Hydraulic module, heat pump comprising such a hydraulic module, and heating system comprising a heat pump with such a hydraulic module

Abstract

Hydraulic module, comprising a housing that is formed by at least a first and a second housing part that are welded together and enclose a first and a second chamber, wherein one or more than one internal structure within the housing define at least one of: - a baffle, arranged inside at least one of the first and the second chamber to define a flow path comprising at least a forward and a return flow path; and - a divider that divides a cavity into the first and the second chamber, wherein: - the one or more than one internal structure comprises one or more than one insert, which is an injection-moulded component distinct from the first and the second housing part; - the one or more than one insert is arranged between the first and the second housing part; and - the first housing part, the second housing part, and the one or more than one insert are welded together at their mating interfaces to form an integrated, monolithic part.

Description

[0001] Title: Hydraulic module, heat pump comprising such a hydraulic module, and heating system comprising a heat pump with such a hydraulic module

[0002] Descri ption:

[0003] The invention relates to a hydraulic module, comprising a housing that is formed by at least a first and a second housing part that are joined together in a watertight manner and enclose a first chamber and a second chamber.

[0004] The invention further relates to heat pump comprising such a hydraulic module, and a heating system comprising a heat pump with such a hydraulic module.

[0005] Hydraulic modules are key components in modern heating systems, such as domestic heat pumps. They are designed to manage the flow of hydraulic fluid between different circuits, for instance between a heat pump, a central heating circuit, and a domestic hot water system. A hydraulic module is a module that is designed to guide one or more than one flow of a hydraulic fluid, and may serve different purposes. For example, a hydraulic module may serve as a module that replaces a variety of conduits by integrating these conduits in one module, thereby allowing for a compact module that is moreover easy to install. Also, the hydraulic module may provide an internal flow connection between one or more conduit of the variety of conduits, and thereby form an open manifold. Especially the combination of providing a variety of conduits and provided one or more than one internal flow connection between conduits of said variety of conduits allows for a hydraulic module that may be compact and provide a high level of integration of different functionalities. Such hydraulic modules are for example very useful to be integrated in domestic heat pumps, where overall dimensioning of the heat pump, ease of installation, and suitability for mass production, are a key considerations.

[0006] In the prior art, two main design philosophies have emerged to address these competing demands.

[0007] European patent application EP 2 312 224 A2, which is considered the closest prior art for the present invention, is an exemplary embodiment of a first approach, that focuses on achieving the highest possible level of functional integration. In EP 2 312 224 A1, the hydraulic module is formed from two complex,injection-moulded housing halves which are permanently welded together to create a single, monolithic body. Complex, three-dimensional fluid flow paths are formed as integral features within the moulding of the housing halves themselves. This monolithic, welded construction is highly reliable as it minimizes the number of separate components and potential leak paths. However, this approach presents significant challenges in manufacturing. The moulds required to create such complex integral features are extremely expensive and time-consuming to produce. Furthermore, the design is inherently inflexible. After all, any modification to the internal flow path requires a complete and costly redesign of the main housing moulds.

[0008] Canadian patent application CA 2 809 865 A1 is an exemplary embodiment of a second, alternative approach, that prioritizes manufacturing simplicity and modularity. In CA 2 809 865 A1, the hydraulic module is constructed from simpler housing halves that are mechanically fastened together, for example with bolts, and sealed with a gasket. Internal flow control is achieved using simple, separate components. For instance, CA 2 809865 A1 discloses using a separate, flat plate as a divider that is placed between the housing halves to separate an inlet from an outlet. While this modular, assembly-focused approach simplifies manufacturing and allows for easier changes, it is structurally limited. It is generally only suitable for creating simple, linear flow paths and cannot achieve the high degree of functional complexity and compact integration seen in the first approach. Moreover, the reliance on mechanical fasteners and gaskets introduces additional components and potential failure points compared to a welded, monolithic body.

[0009] International patent application WO 2024 / 188860 A1 and European patent EP 3816521 B1 are acknowledged as further prior art.

[0010] As is clear from the two above-mentioned approaches, the prior art presents a skilled person with a technical trade-off: choose a highly integrated but inflexible and expensive monolithic design, like the closest prior art EP 2312224 A2, or choose a modular but functionally simple and potentially less reliable mechanically-assembled design, as presented in CA 2809865 A1.

