Heat supply system, multi-family dwelling, and methods for operating a heat supply system

Abstract

The invention relates to a heat supply system (100) comprising a heat source (101) and a plurality of heat sinks (301-306), wherein the heat source (101) and the plurality of heat sinks (301-306) are coupled via a common heat circuit (200), wherein heat at a first temperature level can be transported from the heat source (101) to the plurality of heat sinks (301-306) via a supply line (201) of the common heat circuit (200) and can be transported back via a return line (202) at a second temperature level reduced compared to the first temperature level, and wherein the plurality of heat sinks (301-306) is configured as a plurality of second heat pumps (301-306).The heat supply system (100) according to the invention is characterized in that each of the second heat pumps (301-306) is connected to the heat source (101) at the communication level, so that heat requests from each of the second heat pumps (301-306) can be transmitted to the heat source (101) and that the heat source (101) is configured to maintain the first temperature level constant by means of the heat requests. The invention further relates to a method for operating a heat supply system (100).

Description

[0001] The invention relates to a heat supply system according to the preamble of claim 1, a multi-family dwelling according to the preamble of claim 12, and a method for operating a heat supply system according to the preamble of claim 14.

[0002] Heat pumps are a well-known technology. A heat pump is essentially a heat engine that, by supplying energy, absorbs heat from a lower-temperature reservoir and transfers it to a higher-temperature reservoir. Conversely, a heat pump can also be used for cooling by extracting heat from the system to be cooled – again by supplying energy – and releasing it, for example, to the environment.

[0003] Heat pumps are used in state-of-the-art technology, among other things, for the efficient heating of buildings or for the provision of hot water.

[0004] When a heat pump is used for heating in a multi-family building with several residential units, the refrigerant circuit of the heat pump is usually located in the basement, where an oil, gas, or pellet heating system would typically be located. The residential units are then supplied with heat and hot water via the flow and return pipes of a heating circuit and a domestic hot water pipe. Heat losses occur along the way from the heat pump to the point of use.

[0005] Furthermore, two-stage heat pump systems are also known for multi-family residential buildings, in which a first, comparatively powerful heat pump raises a first heating circuit to a specific temperature by absorbing and transferring ambient heat. The first heat pump and the first heating circuit can be assigned to the multi-family residential building with all the residential units within it.

[0006] A number of secondary heat pumps are connected to this first heating circuit, each assigned to a single apartment in the multi-family building and individually controllable. These secondary heat pumps extract heat from the first heating circuit, thus raising the room temperature in their respective apartments to the desired temperature set by the resident.

[0007] In this context, WO2019 / 220303 A1 describes a heating and cooling system consisting of at least one heat pump and a piping system. A heat transfer fluid can be conveyed via the piping system from a return line of a district heating network to the heat pump, from which the heat pump extracts heat and uses it to heat a liquid storage tank in a building.

[0008] From EP 2 322 880 B1, a heat pump system is known that can heat several residential units in a building. The heat pump system comprises a single ambient heat source circuit with a brine solution, into which different ambient heat sources can be integrated as heat sources. This single ambient heat source circuit is connected to several refrigerant circuits of structurally separate heat pumps, which are assigned to the individual residential units of the building. Individual ambient heat sources can be deactivated by means of diverter or shut-off valves, thus limiting the heat input into the brine solution. In heat pumps located in the individual residential units of the building where there is no heat demand, the brine flows through the corresponding evaporator without releasing any heat.

[0009] From EP 3 371 517 B1, a heating network for a building is known, comprising several individual heat pumps, each of which is individually connected to a common heat source of the network. Depending on its operating mode, each individual heat pump can extract heat from or supply heat to the heat source. The temperature of the common heat source of the heating network is regularly monitored, and if the temperature deviates from a setpoint, energy is either supplied to the heat source from an energy source or extracted from a heat sink as needed.

[0010] However, the well-known heat pump systems for heating buildings have several disadvantages. Firstly, they are not suitable, or only with great difficulty, for retrofitting in existing multi-family buildings; secondly, they exhibit a sluggish temperature control response, meaning that these systems often operate outside of an efficient operating range.

[0011] It is an object of the present invention to propose an improved heat supply system.

[0012] This problem is solved according to the invention by the heat supply system according to claim 1. Advantageous embodiments and further developments of the invention are described in the dependent claims.

[0013] The invention relates to a heat supply system comprising a heat source and a plurality of heat sinks, wherein the heat source and the plurality of heat sinks are coupled to a heat fluid via a common heat circuit, wherein heat at a first temperature level can be transported from the heat source to the plurality of heat sinks via a supply flow of the common heat circuit, wherein heat at a second temperature level can be transported from the plurality of heat sinks to the heat source via a return flow of the common heat circuit, wherein the second temperature level is reduced compared to the first temperature level, and wherein the plurality of heat sinks is configured as a plurality of second heat pumps.

[0014] A heat supply system is therefore provided, designed to supply heat in a common heat circuit. This system comprises a heat source and a multitude of heat sinks connected via a common heat circuit. The heat source, in the supply line of the common heat circuit, raises a heat transfer fluid to a first temperature level, and this fluid is then conveyed to the heat sinks. The heat sinks can extract the required amount of heat from the heat transfer fluid. This process cools the heat transfer fluid to a second temperature level, which is lower than the first. The cooled heat transfer fluid is then returned to the heat source via the return line of the common heat circuit, where it is raised back to the first temperature level.Thus, heat can be continuously transported from the heat source to the heat sinks via the circulation of the heat fluid in the heating circuit.

[0015] The heat source serves to provide heat in the supply line of the common heating circuit. It can include a variety of heat generators, such as solar collectors, geothermal energy, district heating, one or more heat pumps, or conventional boilers that are heated, for example, by burning oil, gas, pellets, or coal.

