System for tempering water of a usage unit and tempering device for same

Abstract

A system (1) for water temperature control of at least one usage unit (2) or a plurality of usage units (2) of a building is specified, wherein at least one exhaust air device (4) of a ventilation system is present in the usage 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 partially to the temperature control of the water used in the usage unit (2). The exhaust air from the usage unit (2) is discharged decentrally to the environment of the usage unit (2) via the exhaust air device (4). At least one heat pump (10) assigned to the usage unit (2) is connected to the exhaust air device (4) via an air supply.A heat exchanger (47) of the heat pump (10), which also functions as a condenser, is connected via connecting lines (18, 19) to at least one decentralized flow and temperature control station (20) located in the usage unit (2), so that energy recovered from the exhaust air can be transferred to the decentralized flow and temperature control station (20). The decentralized flow and temperature control station (20) is connected by its supply and return lines to a central buffer storage tank (34) assigned to the entire building. A suitable water temperature control device is also specified.

Description

[0001] The invention relates to a system for water temperature control of a usage unit according to the preamble of claim 1 and a water temperature control device for use in a usage unit of a building.

[0002] In the following, a unit of use is understood to be a self-contained sequence of habitable rooms available for use by one person or a group of people. This can include, for example, self-contained apartments, granny flats, offices, medical practices, commercial units, or similar units within a building, such as an apartment building.

[0003] DE 44 37 845 A1 discloses a system for air conditioning at least one unit, preferably a house, wherein the unit includes at least one exhaust air device of a ventilation system. A controllable exhaust air damper is arranged on the exhaust air device, and the exhaust air is conveyed downwards within an exhaust air duct by an extraction device into a heating center, where it is fed to a heat pump for energy recovery. This heat pump contributes at least partially to the domestic hot water supply for the unit, with the main energy being supplied by various heat sources, e.g., a heat pump, a pellet boiler, or other renewable energy sources. This heated water is then supplied to the consumers via mixing valves and solenoid valves by means of circulation pumps.

[0004] In the following, "consumer" refers to a heating system, preferably underfloor heating, and / or fittings that provide heated water.

[0005] 99% of all newly constructed multi-story residential buildings are equipped with a ventilation system to ensure minimum air exchange. However, approximately 70% (estimated) of these systems do not have heat recovery, as systems with supply and exhaust air and heat recovery are very expensive. However, legislation is slated to mandate heat recovery in the near future, creating a need for a cost-effective technical solution.

[0006] While a generic system for water temperature control in a residential unit is known from DE 10 2021 107 698 A1, this patent application concerns the use of district heating. Furthermore, DE 10 2021 107 698 A1 discloses a heat exchanger used to heat the refrigerant. In addition, according to this document, the heat provided by the heat pump is transferred to a hot water storage tank in the residential unit. Therefore, a cost-effective technical solution remains a requirement.

[0007] The invention is based on the objective of providing a system for water temperature control in a utility unit, using known energy sources, in order to ensure high and economical energy efficiency. Furthermore, a suitable water temperature control device for this purpose is to be specified.

[0008] The problem is solved according to the invention by the features of the independent claims, while advantageous embodiments and further developments of the invention can be found in the dependent claims.

[0009] An advantageous feature is that, in multiple units, the exhaust air from each unit can be discharged into the building's ambient air via an exhaust air device and a decentralized air duct through an exterior wall. Furthermore, a decentralized heat pump, assigned to each unit, is connected to this exhaust air device. A heat exchanger within the decentralized heat pump, acting as a condenser, is connected via connecting lines to at least one decentralized flow and temperature control station located within the unit. This allows the energy recovered from the exhaust air by the heat pump to be transferred to the decentralized flow and temperature control station. The decentralized flow and temperature control station is connected via its supply and return lines to a central storage tank, particularly a buffer tank, located throughout the entire building.

[0010] In the following, water temperature control refers to both the heating and cooling of water, such as domestic water, fresh water, heating fluid or the like.

[0011] The connection between the decentralized flow and temperature control station and the central storage tank can be achieved via a liquid-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 respective unit. Additional decentralized flow and temperature control stations for other units within the building can also be connected to the central supply and / or return line.

[0012] The system according to the invention advantageously integrates 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 known solutions, a more energy-efficient system is thus provided. Furthermore, due to the system's modularity and simple design, installation and maintenance costs are reduced.

[0013] Instead of a large and centrally located heat pump or a cross-flow heat exchanger, small heat pumps are used in the exhaust air devices of the individual user units.

[0014] The heat pump used is very compact and can, for example, be integrated into a ventilation duct. However, it is preferable to install the heat pump together with the flow and temperature control station in a shared cabinet or rack. This allows the heat pump to be installed in a space-saving manner within a single unit, hydraulically integrated into the heating system, and capable of heating the required water to the necessary temperature.

[0015] The building technology 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 makes it possible to operate the heat pumps with high efficiency even with different volume flows and different amounts of heat that can be recuperated from the waste heat.

