Hot water system

Abstract

The hot water supply system includes a potable water heater (1) having a hot water supply container (3), water discharge stations (70, 71, 72, 73, 74), and a circulating line-free line system (9) between the potable water heater (1) and the water discharge stations (70, 71, 72, 73, 74). The circulating line-free line system is designed so that heated drinking water flows from the potable water heater (1) to the water discharge stations (70, 71, 72, 73, 74) along a line path in the line system (9). The pressure in the line system and the pipe cross section of the line system depend on the length of the line path, so that the line volume of the line path is equal to or less than a predetermined maximum line volume. The line path includes a first section and a second section, and hot water supply stations (50, 51, 52) are provided in the line system (9) between the first section and the second section and are designed to heat and / or store drinking water.

Description

[Technical Field]

[0001] The present invention relates to a hot water supply system. [Background technology]

[0002] The hot water system includes a potable water heater having a hot water storage tank and one or more discharge stations through which hot water flows from the potable water heater through a line system. Summary of the Invention [Problem to be solved by the invention]

[0003] Long line paths mean that it takes a considerable amount of time to deliver hot water from the potable water heater to the dispensing station. When the water is not being dispensed, it remains in the line system and cools. Water that remains in the line system for a long time can cause hygiene problems as waterborne bacteria such as Legionella can rapidly multiply.

[0004] In conventional line systems with long line paths, a circulation line is conveniently provided to circulate hot water through the line system, thus always passing by or flowing near the water discharge station, making hot water available at the water discharge station immediately or after a short delay. If the temperature of the circulating hot water is high enough, bacteria in the water are killed, thus reducing hygiene issues. However, circulation requires a pump, which consumes a large amount of energy to heat the circulating hot water. Heating constantly circulating drinking water to approximately 60°C is complex, likely with only a short hot water discharge time between water withdrawals, and involves heat losses and electrical expenditures. Furthermore, in systems with a heat pump for heating, the largest heat pump-related losses occur at approximately 60°C. Circulating drinking water also mixes with the drinking water stored in the hot water supply container, which adversely affects the performance of the heat pump. These effects result in a loss of approximately 50% of the energy used.

[0005] If the volume of the line between the potable water heater and at least one outlet station exceeds 3 litres, a circulation line or temperature-controlled zone is mandatory for hygiene reasons according to German legal requirements.

[0006] According to the German drinking water regulations, a distinction is made between small and large systems. In a small system, the volume of the line between the drinking water heater and the discharge point is no more than 3 liters. Furthermore, the volume of the hot water container of the drinking water heater is no more than 400 liters. If these requirements are not met, the hot water system is a large system unless it is located in a one- or two-family home. In large systems in public or commercial buildings, including rental apartment buildings, annual microbiological drinking water testing must be carried out. This obligation does not apply to small systems.

[0007] CH 100 898 A shows a hot water system in which an insulated hot water container is provided between the water heater and the discharge station.

[0008] DE 41 39 288 A1 shows a water heater in which a continuous flow heater is provided between the water heater and the discharge station, which heater serves for disinfection and heating purposes.

[0009] DE 10 2011 122 639 A1 shows a water heater in which a continuous flow heater between the water heater and the water dispensing station is controlled in such a way that the water is not reheated when the water is drawn from the household appliance, but rather when the water is drawn manually.

[0010] AT 374 269 B shows a water heating device in which a distributor is provided between the water heater and the discharge station. If the temperature is below the minimum value, the water passes through a branch of the pipe to be heated.

[0011] DE 10 2014 225 693 A1 shows a water heating system in which a distributor is provided between the water heater and the discharge station. A parallel second line with an additional heat source can provide additional hot water if required.

[0012] DE 295 03 746 U1 shows a hot water generator with latent heat storage.

[0013] The problem is to provide an improved hot water system. [Means for solving the problem]

[0014] The object of the invention is achieved by a hot water supply system having the features of claim 1.

[0015] The hot water supply system includes a potable water heater having a hot water container, a water discharge station, and a circulating line-free line system between the potable water heater and the water discharge station, and is designed so that heated drinking water flows from the potable water heater to the water discharge station along a line path in the line system. The pressure in the line system and the pipe cross section of the line system depend on the length of the line path, and therefore the line volume of the line path is equal to or less than a predetermined maximum line volume. The line path has a first portion and a second portion, and the hot water supply station is provided between the first portion and the second portion and is designed to heat and / or store the drinking water.

[0016] The storage container is provided in particular for heated drinking water, whether from a drinking water heater or heated by a hot water station.

[0017] The hot water system is circulation-line-free, meaning there is no circulation line through which hot water constantly flows in a circular fashion. This saves energy. In systems with heat pumps, the effort to heat and circulate potable water is eliminated, so the lack of circulation saves approximately 50% of energy compared to systems with circulation lines. Furthermore, the heat pump can operate more efficiently due to the lack of mixing in the hot water tank. Advantageously, there is no freshwater station in the line system, which uses heat from a water-based central heating system for instant hot water heating, so the effort is lower compared to traditional hot water systems.

[0018] A potable water heater heats drinking water supplied to the inlet and stores the heated drinking water in a hot water container. The hot water typically has a temperature in the range of 45-60°C, especially 50-60°C, and can be drawn from a tap. Several outlet stations are provided within the hot water system. Examples of outlet points are taps and showers.

[0019] The line volume of a line path is the volume of the line in the line system through which water flows from the potable water heater to the dispensing station.

