System for controlling the water temperature of a utilisation unit and water temperature control device for same

Abstract

The invention relates to a system (1) for controlling the water temperature of at least one utilisation unit (2) of a plurality of utilisation units (2) of a building, wherein at least one exhaust air device (4) of a ventilation system is provided in the utilisation unit (2). The exhaust air in the ventilation system can be supplied to at least one heat pump (10, 10', 10'') for energy recovery, which contributes at least in part to the temperature control of the water used in the utilisation unit (2). The exhaust air from the utilisation unit (2) is discharged via the exhaust air device (4) to a central main air duct (6) and / or decentrally to the environment of the utilisation unit (2). At least one heat pump (10) associated with the utilisation unit (2) is connected to the exhaust air device (4) in an air-guiding manner. A heat exchanger (47) of the heat pump (10), acting as a condenser, is connected via connecting lines (18, 19) to at least one decentralised flow and temperature control station (20) arranged in the utilisation unit (2), so that energy recovered from the exhaust air can be output to the decentralised flow and temperature control station (20). The decentralised flow and temperature control station (20) is fluidically connected by its flow and return lines to a central buffer tank (34) assigned to the entire building. The invention also relates to a suitable water temperature control device.

Description

[0001] Description

[0002] System for water tempering of a usage unit and water tempering device therefor

[0003] The subject matter of the invention is a system for controlling the water temperature of a usage unit according to the preamble of patent claim 1 and a water temperature control device for this purpose for use in a usage unit of a building.

[0004] In the following, a unit of use is defined as a self-contained sequence of common rooms available for use by one person or a group of people. These can be, for example, self-contained apartments, granny flats, offices, medical practices, commercial units, or similar units within a building or within a building, such as an apartment building.

[0005] DE 44 37 845 A1 shows a system for air conditioning at least one usage unit, preferably a house, wherein at least one exhaust air device of a ventilation system is present in the usage unit. A controllable exhaust air flap is arranged on the exhaust air device and the exhaust air is conveyed downwards within an exhaust air shaft through an extraction device into a heating center, where the exhaust air is fed to a heat pump for energy recovery. This heat pump contributes at least partially to the hot water preparation of the usage unit, with the main energy being supplied by various heat sources, e.g. heat pump, pellet boiler, or other renewable energies. This heated heating water is then supplied to the consumers by means of the circulating pumps via mixers and solenoid valves. In the following, the term consumer is understood to mean a heating system, preferably underfloor heating, and / or fittings that provide heated water.

[0006] 99% of all newly built multi-story residential buildings are equipped with a ventilation system to ensure the minimum air exchange rate. However, approximately 70% of these systems (assumed) do not have heat recovery, as systems with supply and exhaust air with heat recovery are very expensive. However, legislation will soon make heat recovery mandatory, so there is a need for an economical technical solution.

[0007] Although a generic system for controlling the water temperature in a utility unit is known from DE 10 2021 107 698 A1, this published application concerns the use of district heating. Furthermore, DE 10 2021 107 698 A1 shows a heat exchanger used to heat the refrigerant. Furthermore, according to this application, the heat provided by the heat pump is transferred to a hot water storage tank in the utility unit. Thus, there is still a need for a cost-effective technical solution.

[0008] The invention is based on the object of providing a system for controlling the water temperature of a utility unit using known energy sources to ensure high and economical energy utilization. Furthermore, a suitable water temperature control device is to be specified.

[0009] The object is achieved according to the invention by the features of the independent patent claims, while advantageous embodiments and further developments of the invention can be found in the subclaims.

[0010] An advantageous feature is that with a plurality of usage units, the

[0011] The exhaust air from each usage unit is guided to a central main air duct via an exhaust air device, and a decentralized heat pump assigned to each usage unit is connected to the exhaust air device in an air-conducting manner. A heat exchanger of the decentralized heat pump is connected via connecting lines to at least one decentralized flow and temperature control station arranged in the usage unit, so that the energy recovered from the exhaust air by the heat pump can be transferred to the decentralized flow and temperature control station. The decentralized flow and temperature control station, with its flow and return lines, is fluidly connected to a central storage tank assigned to the entire building, in particular a buffer tank.

[0012] In the following, water tempering is understood to mean both the heating and cooling of water, such as service water, fresh water, heating fluid or the like.

[0013] The connection of the decentralized flow and temperature control station to the central storage tank can be realized by a fluid-conducting connection between the decentralized flow and temperature control station and a central supply and / or return line of the building, extending from the central storage tank to the usage unit. Additional decentralized flow and temperature control stations from other usage units of the building can also be connected to the central supply and / or return line of the building.

[0014] The system according to the invention advantageously links the areas of ventilation, heating, hot water, and fire protection. Fire protection components can be designed more simply. The energy required for water temperature control is reduced. Compared to existing solutions, a more energy-efficient system is thus provided. Furthermore, the modularity of the system and its simple design reduce installation and maintenance costs. Instead of a large, centrally located heat pump or a cross-flow heat exchanger, small heat pumps are used in the exhaust air systems of the individual utility units.

[0015] The heat pump used has very small dimensions and can be integrated, for example, into a ventilation shaft. However, the heat pump is preferably installed together with the flow and temperature control station in a common cabinet or rack. This allows the heat pump to be installed in a space-saving unit, hydraulically integrated into the heating system, and capable of heating the required water to the required temperature.

[0016] The building services system can include more than one of the decentralized heat pumps described above, which improves the modulation of the output of the decentralized heat pumps and enables the heat pumps to be operated with high efficiency even with different volume flows and different amounts of heat that can be recovered from the waste heat.

[0017] The exhaust air flow rates and the heating and / or hot water requirements determine the flow rate of the micro heat pump. In this discussion, heat pumps used decentrally for energy recovery from exhaust air are also referred to as micro heat pumps. Such a micro heat pump can, for example, have a heating and / or cooling capacity in the range of 100 W to 10 kW.