[0016] The exhaust air volume flow rates and the heating and / or hot water requirements determine the volume flow rate of the micro heat pump. In this document, 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.

[0017] Fresh air is supplied via external air inlets, and humidity-controlled air extraction is achieved via a central fan on the roof, as described in an unrelated explanatory note. This central exhaust system reduces the number of components required for exhaust air extraction. It also simplifies control and enables more efficient operation of the components. Consequently, centralized air extraction via a central main air duct is more energy-efficient and cost-effective overall than decentralized exhaust systems.

[0018] The system according to the invention thus combines the advantages of a decentralized exhaust air system, in which the exhaust air is discharged from the usage unit through a building exterior wall to the ambient air of the building by means of a decentralized air duct, with decentralized heat recovery by means of micro heat pumps in the usage units.

[0019] The removal of exhaust air via a central main air duct, as described in the preceding explanatory section, has beneficial effects on fire protection in the building.

[0020] When several decentralized units are connected to a central supply and / or exhaust air system and thus interconnected via airflow, the uncontrolled spread of fires and exhaust gases across multiple units via the central supply or exhaust air system must be prevented. For this purpose, fire protection devices must be installed in the supply and exhaust air systems of the respective units. This increases the effort required to ensure compliant building fire protection.

[0021] If the supply air is provided decentrally in each unit via supply air devices, while the exhaust air is extracted via a central exhaust system with a main air duct, only the exhaust air devices of the individual units are connected via the central exhaust duct system. The associated fire protection requirements are comparatively low. Consequently, the advantages of a central exhaust system can be utilized without incurring significant disadvantages. At the same time, with a decentralized supply air system, so-called ceiling firestops can be advantageously used as fire protection devices. Compared to fire dampers, which would be required with a central supply air system, these require less maintenance, are simpler in design, and are less expensive to procure.

[0022] In addition to being discharged via a central main air duct, exhaust air can be discharged decentrally from a unit, preferably through an exterior wall of the building, for example, into the building's ambient air. For this purpose, a suitable exhaust device, such as a fan, can be connected to an exterior wall of the 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 lower in this case.

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

[0024] Alternatively or additionally, an exhaust air device, such as a fan, can be positioned at a distance from the heat pump and connected to it via an air duct, for example, in a wall separating a bathroom from other rooms. In this case, the exhaust air from the unit is forced by the exhaust air device towards the heat pump, where it passes through a heat exchanger and is then released, for example, into the surroundings of the unit or the building.

[0025] The operating principle of a heat pump is based on a closed heating system, whereby the heat pump extracts energy from the exhaust air and makes it usable for the heating system. To do this, it uses electrical energy to raise the extracted ambient energy to the required temperature level and transfers the heat to at least one consumer, preferably an underfloor heating system. The thermal energy is thus transferred to the floor via the underfloor heating pipes, thereby heating the living space.

[0026] As heat is transferred to the user unit, the temperature of the heating water decreases, which flows back within the heating circuit and is reheated through energy exchange with the refrigerant of the heat pump.

[0027] The amount of available heat energy in the exhaust air depends on the size of the unit. For example, approximately 10 W of heat can be recovered per square meter of living space; for a living space of 50 m² or less, this increases to 500 W, and for 150 m² or less, it rises to 1,500 W, which is theoretically available as heat energy.

[0028] To optimally utilize the heat pump, a flow and temperature control station is integrated into the water temperature control system of a usage unit, which is energetically coupled with the heat pump, the central heating plant and the consumers.

[0029] 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 in the heat exchanger from the refrigerant of the heat pump to the fluid in the connecting lines and then transferred to the central flow and temperature control station. Preferably, the flow and temperature control station is hydraulically connected to the heat exchanger of the heat pump, which also functions as a condenser. In this case, the transfer of thermal energy to the fluid flowing to and from the flow and temperature control station causes the refrigerant of the heat pump to transition at least partially from a gaseous to a liquid state, resulting in a particularly simple heat pump design.

[0030] The heat pump is energetically connected to the heating plant via pipes, which includes at least one heat source and a storage tank. The heat pump and the heating plant are energetically, and preferably also hydraulically (i.e., via fluid flow), connected to the flow and temperature control station, which regulates the supply of the heated 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 plant.

[0031] By directly integrating the heat pump hydraulically into the heating system, the thermal energy recovered from the exhaust air by the heat pump can be supplied directly to the flow and temperature control station of the usage unit, from where the thermal energy is distributed to the heating circuit of the usage unit or to other thermal consumers of the usage unit.

[0032] 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 tank via the flow and temperature control station. This eliminates the need for a decentralized buffer storage tank for thermal energy storage, particularly in the unit or the heat pump itself.

[0033] The building's central buffer storage tank can therefore preferably be connected to each of the provided decentralized flow and temperature control stations via a supply line and a return line, respectively, so that the excess thermal energy recovered from the exhaust air in the individual decentralized usage units can be stored in the shared, central buffer storage tank.

