ARRANGEMENT FOR HEAT GENERATION

Description

[0001] The invention relates to an arrangement for heat generation using a CO₂ heat pump. An arrangement for heat generation using a CO₂ heat pump is known from JP 2006 308278.

[0002] CO₂ heat pumps are characterized by the high environmental compatibility of the refrigerant CO₂ (also known as R744) used, as well as by their high efficiency. CO₂ is a 100% natural gas, non-toxic, non-explosive, non-flammable, usable at ambient temperatures down to -25°C, not artificially created by the chemical industry, has a global warming potential (GWP) of 1, an ozone depletion potential (ODP) of 0, and is available in large quantities without the risk of shortage. Furthermore, CO₂ heat pumps do not require a drive for the refrigerant cycle, thus reducing their electrical energy consumption during operation. However, for efficient operation, they require a large temperature difference (temperature spread) between the outlet and inlet temperatures (high ΔT), making them unsuitable for residential applications, including, for example, apartments.Hotels, student dormitories, retirement homes, canteens, apartment buildings, almost exclusively for hot water preparation (i.e., domestic hot water), and also in industry. When heating rooms or buildings, the ΔT is too small, making the operation of a CO₂ heat pump uneconomical.

[0003] The object of the present invention is to enable the use of a CO2 heat pump even in heat consumers where the ΔT is small.

[0004] According to the invention, this problem is solved by an arrangement according to claim 1.

[0005] The term "in flow connection" is intended to describe that a fluid flow flows directly from the fluid outlet of one of the components of the arrangement into the fluid inlet of another component, or that the fluid flow flows indirectly from the fluid outlet of one component via one or more intermediate components or together with another fluid flow to the fluid inlet of another component.

[0006] The invention is based on the realization that the use of a CO2 heat pump often fails because the return temperature in a fluid circuit with a small ΔT - such as in a heating system for rooms or buildings - is too high to be suitable as an inlet temperature to the CO2 heat pump.

[0007] The measures according to the invention enable economical operation of a CO₂ heat pump even with a heat consumer or heat exchanger that has only a small temperature difference. By integrating a fluid-to-fluid heat pump into a fluid circuit between the fluid outlet of the (at least one) heat exchanger and the fluid inlet of a CO₂ heat pump, as described in the invention, sufficient heat can be extracted from the fluid flow exiting the heat exchanger to ensure that a first fluid flow exiting the fluid-to-fluid heat pump has a temperature equal to or lower than the maximum inlet temperature of the CO₂ heat pump. Furthermore, the heat extracted from the first fluid flow can be used to heat the second fluid flow through the fluid-to-fluid heat pump to such an extent that its heat can also be used efficiently.

[0008] The invention is based on the idea of ​​using a fluid / fluid heat pump to extract heat from the fluid flow exiting the heat exchanger, which has a temperature that is on the one hand too high to introduce the fluid flow into the CO2 heat pump, but on the other hand too low to be able to use its heat effectively, and to provide two fluid flows, both of which can be used again profitably, the first of which is a cold fluid flow whose temperature is lower than that of the incoming fluid flow and which is suitable for entry into the CO2 heat pump, and the second of which is a warm fluid flow whose temperature is higher than that of the incoming fluid flow and whose heat can be used profitably again.

[0009] In a preferred embodiment of the invention, the circulating fluid flow between the heat exchanger and the fluid / fluid heat pump splits. A first partial flow enters the first fluid inlet as the first fluid flow, and a second partial flow enters the second fluid inlet as the second fluid flow. After exiting the hot fluid outlet, the second fluid flow joins the fluid flow from the CO2 heat pump to the heat exchanger. This division into two partial flows effectively separates the fluid flow from the heat exchanger into a cold fluid flow and a hot fluid flow, based on its temperature. The second fluid flow—the hot fluid flow—is at a sufficiently high temperature to be fed back into the circulating fluid flow at the inlet side of the heat exchanger.In this embodiment, it is also conceivable that the circulating fluid flow only splits into the first and second partial flow within the fluid / fluid heat pump.

[0010] In another embodiment, the fluid flow exiting the heat exchanger is not split, but rather fed entirely as the first fluid flow to the cold fluid outlet in the fluid-to-fluid heat pump. The second fluid inlet and the hot fluid outlet of the fluid-to-fluid heat pump – i.e., the second fluid flow – are part of a second fluid circuit, which includes a further heat exchanger.