[0011] There is an ongoing a need in the art for a hydraulic module that resolves this conflict.An objective of the present invention is to provide a hydraulic module, that is improved relative to the prior art and wherein at least one of the above stated problems is obviated or alleviated.

[0012] Said objective is achieved with the hydraulic module, comprising a housing that is formed by at least a first and a second housing part that are welded together in a watertight manner and enclose a first chamber and a second chamber, according to claim 1, wherein one or more than one internal structure within the housing define at least one of:

[0013] - a baffle, that is arranged inside at least one of the first chamber and the second chamber to define a flow path in said chamber that comprises at least a forward flow path and a return flow path that extend opposite relative to each other in a longitudinal direction of the at least one of the first chamber and the second chamber; and

[0014] - a divider that divides a cavity into the first chamber and the second chamber, and wherein:

[0015] - the one or more than one internal structure defining at least one of the baffle and the divider comprises one or more than one insert, which is an injection-moulded component distinct from the first and the second housing part;

[0016] - the one or more than one insert is arranged between the first and the second housing part; and

[0017] - the first housing part, the second housing part, and the one or more than one insert are welded together at their mating interfaces to form an integrated, monolithic part.

[0018] The present invention provides a hydraulic module with a novel construction that achieves both high functional complexity and manufacturing flexibility. The hydraulic module comprises a housing formed from at least a first and a second housing part. The key inventive concept resides in the use of one or more than one insert, which is a separate, injection-moulded component that is distinct from the housing parts. This one or more than one insert is arranged between the housing parts and defines the complex internal geometry of the module, such as baffles for creating specific flow paths and / or dividers for separating chambers. Subsequently, the first housing part, the second housing part, and the one or more than one insertare welded together at their mating interfaces. This process results in a single, integrated, and monolithic part that is hermetically sealed.

[0019] This construction provides significant advantages. By defining the complex internal flow paths using the separate one or more than insert, the main housing parts can be designed with a much simpler geometry. This drastically reduces the complexity and cost of the primary injection moulds. Furthermore, manufacturing flexibility is greatly enhanced, as modifications to the internal hydraulic layout can be achieved by simply redesigning the relatively small and inexpensive mould for the one or more than one insert, while the moulds for the larger housing parts can remain unchanged.

[0020] At the same time, because the housing parts and the one or more than one insert are permanently welded together, the final product is a structurally robust, monolithic body. This achieves the high reliability and pressure resistance of a fully integrated design, without the need for mechanical fasteners or gaskets that can be potential points of failure. The invention thus combines the manufacturing benefits of a modular approach with the performance and reliability benefits of a monolithic construction.

[0021] The use of one or more than one insert allows the hydraulic module to have a relatively complex internal routing of fluid flows, while still being easy to manufacture, even in mass production. More in particular, the first and the second housing parts, that are joined together, may form one or more than one cavity. For example, the insert may define a divider that divides a cavity into the first chamber and the second chamber. Alternatively, or additionally, the insert may also define a baffle, that is arranged inside at least one of the first chamber and the second chamber to define a desired flow path in said chamber. This flow path comprises at least a forward flow path and a return flow path that extend opposite relative to each other in a longitudinal direction of the at least one of the first chamber and the second chamber. The highest level of function integration may be obtained when the insert defines both such a divider and such a baffle at once.

[0022] Although different manufacturing methods for producing the first housing part, the second housing part and the insert, may be envisaged, including additive manufacturing of at least one of these parts, it is remarked that assembling the hydraulic module as proposed according to the present invention, allows the individualparts to be designed such that they may also be produced by injection moulding. In this way, the hydraulic module may be made out of parts that are suitable for mass production, while the hydraulic module - once the injection moulded parts are assembled - may form a hydraulic module with integrated flow paths that - as a whole - would not be suitable to be manufactured via injection moulding. The use of an insert thus allows a high level of function integration and complexity to be obtained in a module that is still suitable for mass production. This is especially relevant if such a hydraulic module is to be used in combination with a domestic heat pump.