[0034] In tall buildings, such as high-rises with multiple floors, fluid-carrying pipes can be subjected to high pressures. To counteract this, the central buffer storage system can have several storage reservoirs distributed throughout the building's height. Each storage reservoir can be assigned to different building units, with the reservoirs located at varying heights. This reduces the pressure differential that must be bridged in the central supply and return lines between the respective central storage reservoir and the associated decentralized flow and temperature control stations of the building units. This is particularly advantageous in multi-story buildings, such as high-rises, because the pumps used to circulate the water can be smaller.

[0035] Thus, the energy generated by the heat pump that is not directly supplied to the unit of use 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 tanks in the unit of use, less space is required when using a system according to the invention. The space available in a unit of use can therefore be used for other purposes. Due to the small space requirement, it is also possible to easily retrofit the system for water temperature control in existing buildings.

[0036] The central storage unit in the system is used, for example, to cover peak loads. This storage unit is preferably a stratified storage unit, but can also be a buffer storage unit.

[0037] By using the heat pump and storage system, the primary energy source, e.g. a boiler, a central heat pump or a gas condensing boiler, can be made smaller, for example by about 33-50% compared to conventionally used boilers.

[0038] The heat recovery system created by means of the heat pump can, for example, provide the base load supply, which significantly reduces the size of the central primary heat source, as it then only covers the remaining heat demand, especially the thermal peak loads.

[0039] A particular advantage is that, especially in passive houses, i.e. houses in which the majority of the heating demand 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.

[0040] The term "spread" in 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.

[0041] The heat pump utilizes the ambient heat from the exhaust air by using it to evaporate a refrigerant, which is then compressed by a compressor to raise its temperature. It operates particularly efficiently with a low flow temperature in the heating circuit. This reduces the strain on the compressor, thus lowering electricity consumption.

[0042] In this system, the room air serves as the heat source for the decentralized heat pump in the individual units. The heat pump can then supply the heating system and, additionally or alternatively, the decentralized hot water supply.

[0043] Control and regulation of the system is accomplished 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.

[0044] For this purpose, the decentralized flow and temperature control station can be hydraulically connected via pipes to the heat pump located 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, and to a central thermal storage unit of the building.

[0045] The decentralized flow and temperature control station can have various valves by which the flow of heat transfer fluid, in particular water, to / from the heat pump, to / from the central thermal storage tank, and to / from the consumers of the building unit can be controlled. For example, excess thermal energy provided by the heat pump that is not used for heating in the building unit can be used to raise the temperature of a central return line of the building by means of appropriate valve configuration in the decentralized flow and temperature control station, and thus be transferred to the building's central buffer storage tank.

[0046] A sophisticated control system regulates the decentralized heat pump and the ventilation system of a given unit according to demand. This can be done in a modulating manner and, if required, 24 hours a day, 7 days a week.

[0047] The heat pump uses electrical energy to raise the thermal energy of the exhaust air to a higher temperature level. This creates a significant surplus of heating energy. The lower the required temperature, the less energy the heat pump needs to expend. The heat pump can be powered decentrally or centrally. It is controlled by a controller, which is installed, for example, in the heat pump, ventilation system, apartment station, or building management system. Control can also be decentralized or centralized.

[0048] The coefficient of power, or COP for short, is the ratio of generated heat or cooling power to the electrical power input.

[0049] The COP value is used below in relation to a heat pump with a smaller temperature difference, where the decisive factor is the air volume in combination with the heat pump's COP values. The heat pump achieves an optimal COP at heating temperature. Generally, the heat pump provides the heating temperature required. This is controlled by the flow and temperature control station and monitored by at least one sensor.

[0050] In one exemplary embodiment, each user unit has its own adjustable flow and temperature control station, which controls 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.

[0051] Hot water can be supplied centrally or decentrally via heat pumps in the individual units. If insufficient energy is available, the desired temperature is reached via an instantaneous water heater.

[0052] 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.

[0053] The flow and temperature control station supplies the heated water to the consumers via circulation pumps, mixers, and solenoid valves.

[0054] The flow and temperature control station is coupled to the buffer storage tank and / or domestic hot water storage tank, which provides and / or stores heated water.

[0055] Excess heat from the heat pump can be diverted to the buffer storage tank of the heating plant to be available as a heat source for peak loads in the usage unit.

[0056] All flow and temperature control stations in the building can communicate with each other and transmit values ​​to a main controller, which is preferably located in the heating plant. This can be done via IoT, radio, or wired connection.

[0057] The valves and turbines that provide the flow rate are controlled by a separate control system. This system determines whether the decentralized heat pump directly supplies the heating system or whether the return temperature is raised for the central storage tank. The requirements are set via return temperature controllers and temperature controllers in the flow and temperature control station.

[0058] A weather-compensated control system can regulate system temperatures based on the optimal COP value. The control system balances all available energy sources, i.e., heat pump and / or heat source and / or buffer storage, to achieve the highest efficiency.

