Heating system and interface unit

Abstract

A heating system comprises a heat pump (10) which is coupled for heat-exchanging contact to a heat delivery installation (60). The heat pump is connected via an interface unit (300) to the heat generating device (60). The interface unit comprises a unit housing with primary connections (31, 32) for connection of respectively the feed (10A) and return (10R) conduit of the heat pump (10) and secondary connections (37, 38) for connection of respectively a feed (60A) and return (60R) conduit of the heat generating device (60), and additionally an electronic unit control (E3) which is coupled for exchange of control information to the control device (E1) of the heat pump. The connections (31, 32, 37, 38) form part of a hydraulic installation (50) inside the unit housing (30) which comprises one or more components from a group of piping, pumps, expansion tanks, buffer tanks and accessories such as electronic control valves, electronic sensors, filters, separators and fittings.

Description

[0001] The present invention relates to a heating system, comprising a heat generating device with an electronic control which is coupled for heat-exchanging contact to a heat delivery installation, comprising a heat pump with a control device and with a feed and return conduit for the heat-carrying medium, which heat-carrying medium provides for the heat-exchanging contact with the heat generating device, wherein the heat pump is coupled via a hydraulic installation of an interface unit to the heat generating device, which interface unit comprises a unit housing in which primary connections are provided for connection of respectively the feed and return conduit of the heat pump and wherein secondary connections are provided for connection of respectively a feed and return conduit of the heat generating device. The invention moreover relates to an interface unit for application in such a heating system.

[0002] A heating system of the type described in the preamble is applied on large scale for heating homes and other buildings. The heat generating device is usually formed here by a network of radiators or a system of floor heating conduits through which water with increased temperature is guided in order to generate heat to the surrounding area, whereby the space in question is heated. The heat delivery installation applied for this purpose usually comprises a central heating boiler fuelled with natural gas or oil, or a similar combustion device based on combustion of a solid fossil fuel such as coal, brown coal, wood (pellets) and the like. With a view to an energy transition to more durable energy management, demand has grown in recent years for a heat pump as part of the heat delivery installation, whether to serve as independent device for supplying heat or in a hybrid configuration with a traditional combustion device.

[0003] A heat pump displaces heat by means of work and can be applied to heat buildings. Said heat can be extracted from the outside air or from water, usually groundwater but for instance also surface water or process or installation water. In the first case reference is usually made to an air / water heat pump; in the latter case of a water / water heat pump. An advantage of a heat pump is an extremely high energy efficiency. Provided that it is correctly dimensioned and installed, a heat pump can supply considerably more heat than is consumed in energy to supply said work.

[0004] This energy is usually supplied by an electrically driven liquid pump whereby a heat-carrying fluid, usually referred to as coolant, is pumped around in a thermodynamic cycle of compression and evaporation, wherein heat is transferred via a heat exchanger to the heat generating device. The amount of heat that can be supplied in this manner depends on the technique used and the temperature difference to be overcome. In optimal situations the generated amount of heat can be up to five times more than the power consumed by the pump. Buildings can therefore be heated in particularly efficient and environmentally friendly manner with a suitable heat pump.

[0005] This however makes the thermodynamic process of a heat pump more complex than that of a conventional combustion boiler. Not only must the electric pump be matched correctly to the power to be generated by the heat pump, the hydraulic installation applied on the liquid side has also been found to be of crucial importance for achieving optimal energy efficiency. If conduit segments are dimensioned incorrectly here, or appendages and other components are applied incorrectly, a large part of the potential energy gain may be negated thereby. Given this complexity, it will therefore come as no surprise that many installed heat pumps function far from optimally and, in the worst case, consume more energy than they generate. In such cases, the traditional installer or plumber often lacked the necessary expertise.

[0006] In order to close this knowledge gap European patent application EP 3.705.786 describes an interface unit in which a hydraulic interface installation is accommodated. Via this unit a heat pump expanded with a fired central heating boiler can be coupled to a heating system without requiring a great deal of technical knowledge on the part of the installer. Instead, the interface unit provides for all the components necessary therefor, and the installer need merely connect the primary and secondary conduits.

[0007] A drawback of this known interface unit is that control takes place therein mainly on the basis of recorded water temperatures, such as those detected in the interface unit between the feed and outlet conduits. Hereby, the unit has in some cases a slow response to sudden changes in heat demand, and operation of the heat pump is also far from optimal under determined conditions. The operation of the known interface unit is also limited to relatively low powers on the liquid side.