[0023] According to a preferred embodiment of the hydraulic module:

[0024] - the first chamber comprises a main inlet and a secondary outlet;

[0025] - the second chamber comprises a secondary inlet and a main outlet;

[0026] - the main inlet is configured to receive a central heating return flow;

[0027] - the secondary outlet is configured to output a to be pre-heated flow towards a main heating device, preferably a heat pump;

[0028] - the secondary inlet is configured to receive the pre-heated flow back from the main heating device;

[0029] - the main outlet is configured to output a central heating forward flow; and - the second chamber is configured to, during use, allow the pre-heated flow that is received back from the main heating device to be heated further to a desired pre-determined temperature with an auxiliary heating device.

[0030] The hydraulic module with the first and second chamber, and the respective inlets and outlets, provides a compact and highly integrated hydraulic module that is especially suitable to be applied in combination with a domestic heat pump as a main heating device. The second chamber allows a pre-heated flow, that is received back from the main heating device to be heated further with an auxiliary heating device, such as an electric heater that is arranged inside the hydraulic module, or an auxiliary heating device that is arranged outside the hydraulic module. Such an external auxiliary heating device may comprise one of a gas boiler, a further heat pump, an instantaneous water heater and a wood stove.

[0031] According to a further preferred embodiment, the auxiliary heating device comprises an electric heater that is arranged inside the second chamber and that is configured to heat the pre-heated flow inside the second chamber to the desired pre-determined temperature. In this way, a heat pump may act as a main heatingdevice, and in cases wherein the heating capacity of the heat pump is insufficient, the electric heater that is arranged inside the second chamber can be used to increase the temperature of the pre-heated flow that is received from the heat pump.

[0032] According to a further preferred embodiment, the auxiliary heating device, that is configured to heat the pre-heated flow to the desired pre-determined temperature, is arranged outside the second chamber of the hydraulic module, and the second chamber comprises:

[0033] - a further outlet that is configured to output the pre-heated flow towards the auxiliary heating device for further heating thereof; and

[0034] - a further inlet that is configured to receive the heated flow back from the auxiliary heating device.

[0035] For extreme situations, or in order to obtain a very versatile heating system, it may be envisaged that the auxiliary heating device comprises both an electric heater that is arranged inside the second chamber of the hydraulic module, and an auxiliary heating device, such as a gas boiler, a further heat pump, an instantaneous water heater and a wood stove, that is arranged outside the second chamber of the hydraulic module.

[0036] The invention further relates to a heat pump, comprising a hydraulic module according to the invention, wherein:

[0037] - the main inlet of the hydraulic module is configured to be connected to a central heating return flow;

[0038] - the main outlet of the hydraulic module is configured to be connected to a central heating forward flow;

[0039] - the secondary outlet of the hydraulic module is connected to an inlet of the heat pump; and

[0040] - the secondary inlet of the hydraulic module is connected to an outlet of the heat pump.

[0041] The invention furthermore relates to a heating system, comprising: - a heat pump according to the invention; and

[0042] - a central heating circuit that is in flow connection with the main inlet and the main outlet of the hydraulic module.

[0043] Preferred embodiments are the subject of the dependent claims.The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, and in particular the aspects and features described in the attached dependent claims, may be an invention in its own right that is related to a different problem relative to the prior art.

[0044] In the following description preferred embodiments of the present invention are further elucidated with reference to the drawing, in which:

[0045] Figure 1 is a schematic view of a heating system comprising a heat pump with a hydraulic module according to the invention;

[0046] Figure 2A is a schematic top view of the first chamber of the hydraulic module;

[0047] Figure 2B is a schematic side view of the first chamber of the hydraulic module;

[0048] Figure 3A is a schematic top view of the second chamber of the hydraulic module in a first heating mode, wherein an electric heater is used for auxiliary heating;

[0049] Figure 3B is a schematic side view of the second chamber of the hydraulic module in the first heating mode;

[0050] Figure 3C is a schematic top view of the second chamber of the hydraulic module in a second heating mode, wherein an external heating device is used for auxiliary heating, as an alternative to, or supplementary to, the electric heater of the first heating mode;

[0051] Figure 3D is a schematic side view of the second chamber of the hydraulic module in the second heating mode;

[0052] Figure 4 is an exploded perspective view of the hydraulic module according to the invention;

[0053] Figure 5 is a perspective view of the hydraulic module of Figure 4 from above;