[0016] In particular, when several different heat sources are used, these can store the heat fluid they each heat in a common buffer storage tank, which can also be part of the common heating circuit.

[0017] The multiple heat sinks consist of several heat pumps, specifically secondary heat pumps, which are coupled to the heat source via a common heating circuit. These secondary heat pumps are designed to extract heat from the flow, resulting in a return flow with a lower temperature than the flow. The extracted heat can then be used by the secondary heat pumps, for example, for heating and hot water preparation in an apartment.

[0018] The second temperature level therefore depends significantly on the amount of heat extracted from the heat fluid by the second heat pumps.

[0019] Since the second heat pumps extract heat from the common heating circuit, they are heat sinks within the meaning of the invention. Regardless, they can also provide heat in an apartment as described and thus fulfill the function of a heat source for the apartment.

[0020] The heat transfer fluid can be, for example, a brine solution or a refrigerant, particularly R290 or R135. However, the use of water as a heat transfer fluid is also conceivable and preferred. Water as a refrigerant is also known as R718. The heat transfer fluid acts as a carrier for the heat from the heat source to the heat sinks. The residual heat in the heat transfer fluid, not extracted by the heat sinks, is then transported back from the heat sinks to the heat source by the heat transfer fluid.

[0021] Heat pumps are generally known for their high efficiency, as they deliver more heat energy than they consume electrical energy. This results in a reduction of the overall energy consumption of the heating system and contributes to sustainability.

[0022] By using renewable energy sources for heat generation, heat pumps can further reduce the use of fossil fuels and CO2 emissions. For example, the electricity required to operate the second heat pump can be generated at least partially by a photovoltaic system.

[0023] According to the invention, it is now provided that each of the plurality of second heat pumps is connected to the heat source at the communication level, so that heat requirements from each of the plurality of second heat pumps can be transmitted to the heat source and that the heat source is designed to keep the first temperature level constant by means of the heat requirements.

[0024] This offers the initial advantage that each of the second heat pumps can directly communicate the current heat demand of a user operating that particular second heat pump to the heat source. The heat source can then proactively adjust its operating point to the heat demand, preventing temperature fluctuations in the flow of the shared heating circuit. If the heat source did not proactively adjust its operating point to the increased heat demand, the flow temperature would be reduced, at least temporarily, because the heat source would otherwise only be able to provide increased heating output once it could detect the temperature change in the return flow. In this case, the heat source would only be able to adjust its operating point with a delay.Furthermore, since the adjustment of the operating point does not occur abruptly but over a certain period of time, heat fluid would enter the flow of the heating circuit, which has a temperature below the desired first temperature level.

[0025] Such a fluctuation in the flow temperature, i.e., the initial temperature level, would, however, force all secondary heat pumps to adjust their operating point, at least temporarily, thus deviating from the desired, most efficient operating point. This would lead to an overall decrease in the efficiency of the heat supply system. If the heat source subsequently increases the flow temperature to the desired setpoint, the secondary heat pumps would again have to adjust their operating point, resulting in another change in the return temperature, to which the heat source would then have to react. This creates a complex control problem that prevents the heat supply system from operating at its most efficient point for a certain period.

[0026] The invention therefore also differs significantly from the heat network of EP 3 371 517 B1, since the invention enables a predictive adjustment of the operating point of the heat source, which leads to simple and precise control and thus to increased efficiency of the heat supply system.

[0027] Accordingly, another advantage of the invention is that the second heat pumps can always be operated at a comparatively efficient operating point due to the constant first temperature level and do not have to switch to a less favorable operating point due to a changed, lower temperature of the flow.

[0028] Furthermore, the refrigerant used and the initial temperature level can be selected and coordinated to enable the most energy-efficient conversion of the gaseous state to liquid and back again. This leads to further improved energy efficiency and a reduction in operating costs. In addition, the system contributes to environmental protection through the use of renewable energy sources and efficient heat utilization.

[0029] This ability of the heat supply system according to the invention to maintain the first temperature level in the flow line constantly, regardless of the heat extraction by the second heat pumps, is advantageously achieved by appropriately adapted control of the heat source and the heat sinks. The interaction of the heat source with the heat sinks is thus optimized so that fluctuations in heat demand, i.e., in the amount of heat extracted from the flow line by the heat sinks and therefore in the second temperature level, can be immediately compensated for, so that the first temperature level remains constant.

[0030] It is advantageous for the supply line to maintain a constant temperature between 21 °C and 25 °C, particularly advantageous between 22 °C and 24 °C, and most advantageously at 23 °C. Since these temperatures are generally not, or only slightly, above the ambient temperature, in many cases elaborate thermal insulation of the pipes can be dispensed with.

[0031] To meet a situationally increased energy demand from the second heat pump, the flow rate of the heat fluid through the heating circuit can be increased, for example, so that the first temperature level remains unchanged while the amount of heat transported is increased. Only the flow rate of a corresponding circulation pump needs to be increased for this purpose. The flow rate can be automatically adjusted by each second heat pump, particularly via a control unit, when the second heat pump has to meet an increased energy demand.

[0032] Preferably, the communication link between the heat source and the multiple secondary heat pumps can also be established via the control unit. The control unit is designed as an electronic component that transmits information from one of the secondary heat pumps to the heat source. Preferably, the control unit can also receive information from the heat source.

[0033] The control unit can, for example, be located on the second heat pump.

[0034] According to a further preferred embodiment of the invention, the heat source comprises a district heating network or a combined heat and power plant.

[0035] A district heating network is typically used for the centralized generation and distribution of heat via a network of insulated pipes that transport hot water or steam from a production site to multiple consumers. Integrating such a system as a heat source into the heat supply system enables the utilization of economies of scale and the efficient distribution of heat over long distances, which can be particularly advantageous in urban or industrial environments. Due to the comparatively low required temperature of the supply line to the common heating circuit, residual heat from a return line of the district heating network can be used to great advantage.

