FR3145030A3 - HEAT PUMP SYSTEM COMPRISING A DEGASSING DEVICE AND SUPPLEMENTARY HEATING - Google Patents

Abstract

The present invention relates to a heat pump system (1) comprising at least one refrigeration circuit (2) in which a refrigerant circulates and operates on the primary side (24) of a main heat exchanger (21) and a conditioning circuit (3) in which a technical fluid, used for heating/cooling functions of premises and/or for the production of domestic water, circulates and operates on the secondary side (25) of said main heat exchanger (21 ). The conditioning circuit (3) further comprises a circulation pump (30) and at least one auxiliary heater (5). This auxiliary heater (5) integrates at least one ventilation valve (6) capable of expelling at least refrigerant leaks before they spread into said conditioning circuit (3). Figure for the abstract: [Fig. 3].

Description

HEAT PUMP SYSTEM COMPRISING A DEGASSING DEVICE AND A SUPPORTING HEATER

The present invention relates to a heat pump system for the heating/cooling functions of premises and/or for the production of sanitary water, preferably operating with a refrigerant with low environmental impact and designed to prevent any refrigerant leakage from reaching the environment in which said heat pump system is installed and/or operates, and from spreading therein.

More specifically, the present invention relates to a heat pump system for the heating/cooling functions of premises and/or for the production of sanitary water capable of integrating a device adapted to intercept and expel said possible refrigerant leaks without this leading to an increase in the overall number of functional components of said heat pump.

Without any limiting intention, the invention relates to the sector of heat pump conditioning equipment for residential and/or industrial/commercial (or similar) buildings, where "conditioning" is indifferently designated as "heating" or "cooling", preferably by electrical power.

Of course, nothing prevents the heat pump system of the invention from being extended, with minimal adaptations within the reach of those skilled in the art, to sectors similar to those of heating and/or cooling equipment for premises, for example in the context of heat pumps for the production of domestic water.

• un circuit de réfrigération 2' dans lequel un réfrigérant est évaporé à basse température, porté à haute pression, condensé et finalement ramené à une pression d'évaporation, et
• un circuit pour le fluide technique 3', généralement de l'eau ou un fluide similaire, destiné au chauffage/refroidissement des locaux par l'intermédiaire de radiateurs, de panneaux radiants au sol, de ventilo-convecteurs ou autres et/ou à la production d'eau chaude sanitaire par l'intermédiaire d'accumulateurs de chaleur spéciaux, par exemple par l'intermédiaire d'accumulateurs d'eau chaude.

It is known that a heat pump system 1' comprises at least (see ) :

• a refrigeration circuit 2' in which a refrigerant is evaporated at low temperature, brought to high pressure, condensed and finally returned to an evaporation pressure, and
• a circuit for the technical fluid 3', generally water or a similar fluid, intended for heating/cooling premises by means of radiators, underfloor radiant panels, fan coils or the like and/or for the production of domestic hot water by means of special heat accumulators, for example by means of hot water accumulators.

Subsequently, for reasons of descriptive simplicity, the circuit 3' of the technical fluid will be called "conditioning circuit 3'", where, as already mentioned, the term "conditioning" indifferently designates the function of cooling/heating premises and the function of heating domestic water.

Generally, the refrigeration circuit and the conditioning circuit share at least one heat exchanger 21', for example a plate exchanger 21', in which the heat exchange between said refrigeration and the technical fluid takes place.

More specifically, when a heat pump system 1' is used to heat the environment and/or sanitary water, said heat exchanger 21' operates as a condenser. On the contrary, if the same heat pump system 1' operates in cooling mode, said heat exchanger 21' operates as an evaporator.

The conditioning circuit 3' of a heat pump system 1' may also comprise at least one auxiliary heater 5', generally intended to provide additional heating capacity for the technical fluid and/or to protect the heat pump system against freezing during cold periods of operation.

It is known that the development of heat pumps must face a plurality of challenges, both technical and environmental.

On the one hand, in fact, it is desirable that the heat pump continues to operate as efficiently as possible, while on the other hand it is increasingly desirable to avoid the use of polluting refrigerants in order to reduce risks to the environment (for example, for contrasting phenomena such as global warming).

To achieve these goals, the most polluting refrigerants, such as R410A, are gradually being replaced by others with a low impact on the environment (i.e. with a low "global warming potential" or " GWP "). For example, heat pumps are increasingly operating with refrigerants belonging to the group of hydrofluorocarbons and/or aliphatic hydrocarbons such as, without any limiting intention, propane R290 (chemical formula: C ₃ H ₈ ) or R32 (a difluoromethane with the chemical formula CH ₂ F ₂ ).

