Hot Water Station

Abstract

A hot water station (50, 51, 52) for providing hot drinking water, a water inlet (55) to which a hot water pipe can be connected; a water outlet (57) for providing hot water, to which a pipe or fitting can be connected; a water tank (60) connected between the water inlet (55) and the water outlet (57) and designed to store water; and The water tank (60) a primary circuit (100) designed for the water to flow through; a secondary circuit (200) having a phase change material designed to store thermal energy as latent heat from hot water in the primary circuit (100) and release the thermal energy stored as latent heat to cold water in the primary circuit (100); a heat exchanger (64) having Hot water stations (50, 51, 52).

Description

[Technical Field]

[0001] The present invention relates to a hot water station for providing hot drinking water. [Background technology]

[0002] Hot water stations are used in hot water installations for the provision and distribution of hot water. A typical hot water installation includes a drinking water heater having a hot water tank for heated water, and one or more brewing stations through which the hot water from the drinking water heater flows through a piping system. The hot water station is typically used as a hot water transfer point between the piping from the drinking water heater and the piping to the brewing station for drinking water.

[0003] Long piping paths mean that the provision of hot water from the drinking water heater at the brewing station can take a considerable amount of time. If water is not brewed for a relatively long time, the water remains in the piping system and cools. This cold water must first drain before hot water is again available at the brewing station. Water that remains in the piping system for a relatively long period of time can cause hygiene problems, as waterborne bacteria, such as Legionella, can rapidly multiply.

[0004] In conventional piping systems with long piping paths, circulation piping is provided for comfort and hygiene reasons. This allows hot water to circulate through the piping system, thereby constantly flowing past or near the brewing station, resulting in hot water being available at the brewing station immediately or after a short time. If the temperature of the circulating hot water is high enough, bacteria in the water are killed, thereby reducing hygiene issues. However, circulation requires a pump, which consumes as much energy as heating the circulating hot water. Constantly heating circulating drinking water to approximately 60°C, ideally for a short time, is expensive and involves heat losses and electrical costs. Non-circulating hot water systems are more energy-efficient, eliminating circulation piping. For hygiene reasons, the volume of the piping path between the drinking water heater and the brewing site should be small so that little water remains in the piping. The maximum volume of the piping path may be regulated by law or construction. If the volume of the piping between the drinking water heater and at least one of the extraction points is greater than 3 liters, then for hygiene reasons and in accordance with legal regulations in Germany, a circulation piping or a temperature-maintaining band is mandatory.

[0005] Furthermore, hot water installations without circulation piping result in reduced comfort: if the water in the piping is already cooled, the water must first flow out at the brewing station before hot water from the drinking water heater becomes available at the brewing station some time later.

[0006] Patent document 1 discloses a device for heating cold water in a pipe between a hot water production facility and a hot water tap. Energy is stored in a heat accumulator as latent heat, i.e., transfer enthalpy. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] German Utility Model No. 29503746 Summary of the Invention [Problem to be solved by the invention]

[0008] The problem is to provide a device that is more comfortable when extracting hot water. [Means for solving the problem]

[0009] The problem is solved by a hot water station having the features of claim 1.

[0010] A hot water station for providing hot drinking water has a water inlet to which a hot water pipe can be connected, a water outlet to which a pipe or fitting can be connected for providing the hot water, and a water tank connected between the water inlet and the water outlet and designed to store water. The water tank includes a heat exchanger having a primary circuit designed to have water flow through it, and a secondary circuit having a phase change material designed to store thermal energy as latent heat from the water in the primary circuit and release the thermal energy stored as latent heat to the water in the primary circuit.

[0011] Hot water is heated drinking water or water for use, usually in the temperature range of 30°C to 60°C, especially 45°C to 60°C. Heated water is also referred to as hot water in the following. The cooled formerly hot water in a hot water system is also referred to as cold water. It may be cooled to ambient temperature. The thermal energy of the hot water, which has a temperature higher than the melting temperature of the phase change material, is stored in the phase change material as latent energy. The stored latent heat is transferred to and heats the cold water, which has a temperature lower than the melting temperature of the phase change material.

[0012] The hot water station can be advantageously used in hot water installations without a circulation line. It stores the hot water decentrally and is located closer to the extraction site than the hot water tank of the drinking water heater, so that the time until hot water is available at the extraction station is reduced. Nevertheless, its use in hot water installations with a circulation line is also possible, since in this case too the time until hot water is available at the extraction station is reduced.

[0013] In one embodiment, the hot water station is a hot water transfer point and is connected via at least one supply pipe to a drinking water heater that supplies the hot water station. At least one distribution pipe leads from the hot water station to the extraction site. The hot water station is provided with a water inlet and a water outlet for connecting these pipes. A hot water pipe can be installed at the water inlet, but cold water, for example, cooled in the pipe, can also flow into the hot water station's water tank through the pipe. Even if the heating function of the drinking water heater fails, only cold water will be available. Water is provided through the water outlet. Although hot water should be provided, there are operating conditions in which cold water is first discharged at a temperature lower than the desired discharge temperature. This is particularly true when starting up the hot water station and after a long period of brewing inactivity. The water outlet is provided with one or more distribution pipes to one or more extraction sites. For example, the installation of a tap fitting is also conceivable.

