FR2947618A1 - SAFETY DEVICE FOR A HEATING PLANT, HEATING PLANT EQUIPPED WITH SUCH A SAFETY DEVICE, AND METHOD FOR SECURING A HEATING PLANT - Google Patents

Abstract

The invention relates to a safety device for a heating installation comprising: a boiler (3), a tank (5) for receiving condensates equipped with a sensor (6) of a safety level; a primary circuit (1) for heating the dwelling; a secondary circuit (2) for heating the sanitary water; a filling loop of the primary circuit (1) by the secondary circuit (2), characterized in that it comprises a device (8) for controlling a safety valve adapted to be connected to said sensor (6) of said level of security and adapted to control the closing of said safety valve (7) as soon as said sensor (6) detects that said security level is reached in said receiving tray (5). The invention also relates to an installation equipped with such a safety device and a method for securing a heating installation.

Description

Safety device for a heating installation, heating installation equipped with such a safety device, and method for securing a heating installation 1. Technical field of the invention The invention relates to the securing of heating installations, in particular the installations comprising boilers. The invention also relates to such installations and safety devices for such heating installations. The invention also relates to methods for securing heating installations. 2. Technological Background Throughout the text, the term heating plant designates a set of devices set up, arranged and associated with each other, and for heating a home. The term dwelling refers to any building, for private or public use, intended to shelter people, animals, machines or objects. A heating installation for a dwelling comprises, in a known manner: a boiler, a primary circuit for heat exchange by heat transfer fluid, called primary fluid, arranged between the boiler and at least one heating device of the dwelling such as a radiator, a secondary circuit for heating the sanitary water, a calibrated safety valve arranged on the primary circuit and adapted to evacuate overpressures of primary fluid from the primary circuit by an evacuation channel, a filling loop connecting the secondary circuit and the primary circuit and comprising a valve for allowing or not the passage of secondary fluid from the secondary circuit to the primary circuit.

The filling loop has the function of allowing the filling of the primary heating circuit or readjusting the quantity of primary fluid in this circuit, in case of leakage of the primary circuit. One of the disadvantages of a known installation appears when a technical problem occurs on the installation.

For example, in the event of leakage from the filling valve, or a failure to close this filling valve, or even the accidental opening of this filling valve by a child, the primary and secondary circuits may inadvertently communicate with each other. with each other. In particular, in such a situation, the secondary circuit of domestic water leaks into the primary circuit since the pressure of the secondary circuit is greater than the pressure of the primary circuit. The primary circuit then sees arrive a large amount of cold water it heats through the boiler, which causes increased operation of the boiler, thus leading in particular to excessive consumption of energy.