[0054] Figure 6 is a perspective view of the hydraulic module of Figure 4 from below;

[0055] Figure 7 is a top view of the hydraulic module;

[0056] Figure 8 is a cross sectional side view of the hydraulic module in section plane B-B through the first chamber;Figure 9 is a cross sectional side view of the hydraulic module in section plane C-C through the second chamber;

[0057] Figure 10 is a side view of the hydraulic module;

[0058] Figure 11 is a cross sectional top view of the hydraulic module in section plane A-A; and

[0059] Figure 12 is a perspective view of the second housing part from below. The heating system 1 of Figure 1 comprises a heat pump 5 and a hydraulic module 2. Although any type of heat pump 5 may be used, the exemplary embodiment comprises a domestic indoor exhaust air heat pump 6 that is configured to extract heat from exhaust air of an indoor ventilation system. Exhaust air of an indoor ventilation system, hereafter also referred to as “exhaust air", may form a very interesting heat source for a heat pump, because such exhaust air has a relatively high energy density, and would otherwise by expelled from the building as waste. In most countries, legislation requires ventilation of buildings, such as residential buildings and office spaces. Using an exhaust air heat pump allows at least a part of the thermal energy to be recovered, before it is allowed to leave the building. In this way, energy is recovered that would otherwise be wasted via the obligatory ventilation system. However, because such an indoor exhaust air heat pump 6 is arranged inside a building, the dimensioning of the heat pump is a key consideration. Although not essential for the functionality, the desire to have a compact overall design led to choice for the shown embodiment to integrate the hydraulic module 2 inside the casing 11 of the heat pump 5.

[0060] The heat pump 5 comprises an exhaust air inlet 5-1 and an exhaust air outlet 5-2. Using a fan 6, a flow E of exhaust air is forced over a primary heat exchanger 7, where heat is extracted from the exhaust air. The compressor 8 causes a flow to a secondary heat exchanger 9, where the heat may be transferred to an auxiliary heating circuit 10, that will be explained in more detail below.

[0061] The hydraulic module 2 comprises a housing 12 that is formed by at least a first housing part 36 and a second housing part 37 that are joined together in a watertight manner and enclose a first chamber 3 and a second chamber 4. According to the invention, the hydraulic module 2 comprises an insert 18 that is arranged between the first 36 and the second housing part 37. The insert 18 defines at least one of:- a baffle 19, that is arranged inside at least one of the first chamber 3 and the second chamber 4 to define a desired flow path in said chamber 3, 4; and

[0062] - a divider 20 that divides a cavity 21 into the first chamber 3 and the second chamber 4.

[0063] The exemplary embodiment shown in Figure 4 comprises two inserts 18, 18-1, 18-2 in order to elucidate the functionality of the baffle 19 and the divider 20 independently of each other. It is however explicitly mentioned that the insert 18-1 and the insert 18-2 can also be integrated to form a single insert 18.

[0064] In the shown embodiment, insert 18, 18-2 defines a divider 20 that divides the cavity 21 into two separate chambers 3, 4. It is however also conceivable that the housing parts 36, 37 are designed such that they already define two separate chambers 3, 4, without the need for an insert 18, 18-2.

[0065] The insert 18, 18-1 of the shown embodiment defines a baffle 19, that is arranged inside the first chamber 3 to define a desired flow path in said first chamber 3. The schematic top view of Figure 2A and the schematic side view of Figure 2B show the first chamber 3 and the flow path of fluid from a main inlet 3-1 towards a secondary outlet 3-2. Although the first chamber 3 and the second chamber 4 will be discussed in more detail below, it is clear from the flow path shown in Figures 2A, 2B that it would not be possible to make the hydraulic module 2 out of two injection moulded housing parts 36, 37. However, by using one or more than one insert 18, 18-1, 18-2, it is possible to allow the hydraulic module 2 to have a relatively complex internal routing of fluid flows, while still being easy to manufacture, even in mass production, especially via (but not limited to) injection moulding. The use of one or more than one insert 18, 18-1, 18-2 thus allows a high level of function integration and complexity to be obtained in a hydraulic module 2 that is still suitable for mass production. This is especially relevant if such a hydraulic module 2 is to be used in combination with a domestic heat pump 5.

