EP4063759A1 - System for heating water - Google Patents

Abstract

The subject of the invention is a water heating system, comprising a water heater provided (3) with a water tank (4), as well as a heat pump device (2) provided with a condenser, an evaporator, a compressor fluidly connected to each other so as to circulate a refrigerant fluid, the system (1) comprising at least one ignition source (21), and a casing (20) housing said at least one ignition source (21), characterized in that an internal volume of the casing (20) is sized to collect a predetermined quantity of refrigerant in the event of a leak from the latter and in that the casing (20 ) comprises vents (29) for the outlet of the refrigerant from the box (20).

Description

Technical area

The present invention relates to a water heating system, in particular sanitary water, comprising a water heater and a heat pump device.

Prior technique

Nowadays, it is known to equip a dwelling with a system for heating sanitary water intended to supply hot water to the water points of a dwelling. Advantageously, the system comprises a water heater positioned inside the dwelling, equipped with a water tank, as well as a heat pump device, comprising in particular a compressor, a condenser, an expansion valve and a evaporator, forming part of a thermodynamic loop. These two elements are juxtaposed to form a so-called one-piece thermodynamic water heater.

In this thermodynamic loop, a refrigerant circulates which is set in motion and compressed in the compressor, then undergoes condensation in the condenser before being expanded in the expansion valve and finally undergoes evaporation in the evaporator.

The evaporator and the condenser are heat exchangers, in each of which the refrigerant partially exchanges its thermal energy with another fluid. The water tank of the water heater is then heated by the condenser, for example by means of an element wound around the tank.

Until recently, the refrigerant was chosen in flammability class A1, ie non-flammable. This is particularly the case for R134a and R513a fluids. Nevertheless, these gases have a non-negligible, even high, effect on global warming. As a result, the regulations have evolved to encourage the use of fluids with less impact on global warming, in particular less polluting in the sense of global warming. However, these fluids turn out to be flammable, and it is then absolutely necessary to protect the water heating systems against any leakage of this type of refrigerant from the thermodynamic loop to avoid any risk of fire or explosion of the system which could endanger the occupants of the dwelling as well as material goods.

Summary

The present disclosure incorporates the new environmental constraints to limit and/or control, through the design of a heating system, the risks in the event of a leak of the flammable refrigerant.

A water heating system, in particular sanitary water, is proposed, comprising a water heater provided with a water tank, as well as a heat pump device provided with a condenser, an evaporator, a compressor fluidly connected to each other so as to circulate a refrigerant, the heating system comprising a compartment housing the water tank, called the water heater compartment, and a compartment housing at least the evaporator and of the compressor, called the heat pump compartment, the system comprising at least one ignition source, and a casing housing said at least one ignition source, said casing preferably being arranged under a point located at the highest point of the heat pump compartment when the system is installed in a service position, characterized in that an internal volume of the box is dimensioned to collect a predetermined quantity of refrigerant in the event of a leak from the latter and in that the cai sson includes outlet vents for the refrigerant out of the box.

Thus, thanks to the present invention, the box ensures the safety of the ignition sources which are placed out of reach of the refrigerant in the event of a leak thereof.

According to another aspect, the casing comprises a wall, called the rear wall, arranged facing the water heater compartment, the said wall being provided with an opening for passage of the refrigerant in the event of a leak thereof, in particular in the compartment. water heater.

According to another aspect, the casing comprises means for bypassing the casing by the refrigerant in the event of a leak thereof, in particular in the heat pump compartment.

According to another aspect, the casing is delimited by a so-called upper wall, a so-called lower wall, opposite the upper wall, the upper wall being arranged above the lower wall in the service position, the casing also being delimited by a so-called front wall, arranged between the upper wall and the lower wall, at least one of said walls, called curved wall, having a curvature to deflect the refrigerant away from the box, said bypass means comprising said at least one curved wall.

According to another aspect, the heat pump compartment comprises a wall for discharging the refrigerant provided with orifices for discharging the refrigerant.

According to another aspect, the system comprises an electrical connection conduit from the heat pump compartment to the casing, one end of the conduit being placed in the heat pump compartment above a lowest height of the fluid evacuation orifices refrigerant and/or one end of the conduit on the box side being arranged below a lowest height of said at least one source of ignition of the box.

According to another aspect, said at least one ignition source is at least one of an electric heating element and an electronic control means of the heat pump compartment.

According to another aspect, the casing is arranged opposite the water heater compartment and/or under the heat pump compartment.