These refrigerants (or others belonging to the same families or similar groups), although having a low impact on the environment, are not without drawbacks.

In fact, it is known that low environmental impact refrigerants are generally highly flammable.

Therefore, when transitioning from traditional refrigerants to low-GWP refrigerants, it has been necessary to pay greater attention to their flammability and related issues.

For example, European and/or national regulations have been issued which provide that any refrigerant leak, and its subsequent passage from the refrigeration circuit to the conditioning circuit, must be intercepted and blocked before it reaches the space heating and/or cooling system or the domestic water production system.

For example, as shown in US 2019/0390873 A1, said heat pumps may provide airtight chambers in which any refrigerant leaks may remain confined without risk of flammability or dispersion into the environment of said heat pump and/or be connected to pipes suitably designed to convey said refrigerant leaks directly into the atmosphere.

For this purpose, deaerators, appropriately placed in the heat pump system, have been developed to separate and possibly expel refrigerant leaks due to breakages and/or malfunctions in the components and/or pipes of the refrigeration circuit. These breakages and/or malfunctions can in fact allow the refrigerant to infiltrate and reach the conditioning circuit, mixing with the technical fluid.

As shown in the , taking as reference the direction of operation of the technical fluid in the conditioning circuit 3', a degasser 4' is positioned immediately downstream of the heat exchanger 21' responsible, as expected, for the heat exchange between the refrigerant of the refrigeration circuit 2' and the technical fluid (technical water or similar) of the same conditioning circuit 3'.

As will be referred to several times during the present description, it is specified that by "direction of operation" or "operating flow" is meant the direction normally imparted to the technical fluid in the conditioning circuit 3' by the corresponding circulation pump 30', when the heat pump system operates in heating and/or cooling conditions (see reference F in the or 3).

For example, said degasser 4' may be positioned between said heat exchanger 21' and said auxiliary heater 5', if applicable.

A known type of degasser 4' is illustrated in Figures 1 and/or 2a, 2b.

Said degasser 4' has a shape and dimensions suitable for defining a chamber 40', called "degassing chamber 40'", into which the technical fluid of the conditioning circuit 3', which passes through it, can flow and propagate while reducing its speed.

Due to this slowdown, the driving force of the technical fluid towards the refrigerant leaks also decreases, which promotes the interception and separation of these leaks.

Any separation device 43' inside the degassing chamber 40', such as mesh filters (as well illustrated in Figures 2a or 2b), perforated meshes, baffles, turbulators or similar means interfering with the flow of the technical fluid, can facilitate the slowing down of the latter and the aforementioned separation of the refrigerant.

Once separated, the refrigerant, generally in the gaseous state (for example in the form of bubbles B) and of lower density than that of the technical fluid, tends to rise towards the upper parts of the degassing chamber 40' from where at least one ventilation valve 6' allows it to be evacuated into the atmosphere before it reaches and spreads into the environment in which the heat pump system 1' is installed and/or operates (with the resulting disadvantages and dangers for the user).

It is not necessary to dwell on the description of the details and the technical and functional characteristics of said degasser 4' since it is, as mentioned, a component per se already known to the person skilled in the art, widely used and available in a wide variety of designs and construction variants (see, in this regard, also the variant described and shown in the prior art document EP 4 075 078 A1 and/or the degasser of document US 6 526 921 B1).

In this context, however, it is necessary to clarify that a 4' degasser constitutes an additional component for a 1' heat pump system which can have a negative influence on the production and installation costs, as well as on the size and bulk of the latter, in particular of the external unit, where it is generally housed.

Furthermore, while on the one hand the use of a 4' degasser increases the safety of a heat pump system against possible refrigerant leaks, on the other hand it introduces and generates high localised pressure losses and therefore significant resistance to the circulation of the technical fluid in the 3' conditioning circuit, consequently deteriorating the efficiency of the entire 1' system.

There is also an increased risk of technical fluid leaks from the 3' conditioning circuit if the hydraulic connections between the pipes concerned and the 4' degasser are not perfectly sealed. This can lead to increased management and maintenance costs for the 1' heat pump system.

In an attempt to overcome these problems, attempts have therefore been made to study, without success, a more efficient degassing device, for example of the type illustrated in documents CN 101 970 940 A and/or EP 2 312 224 B1, according to the preamble of the independent claim attached to the present description.