Another technical problem that may arise concerns the safety valve calibrated at a predetermined pressure whose function is to evacuate the primary fluid in the event of a rise in pressure of the primary circuit. This rise in pressure may for example occur during a failure to close the filling valve. Such a rise in pressure leads to the deformation of the compressible parts of the primary circuit (expansion vessel, air pockets) and to the inlet of an additional volume of fluid in the primary circuit. When the pressure reaches the predetermined value of the safety valve, the additional volume of fluid is discharged through the evacuation channel of the safety valve to the waste water pipes. This can lead to more or less water flow without anyone realizing it and thus wasting sanitary water. In addition, the phenomenon previously described in case of leakage of the filling valve also occurs, that is to say that the boiler will operate unnecessarily to heat the cold water arriving from the secondary circuit. Some heating systems further comprise a heat exchanger arranged jointly on the primary circuit and the secondary circuit and adapted to ensure heat exchange between the primary fluid of the primary circuit and the sanitary water of the secondary circuit. These heating systems are commonly referred to as mixed heating installations. Such a mixed heating system allows on the one hand to ensure the heating of the house through the primary heating circuit, and on the other hand to ensure the heating of the sanitary water through the secondary circuit. Indeed, the boiler heats the primary fluid that is conveyed by the primary circuit to the heating devices of the house. In addition, the heat exchanger makes it possible to ensure heat exchange between the primary fluid heated by the boiler circulating in the primary circuit and the sanitary water of the secondary circuit. The devices for dispensing heated sanitary water, such as showers, are arranged downstream of the heat exchanger. Such an installation may encounter a problem of oxidation of the heat exchanger which may lead to its rupture. Such a rupture leads to the fluidic communication of the primary and secondary circuits. The previously described phenomenon then occurs: the secondary circuit of domestic water leaks into the primary circuit since the pressure of the secondary circuit is greater than the pressure of the primary circuit; the primary circuit then sees arrive a large amount of cold water that it heats through the boiler, which causes increased operation of the boiler, thus leading in particular to excessive consumption of energy. For all the problems described, the technique commonly used today to overcome these failures is to completely stop the installation. An operator must then go on site, change or repair the defective item. As long as this operator did not go on site to repair the installation, neither circuit can work, ie not only the domestic water is no longer heated, but also the heating circuit is totally stopped, which can be problematic depending on the season, especially for cold-sensitive populations - elderly, sick, fragile, etc. 3. Objectives of the invention The invention aims in particular to provide an installation overcoming the disadvantages of the prior art. In particular, the invention aims at proposing an installation, which in at least one embodiment limits water losses in the event of a technical problem occurring on the installation such as a failure to close the system. a valve of a filling loop, a leakage of a safety valve or a rupture of a heat exchanger if necessary, or an equivalent failure. The invention also aims at proposing an installation, which in at least one embodiment limits the energy expenditure in the event of a technical problem occurring on the installation such as a failure to close a valve of a filling loop, leakage from a safety valve or rupture of a heat exchanger if applicable, or equivalent failure. The invention also aims to propose an installation, which in at least one embodiment, allows the continued operation of the primary heating circuit, including in the event of a major malfunction of the installation. The invention also aims at providing a method for securing heating installations so that they overcome the disadvantages of heating installations of the prior art. The invention also aims at providing a safety device for a heating installation. Another object of the invention is to provide such a safety device, which is simple and inexpensive to manufacture and to implement, compared to known techniques. 4. DISCLOSURE OF THE INVENTION To this end, the invention relates to a safety device for a heating installation comprising: a boiler, a primary circuit for heat exchange by heat transfer fluid, called primary fluid, arranged between the boiler and at least one heating device, a secondary circuit for heating a secondary fluid comprising a secondary fluid source, a calibrated safety valve, arranged on the primary circuit and adapted to discharge the primary fluid overpressures of the primary circuit by a discharge channel, a filling loop connecting the secondary circuit and the primary circuit and comprising a valve, called filling valve, to allow or not the passage of secondary fluid from the secondary circuit to said primary circuit.

A safety device according to the invention is characterized in that it comprises a device for controlling a safety valve mounted on the secondary circuit and which can be placed at least in a first position, called an open position, in which said fluid secondary can flow freely in the secondary circuit and a second position, said closed position, wherein said secondary circuit downstream of the safety valve is no longer supplied with secondary fluid. The safety device according to the invention is also characterized in that the control device of the safety valve is adapted to be connected to a sensor of detection of a predetermined level of fluid, said level of safety, in a tray of receiving fluid supplied by said evacuation channel and for controlling the closing of said safety valve as soon as said sensor detects that said security level is reached. A safety device according to the invention therefore makes it possible, once set up on a heating installation, to cut the secondary circuit for heating the secondary fluid, which is advantageously the circuit for heating the sanitary water as soon as the safety sensor detects that the fluid level in a receiving tank connected to the evacuation channel of the safety valve is reached. Therefore, any significant leakage of the safety valve is detected by the sensor mounted on a receiving tank fed by the evacuation channel of the safety valve. The control device, connected to this sensor, can then control the closing of the safety valve, which allows to cut off the power of the secondary circuit, and thus to limit water wastage. Likewise, in the event of a fault in closing the filling loop valve, the overpressure of the primary circuit resulting from the influx of fluid from the secondary circuit is evacuated by the safety valve, which causes an increase in the fluid level. in the receiving tank fed by the evacuation channel of this safety valve. As soon as the safety level is reached, the control device closes the safety valve, which avoids any risk of further waste while waiting for the maintenance of the installation.

