water. In contact with cold water, the steam will condense and provide heat to the rest of the cold water. This will cause a rise in pressure and temperature of the water contained in the accumulator by following the saturation curve.

Once the pressure in the tank of the accumulator has reached the pressure of the boiler, the storage is loaded.

With operation of the installation "slippery pressure", during the lower load of the boiler, the pressure of the installation will drop, the pressurized hot water contained in the storage tank of the accumulator will vaporize instantly, restoring the previously stored heat. The steam thus produced is therefore used by the consumer of the installation constituted by the steam turbine in the context of a solar installation.

In a conventional installation comprising a storage by steam accumulator, the mass transfer is generally from the accumulator of steam to a cold reservoir during destocking and conversely in storage. The cold tank is used to store the cold water used to charge the storage tank of the steam accumulator.

As a rule, during the storage process, the water is pumped from the cold reservoir, possibly through exchangers to increase its temperature before reaching the boiler where the water is vaporized. The steam thus produced is stored in one or more steam accumulators.

This method thus requires the installation of oversized equipment and / or additional equipment used specifically for the storage device of thermal energy (tanks, pumps, exchangers ...).

The present invention aims to overcome the above disadvantages of the prior art.

For this purpose, the invention proposes a thermal energy production system, characterized in that it comprises a generator of high pressure water vapor and high temperature; a water / steam separator balloon connected at the outlet of the steam generator; a consumer of water vapor connected at the outlet of the water / steam separator tank; at least one water vapor accumulator containing liquid water and connected to the outlet of the water / vapor separator tank upstream of the inlet of the water vapor consumer via two parallel pipes respectively a first conduit leading into the accumulator of water vapor in the space above the level of the liquid water and having a controlled valve which can be opened to inject into the space of the accumulator of water vapor a surplus water vapor from the water / steam separator tank for pressurizing the water vapor accumulator to a pressure relatively close to that of the water / vapor separator tank and a second pipe opening into the liquid water in the vicinity of the bottom of the steam accumulator and having a controlled valve that can be opened when the steam accumulator is at the pressure close to that of the water / steam separator tank to inject a surplus of steam. afraid of water coming from this balloon in the liquid water of the accumulator of water vapor with increase of the temperature of the liquid water; and a pump connected to the bottom of the steam accumulator for returning a flow of liquid from the accumulator of water vapor to the inlet of the steam generator to maintain a body of water constant liquid in the water vapor accumulator during the injection of water vapor into the space and the bottom of the water vapor accumulator through the first and second pipes.

The first and second pipes respectively comprise two flow meters for measuring the flow of water vapor in these two pipes and the valve in the first pipe is controlled to control the flow of water vapor passing mainly through the valve of the second pipe and stabilize the total water vapor flow rate stored in the water vapor accumulator measured by the two flowmeters to a calculated setpoint to store all excess steam from the balloon water / steam separator.

According to an alternative embodiment, the first and second pipes respectively comprise two flow meters for measuring the flow of water vapor in these two pipes and the two valves of the first and second pipes are controlled to control the flow of steam. water passing through these two pipes and stabilize the total water vapor flow rate stored in the water vapor accumulator measured by the two flowmeters to a calculated setpoint for storing all excess water vapor from the separator tank water / steam.

Advantageously, the pump is connected to the inlet of the steam generator via a flow meter for measuring the flow of liquid returned from the steam accumulator to the steam generator. water equal to the flow rate of water vapor stored in the accumulator of water vapor and measured by the two flowmeters of the first and second pipes to maintain constant the mass of liquid in the accumulator of water vapor.

Preferably, the second conduit opens into the water vapor accumulator via injection nozzles.

A check valve is arranged in parallel with the controlled valve of the first pipe to ensure the circulation of water vapor from the accumulator of water vapor to the consumer of water vapor during a decline pressure at the outlet of the water / steam separator tank due to a drop in the steam generator load.