Brief description of the drawings

• Fig. 1
  [Fig. 1] illustre une vue en perspective d'un système de chauffage d'eau selon la présente invention.
• Fig. 2
  [Fig. 2] illustre une vue en perspective du système de la figure 1, des capots n'étant pas représentés.
• Fig. 3
  [Fig. 3] illustre une vue en perspective d'un détail d'un compartiment pompe à chaleur du système de la figure 2.
• Fig. 4
  [Fig. 4] illustre une autre vue en perspective du détail de la figure 3.
• Fig. 5
  [Fig. 5] illustre une vue en perspective d'un détail d'un caisson du système de la figure 2.
• Fig. 6
  [Fig. 6] illustre une vue en perspective du système de la figure 1, des capots n'étant pas représentés.

Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

• Fig. 1
  [ Fig. 1 ] illustrates a perspective view of a water heating system according to the present invention.
• Fig. 2
  [ Fig. 2 ] illustrates a perspective view of the system of the figure 1 , covers not being shown.
• Fig. 3
  [ Fig. 3 ] shows a perspective view of a detail of a heat pump compartment of the system of the picture 2 .
• Fig. 4
  [ Fig. 4 ] illustrates another perspective view of the detail of the picture 3 .
• Fig. 5
  [ Fig. 5 ] illustrates a perspective view of a detail of a casing of the system of the figure 2 .
• Fig. 6
  [ Fig. 6 ] illustrates a perspective view of the system of the figure 1 , covers not being shown.

Description of embodiments

As emerges from the figures, the subject of the invention is a system for heating water, in particular sanitary water, referenced 1. The heated water is intended to supply a network of ducts in a dwelling.

It is noted that, in the figures, the system 1 is illustrated in a service position, which corresponds to a position in which the system 1 is arranged in or around the dwelling, preferably in a sheltered room, ready to operate. .

To simplify the identification in space, a triplet of orthogonal axes (X, Y, Z) has been drawn on the figures, the axes X and Y being horizontal while the axis Z is vertical, in the service position. of the system. Cylindrical coordinates (r, Θ, z) have also been shown in the figures.

The system 1 notably comprises a heat pump device 2 as well as a water heater 3.

As more particularly visible on the figure 6 , the water heater 3 is provided with a water tank 4, the water of which is heated by the heat pump device 2, as will be detailed later.

As more particularly visible on the figure 3 , 4 , and 6 , the heat pump device 2 is provided with a condenser 5, an evaporator 6, a compressor 7, and an expansion valve (not shown) forming a thermodynamic loop. The heat pump device 2 advantageously comprises a fan 8 to force a flow of air into the evaporator 6. A refrigerant circulates in the thermodynamic loop, in a set of ducts 9 of the device 2.

In a known way, in the loop, the flow of air discharges its calories into the evaporator 6, where the refrigerant circulates, while the refrigerant exchanges all or part of the calories it contains in the condenser, which heats water stored in tank 4.

A refrigerant is chosen whose global warming power (GWP, or "Global Warming Potential") is moderate or even low, advantageously less than or equal to 750, preferably less than or equal to 150. This is for example R 600, R32, R 290, R1234ZE. This type of refrigerant has a gas phase density greater than 1. In other words, when the fluid leaks out of the loop, it tends to descend by gravity.

Nevertheless, the majority of low-GWP fluids turn out to be flammable and the present invention makes it possible to guard against any risk of fire or explosion, as will be described later.

As can be seen from the figures, the system 1 comprises a first compartment 10, hereinafter called the heat pump compartment, and a second compartment 11, hereinafter called the water heater compartment. The heat pump compartment 10 is arranged on the water heater compartment 11 in the service position. In other words, the compartment 10 forms the upper part of the system 1.

On the figure 3 and 4 , the heat pump compartment 10 comprises an envelope 12, a base 13, as well as at least the evaporator 6, the compressor 7, the fan 8, the ducts 9 mounted on the base 13. The envelope 12 and the base 13 form a housing for the elements 6 to 9, preferably of cylindrical shape.

The water heater compartment 11 comprises the water tank 4, the condenser 5, in the form of a coil arranged around the water tank 4, to heat the water contained in the tank 4, as well as an immersed electric heating resistance in the water tank 4 (not shown), also allowing the heating of the water in the tank 4. As can be seen in the figures, the compartment 11 comprises a covering, provided with a cylindrical longitudinal wall 15, elements 4 and 5.

System 1 includes a box 20 which will now be detailed.

The box 20 is separate from each of the compartments 10 and 11.

The casing 20 is arranged under the highest point of the heat pump device 2 in the service position of the system 1. In the illustrated embodiment, the casing 20 is arranged against the trim 15 of the water heater compartment 11.