[0036] A combined heat and power (CHP) plant, on the other hand, represents a decentralized method of generating heat and electricity. By combining the generation of electrical energy and usable heat in the same process, CHP plants typically achieve high efficiency. Using a CHP plant as a heat source within the heat supply system enables local, efficient energy conversion, which is particularly suitable for facilities with high energy demands, such as hospitals, schools, or swimming pools.

[0037] Even when using a combined heat and power plant as a heat source, it is possible and preferred to use only the residual heat from a return flow of the combined heat and power plant.

[0038] According to a further preferred embodiment of the invention, the heat source comprises a first heat pump.

[0039] As previously described, a heat pump operates on the principle of heat transfer from a cooler to a warmer medium. In this case, the warmer medium is the heat transfer fluid in the heating circuit. The heat pump can advantageously utilize external energy sources, such as ambient air, geothermal energy, or surface water, to extract heat and then raise it to a higher temperature level required for the flow of the heating circuit. This process allows the heat pump to efficiently provide heat, even at low outside temperatures.

[0040] Preferably, the first heat pump can also be combined with the return flow of a district heating network or with the heating return flow of a combined heat and power plant by raising the temperature of the respective return flow to the first temperature level.

[0041] Advantageously, the heat source can also be designed as several first heat pumps, which are connected hydraulically in parallel or in series in the heat circuit, for example.

[0042] According to a particularly preferred embodiment of the invention, the first heat pump is designed as a water-to-water heat pump.

[0043] A water-to-water heat pump extracts thermal energy, i.e., heat, from a water source, such as a river, lake, groundwater, or geothermal energy, and raises it to the required temperature level to meet the heating system's needs. Water-to-water heat pumps are characterized by comparatively high efficiency because ambient water, as a heat source, typically has a more constant temperature than air and also a higher heat capacity, allowing for easier heat extraction.

[0044] Alternatively, the first heat pump can preferably be designed as an air-to-water heat pump.

[0045] Another advantage is the large number of secondary heat pumps, each designed as a water-to-water heat pump. This results in the aforementioned advantages of water-to-water heat pumps also applying to the secondary heat pumps.

[0046] According to a particularly preferred embodiment of the invention, the heat source is designed to regulate the heat supply according to the requirements of the heat output.

[0047] The heat source thus provides the amount of heat required by the second heat pumps depending on the situation. As already described, this promotes very efficient operation of the heat supply system.

[0048] According to a further particularly preferred embodiment of the invention, it is provided that the first heat pump and the plurality of second heat pumps are each inverter-controlled.

[0049] By controlling the first and second heat pumps via an inverter, the first and second heat pumps can be adjusted relatively quickly to different operating points. Furthermore, inverter control allows for a reduction in the power consumption of the first and second heat pumps when they are not operating at full load. This also contributes to the energy-efficient operation of the heat supply system.

[0050] Another advantage resulting from control via an inverter is the reduced noise emission, especially of the first heat pump, which can be particularly relevant in residential areas.

[0051] According to a further particularly preferred embodiment of the invention, it is provided that the plurality of second heat pumps are connected to the heat source via the common heating circuit in a hydraulic parallel connection.

[0052] This means that the multiple second heat pumps can each independently extract heat from the flow of the common heating circuit, as each second heat pump has its own flow and return via the hydraulic parallel connection. This advantageously ensures that the flow of each of the second heat pumps actually reaches the first temperature level, since no heat is extracted from the flow before it reaches the respective second heat pump.

[0053] If, however, the second heat pumps were connected in series, they could no longer be reliably supplied with the first temperature level at the end of the flow, since the second heat pumps could extract heat from the first temperature level at the beginning of the flow, thus leading to a reduction in the first temperature level.

[0054] According to a further particularly preferred embodiment of the invention, it is provided that the common heating circuit comprises an intermediate unit which hydraulically separates an outer section of the common heating circuit from an inner section of the common heating circuit, wherein the intermediate unit enables heat transfer from an outer section of the flow to an inner section of the flow and enables heat transfer from an inner section of the return to an outer section of the return.

[0055] In this case, the heating circuit comprises three sections: the outdoor section, the intermediate section, and the indoor section. The outdoor section is located in the area of ​​the heat source, and the indoor section is located in the area of ​​the second heat pump. The intermediate section thermally connects the indoor and outdoor sections.

[0056] By hydraulically separating the inner section from the outer section via the intermediate section – but thermally connecting it – it is advantageous to use different heat transfer fluids in the inner and outer sections, which are best adapted to the respective section.

[0057] Each of the different heat transfer fluids is specifically selected for its respective temperature range to ensure high energy efficiency of the heat supply system. In particular, this system separation also makes it possible to use a very efficient heat transfer fluid for the first outdoor heat pump that is not approved for the second indoor heat pump.

[0058] The complete heat circuit could be structured as follows with regard to the heat transfer fluids used: The refrigerant R290 is used as the heat transfer fluid for the first heat pump. A brine solution or water (i.e., R718) is used as the heat transfer fluid for heat transfer from the first heat pump to the intermediate unit. Heat transfer from the intermediate unit to the second heat pumps can also be carried out using a brine solution. If heat transfer from the first heat pump to the intermediate unit is carried out using a brine solution, heat transfer from the intermediate unit to the second heat pumps can also be carried out using water as the heat transfer fluid. The second heat pumps themselves, which are intended for indoor use, can then operate, for example, with water (R718).

[0059] The intermediate unit may preferably comprise one or more heat exchangers to transfer the first temperature level from the supply line of the outdoor section to the supply line of the intermediate section and the indoor section. Similarly, the second temperature level may be transferred from the return line of the indoor section to the return line of the intermediate section and the outdoor section in the same way.