[0066] As can be seen in Figures 2A, 2B, 8 and 11, the first chamber 3 is an elongate chamber having a longitudinal direction L3 (Figure 2A), and the insert 8, 8-1 defines the baffle 19 that extends in said longitudinal direction inside said first chamber 3 till a longitudinal offset 27 from an inner wall 28 of said chamber 3, to thereby define a forward flow path F3-F and a return flow path F3-R that extend opposite relative to each other in said longitudinal direction. The forward flow path F3-F and the returnflow path F3-R are directed opposite to each other. Their length, including the 180° bend around the edge of the baffle 19 that reverses the flow, allow the flow to become a laminar flow. The hydraulic module 2 further comprises a flow sensor 29 that is arranged in the return flow path F3-R of the first chamber 3. Because of the laminar flow, the accuracy of the flow measured by the flow sensor 29 is improved.

[0067] The first housing part 36, the second housing part 37 and the one or more than one insert 18, 18-1, 18-2 are preferably welded together at their interfaces to form an integrated part. In this way the different parts are securely bonded, guaranteeing a watertight bond. This welding process may be done by e.g. friction welding, vibration welding, ultrasonic welding, or laser welding, may be used to weld the parts together.

[0068] With reference to Figure 1, the heating system 1, and in particular the hydraulic module 2 thereof, are now explained in more detail.

[0069] The first chamber 3 of the hydraulic module 2 comprises a main inlet 3-1 and a secondary outlet 3-2. The second chamber 4 of the hydraulic module 2 comprises a secondary inlet 4-1 and a main outlet 4-2. The main inlet 3-1 of the first chamber 3 is configured to receive a central heating return flow CH-R, that is pumped by a pump 17. The secondary outlet 3-2 of the first chamber 3 is configured to output a to be pre-heated flow towards a main heating device 13. In the shown embodiment, the heat pump 5 defines the main heating device 13. The secondary inlet 4-1 of the second chamber 4 is configured to receive the pre-heated flow back from the main heating device 13, i.e. heat pump 5. The main outlet 4-2 of the second chamber 4 is configured to output a central heating forward flow CH-F, and the second chamber 4 is configured to, during use, allow the pre-heated flow that is received back from the main heating device 13 to be heated further to a desired pre-determined temperature with an auxiliary heating device 14.

[0070] As shown in Figure 1, the main inlet 3-1 of the hydraulic module 2 is configured to be connected to a central heating return flow CH-R, the main outlet 4-2 of the hydraulic module 2 is configured to be connected to a central heating forward flow CH-F, in order to provide heat to a central heating system 15. The central heating system 15 comprises one or more than one radiator 16 and a pump 17. Pump 17 causes a flow through the central heating circuit 18 that is in flow connection with the main inlet 3-1 and the main outlet 4-2 of the hydraulic module 2. In the shownembodiment, pump 17 is connected to the hydraulic module 2 and positioned directly downstream of the main inlet 3-1. For illustrative simplicity, the pump 17 is shown upstream of the hydraulic module 2 in the schematic representation of Figure 1, which could also be a working alternative. A pressure sensor 45 is configured to measure a pressure inside the first chamber 3.

[0071] The secondary outlet 3-2 of the hydraulic module 2 is connected to an inlet 5-3 of the heat pump 5, and the secondary inlet 4-1 of the hydraulic module 2 is connected to an outlet 5-4 of the heat pump 5.

[0072] As mentioned above, the second chamber 4 of the hydraulic module 2 is configured to, during use, allow the pre-heated flow that is received back from the main heating device 13 to be heated further to a desired pre-determined temperature with an auxiliary heating device 14. Thus, if the main heating device 13 is an indoor exhaust air heat pump 5, and the exhaust air of the indoor ventilation system alone is insufficient to meet the heating demand, further heating may be obtained with an auxiliary heating device 14. Such an auxiliary heating device 14 may be an electric heater 21 that is arranged inside the hydraulic module 2, and / or an auxiliary heating device 26 that is arranged outside the hydraulic module 2. Both version of auxiliary heating devices 14, 21, 26 are now discussed in more detail.