Advantageously, a safety device according to the invention comprises means for holding said safety valve in said closed position, adapted to maintain said safety valve in said closed position as soon as said safety valve occupies said closed position. The means for holding the safety valve in the closed position is an assurance that the safety valve remains in the closed position as soon as the sensor detects that the safety level has been reached. Advantageously, a safety device according to the invention comprises means for opening said safety valve adapted to cancel the effect of said holding means of said safety valve and to manually move said safety valve from said closed position. at said open position. A safety device according to this variant of the invention allows re-opening of the safety valve only by means of manual means which constrain the means for holding the valve in the closed position. Thus, only a manual action of an operator on the safety valve makes it possible to return it to the open position. According to a variant of the invention, the holding means comprise a bistable microswitch (better known by its name in English bistable microswitch) and the opening means of the safety valve 30 comprise a button connected to the bistable microswitch so that pressing the button switches the microswitch from one stable state to another.

A bistable microswitch has two possible stable states and can change state under the action of an input power variable, in this case the detection of the security level, and maintain this state even when the action of the supply quantity is stopped. Only another appropriate action can change the state. According to this variant of the invention, the initiating action of the first change of state is the detection of the security level and the second change of state action is the manual pressure on a button connected to the microswitch. Thus, the button cancels the effect of the holding means of said safety valve and allows manual movement of the safety valve from the closed position to the open position by an operator. According to another variant of the invention, the holding means comprise a bistable electrical relay associated with a junction box and the opening means comprise a button for switching the relay from one state to another.

A safety valve controlled by a control device of a safety device according to the invention can be of any type. In particular, the safety valve may be a valve controlled by pneumatic means or by hydraulic means or by electrical means or by a combination of these means.

Advantageously and according to the invention, said safety valve is a solenoid valve. Advantageously and according to the invention, the safety valve is a monostable solenoid valve controlled by a bi-stable electrical relay. According to a variant of the invention, the safety valve is a bistable solenoid valve. According to this variant, the holding means of the safety valve in the closed position and the manual opening means of the safety valve are directly integrated in the valve. The opening means comprise, for example, a mechanical cam which makes it possible to manually switch the safety valve from one position to another. A safety device according to the invention may also be advantageously mounted on a mixed heating installation comprising a heat exchanger arranged jointly on said primary circuit and said secondary circuit and adapted to ensure heat exchange between the primary fluid of the primary circuit and the sanitary water of the secondary circuit.

Therefore, a safety device according to the invention makes it possible, once set up on such a mixed heating installation, to cut off the secondary heating circuit of the secondary fluid, which is advantageously the circuit for heating the sanitary water as soon as the safety sensor detects that the fluid level in the receiving tray reaches the safety level.

Therefore, in case of rupture of the heat exchanger of the installation, the secondary circuit is cut (following the detection of the safety level) so that the heat exchanger is no longer supplied with domestic water. Thus, as soon as the safety sensor detects that the safety level is reached, the cold sanitary water is no longer discharged into the primary circuit, eliminating the need to maintain an increased operation of the boiler to heat this water. It is therefore possible to maintain normal operation of the primary heating circuit of the house. Normal operation of the primary circuit means that the boiler from time to time enroute to warm the primary fluid of the heating circuit when it has a temperature below a predetermined temperature. A safety device according to the invention therefore allows continuity of operation of the heating circuit of the dwelling despite the occurrence of a failure of a device of the installation. This failure may be a rupture of the heat exchanger. This failure can also be a leak on a safety valve present on the primary circuit. This failure can also result from a leak on a filling valve present on a filling loop connecting the primary circuit and the secondary circuit. This failure may also be due to a forgetfulness of closure of the filling valve by a user, or improper handling of this filling valve. A safety device according to the invention can also be advantageously mounted on a heating installation comprising a condensing boiler and a condensate lifting device. A condensing boiler is used to heat the primary fluid circulating in the boiler by the water vapor present in the combustion gases.