[0060] The control units for the multiple second heat pumps, as already described, can also be located in the area of ​​the intermediate unit and from here ensure the communicative connection between the heat source and the multiple second heat pumps.

[0061] For example, the control units in the area of ​​the intermediate unit can be arranged in a specially designed control cabinet.

[0062] The control units can preferably each have an operating interface, in particular switches, pushbuttons, rotary controls or a touchscreen.

[0063] According to a further preferred embodiment of the invention, the heat supply system comprises a plurality of buffer storage tanks, each of which is supplied by a second heat pump.

[0064] This means that it is advantageous for every second heat pump to be assigned a buffer storage tank, where a buffer storage tank is a storage tank for storing hot water and thus heat.

[0065] The buffer storage tank can, for example, be designed as a so-called stratified storage tank, which stores hot water in an upper area and increasingly colder water in a lower area.

[0066] The buffer storage tank can, for example, be used to supply hot water to the radiators of an apartment in which the second heat pump is located.

[0067] Preferably, the buffer storage tank contains hot water with a temperature of up to 75 °C.

[0068] According to a further preferred embodiment of the invention, the heat supply system comprises a plurality of second heat exchangers, each of which is fed by a buffer storage tank.

[0069] The second heat exchangers are preferably designed as so-called plate heat exchangers.

[0070] Advantageously, the second heat exchanger enables a fresh water supply for the respective apartment to which the corresponding second heat pump is assigned.

[0071] For example, the second heat exchangers can be designed to hold a maximum of 3 liters of water.

[0072] Preferably, the second heat exchangers are designed to hold a maximum of 1.1 liters of water. This generally ensures that the total amount of water in the second heat exchanger and in the water pipes to a tap does not exceed 3 liters.

[0073] With this relatively small volume of water, the flow rate is generally so high that no germs, and especially no Legionella bacteria, can form in the fresh water. Therefore, otherwise required, regular Legionella testing can be omitted.

[0074] The second heat exchangers are supplied with hot water from the buffer storage tank and transfer the heat of the hot water from the buffer storage tank to cold fresh water, which is thereby heated and can be drawn as heated fresh water, for example, from a tap in the apartment.

[0075] According to a further preferred embodiment of the invention, it is provided that the plurality of second heat pumps each include a buffer storage tank and a second heat exchanger in a common housing.

[0076] This results in a very compact design for the aforementioned components, making it particularly suitable for retrofitting as a heat supply system in existing buildings. The combined housing is advantageously no larger than a typical gas boiler in a gas-fired central heating system, so that retrofitting or replacement is also very easy to accomplish from a structural point of view.

[0077] Extensive and costly renovations are therefore advantageously avoided. Thus, a fossil fuel heating system can be replaced in a very simple and cost-effective way with an energy-efficient heating system that – depending on the electricity mix – produces low or no CO2 emissions.

[0078] The invention also relates to a multi-family residential building comprising a heat supply system according to the invention.

[0079] Thus, the advantages already described also apply to multi-family dwellings, allowing them to be heated economically and energy-efficiently.

[0080] According to a preferred embodiment of the invention, it is provided that pipes forming a return and a supply line are arranged at least partially in a chimney of the multi-family dwelling.

[0081] Particularly when retrofitting the heat supply system according to the invention in a multi-family dwelling or when replacing a system of gas-fired individual heating units in a dwelling with the heat supply system according to the invention, the return and supply pipes can be routed at least partially through the chimney of the multi-family dwelling. Major construction work on the multi-family dwelling can be avoided. In particular, it is then not necessary to penetrate the floor slabs and walls of the multi-family dwelling to lay the supply and return pipes. Instead, the chimney, which is no longer needed after the removal of the fossil fuel heating system, can be advantageously used. Since the chimney also connects all apartments in the multi-family dwelling, the necessary pipes can thus be easily routed to each apartment.

[0082] The invention further relates to a method for operating a heat supply system, wherein the heat supply system comprises a heat source and a plurality of heat sinks, wherein the heat source and the plurality of heat sinks are coupled to a heat fluid via a common heat circuit, wherein heat at a first temperature level is transported from the heat source to the plurality of heat sinks via a supply line of the common heat circuit, wherein heat at a second temperature level is transported from the plurality of heat sinks to the heat source via a return line of the common heat circuit, wherein the plurality of heat sinks extracts heat from the supply line, so that the second temperature level is reduced compared to the first temperature level, wherein the plurality of heat sinks is configured as a plurality of second heat pumps.

[0083] The method according to the invention is characterized in that each of the plurality of second heat pumps communicates with the heat source and heat requirements from each of the plurality of second heat pumps are transmitted to the heat source, so that the first temperature level is kept constant by means of the heat requirements.

[0084] The advantages already mentioned in connection with the heat supply system according to the invention also apply to the method according to the invention.

[0085] A further advantage of the method according to the invention arises from the possibility of easily determining the heat consumption of an apartment in the multi-family house or of a second heat pump via the flow rate through the supply or return line.

[0086] In particular, a building such as a multi-family house can be heated 100% regeneratively using this method if the required electrical energy was also generated regeneratively.

[0087] Converting an existing building heating system, currently powered by fossil fuels, to a heat supply system according to the invention, which then enables the implementation of the inventive method, is also comparatively cost-effective. Due to the high, energy-efficient flow temperatures of approximately 75 °C that can be achieved, the existing radiators can be retained instead of being replaced with a costly underfloor heating system. Similarly, costly modifications to the building envelope are not required and can be carried out at a later date.

[0088] Since the amount of heat transported from the heat source to the second heat pump at a constant temperature level depends solely on the flow rate, a heating cost calculation based on the flow rate can be easily created, for example.

[0089] Preferably, additional temperature sensors can also be provided to measure the temperature of the heat fluid transported to the second heat pump. This allows the consumed and billable amount of heat to be reliably determined even if the first temperature level is subject to short-term temperature fluctuations.