[0073] According to a first heating mode, the auxiliary heating device 14 may comprise an electric heater 21 that is arranged inside the second chamber 4 and that is configured to heat the pre-heated flow inside the second chamber 4 to the desired pre-determined temperature. The electric heater 21 is shown in detail in Figure 4, and comprises a heating coil 22 that extends on both sides of a baffle plate 23. The baffle plate 23 creates forward flow F4-F and return flow F4-R inside the second chamber 4, and thereby guarantees that the fluid flows along substantially the whole length of the heating coil 22. This allows the heating coil 22 of the electric heater 21 to further heat the fluid that was pre-heated by the main heating device 13, such as the heat pump 5.

[0074] As can be seen in Figures 3A, 3B, 3C, 3D, 9 and 11 , the second chamber 4 is elongate and extends in a longitudinal direction L4 (Figures 3A and 3C). The electric heater 21 is elongate and extends in the longitudinal direction L4 inside the second chamber 4. In the shown embodiment, the first chamber 3 and the second chamber 4 extend parallel to each other, and their longitudinal directions L3 and L4 are parallel to each other.The electric heater 21 extends in the longitudinal direction L4 inside the second chamber 4 till a longitudinal offset 30 from an inner wall 31 of said second chamber 4 and comprises a further baffle 23 to thereby define a forward flow path F4-F and a return flow path F4-R that extend opposite relative to each other in said longitudinal direction L4 in said second chamber 4.

[0075] The hydraulic module 2 further comprises a temperature sensor 32 that is arranged near the main outlet 4-2, and more preferably in the return flow path F4-R of the second chamber 4.

[0076] Figure 11 shows that the hydraulic module 2 comprises one or more than one flow guide 33 to promote a turbulent flow in the return flow path F4-F in the second chamber 4. A turbulent flow mixes to promote a uniform temperature distribution, and thereby increases the measurement accuracy of the temperature sensor 32. In the shown embodiment, the one or more than one flow guide 33 is arranged on an inner wall 34 of the return flow path F4-R.

[0077] According to a second heating mode, that is shown in Figures 3C and 3D, the auxiliary heating device 14, that is configured to heat the pre-heated flow to the desired pre-determined temperature, is arranged outside the second chamber 4 of the hydraulic module 2, and the second chamber 4 comprises:

[0078] - a further outlet 4-4 that is configured to output the pre-heated flow towards the auxiliary heating device 14 for further heating thereof; and

[0079] - a further inlet 4-3 that is configured to receive the heated flow back from the auxiliary heating device 14.

[0080] The second chamber 4 now defines an open manifold 24. Such an open manifold 24 allows the pre-heated fluid inside the second chamber 4 to be drawn out of the second chamber 4 of the hydraulic module 2 by an independent pump 25 of the auxiliary heating device 14, 26. This auxiliary heating device 14, 26 may comprise one of a gas boiler, a further heat pump, an instantaneous water heater and a wood stove. Once heated further by the externally arranged auxiliary heating device 14, 26, the return flow enters the second chamber 4 at the further inlet 4-3, and the open manifold allows for a mixing of the pre-heated fluid inside the second chamber 4, and the heated return flow.

[0081] It is emphasized that the hydraulic module 2 may be operated in the first heating mode that applies the electric heater 21 as auxiliary heating device 14 (Figures3A and 3B), in the second heating mode that applies an external heating device 26 as auxiliary heating device (Figures 3C and 3D), or a combination thereof. To elucidate that the combination of the first heating mode and the second heating mode is also possible, the embodiment of Figures 3C and 3D also comprises the electric heater 21.

[0082] If the hydraulic module 2 is to be run in the second heating mode only, it is possible that the electric heater 21 is absent from the second chamber 4. In this case, the second chamber 4 may comprise an opening 35 that may be closed off with a (not shown) removable cover that allows the electric heater 21 to be arranged in retrofit. Figure 4 shows how the electric heater 21 is arranged through the opening 35. This allows a user to use a heat pump 5 via the hydraulic module 2 with a conventional gas boiler at this stage, while having the flexibility to switch to an electric alternative with the electric heater 21 in the future.