The object of the present invention is to avoid this type of drawbacks by proposing a heat pump system with low environmental impact for the heating/cooling functions of premises and/or for the production of sanitary water comprising at least one highly efficient device capable of preventing any refrigerant leak from spreading inside the installation and/or the environment of use.

Another objective of the present invention, at least for one of its executing variants, is to provide a heat pump system with low environmental impact for the heating/cooling functions of premises and/or for the production of sanitary water in which said at least one device adapted to intercept such refrigerant leaks does not cause an increase in the pressure losses and the resistance to the flow of the technical fluid of said heat pump system.

Another object of the present invention, at least for one of its executing variants, is to provide a heat pump system with low environmental impact for the functions of heating/cooling premises and/or for the production of sanitary water, capable of integrating at least one device adapted to intercept such refrigerant leaks without this leading to an increase in the total number of functional components of said heat pump system.

These and other objectives, which will become clear hereinafter, are achieved by a heat pump system conforming to the independent claims.

Other objectives can also be achieved by additional features of dependent claims.

• La montre schématiquement un système de pompe à chaleur pour les fonctions de chauffage/refroidissement de locaux et/ou pour la production d'eau sanitaire selon l'état de la technique ;
• Les figures 2a et 2b montrent schématiquement un détail du système de pompe à chaleur de la , en particulier un dispositif de dégazage connu, selon une première et une deuxième configuration de fonctionnement ;
• La montre schématiquement un système de pompe à chaleur pour les fonctions de chauffage/refroidissement de locaux et/ou pour la production d'eau sanitaire selon l'invention ;
• La montre schématiquement un détail du système de pompe à chaleur de la , en particulier du dispositif de dégazage de l'invention.

Other features of the present invention will be better illustrated by the following description of a preferred embodiment, in accordance with the claims of the patent and illustrated, by way of non-limiting example, in the accompanying drawing tables, in which:

• There schematically shows a heat pump system for room heating/cooling functions and/or for the production of domestic water according to the state of the art;
• Figures 2a and 2b schematically show a detail of the heat pump system of the , in particular a known degassing device, according to a first and a second operating configuration;
• There schematically shows a heat pump system for the heating/cooling functions of premises and/or for the production of sanitary water according to the invention;
• There schematically shows a detail of the heat pump system of the , in particular of the degassing device of the invention.

The features of at least one preferred variant of the heat pump system for the space heating/cooling functions and/or for the production of sanitary water of the invention are now described, using the references contained in the figures.

Reference number 1 therefore indicates, as a whole, the heat pump system of the invention which can be used for heating and/or cooling functions in a domestic or non-domestic (e.g. commercial or industrial) environment and/or for the production of sanitary water, e.g. domestic hot water.

As already partially mentioned, the heat pump system 1 has a first circuit 2 in which a refrigerant circulates which is evaporated at low pressure, brought to high pressure, condensed and finally brought back to an evaporation pressure, and a second circuit 3 crossed by a technical fluid, preferably technical water, which can be used for heating/cooling the premises and/or for producing domestic water.

Subsequently, for reasons of descriptive simplicity, the first 2 and second 3 circuits of the heat pump system 1 of the invention will be respectively called "refrigeration circuit 2" and "conditioning circuit 3", the term "conditioning" designating indifferently the function of cooling/heating an environment and the function of heating domestic water, as indicated previously.

Preferably, without any limiting intention, said refrigeration circuit 2 and conditioning 3, the latter at least partially, can be housed in the external unit 10 of the heat pump system 1.

In this description, the refrigerant will be referred to, without any limiting intention, as a refrigerant with low environmental impact (e.g. low GWP - global warming potential ) which, as mentioned, has a higher flammability risk, such as, for example, the well-known R290 ( propane ), R32 ( difluoromethane ), or the like.

• au moins un premier échangeur de chaleur 20,
• au moins un deuxième échangeur de chaleur 21,
• au moins un compresseur 22 placé entre le premier 20 et le second 21 échangeur de chaleur et conçu pour comprimer le fluide frigorigène entre une pression minimale et une pression maximale,
• au moins une soupape de laminage 23 qui réalise une expansion, à une enthalpie sensiblement constante, et un refroidissement du fluide frigorigène.

As shown in the , the refrigeration circuit 2 includes special pipes connected together:

• at least one first heat exchanger 20,
• at least one second heat exchanger 21,
• at least one compressor 22 placed between the first 20 and the second 21 heat exchanger and designed to compress the refrigerant between a minimum pressure and a maximum pressure,
• at least one throttling valve 23 which achieves expansion, at a substantially constant enthalpy, and cooling of the refrigerant fluid.