[0014] The water tank of the hot water station functions as a distribution buffer in the hot water installation, providing hot water closer to the extraction station. Advantageously, the water tank is used to store hot water. Nevertheless, there are operating conditions that include cold water that has cooled in the tank or entered as cold water through the water inlet. In one embodiment, the water tank has a volume of 10 liters or less, in particular a volume of 5 liters or less. The water tank can be bypassed through a bypass valve if it already contains enough hot water. However, the regular flow of hot water also advantageously results in a regular filling of the phase change material, which acts as a heat reservoir.

[0015] The heat exchanger allows the transfer of thermal energy between substances in the primary and secondary circuits without mixing of the materials. The components separating the substances advantageously have good thermal conductivity and a large surface area. The water flowing through the hot water station flows through the primary circuit.

[0016] The heat exchanger comprises a phase change material, abbreviated as "PCM" (English: phase change material). The secondary circuit comprises a phase change material that stores a large part of the thermal energy supplied from the primary circuit in the form of latent heat during the phase change. In one embodiment, the heat exchanger is operated with a phase change from solid to liquid phase and vice versa. Since no material in the secondary circuit flows in or out, the heat exchanger can also be called a (latent) heat store.

[0017] Flowing and / or stored hot water, which has a temperature higher than the melting temperature of the phase change material, causes a phase change in the phase change material, so that the melted phase change material stores part of the heat energy of the hot water during the phase transition. Nevertheless, especially in the case of flowing hot water, water with a temperature still sufficient for hot water is available at the extraction station. The phase change material may, for example, be waxy in its solid state and can be liquefied by the application of heat. The phase change material may, for example, contain brine salt, salt, or organic substances such as paraffins and fatty acids. If water extraction is not performed for a relatively long period of time, the heat stored in the phase change material is used to reheat the water that has cooled below its melting temperature upon solidification of the phase change material. The phase change material solidifies and releases the released heat energy back into the stored water.

[0018] Advantageously, the melting temperature of the phase change material is higher than a predetermined minimum discharge temperature of the discharged hot water. The minimum discharge temperature describes the desired operating parameters. The minimum discharge temperature depends on the requirements for domestic hot water use and does not necessarily have to be perceived as hot by the user, but may be perceived as lukewarm. An exemplary minimum discharge temperature is approximately 40°C. A typical predetermined discharge temperature range for the discharged hot water is 40-60°C, particularly 45-60°C, which is sufficient for domestic hot water use. The hot water flowing into the water inlet is also advantageously within this temperature range. The melting temperature of the phase change material is advantageously 40-50°C, particularly 42-48°C, so that the incoming hot water melts the phase change material. The same applies to the water heated in the hot water station. The phase transition during solidification occurs in the region of the desired release temperature range, particularly in the region above the minimum release temperature, so that water cooled in the primary circuit or incoming cold water causes the phase change material to solidify and fill the secondary circuit, which prevents cooling or heats the cold water.

[0019] In one embodiment, the hot water station is designed to electrically heat stored water. The hot water heated by the hot water station can have the same temperature range as the hot water provided by the hot water tank, although it is also contemplated that the hot water station may heat the water to a higher temperature, for example, 60°C.

[0020] Electrical heating can assist in the supply of hot water by reheating the stored water to prevent cooling after it has cooled below a predetermined threshold, e.g., a minimum discharge temperature, so that hot water is always available in the water tank for extraction. This can be repeated multiple times, requiring significantly less energy than would be required without the phase change material. Heating for a set time, e.g., in the morning, results in hot water being available when it is typically needed. The above-described interaction between hot water and the phase change material also occurs when water is electrically heated in the water tank. The thermal energy added to the water in this way is also stored in the heat exchanger.

[0021] One embodiment of the electric heating device for heating is designed to heat stored water that has cooled in the water tank or that has entered the water tank as cold water. The incoming cold water may be cooled in the pipes or may come from a broken drinking water heater. The stored water is advantageously electrically heated to a temperature of at least 55°C, in particular at least 60°C, so that it is available and / or stored as hot water.

[0022] In one embodiment, the water tank includes insulation that slows the cooling of the stored hot water. The insulation is also referred to as thermal insulation. The insulation can be configured to ensure that the hot water remains sufficiently warm, i.e., warmer than a predetermined minimum discharge temperature, for at least 24 hours. Particularly in conjunction with conventional electric heating, the hot water remains sufficiently warm for discharge. The insulation can be located on the outside of the water tank and can include thermal insulating material.

[0023] In one embodiment of the heat exchanger, multiple primary circuits are provided that are thermally coupled to a secondary circuit. For example, first and second primary circuits can be provided that are isolated from each other, so that no water exchange occurs between the two primary circuits. Each primary circuit can transfer thermal energy to the secondary circuit, so that the phase change material melts and the thermal energy from the secondary circuit can be transferred to the primary circuit upon solidification. The secondary circuits are designed to store thermal energy as latent heat from the hot water in the first and / or second primary circuits and release the stored thermal energy as latent heat to the cold water in the first and / or second primary circuits. This concept is not limited to two primary circuits; more than two primary circuits can be provided that are thermally coupled to the same secondary circuit.