[0083] Figures 9 and 12 show that the second chamber 4 comprises, in an orientation during use, an upward extending space 38 that is configured to collect air A that is present in the hydraulic module 2. As long as there is a flow in the second chamber 4, any air bubbles are transported to near the main outlet 4-2. As air rises inside a liquid flow, the air A is collected in the upward extending space 38. As long as the flow in the second chamber 4 continuous, the air A remains trapped inside said space 38. However, as soon as the flow stops, the air A may pass via the arrow B through a bypass channel 39 towards the secondary inlet 4-1, that may now serve to allow the air A to escape out of the hydraulic module 2. This bypass channel 39 that is configured to allow the air A to escape from the upward extending space 38 to the secondary inlet 4-1 of the second chamber 4 is shown in Figure 12, that shows a perspective view of the second housing part 37 from below. Because the upward extending space 38 is arranged near the temperature sensor 32 and extends to a higher level than the temperature sensor 32, it is prevented that any accumulated air A prevents the temperature sensor 32 from measuring the temperature of the water inside the second chamber 4 of the hydraulic module 2.

[0084] In the exemplary embodiment shown in Figure 6, the main inlet 3-1, the main outlet 4-2, the further inlet 4-3 and the further outlet 4-4 are arranged next to each other.

[0085] According to a preferred embodiment, at least two, and preferably all, of the main inlet 3-1, the main outlet 4-2, the further inlet 4-3 and the further outlet 4-4share a common locking device 40. In the shown embodiment, the locking device 40 comprises a slider 41 that is slidable (in the direction indicated with arrow S) between an unlocked state, allowing conduits to be connected to the inlets 3-1, 4-3 and outlets 4-2, 4-4, and a locked state, wherein the conduits are clamped around the respective inlets 3-1, 4-3 and outlets 4-2, 4-4.

[0086] The slider 41 comprises an arm 42 that extends outward relative to the hydraulic module 2. This arm may serve to slide the slider 41, but may also provide a safety measure. In a preferred embodiment, a casing 11 of the heat pump 5 can only be closed when the slider 41 is in the locked state.

[0087] Likewise, the secondary outlet 3-2 and the secondary inlet 4-1 may also share a common locking device 42, that is embodied as a slider 43 with an arm 44. It is conceivable that the hydraulic module 2 may only fit inside the casing when the slider 43 is in the locked state, thereby guaranteeing a secure clamping of the conduits that connect the hydraulic module with the heat pump 5.

[0088] The above described embodiment is intended only to illustrate the invention and not to limit in any way the scope of the invention. Accordingly, it should be understood that where features mentioned in the appended claims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting on the scope of the claims. The scope of protection is defined solely by the following claims.

Claims

CLAIMS1. Hydraulic module (2), comprising a housing (12) that is formed by at least a first housing part (36) and a second housing part (37) that are welded together in a watertight manner and enclose a first chamber (3) and a second chamber (4), wherein one or more than one internal structure within the housing define at least one of:- a baffle (19), that is arranged inside at least one of the first chamber (3) and the second chamber (4) to define a flow path in said chamber that comprises at least a forward flow path (F3-F) and a return flow path (F3-R) that extend opposite relative to each other in a longitudinal direction of the at least one of the first chamber (3) and the second chamber (4); and- a divider (20) that divides a cavity (21) into the first chamber (3) and the second chamber (4), characterized in that:- the one or more than one internal structure defining at least one of the baffle (19) and the divider (20) comprises one or more than one insert (18), which is an injection-moulded component distinct from the first (36) and the second housing part (37);- the one or more than one insert (18) is arranged between the first (36) and the second housing part (37); and- the first housing part (36), the second housing part (37), and the one or more than one insert (18) are welded together at their mating interfaces to form an integrated, monolithic part.

2. Hydraulic module according to claim 1, wherein:- the first chamber comprises a main inlet and a secondary outlet;- the second chamber comprises a secondary inlet and a main outlet;- the main inlet is configured to receive a central heating return flow;- the secondary outlet is configured to output a to be pre-heated flow towards a main heating device, preferably a heat pump;- the secondary inlet is configured to receive the pre-heated flow back from the main heating device;- the main outlet is configured to output a central heating forward flow; and- the second chamber is configured to, during use, allow the pre-heated flow that is received back from the main heating device to be heated further to a desired pre-determined temperature with an auxiliary heating device.