[0059] Each unit has at least one, preferably two, heat meters that record the energy supplied, generated, and consumed. Users also benefit from this system, as excess heat energy can be stored in the central storage tank, thereby reducing utility costs.

[0060] The energy recovered by the decentralized heat pump can be recorded separately for each assigned unit within a building. For example, the portion of the energy recovered by the heat pump that is consumed locally within the unit can be recorded separately from the portion of the recovered energy that is supplied to a central buffer storage tank in the building.

[0061] The recorded energy quantities can be assigned a monetary value. Based on this, for example, the utility costs of tenants in a unit can be reduced if energy recovered by a decentralized heat pump assigned to that unit is fed into a central buffer storage tank in the building. Such recording of yields, broken down by unit, is particularly advantageous when some units in a building are equipped with water temperature control systems for heat recovery, while other units in the building do not have such systems.

[0062] Operating with a decentralized heat pump offers another advantage. It can be used not only for heating but also for cooling or temperature control, as reversible operation is possible. In this mode, cold water flows through the underfloor heating pipes. It warms up and thus absorbs 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. The pump extracts the thermal energy from the return water and releases it to the environment outside the unit via the exhaust air. This cools the water again before it flows through the underfloor heating system once more.

[0063] The following describes the individual operating modes of the system in conjunction with underfloor heating, which acts as the consumer, using various examples. This list is not exhaustive. The first and second valves of the flow and temperature control station are mixing valves, preferably control valves with pulse input. The heat pump in the examples delivers a constant output of 1,500 watts. The temperature and water volume supplied to the heating system are controlled as needed by the flow and temperature control station by switching the first and second valves accordingly. Control is thus achieved via a turbine controller with volumetric flow measurement and control valves, in particular the first and second valves, which open and close as required.

[0064] A consistent flow rate without temperature fluctuations is achieved. Any excess energy from the heat pump is fed back into the system via the return flow (return temperature boost).

[0065] A heat meter, which can operate in two directions, for example, runs backwards, thus directly reducing the measured energy consumption at the user's location. This can potentially also be achieved using two integrated heat meters by comparing the differences in heat meter readings and thus demonstrating the overall efficiency. Winter full load:

[0066] When the underfloor heating is set to full capacity in winter, its heat demand exceeds the heat pump's output. For example, the heating load required for a unit of 150 m² is 4,500 W. However, the heat pump can only supply 1,500 W.

[0067] Since more energy is required than can be supplied by the decentralized heat pump, the remaining amount of heat required is requested from the heating plant by the flow and temperature control station, resulting in the following volume flows.

[0068] In this case (full load), the underfloor heating requires 773 l / h. The decentralized heat pump provides a flow rate of 258 l / h with a 5 K temperature difference. This flow rate is heated in the heat pump and used directly in the unit (circulation). The remaining energy required to meet the unit's heating demand, in this case 515 l / h, comes from the central heating plant.

[0069] Thus, the volume flows of the heat pump (258 l / h) and the heating plant (515 l / h) are combined via a valve in the flow and temperature control station.

[0070] The flow rates are divided again via another valve of the flow and temperature control station after return from the underfloor heating, 258 l / h to the heat pump and 515 l / h to the heating center. Winter - Part load I:

[0071] In this example, the heating demand is lower than the heat pump's output. For instance, a heating load of 1,353 W is assumed for 150 m², which 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.

[0072] The decentralized heat pump delivers a flow rate of 258 l / h at a 5 K temperature difference. This flow rate is heated within the heat pump. A portion is used directly in the unit (partial circuit). The underfloor heating requires a partial load flow rate of 200 l / h. Therefore, the first valve of the flow and temperature control station releases the heat pump's flow rate of 200 l / h. 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 line to the central buffer tank. Summer operation I:

[0073] The heating system's heat demand is lower than the heat pump's output; in particular, in the example case shown, there is no need to operate the heating system due to warm outside temperatures.

[0074] All the energy from the decentralized heat pump is transferred via the central return line to the central buffer tank in the building's basement by means of a corresponding switching of the first and second valves of the flow and temperature control station. The existing control system allows the tank to be maintained at a specific temperature, for example, 40°C. This means that, depending on the heat demand, a temperature of 40°C can be supplied from the buffer tank without intervention from the primary heat generator in the basement. The remaining temperature required for the desired hot water is increased by the instantaneous water heater of the flow and temperature control station. The decentralized heat pump operates with a very high COP (coefficient of performance).

[0075] The decentralized heat pump delivers a flow rate of 258 l / h at a temperature difference of 5 K. This flow rate is heated in the heat pump and transferred directly to the heating plant, increasing the return temperature of the central return flow to the buffer storage tank. Summer operation II: (Temperature control)

[0076] The decentralized heat pump delivers a flow rate of 258 l / h at a 5 K temperature difference. This flow rate is cooled within the heat pump and, through appropriate control of the valves in the flow and temperature control station, is made available directly in the apartment. In this case, 258 l / h. Summer operation III:

[0077] 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.