[0024] An embodiment of a hot water station with two primary circuits in a heat exchanger combines the functionality of two hot water stations, since it provides drinking water for two hot water branches, for example for the bathroom and kitchen of a single residence. For example, a long shower process with hot water extraction in one hot water branch leads to the accumulation of thermal energy in the heat exchanger, which is then released for hot water extraction in the kitchen in the other hot water branch. This embodiment provides a further efficiency improvement, since the hot water extraction from one of the primary circuits thermally charges the phase change material acting as a heat store, and this charged energy store becomes available for the other primary circuit.

[0025] In one embodiment, the heat exchanger is designed as a plate heat exchanger. Alternatively, it may comprise finned tubes or an aluminum body with a particularly large surface area, which allows for a large degree of freedom in the design of the heat exchanger. Alternatively, in one embodiment, one or more, in particular two, hollow cylindrical chambers with phase change material may be provided for the secondary circuit, and one or more, in particular two, hollow cylindrical water chambers may be provided for the primary circuit. The chambers for the primary and secondary circuits are arranged alternately, with the hollow cylindrical chambers being arranged interdigitated with one another.

[0026] The hot water station may be provided with a pressure regulator to reduce the pressure of the incoming water at the water inlet if the water is provided at high pressure. High pressure is used in hot water installations to bypass long pipe runs with small cross-sections and no circulation pipes. The operating pressure of one embodiment of the hot water station is permanently in the range of 6 bar, with pressure surges of up to 10 bar possible.

[0027] In one embodiment, the water tank is designed as a small water tank with a storage capacity of 2 liters or less, particularly 1 liter or less, and particularly 0.5 liters or less. With such a water tank, the hot water station is used not as a transfer point but as a micro-storage station for providing hot water in close proximity to the brewing station. The micro-storage station is a compact, small hot water station designed, for example, as an under-counter hot water station for installation under a sink. The less water is stored, the more compact it becomes. In hot water installations, the optional micro-storage station increases comfort in terms of hot water preparation time, which is again reduced by a few seconds.

[0028] The micro-storage station advantageously includes insulation to slow the cooling of the water. Advantageously, a heating device is also provided within the micro-storage station.

[0029] In the following, some embodiments will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0030] [Figure 1] 1 shows a schematic representation of an embodiment of a hot water installation. [Figure 2] 1 shows a schematic representation of an embodiment of a hot water station. [Figure 3] 1A and 1B show schematic cross-sectional views of examples of heat exchangers; [Figure 4] 10 shows a schematic cross-sectional view of another embodiment of a heat exchanger. [Figure 5] 1 shows a schematic representation of another embodiment of a hot water installation. [Figure 6] 1 shows a schematic representation of another embodiment of a hot water station. [Figure 7] 10 shows a schematic cross-sectional view of yet another embodiment of a heat exchanger; [Figure 8] 10 shows a schematic cross-sectional view of yet another embodiment of a heat exchanger; [Figure 9] 1 is a three-dimensional representation of another embodiment of a hot water station. [Figure 10] A three-dimensional representation of the pedestal area of ​​the hot water station. [Figure 11] 1 is a schematic representation of the head area of ​​a hot water station. [Figure 12] A three-dimensional representation of the head area of ​​a hot water station. [Figure 13] FIG. 1 is a cross-sectional view of a hot water station. DETAILED DESCRIPTION OF THE INVENTION

[0031] In the drawings, identical or functionally similar components are designated by the same reference numerals.

[0032] 1 shows a schematic diagram of an embodiment of a hot water installation with two hot water stations 51, 52. The hot water installation includes a drinking water heater 1 with a hot water tank 3, exemplarily first and second hot water stations 51, 52, and four brewing stations 71, 72, 73, 74. The drinking water heater 1 heats cold drinking water that flows into the hot water tank 3 via a house connection 21 and stores it in the hot water tank 3 for brewing. A typical temperature of the hot water in the hot water tank 3 is 52°C. Heating is exemplarily performed by a heat pump heat exchanger or a gas heater, but is not limited to these heating means.

[0033] Between the drinking water heater 1 and the brewing stations 71, 72, 73, 74, a piping system 9 without a circulation pipe is provided, which is designed to allow hot water to flow from the hot water tank 3 of the drinking water heater 1 to the brewing stations 71, 72, 73, 74. In the brewing stations 71, 72, 73, 74, the hot water is extracted and can flow out of the hot water installation. The brewing stations 71, 72, 73, 74 can be designed, for example, as showers or taps. Two of the brewing stations 71, 72 and 73, 74 are each connected to one of the hot water stations 51, 52, so that water flows from the drinking water heater 1 through the first or second hot water station 51, 52 to the brewing stations 71, 72 and 73, 74.

[0034] The hot water stations 51, 52 are hot water transfer points and are each connected to the drinking water heater 1 via a supply pipe 11. From the hot water stations 51, 52, a distribution pipe 13 leads to the brewing stations 71, 72, 73, 74. The hot water stations 51, 52 may be provided with multiple connections for the distribution pipes 13 leading to the brewing stations 71, 72, 73, 74. As shown in FIG. 1, multiple brewing stations are advantageously installed in a row, so that the distribution pipe 13 to the most distant brewing station 72, 74 is looped by another brewing station 72, 74. The piping volume in the piping of each piping path from the drinking water heater 1 to one of the brewing stations 71, 72, 73, 74 is less than or equal to a predetermined maximum piping volume. This embodiment of the hot water installation is a small installation within the meaning of the German Drinking Water Ordinance, in which the maximum piping volume of each piping path must be less than or equal to 3 liters. Furthermore, the volume of the drinking water tank in the system must not exceed 400 litres. In contrast to larger installations, there is no mandatory annual microbiological drinking water testing for such small installations.