3. Hydraulic module according to claim 2, wherein the auxiliary heating device comprises an electric heater that is arranged inside the second chamber and that is configured to heat the pre-heated flow inside the second chamber to the desired predetermined temperature.

4. Hydraulic module according to claim 2 or 3, wherein the auxiliary heating device, that is configured to heat the pre-heated flow to the desired pre-determined temperature, is arranged outside the second chamber of the hydraulic module, and the second chamber comprises:- a further outlet that is configured to output the pre-heated flow towards the auxiliary heating device for further heating thereof; and- a further inlet that is configured to receive the heated flow back from the auxiliary heating device.

5. Hydraulic module according to claim 4, wherein the second chamber defines an open manifold.

6. Hydraulic module according to claim 4 or 5, wherein the auxiliary heating device comprises one of a gas boiler, a further heat pump, an instantaneous water heater and a wood stove.

7. Hydraulic module according to any of the foregoing claims, wherein the first chamber is an elongate chamber having a longitudinal direction, and the one or more than one insert defines the baffle that extends in said longitudinal direction inside said first chamber till a longitudinal offset from an inner wall of said chamber.

8. Hydraulic module according to claim 7, wherein the hydraulic module further comprises a flow sensor that is arranged in the return flow path of the first chamber.

179. Hydraulic module according to any of claims 3-8, wherein:- the second chamber is elongate and extends in a longitudinal direction; and - the electric heater is elongate and extends in the longitudinal direction inside the second chamber.

10. Hydraulic module according to claim 9, wherein the electric heater extends in the longitudinal direction inside the second chamber till a longitudinal offset from an inner wall of said second chamber and comprises a further baffle to thereby define a forward flow path and a return flow path that extend opposite relative to each other in said longitudinal direction in said second chamber.

11. Hydraulic module according to any of claims 2-10, wherein the hydraulic module further comprises a temperature sensor that is arranged near the main outlet.

12. Hydraulic module according to claims 10 and 11, wherein the temperature sensor is arranged in the return flow path of the second chamber.

13. Hydraulic module according to any of the foregoing claims, comprising one or more than one flow guide to promote a turbulent flow in the return flow path.

14. Hydraulic module according to any of the foregoing claims, wherein the second chamber comprises, in an orientation during use, an upward extending space that is configured to collect air that is present in the hydraulic module.

15. Hydraulic module according to any of the foregoing claims 11-14, wherein the upward extending space is arranged near the temperature sensor and extends to a higher level than the temperature sensor.

16. Hydraulic module according to claim 14 or 15, further comprising a bypass channel that is configured to allow air to escape from the upward extending space to the secondary inlet of the second chamber.1817. Hydraulic module according to any of the foregoing claims, wherein the first chamber and the second chamber extend parallel to each other.

18. Hydraulic module according to any of the foregoing claims 3-17, wherein the second chamber comprises an opening with a removable cover that allows the electric heater to be arranged in retrofit.

19. Hydraulic module according to any of the foregoing claims 4-18, wherein the main inlet, the main outlet, the further inlet and the further outlet are arranged next to each other.

20. Hydraulic module according to claim 19, wherein at least two, and preferably all, of the main inlet, the main outlet, the further inlet and the further outlet share a common locking device.

21. Hydraulic module according to claim 20, wherein the locking device comprises a slider that is slidable between an unlocked state, allowing conduits to be connected to the inlets and outlets, and a locked state, wherein the conduits are clamped around the respective inlets and outlets.

22. Hydraulic module according to claim 21, wherein the slider comprises an arm that extends outward relative to the hydraulic module.

23. Heat pump, comprising a hydraulic module according to any of the foregoing claims, wherein:- the main inlet of the hydraulic module is configured to be connected to a central heating return flow;- the main outlet of the hydraulic module is configured to be connected to a central heating forward flow;- the secondary outlet of the hydraulic module is connected to an inlet of the heat pump; and- the secondary inlet of the hydraulic module is connected to an outlet of the heat pump.

24. Heat pump according to claim 23, wherein the heat pump comprises: - a hydraulic module according to any of claims 20-22; and- a casing that can only be closed when the slider is in the locked state.

25. Heating system, comprising:- a heat pump according to claim 23 or 24; and- a central heating circuit that is in flow connection with the main inlet and the main outlet of the hydraulic module.

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