[0011] According to the invention, the arrangement further comprises a fluid storage unit comprising a first area for storing cold fluid, a second area for storing warm fluid, and a third area for storing fluid whose temperature lies between that of the cold fluid and that of the warm fluid, wherein each of the three areas has at least one fluid inlet and at least one fluid outlet, and a fluid inlet of the first area is in flow communication with the cold fluid outlet of the fluid / fluid heat pump and a fluid outlet of the first area is in flow communication with the fluid inlet of the CO2 heat pump.a fluid inlet of the second area is in flow communication with the fluid outlet of the CO2 heat pump and a fluid outlet of the second area is in flow communication with the fluid inlet of the heat exchanger, and a fluid inlet of the third area is in flow communication with the fluid outlet of the heat exchanger and a fluid outlet of the third area is in flow communication with the first fluid inlet of the fluid / fluid heat pump.

[0012] The term "fluid storage" here also refers to separate, individual storage units, each forming one of the areas, for example, three adjacent containers or tanks. However, the fluid storage unit can also be a single container whose interior is divided into three areas, for example, a tank with three chambers.

[0013] If all fluid inlets and outlets of the CO₂ heat pump, the heat exchanger, and the fluid-to-fluid heat pump are connected to the fluid storage unit, the fluid storage unit acts as a buffer between these components, eliminating the need to coordinate their flow rates. However, the system also allows for direct fluid flow between the components, in addition to the flow from the components to the fluid storage unit and vice versa. For example, a flow can branch off from the flow between the heat exchanger outlet and the fluid storage unit inlet to the first inlet of the fluid-to-fluid heat pump.

[0014] Preferably, the second section of the fluid storage unit has a second fluid inlet, which is connected to the hot fluid outlet of the fluid-to-fluid heat pump, or the second fluid flow, after exiting the hot fluid outlet of the fluid-to-fluid heat pump, flows into the fluid flow from the CO₂ heat pump to the fluid storage unit. This ensures that all fluid flows pass through the fluid storage unit, providing a fluid buffer for all fluid inlets and outlets.

[0015] In an advantageous embodiment of the invention, the arrangement comprises a second heat exchanger with a fluid inlet and a fluid outlet, wherein the second region of the fluid reservoir has a second fluid outlet that is in flow communication with the fluid inlet of the second heat exchanger, and the first and / or the third region of the fluid reservoir has a second fluid inlet that is in flow communication with the fluid outlet of the second heat exchanger. Such a second heat exchanger could have a larger temperature difference, i.e., a larger ΔT, between its fluid inlet temperature and its fluid outlet temperature than the first heat exchanger.

[0016] Such a second heat exchanger with a large ΔT can also be integrated into an arrangement according to the invention without a fluid storage tank. For example, the fluid outlet of the CO₂ heat pump can be in flow communication with both the fluid inlet of the first heat exchanger and the fluid inlet of the second heat exchanger, and the fluid outlet of the second heat exchanger can lead into the cold fluid flow from the cold fluid outlet of the fluid / fluid heat pump to the CO₂ heat pump or into the fluid flow from the first heat exchanger to the fluid / fluid heat pump.

[0017] The embodiments described above show that even a heat exchanger with a large ΔT can be readily integrated into an arrangement according to the invention.

[0018] In a preferred embodiment of the invention, the fluid storage unit is a highly stratified storage unit comprising at least three layers, wherein the bottom layer corresponds to the first region, the top layer to the second region, and the middle layer to the third region. This simplifies the manufacturing of the fluid storage unit. Furthermore, a stratified storage unit requires less space compared to individual, separate fluid storage units for the three regions.

[0019] Advantageously, the fluid circulating in the fluid circuit is water. This allows for a cost-effective design of the arrangement.

[0020] In an advantageous embodiment of the invention, the first heat exchanger is part of a space or building heating system. Particularly preferably, the second heat exchanger is part of a domestic hot water circuit. In space or building heating systems, there are small temperature differences ΔT between the flow and return temperatures, i.e., between the inlet and outlet temperatures of the first heat exchanger, with high return temperatures. For example, the temperature differences ΔT in space or building heating systems can be in the range of 2°C to 30°C, preferably in the range of 5°C to 20°C, at return temperatures of 25°C and higher, preferably 30°C and higher. A domestic hot water circuit has a large ΔT because domestic hot water includes both hot and cold water, and therefore the return temperature is significantly lower than in a heating circuit.With an arrangement according to the invention, a room or building heating system and a domestic hot water circuit can be operated extremely efficiently and in a very environmentally friendly manner.