This water vapor condenses on cooling and forms droplets of water designated throughout the text by condensates. To evacuate these condensates to sewage pipes, it is known either to use the gravity flow or to equip the boiler with a condensate lift device. This condensate draining device includes a condensate pump and a condensate tray. It is common to equip the condensate collection tray with a sensor for detecting predetermined levels of condensate in the receiving pan, including a minimum level and a maximum level, to control the lifting pump. An additional level, referred to as the security level, and above the maximum level, is generally provided for detecting an abnormality, such as a pump failure, and generating an alarm. A safety device according to the invention can thus, when it is mounted on a heating installation equipped with a condensing boiler equipped with a condensate removal device, use the condensate receiving tray as the receiving tray of the fluid from the evacuation pipe and use one of the sensors of this condensate lifting device as a detection sensor of the security level. A safety device according to the invention is therefore particularly suitable for heating installations comprising condensing boilers. The invention also relates to a heating installation equipped with a safety device according to the invention. To do this, the invention relates to a heating installation comprising: a boiler, a primary heat exchange circuit by heat transfer fluid, said primary fluid, arranged between the boiler and at least one heating device, a secondary heating circuit, a secondary fluid comprising a source of secondary fluid, a filling loop connecting the secondary circuit and the primary circuit and comprising a valve, called filling valve, to allow or not the passage of secondary fluid from the secondary circuit to the circuit primary, a calibrated safety valve, arranged on the primary circuit and adapted to evacuate overpressures of primary fluid from the primary circuit through an evacuation channel.

An installation according to the invention is characterized in that it comprises a safety device according to the invention. According to an advantageous variant of the invention, the boiler is a condensing boiler comprising a condensate removal device comprising a condensate receiving pan equipped with a sensor of at least one predetermined level of condensates, said level of safety, said receiving pan being further supplied by said evacuation channel. Advantageously, an installation according to the invention comprises a heat exchanger arranged jointly on the primary circuit and the secondary circuit and adapted to ensure heat exchange between the primary fluid of the primary circuit and the secondary fluid of the secondary circuit. The security sensor can be of all types. In particular, it may comprise a dry contact sensor, a capacitive sensor, a hall effect sensor, etc. According to an advantageous variant of the invention, the safety sensor is a dry contact sensor. Such a sensor can be mounted without difficulty on the condensate receiving tray, presents no particular danger, especially in the vicinity of a condensing boiler and can provide a robust control signal to the safety valve.