[0008] The present invention therefore has for its object, among others, to provide a heating system which obviates this to at least significant extent.

[0009] For this purpose a heating system of the type described in the preamble has the feature according to the invention that the interface unit comprises an electronic unit control with an electronic connection which is coupled for exchange of control information to the control device of the heat pump and to the control of the heat generating device, that the heat pump is at least partially controlled by the unit control, and that the primary connections and the secondary connections form part of a hydraulic installation of the unit housing which is controlled by the unit control and which comprises one or more components from a group of piping, pumps, expansion tanks, buffer tanks and accessories such as electronic control valves, electronic sensors, filters, separators and fittings.

[0010] The hydraulic installation applied on the liquid side between the heat pump and the heat delivery installation is thus accommodated for the most part, if not wholly, in an interface unit to be applied as standard module and having a unit control which also takes over control of the heat pump at least partially. For this purpose the unit control is able to exchange control information, including control signals and commands, with the heat pump with the electronic connection provided for this purpose. This bidirectional coupling between the control of the heat pump and the unit control of the interface unit allows the unit control to intervene on that of the heat pump, for instance in order to respond to a change in heat demand observed by the unit control or in order to impose a seasonal operation thereto. In this respect the interface unit is for instance also suitable, if desired, for connection of a cooling circuit in summer, wherein the heat pump supplies cooling water thereto. In that case the dominant control of the unit control imposes the desired operation on the heat pump.

[0011] The components of the hydraulic installation accommodated in the interface unit are correctly assembled and mutually coupled beforehand, matched with the heat pump applied. The installer need therefore not concern him or herself therewith, and need merely connect the connections provided on the unit housing of the interface device for this purpose. No specialized knowledge is needed therefor. Thus making use of a wholly or at least largely standardized hydraulic installation greatly enhances, if not ensures, that the heat pump will produce an optimal efficiency.

[0012] A heating system is often accompanied by a provision for hot tap water, for instance for a kitchen or bathroom. In order to be able to provide for this as well, a particular embodiment of the heating system has the feature according to the invention that a tap water provision, particularly a boiler, is provided outside the interface unit, wherein the unit housing comprises connections for a hydraulic connection of a feed and return conduit of the tap water provision.

[0013] In the absence of heat demand by the heat generating device or in the event of insufficient heat demand, there is a chance that the heat pump is unable to lose its deliverable heat and switches itself off, and switches back on in the event of even a low heat demand. This so-called "knocking" results in a reduced efficiency of the heat pump and moreover in premature wear of the pump in particular. In order to prevent this, a buffer reservoir is therefore preferably provided on the liquid side, in which reservoir a surplus of heat can be stored at least temporarily.

[0014] Such a reservoir can be incorporated in the interface unit, but then may result therein in a higher weight than is ergonomically responsible. A preferred embodiment of the heating system therefore has the feature according to the invention that a buffer tank is provided outside the interface unit between the primary connections, wherein the unit housing comprises connections for a hydraulic connection of a feed and return conduit of the buffer tank. The buffer tank can thus be provided separately of the interface unit so as to distribute the overall weight thereof and so limit a bearing load for an installer.

[0015] For a correct and optimal operation of the heating system a balanced distribution of a primary circulation from the heat pump over the buffer tank and a secondary circulation through the heat generating device is important. With this in mind, a preferred embodiment of the heating system has the feature according to the invention that the primary circulation and the secondary circulation are hydraulically neutrally coupled to each other inside the interface unit.

[0016] In order to be able to monitor and optionally regulate, or even autonomously control, a correct mutual matching between said primary and secondary circulation a further preferred embodiment of the heating system has the feature according to the invention that the hydraulic installation comprises at least a pump which maintains between the primary connections a primary circulation over the buffer tank and between the secondary connections a secondary circulation over the heat generating device, wherein coupled to the unit control is a primary electronic flow sensor which is incorporated between the primary connections and from which an electronic signal can be received as a measure of the primary circulation, and wherein coupled to the unit control is a secondary electronic flow sensor which is incorporated between the secondary connections and from which an electronic signal can be received as a measure of the secondary circulation.

[0017] The unit control therefore has up-to-date information regarding the flow in the primary and secondary circulation, so that the unit control is able to correct on the basis thereof by means of controllable valves and / or control valves provided for this purpose in the hydraulic installation in that case, or can control on the basis thereof. If desired, the output signals of the two sensors can also be read manually in order to monitor the system.