[0021] Preferably, the temperature difference between the fluid entering the CO₂ heat pump and the fluid exiting it is at least 20°C, and the temperature difference is particularly preferably in the range of 40°C to 85°C and most preferably in the range of 45°C to 70°C. In these ranges, economical to optimal operation of a CO₂ heat pump is ensured.

[0022] Advantageously, the temperature of the fluid entering the CO₂ heat pump is at most 30°C, and is particularly preferably in the range of 2°C to 25°C, and most preferably in the range of 5°C to 20°C. This allows an arrangement according to the invention to be used in an extremely wide range of building technology applications.

[0023] In this case, the temperature of the fluid exiting the COz heat pump is preferably at least 50°C, and is particularly preferably in the range of 55°C to 95°C, and most preferably in the range of 60°C to 90°C.

[0024] In a further advantageous embodiment of the invention, the fluid-to-fluid heat pump is an air-to-water heat pump, wherein the second fluid flow is an air flow. Particularly preferably, the second fluid inlet of the air-to-water heat pump is in contact with the ambient air of the room or building, and the hot fluid outlet of the air-to-water heat pump discharges into the room or building. Using an air-to-water heat pump can further reduce the costs of an arrangement according to the invention.

[0025] In an advantageous embodiment of the invention, the cold fluid outlet of the fluid-to-fluid heat pump can be connected to the supply line of a cooling circuit, and the first fluid inlet of the fluid-to-fluid heat pump can be connected to the return line of a cooling circuit. Furthermore, the fluid inlet of the CO₂ heat pump can be connected to the fluid outlet of the first section of the fluid storage tank. The first section of the fluid storage tank has a second fluid inlet that is in flow communication with the fluid outlet of a second heat exchanger, which has a large ΔT. With these measures, an arrangement according to the invention can be operated in summer in which the temperature of the return line of the second heat exchanger is low enough to be fed directly or via the first section of the fluid storage tank to the fluid inlet of the CO₂ heat pump.The first fluid flow of the fluid / fluid heat pump can then be part of a cooling circuit, whereas the second fluid flow of the fluid / fluid heat pump supplies the heat extracted from the first fluid flow via the fluid circuit to at least one second heat exchanger, which can be used, for example, to heat a domestic hot water circuit.

[0026] The invention will be explained in more detail below with reference to the drawings as an example.

[0027] The Figures 1 to 9 show examples of an arrangement, where only Figures 4 , 5 , 6 , 8 , 9 show an arrangement according to the invention with heat storage.

[0028] The illustrated embodiments of an arrangement 1 according to the invention include a CO₂ heat pump 2, a heat exchanger 3 and a fluid / fluid heat pump 4, which can be connected in series in this order in a fluid circuit 5 through which a fluid flows.

[0029] The fluid can be a liquid or gaseous medium and acts as a heat transfer medium.

[0030] The CO2 heat pump 2 has a fluid inlet 6 and a fluid outlet 7, with a maximum fluid inlet temperature specified for the CO2 heat pump 2.

[0031] The heat exchanger 3 also has a fluid inlet 8 and a fluid outlet 9, with its fluid outlet temperature being higher than the maximum fluid inlet temperature specified for the CO2 heat pump 2.

[0032] The fluid-to-fluid heat pump 4 has a first fluid inlet 10 and a second fluid inlet 11, as well as a cold fluid outlet 12 and a hot fluid outlet 13. The first fluid inlet 10 is connected to the cold fluid outlet 12, and the second fluid inlet 11 is connected to the hot fluid outlet 13. Therefore, a first fluid flow 14 entering through the first fluid inlet 10 is directed to the cold fluid outlet 12, while a second fluid flow 15 entering through the second fluid inlet 11 is directed to the hot fluid outlet 13. The fluid-to-fluid heat pump 4 is configured to extract heat from the first fluid flow 14 and transfer it to the second fluid flow 15.

[0033] The fluid / fluid heat pump 4 is further configured to extract so much heat from the first fluid flow 14 that the temperature of the fluid flow 16 exiting the cold fluid outlet 12 is at most equal to the fluid inlet temperature specified as the maximum fluid inlet temperature for the COz heat pump 2.

[0034] The fluid outlet 9 of the heat exchanger 3 is in flow communication with the first fluid inlet 10 of the fluid / fluid heat pump 4.

[0035] The cold fluid outlet 12 of the fluid / fluid heat pump 4 is in flow communication with the fluid inlet 6 of the COz heat pump 2.

[0036] In the figures, the fluid flows are represented as connecting lines between the components, with the arrows indicating the direction of flow of the respective fluid flow.

[0037] The structural design of the connections is achieved using pipelines.