[0078] 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 supplied to the central storage tank. From this tank, 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, such as a boiler or a central heat pump in a heating plant, is not needed in summer.

[0079] Furthermore, a water temperature control device for use in a building's residential unit is provided. The water temperature control device according to the invention can, for example, be used in new construction projects for water temperature control in residential 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 residential units in a building to be equipped with the water temperature control device. Rather, due to the flexible application and standardized connections of the water temperature control device, a decision can be made individually for each residential unit as to whether the water temperature control device should be used.

[0080] A water temperature control device comprises at least one heat pump to which exhaust air from an exhaust air device of the user 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 constitutes the condenser of the heat pump.

[0081] Consequently, energy recovered from the exhaust air by means of 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 refrigerant of the heat pump to water in the connecting lines.

[0082] The decentralized flow and temperature control station provides various connections for integrating the water temperature control device into a water temperature control system: Firstly, the decentralized flow and temperature control station can be connected via a fluid line to a central buffer storage tank shared by the entire building, in particular via a central supply and / or return line leading from the buffer storage tank to the unit where the water temperature control device is installed. Furthermore, the decentralized flow and temperature control station can be connected to at least one consumer within the unit, in particular an underfloor heating system, so that a temperature-controlled quantity of water can be supplied to the consumer(s) of the unit via the flow and temperature control station, which serves as the interface.

[0083] Preferably, the heat pump and the flow and temperature control station, i.e., the entire water temperature control device, are arranged in a single mounting unit, in particular a rack, frame, cabinet, or the like. This design makes the water temperature control device particularly space-saving, which brings with it the advantages described above. Furthermore, the water temperature control device is easily transportable in this way. It can also be pre-assembled so that it can be delivered to a construction site ready for installation.

[0084] By means of the flow and temperature control station, water from the building's central buffer storage tank can be mixed with water that has flowed through the heat exchanger of the heat pump and supplied to at least one consumer of the usage unit.

[0085] The flow and temperature control station can have at least one first valve for mixing the flow rates from the decentralized heat pump and the central buffer storage tank, wherein the mixed flow rate can be supplied to at least one consumer in the unit. The flow and temperature control station can have a second valve for splitting the flow rate returning from the at least one consumer in the unit into flow rates to the decentralized heat pump and the central buffer storage tank.

[0086] By combining the flow and temperature control station and the heat pump, the heat pump can be optimally utilized, as the energy can be stored centrally, saving space and costs.

[0087] The required domestic hot water and heating temperatures can be controlled depending on the PV yield, in order to always achieve an optimal efficiency of all energy system components.

[0088] The subject matter of the present invention is not only derived from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another.

[0089] In particular, statements made in connection with the water temperature control system of a usage unit should also be applicable to a water temperature control device, and vice versa.

[0090] All information and features disclosed in the documents, including the abstract, and in particular the spatial configuration shown in the drawings, could be claimed as essential to the invention, insofar as they are novel individually or in combination compared to the prior art. The use of the terms "essential," "according to the invention," or "essential to the invention" is subjective and does not imply that the features so designated must necessarily be part of one or more patent claims.

[0091] The invention is explained in more detail below with reference to drawings illustrating only one embodiment. Further essential features and advantages of the invention will become apparent from the drawings and their description.

[0092] They show: Figure 1: Schematic view of a state-of-the-art heat pump; Figure 2: Schematic view showing several decentralized heat pumps for different usage units; Figure 3: A functional diagram of the connection between the heat pump and the station; Figure 4: A functional diagram of the system for water temperature control of at least one usage unit; Figure 5: Block diagram for winter full-load operation; Figure 6: Block diagram for winter part-load operation; Figure 7: Block diagram for summer operation with underfloor heating; and Figure 8: Block diagram for summer operation with storage tank filling.

[0093] Figure 1Figure 1 shows an example from the state of the art. The exhaust air from a usage unit 2 flows into the exhaust air device 4, which is installed in the floor slab 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 by means of built-in fans. Thus, heat energy recovery can take place based on the heat energy present in the exhaust air.

[0094] The heat energy thus recovered can be supplied to an air-to-water heat pump, which in the example shown consists of a 10" indoor unit and a 10" outdoor unit. The 10" + 10" air-to-water heat pump can therefore be supported with the heat energy recovered from the exhaust air, for example to temper the water for the heating system.

[0095] Figure 2Figure 1 shows a building with several units 2. Each unit 2 is supplied with fresh air via a decentralized supply air device 3, which then leaves 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 transfers its heat energy via this heat pump 10 before being guided through the supply line 5 into a main air duct 6 within the service shaft. This vertically running main air duct 6 terminates in a roof box 8 before finally exiting the building into the surrounding environment via a central air outlet 9.