[0018] Fresh air is supplied through outside air vents, and the humidity-controlled air is extracted via a central fan on the roof. The centralized exhaust air system thus reduces the number of components required for extracting the exhaust air. Control is also simplified, and the components can be operated more efficiently. Consequently, centralized air extraction via a central main air duct is overall more energy-efficient and cost-effective than decentralized exhaust air ducting.

[0019] The system according to the invention combines the advantages of a central exhaust air system, in which the exhaust air is discharged via a central main air duct, with decentralized heat recovery by micro heat pumps in the usage units.

[0020] Discharging the exhaust air via a central main air duct also has beneficial effects on fire protection in the building.

[0021] If several decentralized units are connected to a central supply and / or exhaust air system and thus interconnected by air flow, the uncontrolled spread of fires and exhaust gases via the central supply and / or exhaust air system across multiple units must be prevented. To achieve this, fire protection devices must be provided in the supply and exhaust air systems of the respective units. This increases the effort required to ensure compliant building fire protection.

[0022] If the supply air is supplied decentrally within the respective occupancy unit via supply air devices, but the exhaust air is simultaneously removed via a central exhaust air system with a main air duct, only the exhaust air devices of the occupancy units are connected via the central exhaust air duct system. The associated fire protection requirements are comparatively low. Consequently, the advantages of a centralized exhaust air duct can be utilized without having to accept any significant disadvantages. At the same time, with a decentralized supply air duct, so-called ceiling bulkheads can be advantageously used as fire protection devices. These require less maintenance, are simpler to install, and are cheaper to procure than fire dampers, which would be required with a centralized supply air duct.Additionally or alternatively, the exhaust air can be discharged decentrally from a usage unit, preferably through an exterior wall of the building, for example, into the building's ambient air. For this purpose, a suitable exhaust air device, such as a fan, can be connected to an exterior wall of the usage unit and / or the building's exterior wall. This exemplary embodiment is also advantageous with regard to fire protection because the requirements for ensuring compliant building fire protection are low in this case.

[0023] In one embodiment, even with decentralized exhaust air extraction, the exhaust air device is located in close proximity to the decentralized heat pump and connected to it via air flow. For example, the exhaust air device can be located in a shared rack or cabinet with the heat pump and / or the flow and temperature control station of the utilization unit. In this case, the exhaust air from the utilization unit can be drawn in by the exhaust air device, passed through a heat exchanger of the heat pump, and then released, for example, into the ambient air of the building.

[0024] Alternatively or additionally, an exhaust air device, for example a fan, can be arranged at a distance from the heat pump and connected to the heat pump in an air-conducting manner, for example in a wall that separates a bathroom in the usage unit from other rooms. In this case, the exhaust air from the usage unit is pushed by the exhaust air device towards the heat pump, where it is passed through a heat exchanger and then released, for example into the environment of the usage unit or the environment of the building. The operating principle of the heat pump is based on a closed heating system, with the heat pump extracting energy from the exhaust air and making it usable for the heating system. To do this, it raises the extracted ambient energy to a required temperature level using electrical energy and transfers the heat to at least one consumer, preferably to an underfloor heating system.The thermal energy is thus transferred to the floor via the underfloor heating pipes, which heats up the unit.

[0025] As the heat is transferred to the usage unit, the temperature of the heating water drops. This water flows back within the heating circuit and is heated again by the energy exchange with the coolant of the heat pump.

[0026] The available exhaust air and its heat energy depend on the size of the unit. For example, approximately 10 W of heat can be extracted per square meter of living space, assuming a living space of 50 m². 2 it is 500 W and at 150 m 2 already 1,500 W, which are theoretically available as heat energy.

[0027] In order to optimally utilize the heat pump, a flow and temperature control station is integrated into the water tempering system of a usage unit, which is energetically coupled to the heat pump, the central heating plant and the consumers.

[0028] For this purpose, the flow and temperature control station can be hydraulically connected to a heat exchanger of the heat pump via connecting lines, so that energy recovered from the exhaust air by the heat pump can be transferred from the heat pump's refrigerant to the liquid in the connecting lines in the heat exchanger and delivered to the central flow and temperature control station. Preferably, the flow and temperature control station is hydraulically connected to the heat pump's heat exchanger, which acts as a condenser. In this case, the transfer of thermal energy to the fluid flowing to or from the flow and temperature control station causes the heat pump's refrigerant to at least partially change from a gaseous to a liquid state, resulting in a particularly simple heat pump design.

[0029] The heat pump is connected via pipes to the heating center, which comprises at least one heat source and a storage tank. The heat pump and the heating center are connected via pipes, and preferably also hydraulically or fluidly, to the flow and temperature control station, which regulates the supply of tempered water to the consumers in a unit. The water flowing through the flow and temperature control station is thus heated by the heat pump and / or the heating center.

[0030] Through the direct hydraulic integration of the heat pump into the heating system, the thermal energy recovered from the exhaust air by the heat pump can be provided directly to the flow and temperature control station of the usage unit, from where the thermal energy is further distributed to the heating circuit of the usage unit or to other thermal consumers of the usage unit.

[0031] The thermal energy provided by the heat pump is either used directly in the heating circuit of the unit or transferred to the building's central buffer storage via the flow and temperature control station. This eliminates the need for a decentralized buffer storage for buffering thermal energy, particularly in the unit or in the heat pump. The building's central buffer storage can therefore preferably be connected to each of the decentralized flow and temperature control stations provided via a supply line or a return line, respectively, so that the excess thermal energy recovered from the exhaust air in the individual decentralized units can be stored in the shared, central buffer storage.

[0032] In tall buildings, such as high-rise buildings with multiple floors, fluid-carrying pipes can be subject to high pressures. To counteract this, the central buffer storage can have multiple storage reservoirs distributed across the height of the building. Each storage reservoir can be assigned to different usage units of the building, with the storage reservoirs being arranged at different heights. This reduces the pressure difference that must be bridged in the central supply and return lines between the respective central storage reservoir and the assigned decentralized flow and temperature control stations of the usage units. This is advantageous, for example, in a building with multiple floors, such as a high-rise building, because the pumps used to pump the water can be smaller.