[0038] At the in Figure 1In the arrangement 1 shown, the fluid flow 17 coming from the fluid outlet 9 of the heat exchanger 3 splits into two partial flows before reaching the fluid / fluid heat pump 4, of which a first partial flow flows as the first fluid flow 14 into the first fluid inlet 10 and the second partial flow flows as the second fluid flow 15 into the second fluid inlet 11.

[0039] Heat is extracted from the first partial flow, i.e., the first fluid flow 14, in the fluid / fluid heat pump 4. It exits as a cold fluid flow 16 from the cold fluid outlet 12 and enters the fluid inlet 6 of the CO₂ heat pump 2.

[0040] The heat extracted from the first fluid flow 14 is supplied to the second partial flow, i.e., the second fluid flow 15, in the fluid / fluid heat pump 4, so that the second partial flow emerges as a warm fluid flow 18 from the warm fluid outlet 13. This warm fluid flow 18 merges with the fluid flow 19 exiting from the fluid outlet 7 of the CO₂ heat pump 2; the combined fluid flow 20 enters the fluid inlet 8 of the heat exchanger 3.

[0041] In the Figure 1 In the arrangement shown, a four-way valve 21 is connected in the two fluid flows 17, 20 to and from the heat exchanger 3, the first inlet 22 of which is connected to the fluid outlet 9 of the heat exchanger 3, and the second inlet 23 of which is connected to the fluid outlet 7 of the COa heat pump 2 and to the hot fluid outlet 13 of the fluid / fluid heat pump 4, and the first outlet 24 of which is connected to the first fluid inlet 10 and in the Figure 1In the illustrated embodiment, due to the fork, the second fluid inlet 11 of the fluid / fluid heat pump 4 is also connected, and its second outlet 25 is connected to the fluid inlet 8 of the heat exchanger 3. The four-way valve 21 can be switched in at least one operating mode such that the fluid flow 17 entering the first inlet 22 exits again from the first outlet 24, and the fluid flow 20 entering the second inlet 23 exits again from the second outlet 25. In other operating modes, the four-way valve 21 can be switched such that the incoming fluid flows 17 and 20 are mixed together in predetermined ratios. For example, the temperature of the fluid flow 19 exiting the CO2 heat pump 2 can be at least 60°C, whereas in some cases the temperature of the fluid flow 26 entering the heat exchanger 3 must be in the range of 45°C to 55°C.

[0042] The in Figure 2 The arrangement shown corresponds to the one in Figure 1 The arrangement shown is identical except for the two fluid flows 14, 15 in the fluid / fluid heat pump 4. In the arrangement according to... Figure 2 The entire fluid flow 17 coming from the heat exchanger 3 enters the first fluid inlet 10 of the fluid / fluid heat pump 4 and forms the first fluid flow 14 from which heat is extracted and which exits the cold fluid outlet 12 of the fluid / fluid heat pump 4 and enters the fluid inlet 6 of the CO2 heat pump 2.

[0043] The second fluid flow 15 in the fluid / fluid heat pump 4 is part of a second fluid circuit 27, which includes another heat consumer 28, e.g. another heat exchanger.

[0044] The in Figure 3 The arrangement shown corresponds to the one in Figure 1The arrangement shown includes a second heat exchanger 29 connected in the fluid circuit 5. The second heat exchanger 29 has a large temperature difference ΔT between the fluid inlet 30 and the fluid outlet 31, as is the case, for example, in a domestic hot water circuit 32, to which the second heat exchanger 29 could belong. The (first) heat exchanger 3 could, for example, be part of a space or building heating system.

[0045] A partial flow 33 branches off from the fluid flow 19 exiting the fluid outlet 7 of the CO₂ heat pump 2 and flows to the fluid inlet 30 of the second heat exchanger 29. The fluid flow 34 coming from the fluid outlet 31 of the second heat exchanger 29 flows into the cold fluid flow 16, which flows from the cold fluid outlet 12 of the fluid / fluid heat pump 4 to the fluid inlet 6 of the CO₂ heat pump 2.

[0046] The in Figure 4 The illustrated embodiment of the invention is also based on the arrangement according to Figure 1, where a fluid storage tank 35 is connected in the fluid flows between CO2 heat pump 2, heat exchanger 3 and fluid / fluid heat pump 4.

[0047] The fluid storage unit 35 has at least three areas 36, 37, 38: a first area 36 for storing cold fluid, a second area 37 for storing warm fluid and a third area 38 for storing fluid whose temperature is between that of the cold fluid and that of the warm fluid.