[0090] Thus, the first heat source can react immediately to a demand for heat output and adjust its operating point accordingly.

[0091] The invention is explained below by way of example with reference to embodiments shown in the figures.

[0092] They show: Fig. 1. An exemplary and schematic embodiment of a heat supply system according to the invention in a multi-family residential building, Fig. 2. An exemplary and schematic embodiment of a second heat pump of a heat supply system according to the invention and Fig. 3. An exemplary and schematic embodiment of a method according to the invention for operating a heat supply system is shown.

[0093] Identical objects, functional units, and comparable components are designated across all figures using the same reference symbols. These objects, functional units, and comparable components are identical in their technical characteristics unless explicitly or implicitly stated otherwise in the description.

[0094] Fig. Figure 1 shows an exemplary and schematic embodiment of a heat supply system 100 according to the invention in a multi-family residential building 400.

[0095] The heat supply system 100 according to the invention Fig. 1 comprises a first heat source 101, which is designed, for example, as a first heat pump 101.

[0096] The first heat pump 101 comprises an evaporator 102, a compressor 103, a condenser 104, and an expansion valve 105. The evaporator 102 absorbs ambient heat, for example, heat from the ambient air. The heat from the ambient air is used by the evaporator 102 to evaporate a heat transfer fluid, for example, the refrigerant R290. The compressor 104 compresses the evaporated heat transfer fluid so that it can be liquefied by the condenser 104. At the condenser 104, the refrigerant releases its previously absorbed heat to a supply line of a common heating circuit 200, which, for example, uses a brine solution as the heat transfer fluid.

[0097] The heat supply system 100 further comprises a number of heat sinks 301, 302, 303, 304, 305, 306, which are configured as secondary heat pumps 301, 302, 303, 304, 305, 306. For example, the heat supply system 100 comprises exactly six secondary heat pumps 301, 302, 303, 304, 305, 306.

[0098] For example, both the first heat pump 101 and the second heat pumps 301, 302, 303, 304, 305, 306 are inverter controlled.

[0099] Each of the second heat pumps 301, 302, 303, 304, 305, 306 also includes an evaporator, a compressor, a condenser and an expansion valve, each fulfilling the same functionality as in the first heat pump 101, whereby the evaporator of the second heat pumps 301, 302, 303, 304, 305, 306, however, extracts heat from the flow 201.

[0100] For example, each of the second heat pumps 301, 302, 303, 304, 305, 306 has a modular design. The individual modules consist of a base unit with a stratified storage tank (311, 312, 313, 314, 315, 316), a top section, the actual heat pump module, which can be inserted into the top section using a drawer mechanism, an outer casing, and the flexible connection piping to the existing heating system. This modular design makes each of the second heat pumps 301, 302, 303, 304, 305, 306 relatively easy to transport and install.

[0101] Each of the second heat pumps 301, 302, 303, 304, 305, 306 is also arranged within a multi-family dwelling 400, namely in its own residential unit 401, 402, 403, 404, 405, 406.

[0102] By each of the second heat pumps 301, 302, 303, 304, 305, 306 extracting heat from the flow 201 and making it available in the respective residential unit 401, 402, 403, 404, 405, 406, the second temperature level of the return 202 is reduced compared to the first temperature level of the flow 201.

[0103] The first heat pump 101 and the multiple second heat pumps 301, 302, 303, 304, 305, 306 are coupled via the common heating circuit 200, or via the flow 201 and the return 202. The flow 201, for example, has a first temperature level of 23 °C, while the return 202, for example, has a second temperature level of 18 °C.

[0104] The heat supply system 100 is designed to maintain the first temperature level constantly during operation, regardless of the heat extraction by the second heat pumps 301, 302, 303, 304, 305, 306.

[0105] Since the first temperature level is constant, the energy supplied to one of the second heat pumps 301, 302, 303, 304, 305, 306 by the first heat pump 101 depends solely on the flow rate of the heat fluid supplied to the second heat pump 301, 302, 303, 304, 305, 306. Therefore, heating costs can be easily calculated, for example, by recording the flow rate.

[0106] The common heating circuit 200 also includes an intermediate unit 210, which in turn includes a first heat exchanger 211, a supply pump 212 and a stratified buffer storage tank 213.

[0107] The intermediate unit 210 is also located within the multi-family residential building 400.

[0108] The first heat exchanger 211 receives the brine heated by the first heat pump 101 from an outdoor section 201' of the flow line 201 and transfers the heat to an intermediate section 201" of the flow line 201 in the area of ​​the intermediate unit 210. The brine, cooled by this process, from the outdoor section 201' of the flow line 201 is then pumped back to the first heat pump 101 via the outdoor section 202' of the return line 202 to be heated again.

[0109] The intermediate section 201" of the flow line 201 contains, for example, R718 as the heat transfer fluid, i.e., water, which is pumped by the supply pump 212 from the first heat exchanger 211 to the stratified buffer tank 213. Similarly, the intermediate section 202" of the return line 202 contains, for example, the refrigerant R718, i.e., water, which is pumped in the intermediate section 202" of the return line 202 from the stratified buffer tank 213 back to the first heat exchanger 211. For example, the stratified buffer tank 213 and the heat exchanger 211 are two separate components.

[0110] The stratified buffer storage tank 213, for example, has a volume of 2000 l of refrigerant R718. In principle, the stratified buffer storage tank 213 can also be designed to store volumes from 500 l up to 100,000 l, depending on the size of the respective heat supply system 100 and depending on whether the stratified buffer storage tank 213 is to be used as a seasonal storage tank.