[0035] A hot water installation with two hot water stations 51, 52 can be provided, for example, for two small dwellings, with one hot water station 51, 52 arranged for each. For a dwelling for two people, one hot water station for the kitchen and the extraction points for the bathroom is sufficient. Alternatively, the hot water installation can be provided for a larger dwelling for three or four people. In that case, one hot water station 51, 52 each is provided for the bathroom and kitchen and their extraction points.

[0036] For example, in the case of a hot water installation for several dwelling units in a multifamily building or apartment complex, more than two hot water stations 51, 52 are provided, in which case the hot water installation is preferably a small installation without a circulation pipe, which can be achieved by high water pressure and small pipe cross-sections even in multifamily housing complexes with long pipe runs.

[0037] In this embodiment, two hot water branches 10, 20 are provided, in which water is conducted through a supply pipe 11 and one or more distribution pipes 13 to one or more brewing stations 71, 72 or 73, 74. In each hot water branch 10, 20, water flows through one of the hot water stations 51, 52. On the one hand, hot water from the drinking water heater 1 is conducted to the first and second brewing stations 71, 72 in the first hot water branch 10, and on the other hand, hot water from the drinking water heater 1 is conducted to the third and fourth brewing stations 73, 74 in the second hot water branch 20. The hot water branches 10, 20 are separated to prevent water exchange. They have separate supply pipes 11 and separate distribution pipes 13. In each of the hot water branches 10, 20, the piping volume within the piping of the piping path is less than a predetermined maximum piping volume of 3 liters. The cold water is led separately and separated from the hot water installation via a cold water pipe 19 to the extraction stations 71, 72, 73, 74.

[0038] The hot drinking water from the drinking water heater 1 that flows into the supply pipes 11 and distribution pipes 13 during brewing but is no longer brewed is cooled. At the time of the next brewing, this cooled water must first flow out until hot water from the drinking water heater 1 is again available at the brewing stations 71, 72, 73, 74. The hot water stations 51, 52 store hot water and can advantageously also heat cold water, thereby reducing the time until hot water is available at the brewing stations.

[0039] Figure 2 shows a schematic structure of an example of a hot water station 51, as may be used in the exemplary hot water installation of Figure 1 as the first and second hot water stations 51, 52. However, their use is not limited to such hot water installations.

[0040] The hot water station 51 has a water inlet 55 connected to the water supply pipe 11 and a water outlet 57 connected to the distribution pipe 13 so that the hot water branch 10 extends through the hot water station 51. Arrows indicate the incoming water 111 and the outgoing water 131.

[0041] In this embodiment, if water is provided at high pressure, an optional pressure regulator 31 is provided on the inlet side to reduce the pressure of the incoming water at the water inlet 55. High pressures can be used in hot water installations to bypass long piping runs without circulation piping with small cross sections. In other embodiments, a pressure regulator can be connected upstream of the water inlet 31 if necessary.

[0042] The hot water station 51 includes a water tank 60 designed to store water. To distinguish it from the large hot water tank 3 of the drinking water heater 1, this water tank 60 may also be referred to as a small hot water tank for clarity. The storage volume of the water tank 60 is smaller than that of the hot water tank 3 in the drinking water heater 1. A typical value is 5 liters. The storage volume of the water tank 60 is not counted in the piping volume of a hot water installation, which must be smaller than the maximum volume. However, the total volume of all tanks for water in the system must be less than the maximum storage volume, i.e., 400 liters, so that the hot water installation is considered a small installation according to the German Drinking Water Ordinance.

[0043] The water tank 60 includes insulation 62 that significantly slows the cooling of the stored hot water. Such insulation 62 is located on the outside of the water tank 60. It may include a thermally insulating, heat-storing material.

[0044] The water tank 60 is designed to electrically heat water. If cold water is present in the water tank 60, it can be electrically heated as cold water from the pipe or as it is cold. This allows hot water to be available in the water tank 60 even if no extraction is performed for a relatively long time. For example, in one embodiment, heating to 60°C is contemplated after a relatively long rest period. Heating can be performed, for example, as soon as the temperature of the stored water falls below a predetermined threshold, such as a predetermined minimum discharge temperature, until the temperature in the water tank 60 rises above another predetermined threshold. This process can be repeated if the water temperature drops again. For heating, a heating element 66 is provided as a heating device, which can have a power consumption of, for example, 100 watts. This value is significantly lower than the power consumption of instantaneous water heaters for heating water in the station.