[0048] The first section 36 has a fluid inlet 39, to which the cold fluid outlet 12 of the fluid / fluid heat pump 4 is connected, and has a fluid outlet 40, which is connected to the fluid inlet 6 of the CO₂ heat pump 2. The cold fluid outlet 12 of the fluid / fluid heat pump 4 is thus in flow communication with the fluid inlet 6 of the CO₂ heat pump 2 via the first section 36 of the fluid storage tank 35.

[0049] The second section 37 has two fluid inlets 41, 42 and one fluid outlet 43. The first fluid inlet 41 of the second section 37 is connected to the fluid outlet 7 of the CO₂ heat pump 2. The second fluid inlet 42, which is located at a predetermined distance below the first fluid inlet 41, is connected to the hot fluid outlet 13 of the fluid-to-fluid heat pump 4.

[0050] The fluid outlet 43 of the second area 37 is connected to the fluid inlet 8 of the heat exchanger 3 via a three-way valve 44.

[0051] Thus, the fluid outlet 7 of the CO2 heat pump 2 and the hot fluid outlet 13 of the fluid / fluid heat pump 4 are connected via the second area 37 of the fluid storage tank 35 to the fluid inlet 8 of the heat exchanger 3.

[0052] It is also taken into account that the second area 37 of the fluid storage 35 has only one fluid inlet 41 and that the fluid flow 18 from the hot fluid outlet 13 of the fluid / fluid heat pump 4 flows into the fluid flow 19 from the fluid outlet 7 of the CO2 heat pump 2.

[0053] The temperature within each section of the fluid storage tank 35 is not constant, but decreases from top to bottom, so that, for example, the fluid has the hottest temperature at the top of the second section 37 of the fluid storage tank 35, and the fluid flow 19 coming from the CO₂ heat pump 2 is preferably introduced there. The fluid flow 18 coming from the fluid / fluid heat pump 4 typically has a lower temperature than the fluid flow 19 coming from the CO₂ heat pump 2 and is therefore preferably introduced – as in Figure 4As shown, the fluid flow 19 coming from the CO2 heat pump 2 is introduced at a predetermined distance below the inlet point 41. This ensures that the maximum temperature present in the second area 37 (above) remains as high as possible for as long as possible.

[0054] For the same reasons, the fluid temperature is lowest at the bottom of the first area 36, ​​so the fluid outlet 40 from the first area 36 is located there.

[0055] The third section 38 has a fluid inlet 45 and a fluid outlet 46. The fluid inlet 45 is connected to the fluid outlet 9 of the heat exchanger 3. The fluid outlet 46 of the third section 38 is connected to the two fluid inlets 10, 11 of the fluid-to-fluid heat pump 4, wherein the fluid flow 47 from the fluid outlet 46 of the third section 38 branches off before the two fluid inlets 10, 11 of the fluid-to-fluid heat pump 4, as already described in conjunction with the embodiment shown in Figure 1. Figure 1 described.

[0056] It is also thought that the third area 38 - as in Figure 5shown - has at least two fluid outlets 46a, 46b, for example a first fluid outlet 46a, which is located at the bottom in the third area 38 and is connected to the first fluid inlet 10 of the fluid / fluid heat pump 4, so that the fluid flow 47a from the fluid outlet 46a is directed to the cold fluid outlet 12, and a second fluid outlet 46b, which is located at the top in the third area 38 and is connected to the second fluid outlet 11 of the fluid / fluid heat pump 4, so that the fluid flow 47b from the fluid outlet 46b is directed to the hot fluid outlet 13.

[0057] Thus, the fluid outlet 9 of the heat exchanger 3 is in flow connection via the third area 38 of the fluid storage tank 35 with the fluid inlets 10, 11 of the fluid / fluid heat pump 4.

[0058] As mentioned above, a three-way valve 44 is arranged in the fluid flow 48 from the second section 37 of the fluid storage unit 35 to the fluid inlet 8 of the heat exchanger 3. This three-way valve 44 has a first and a second inlet 49, 51 and an outlet 50. The first inlet 49 is connected to the fluid outlet 43 of the second section 37 of the fluid storage unit 35. The outlet 50 is connected to the fluid inlet 8 of the heat exchanger 3, and a branch from the fluid flow 52, ​​which flows from the fluid outlet 9 of the heat exchanger 3 to the fluid inlet 45 of the third section 38 of the fluid storage unit 35, opens into the second inlet 51.