Said refrigerant circuit 2 can be switched, by means of a switching valve (not shown), for example in the "4 directions" between the "cooling" operating mode and the "heating" operating mode (and vice versa) with said first 20 and second 21 heat exchanger which can therefore operate, if necessary, either as a condenser or as an evaporator.

In "heating" mode, the refrigerant dissipates heat, by condensing, in the second exchanger 21 which therefore plays the role of condenser, while absorbing heat, by evaporating, in the first exchanger 20 which plays the role of evaporator.

On the contrary, in "cooling" mode, the first heat exchanger 20 mentioned above operates as a condenser of the refrigeration circuit 2, while the second exchanger 21 as a relative evaporator.

More generally, the second heat exchanger 21 is preferably the one in which the heat exchange takes place between the refrigerant of the refrigeration circuit 2 and the technical fluid of the conditioning circuit 3.

For the sake of clarity, this second heat exchanger 21 is called the "main heat exchanger" or, more simply, "main exchanger".

• comme un évaporateur et, dans ce cas, le fluide frigorigène absorbe, à pression sensiblement constante, l'énergie thermique du fluide technique en le refroidissant, ou
• comme condenseur et dans ce cas, le fluide frigorigène cède, à pression sensiblement constante, une partie de son énergie thermique au fluide technique, en le chauffant.

If necessary, the main heat exchanger 21 can therefore operate:

• as an evaporator and, in this case, the refrigerant absorbs, at substantially constant pressure, the thermal energy of the technical fluid by cooling it, or
• as a condenser and in this case, the refrigerant fluid gives up, at a substantially constant pressure, part of its thermal energy to the technical fluid, by heating it.

Therefore, it may be possible to identify, in this main heat exchanger 21, a primary side 24 where the refrigerant circulates and operates, and a secondary side 25 where the technical fluid of the conditioning circuit 3 circulates and operates.

As expected, the conditioning circuit 3 may also comprise at least one circulation pump 30 of the technical fluid and is connected and/or cooperates with one or more terminals (not shown) for ambient heating/cooling and/or for sanitary water.

• comme dispositifs de dissipation de la chaleur et/ou comme unités de conditionnement en mode chauffage/refroidissement, comprenant dans ce cas, par exemple, un ou plusieurs radiateurs, panneaux radiants au sol ou muraux, ventilo-convecteurs, convecteurs ou dispositifs similaires, et/ou
• comme accumulateurs de chaleur contenant le fluide circulant dans le circuit de conditionnement 3, par exemple comme tampons, et/ou
• comme accumulateurs de chaleur, par exemple comme réservoirs d'eau chaude (ou similaires) dans le cas du chauffage de l'eau sanitaire.

The said terminals can therefore operate:

• as heat dissipation devices and/or as air conditioning units in heating/cooling mode, in this case comprising, for example, one or more radiators, floor or wall radiant panels, fan coils, convectors or similar devices, and/or
• as heat accumulators containing the fluid circulating in the conditioning circuit 3, for example as buffers, and/or
• as heat accumulators, for example as hot water tanks (or similar) in the case of heating domestic water.

Without any limiting intention and considering the operating direction F of the technical fluid as a reference, the circulation pump 30 can be placed upstream of the secondary side 25 of the main heat exchanger 21 (see ).

• une soupape de décharge (non représentée) capable de s'ouvrir pour des pressions du fluide technique supérieures à un seuil de sécurité, généralement de 3 bars, permettant son évacuation ; cette condition peut se produire en cas d'anomalies et/ou de défaillances majeures d'un ou de plusieurs composants du système de pompe à chaleur 1, par exemple en présence de fuites importantes et soudaines de réfrigérant du circuit frigorifique 2 dues à des ruptures de l'échangeur principal 21 de ce dernier (en général, l'échangeur à plaques) et/ou des tuyaux de raccordement, et/ou
• au moins une soupape de ventilation 6, de type manuel ou automatique, qui permet l'évacuation d'un gaz éventuellement transporté par le fluide technique et convenablement intercepté et séparé de celui-ci.

The conditioning circuit 3 may further comprise at least:

• a relief valve (not shown) capable of opening for pressures of the technical fluid above a safety threshold, generally 3 bars, allowing its evacuation; this condition may occur in the event of anomalies and/or major failures of one or more components of the heat pump system 1, for example in the presence of significant and sudden leaks of refrigerant from the refrigeration circuit 2 due to ruptures of the main exchanger 21 of the latter (in general, the plate exchanger) and/or of the connecting pipes, and/or
• at least one ventilation valve 6, of the manual or automatic type, which allows the evacuation of a gas possibly transported by the technical fluid and suitably intercepted and separated from it.