The primary and secondary fluids can be of all types. That being so, the invention is particularly intended for the joint heating of a dwelling and sanitary water. Also, according to an advantageous variant of the invention, the primary fluid and the secondary fluid are water. The invention also relates to a method of securing a heating installation comprising: a boiler, a primary circuit for heat exchange by heat transfer fluid, called primary fluid, arranged between the boiler and at least one heating device, 10 a secondary circuit for heating a secondary fluid comprising a source of secondary fluid, a filling loop connecting the secondary circuit and the primary circuit and comprising a valve, called a filling valve, permitting or not allowing the passage of secondary fluid from the 15 secondary circuit to the primary circuit, a calibrated safety valve, arranged on the primary circuit and adapted to evacuate the primary system primary fluid overpressures by a discharge channel. A method according to the invention is characterized in that it comprises the steps of: ù mounting a safety valve on the secondary circuit adapted to be placed at least in a first position, said open position, wherein said secondary fluid can flow freely in the secondary circuit and a second position, said closed position, in which said secondary circuit downstream of the safety valve is no longer supplied with secondary fluid, connect a control device of said safety valve a sensor of detection of a predetermined level of fluid, said level of security, in a fluid receiving tank fed by said discharge channel, so as to be able to control the closing of said safety valve as soon as said sensor detects that said security level is reached. A method of securing a heating installation allows an upgrade of an existing installation to give it the functionality of a heating installation according to the invention. Such a method of securing consists of equipping an existing heating installation with a safety device according to the invention. A method according to the invention thus makes it possible to improve the existing heating installations by providing them with functionalities making it possible, in the event of damage, to maintain the operation of the primary heating circuit, and by limiting the energy losses, the losses of water and mounting difficulties. Advantageously, a securing method according to the invention further comprises the step of equipping the boiler with a condensate lift pump comprising a condensate receiving pan provided with a sensor for detecting a predetermined level of condensates. in said receiving tray, this sensor being connected to said control unit. In particular, according to this method, it is possible not only to equip installations comprising condensing boilers, but also to equip conventional boilers with a condensate removal device, so as to use the tank of this lifting device of condensate as a fluid receiving tank from the evacuation channel of the safety valve. The invention also relates to a safety device for a heating installation of a dwelling, an installation equipped with a safety device according to the invention, and a method of securing a heating installation characterized in combination by all or part of the characteristics mentioned above or below. 5. List of Figures Other objects, features and advantages of the invention will appear on reading the following description given solely by way of non-limiting example and which refers to the appended figures, in which: FIG. 1 is a diagrammatic view partial of a heating installation according to an embodiment of the invention equipped with a safety device according to one embodiment of the invention, Figure 2 is a partial schematic view of a heating system according to a method of embodiment of the invention equipped with a safety device according to one embodiment of the invention, FIG. 3 is a schematic view of a heating installation according to an embodiment equipped with a safety device according to a embodiment of the invention and mounted in a dwelling. 6. DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION A partial view of a heating installation according to one embodiment of the invention is shown in FIG. 1. This installation comprises a primary circuit 1 for heat exchanges. by heat transfer fluid, said primary fluid, arranged between a condensing boiler 3 and at least one heating device (not shown in Figure 1 for the sake of clarity).

The installation also comprises a secondary circuit 2 for heating a secondary fluid comprising a source of secondary fluid (not shown in FIG. 1 for the sake of clarity). The installation also comprises a heat exchanger 4 arranged jointly on the primary circuit 1 and the secondary circuit 2 so as to ensure heat exchange between the heated primary fluid of the primary circuit 1 and the secondary fluid of the secondary circuit 2. According to the embodiment of the figures, the primary fluid and the secondary fluid are running water. The condensing boiler 3 of the primary circuit comprises a condensate recovery device comprising a condensate receiving tray 5 equipped with a sensor 6 of at least one predetermined level of condensates, said level of safety. An installation according to the embodiment of Figure 1 further comprises a safety device according to one embodiment of the invention.