A pipe connects the bottom of the steam accumulator to the inlet of the steam generator via a pump and comprises in series a controlled valve and a flowmeter can be opened to regulating a flow of liquid from the accumulator of water vapor to the inlet of the steam generator measured by the flow meter and equal to the flow rate of water vapor measured by the flow meter of the first pipe during the decrease pressure outlet of the water / vapor separator tank so as to maintain a constant mass of liquid in the water vapor accumulator.

According to one embodiment, the thermal energy production system comprises two accumulators of water vapor connected in parallel and whose spaces above their liquid water levels are connected to the first pipe, with the second pipe connected to the vicinity of the bottoms of the two accumulators of water vapor and the pump connected to the bottoms of the two accumulators of water vapor.

According to another embodiment, the thermal energy production system comprises two accumulators of water vapor connected in echelon at the outlet of the water / steam separator tank respectively via two sets of first and second lines. provided with the valves controlled with the pump connected to the bottoms of the two steam accumulators via respectively two controlled valves.

The steam generator is constituted by at least one tube in which circulates water brought to the vapor state by a line of mirrors of a solar installation reflecting solar radiation to the tube.

The thermal energy production system comprises a centralized controller for managing all of the components of the system during the storage and retrieval phases of the thermal energy.

The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the explanatory description which follows with reference to the accompanying drawings given solely by way of example illustrating three Embodiments of the invention and in which: - Figure 1 shows a diagram of a thermal energy production system according to a first embodiment of the invention in non-storage configuration of water vapor in an accumulator water vapor from this system; FIG. 2 represents the thermal energy production system of the first embodiment in a configuration relating to a first phase of storing water vapor in the water vapor accumulator; FIG. 3 represents the thermal energy production system of the first embodiment in a configuration relating to a second phase of storing water vapor in the water vapor accumulator; FIG. 4 represents the thermal energy production system of the first embodiment in a configuration of retrieval of water vapor from the steam accumulator; - Figure 5 shows the thermal energy production system of the first embodiment in a stationary configuration; FIG. 6 represents the thermal energy production system according to a second embodiment of the invention; and - Figure 7 shows the thermal energy production system according to a third embodiment of the invention.

The thermal energy production system, which will be described with reference to Figures 1 to 7, is intended to be applied in an industrial solar plant operating in direct steam generation.

Such a solar installation essentially comprises a solar field consisting of parallel lines of solar modules, each comprising a set of mirrors reflecting solar radiation to a horizontal tube in which circulates a coolant consisting of water brought to the state of vapor in order to recover the energy in thermal form.

The different parallel tubes through which the heat transfer fluid (water) is connected to their inputs by a common pipe of fluid inlet (water) and their outputs by a common outlet pipe of the fluid (water).

The water vapor produced by these tubes can be transmitted to a steam turbine of a turbo-generator set to produce electricity.

However, the thermal energy production system of the invention can also be applied to any other steam generator such as for example a boiler.

Figures 1 to 5 show a first embodiment of the thermal energy production system of the invention.

This system comprises a steam generator 1, whose outlet pipe 2 opens in the vicinity of the bottom wall of a water / vapor separator tank 3 partially filled with liquid water into which leads the pipe 2 .

The portion forming space or sky above the liquid water level of the water / steam separator tank 3 is connected to an outlet pipe 4 for supplying water vapor from the water / steam separator tank. 3 to at least one consumer 5, which can be constituted by a steam turbine of a turboalternator assembly providing electricity.

A flowmeter 6 is disposed in the outlet pipe 4 upstream of the consumer 5 to measure the flow of water vapor supplied to this consumer.

The reference 7 symbolizes a device for automatically measuring the liquid water level in the water / vapor separator tank 3 which may be, for example, of the radar, magnetic or other type and known per se.

A pipe 8 is connected to the bottom wall of the water / steam separator tank 3 opening into the liquid water thereof and is connected to the inlet of the steam generator 1 via a hydraulic pump 9 and a flow meter 10 connected in series.

The thermal energy production system further comprises a water vapor accumulator 11 partially filled with liquid water, whose water level can be measured by an automatic measuring device 12 identical to the measuring device. automatic 7.

A first pipe 13 is connected to the outlet pipe 4 of the water / steam separator tank 3 upstream of the flowmeter 6 and to the water vapor accumulator 11, opening into the part forming a space or sky located at above the level of the liquid water of this accumulator.