• des fuites de réfrigérant provenant du circuit de réfrigération 2 et qui ont atteint et affecté le fluide technique, et/ou éventuellement
• de l'excès d'air présent dans les tuyaux et/ou dans les terminaux dudit circuit de conditionnement 3.

In the example, said ventilation valve 6 can therefore allow the expulsion of:

• refrigerant leaks from refrigeration circuit 2 which have reached and affected the technical fluid, and/or possibly
• excess air present in the pipes and/or in the terminals of said conditioning circuit 3.

As shown in the , said conditioning circuit 3 further comprises an auxiliary heater 5, intended to provide additional heating capacity for the technical fluid and/or to protect the heat pump system 1 against freezing during the coldest operating periods.

Generally, said auxiliary heater 5 is a substantially box-shaped body in fluid communication with the pipes of the conditioning circuit 3 and it is therefore also crossed by the technical fluid.

• une entrée 51 reliée, par des sections de tuyaux, au côté secondaire 25 de l'échangeur de chaleur principal 21,
• une sortie 52 reliée au tuyau de refoulement 31 pour les terminaux du circuit de conditionnement 3,
• une chambre 50 dans laquelle a lieu le chauffage supplémentaire du fluide technique (ci-après également appelée "chambre de chauffage 50"),
• au moins un élément chauffant 53, à l'intérieur de ladite chambre 50, et, de préférence, de type électrique (c'est-à-dire de nature à chauffer ce fluide technique par effet Joule).

Without any limiting intention, the auxiliary heater 5, which is preferably installed downstream of the main heat exchanger 21 (referring to the operating direction F of the technical fluid) comprises at least:

• an inlet 51 connected, by pipe sections, to the secondary side 25 of the main heat exchanger 21,
• an outlet 52 connected to the discharge pipe 31 for the terminals of the conditioning circuit 3,
• a chamber 50 in which the additional heating of the technical fluid takes place (hereinafter also referred to as "heating chamber 50"),
• at least one heating element 53, inside said chamber 50, and, preferably, of the electric type (i.e. of a nature to heat this technical fluid by Joule effect).

According to a possible embodiment, said at least one heating element 53 may for example comprise one or more electric heating elements (also called "resistors"), each comprising for example a tubular element, generally metallic, wound and folded several times on itself so as to form a plurality of coils or branches 54, adjacent, preferably close to each other (see, for example, figures 3 and/or 4).

Naturally, there is nothing to prevent the adoption of alternative or equivalent electric heating elements among those currently available on the market.

Due to structural, geometric and dimensional affinities, it was considered advantageous, according to the invention, to use said at least one auxiliary heating device 5 also as a "degassing device".

According to the invention, the auxiliary heater 5 therefore also fulfils a degassing function and can therefore intercept and/or expel at least the refrigerant leaks before they spread into the conditioning circuit 3, preventing them from reaching the pipes, collectors, valves, radiators or fan coils or any other device in the technical fluid distribution circuit inside a building.

• le volume de la chambre de chauffage 50 agit également, et si nécessaire, comme une "chambre de dégazage" dans laquelle, comme dans les dispositifs de dégazage traditionnels et connus (voir réf. 40' dans la de l'état de la technique), le fluide technique peut se propager, en diminuant sa vitesse et la force d'entraînement d'éventuelles fuites de réfrigérant, favorisant ainsi la séparation de celles-ci,
• les éléments chauffants 53, à l'intérieur de ladite chambre de chauffage 50, par exemple leurs bobines ou branches 54 (ou configurations similaires), fonctionnent comme des "dispositifs séparateurs" capables d'interférer avec le fluide technique et de le ralentir davantage, en améliorant la séparation susmentionnée des fuites de réfrigérant, équivalente à celle obtenue par les filtres à mailles, les écrans perforés, les ailettes, les ralentisseurs, les déflecteurs, les turbulateurs (ou similaires) des dégazeurs de l'état de l'art (voir réf. 43' dans les -2b).

To this end, according to a possible embodiment of the invention, which is part of the preferred embodiments, the auxiliary heater 5 integrates at least the aforementioned ventilation valve 6 of the conditioning circuit 3, whereas:

• the volume of the heating chamber 50 also acts, and if necessary, as a "degassing chamber" in which, as in traditional and known degassing devices (see ref. 40' in the of the state of the art), the technical fluid can propagate, reducing its speed and the driving force of possible refrigerant leaks, thus promoting their separation,
• the heating elements 53, inside said heating chamber 50, for example their coils or branches 54 (or similar configurations), function as "separator devices" capable of interfering with the technical fluid and slowing it down further, improving the aforementioned separation of refrigerant leaks, equivalent to that obtained by mesh filters, perforated screens, fins, retarders, deflectors, turbulators (or the like) of state-of-the-art deaerators (see ref. 43' in the -2b).