According to the embodiment of Figure 1, the safety device comprises a safety valve 7 mounted on the secondary circuit 2 between the domestic water source (not shown in the figure) and the heat exchanger 4. According to another variant of the invention, the safety device does not comprise a specific safety valve, but drives via the control device a pre-existing safety valve on the secondary circuit 2. This safety valve 7 is for example a solenoid valve. This safety valve 7 is adapted to be placed at least in a first position, called the open position, in which the sanitary water of the secondary circuit 2 can flow freely in the secondary circuit 2 and a second position, called the closed position, in which the secondary circuit 2 downstream of the safety valve 7 is no longer supplied with sanitary water. The arrows on the secondary circuit 2 of FIG. 1 represent the direction of normal water circulation in the circuit, the sanitary water source being upstream of the circuit and the hot water distribution devices, such as showers, being downstream of the heat exchanger 4. The safety device also comprises a device 8 for controlling the safety valve 7 connected to the sensor 6 of the security level. This control device is adapted to control the closing of the safety valve 7 as soon as the sensor 6 detects that the security level is reached. In FIG. 1, the control line between the control device 8 and the safety valve 7 is diagrammatically represented by the reference 10. The transmission line between the sensor 6 and the control device 8 is diagrammatically represented by the reference 11 These control and transmission lines may according to one embodiment of the invention be wire lines. According to another embodiment, these links may be wireless radio links of the Bluetooth, Wifi or equivalent type. The control device 8 is for example an electronic box adapted to receive a signal from the sensor 6 and relay a closing command of the safety valve 7. According to a variant of the invention, the control device 8 and the sensor 6 are integrated in the same housing. According to a variant of the invention, the safety valve 7 is a bistable solenoid valve adapted to remain in the closed state upon receipt of the command from the control device 8. This safety valve 7 then comprises a mechanical cam mounted on the safety valve 7 and adapted to be manipulated by an operator to allow manual release of the safety valve, and thus switch the valve from the closed position to the open position . According to another variant of the invention, the safety device comprises means for holding the safety valve 7 in the closed position, adapted to maintain the valve in the closed position as soon as the valve occupies said closed position. Such means are, for example, bistable electrical relays or bistable microswitches. According to this variant, the device then preferably comprises means for opening the safety valve adapted to cancel the effect of the holding means of the safety valve and to manually move the safety valve 7 from the closed position to the open position.

In Figure 3, an installation according to one embodiment of the invention is shown arranged in a dwelling. This installation comprises a primary circuit 1 comprising a boiler 3 and radiators 12, 13 distributed in the dwelling 14. The boiler 3 and the radiators are connected to each other via conduits for the circulation of water. In addition, the installation comprises a secondary circuit 2 arranged between a source 15 of domestic water and heated water distribution devices such as showers 16, 17 distributed in the dwelling 14. The source 15 of water and showers 16, 17 are connected to each other through pipes for the circulation of water. An installation according to the invention also comprises a heat exchanger 4 arranged on both the primary circuit 1 and the secondary circuit 2. This heat exchanger 4 is for example a plate heat exchanger. Such a plate heat exchanger may consist of superimposed plates of aluminum, stainless steel or composite materials so as to constitute two fluid zones separating the hot flow from the water of the primary circuit and the cold flow of the water of the secondary circuit. Figure 2 shows in more detail the heating system of Figure 3, and shows that the primary circuit comprises according to the embodiment of the figures a safety valve 18. This safety valve is a calibrated valve adapted to evacuate the water overpressure of the primary circuit 1 in case of pressure increase of the primary circuit 1. According to the embodiment of the figures, the safety valve 18 is calibrated between 3 and 6 bars and the primary circuit 1 has in normal operation a pressure of between 1.5 bars and 2.5 bars. In addition, the secondary circuit 2 has a pressure of between 3 bars and 12 bars. Thus, in the event of leakage of the secondary circuit 2 of running water to the primary circuit 1, leading to a rise in pressure of the primary circuit 1, the calibrated safety valve 18 makes it possible to evacuate the water as soon as the pressure reaches its tare value. An installation also comprises, according to the embodiment of the figures, a filling loop 19 connecting the primary circuit 1 and the secondary circuit 2 and comprising a controlled valve 20 making it possible to allow or not the passage of water from the secondary circuit 2 to the primary circuit 1. This filling loop 19 makes it possible to feed the primary circuit 1 with water when the pressure in the primary circuit 1 is too low for optimum operation of the primary heating circuit 1. This pressure drop may result for example from a leak of the radiators 12, 13. In this case, it is necessary to compensate for these leaks by refueling the primary heating circuit 1 from time to time. A leakage of the valve 20 of the filling loop 19 or a closing fault of this filling valve 20 causes the succession of the following phenomena: spontaneous supply of the primary circuit 1 in cold water from the secondary circuit 2; increased operation of the boiler 3 to heat this cold water; accumulation of condensates in the receiving tank 5; detection of the high security level by the sensor 6; control of the closing of the safety valve 7; closing the safety valve 7; maintaining the closure of the safety valve 7 until a manual resetting has been performed by an operator. As previously indicated, in such a situation, the primary heating circuit 1 can continue to operate despite the failure of the installation. The sensor 6 for detecting the security level may be a sensor dedicated to the security device according to the invention and mounted on the receiving tray for this purpose. That is to say, according to this embodiment, the sensor is specially mounted on the receiving tray to be able to detect the level of security and transmit this detection to the control device 8. According to another embodiment of the invention, the sensor 6 may be a pre-existing sensor integrated in a condensate lifting device. In particular, most condensate lifting devices comprise three sensors: a sensor for detecting a minimum level of condensate in the receiving tray; a sensor for detecting a maximum allowed level of condensate in the receiving pan, this level being higher than the minimum level; and a sensor for detecting a security level.