[0045] The water tank 60 includes a heat exchanger 64 with a primary circuit for potable water and a secondary circuit containing a phase change material (abbreviated as PCM). Exemplary examples of the heat exchanger 64 are a plate heat exchanger, a finned tube heat exchanger, or a heat exchanger with a large surface area aluminum body. The phase change material stores a large portion of the thermal energy from the primary circuit supplied to it in the form of latent heat absorbed during the phase change from solid to liquid. The latent heat is also referred to as transition enthalpy, and in this example, the sublimation and fusion enthalpies are relevant. The phase change can occur at a melting temperature of approximately 45°C. The phase change material can include, for example, hydrated salts, salts, or organic substances such as paraffins and fatty acids. The phase change occurs just below or within the desired discharge temperature range of the hot water to be discharged. Hot water flowing through and / or electrically heated by the hot water station induces a phase change in the phase change material, storing a portion of the hot water's thermal energy. Nevertheless, even during hot water extraction, in which the thermal energy is partly used for the phase change, sufficient hot water is provided at the extraction stations 71, 72, 73, 74. If no extraction takes place for a relatively long time, the thermal energy stored in the phase change material contributes to preventing or slowing the cooling of the stored water. The phase change material solidifies when the water in the primary circuit is cold or cooled, and the thermal energy released is transferred to the stored or flowing water and heats it.

[0046] For example, water at about 50°C from the supply pipe 11 may cause a phase change in a phase change material that liquefies in this temperature range. Nevertheless, in the extraction stations 71, 72, 73, 74, hot water at about 40°C may be extracted despite the phase change.

[0047] The combination of the heat exchanger 64 with phase change material, the heating device 66, and the insulation 62 significantly reduces the energy demand for providing hot water near the brewing stations 71, 72, 73, and 74. Compared to an instantaneous water heater within the station, the energy demand for the hot water station 51 is reduced by approximately seven times. The insulation 62 can maintain the water temperature for at least 24 hours, so that hot water can be extracted without reheating. The hot water station 50 can provide hot water at the brewing stations 71, 72, 73, and 74 after only 8 to 15 seconds. Additionally, the lower pressure loss of the heat exchanger 64, designed as a plate heat exchanger, allows a discharge capacity of 15 liters per minute.

[0048] The hot water station 51 with the water tank 60 has exemplary dimensions of 540 x 300 x 82 mm. It weighs approximately 9 kg. It is provided with a 1 / 2" female threaded connection. For field installation of the transfer point, stainless steel internal piping with a 1 / 4" female threaded connection is provided. The piping is available in one embodiment as a raw or complete set. Alternatively, it can be already installed in the hot water station 51 at the time of shipment.

[0049] The hot water station 51 significantly reduces the time until hot water is available at the brew stations, and the optional mini storage stations 80 at the brew stations 71, 72, 73, 74 can further reduce the time until hot water is available.

[0050] FIG. 1 shows that the brew stations 71, 72, 73, and 74 in this embodiment of the hot water installation each include a micro-storage station 80 in which hot water can be stored in close proximity to the outlet flow from the brew stations 71, 72, 73, and 74, respectively. The micro-storage station 80 is a compact, small embodiment of a hot water station. It can be designed, for example, as an under-counter storage station. Such an under-counter storage station can be discreetly installed under a washbasin or in a shelf below the washbasin. The micro-storage station 80 can typically store up to 0.5 liters of water. The optional micro-storage station 80 increases comfort in terms of the time until hot water is available, which is reduced to less than 8 seconds; 5 seconds is a typical value.

[0051] The micro storage station 80 is constructed similarly to the hot water station 51 described in connection with FIG. 2, with a small water tank to provide hot water, and advantageously also with the other features described above, i.e., insulation and heating.

[0052] The micro-storage station 80 includes thermal insulation to slow the cooling of the water. Advantageously, the micro-storage station 80 also includes a heating device, e.g., with a heating element and a heat exchanger with a phase change material, the operation mode of which has been described above. The power consumption of the micro-storage station 80 is in the range of 50 watts.

[0053] The storage volume of micro-storage station 80 is not counted toward the piping volume, which must be less than a maximum of 3 liters because the hot water system is a small-scale system. The storage capacities of the water tanks in hot water stations 51, 52 and the micro-storage station are not part of the piping volume, so in this embodiment, they do not exceed the maximum piping volume. However, the storage volume of micro-storage station 80 is counted toward the total volume of all tanks in the system, which must be less than a maximum of 400 liters because it is a small-scale system.

[0054] The highly efficient in-line water tanks 60 in the hot water stations 51, 52, especially in combination with the optional micro storage station 80, allow for significantly shorter times to provide hot water at the brew stations 71, 72, 73, 74 than conventional hot water installations.

[0055] The hot water stations 51, 52 with the water tank 60 and the micro-storage station 80 consume very little electrical energy, especially compared to stations with instantaneous water heaters. The power consumption of the hot water stations 51, 52 with the optional micro-storage station 80 and the water tank 60 is almost negligible compared to the power consumption of stations with instantaneous water heaters. This advantage is particularly effective in large systems with many hot water stations 51, 52 and therefore many residential units. The low energy consumption, typically 50-100 watts, results in significantly lower total grid-tied power compared to conventional systems or systems with instantaneous water heaters within the stations. When multiple hot water stations 51, 52 are present, a concurrency lock to limit the number of hot water stations 51, 52 operating simultaneously is no longer required. A relatively small cable cross-section can be used for the power supply. No additional substations are required. This overall lower cost for power supply also translates into less planning effort for the system, especially for the power supply.