[0111] The inlet of the stratified buffer storage tank 213 on the supply side 213' is located in the lower region of the stratified buffer storage tank 213, as is the outlet of the stratified buffer storage tank 213 on the supply side 213'. However, unlike the outlet on the supply side 213', the inlet is routed through a pipe inside the stratified buffer storage tank 213 to the upper region of the stratified buffer storage tank 213, since the warmer refrigerant naturally collects there. A stratification device integrated into the stratified buffer storage tank 213 (not shown in [reference missing]) [reference missing] Fig. 1), which also serves to calm the flow, mixing or turbulence of the different temperature layers in the stratified buffer storage tank 213 can be largely avoided. The inlet of the stratified buffer storage tank 213 on the supply side 213' has the first temperature level of the flow 201, while the outlet of the stratified buffer storage tank 213 on the supply side 213' has the second temperature level of the return 202.

[0112] On the discharge side 213" of the stratified buffer storage tank 213 there is a drain, so that the heat of the flow 201 can be discharged and supplied to the second heat pumps 301, 302, 303, 304, 305, 306.

[0113] On the discharge side 213" of the stratified buffer storage tank 213, there is also an inlet. Both the outlet and the inlet on the discharge side 213" are located in the lower section of the stratified buffer storage tank 213. The outlet on the discharge side 213" is routed via a pipe inside the stratified buffer storage tank 213 to the upper section of the stratified buffer storage tank 213 to extract the warmer refrigerant that collects there. The cooled refrigerant can be returned to the stratified buffer storage tank 213 via the inlet on the discharge side 213" in the lower section of the stratified buffer storage tank 213 without causing mixing or turbulence of the different temperature layers within the stratified buffer storage tank 213. Furthermore, as previously described, mixing of the different temperature layers within the stratified buffer storage tank 213 is also prevented by the integrated stratification device.

[0114] Since all connections of the stratified buffer storage tank 213 are located in the lower area, simple installation of the stratified buffer storage tank 213 in the heat supply system 100 is possible.

[0115] According to an alternative, exemplary embodiment, all connections of the stratified buffer storage tank 213 are routed upwards within a casing of the stratified buffer storage tank 213 on the rear of the stratified buffer storage tank 213. This allows existing connections of a previously installed gas heating system to be used for the installation of the stratified buffer storage tank 213 without any special modifications.

[0116] The outlet of the stratified buffer storage tank 213 on the discharge side 213'' represents the flow 201 of the common heating circuit 200 in an internal section 201'''. The inlet of the stratified buffer storage tank 213 on the discharge side 213'' represents the return 202 of the common heating circuit 200 in an internal section 202'''.

[0117] From the stratified buffer storage tank 213, the heating circuit 200 splits, for example, into two hydraulically parallel sub-circuits 200' and 200'', each comprising a hydraulic distributor 214', 214''.

[0118] For example, the hydraulic distributors 214', 214'' further divide the sub-circuits 200' and 200'' into three hydraulically parallel sub-circuits 221, 222, 223, 224, 225, 226, each of which is assigned to one of the residential units 401, 402, 403, 404, 405, 406. Three residential units located one above the other, 401, 402, 403 and 404, 405, 406, and the second heat pumps 301, 302, 303, 304, 305, 306 located therein, are each assigned to one of the distributors 214', 214''.

[0119] The multitude of second heat pumps 301, 302, 303, 304, 305, 306 are therefore connected to the first heat source 101 in a hydraulic parallel circuit via the common heating circuit 200.

[0120] The supply pipes of the return 202''' and the supply 201 in the inner section 201''' are each led through a chimney 411', 412 of the multi-family house 400.

[0121] In each of the residential units 401, 402, 403, 404, 405, 406 a second heat pump 301, 302, 303, 304, 305, 306 is arranged, which extracts heat from the flow 201''' of the indoor section 201''' of the flow 201, so that the first temperature level of the flow 201 is reduced to the second temperature level and is returned as return 202 via the corresponding distributor 214', 214'' to the buffer storage tank 213.

[0122] Each of the second heat pumps 301, 302, 303, 304, 305, 306 is individually controllable and provides the desired heat demand for heated domestic hot water and for heating water in a stratified storage tank 311, 312, 313, 314, 315, 316 in separate and thermally insulated areas.

[0123] Since the second heat pumps 301, 302, 303, 304, 305, 306 are connected to the first heat pump 101 at the communication level, a request for heat output can be transmitted to a second heat pump 301, 302, 303, 304, 305, 306 of the first heat pump 101 or a control unit of the first heat pump 101, so that the first heat pump 101 can increase its heat output accordingly.

[0124] A demand for heat output from a second heat pump 301, 302, 303, 304, 305, 306 leads to an increased heat extraction from the flow 201, so that the second temperature level, namely the temperature of the return 202, is reduced accordingly. In order to compensate for this increased temperature difference, the first heat pump 101 must increase its heat output accordingly.

[0125] The stratified storage tanks 311, 312, 313, 314, 315, 316 serve as buffer storage tanks 311, 312, 313, 314, 315, 316, which are each supplied by a second heat pump 301, 302, 303, 304, 305, 306.

[0126] For example, an upper section of the stratified storage tanks 311, 312, 313, 314, 315, 316 is intended for heating domestic hot water and a lower section for heating water. Both sections are separated by thermal insulation.

[0127] For example, the fresh water in the stratified storage tanks 311, 312, 313, 314, 315, 316 is heated to 48 °C according to a preset standard setting, whereas the heating water is heated to 72 °C according to the standard setting.

[0128] A circulation pump 321, 322, 323, 324, 325, 326 pumps the heating water to the radiators 331, 332, 333, 334, 335, 336. These radiators 331, 332, 333, 334, 335, 336 are, for example, ordinary wall-mounted radiators 331, 332, 333, 334, 335, 336, which can be used due to the high heating water temperature of 72 °C provided by the second heat pumps 301, 302, 303, 304, 305, 306. When converting a heat supply system originally designed for a gas boiler or gas-fired central heating system to the heat supply system 100 according to the invention, the existing radiators 331, 332, 333, 334, 335, 336 can thus be retained.