Furthermore, given the known tendency of the refrigerant separated from the technical fluid to rise (for example in the form of bubbles B) under the effect of its lower density, the ventilation valve 6, which, as has been seen, can be automatic or manual, is preferably installed at or near the upper wall 56 of the auxiliary heater 5 and in fluid communication with the heating chamber 50 of the latter.

Said ventilation valve 6 is capable of remaining closed (or closing) in the absence of refrigerant leaks or for modest or tolerable quantities thereof, or of opening when said quantity of refrigerant separated from the technical fluid exceeds significant and no longer negligible values.

As an example, said ventilation valve 6 may consist of a jolly type valve known and already used for the expulsion of excess air which may be present in a heating/cooling system.

Therefore, although the use and operation of the ventilation valve 6 are described hereinafter mainly in relation to refrigerant leaks, nothing prevents everything said on this subject from being fully and easily extended to the evacuation of excess air in the conditioning circuit 3. In other words, unless otherwise indicated, the term "refrigerant leaks" is to be understood, at least by analogy or similar behavior, also as the excess air to be intercepted and removed from the conditioning circuit 3.

Generally speaking, the auxiliary heater 5, comprising said ventilation valve 6, can therefore, by its structure, facilitate the evacuation of any gas intercepted and separated from a fluid and therefore also allow the elimination of said excess air in the technical fluid.

Without any limiting intention, and without prejudice to the possibility of using equivalent solutions, said ventilation valve 6 can be of the automatic type, where the opening of a relative vent 64, intended to evacuate, for example into the atmosphere, the refrigerant intercepted and separated from the technical fluid, is entrusted to a shutter 60, which can be actuated according to the presence and quantity of said refrigerant.

For example, as illustrated in the , the shutter 60 may be housed inside a compartment or valve body 61 in fluid communication with the underlying heating chamber 50 of the auxiliary heater 5 and is generally in contact and/or cooperates with the technical fluid which fills and/or passes through the same chamber 50.

According to a possible executive variant, said shutter 60 can be connected, by a special return means 62 (for example a control rod 62) to a float 63 capable of floating in the technical fluid of the heating chamber 50.

Typically, said vent valve 6 is "normally closed", i.e. the shutter 60 is positioned so as to keep the vent 64 closed, but capable of opening immediately in the event of refrigerant leaks, thereby changing from a "closing configuration" to an "opening configuration".

• en l'absence de fuites de réfrigérant, ou pour des quantités modestes, le flotteur 63 est normalement situé à proximité de la paroi supérieure 65 de la soupape de ventilation 6 et l'obturateur relatif 60 maintient fermé ou ferme l'évent 64, alors que le flotteur 63 est situé à proximité de la paroi supérieure 65 de la soupape de ventilation 6,
• en cas de fuites, le réfrigérant qui a été séparé remonte à l'intérieur de la chambre de chauffage 50 du chauffage d’appoint 5 et s'y accumule, provoquant une baisse du niveau du fluide technique qui y est présent et une translation conséquente et une descente du flotteur 63 ; ceci permet à l'obturateur 60, auquel le flotteur 63 est relié par l'intermédiaire de la tige de commande 62, de passer de ladite "configuration de fermeture" à ladite "configuration d'ouverture" de l'évent 64.

More precisely, according to a possible operating mode:

• in the absence of refrigerant leaks, or for modest quantities, the float 63 is normally located near the upper wall 65 of the ventilation valve 6 and the relative shutter 60 keeps closed or closes the vent 64, while the float 63 is located near the upper wall 65 of the ventilation valve 6,
• in the event of leaks, the refrigerant that has been separated rises inside the heating chamber 50 of the auxiliary heater 5 and accumulates there, causing a drop in the level of the technical fluid present there and a consequent translation and descent of the float 63; this allows the shutter 60, to which the float 63 is connected via the control rod 62, to pass from said "closing configuration" to said "opening configuration" of the vent 64.

Although not shown in the attached figures, nothing prevents said auxiliary heater 5 from also comprising, integrated and/or in fluid communication with its heating chamber 50, the aforementioned relief valve (not shown), otherwise positioned and installed in the conditioning circuit 3, preferably downstream of the main exchanger 21.