As best illustrated on the figure 2 , 5 and 6 , the box 20 houses an ignition source 21 which is a means for electrically controlling the heating resistor and/or the heat pump device 2. In the illustrated embodiment, the means 21 is in the form of a a printed circuit board provided with electronic power components.

As indicated above, the control means 21 constitutes what is called a source of ignition or ignition, that is to say that, due to the local heating of the air generated by the operation of the electronic components of the control means 21 or of a spark linked to an unsealed electrical contact, there is a risk of ignition of the refrigerant in the event of a leak thereof. Note that hot spots of the non-immersed heating element type also constitute a source of ignition. Once the auto-ignition temperature is reached, the fluid ignites, even in the absence of an electrical contact type.

Preferably, the box 20 is shaped so that its internal volume is sized to collect a predetermined quantity of refrigerant in the event of a leak.

The box 20, distinct from the compartments 10 and 11, and its adapted volume, provide protection for the ignition source 21 by creating a buffer zone in the event of a refrigerant leak.

As is particularly apparent from figure 2 and 5 , the box 20 is delimited by two opposite walls, front and rear, 22, 23, two opposite walls, upper and lower, 24, 25 and two opposite side walls, 26, 27. The rear wall 23 is arranged against the wall longitudinal length of the casing 15 of the water heater compartment 11.

The front and rear walls, 22, 23, extend substantially in a vertical plane (Θ, z).

The rear wall 23 is provided with an opening 28 for fluid communication between the interior of the compartment 11 and the box 20. In the illustrated embodiment, the opening 28 is circular. Nevertheless, other forms are possible. The longitudinal wall of the casing 15 is provided with a similar opening, which ensures that a refrigerant leak can be evacuated from the water heater compartment 11 into the box 20.

As it appears from the figure 5 , the printed circuit board 27 is arranged in the upper part of the rear wall 23 while the opening 28 is arranged in the lower part of the rear wall 23. Thus, the internal volume of the box 20 is divided into a volume of the part top, including the map 27 and a volume of the lower part, including the opening 28. On the figure 5 , the volume of the upper part is referenced V1 and the volume of the lower part V2. An interface I delimits the volume V1 on the one hand and the volume V2 on the other hand. The interface is not perfectly sealed because junctions are available between the two volumes (notably cable passage).

The box 20 also includes vents 29 for evacuating refrigerant from the box 20.

The size of the vents, their shape, their spacing, their positions in the walls of the box 20 are chosen so as to allow the flow of the entire charge of refrigerant in a given time, preferably less than 5 min.

To do this, several parameters are taken into account, including the density of the refrigerant, the flow rate of the leak, the state (off or in operation) of the system (if the fan in the heat pump compartment is on, this creates a depression), natural or forced ventilation in the environment of system 1, and the volume of the box.

In the illustrated embodiment, the vents 29 are holes drilled in the bottom wall 25, rectangular in shape and parallel to each other. Nevertheless, it is also possible to envisage positioning the vents in the front wall and/or the side walls.

Note that the vents are dimensioned so as to prevent access to the control means 21 by a user (test finger).

Curved parts 30, 31 provide a junction between the upper wall 24 and each of the side walls 26, 27. Similarly, curved walls 32, 33 provide a junction between the lower wall 25 and each of the side walls 26, 27.

The front and rear walls, 22, 23 have a generally rectangular shape, the corners of which are curved according to the curvature of the curved parts 30, 31, 32, 33.

Preferably, the casing 20 comprises means 34 for bypassing the casing 20 by the refrigerant in the event of a leak thereof. In the illustrated embodiment, the bypass means 34 comprise the junction parts 30, 31 between the top wall 24 and the side walls 26, 27.

If refrigerant escapes from the heat pump device 2, for example through the interior of the heat pump compartment 10 into the interior of the water heater compartment 11, or directly from the condenser 5 of the water heater compartment 11 (arrows F2 on the figure 6 ), the fluid accumulates by gravity in the lower part of the water heater compartment 11 until it reaches the height of the opening 28, through which the fluid leaves the compartment 11 and enters the box 20. Again by gravity, the fluid descends into the box 20 until it evacuates the box 20 through the vents 29.

If refrigerant escapes from the heat pump device 2 from outside the compartment 10 (arrows F1 on the figure 1 ), the bypass means 34 prevents the fluid from entering the box 20.

As it appears from the figure 6 , the system 1 also comprises a profile 35 inside which at least one electric cable ensures the connection between the control means 21 of the heat pump device 2 and the heat pump compartment 11. A lower end 35-1 of the profile 35 is arranged in the water heater compartment 11 and one end 35-2 of section 35 is placed in the heat pump compartment 10.