The first conduit 13 comprises connected in series a flow meter 14 and a controlled valve 15, whose functions will be described later.

A second pipe 16 is connected to the outlet pipe 4 of the water / steam separator tank 3 upstream of the flow meter 6 and to the water vapor accumulator 11, opening into the liquid water of this accumulator in the vicinity. from the bottom wall of it.

The pipe 16 comprises connected in series a flow meter 17 and a controlled valve 18, whose functions will be described later.

A non-return valve 15a is arranged in parallel with the controlled valve 15 and its function will be described later.

A pipe 19 is connected on the one hand to the bottom wall of the water vapor accumulator 11 by opening into the liquid thereof and on the other hand to the inlet of the hydraulic pump 9 via another hydraulic pump 20 and a flowmeter 21 connected in series, the flowmeter 21 being connected at the output of the hydraulic pump 20.

Another pipe 22 is connected firstly to the bottom wall of the water vapor accumulator 11 by opening into the liquid of this accumulator and secondly to the outlet pipe 8 by the intermediate of a controlled valve 23 and a flow meter 24 connected in series.

A pipe 25 is connected firstly to a source of cold water supply S (feedwater) and secondly to the pipe 8 via a controlled valve 26 and a flowmeter 27 connected in series.

The operation of the thermal energy protection system without storing water vapor will be described with reference to Figure 1.

In this figure, as symbolized in dotted lines, the valves 15, 18, 23 and the hydraulic pump 20 are inactive, so that no water vapor circulates in the first and second lines 13, 16 and that liquid water is not withdrawn by the pump 20 and the pump 9 of the steam accumulator 11 to the steam generator 1 through the lines 19, 22.

When the charge of the steam generator 1 increases, the flow of water vapor output of the generator will increase and the water / steam mixture is separated in the separator tank 3, the water vapor produced at the outlet of this balloon is transmitted by line 4 to the consumer 5.

The liquid water of the water / vapor separator tank 3 is returned to the inlet of the steam generator 1 by the circulation pump 9, which operates at a given flow rate, possibly depending on the charge of the steam generator. water 1.

In addition, the valve 26 is controlled at its open position to return directly to the inlet of the steam generator 1 a flow of food water from the source S controlled by the flow meter 27 and which is regulated according to an algorithm dependent on the vapor flow rate measured by the flow meter 6, the feed water flow rate measured by the flow meter 27, the liquid level of the water / vapor separator tank 3 measured by the device 7 and conditions in the generator of water vapor 1 (temperature, pressure, etc.). This algorithm for calculating the feedwater flow does not depend at all on the storage of water vapor in the water vapor accumulator 11.

The procedure for storing water vapor in the water vapor accumulator 11 will now be described with reference to FIGS. 2 and 3.

The purpose of the steam storage is to use the excess water vapor produced at the output of the steam generator 1 and which corresponds to the situation in which the steam generator 1 produces more water vapor than that consumed by the consumer 5.

The storage will be filled when all the liquid water contained in the water vapor accumulator 11 will be at the maximum temperature.

In addition, the steam produced by the steam generator 1 will be saturated steam, generally at the maximum operating pressure of the consumer 5 constituted by a steam turbine of a set of a turbo-alternator .

FIG. 2 represents the first storage phase of pressurizing the water vapor accumulator 11.

For this purpose, the valve 15 is controlled to open slightly to inject into the sky of the water vapor accumulator 11 an excess of water vapor from the water / steam separator tank 3 allowing the to pressurize this accumulator to a pressure relatively close to that at the outlet of the water / vapor separator tank 3. More precisely, the water vapor injected by the valve 15 arrives in the vapor sky of the steam accumulator. water 11 and will not mix with the liquid water of this accumulator. Part of the water vapor will condense at the walls of the water vapor accumulator 11 to heat them to a saturation temperature and the other part of the vapor will condense on the surface of the liquid water of this accumulator to create a thermocline, which will be all the more stable as the temperature gradient will be high. A final part of the water vapor will be used for the actual pressurization of the vapor sky in the water vapor accumulator 11.