[0033] Thus, the energy generated by the heat pump that is not directly supplied to the usage unit can be stored centrally in the storage tank, saving space and costs. In particular, compared to systems with decentralized buffer and / or hot water storage in the usage unit, less space is required when using a system according to the invention. The space available in a usage unit can therefore be used for other purposes. Due to the small space requirement, it is also easy to retrofit the system for water temperature control in existing buildings. For example, the central storage tank in the system is used to cover peak loads. This storage tank is preferably a stratified storage tank, but can also be a buffer storage tank.

[0034] By using the heat pump and storage tank, the primary energy source, e.g., a boiler, a central heat pump, or a gas condensing boiler, can be made smaller, for example, with a reduction of approximately 33-50% compared to conventionally used boilers.

[0035] The heat recovery system formed by the heat pump can, for example, represent the base load supply, whereby the central primary heat source can be significantly reduced, since it only covers the remaining heat demand, in particular the thermal peak loads.

[0036] A particular advantage is that, particularly in passive houses, i.e. houses in which the majority of the heat requirement is covered by “passive” sources such as solar radiation and waste heat, a primary energy source can be completely dispensed with, since the heat energy generated by the decentralized heat pumps is sufficient for heating.

[0037] The term "spread" of a heat pump refers to the temperature of the heating water. It describes the difference between the temperature in the flow and return lines of the heat pump.

[0038] The heat pump harnesses the ambient heat in the exhaust air by evaporating a refrigerant and compressing it with a compressor, thus raising it to higher temperatures. It operates particularly efficiently with a low flow temperature in the heating circuit. This reduces the load on the compressor, thus reducing electricity consumption. The room air serves as the heat source for the decentralized heat pump in the residential units. The heat pump can then supply the heating system and, additionally or alternatively, the decentralized hot water system.

[0039] The system is controlled and regulated via the flow and temperature control station, which is a link between the decentralized heat pump, the supply of a usage unit and the central primary energy source.

[0040] For this purpose, the decentralized flow and temperature control station can be hydraulically connected via lines both to the heat pump arranged in a usage unit, in particular to a heat exchanger of the heat pump, as well as to thermal consumers of or in the usage unit, as well as to a central thermal storage unit of the building.

[0041] The decentralized flow and temperature control station can have various valves by means of which the flow of heat transfer fluid, in particular water, to / from the heat pump, to / from the central thermal storage, and to / from the consumers of the usage unit can be controlled. For example, excess thermal energy provided by the heat pump, which is not used for heating in the usage unit, can be used to raise the temperature of a central return line of the building by appropriately switching the valves in the decentralized flow and temperature control station, and thus be transferred to the building's central buffer storage.

[0042] A sophisticated control system regulates the decentralized heat pump with a ventilation system of a residential unit as needed. This can be done in a modulating manner and, if necessary, 24 hours a day, 7 days a week. The heat pump raises the thermal energy of the exhaust air to a higher temperature level using electrical energy. This creates a significant surplus of heating energy. The lower the required temperature, the less energy the heat pump needs to consume. The heat pump's power supply can be decentralized or centralized. It is controlled via a controller that is installed, for example, in the heat pump, ventilation system, apartment station, or building management system. Control can also be decentralized or centralized.

[0043] The coefficient of performance, known as the coefficient of power or performance (COP for short), is the ratio of the generated heat or cooling power to the electrical power used.

[0044] In the following, the COP value is used in relation to a heat pump with a lower temperature difference, where the decisive factor is the air volume in combination with the heat pump's COP values. The efficiency of the heat pump at heating temperature achieves an optimal COP. In general, the heat pump provides the heating temperature as required. This is controlled by the flow and temperature control station and recorded by at least one sensor.

[0045] In an exemplary embodiment, each usage unit has its own adjustable flow and temperature control station, which serves as a controller for the distribution of the individual energy flows. The adjustable flow and temperature control station thus provides a standardized interface for connection to a central heating system, in particular to a central supply and / or return line of the building.

[0046] Hot water can be heated centrally or decentrally via heat pumps in the individual units. If sufficient energy isn't available, the desired temperature is reached via an instantaneous water heater.

[0047] This makes it possible for the water flowing through the flow and temperature control station to be additionally heated by a flow heater located in the flow and temperature control station.

[0048] The flow and temperature control station supplies the heated water to the consumers via circulation pumps, mixers and solenoid valves.

[0049] The flow and temperature control station is coupled to the buffer tank and / or domestic hot water tank, which provides and / or stores heated water.

[0050] Excess heat from the heat pump can be diverted to the buffer storage of the heating center to make the heat source available for peak loads in the usage unit.

[0051] All flow and temperature control stations in the building can communicate with each other and transmit values ​​to a master controller, preferably located in the heating center. This can be done via IoT, wireless, or wired.

[0052] The valves and turbines that provide the flow rate are controlled by a dedicated control system. This determines whether the decentralized heat pump directly serves the heating system or whether the return temperature for the central storage tank is raised. The requirements are determined by the return temperature controller and the temperature controller in the flow and temperature control station. A weather-compensated control system can regulate the system temperatures based on the optimal COP value. The control system balances all available energy sources—i.e., the heat pump, heat source, and / or buffer tank—to achieve maximum efficiency.

[0053] Each unit has at least one, preferably two, heat meters that record the energy fed in, generated, and consumed. Thus, the user also benefits from this system, as any surplus heat energy can be stored in the central storage facility, thereby reducing utility costs.

[0054] The energy recovered by the decentralized heat pump can be recorded separately for each assigned unit of a building. For example, the portion of the energy recovered by the heat pump that is consumed decentrally in the unit can be recorded separately from the portion of the recovered energy that is made available to a central buffer storage facility in the building.