[0056] 3 shows a schematic cross-section of an embodiment of a heat exchanger 64 designed as a plate heat exchanger. Such a heat exchanger 64 can be installed in the hot water stations 51, 52 or in the micro-storage station 80. Between the plates, the phase change material of the secondary circuit 200 and the water of the primary circuit 100 are arranged alternately. Hot water with a temperature above the melting temperature of the phase change material releases thermal energy to the secondary circuit 200, which contains the phase change material in the solid phase, causing it to melt and storing the latent heat from the hot water in the molten phase change material. When cold water with a temperature below the melting temperature is present in the primary circuit 100, the thermal energy stored as latent heat in the phase change material is released to the cold water in the primary circuit 100 as the phase change material solidifies, heating it.

[0057] 4 shows a schematic cross-section of a heat exchanger 64 having exemplary finned tubes 92 through which water from a primary circuit 100 flows. The finned tubes 92 are provided on the outside with a phase change material in a secondary circuit 200. The finned tubes 92 are tubular components with fins 94 on their outer surfaces to increase the tube surface area. This improves the transfer of thermal energy between the inside and outside of the tubes. Advantageously, the finned tubes 92, and in particular the fins 94, are made of a material with good thermal conductivity.

[0058] The design of the heat exchanger 64 is not limited to the above-described embodiment. Good heat transfer, a large surface area over which thermal energy transfer occurs, and weight, given preferred wall mounting, also play a role in the design. For example, another embodiment of the heat exchanger 64 includes an aluminum body with a large surface area.

[0059] Figure 5 shows a schematic representation of another embodiment of a hot water installation. The following description will focus on the differences between the previous embodiment of Figure 1 and the hot water stations 51, 52 described in relation to Figures 2-4.

[0060] In this embodiment, two hot water branches 10, 20 are provided, on the one hand, hot water from the drinking water heater 1 is led to first and second brewing stations 71, 72 in the first hot water branch 10, and on the other hand, hot water from the drinking water heater 1 is led to third and fourth brewing stations 73, 74 in the second hot water branch 20. The hot water branches 10, 20 are separated so that no water exchange occurs, but both run through the same hot water station 50. They have separate supply pipes 11 and separate distribution pipes 13. The hot water branches 10, 20 are constructed with a loop installation and a micro-storage station 80, as in the previous embodiment.

[0061] In each of the hot water branches 10, 20, the piping volume within the piping of the piping path is equal to or less than a predetermined maximum piping volume of 3 liters.

[0062] The two hot water branches 10 , 20 extend through two primary circuits 100 , 102 of the heat exchanger 64 in the hot water station 50 .

[0063] FIG. 6 shows a schematic example of a hot water station 50 that can be used in the hot water installation described above.

[0064] The hot water station 50, like the previous embodiment, includes a water tank 60, insulation 62, a heat exchanger 64, and a heating element 66 as a heating device. Since the hot water station 50 is provided for the two hot water branches 10, 20, it has a double water inlet 55 for the supply pipe 11 and a double water outlet 57 as a connection for the distribution pipe 13. If there are more than two primary circuits, the fittings for the inlets and outlets are correspondingly multiplexed and can also be designed in the same way. Since the hot water station 50 stores more water to supply the two hot water branches 10, 20, the housing dimensions are also larger than those of the previous embodiment. An optional pressure regulator 31 is provided on the inlet side.

[0065] The first and second water inlets 55 are connected to supply pipes 11, and the first and second water outlets 57 are connected to distribution pipes 13. The inflow and outflow water 111, 131 of the first hot water branch 10 flows through the first water inlet 55 or water outlet 57, and the inflow and outflow water 112, 132 of the second hot water branch 20 flows through the second water inlet 55 or water outlet 57. There is no mixing of drinking water between the hot water branches 10, 20. There is also no mixing within the hot water station 50. In addition to the separate distribution pipes 13, the hot water branches 10, 20 also have separate supply pipes 11 extending between the drinking water heater 1 and the hot water station 50.

[0066] The secondary circuit of heat exchanger 64 contains a phase change material and interacts with both primary circuits, resulting in thermal coupling through the secondary circuits, since heat from each of the primary circuits can be stored in the secondary circuit and released from the secondary circuit to each of the primary circuits, allowing the phase change material to be charged through one of the primary circuits and then the stored thermal energy to be released to the other primary circuit.

[0067] 7 shows a schematic cross-section of a heat exchanger 64, exemplarily designed as a plate heat exchanger. Between the plates, the phase change material of the secondary circuit 200 and the water of the first and second hot water branches 10, 20 flowing through the first and second primary circuits 100, 102 are arranged alternately. However, the water of the first primary circuit 100 flows through the plates spatially separated from the water of the second primary circuit 102, preferably on alternately arranged flow paths, so that the water in the first primary circuit 100 flows past one side of the phase change material between two adjacent plates, and the water in the second primary circuit 102 flows past the other side. Thus, thermal energy stored in the phase change material can be transferred from the secondary circuit 200 to both the first and second primary circuits 100, 102, even if the accumulation of thermal energy is caused only by extraction in one of the primary circuits 100, 102. Nevertheless, both primary circuits 100, 102 may be filled with phase change material.