[0059] The three-way valve 44 can be switched in at least one operating mode such that the fluid flow 48 coming from the second section 37 of the fluid storage tank 35 enters the inlet 49 of the three-way valve 44 and exits from its first outlet 50, flowing to the fluid inlet 8 of the heat exchanger 3. In other operating modes, the three-way valve 44 can be switched such that the fluid flows entering the two inlets 49 and 51 are mixed together in predetermined ratios.

[0060] The in Figure 6 The illustrated embodiment corresponds to the embodiment according to Figure 4 with a second heat exchanger 29 according to the embodiment shown Figure 3 .

[0061] The second section 37 of the fluid storage unit 35 has a second fluid outlet 53, located at the top of the second section 37. The fluid temperature is highest at this point in the fluid storage unit 35, and the fluid flow 19 from the fluid outlet 7 of the CO₂ heat pump 2 is also introduced into the fluid storage unit 35 at this point. The second fluid outlet 53 of the second section 37 is connected to the fluid inlet 30 of the second heat exchanger 29, so that fluid enters at the same temperature as it exits the CO₂ heat pump 2.

[0062] The first section 36 of the fluid storage tank 35 has a second fluid inlet 54, which is connected to the fluid outlet 31 of the second heat exchanger 29. In this embodiment, it is assumed that there is a large temperature difference ΔT between the fluid inlet 30 and the fluid outlet 31 of the second heat exchanger 29, as is the case, for example, when the second heat exchanger 29 belongs to a domestic hot water circuit 32. Corresponding to this large temperature difference ΔT, the fluid inlet 30 of the second heat exchanger 29 is connected to the second section 37 of the fluid storage tank 35, and as high up as possible there, and the fluid outlet 31 of the second heat exchanger 29 is connected to the first section 36, which contains cold fluid.

[0063] The in Figure 7 The arrangement shown corresponds to the arrangement from Figure 2, where the fluid / fluid heat pump 4 is an air / fluid heat pump 55 and, in particular, an air / water heat pump. The second fluid flow 15, to which the heat extracted from the first fluid flow 14 is transferred, is here an air flow 56.

[0064] If the arrangement is used for heat generation in a space and / or building heating system - i.e., if the heat exchanger 3 is part of a space and / or building heating system - the air inlet of the air / fluid heat pump 55 can be in flow connection with the outside air or the ambient air of the room or the building, and the air outlet 57 can open into the room or the building to direct the warm air 56, 15 into it.

[0065] The in Figure 8 The illustrated embodiment corresponds to the embodiment from Figure 6 with an air / fluid heat pump 55 and in particular an air / water heat pump, as used in conjunction with the embodiment shown in Figure 7as described above. The entire fluid flow 47 flowing from the fluid storage tank 35 to the air / fluid heat pump 55 is directed as the first fluid flow 14 in the air / fluid heat pump 55 to the cold fluid outlet 12. The second fluid flow 15 is here as in the embodiment described above. Figure 7 an airflow 56. The airflow 56 can also be guided here as in connection with the embodiment of Figure 7 described.

[0066] The in Figure 9 The illustrated embodiment is a possible circuit configuration for summer operation of an arrangement according to the invention, which in winter operation heats a building and warms the domestic hot water, and in summer operation continues to warm the domestic hot water and can supply a cooling circuit 58. For the sake of clarity, the at least one heat exchanger 3, which belongs to the heating system and is, for example, located in Figure 8 is shown in Figure 9 not shown.

[0067] In the embodiment according to Figure 9 A cooling circuit 58 with a heat exchanger 59 is connected to the first fluid inlet 10 and the cold fluid outlet 12 of the fluid / fluid heat pump 4. The fluid flow 60 exiting the cold fluid outlet 12 can, for example, have a temperature in the range of 5°C to 9°C or from 16°C to 20°C, and the returning fluid flow 61 entering the first fluid inlet 10 of the fluid / fluid heat pump 4 can have a temperature in the range of 10°C to 14°C or from 21°C to 25°C.

[0068] A second fluid storage tank 62 can optionally be connected to the cooling circuit 58. The fluid flows 60, 62 from the fluid / fluid heat pump 4 and the heat exchanger 59 enter this tank, and the fluid flows 63, 61 flowing to the heat exchanger 59 and the fluid / fluid heat pump 4 exit from it. For the supply flow 60, 63, a first fluid inlet 64 and a first fluid outlet 67 are located at the bottom of the second fluid storage tank 62. For the return flow 62, 61, a second fluid inlet 66 and a second fluid outlet 65 are located at the top of the second fluid storage tank 62, since cold fluid sinks and warm fluid rises, and therefore the fluid temperature is lower at the bottom than at the top.