[0096] The main air duct 6 also receives the supply lines 5 of the other usage units 2, with each usage unit 2 having a heat pump 10 in its exhaust air device 4.

[0097] The arrangement described here, which provides for a decentralized supply of fresh air via the supply air devices 3 and a central exhaust air discharge 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 units 2 are connected to a central exhaust air system and thus interconnected, the uncontrolled spread of fires and exhaust gases via the central exhaust air system across multiple 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 and 4 of the respective units 2.

[0098] If the supply and exhaust air are provided via a central system, fire dampers are often required as fire protection devices. These dampers are complex in design and require intensive maintenance. Therefore, the installation and operation of fire dampers are expensive.

[0099] If, however, as in the illustrated embodiment, the supply air is provided decentrally in the respective usage unit 2 via supply air devices 3, but a central exhaust air system with a main air duct 6 is simultaneously present, only the exhaust air devices 4 of the usage 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 in design, and are less expensive to procure. At the same time, however, the advantages of a central exhaust air system described above are achieved.

[0100] Figure 3 shows a functional representation of the linkage of a decentralized heat pump 10 with a decentralized flow and temperature control station 20.

[0101] 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 connected via connecting lines to a heat exchanger 47 of the heat pump 10. The heat pump 10 is connected via connecting line 18 to the return line of an underfloor heating system and via connecting line 19 to the supply line of the underfloor heating system 30, and is thus integrated into the heating circuit.

[0102] The exhaust air is preferably drawn into the heat pump 10 via a fan (not shown), where the heat energy is extracted from the exhaust air.

[0103] In the heat pump 10, the energy is passed by 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.

[0104] In the evaporator 11 of the first heat exchanger 46, the refrigerant transitions into a gaseous state even at low temperatures and is fed to the compressor 13. The compressor 13, which is electrically driven, increases the pressure in the gas, causing it to heat up considerably.

[0105] Electrical energy is required to operate the compressor 13, which is also converted into heat energy.

[0106] The heated and gaseous refrigerant is directed to the second heat exchanger 47 and there releases the heat energy to the heating water of the heating circuit 17.

[0107] In this process, the refrigerant in the condenser 12 of the second heat exchanger 47 liquefies again and the high pressure drops. The remaining pressure is then released in an expansion valve 14.

[0108] The refrigerant, now liquid again, returns to the first heat exchanger 46 or evaporator 11 and absorbs heat energy again from the exhaust air of a usage unit 2.

[0109] In Figure 4 The system for water temperature control in unit 2 is shown in simplified form. The heat pump 10 produces heat from the exhaust air of unit 2 and transfers it to the heating water of the underfloor heating system 30 in unit 2. The cooled exhaust air flows into the building's surroundings via the air outlet 9.

[0110] The cooled heating water from the return line of the underfloor heating 30 is directed via the connecting line 18 to the heat exchanger 47 of the heat pump 10 and, as heating circuit 17, absorbs the heat energy of the refrigerant and flows back via the connecting line 19 into the supply line of the underfloor heating 30.

[0111] If the energy supplied by heat pump 10 is insufficient to meet the heating demand of heating system 30 in unit 2, flow and temperature control station 20 can add further heated water from the central heating plant 32. The combination of centralized and decentralized heat supply makes system 1 flexible and expandable. Furthermore, system 1 is particularly energy-efficient due to the recovery of thermal energy contained in the exhaust air and the demand-dependent control of the flow and temperature control station.

[0112] The boiler 35, located in the heating plant 32, heats the water that is drawn from the buffer storage tank 34 and routed via the flow line 28 to the flow and temperature control station 20. There, it is mixed with the water heated by the heat pump 10 via a valve 37 and then directed into the underfloor heating system 30. After passing through the underfloor heating system, this flow is divided again via a second valve 38 of the flow and temperature control station 20. For example, part of the flow goes to the heat pump 10, and part is returned to the heating plant 32, specifically to the buffer storage tank 34, via the central return line 29. The flow rates into and out of the heating plant are measured by the measuring station 33 in the heating plant 32, which transmits its values ​​to the flow and temperature control station 20, specifically to a control unit 21 of the flow and temperature control station 20.

[0113] 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 tank 34 via the central return 29 and is available there, for example, for consumers 31', 31" and 31‴.

[0114] Consumer 31' is a shower that draws its hot water from buffer storage tank 34. The flow and temperature control station 20 regulates the supply of heated water, which, after passing through station 20, flows to consumer 31' via hot water line 27.

[0115] Consumer 31‴, which is formed by a toilet, only requires drinking water, which is supplied via the drinking water line 26 from station 20, which controls the flow of the drinking water line 26.

[0116] Depending on the temperature level prevailing in the buffer storage tank 34, the thermal energy stored in the buffer storage tank 34 can therefore be used to support the heating of a usage unit 2 or to prepare hot water for a usage unit 2.