[0068] For example, a shower process in the first primary circuit 100, in which a lot of hot water is typically extracted over a relatively long time in the first hot water branch 10, causes a build-up of thermal energy in the secondary circuit 200. This energy can then be released via the second primary circuit 102 for water extraction in the second hot water branch 20 in the kitchen, but also for hand washing in a bathroom provided in the first hot water branch 10, for example.

[0069] 8 shows a schematic cross-section of an embodiment of a heat exchanger 64 having finned tubes 92 through which the water of the primary circuits 100, 102 flows. There are first and second finned tubes through which the water of the first or second primary circuits 100, 102 flows without fluid exchange. The tubes 92 are advantageously arranged in an alternating pattern, with a first tube adjacent to a second tube, or vice versa.

[0070] Other features and uses of the hot water station, namely, insulation and stored water heating, previously described in connection with Figures 1-4, are also provided in the hot water station 50 of Figures 5-8 to heat and slow the cooling of the water in the hot water station 50 for both hot water branches 10, 20. For example, insulation 62 may keep the water warm enough for brewing for up to 24 hours. In this embodiment, a 100-watt heating element 66 is also provided, allowing the chilled water in the water tank 60 to be heated to 60°C after a relatively long rest period.

[0071] The embodiment of the hot water station 50 described in connection with FIGS. 5-8 has the same advantages as the embodiment of the hot water stations 51, 52 described in connection with FIGS. 1-4. In both hot water branches 10, 20, the piping volume is each equal to or less than a predetermined value, in particular equal to or less than 3 liters. The discharge capacity of the extraction stations 71, 72, 73, 74 is greater than 20 liters / min in the hot water station 50, since the extraction stations 71, 72, 73, 74 are supplied via the two hot water branches 10, 20. The drinking water supply is more efficient, even though less energy is required. Planning and implementation of the hot water station 50 in a hot water installation is also simplified, since only one installation path is required instead of two if two hot water stations 51, 52 are provided for the two hot water branches 10, 20. Even if the hot water station 50 has the same or similar power consumption of 100W as the previous example, providing the thermal energy stored in the secondary circuit 200 to both primary circuits 100, 102 leads to improved efficiency.

[0072] 9 shows another embodiment of the hot water station 50. The hot water station 50 has an elongated basic shape with two support posts and a front fixing area 96 designed as a leg-shaped widening with a support surface. Through holes 97 in the fixing area 96, fixing means, for example screws, can be introduced to fix the hot water station 50, for example to a wall.

[0073] Inside the cylindrical main module 98, a heat exchanger with phase change material is provided, which is used to heat the chilled water in the chamber of the main module 98. A protective tube 99 is arranged longitudinally adjacent to the main module 98, inside which the electrical system and cables connecting the electrical components on both front sides run.

[0074] The hot water station 50 has a length of more than 1 meter, typically in the range of 1.5 meters.

[0075] The hot water station 50 has a first front area, also referred to as the base area 81, and a second, opposite front area, also referred to as the head area 82. In the base area 81, water enters from the drinking water heater 1 and exits the brewing stations 70, 71, 72, 73, and 74. The head area 82 is provided with connections for the supply, communication, and control of the electrical components. A heating device is also provided in the head area 82. It may be designed, for example, as a 50 W heater with a heating element. The heating device is used when the phase-change material is low in injection and refilling is insufficient. The sensor wiring runs through a protective tube 99 to a volumetric flow meter in the base area 81, which measures the water flow.

[0076] Despite the designation of the head and pedestal regions 82, 81, the orientation of the mounted hot water station 50 is not limited to the vertical orientation shown in Figure 9. The hot water station 50 may also be mounted upside down, horizontally, or at an angle, preferably in a flush mounting position.

[0077] 10 shows the base area 81 of the hot water station 50, with its water inlet and outlet, so that water inflow and outflow occur on the same front surface, which facilitates installation. At the water inlet 55, water flows from the drinking water heater and is directed into the inner water chamber 151. It flows through the inner water chamber 151 to the head area 82 of the hot water station 50, where it is diverted to the outer water chamber 512, through which it returns to the base area 81 and to the water outlet 57, which provides water for the brewing stations 70, 71, 72, 73, 74.

[0078] 11 shows a schematic diagram of the interior of hot water station 50 having a return chamber 84 in head region 82 of main module 98 through which water flows from inner water chamber 151 to outer water chamber 152. The height of return chamber 84 is in the range of 10 mm.

[0079] 12 shows the head region 82 of the main module 98 with an inlet opening 85 in the return chamber 84. Through the inlet opening 85, the main module 98 can be filled with phase change material. The inlet to the inner water chamber 151 and the outlet to the outer water chamber 151 are through an annular gap 86.

[0080] FIG. 13 shows a cross section of the hot water station 50, including the main module 98 and protective tube 99. The main module 98 contains two chambers filled with phase change material: an inner chamber 201 and an outer chamber 202, which function as secondary circuits, and inner and outer hollow cylindrical water chambers 151 and 152, which function as primary circuits. The inner water chamber 151 is located between the two chambers 201 and 202 containing phase change material 250. The chambers 201 and 202 containing phase change material 250 have aluminum walls and an internal structure 260 that allows for good heat transfer. The structure 260 has a cross section with radial webs that extend the surfaces of the chambers 201 and 202 and may be forked. The outer chamber is a vacuum chamber 270 for thermal insulation, which surrounds the chambers 201 and 202 containing phase change material 250 and the water chambers 151 and 152.