[0055] The recorded energy quantities can be assigned a monetary equivalent. Based on this, for example, the ancillary housing costs of tenants of a usage unit can be reduced if energy recovered by a decentralized heat pump assigned to the usage unit is fed into a central buffer storage of the building. Such recording of revenues, broken down by usage unit, is particularly advantageous if individual usage units of a building are equipped with water tempering devices for heat recovery and other usage units of the building do not have such water tempering devices. Operation with a decentralized heat pump has another advantage. It can be used not only for heating but also for cooling or tempering, since reversible operation of the heat pump is also possible. In this case, cold water flows through the pipes of the underfloor heating.It heats up and thus removes heat from the living spaces of the unit. This significantly improves the indoor climate in summer. This effect can be further enhanced by a heat pump. This absorbs the heat energy from the return water and transfers it via the exhaust air to the environment outside the unit. This cools the water down again before it flows through the underfloor heating again.

[0056] The following describes the individual operating modes of the system in conjunction with underfloor heating, which acts as a consumer, using various examples. This list is not exhaustive. The first and second valves used in the flow and temperature control station are mixing valves, preferably control valves with a pulse input. The heat pump in the examples delivers a constant 1,500 watts. The temperature and water quantity supplied to the heater are controlled as needed via the flow and temperature control station by switching the first and second valves accordingly. Control is therefore via a turbine controller with volume flow measurement and control valves, in particular the first and second valves, which open and close as needed.

[0057] A consistent flow rate without temperature fluctuations is achieved. Any excess heat from the heat pump, if available, is fed into the system via the return flow (return flow boost).

[0058] A heat meter, which can be operated in both directions, for example, runs in reverse, thus reducing the measured energy consumption directly at the user's location. This can also be achieved with two built-in heat meters by comparing the heat quantity differences and thus demonstrating the yield.

[0059] Winter full load:

[0060] If the underfloor heating is set to full load in winter, the heat demand of the underfloor heating exceeds the heat pump output. The heat load required for the unit, assuming a size of 150 m, is 2 , for example 4,500 W. However, the heat pump can only provide 1,500 W.

[0061] Since more energy is required than can be provided by the decentralized heat pump, the remainder of the required heat quantity is requested from the heating center by the flow and temperature control station, resulting in the following volume flows.

[0062] In this case, the underfloor heating system (at full load) requires 773 l / h. The decentralized heat pump provides a flow rate of 258 l / h at a 5 K temperature spread. This flow rate is heated in the heat pump and used directly in the unit (circulation). The missing energy for the unit's heat demand, in this case 515 l / h, comes from the central heating system.

[0063] Thus, the volume flows of the heat pump of 258 l / h and the heating center of 515 l / h are combined via a valve of the flow and temperature control station.

[0064] Via another valve in the flow and temperature control station, the flow rates are divided again after the return from the underfloor heating system: 258 l / h to the heat pump and 515 l / h to the central heating system. Winter - Partial Load I:

[0065] In this example, the heating demand is lower than the heat pump output. For example, a required heating load of 1,353 W for 150 m 2 This can occur, for example, at an outside temperature of 10°C. The heat pump provides 1,500 W and supplies 100% of the underfloor heating.

[0066] The decentralized heat pump produces a flow rate of 258 l / h at a 5 K differential. This flow rate is heated in the heat pump. A portion is used directly in the utility unit (partial circuit). The underfloor heating requires a partial load flow rate of 200 l / h. Thus, the heat pump's flow rate of 200 l / h is released via the first valve of the flow and temperature control station. The excess flow rate, in this case 58 l / h, is discharged to the central heating system, thereby increasing the return temperature of the central return flow to the central buffer tank.

[0067] Summer operation I:

[0068] The heat demand of the heating system is smaller than the heat pump output; in particular, in the example case shown, there is no need to operate the heating system due to warm outside temperatures.

[0069] The entire energy of the decentralized heat pump is transferred via the central return flow to the central buffer storage tank in the basement of the building by appropriately switching the first and second valves of the flow and temperature control station. The existing control system can maintain the storage tank at a specific temperature, for example, 40°C. This means that, depending on the heat demand, a temperature of 40°C can be provided from the buffer storage tank without intervention by the primary heat energy generator in the basement. The remaining temperature for the desired hot water is increased by the flow and temperature control station's instantaneous water heater. The decentralized heat pump operates with a very high COP value.

[0070] The decentralized heat pump delivers a flow rate of 258 l / h at a 5 K differential. This flow rate is heated in the heat pump and fed directly into the central heating system, increasing the return temperature of the central return flow to the buffer tank.

[0071] Summer operation II: (temperature control)

[0072] The decentralized heat pump produces a flow rate of 258 l / h at a 5 K spread. This flow rate is cooled in the heat pump and made available directly in the apartment by controlling the valves of the flow and temperature control station. In this case, 258 l / h.

[0073] Summer operation III:

[0074] In this operating mode, heat demand, including hot water preparation, is covered by integrating PV yield via the control of the flow and temperature control station.

[0075] The decentralized heat pump can produce higher flow temperatures than required for operating a radiant heating system. The control system regulates the desired flow temperature, possibly depending on the PV yield. By appropriately switching the valves in the flow and temperature control station, the high flow temperature is made available to the central storage tank. From this, a demand is generated via the decentralized flow and temperature control stations. The temperature in the storage tank is sufficient to provide the desired draw-off temperature without reheating. The primary energy generator, for example, a boiler or a central heat pump in a heating center, is not needed in summer.

[0076] Furthermore, a water temperature control device for use in a usage unit of a building is provided. The water temperature control device according to the invention can be used, for example, in new construction projects for water temperature control in usage units, such as new apartments. However, it is particularly advantageous that the water temperature control device can also be used as a retrofit kit in existing buildings. It is not necessary for all usage units of a building to be equipped with the water temperature control device. Rather, due to the flexible applicability and standardized connections of the water temperature control device, an individual decision can be made for each usage unit as to whether the water temperature control device should be used.