[0117] The Figures 5 to 7 Figure 1 shows various applications of system 1 for water temperature control of at least one usage unit 2. The heat pump 10 transfers the generated heat to the water in the heating circuit 17 via a heat exchanger 47, represented by the flow pipe 42 of the heat pump.

[0118] A circulation pump (not shown) continuously moves the water in a closed circuit through the piping of the underfloor heating system 30 and the heat exchanger 47 of the heat pump. In this example, the flow rate is the amount of water that flows through the heat exchanger in a specific unit of time. It is usually expressed in liters per hour (l / h). However, the term volumetric flow rate, which is more commonly used in technical circles, will be used here instead of flow rate.

[0119] Thus, in the examples, according to the Figures 5 to 7 Assuming a volume flow rate of 258 l / h passing through the heat exchanger 47 of the heat pump 10, and a temperature difference of 5 Kelvin, the calculation is based on this assumption.

[0120] System 1 includes a heat exchanger 41 for domestic hot water preparation, which can be located, in particular, in the flow and temperature control station 20. The heat exchanger 41 for domestic hot water preparation is connected via pipes to the fluid circuit through which the heat pump 10 flows. A hot water valve 39 can establish or interrupt a fluid connection between the heat exchanger 41 and the supply and return lines 42, 43 of the heat pump 10 or the supply and return lines 44, 45 of the underfloor heating 30. In this way, excess thermal energy supplied by the heat pump 10 can be used for domestic hot water preparation.

[0121] In Figure 5 This flow rate is thus heated in heat pump 10 and used directly for heating unit 2 (circuit). In this winter example, the underfloor heating system 30 runs at full load and requires a flow rate of 773 l / h via return line 45.

[0122] 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 storage tank 34 are mixed via the valve 37 and supplied to the underfloor heating 30 via the return 45.

[0123] The missing energy for the heat requirement of the underfloor heating 30, in this case 515 l / h, thus comes via the flow pipe 28 from the heating center 32, since the heat generation of the heat pump 10 is insufficient.

[0124] After passing through the underfloor heating 30, the volume flows are again divided via the valve 38, whereby 258 l / h are again directed via the decentralized return 43 to the heat pump 10 and the remaining 515 l / h are directed via the central return 29 to the heating center 32.

[0125] The volume flows, in particular the valves 37, 38, are controlled via the control unit 21 of the flow and temperature control station 20.

[0126] Taking into account a temperature difference of 5K, in the example shown the volume flow of 515 l / h can also be interpreted as 3000W and the volume flow of 258 l / h as 1500 W for a 773 l / h or 4500 W requirement of the underfloor heating 30.

[0127] The volume flow of the return flow 43 is measured via a turbine 36.

[0128] Figure 6Figure 1 shows an application example for winter partial load operation. The decentralized heat pump 10 delivers a flow rate of 258 l / h at a temperature difference of 5 K. This flow rate is heated in the heat pump 10, and a portion is used directly in the utilization unit 2 (partial circuit). The excess flow rate is discharged into the heating center 32, thereby increasing the return temperature of the central return line 29, in this case by the flow rate of 108 l / h.

[0129] The underfloor heating system 30 requires a flow rate of 150 l / h in this partial load case. Therefore, the flow rate of 150 l / h from the supply line 42 of the heat pump 10 is released via the valve 37, and the excess 108 l / h of the flow rate from the heat pump 10 flows via the return line 29 into the heating center 32 and is stored there in the buffer tank 34.

[0130] After leaving the underfloor heating 30, the volume flow of 150l / h flows as supply to the valve 38, where this volume flow is mixed with a volume flow of 108l / h and returns to the heat pump 10 via the return 43 as a volume flow of 258l / h.

[0131] Taking into account a temperature difference of 5K, in the example shown the volume flow of 108 l / h can also be interpreted as 628W and the volume flow of 258 l / h as 1500 W for a 150 l / h or 872 W requirement of the underfloor heating 30.

[0132] Figure 7Figure 1 shows an application example for summer operation, where the underfloor heating system 30 is heated. The decentralized heat pump 10 delivers a flow rate of 258 l / h at a temperature difference of 5 K. This flow rate is cooled in the heat pump 10 and used directly in the operating unit 2 (circulation). There is no excess flow rate that is discharged to the heating unit 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.

[0133] In this case, the underfloor heating system 30 requires a flow rate of 258 l / h. Therefore, the flow rate of 258 l / h from the supply line 42 of the heat pump 10 is released via valve 37.

[0134] After leaving the underfloor heating 30, the volume flow of 258l / h flows as supply 44 to the valve 38, where the volume flow of 258l / h returns to the heat pump 10 via the return 43.

[0135] Taking into account a temperature difference of 5K, the volume flow rate of 258 l / h in the example shown can also be interpreted as 1500W.

[0136] Figure 8 The diagram shows a summer operating mode, in which the energy generated by the heat pump 10 is transferred to the central buffer storage tank 34 in the heating plant 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 can be, for example, 40°C. This means that, depending on the heat demand, e.g., 40°C hot water can be supplied from the buffer storage tank 34 without intervention from the boiler as the primary heat energy generator.