[0081] At the center of the inner chamber 201 containing the phase change material 250 is an electric heating element, which in one embodiment is about 200 mm long, located within or adjacent to the head region 82.

[0082] Chilled water from the pipes flows first through the inner water chamber 151 and then through the outer water chamber 152. As the water flows through the water chambers 151, 152, it absorbs the heat stored in the phase change material 250, so that when the water leaves the hot water station 50 it has a temperature of about 45°C. After the chilled water volume passes through the device and is heated by the phase change material 250 (which solidifies), hot water having a temperature of about 53°C flows from the hot water tank 3 and recharges the phase change material 250 by causing a phase change. If hot water is not extracted for a relatively long time, the phase change material 250 can be kept at temperature with little energy consumption and therefore does not solidify.

[0083] The features mentioned above and presented in the claims, as well as those which can be seen from the drawings, can be advantageously implemented individually and in various combinations. The invention is not limited to the described embodiments, but can be modified in various ways within the capabilities of those skilled in the art. [Explanation of symbols]

[0084] 1 Drinking water heater 3. Hot water tank 9 Piping System 11 Supply piping 10, 20 Hot water branch 13 Distribution piping 19 Chilled water piping 21 House connection 31 Pressure Regulator 50, 51, 52 Hot Water Stations 55 Water inlet 57 Water outlet 60 Water Tank 62 Insulation 64 Heat exchanger 66 Heating Element 70, 71, 72, 73, 74 Extraction Station 80 Micro Storage Station 81 Pedestal Area 82 Head Area 84 Reflux Chamber 85 Injection opening 86 Gap 92 Finned Tube 94 Finn 96 Fixed area 97 holes 98 Main Module 99 Protective tube 100, 102 Primary circuit 111, 112 Inflow water 131, 132 Runoff 151, 152 Water chamber 200 Secondary circuit 201, 202 Chambers 250 Phase Change Materials 260 Structure 270 Vacuum Chamber

Claims

1. A hot water station (50, 51, 52) for providing hot drinking water, comprising: a water inlet (55) to which a hot water pipe can be connected; a water outlet (57) for providing hot water, to which a pipe or fitting can be connected; a water tank (60) connected between the water inlet (55) and the water outlet (57) and designed to store water; and The water tank (60) a primary circuit (100) designed for the water to flow through; a secondary circuit (200) having a phase change material designed to store thermal energy as latent heat from the water in the primary circuit (100) and release the thermal energy stored as latent heat to the water in the primary circuit (100); a heat exchanger (64) having Hot water stations (50, 51, 52).

2. 2. The hot water station (50, 51, 52) of claim 1, wherein the melting temperature of the phase change material is higher than a predetermined minimum discharge temperature of the discharged hot water.

3. The hot water station (50, 51, 52) according to claim 1 or 2, wherein the predetermined discharge temperature range of the discharged hot water is 45 to 60°C.

4. Hot water station (50, 51, 52) according to claim 2, wherein the melting temperature of the phase change material is between 40 and 50°C, in particular between 42 and 48°C.

5. 3. A hot water station (50, 51, 52) according to claim 1 or 2, designed to electrically heat the stored water.

6. 3. A hot water station (50, 51, 52) according to claim 1 or 2, comprising an electric heating device (66) designed to heat stored water that has cooled in the water tank (60) or that has flowed into the water tank (60) as cold water.

7. 6. A hot water station (50, 51, 52) according to claim 5, designed to electrically heat the stored water to above 55°C, in particular above 60°C.

8. 3. The hot water station (50, 51, 52) according to claim 1 or 2, wherein the water tank (60) includes a thermal insulator (62) that retards cooling of the stored hot water.

9. 9. The hot water station (50, 51, 52) of claim 8, wherein the thermal insulation (62) comprises a thermally insulating material disposed on the exterior of the water tank (60).

10. 3. The hot water station (50, 51, 52) according to claim 1 or 2, wherein the primary circuit (100) is a first primary circuit (100) separated from a second primary circuit (102) of the heat exchanger (64).

11. The hot water station (50, 51, 52) of claim 10, wherein the secondary circuit (200) comprises one or more hollow cylindrical chambers (201, 202) having a phase change material, and the primary circuit (100) comprises one or more hollow cylindrical water chambers (151, 152) combined with each other.

12. 11. The hot water station (50, 51, 52) of claim 10, wherein the secondary circuit (200) is designed to store thermal energy as latent heat derived from water in the first and / or second primary circuits (100, 102) and to release the thermal energy stored as latent heat to the water in the first and / or second primary circuits (100, 102).

13. 3. A hot water station (50, 51, 52) according to claim 1 or 2, wherein the heat exchanger (64) is designed as a plate heat exchanger or comprises finned tubes (92) or comprises an aluminum body.

14. 3. A hot water station (50, 51, 52) according to claim 1 or 2, which is designed as a micro storage station (80), and the water tank (60) has a storage capacity of 2 liters or less, in particular a storage capacity of 1 liter or less, in particular a storage capacity of 0.5 liters or less.

15. 3. The hot water station (50, 51, 52) according to claim 1 or 2, wherein the hot water station is designed as an under-counter hot water station.

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