A method of securing a heating installation according to an embodiment according to the invention may then comprise a step of connecting this pre-existing detection sensor of a safety level to a control unit of the safety valve 7. . According to another variant, the security method comprises a prior step of mounting a dedicated sensor independent of the pre-existing sensors on the condensate receiving tray of the condensate lift device. According to the embodiment of FIG. 2, the primary heating circuit 1 of the installation further comprises a circulating pump 21 ensuring the circulation of the primary fluid in the primary heating circuit 1.

The installation also comprises, according to this embodiment, a manometer 22 for measuring the pressure of the primary fluid in the primary circuit 1. The other devices of a heating installation are well known to those skilled in the art and are not described here in detail.

In particular, the condensate lift device comprises a condensate pump which can be a piston pump, a centrifugal pump, a peristaltic pump, a diaphragm pump, or any equivalent pump. According to a variant of the invention, the pump is a single-block pump which directly carries the detection sensor of the security level.

According to one embodiment of the invention, the installation further comprises a pipe 23 connecting the safety valve 18 arranged on the primary circuit 1 to the receiving tank 5. Such a connection line is prohibited in England because of the risk of overflow of the safety tank in the event of failure of the safety valve 18. These risks disappear with a safety device according to the invention. In particular, once set up on a heating installation, the safety device cuts the secondary circuit 2 as soon as the security level is reached and maintains this closing of the valve, which eliminates all flood risks in particular. The invention is not limited to the embodiments described.

In particular, the primary and secondary circuits may comprise other devices without calling into question the safety principle introduced by a safety device according to the invention.

Claims (13)