It should also be noted that in order to use the auxiliary heater 5 of the invention in "degassing" mode in complete safety, it is preferable that the heating element 53, inside the heating chamber 50, does not reach excessively high temperatures which could lead to the ignition and combustion of the refrigerant possibly present in the technical fluid and with which, in the event of leaks, it could come into direct contact.

In particular, it is desirable that the surface temperatures T _risc of said at least one heating element 53 are sufficiently lower than the auto-ignition temperature T _acc of the refrigerant used in the heat pump system 1.

For example, the maximum temperature T_riskwhich can be reached by said heating element 53 can be set and/or adjusted to remain below said auto-ignition temperature T_accrefrigerant of an appropriate safety threshold Δ_safety(T_risk< T_acc- Δ_safety).

• coopérer avec un thermostat adapté pour le déconnecter électriquement au cas où des conditions de surchauffe sont détectées, c'est-à-dire si T_risc> T_acc- Δ_safety, ou
• comporter un élément chauffant à coefficient de température positif (par exemple du type PTC) ou, plus généralement, un élément chauffant autorégulant 53 capable de maintenir sa température aussi constante que possible et de préférence en dessous de la température maximale T_riscadmise.

To this end, without any limiting intention, said at least one heating element 53 can therefore:

• cooperate with a suitable thermostat to electrically disconnect it in case overheating conditions are detected, i.e. if T_risk> T_acc- Δ_safety, Or
• have a heating element with a positive temperature coefficient (for example of the PTC type) or, more generally, a self-regulating heating element 53 capable of maintaining its temperature as constant as possible and preferably below the maximum temperature T _risc permitted.

It is clear that the solution with a self-regulating heating element 53 is preferable because it allows an intrinsic safety system and avoids the implementation of a thermostat appropriately dedicated to the control and/or regulation of the surface temperatures of the heating element.

In conclusion, the auxiliary heater 5 of the invention, also suitable for serving as a degassing device, makes it possible to achieve the desired objectives.

For example, as already mentioned, a component specifically and exclusively used for the interception and subsequent expulsion of any refrigerant leak is eliminated from the heat pump system 1, i.e. the traditional degasser or similar devices (i.e. component 4' of the is eliminated).

The combination of the technical fluid heating function and the refrigerant leakage interception function in a single device 5 makes it possible to reduce the total number of components of the heat pump system 1 and, consequently, the production and maintenance costs, as well as to optimize and compact the design, for example of the outdoor unit 10.

Furthermore, by avoiding installing a traditional degassing device in the heat pump system 1 of the invention, the function of which, as mentioned, is implemented by the auxiliary heater 5, no other localized pressure losses than those already normally and inevitably provided are introduced, which would excessively penalize the circulation of the technical fluid in the conditioning circuit 3. Consequently, the overall efficiency and safety of the heat pump system 1 are improved.

The integration of a degassing device and a backup heater in a single component also makes it possible to reduce the total number of hydraulic connections, fittings, seals or the like of the conditioning circuit 3, thereby effectively reducing the risk of leaks of technical fluids in the event of sealing defects. This can lead to a reduction in the management and maintenance costs of the heat pump system of the invention.

Finally, it should be noted that with the auxiliary heater 5 of the invention comprising at least one ventilation valve 6, it is possible to intercept and evacuate, according to methods and with results substantially similar to those provided for refrigerant leaks, any excess air in the pipes and/or terminals of the conditioning circuit 3, guaranteeing the regularity of the flow of technical fluid and the thermal capacity of the latter.

Finally, it should be noted that several variants of the heat pump system of the invention are possible for the person skilled in the art, without departing from the scope of novelty of the inventive idea, just as it is clear that in the practical implementation of the invention the various components described above can be replaced by technically equivalent elements. For example, nothing prevents integrating into the chamber 50 of the auxiliary heater 5 a shutter body (not shown) which, in the event of significant leaks of refrigerant and under the effect of the pressure of the latter being higher than that of the technical fluid, is able to close the outlet 52, preventing them from reaching the various terminals of the conditioning circuit 3 and promoting the separation of these from the same technical fluid.