[0077] A water temperature control device comprises at least one heat pump, to which exhaust air from an exhaust air device of the utilization unit can be supplied for energy recovery. Furthermore, the water temperature control device comprises at least one decentralized flow and temperature control station, wherein the decentralized flow and temperature control station is connected to a heat exchanger of the heat pump via connecting lines. In an advantageous embodiment, the heat exchanger represents the condenser of the heat pump.

[0078] Consequently, energy recovered from the exhaust air by the heat pump can be transferred to the decentralized flow and temperature control station by transferring the thermal energy in the heat exchanger from the heat pump's refrigerant to the water in the connecting pipes. The decentralized flow and temperature control station provides various connections for integrating the water temperature control device into a water temperature control system:

[0079] Firstly, the decentralized flow and temperature control station can be fluidly connected to a central buffer tank assigned to the entire building, in particular via a central flow and / or return line of the building, which leads from the buffer tank to the usage unit in which the water temperature control device is installed. The decentralized flow and temperature control station can also be connected to at least one consumer of the usage unit, in particular an underfloor heating system, so that a tempered water quantity can be supplied to the consumer(s) of the usage unit via the flow and temperature control station serving as an interface.

[0080] Preferably, the heat pump and the flow and temperature control station, i.e., the entire water temperature control device, are arranged in a common mounting unit, in particular a rack, frame, cabinet, or the like. The water temperature control device is thus designed to be particularly space-saving, which provides the advantages described above during its use. Furthermore, the water temperature control device is easily transportable in this way. Furthermore, it can be prefabricated so that it can be delivered to a construction site ready for installation.

[0081] By means of the flow and temperature control station, water from the central buffer tank of the building can be mixed with water that has flowed through the heat exchanger of the heat pump and made available to at least one consumer of the usage unit.

[0082] The flow and temperature control station can have at least one first valve for mixing the volume flows from the decentralized heat pump and the central buffer storage, wherein the mixed volume flow can be provided to at least one consumer in the usage unit. The flow and temperature control station can have a second valve for dividing the volume flow returning from at least one consumer of the usage unit into volume flows to the decentralized heat pump and the central buffer storage.

[0083] By combining the flow and temperature control station and the heat pump, the heat pump can be optimally utilized because the energy can be stored centrally, which saves space and costs.

[0084] The required domestic hot water and heating temperatures can be controlled depending on the PV yield in order to always achieve optimal efficiency of all energy system components.

[0085] The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another.

[0086] In particular, statements made in connection with the system for water tempering of a usage unit should also be applicable to a water tempering device, and vice versa.

[0087] All information and features disclosed in the documents, including the abstract, in particular the spatial configuration depicted in the drawings, could be claimed as essential to the invention, provided they are novel, individually or in combination, compared to the prior art. The use of the terms "essential" or "according to the invention" or "essential to the invention" is subjective and does not imply that the features so named must necessarily be part of one or more patent claims. The invention is explained in more detail below with reference to drawings that merely illustrate one embodiment. Further essential features and advantages of the invention will become apparent from the drawings and their description.

[0088] They show:

[0089] Figure 1: schematic view of a heat pump according to the state of the art;

[0090] Figure 2: schematic view showing several decentralised heat pumps of different usage units;

[0091] Figure 3 : a functional representation of the connection between heat pump and station;

[0092] Figure 4: a functional representation of the system for water temperature control of at least one usage unit;

[0093] Figure 5: Block diagram of winter full load operation;

[0094] Figure 6: Block diagram of winter partial load operation;

[0095] Figure 7: Block diagram of summer operation of underfloor heating; and

[0096] Figure 8: Block diagram summer operation storage filling.

[0097] Figure 1 shows a prior art example. The exhaust air from a utilization unit 2 flows into the exhaust air device 4, which is installed in the floor or a wall. The exhaust air device 4 is connected to the supply line 5, which feeds at least the exhaust air from the exhaust air device 4 to an exhaust air heat pump 10', which draws in the exhaust air using built-in fans. Thus, heat energy recovery can take place based on the thermal energy present in the exhaust air.

[0098] The heat energy thus obtained can be fed into an air-to-water heat pump, which in the example shown consists of a 10" indoor unit and a 10' outdoor unit. Thus, the 10" + 10' air-to-water heat pump can be supported with the heat energy obtained from the exhaust air, for example, to temper the water for the heating system.

[0099] Figure 2 shows a building with multiple units 2. Each unit 2 is supplied with fresh air via a decentralized supply air device 3, which exits the unit 2 as exhaust air via the exhaust air device 4. According to the invention, a heat pump 10 is located in the exhaust air device 4 for energy recovery. The exhaust air releases its thermal energy via this heat pump 10 before being guided via the supply line 5 into a main air duct 6 within the supply shaft. This vertically running main air duct 6 opens into a roof box 8 until it finally flows out of the building into the environment via a central air outlet 9.

[0100] The supply lines 5 of the other usage units 2 also open into the main air line 6, whereby each usage unit 2 has a heat pump 10 in its exhaust air device 4.

[0101] The arrangement described here, which provides for a decentralized supply of supply air via the supply air devices 3 and a central discharge of the exhaust air via the exhaust air devices 4 to the main air duct 6, is advantageous with regard to fire protection in a building. As soon as several decentralized usage units 2 are connected to a central exhaust air system and thus interconnected by air flow, the uncontrolled spread of fires and exhaust gases via the central exhaust air system across several usage units 2 must be prevented. In such a case, it is therefore necessary to install fire protection devices in the supply and exhaust air devices 3, 4 of the respective usage units 2.

[0102] When supply and exhaust air are each supplied via a central system, fire dampers often have to be used as fire protection devices. These are complex to construct and require intensive maintenance. The installation and operation of fire dampers are therefore expensive.