[0129] The water in the stratified storage tanks 311, 312, 313, 314, 315, 316, intended for heating the fresh water, is fed into a second heat exchanger 341, 342, 343, 344, 345, 346, where it heats the fresh water. The second heat exchangers 341, 342, 343, 344, 345, 346, for example, have a volume of 1.1 L and are designed as so-called plate heat exchangers 41, 342, 343, 344, 345, 35.

[0130] Fresh water can then be drawn from taps 351, 352, 353, 354, 355, 356.

[0131] Fig. Figure 2 shows an exemplary and schematic embodiment of a second heat pump 301, 302, 303, 304, 305, 306 of a heat supply system 100 according to the invention.

[0132] The second heat pump 301 is described below as an example for the structurally identical second heat pumps 301, 302, 303, 304, 305, 306 of the Fig. The first heat pump is described in section 1. The second heat pump, the 301, is a water-to-water heat pump controlled by an inverter.

[0133] As can be seen, the second heat pump 301 has a buffer storage tank 311 designed as a stratified storage tank 311.

[0134] The buffer storage tank 311 is connected together with the second heat exchanger 341, the evaporator 361, the compressor 362, the condenser 363 and the expansion valve (not shown in Fig. 2) arranged in a common housing 350. For the sake of clarity, only the framework of the common housing 350 is shown.

[0135] The heat transfer fluid supplied via the flow line 201 has a first temperature level and is evaporated in the evaporator 361. This extracts heat from the flow line 201, and the heat transfer fluid is discharged via the return line 202 at a second temperature level, which is lower than the first temperature level.

[0136] In compressor 362, the steam generated in this way is compressed and finally liquefied again in condenser 363. Condenser 363 transfers the heat previously extracted from the supply line 201 to the water in buffer storage tank 311. Finally, the pressure of the heat transfer fluid is reduced via expansion valve 364 so that it can be evaporated again in evaporator 361.

[0137] The second heat pump 301 also has a control unit 365, which is, for example, arranged on an inner wall of the common housing 350 and is therefore in Fig. Figure 2 is only shown schematically. The second heat pump 301 is communicatively connected to the first heat pump 101 via the control unit 365. If a user of the second heat pump 301, or a resident of the residential unit 401, now makes a heat demand to the second heat pump 301, for example by opening a control valve of the radiator 331, this represents a withdrawal of heat from the buffer storage tank 311 and the temperature in the buffer storage tank 311 drops.

[0138] To raise the temperature in the buffer tank 311 again, the second heat pump 301 can extract heat from the flow pipe 201 and supply it to the buffer tank 311. Simultaneously, the second heat pump 301 can transmit information about the heat extraction from the flow pipe 201 to the first heat pump 101 via the communication link, so that the first heat pump 101 can proactively adjust its operating point to maintain a constant initial temperature level.

[0139] For example, the control unit also includes a flow rate measurement unit to measure the flow rate of the heat fluid through the second heat pump 301, as well as a temperature sensor assigned to the supply line 201 and a temperature sensor assigned to the return line 202.

[0140] Finally, the second heat pump 301 shown as an example also includes a pump group 360, which supplies the radiator 331 assigned to the second heat pump 301 with heat fluid from the buffer storage tank 311 by means of hydraulic pumps.

[0141] Fig. Figure 3 shows, by way of example and schematically, a possible embodiment of a method according to the invention for operating a heat supply system 100.

[0142] The heat supply system 100 comprises a heat source 101 and a plurality of second heat sources 301, 302, 303, 304, 305, 306, wherein the first heat source 101 and the plurality of second heat sources 301, 302, 303, 304, 305, 306 are coupled via a common heat circuit 200 with a supply 201 and a return 202.

[0143] For example, the heat source 101 is designed as the first heat pump 101 and the multitude of second heat sources 301, 302, 303, 304, 305, 306 are each designed as the second heat source 301, 302, 303, 304, 305, 306.

[0144] In a first process step 501, a first temperature level in the feed line 201 is provided by the heat source 101.

[0145] In a second process step 502, heat is extracted from the flow 201 by the multiple second heat pumps 301, 302, 303, 304, 305, 306. The return 202 therefore has a second temperature level, which is lower than the first temperature level of the flow 201.

[0146] Simultaneously with step 502, each of the multiple second heat pumps 301, 302, 303, 304, 305, 306 communicates with the first heat pump 101 in step 503 and transmits the amount of heat extracted from the flow or a resulting requirement for heat output.

[0147] In step 504, the first heat pump 101 receives the heat output requirements and adjusts its heat output to the requested demand.

[0148] As a result, the first temperature level of the flow 201 can be kept constant in step 505. Reference symbol list 100 Heat supply system 101 Heat source, first heat pump 102 evaporators of the first heat pump 103 compressors of the first heat pump 104 condensers of the first heat pump 105 Expansion valve of the first heat pump 200 Common heating circuit 201 Pre-flow of the common heating circuit 201' Outer section of the supply line of the common heating circuit 201'' Intermediate section of the supply line of the common heating circuit 201''' Inner section of the flow of the common heating circuit 202 Return of the common heating circuit 202' Outer section of the return of the common heating circuit 202'' Intermediate section of the return line of the common heating circuit 202''' Inner section of the return of the common heating circuit 210 Intermediate unit 211 second heat exchanger 212 Supply pump of the intermediate unit 213 layered buffer storage 213' Feed side of the layered buffer storage 213'' Discharge side of the stratified buffer storage tank 214', 214'' Hydraulic distributor 221, 222, 223, 224, 225, 226 sub-circle 301, 302, 303, 304, 305, 306 Heat sink, second heat pump 311, 312, 313, 314, 315, 316 Separation layer storage 321, 322, 323, 324, 325, 326 Circulating pumps 331, 332, 333, 334, 335, 336 radiators 341, 342, 343, 344, 345, 346 Second heat exchangers 350 Common housing of the second heat pump 351, 352, 353, 354, 355, 356 dispensing points 360 pump group 361 evaporators 362 compressors 363 condensers 400 multi-family residential building Units 401, 402, 403, 404, 405, 406 411', 411'' Chimney of the apartment building 501 Provision of an initial temperature level in the supply line by the first heat source 502 Extraction of heat from the supply line through the multitude of secondary heat sources 503 Communication of every second heat pump with the first heat pump to transmit a current request for heat output 504 Adjusting the heat output of the first heat pump to the required heat demand 505 Maintaining the first temperature level of the flow constant QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2019 / 220303 A1