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

[0138] Thus, the decentralized heat pump 10 delivers a flow rate of 258 l / h at a temperature difference of 5 K. This flow rate is heated in the heat pump and transferred directly to the heating unit 32 via the flow pipe 42 and the return pipe 29, i.e., the return temperature is increased. In this case, with a flow rate of 258 l / h.

[0139] The underfloor heating system 30 has no demand. Valve 37 opens the path to the heat pump 10, and the entire flow rate of 258 l / h is introduced via the return line 43. The flow rate is measured by turbine 36. Valve 38 is closed. Taking into account a temperature difference of 5 K, the flow rate of 258 l / h can be interpreted as 1500 W in the example shown. Reference symbol list

[0140] 1 System 2 Usage unit 3 Supply air device 4 Exhaust air device 5 Supply line 6 Main air line 7 Supply shaft 8 Roof box 9 Air outlet 10, 10', 10", 10‴ Heat pump 11 Evaporator 12 Condenser 13 Compressor 14 Expansion valve 15 Refrigerant circuit 16 Flow medium 17 Heating circuit 18 Connecting line 19 Connecting line 20 Flow and temperature control station 21 Control 22 Heat meter 23 Heating circuit manifold 24 Valves (hot water) 25 Valves (cold water) 26 Potable water line 27 Hot water line 28 Heating flow 29 Heating return 30 Underfloor heating 31, 31', 31", 31‴ Consumer 32 Heating center 33 Measuring station 34 Buffer tank 35 Boiler 36 Turbine (1) 37 Valve (4) 38 Valve (5) 39 Hot water valve 40 Bypass flow 41 Heat exchanger (to DHW) 42 Flow (of 10) 43 Return (of 10) 44 Flow (of 30) 45 Return (of 30) 46 Heat exchanger 47 Heat exchanger

Claims

1. System (1) for water temperature control of at least one usage unit (2) or a plurality of usage units (2) of a building, wherein at least one exhaust air device (4) of a ventilation system is provided in the usage unit (2), wherein 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 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 from the usage unit (2) through an exterior wall of the building to the ambient air of the building (1) via the exhaust air device (4) by means of a decentralized air duct, - a decentralized heat pump (10) assigned to the usage unit (2) is connected to the exhaust air device (4) by means of an air duct, - the decentralized heat pump (10) is connected to at least one decentralized flow and temperature control station (20) arranged in the usage unit (2),so that energy recovered from the exhaust air can be transferred to the decentralized flow and temperature control station (20), - and the decentralized flow and temperature control station (20) with its supply and return lines is connected by liquid to a central buffer storage tank (34) assigned to the entire building, , characterized by the fact that - a heat exchanger (47) acting as a condenser (12) of the decentralized heat pump (10) is connected via connecting lines (18, 19) to the at least one decentralized flow and temperature control station (20) arranged in the usage unit (2).

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

3. System according to claim 1 or 2, characterized by the fact thatthe heat pump (10) and the heating center (32) are energetically connected to the flow and temperature control station (20), which regulates 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 by the fact that the consumer is a heating system, in particular a floor heating system (30), whose flow and return are energetically coupled to the heat pump (10).

5. System according to any one of claims 1 to 4, characterized by the fact that that the water passing 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 any one of claims 1 to 5, characterized by the fact that that the water flowing through the flow and temperature control station (20) can be additionally heated by a flow heater located in the flow and temperature control station (20).

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

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

9. System according to any one of claims 1 to 8, characterized by the fact 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 tank (34) of the heating center (36).

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

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

12. System (1) according to any one of claims 1 to 11, characterized by the fact that The required domestic hot water and heating temperatures can be controlled depending on the PV yield, thus ensuring optimal efficiency of all energy system components.

13. Water tempering device for use in a system according to at least one of claims 1 to 12 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) can be connected via a fluid-conducting connection to a central buffer storage tank (34) assigned to the entire building, and wherein the decentralized flow and temperature control station (20) can be connected to at least one consumer (30, 31, 31", 31") of the usage unit (2) for supplying a tempered quantity of water. characterized by the fact that 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) which acts as a condenser, so that energy recovered from the exhaust air by means of the decentralized heat pump (10) can be transferred to the decentralized flow and temperature control station (20).

14. Water temperature control device according to claim 13, characterized by the fact that the decentralized heat pump (10) and the decentralized flow and temperature control station (20) are arranged in a common mounting unit, in particular a rack, frame, cabinet or the like.

15. System (1) according to claim 1 or water temperature control device according to claim 13 or 14, characterized by the fact thatby means of the decentralized flow and temperature control station (20) water from the central buffer storage 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 supplied to at least one consumer (30, 31, 31", 31") of the usage unit (2).

16. Water temperature control device according to one of claims 13 to 15, characterized by at least one of the features of claims 2 to 12.

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