[0103] If, however, as in the illustrated embodiment, the supply air is supplied decentrally in the respective utilization unit 2 via supply air devices 3, but a central exhaust air system with a main air duct 6 is present at the same time, only the exhaust air devices 4 of the utilization units 2 are connected via a central system. Consequently, ceiling bulkheads can be used as fire protection devices, which, compared to fire dampers, require less maintenance, are simpler to construct, and are less expensive to procure. At the same time, however, the advantages of a central exhaust air system described above are achieved.

[0104] Figure 3 shows a functional diagram of the connection of a decentralized heat pump 10 with a decentralized flow and temperature control station 20.

[0105] Each usage unit 2 has a flow and temperature control station 20, which is energetically coupled to the respective heat pump 10 and, in particular, is fluidly connected to a heat exchanger 47 of the heat pump 10 via connecting lines. The heat pump 10 is connected to the return line of an underfloor heating system via the connecting line 18 and to the inlet of the underfloor heating system 30 via the connecting line 19, and is thus integrated into the heating circuit.

[0106] The exhaust air is preferably sucked into the heat pump 10 via a fan (not shown), where the heat energy is extracted from the exhaust air.

[0107] In the heat pump 10, the energy is passed through a heat exchanger 46, which extracts the heat from the air and transfers it to the refrigerant, which circulates in the closed refrigerant circuit 15 within the heat pump 10.

[0108] In the evaporator 11 of the first heat exchanger 46, the refrigerant transforms into a gaseous state even at low temperatures and is fed to the compressor 13. The compressor 13, which is formed by an electrically driven compressor, increases the pressure in the gas, which heats up considerably in the process.

[0109] Electrical energy is required to operate the compressor 13, which is also converted into thermal energy.

[0110] The heated and gaseous refrigerant is passed to the second heat exchanger 47 and there transfers the heat energy to the heating water of the heating circuit 17.

[0111] The refrigerant in the condenser 12 of the second heat exchanger 47 becomes liquid again, and the high pressure drops. The remaining pressure is released in an expansion valve 14.

[0112] The now liquid refrigerant returns to the first heat exchanger 46 or evaporator 11 and again absorbs heat energy from the exhaust air of a usage unit 2. Figure 4 shows a simplified representation of the system for controlling the water temperature of a usage unit 2. The heat pump 10 produces heat from the exhaust air of the usage unit 2 and transfers it to the heating water of the underfloor heating system 30 of the usage unit 2. The cooled exhaust air flows through the air outlet 9 into the building's surroundings.

[0113] The cooled heating water from the return flow of the underfloor heating system 30 is fed via the connecting line 18 to the heat exchanger 47 of the heat pump 10 and, as heating circuit 17, absorbs the thermal energy of the coolant and flows back into the flow of the underfloor heating system 30 via the connecting line 19.

[0114] If the energy provided by heat pump 10 is insufficient to meet the heating requirements of heater 30 in usage unit 2, flow and temperature control station 20 can add additional heated water from central heating system 32. The combination of centralized and decentralized heat provision makes system 1 flexible and expandable. Furthermore, system 1 is particularly energy-efficient due to the recovery of the thermal energy contained in the exhaust air and the case-dependent control of the flow and temperature control station.

[0115] Located in the heating center 32 is the boiler 35, which heats this water, which is then fed from the buffer tank 34 via the flow line 28 to the flow and temperature control station 20, where it is mixed with the water heated by the heat pump 10 via a valve 37 and then fed into the underfloor heating system 30. After passing through the underfloor heating system, this volume flow is divided again via a second valve 38 of the flow and temperature control station 20, with, for example, part of the volume flow going to the heat pump 10 and part being fed back into the heating center 32, in particular into the buffer tank 34, via the central return line 29. The volume flows into and out of the heating center are measured by the measuring station 33 in the heating center 32, which transmits its values ​​to the flow and temperature control station 20, in particular to a control or controller 21 of the flow and temperature control station 20.

[0116] If the heat pump 10 provides more heat energy than is required by the underfloor heating 30, the excess heat energy is stored in the buffer storage 34 via the central return 29 and is available there, for example, for the consumers 31', 31“ and 31'“.

[0117] The consumer 31' is formed by a shower, which can draw its hot water from the buffer tank 34. Thus, the flow and temperature control station 20 controls the supply of heated water, which is supplied to the consumer 31' via the hot water pipe 27 after passing through the station 20.

[0118] The consumer 31'", which is formed by a toilet, requires only drinking water, which is provided via the drinking water line 26 by the station 20, which controls the flow of the drinking water line 26.

[0119] Depending on the temperature level prevailing in the buffer storage 34, the thermal energy stored in the buffer storage 34 can be used to support the heating of a usage unit 2 or to provide hot water for a usage unit 2.

[0120] Figures 5 to 7 show various applications of system 1 for controlling the water temperature of at least one usage unit 2. The heat pump 10 transfers the generated heat via a heat exchanger 47 to the water in the heating circuit 17, represented by the flow line 42 of the heat pump. By means of a circulation pump (not shown), the water is continuously moved in a closed circuit through the piping of the underfloor heating system 30 and the heat exchanger 47 of the heat pump. In the example shown, the flow rate is the amount of water that flows through the heat exchanger in a specific unit of time. The unit of measurement is usually liters per hour (1 / h). Instead of flow rate, the term volume flow, used in specialist circles, is used below.

[0121] Thus, in the examples shown in Figures 5 to 7, a volume flow of 258 l / h is assumed, which passes through the heat exchanger 47 of the heat pump 10. A spread of 5 Kelvin is assumed.

[0122] The system 1 comprises an exchanger 41 for hot water preparation, which can be arranged in particular in the flow and temperature control station 20. The exchanger 41 for hot water preparation is connected via lines to the fluid circuit flowing through the heat pump 10. By means of a hot water valve 39, a fluid connection can be established or interrupted between the exchanger 41 and the flow and return lines 42, 43 of the heat pump 10 or the flow and return lines 44, 45 of the underfloor heating system 30. In this way, excess thermal energy provided by the heat pump 10 can be used for hot water preparation.