[0069] The CO2 heat pump 2, the second fluid inlet 11 and the hot fluid outlet 13 of the fluid / fluid heat pump 4 as well as the (first) fluid storage tank 35 together with two heat exchangers 29a, 29b, which are part of a domestic hot water circuit 32, form a fluid circuit for heating the domestic hot water.

[0070] The fluid accumulator 35 corresponds to a fluid accumulator as described in the embodiments described in the Figures 4 , 5 , 6 and 8 has been described.

[0071] The fluid outlet 7 of the CO₂ heat pump 2 is connected to a first fluid inlet 41 of the second section 37 of the fluid storage tank 35. The fluid inlet 6 of the CO₂ heat pump 2 is connected to a fluid outlet 40 of the first section 36 of the fluid storage tank.

[0072] The second fluid inlet 11 of the fluid / fluid heat pump 4 is connected to the fluid outlet 46 of the third section 38 of the fluid storage tank 35 and the hot fluid outlet 13 of the fluid / fluid heat pump 4 is connected to the second fluid inlet 42 of the second section 37 of the fluid storage tank 35.

[0073] The two heat exchangers 29a, 29b are connected in parallel, with the fluid outlet 53 of the second section 37 of the fluid reservoir 35 connected to both the fluid inlet 30, 68 of the first heat exchanger 29a and the fluid inlet 69 of the second heat exchanger 29b. The fluid outlet 71 on the fluid side of the second heat exchanger 29b is connected to the fluid inlet 45 of the third section 38 of the fluid reservoir 35, whereas the fluid outlet 31, 70 on the fluid side of the first heat exchanger 29a is connected to the fluid inlet 54 of the first section 36 of the fluid reservoir 35.

[0074] On the domestic hot water side, the water outlet 72 of the first heat exchanger 29a and the water outlet 73 of the second heat exchanger 29b are connected to the same water supply 74 of the domestic hot water circuit 32. The water inlet 76 of the second heat exchanger 29b is connected to the hot domestic hot water return 77, whereas the water inlet 75 of the first heat exchanger 29a is connected to the cold domestic hot water return 78.

[0075] In this way, the domestic hot water is heated and the air conditioning system is supplied with cooled fluid at the same time.

Claims

1. An assembly for heat generation, comprising a CO2 heat pump (2) which includes a fluid inlet (6) and a fluid outlet (7) and for which a maximum fluid inlet temperature is specified, a heat exchanger (3) which includes a fluid inlet (8) and a fluid outlet (9) and whose fluid outlet temperature is higher than the maximum fluid inlet temperature of the CO2 heat pump (2), and comprising a fluid / fluid heat pump (4) which includes a first and a second fluid inlet (10, 11) and a cold fluid outlet (12) and a warm fluid outlet (13), wherein the fluid / fluid heat pump (4) is adapted to supply a first fluid stream (14) entering through the first fluid inlet (10) to the cold fluid outlet (12) and to supply a second fluid stream (15) entering through the second fluid inlet (11) to the warm fluid outlet (13) and thereby withdraw heat from the first fluid stream (14) and pass the same on to the second fluid stream (15), wherein the CO2 heat pump (2), the heat exchanger (3) and the fluid / fluid heat pump (4) can be connected in series in this order in a fluid circuit (5), wherein a fluid flows through the fluid circuit, the fluid outlet (9) of the heat exchanger (3) is in flow connection with the first fluid inlet (10) of the fluid / fluid heat pump (4), the fluid / fluid heat pump (4) is adapted to cool the first fluid stream (14) to a temperature which at most is equal to the maximum fluid inlet temperature specified for the CO2 heat pump (2), and the cold fluid outlet (12) of the fluid / fluid heat pump (4) is in flow connection with the fluid inlet (6) of the CO2 heat pump (2), furthermore comprising a fluid reservoir (35) which includes a first region (36) for storing fluid with a first temperature, a second region (37) for storing fluid with a second temperature, which is higher than the first temperature, and a third region (38) for storing fluid whose temperature lies between the first and the second temperature, wherein each of the three regions includes at least one fluid inlet and at least one fluid outlet, and a fluid inlet (41) of the second region (37) is in flow connection with the fluid outlet (7) of the CO2 heat pump (2), characterized in that a fluid inlet (39) of the first region (36) is in flow connection with the cold fluid outlet (12) of the fluid / fluid heat pump (4) and a fluid outlet (40) of the first region (36) is in flow connection with the fluid inlet (6) of the CO2 heat pump (2), and a fluid outlet (43) of the second region (37) is in flow connection with the fluid inlet (8) of the heat exchanger (3), and a fluid inlet (45) of the third region (38) is in flow connection with the fluid outlet (9) of the heat exchanger (3) and a fluid outlet (46) of the third region (38) is in flow connection with the first fluid inlet (10) of the fluid / fluid heat pump (4).