REVENDICATIONS1. Safety device for a heating installation comprising: - a boiler (3), - a primary heat exchange circuit (1) by heat transfer fluid, called primary fluid, arranged between the boiler (3) and at least one device (12). 13) of heating, - a secondary circuit (2) for heating a secondary fluid comprising a secondary fluid source (15), - a calibrated safety valve (18), arranged on the primary circuit and adapted to evacuate primary fluid overpressures of the primary circuit (1) by an evacuation channel (23), - a filling loop (19) connecting the secondary circuit (2) and the primary circuit (1) and comprising a valve, called a valve ( 20) for permitting or not the passage of secondary fluid from the secondary circuit (2) to the primary circuit (1). characterized in that it comprises a device (8) for controlling a safety valve mounted on the secondary circuit (2) and which can be placed at least in a first position, called the open position, in which said secondary fluid can be free flow in the secondary circuit (2) and a second position, said closed position, in which said secondary circuit (2) downstream of the safety valve (7) is no longer supplied with secondary fluid, said device (8) ) being adapted to be connected to a sensor (6) for detecting a predetermined level of fluid, said safety level, in a fluid receiving tray fed by said evacuation channel and to control the closing of said safety valve (7) as soon as said sensor (6) detects that said security level is reached. 2. Safety device according to claim 1, characterized in that it comprises means for holding said safety valve (7) in said closed position, adapted to maintain said safety valve (7) in said closed position as soon as said safety valve (7) occupies said closed position. 3. Safety device according to claim 2, characterized in that it comprises means for opening said safety valve (7) adapted to cancel the effect of said holding means of said safety valve (7) and allow manually moving said safety valve (7) from said closed position to said open position. 4. Safety device according to one of claims 1 to 3, characterized in that said safety valve (7) is a solenoid valve. 5. Safety device according to one of claims 1 to 4, characterized in that said safety valve (7) is a solenoid valve monostable driven by a bi-stable electrical relay. 6. Safety device according to one of claims 1 to 4, characterized in that said safety valve (7) is a bi-stable solenoid valve. 7. Heating installation comprising: - a boiler (3), - a primary heat exchange circuit (1) by heat transfer fluid, called primary fluid, arranged between the boiler (3) and at least one device (12; 13). a secondary circuit (2) for heating a secondary fluid comprising a secondary fluid source (15), - a filling loop (19) connecting the secondary circuit (2) and the primary circuit (1) and comprising a valve (20) controlled to allow or not the passage of secondary fluid from the secondary circuit (2) to the primary circuit (1), - a calibrated safety valve (18) arranged on the primary circuit and adapted for discharging primary fluid overpressures of the primary circuit (1) via a discharge channel (23), characterized in that it comprises a safety device (6, 8, 7) according to one of claims 1 to 6. 8. Installation according to claim 7, characterized in that said boiler is a condensing boiler comprising a condensate lifting device comprising a tank (5) for receiving condensate equipped with a sensor (6) of at least one level predetermined condensate, said security level, said receiving tank (5) being further supplied by said channel (23) of discharge. 9. Heating system according to one of claims 7 or 8, characterized in that it comprises a heat exchanger (4) arranged jointly on said primary circuit (1) and said secondary circuit (2) and adapted to ensure exchanges between said primary fluid of the primary circuit (1) and said secondary fluid of the secondary circuit (2), 10. Installation according to one of claims 7 to 9, characterized in that said sensor (6) security is a dry contact sensor. 11. Installation according to one of claims 7 to 10, characterized in that said primary fluid and said secondary fluid are water. 12. A method for securing a heating installation comprising: - a boiler (3), - a primary heat exchange circuit (1) by heat transfer fluid, said primary fluid, arranged between the boiler (3) and at least one device (12; 13) for heating, - a secondary circuit (2) for heating a secondary fluid comprising a secondary fluid source (15), - a filling loop (19) connecting the secondary circuit (2) and the circuit (1). primary and comprising a valve (20) to allow or not the passage of secondary fluid from the secondary circuit (2) to the primary circuit (1), - a calibrated safety valve (18) arranged on the primary circuit and 25 adapted to discharge primary fluid overpressures of the primary circuit (1) through a discharge channel (23), characterized in that it comprises the steps of: - mounting a safety valve (7) on the circuit (2) ) secondary adapted to be placed at least in a first position, said open position, wherein said secondary fluid can flow freely in the secondary circuit (2) and a second position, said closed position, wherein said circuit (2 ) secondary downstream of the valve (7) of safety is no longer supplied with secondary fluid, - connect a device (8) for controlling said safety valve (7) to a sensor (6) for detecting a predetermined level of fluid, said safety level, in a fluid receiving tank fed by said evacuation channel, so as to be able to control the closing of said safety valve (7) as soon as said sensor (6) detects that said security level is reached. 13. The method of claim 12, characterized in that it further comprises the step of equipping said boiler with a condensate lift pump comprising a condensate receiving tray equipped with a detection sensor of a predetermined level of condensate in said receiving pan, which sensor is connected to said control unit.