It should be noted that the flow rate of water vapor, measured by the flow meter 14, is regulated via the opening of the valve 15.

The pump 20 makes it possible to return a flow of liquid from the water vapor accumulator 11 to the inlet of the steam generator 1 in order to keep a mass of liquid water substantially constant in the steam accumulator. water 11 during the injection of water vapor into the space or sky of this accumulator.

Thus, the pump 20 returns a flow of liquid water measured by the flow meter 21 and which is equal to the flow rate of water vapor stored in the water vapor accumulator 11 and measured by the flow meter 14, with possibly a correction factor related to the liquid water level of the steam accumulator 11 and measured by the device 12 for maintaining the mass of constant liquid in this accumulator. It should be noted that the regulation of the liquid water level of the accumulator 11 thus begins in the first storage phase, but with liquid water flow rates returned by the pump 20 very low.

The second phase of storage is shown in Figure 3 once the water vapor accumulator 11 is sufficiently pressurized.

At this stage, the so-called admission valve 18 of the second pipe 16 is controlled at its open position, allowing the admission of water vapor to the bottom of the water vapor accumulator 11, for example by means of injection nozzles, not shown, connected to the end of the pipe 16 opening into the water vapor accumulator 11. The water vapor injected by the inlet valve 18 is will fully condense in the water vapor accumulator 11, since it will encounter a water substantially cooler than the saturation temperature. The valve 15, by opening or closing in a controlled manner, can adjust the pressure difference between the water / steam separator tank 3 and the water vapor accumulator 11, which will change the flow of water vapor The valve 15 can thus, for example by means of a control loop of the PID (Proportional-Integral-Derivative) type, stabilize the flow rate of total water vapor stored in the reactor. accumulator 11, measured by the two flowmeters 14, 17, to a set value calculated to store the excess steam assembly from the water / steam separator tank 3. Thus, the high pressure steam and high temperature, arriving in the water vapor accumulator 11 at the bottom of the latter condenses instantly and completely, increasing the temperature of the liquid water contained in this accumulator.

In the variant which has just been described, the inlet valve 18 is of the all-or-nothing type and the flow rate of water vapor therethrough is controlled by the valve 15.

According to another embodiment, the inlet valve 18 may be like the valve 15 a control valve, so that the control of the flow of water vapor injected into the water vapor accumulator 11 through the first and second lines 13, 16 will be shared between the two valves 15, 18.

During this phase, the pump 20 maintains operation identical to the previous phase, in order to maintain a substantially constant liquid water mass in the water vapor accumulator 11.

It should be noted that since the pump 20 will only be in operation in surplus power situations, the other pump 9 will still be in operation when the pump 20 is operating. The water returned to the steam generator 1 will be a mixture of water from the water / steam separator tank 3, water from the steam accumulator 11 and feed water from the source S. In the steam generator 1 in vaporization, the flow of water injected at the outlet of the flowmeter 10 must always be greater than the outgoing steam flow in order to keep the entire steam generator 1 wet in all circumstances. This means that the flow of water from the water / steam separator tank 3 and returned to the steam generator 1 will always be strictly positive.

FIG. 4 represents the procedure for retrieval of the water vapor from the water vapor accumulator 11 during a drop in the charge at the outlet of the water / vapor separator tank 3 and due to a decrease in the power of the steam generator 1 due to the daily decrease in solar power while the consumer 5 constituted in this case by a steam turbine of a turboalternator set required a constant load. This destocking procedure can also be caused in the configuration where the charge of the steam turbine of the turbo-generator (consumer 5) increases in such a way that more water vapor is required by the consumer than that produced by the steam generator 1 .

During this drop in load, the outlet pressure of the water / steam separator tank 3 will decrease, causing the opening of the check valve 15a, so that the high temperature liquid contained in the steam accumulator water 11 will vaporize at the outlet of this accumulator, which water vapor will flow through the first pipe 13 to supply the consumer 5.