Claims (14)

Heat pump system (1) comprising at least:

• a refrigeration circuit (2) in which a refrigerant circulates and operates on the primary side (24) of a main heat exchanger (21),
• a conditioning circuit (3) in which a technical fluid, used for the heating/cooling functions of premises and/or for the production of sanitary water, circulates and operates on the secondary side (25) of the main heat exchanger (21),

the heat exchange between said refrigerant and the technical fluid therefore takes place in said main exchanger (21),
said conditioning circuit (3):

• further comprising a circulation pump (30),
• comprising at least one auxiliary heater (5) for said technical fluid, provided with at least one heating chamber (50) and at least one heating element (53),

said auxiliary heater (5) further incorporating at least one ventilation valve (6) capable of expelling at least any possible refrigerant leaks before they diffuse into said conditioning circuit (3), the volume of the heating chamber (50) of said auxiliary heater (5) therefore acting as a degassing chamber (50) in which said technical fluid can propagate by reducing its speed and the driving force of any refrigerant leaks, thus promoting their separation

• being connected and cooperating with one or more terminals for heating/cooling said premises and/or for sanitary water,

characterized in thatsaid at least one heating element (53) of said emergency heater (5) functions as a separation device capable of interfering and further slowing down the flow of the technical fluid, thus improving the separation of possible refrigerant leaks. Heat pump system (1) according to claim 1, characterized in that said at least one heating element (53) comprises one or more electric heaters (53). Heat pump system (1) according to claim 2, characterized in that said at least one heating element (53) is a positive temperature coefficient heating element or a self-regulating heating element (53), said at least one heating element (53) maintaining its surface temperature (T _risc ) below the auto-ignition temperature (T _acc ) of the refrigerant. Heat pump system (1) according to claim 2, characterized in that said at least one heating element (53) cooperates with a thermostat adapted to electrically switch it off in the event of overheating, said at least one heating element (53) maintaining the surface temperature (T _risc ) below the auto-ignition temperature (T _acc ) of the refrigerant. Heat pump system (1) according to one or more of the preceding claims, characterized in that said ventilation valve (6) is installed at or near the upper wall (56) of said auxiliary heater (5) and in fluid communication with said heating chamber (50) thereof. Heat pump system (1) according to the preceding claim,characterized in thatsaid ventilation valve (6) is a valve comprising at least:

• a vent (64) for draining any possible refrigerant leaks,
• a shutter (60) capable of cooperating with the technical fluid which fills and/or passes through said heating chamber (50) of said auxiliary heater (5) and of opening said vent (64) depending on said possible leaks of refrigerant fluid in said technical fluid.

Heat pump system (1) according to the preceding claim,characterized in thatsaid shutter (60) is connected to a float (63) capable of floating in said technical fluid of the heating chamber (50), said float (63):

• being in proximity to said upper wall (65) of said ventilation valve (6) in the absence of refrigerant leaks, in this case said shutter (60) remains closed or closes said vent (64),
• translating and descending downwards when the refrigerant leaks have been separated from said technical fluid, in this case said shutter (60) passes from a "closing configuration" to an "opening configuration" of said vent (64).

Heat pump system (1) according to one or more of the preceding claims, characterized in that the ventilation valve (6) is of the type capable of intercepting and also evacuating excess air possibly present in the conditioning circuit (3). Heat pump system (1) according to one or more of the preceding claims, characterized in that said at least one auxiliary heater (5) comprises a relief valve, said relief valve being capable of opening for pressures of the technical fluid above a safety threshold. Heat pump system (1) according to one or more of the preceding claims, characterized in that said at least one auxiliary heater (5) is installed, relative to the operating direction (F) of the technical fluid, downstream of the main heat exchanger (21). Heat pump system (1) according to one or more of the preceding claims, characterized in that said refrigeration circuit (2) and, at least in part, said conditioning circuit (3) are housed in an external unit (10) of said heat pump system (1). Heat pump system (1) according to one of the preceding claims, characterized in that the refrigerant of the refrigeration circuit (2) is a refrigerant with low environmental impact. Auxiliary heater (5) for a heat pump system (1) according to one or more of claims 1 to 12, comprising at least one heating chamber (50) and at least one heating element (53) for a technical fluid suitable for heating/cooling premises and/or producing domestic water, characterized in that it further comprises a ventilation valve (6) capable of expelling at least any possible leaks of refrigerant fluid coming from the refrigeration circuit (2) of said heat pump system (1) before they diffuse into the relative conditioning circuit (3), the volume of said heating chamber (50) thus acting as a deaeration chamber (50) in which said technical fluid can propagate by reducing the speed and the driving force of these possible leaks of refrigerant fluid, promoting their separation. Use in a heat pump system (1), according to one or more of claims 1 to 12, of an auxiliary heater (5), according to at least claim 13, as a "degassing device" for intercepting and separating possible refrigerant leaks from a technical fluid.