Compartment 10 can also be provided with ignition sources 40. These are for example capacitors, wiring, electronic elements.

Advantageously, the heat pump compartment 10 comprises a wall 36 for evacuating the refrigerant provided with orifices 37 for evacuating the refrigerant, also called huis.

In the figures, the wall 36 extends vertically around certain elements of the compartment 10, the evaporator 6 and the fan 8 in particular. The wall 34 has a section curved along an arc of a circle, for example a semicircle. The wall 34 is advantageously placed on the base 13 and has a height slightly less than a height of the envelope 12.

In the illustrated embodiment, the orifices 37 are identical and uniformly distributed in the wall 36. Of course, the invention is not limited to this arrangement and it is possible to envisage orifices of dimensions and/or shapes different from each other. others, and/or distributed unevenly in the wall 36.

In the illustrated embodiment, the orifices 37 are arranged at the interface between the heat pump compartment 10 and the exterior of the system 1. Alternatively, a set of pipes lead the fluid to the orifices arranged at a lower point. of compartment 10 with no sources of ignition.

The heat pump compartment 10 also comprises at least one wall for protecting the ignition sources present in the compartment 10. The protective wall(s) have a higher height than the height of the lowest orifices. On the figure 3 and 4 , the compartment 10 comprises a set 38 of protective walls, including a flat wall 39 flat.

Thus, in the event of a leak of flammable refrigerant with a density greater than 1 in the heat pump compartment, the fluid cannot reach the sources of ignition because it will be evacuated beforehand through the orifices 37, thus preventing any risk of ignition between the ignition sources and the fluid.

Advantageously, the upper end 35-2 of the profile 35 is arranged in the heat pump compartment 10 above the lowest height of the orifices 37. This arrangement makes it possible to prevent the refrigerant from escaping from the compartment 10 in profile 29.

It is noted that advantageously, according to a variant not shown, the lower end 35-1 of the conduit 35 on the box side is arranged below a lowest height of the ignition source 21 of the box 20.

The existence of the casing 20, separate from the heat pump compartment 10, housing the ignition sources 21, the calibration of the interior volume of the casing 20 and its positioning around the water heater compartment drastically reduce the risks of ignition and blast.

In addition, the rear, side and top faces being designed in such a way as to guide the fluid around the box 20, there is a very strong limitation of the penetration of fluid into the box 20, which ensures that the concentration of refrigerant fluid remains lower. at a threshold value that would trigger an ignition under the operating conditions of system 1.

In addition, the opening between the casing 15 and the casing 20 makes it possible to avoid trapping fluid under the casing and to evacuate the fluid through the opening, then the vents of the casing 20.

An exemplary embodiment is as follows: the refrigerant is R290 (generic name propane). The total amount of fluid in system 1 is 150g maximum, preferably 130g.

The box 20 has dimensions of 460 mm×235 mm×55 mm.

Its internal volume, with all the components, is 4.5 L, distributed as follows: volume of the lower part of 3.1 L and volume of the upper part 1.4 L.

Tests by the Applicant have shown that the box 20 thus shaped ensures evacuation of the entire volume of fluid in less than 300 seconds. This evacuation takes place under the most critical conditions: a clean rupture of the condenser.

In this case, the lower zone of the box 20 can contain 5g out of the 130g of the product, ie 4%.

As already apparent from the preceding description, the invention resides in the creation of a zone positioned under the highest point of the heat pump circuit in such a way that the ignition sources can be installed there without possible contact with refrigerant from any leak.

• L'ensemble des cas de fuite est traité (sous l'habillage ou au niveau du compartiment pompe à chaleur) ; En cas de fuite de fluide d'un élément dans le compartiment chauffe-eau 11, la fuite s'échappe par le caisson 20. En cas de fuite de fluide d'un élément dans le compartiment pompe à chaleur 10, la fuite ne peut pénétrer le conduit électrique, s'échappe par les huis 37 du compartiment pompe à chaleur et contourne le caisson nouvellement défini, empêchant ainsi le contact avec les sources d'ignition.
• Le système 1 ne nécessite pas de zones parfaitement étanches. En effet, il est difficile de réaliser de manière reproductible en grande série une étanchéité performante. De plus, une étanchéité peut être détériorée durant la vie du produit du fait d'un vieillissement des matières ou par manipulation par l'utilisateur. Dans le cas présent, le niveau d'étanchéité à atteindre est faible (pas de pression) et il suffit d'une lèvre ou d'un guide pour assurer la gestion du flux de fluide ;
• Les sources d'allumage peuvent être positionnées librement dans toute la hauteur du produit et donc de manière préférentielle à proximité des éléments nécessitant un apport en énergie ou en régulation. Cette solution permet de limiter la complexité du circuit électrique et d'offrir davantage de flexibilité aux différentes contraintes de fabrication d'un chauffe-eau thermodynamique ;
• Le positionnement des sources d'allumage à une hauteur inférieure au point le plus haut du circuit frigorigène permet notamment davantage de compacité du produit, engendrant une réduction des contraintes client, des contraintes transport et une réduction des coûts globaux (capotage, conditionnement, etc...).