In addition, the valve 23 is controlled at its open position to regulate a flow of liquid water from the water vapor accumulator 11 to the inlet of the steam generator 1, measured by the flowmeter 24 and equal to the flow rate of water vapor measured by the flowmeter 14 of the first pipe 13 so as to maintain a substantially constant mass of water in the accumulator 11, water vapor flow possibly corrected by the level measured by the device 12.

It should also be noted that during this phase of destocking, the valve 26 is controlled at its open position and the flow of feedwater injected via the valve 26 and measured by the flowmeter 24, will be greater than the flow rate. water vapor produced by the steam generator 1, since calibrated on the total flow of water vapor measured by the flow meter 6 upstream of the consumer 5.

FIG. 5 represents the system for producing thermal energy at a standstill and the totality of the flow of the food water coming from the source S is returned to the water vapor accumulator 11 via the valves 23. , 26 ordered to their fully open position.

The destocking of the steam will be carried out until the minimum pressure of destocking is reached, which pressure will depend on the recovery process of this steam.

It should be noted that a centralized controller, not shown, will manage all the above described components of the thermal energy production system both during the storage phase and during the destocking phase.

FIG. 6 represents an embodiment according to which the thermal energy production system comprises two water vapor accumulators 11 connected in step, each of these accumulators being associated with the same components as those previously described in connection with FIG. the water vapor accumulator 11 with reference to FIGS. 1 to 5, so that, in particular during the storage phase, one of the two accumulators will be charged after the other accumulator 11 is filled with water vapor . It is therefore unnecessary to describe again in detail the different storage and retrieval operating phases of this embodiment and it is sufficient to refer to the storage and retrieval phases previously described. The only difference in this embodiment is that it is necessary to add two controlled valves located respectively in two pipes 31 connected on the one hand to the bottoms of the two accumulators 11 and on the other hand to the inlet of the pump 20 to allow the good operation in series of the two accumulators 11.

FIG. 7 represents a third embodiment of the thermal energy production system of the invention according to which two water vapor accumulators 11 are connected in parallel, in which case they will be simultaneously charged with water vapor. According to this embodiment, the first pipe 13 is connected by two pipes 13a, 13b respectively in the skies of the two steam accumulators 11 located above their respective water levels and the second pipe 16 is connected to two pipes 16a. , 16b opening respectively in the vicinity of the bottom walls of the two accumulators 11 partially filled with water. For operation particularly in the storage and retrieval phases, it suffices to refer to the embodiment described with reference to FIGS. 1 to 5 and whose components are the same as those of the third embodiment.

The thermal energy production system of the embodiments as shown in FIGS. 6 and 7 is in the storage configuration corresponding to that of FIG. 3.

The above-described thermal energy production system described in its various embodiments makes it possible in a simple manner to store thermal energy from a steam generator, such as a boiler or horizontal tubes of a solar installation in which circulates a coolant (water) to be heated by the solar radiation. This system allows the storage of water vapor without mass transfer from a cold tank to a hot tank, thus avoiding the oversizing of energy recovery equipment or the installation of additional equipment dedicated to the storage function. .

Claims (11)