[0123] In Figure 5, this volume flow is thus heated in the heat pump 10 and used directly for heating the usage unit 2 (circuit). In this winter example, the underfloor heating system 30 is running at full load and requires a volume flow of 773 l / h via the return line 45.

[0124] In order to provide the volume flow for the underfloor heating 30, the volume flow of 258 l / h of the flow 42 of the heat pump 10 and the volume flow of 515 l / h of the flow 28 of the heating center 32 provided from the buffer tank 34 are mixed via the valve 37 and fed to the underfloor heating 30 via the return 45.

[0125] The missing energy for the heat requirement of the underfloor heating 30, in this case 515 l / h, thus comes via the flow 28 from the heating center 32, since the heat generation of the heat pump 10 is not sufficient.

[0126] After passing through the underfloor heating system 30, the volume flows are divided again via the valve 38, with 258 l / h being led via the decentralized return 43 to the heat pump 10 and the remaining 515 l / h being led via the central return 29 to the heating center 32.

[0127] The volume flows, in particular the valves 37, 38, are controlled via the control 21 of the flow and temperature control station 20.

[0128] Taking into account a spread of 5K, in the example shown the volume flow of 515 1 / h can also be understood as 3000W and the volume flow of 258 1 / h as 1500W for a 773 1 / h or 4500W requirement of the underfloor heating 30.

[0129] The volume flow of the return 43 is recorded via a turbine 36.

[0130] Figure 6 shows an application example for winter partial load operation. The decentralized heat pump 10 produces a volume flow of 258 l / h at a temperature spread of 5 K. This volume flow is heated in the heat pump 10 and a portion is used directly in the usage unit 2 (partial circuit). The excess volume flow is discharged to the heating center 32, which increases the return temperature of the central return 29, in this case by the volume flow of 108 l / h. The underfloor heating 30 requires a volume flow of 150 l / h in this partial load case. Thus, the volume flow of 150 l / h is released from the flow 42 of the heat pump 10 via the valve 37, and the excess 108 l / h of the volume flow of the heat pump 10 flows via the return 29 into the heating center 32 and is stored there in the buffer tank 34.

[0131] After leaving the underfloor heating 30, the volume flow of 150 l / h flows as a flow to the valve 38, where this volume flow is mixed with a volume flow of 108 l / h and returns to the heat pump 10 as a volume flow of 258 l / h via the return 43.

[0132] Taking into account a spread of 5K, in the example shown the volume flow of 108 1 / h can also be understood as 628W and the volume flow of 258 1 / h as 1500 W for a 150 1 / h or 872 W requirement of the underfloor heating 30.

[0133] Figure 7 shows an application example for summer operation, in which the underfloor heating system 30 is controlled. The decentralized heat pump 10 produces a volume flow of 258 l / h at a temperature spread of 5 K. This volume flow is cooled in the heat pump 10 and used directly in the utilization unit 2 (circuit). There is no excess volume flow that is discharged to the heating center 32. The unused heat energy of the exhaust air is further increased by the waste heat from the heat pump 10 and discharged via the supply line 5 to the main air line 6.

[0134] In this case, the underfloor heating system 30 requires a flow rate of 258 l / h. Thus, the flow rate of 258 l / h is released from the flow line 42 of the heat pump 10 via the valve 37. After leaving the underfloor heating system 30, the flow rate of 258 l / h flows as the flow line 44 to the valve 38, where it returns to the heat pump 10 as a flow rate of 258 l / h via the return line 43.

[0135] Taking into account a spread of 5K, the volume flow of 258 1 / h in the example shown can also be understood as 1500W.

[0136] Figure 8 shows summer operation, where the energy generated by the heat pump 10 is transferred to the central buffer storage tank 34 in the heating center 32 in the basement via a temperature increase in the central return line 29. The existing control system allows the buffer storage tank 34 to be maintained at a specific temperature, which may be, for example, 40°C. This means that, depending on the heat demand, hot water at 40°C, for example, can be provided from the buffer storage tank 34 without the intervention of the boiler as the primary heat energy generator.

[0137] The remaining temperature for the desired hot water is increased by the flow and temperature control station 20, which is installed in or near the usage unit 2 and features an instantaneous water heater. The heat pump 10 operates with a very high COP value.

[0138] Thus, at a 5 K temperature difference, the decentralized heat pump 10 produces a flow rate of 258 l / h. This flow rate is heated in the heat pump and transferred directly to the heating center 32 via the flow line 42 and the return line 29, thus increasing the return temperature. In this case, the flow rate is 258 l / h.

[0139] Underfloor heating 30 is not required. Valve 37 opens the path to heat pump 10, and the total flow rate of 258 l / h is introduced via return line 43. The flow rate is measured by turbine 36.

[0140] Valve 38 is closed.

[0141] Taking into account a spread of 5K, the volume flow of 258 1 / h can be considered as 1500 W in the example shown.

[0142] List of reference symbols

[0143] 1 system

[0144] 2 usage units

[0145] 3 Supply air device

[0146] 4 Exhaust air device

[0147] 5 Supply line

[0148] 6 Main air line

[0149] 7 Supply shaft

[0150] 8 roof boxes

[0151] 9 Air outlet

[0152] 10, 10', 10", 10'" heat pump

[0153] 11 evaporators

[0154] 12 Condenser (condenser)

[0155] 13 compressors

[0156] 14 Relief valve

[0157] 15 Refrigerant circuit

[0158] 16 Fluids

[0159] 17 Heating circuit

[0160] 18 connecting line

[0161] 19 connecting line

[0162] 20 flow and temperature control stations

[0163] 21 Regulation

[0164] 22 heat meters

[0165] 23 heating circuit distributors

[0166] 24 valves (hot water)

[0167] 25 valves (cold water)