The present invention makes it possible to overcome the risks of explosion caused by the ignition of a flammable refrigerant with the following advantages:

• All cases of leaks are dealt with (under the casing or at the level of the heat pump compartment); In the event of a fluid leak from an element in the water heater compartment 11, the leak escapes through the casing 20. In the event of a fluid leak from an element in the heat pump compartment 10, the leak cannot penetrate the electrical conduit, escapes through the doors 37 of the heat pump compartment. heat and bypasses the newly defined casing, preventing contact with ignition sources.
• System 1 does not require perfectly sealed areas. In fact, it is difficult to produce high-performance sealing in a large series in a reproducible manner. In addition, sealing can be damaged during the life of the product due to aging of the materials or by handling by the user. In the present case, the level of tightness to be achieved is low (no pressure) and a lip or a guide is sufficient to manage the flow of fluid;
• The ignition sources can be positioned freely throughout the height of the product and therefore preferably close to the elements requiring a supply of energy or regulation. This solution makes it possible to limit the complexity of the electrical circuit and to offer more flexibility to the various manufacturing constraints of a thermodynamic water heater;
• The positioning of the ignition sources at a height lower than the highest point of the refrigerant circuit allows in particular more compactness of the product, generating a reduction in customer constraints, transport constraints and a reduction in overall costs (covering, packaging, etc.). ..).

It is noted that the protective walls can take various forms and in particular: sealed compartment on the side faces with or without cowling, the upper part, tube, profile, guide etc...

Claims (8)

Water heating system, in particular sanitary water, comprising a water heater provided (3) with a water tank (4), as well as a heat pump device (2) provided with a condenser (5), an evaporator (6), a compressor (7) fluidically connected to each other so as to circulate a refrigerant fluid, the heating system (1) comprising a housing compartment for the water tank, said compartment water heater (11), and a compartment housing at least the evaporator and the compressor, said heat pump compartment (10), the system (1) comprising at least one ignition source (21, 40) , and a casing (20) housing said at least one ignition source (21, 40), said casing (20) preferably being arranged under a point located at the highest point of the heat pump compartment (10) when the system (1) is installed in a service position, characterized in that an internal volume of the box (20) is dimensioned to collect a predetermined quantity of refrigerant in the event of leakage thereof and in that the casing (20) comprises vents (29) for the exit of the refrigerant from the casing (20). System according to Claim 1, in which the casing comprises a wall, called the rear wall (23), arranged opposite the water heater compartment (11), the said rear wall (23) being provided with an opening (28) for passage refrigerant in the event of a leak. System according to one of the preceding claims, in which the casing (20) comprises means (34) for bypassing the casing (20) by the refrigerant in the event of a leak from the latter. System according to the preceding claim, in which the box (20) is delimited by a so-called upper wall (24), a so-called lower wall (25), opposite the upper wall, the upper wall being arranged above the bottom wall (25) in the service position, the box (20) also being delimited by a so-called front wall (22), arranged between the top wall (24) and the bottom wall (25), and side walls ( 26, 27) arranged on either side of the front wall (22), at least one of said walls, called curved wall, having a curvature (30, 31, 32, 33) to deflect the refrigerant away of the box (20), said bypass means (34) comprising said at least one curved wall. System according to one of the preceding claims, in which the heat pump compartment (10) comprises a wall for evacuating the refrigerant provided with orifices (37) for evacuating the refrigerant. System according to the preceding claim, comprising a conduit (35) for electrical connection from the heat pump compartment (10) to the box (20), one end (35-2) of the conduit (35) being placed in the heat pump compartment ( 10) above a lowest height of the refrigerant discharge orifices (37) and/or one end of the box-side duct (35-1) being arranged below a lowest height of said at least one ignition source (21) of the box (20). System according to one of the preceding claims, in which the said at least one ignition source (21) is at least one of an electrical heating element control means and an electronic heat pump compartment control means . System according to one of the preceding claims, in which the box (20) is arranged opposite the water heater compartment (11) and/or under the heat pump compartment (10)

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