[0007] EP 2 322 880 B1

[0008] EP 3 371 517 B1 [0009, 0026]

Claims

[1] Heat supply system (100), comprising a heat source (101) and a multitude of heat sinks (301, 302, 303, 304, 305, 306), wherein the heat source (101) and the multitude of heat sinks (301, 302, 303, 304, 305, 306) are coupled to a heat fluid via a common heat circuit (200), wherein heat at a first temperature level can be transported from the heat source (101) to the multitude of heat sinks (301, 302, 303, 304, 305, 306) via a feed line (201) of the common heat circuit (200), wherein heat at a second temperature level can be transported from the multitude of heat sinks (301, 302, 303, 304, 305, 306) to the heat source (101) via a return flow (202) of the common heat circuit (200), where the second temperature level is reduced compared to the first temperature level and wherein the plurality of heat sinks (301, 302, 303, 304, 305, 306) is configured as a plurality of second heat pumps (301, 302, 303, 304, 305, 306), characterized by , that each of the multiple second heat pumps (301, 302, 303, 304, 305, 306) is connected to the heat source (101) at the communication level, so that heat requirements from each of the multiple second heat pumps (301, 302, 303, 304, 305, 306) can be transmitted to the heat source (101) and that the heat source (101) is designed to keep the first temperature level constant by means of the heat requirements. [2] Heat supply system (100) according to claim 1, characterized by , that the heat source (101) comprises a district heating network or a combined heat and power plant. [3] Heat supply system (100) according to at least one of claims 1 and 2, characterized by , that the heat source (101) comprises a first heat pump (101). [4] Heat supply system (100) according to claim 3, characterized by , that the first heat pump (101) is designed as a water-to-water heat pump. [5] Heat supply system (100) according to at least one of claims 1 to 4, characterized by , that the heat source (101) is designed to regulate heat supply according to the requirements of heat output. [6] Heat supply system (100) according to at least one of claims 3 to 5, characterized by , that the first heat pump (101) and the multitude of second heat pumps (301, 302, 303, 304, 305, 306) are each inverter controlled. [7] Heat supply system (100) according to at least one of claims 1 to 6, characterized by , that the multitude of second heat pumps (301, 302, 303, 304, 305, 306) are connected to the heat source (10) via the common heat circuit (200) in a hydraulic parallel connection. [8] Heat supply system (100) according to at least one of claims 1 to 7, characterized by , that the common heating circuit (200) comprises an intermediate unit (210) which hydraulically separates an outer section (201') of the common heating circuit (200) from an inner section (201''') of the common heating circuit (200), wherein the intermediate unit (210) enables heat transfer from an outer section (201') of the flow (201) to an inner section (201''') of the flow (201) and enables heat transfer from an inner section (202''') of the return (202) to an outer section (202') of the return (202). [9] Heat supply system (100) according to at least one of claims 1 to 8, characterized by , that the heat supply system (100) comprises a plurality of buffer storage tanks (213), each buffer storage tank (213) being supplied by a second heat pump (301, 302, 303, 304, 305, 306). [10] Heat supply system (100) according to at least one of claims 1 to 9, characterized by , that the heat supply system comprises a multitude of secondary heat exchangers, with each secondary heat exchanger being fed from a buffer storage tank. [11] Heat supply system (100) according to at least one of claims 1 to 10, characterized by , that the heat supply system (100) comprises a plurality of second heat exchangers (341, 342, 343, 344, 345, 346), wherein each second heat exchanger (341, 342, 343, 344, 345, 346) is supplied by a buffer storage tank (213). [12] Multi-family dwelling (400) comprising a heat supply system (100) according to at least one of claims 1 to 11. [13] Multi-family dwelling (400) according to claim 12, characterized by, that pipelines forming a return (202) and a supply (201) are at least partially arranged in a chimney (411', 411'') of the multi-family dwelling (400). [14] Method for operating a heat supply system (100), wherein the heat supply system comprises a heat source (101) and a plurality of heat sinks (301, 302, 303, 304, 305, 306), wherein the heat source (101) and the multitude of heat sinks (301, 302, 303, 304, 305, 306) are coupled to a heat fluid via a common heat circuit (200), wherein heat is transported at a first temperature level from the heat source (101) to the multitude of heat sinks (301, 302, 303, 304, 305, 306) via a supply line (201) of the common heat circuit (200) (501), wherein heat at a second temperature level is transported from the multitude of heat sinks (301, 302, 303, 304, 305, 306) to the heat source (101) via a return flow (202) of the common heat circuit (200), wherein the multitude of heat sinks (301, 302, 303, 304, 305, 306) extract heat from the flow (201) (502), so that the second temperature level is reduced compared to the first temperature level and wherein the plurality of second heat pumps (301, 302, 303, 304, 305, 306) is designed as a plurality of heat pumps, characterized by , that each of the multiple second heat pumps (301, 302, 303, 304, 305, 306) communicates with the heat source (101) (503) and heat requirements from each of the multiple second heat pumps (301, 302, 303, 304, 305, 306) are transmitted to the heat source (101), so that the first temperature level is kept constant by means of the heat requirements (505).

Images