[0018] In a particular embodiment the interface unit provides on the liquid side a standardized hydraulic connection between a commercially available heat pump and a heat generating device which is present. An electronic coupling which couples the hydraulic installation operatively to the control device of the heat pump is preferably also provided here. For this purpose a further preferred embodiment of the heating system has the feature according to the invention that the electronic connection is provided by an adapter unit inside the interface unit which connects the hydraulic installation electrically to the control device of the heat pump.

[0019] The interface unit preferably provides the heat pump, on the liquid side and electronically, with a complete system for coupling to the heat generating device, optionally expanded externally with a buffer reservoir and / or a provision for hot tap water. In this respect a heating system according to the invention is therefore characterized in that the hydraulic installation comprises inside the unit housing piping in which at least a pump, an expansion tank and various accessories such as electronic control valves, electronic sensors, filters, separators and fittings are incorporated, and more particularly in that the heat pump is coupled to the heat generating device only via the interface unit, and optionally a buffer tank provided externally of the interface unit. In the latter case the interface unit provides, besides mutually connecting piping, everything that is needed for coupling the heat pump in adequate and energetically optimal manner to the heat generating device, such as a network of radiators and / or floor heating pipes.

[0020] The heating system according to the invention is suitable for various types of heat pump. In this respect a particular embodiment of the heating system has the feature according to the invention that the heat pump comprises an air / water heat pump or a water / water heat pump.

[0021] In light of the foregoing, the invention also provides an interface unit for application in a heating system, comprising a unit housing and a hydraulic installation which is at least substantially enclosed by the unit housing and wherein primary connections are provided for connection of respectively the feed and return conduit of a heat pump, and wherein secondary connections are provided for connection of respectively a feed and return conduit of a heat generating device, and comprising a unit control with an electronic connection for coupling to the control device of the heat pump for the purpose of control information, wherein the hydraulic installation comprises inside the unit housing one or more components, controlled by the unit control, from a group of piping, pumps, expansion tanks, buffer tanks and accessories such as electronic control valves, electronic sensors, filters, separators and fittings.

[0022] The invention will be further elucidated hereinbelow with reference to an exemplary embodiment and an accompanying drawing. In the drawing: Figure 1is an exemplary embodiment of a heating system according to the invention; Figure 2is an exemplary embodiment of an interface unit with a hydraulic installation for use in the heating system of figure 1; and Figure 3is a rear view of the interface unit of figure 2.

[0023] It is otherwise noted here that the figures are purely schematic and not all drawn to (the same) scale. Some dimensions in particular may be exaggerated to greater or lesser extent for the sake of clarity. Corresponding parts are designated in the figures with the same reference numeral.

[0024] Figure 1 shows schematically a heating system according to the invention wherein use is made of a heat / air heat pump 10 as heat delivery device. The heat pump 10 is a commercially available device from a reputable brand, such as for instance ACOND, Domusa, Nube or Mitsubishi Electric. In this example use is made of model R290 from the pro-series from ACOND for use in a home 100 for heating, cooling and preparation of hot tap water.

[0025] Preparation of hot tap water is realized by means of an indirectly heated boiler 20 with a volume of for instance 150-300 litres. The system is further provided with a buffer tank 40. The whole also comprises a control E1 from heat pump 10 and a control system E6 of a heat generating device 60 of the home. A control screen on which the whole installation is visualized and can be controlled can be mounted centrally in home 100. At least a number of rooms of home 100 are deemed independent temperature zones, and for this purpose individual temperature sensors T1-T6 are placed therein for controlling the relevant zone on the basis thereof. These sensors T1-T6 are each coupled individually or via a joint bush to the control E6.

[0026] Energetically, the home is thermally optimally insulated in accordance with the latest standards and is heated by means of the heat generating device 60. This device 60 can comprise one or more radiators, but will usually be embodied at least partially, as it is here, as floor heating in the form of a hot water-carrying pipe system integrated into a floor of a space. The heat generating device 60 is coupled via an interface unit 30 to heat pump 10 for heat-exchanging contact via a feed conduit and return conduit 60A, 60R for hot water. A nominal hydraulic diameter of these conduits is DN32, and in this case a maximum heat pump power of heat pump 10 amounts to about 20 kW (dT=10K). In the given example the buffer reservoir 40 and the tap water provision 20 are provided externally of the unit 30, although the unit 30 comprises in addition thereto inside a joint unit housing 35 the total hydraulic installation 50 as shown schematically in figure 2 by way of example.