1. A thermal energy production system, characterized in that it comprises a generator of high pressure and high temperature water vapor (1); a water / steam separator tank (3) connected at the outlet of the steam generator (1); a water vapor consumer (5) connected at the outlet of the water / steam separator tank (3); at least one water vapor accumulator (11) containing liquid water and connected to the outlet of the water / vapor separator tank (3) upstream of the inlet of the steam consumer (5) by the intermediate of two parallel pipes respectively a first pipe (13) opening into the water vapor accumulator (11) in the space above the level of the liquid water and comprising a controlled valve (15) which can be open to inject into the space of the water vapor accumulator (11) an excess of water vapor from the water / steam separator tank (3) for pressurizing the water vapor accumulator (11) to a pressure relatively close to that of the water / vapor separator drum (3) and a second pipe (16) opening into the liquid water in the vicinity of the bottom of the steam accumulator (11) and having a controlled valve (18) which can be opened when the steam accumulator at (11) is at the pressure close to that of the water / vapor separator drum (3) for injecting an excess of steam from this balloon into the liquid water of the steam accumulator (11) with increasing temperature of the liquid water; and a pump (20) connected to the bottom of the steam accumulator (11) for returning a flow of liquid water from the steam accumulator (11) to the inlet of the steam generator of water (1) in order to maintain a constant mass of liquid water in the water vapor accumulator (11) during the injection of steam into the space and the bottom of the steam accumulator (11) through the first and second lines (13,16). 2. Thermal energy production system according to claim 1, characterized in that the first and second pipes (13,16) respectively comprise two flow meters (14,17) for measuring the flow of water vapor in these two pipes and the valve (15) in the first pipe (13) is controlled to control the flow of water vapor passing mainly through the valve (18) of the second pipe (16) and stabilize the flow of water vapor total stored in the water vapor accumulator (11) measured by the two flowmeters (14,17) to a calculated setpoint for storing all of the excess water vapor from the water / vapor separator tank ( 3). 3. Thermal energy production system according to claim 1, characterized in that the first and second pipes (13,16) respectively comprise two flow meters 14,17) for measuring the flow of water vapor in these two pipes. and the two valves (15, 18) of the first and second lines (13, 16) are controlled to control the flow of water vapor passing through these two lines and to stabilize the flow rate of total water vapor stored in the accumulator water vapor (11) measured by the two flowmeters (14,17) at a calculated setpoint for storing all surplus water vapor from the water / steam separator tank (3). Thermal energy production system according to claim 2 or 3, characterized in that the pump (20) is connected to the inlet of the steam generator (1) via a flow meter ( 21) for measuring the flow of liquid water returned from the steam accumulator (11) to the steam generator (1) equal to the flow rate of water vapor stored in the steam accumulator. water (11) and measured by the two flowmeters (14,17) of the first and second lines (13,16) to maintain constant the mass of liquid water in the steam accumulator (11). 5. Thermal energy production system according to one of claims 1 to 4, characterized in that the second pipe (16) opens into the water vapor accumulator (11) via nozzles. injection. 6. Thermal energy production system according to one of claims 1 to 5, characterized in that a non-return valve (15a) is arranged in parallel with the controlled valve (15) of the first pipe (15) to ensure the circulation of water vapor from the water vapor accumulator (11) to the water vapor consumer (5) during a pressure drop at the outlet of the water / vapor separator tank (3) due to at a load drop of the steam generator (1). 7. Thermal energy production system according to claim 6, characterized in that a pipe (22) connects the bottom of the steam accumulator (11) to the inlet of the steam generator. (1) via a pump (9) and comprises in series a controlled valve (23) and a flowmeter (24) which can be opened to regulate a flow of liquid water from the steam accumulator (11) to the inlet of the steam generator (1) measured by the flowmeter (24) and equal to the flow rate of water vapor measured by the flowmeter (14) of the first pipe (13) during the pressure drop at the outlet of the water / vapor separator tank (3) so as to maintain a constant mass of liquid water in the steam accumulator (11). 8. Thermal energy production system according to one of claims 1 to 7, characterized in that it comprises two water vapor accumulators (11) connected in parallel and whose spaces above their water levels. liquid water are connected to the first pipe (13), with the second pipe (16) connected to the vicinity of the bottoms of the two steam accumulators (11) and the pump (20) connected to the bottoms of the two steam accumulators of water. (11) 9. Thermal energy production system according to one of claims 1 to 7, characterized in that it comprises two steam accumulators (11) connected in echelon at the outlet of the water / steam separator tank (3). via respectively two sets of first and second pipes (13,16) provided with the controlled valves (15,18) with the pump (20) connected to the bottoms of the two water vapor accumulators (11) by the intermediate respectively of two controlled valves (30). 10. Thermal energy production system according to one of claims 1 to 9, characterized in that the steam generator (1) is constituted by at least one tube in which circulates water brought to the water. state of vapor by a line of mirrors of a solar installation reflecting solar radiation to the tube. 11. Thermal energy production system according to one of claims 1 to 10, characterized in that it comprises a centralized controller for managing all of the components (15, 18, 23, 26, 30) of the system during the storage and retrieval phases of thermal energy.