[0168] 26 Drinking water pipe

[0169] 27 Hot water line

[0170] 28 Heating flow Heating return Underfloor heating, 31', 31", 31'" Consumer Heating center Measuring station Buffer storage Boiler

[0171] Turbine (1) Valve (4) Valve (5) Hot water valve

[0172] Bypass flow exchanger (to hot water) flow (of 10) return (of 10) flow (of 30) return (of 30) heat exchanger heat exchanger

Claims

Claims 1. A system (1) for controlling the water temperature of at least one usage unit (2) of a plurality of usage units (2) of a building, wherein at least one exhaust air device (4) of a ventilation system is present in the usage unit (2), wherein the exhaust air in the ventilation system can be fed to at least one heat pump (10, 10', 10") for energy recovery, which contributes at least partially to the temperature control of the water used in the usage unit (2), wherein the exhaust air of the usage unit (2) can be discharged via the exhaust air device (4) i) to a central main air duct (6), in particular ii) and / or can be discharged by means of a decentralized air duct from the usage unit (2) through a building exterior wall to the ambient air of the building (1), a decentralized heat pump (10) assigned to the usage unit (2) is connected to the exhaust air device (4) in an air-conducting manner,a heat exchanger (47) of the decentralised heat pump (10) acting as a condenser (12) is connected via connecting lines (18, 19) to at least one decentralised flow and temperature control station (20) arranged in the usage unit (2), so that energy recovered from the exhaust air can be delivered to the decentralised flow and temperature control station (20), and the decentralised flow and temperature control station (20) is connected with its flow and return lines in a fluid-conducting manner to a central buffer storage tank (34) assigned to the entire building.

2. System according to claim 1, characterized in that the heat pump (10) is energetically connected via lines (18, 19, 28, 29) to a heating center (32) which comprises at least one further heat source, in particular a boiler (35) and the buffer storage (34).

3. System according to claim 1 or 2, characterized in that the heat pump (10) and the heating center (32) are energetically connected to the flow and temperature control station (20) which controls the supply of the tempered water quantity to the consumers (30, 31, 31", 31") in a usage unit (2).

4. System according to one of claims 1 to 3, characterized in that the consumer is a heating system, in particular an underfloor heating system (30), the flow and return of which are energetically coupled to the heat pump (10).

5. System according to one of claims 1 to 4, characterized in that the water flowing through the flow and temperature control station (20) can be heated by the heat pump (10) and / or by the heating center (32).

6. System according to one of claims 1 to 5, characterized in that the water flowing through the flow and temperature control station (20) can be additionally heated by a flow heater present in the flow and temperature control station (20).

7. System according to one of claims 1 to 6, characterized in that the flow and temperature control station (20) supplies the heated water to the consumers by means of circulation pumps via mixers and solenoid valves.

8. System according to one of claims 1 to 7, characterized in that the flow and temperature control station (20) is coupled to the buffer tank 34, which provides stored and heated water.

9. System according to one of claims 1 to 8, characterized in that excess heat from the heat pump (10), which is not introduced into the usage unit (2), can be diverted and stored in the buffer storage (34) of the heating center (36).

10. System according to one of claims 1 to 9, characterized in that the heat pump (10) is a reversible heat pump.

11. System (1) according to one of claims 4 to 10, characterized in that the heat pump (10) cools the flow of the underfloor heating (30).

12. System (1) according to one of claims 1 to 11, characterized in that the required domestic water and heating temperatures can be controlled as a function of a PV yield and thus an optimal efficiency of all energetic system components can always be achieved.

13. System (1) for controlling the water temperature of at least one usage unit (2) in a building, wherein at least one exhaust air device (4) of a ventilation system is present in the usage unit (2), wherein the exhaust air in the ventilation system can be fed to at least one heat pump (10, 10', 10") for energy recovery, which heat pump contributes at least partially to the temperature control of the water used in the usage unit (2), characterized in that a plurality of usage units (2) are present, that the exhaust air of each usage unit (2) is discharged via the exhaust air device (4) to a central main air line (6), that a heat pump (10) assigned to the usage unit (2) is connected in an air-conducting manner to the exhaust air device (4), that the energy recovered from the exhaust air by the heat pump (10) can be delivered to at least one decentralized flow and temperature control station (20) arranged in the usage unit (2), and that the decentralized flow and temperature control station (20) is connected with its flow and return lines in a fluid-conducting manner to a central buffer storage tank (34) assigned to the entire usage unit (2).

14. Water temperature control device for use in a usage unit (2) of a building, comprising at least one decentralized heat pump (10), to which exhaust air from an exhaust air device (4) of the usage unit (2) can be supplied for energy recovery, and at least one decentralized flow and temperature control station (20), wherein the decentralized flow and temperature control station (20) is connected via connecting lines (18, 19) to a heat exchanger (47) of the decentralized heat pump (10) so that energy recovered from the exhaust air by means of the decentralized heat pump (10) can be delivered to the decentralized flow and temperature control station (20), wherein the decentralized flow and temperature control station (20) is fluidly connectable to a central buffer storage tank (34) assigned to the entire building, and wherein the decentralized flow and temperature control station (20) is connected to at least one consumer (30, 31, 31", 31") of the usage unit (2),in particular an underfloor heating system (30), for supplying a tempered amount of water.

15. Water tempering device according to claim 14, characterized in that the decentralized heat pump (10) and the decentralized flow and Temperature control station (20) are arranged in a common assembly unit, in particular rack, frame, cabinet or the like.

16. System (1) according to claim 1 or water tempering device according to claim 14 or 15, characterized in that by means of the decentralized Flow and temperature control station (20) Water from the central buffer tank (34) of the building is mixable with water that has flowed through the heat exchanger (47) of the decentralized heat pump (10) and can be made available to at least one consumer (30, 31, 31", 31") of the usage unit (2).

17. System (1) according to claim 13, or water tempering device according to one of claims 14 to 16, characterized by at least one of the features of claims 2 to 12.

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