[0027] According to the present invention, the feed and discharge conduit 60A, 60R do not run directly to the heat pump but are coupled to the interface unit 30, which is provided for this purpose with connections 37, 38 intended therefor. The interface unit 30 accommodates a wholly or almost wholly hydraulic installation 35 which connects the heat generating device 60 hydraulically to the heat pump 10. The unit comprises an aluminium frame with steel plating as unit housing in the order of 600x500x1300 millimetres (width x depth x height).

[0028] Accommodated in the unit are all the necessary hydraulic and electronic components which connect the hydraulic installation 50 electrically to the control device E1 of the heat pump and to the remaining installation components E6 in a building in order to achieve a correct and optimally efficient heat pump installation, including particularly an electronic unit control E3 which controls and drives the whole. According to the invention, the unit control E3 of the unit is also coupled to the control E1 of heat pump 10 in order to exchange control information therewith, including any control commands being imposed on heat pump 10. The unit control E3 further serves as an interface between the control E1 of heat pump 10 and the control E6 of the home with the sensors T1-T6 coupled thereto.

[0029] Figure 2 shows a heat pump installation with a high-temperature air / air heat pump 10, an electric auxiliary heater 70, a tap water boiler 20, a central heating buffer 40, a low-temperature output group 60 and a high-temperature output group 60'. The low-temperature output group 60 feeds for instance a floor heating in the home, while the high-temperature outlet group 60' is intended for radiator heating.

[0030] Between the heat pump 10 and the heat generating device 60, 60' in home 100 lies a hydraulic installation 50 which, according to the invention, is accommodated wholly inside an independent interface unit 30. The interface unit is coupled by means of standard conduits to the heat pump 10, the boiler 20, the buffer tank 40 and the heat generating device 60, 60'. For this purpose standard hydraulic connections 31-38 are provided externally on the interface unit 30 for respective circulations of heated water or another suitable heat-carrying fluid. These connections are designated schematically at the appropriate position in the overview of figure 2 and are located on the rear side of unit 30, as shown in figure 3.

[0031] After installation of heat pump 10, boiler 20, interface unit 30 and buffer tank 40, the installer need merely connect the separate components 10, 20, 30, 40 of the system to interface unit 30 on the rear side in usual manner. This results in an extremely short installation time and error-free connection for the average installer in that the interface unit was in each case pre-matched with the specific type, make and model of heat pump 10, wherein it is for instance possible to envisage: A low-temperature air / water heat pump with boiler valve, buffer connections and mixed output group for floor heating or convectors; A high-temperature air / water heat pump with primary pump, boiler valve, electrical element, mixed output group for floor heating and mixed output group for radiators; A low-temperature water / water heat pump with passive cooling exchanger, boiler valve, buffer connections and mixed output group for floor heating or convectors; and / or A low-temperature water / water heat pump with active and passive cooling exchanger, four-pipe change-over output group for floor heating and four-pipe change-over output group for convectors.

[0032] In addition to the electronic unit control E3 with ports and electrical wiring, the hydraulic installation of figure 2 comprises inside interface unit 30 all the usual hydraulic components necessary for coupling the parts of the whole installation to each other, such as optionally flexible piping, a primary circulation pump P1, a set of secondary circulation pumps P2, P2', an 18-litre expansion tank 80 and accessories such as diverse electronic control valves, diverse temperature sensors Tn and pressure sensors Pn, a dirt filter / vent 91, a dirt separator with magnet 92, a boiler valve 93 (three-way) and diverse fittings. In addition, an electrical heating element 95 is incorporated in the installation in order to keep the whole frost-free at all times.

[0033] In order to enhance a correct balance between the circulation through the expansion tank 40 and the heat generating device 60, 60' a hydraulic neutral distribution bar 96, 96' is provided between the primary circulation and the secondary circulation inside the interface unit 30. The primary circulation and the secondary circulation each comprise a respective flow sensor Q1 and Q2, Q2', whereby these circulations can be measured and optionally be fine-adjusted, optionally manually.

[0034] A filling and draining provision is provided, and a drip tray 41 in which leakage water can be collected during maintenance and service is situated, at the bottom of unit 30. The unit can be placed level by means of a set of plastic adjusting feet 42, see figure 3. The unit is insulated vapour-tightly and is surrounded by a corrosion-resistant plating of preserved (powder-coated) steel, stainless steel, plastic or aluminium, which is mounted on an aluminium base frame.