2. The assembly according to claim 1, characterized in that the circuit fluid stream is split between heat exchanger (3) and fluid / fluid heat pump (4) and a first partial stream enters the first fluid inlet (10) as a first fluid stream (14) and a second partial stream enters the second fluid inlet (11) as a second fluid stream (15), and after exit from the warm fluid outlet (13) the second fluid stream (15) flows into the fluid stream (19) from the CO2 heat pump (2) to the heat exchanger (3).

3. The assembly according to claim 1, characterized in that the second fluid inlet (11) and the warm fluid outlet (13) of the fluid / fluid heat pump (4) form part of a second fluid circuit (27) which includes a further heat exchanger (28).

4. The assembly according to any of the preceding claims, characterized in that the second region (37) of the fluid reservoir (35) includes a second fluid inlet (42) and the same is in flow connection with the warm fluid outlet (13) of the fluid / fluid heat pump (4) or after exit from the warm fluid outlet (13) of the fluid / fluid heat pump (4) the second fluid stream (15) flows into the fluid stream (19) from the CO2 heat pump (2) to the fluid reservoir (35).

5. The assembly according to any of the preceding claims, characterized by a second heat exchanger (29) with a fluid inlet (30) and a fluid outlet (31), wherein the second region (37) of the fluid reservoir (35) includes a second fluid outlet (53) which is in flow connection with the fluid inlet (30) of the second heat exchanger (29), and the first and / or third region (36, 38) of the fluid reservoir (35) includes a second fluid inlet (54) which is in flow connection with the fluid outlet (31) of the second heat exchanger (29).

6. The assembly according to any of the preceding claims, characterized in that the fluid reservoir (35) is a stratified reservoir with high stratification and includes at least three layers, wherein the bottommost layer corresponds to the first region (36) and the uppermost layer corresponds to the second region (37) and the middle layer corresponds to the third region (38).

7. The assembly according to any of the preceding claims, characterized in that the fluid circulating in the fluid circuit (5) is water.

8. The assembly according to any of the preceding claims, characterized in that the first heat exchanger (3) forms part of a room or building heater.

9. The assembly according to claim 5 and 8, characterized in that the second heat exchanger (29) forms part of a service water circuit (32).

10. The assembly according to any of the preceding claims, characterized in that the temperature difference between the fluid entering the CO2 heat pump (2) and the fluid exiting from the same is at least 20 °C and preferably lies in the range of 40 °C to 85 °C and particularly preferably in the range of 45 °C to 70 °C.

11. The assembly according to claim 10, characterized in that the temperature of the fluid entering the CO2 heat pump (2) is not more than 30 °C and preferably lies in the range of 2 °C to 25 °C and particularly preferably in the range of 5 °C to 20 °C.

12. The assembly according to claims 10 to 11, characterized in that the temperature of the fluid exiting from the CO2 heat pump (2) is at least 50 °C and preferably lies in the range of 55 °C to 95 °C and particularly preferably in the range of 60 °C to 90 °C.

13. The assembly according to any of claims 1, 3, 5, 6, 8 to 12, each not in conjunction with claim 2, characterized in that the fluid circulating in the fluid circuit (5) is water and the fluid / fluid heat pump (4) is an air / water heat pump, wherein the second fluid stream (15) is an air stream (56).

14. The assembly according to claims 13 and 8, characterized in that the second fluid inlet (11) of the air / water heat pump is in flow connection with the ambient air of the room or the building and the warm fluid outlet (13, 57) of the air / water heat pump opens into the room or the building.

15. The assembly according to any of claims 1 to 4, 6 to 12, each in conjunction with claim 5, characterized in that the cold fluid outlet (12) of the fluid / fluid heat pump (4) can be connected to the feed line (60, 63) of a cooling circuit (58) and the first fluid inlet (10) of the fluid / fluid heat pump (4) can be connected to the return line (62, 61) of the cooling circuit (58), and the fluid inlet (6) of the CO2 heat pump (2) can be connected to the fluid outlet (40) of the first region (36) of the fluid reservoir (35), and the first region (36) of the fluid reservoir (35) includes a second fluid inlet (54) which is in flow connection with the fluid outlet (31, 70) of the second heat exchanger (29, 29a).