[0035] Because the interface unit is a prefabricated product, installation on site is rapid and simple. This results in a much higher chance of installation being carried out correctly on the first try than when the installer must carry out the whole hydraulic installation by his or herself on site. All components are integrated in the unit: hydraulic, electronic and in respect of control engineering. This means that installers will spend less time on engineering and work preparation. As much preparation as possible has also been done in terms of electrical engineering. The whole heat pump installation can be finished in one operation without additional specialists being needed on site for this purpose.

[0036] The interface unit moreover enables installers to offer the heating system as standard kits. This makes the process from advice and sales to commissioning simpler and clearer; both for the installer and for the end user. With its modest dimensions the interface unit additionally enables a compact and flexible configuration of the heat pump in a home or commercial premises.

[0037] Although the invention has been further elucidated above with reference to only a single exemplary embodiment, it will be apparent that the invention is by no means limited thereto. On the contrary, many variations and embodiments are still possible within the scope of the invention for a person with ordinary skill in the art.

Claims

1. Heating system, comprising a heat generating device with an electronic control which is coupled for heat-exchanging contact to a heat delivery installation, comprising a heat pump with a control device and with a feed and return conduit for the heat-carrying medium, which heat-carrying medium provides for the heat-exchanging contact with the heat generating device, wherein the heat pump is coupled via a hydraulic installation of an interface unit to the heat generating device, which interface unit comprises a unit housing in which primary connections are provided for connection of respectively the feed and return conduit of the heat pump and wherein secondary connections are provided for connection of respectively a feed and return conduit of the heat generating device, characterized in that the interface unit comprises an electronic unit control with an electronic connection which is coupled for exchange of control information to the control device of the heat pump and to the control of the heat generating device, that the heat pump is at least partially controlled by the unit control, and that the primary connections and the secondary connections form part of a hydraulic installation of the unit housing which is controlled by the unit control and which comprises one or more components from a group of piping, pumps, expansion tanks, buffer tanks and accessories such as electronic control valves, electronic sensors, filters, separators and fittings.

2. Heating system according to claim 1, characterized in that a tap water provision, particularly a boiler, is provided outside the interface unit, wherein the unit housing comprises connections for a hydraulic connection of a feed and return conduit of the tap water provision.

3. Heating system according to claim 1 or 2, characterized in that a buffer tank is provided between the primary connections outside the interface unit, wherein the unit housing comprises connections for a hydraulic connection of a feed and return conduit of the buffer tank.

4. Heating system according to claim 3, characterized in that the primary circulation and the secondary circulation are hydraulically neutrally coupled to each other inside the interface unit.

5. Heating system according to claim 4, characterized in that the hydraulic installation comprises at least a pump which maintains between the primary connections a primary circulation over the buffer tank and between the secondary connections a secondary circulation over the heat generating device, wherein coupled to the unit control is a primary electronic flow sensor which is incorporated between the primary connections and from which an electronic signal can be received as a measure of the primary circulation, and wherein coupled to the unit control is a secondary electronic flow sensor which is incorporated between the secondary connections and from which an electronic signal can be received as a measure of the secondary circulation.

6. Heating system according to one or more of the preceding claims, characterized in that the electronic connection is provided by an adapter unit inside the interface unit which connects the hydraulic installation electrically to the control device of the heat pump.

7. Heating system according to one or more of the preceding claims, characterized in that the hydraulic installation comprises inside the unit housing piping in which at least a pump, an expansion tank and various accessories such as electronic control valves, electronic sensors, filters, separators and fittings are incorporated.

8. Heating system according to one or more of the preceding claims, characterized in that the heat pump is coupled to the heat generating device only via the interface unit, and optionally a buffer tank provided externally of the interface unit.

9. Heating system according to one or more of the preceding claims, characterized in that the heat pump comprises an air / water heat pump or a water / water heat pump.

10. Interface unit for application in a heating system according to one or more of the preceding claims, comprising a unit housing and a hydraulic installation which is at least substantially enclosed by the unit housing and wherein primary connections are provided for connection of respectively the feed and return conduit of a heat pump, and wherein secondary connections are provided for connection of respectively a feed and return conduit of a heat generating device, and comprising a unit control with an electronic connection for coupling to the control device of the heat pump for the purpose of control information, wherein the hydraulic installation comprises inside the unit housing one or more components, controlled by the unit control, from a group of piping, pumps, expansion tanks, buffer tanks and accessories such as electronic control valves, electronic sensors, filters, separators and fittings.

Images