[0020] The pressure and pipe cross-section dimensions, especially the pipe inner diameter, depend on the specified maximum line volume between the drinking water heater and the discharge station and the line path length. The maximum line volume is small for hygiene reasons. Advantageously, the maximum line volume follows legal or construction specifications. Small systems within the meaning of the German Drinking Water Regulation, especially DVGW Worksheet W551, have a maximum line volume of 3 liters, so the mandatory annual microbiological drinking water test is not required for such systems.

[0021] In contrast to conventional hot water systems, where the line length of a pipe with a given cross-section is limited by a predetermined maximum line volume, in the hot water system according to the present invention, both the pipe cross-section and the pressure are adjusted to achieve the desired line length despite the predetermined maximum line volume. When adjusting the pipe cross-section, the pipe inner diameter is also adjusted. The longer the desired line length, the higher the pressure and the smaller the pipe cross-section, i.e., the pipe inner diameter. Higher pressure also means a higher flow rate, thus reducing deposits in the pipe and inhibiting bacterial growth. The length of the line path between the drinking water heater and the water discharge station is longer than in conventional hot water systems without a circulation line. The line path length is preferably longer than 25 m, particularly longer than 35 m, particularly longer than 45 m, and particularly longer than 65 m.

[0022] A hot water supply station is provided in the line system between the first and second sections, through which drinking water flows. The hot water supply station is designed to heat and / or store the hot water supplied to the inlet side. If previously heated drinking water remains in the line path for a long time because the hot water has not been dispensed, the water can be cooled and reheated by the hot water supply station before being dispensed. Additionally or alternatively, hot water can be temporarily stored in the hot water supply station and dispensed from there. This hot water can flow from a hot water supply container in the hot water supply station or can be heated within the hot water supply station. The hot water heated by the hot water supply station can have the same temperature range as the hot water supplied by the hot water supply container. However, preferably, the hot water supply station heats the water to a higher temperature, for example, 60°C. Preheating and / or intermediate storage by the hot water supply station improves comfort because hot water is available at the discharge point more quickly than if a hot water supply station were not provided and cold water had to be first drained from the line. A hot water station is a hot water transfer point between the supply line from a potable water heater and the individual pipes to the discharge point, which is formed by the distribution line between the hot water station and the discharge point. The first part of the line path is the supply line. The second part is the distribution line between the hot water station and the discharge point. The hot water station has connections for the distribution lines and therefore supplies the hot water branches. In small housing units, hot water branches are usually provided for the kitchen and bathroom. In larger housing units, two hot water branches are often provided, one for the kitchen and the other for the bathroom.

[0023] Optimization of pressure and pipe cross section can be focused on one of the sections. When focusing on the first section, i.e., the supply line to the hot water heating station, the maximum line volume is divided into a first maximum volume for the first section and a second maximum volume for the second section. The first pressure in the first section and the first pipe cross section for the first section depend on the length of the first section, so that the line volume of the first section is equal to or less than the first maximum volume. The line volume of the second section must also be equal to or less than the second maximum volume. This requirement must also be met for the distribution line of the second section.

[0024] Preferably, the first pressure is different from the second pressure in the second section. To cover long distances in the supply line, hot water flows through it at high pressure. This pressure is reduced in the hot water supply station. In one embodiment, to achieve high pressure in the first section, a pressure booster is installed upstream of the potable water heater. To reduce the pressure, a pressure regulator is provided in the hot water supply station or a pressure regulator is installed upstream of the hot water supply station.

[0025] In one embodiment, one or more additional water discharge stations are connected to the hot water supply station, and the line volume in each line route between the potable water heater and the additional water discharge station or one of the additional water discharge stations is equal to or less than a specified maximum line volume. Therefore, for the line route to each water discharge station, the line volume is equal to or less than the maximum line volume. Usually, the line route from the potable water heater to the farthest water discharge station has the largest line volume, and therefore, as a rule of thumb, when determining dimensions, it is sufficient if this line volume is equal to or less than the maximum line volume. Further water discharge stations can be provided between the farthest water discharge station and the potable water heater. These water discharge stations are preferably connected to each other by a loop-through installation.

[0026] The following are examples of pressures and pipe inner diameters for specified maximum line lengths. For example, in a hot water supply system, the pipe inner diameter can be 11.6 mm or less. Preferably, the pressure is 0.71 bar or more. This allows for a line length of 25 m to the hot water supply station. For example, the pipe inner diameter can be 9.6 mm or less. Preferably, the pressure is 2.47 bar or more. This allows for a line length of 35 m to the hot water supply station. For example, the pipe inner diameter can be 8.4 mm or less. Preferably, the pressure is 6.01 bar or more. This allows for a line length of 45 m to the hot water supply station. For example, the pipe inner diameter can be 7 mm or less. Preferably, the pressure is 20.81 bar or more. This allows for a line length of 65 m to the hot water supply station. This maximum line length significantly exceeds the line path required in a conventional hot water supply system without a circulation line. In the above embodiment, the pipe has an outer diameter of 16 mm, allowing for uniform pipe outer dimensions to facilitate assembly and installation.

[0027] In one embodiment, the hot water station is equipped with a continuous flow heater, which is designed to heat the hot water from the potable water heater during the discharge time before it reaches the hot water station. This increases comfort in long supply lines, because hot water is immediately available at the discharge point, even if the water in the line is already cold when it is dispensed.

[0028] In one embodiment, the hot water station includes a bypass valve that bridges the instantaneous water heater as soon as hot water having a specified temperature is available at the inlet side of the hot water station. Hot water of a specified minimum temperature bypasses the instantaneous water heater. Nevertheless, the hot water station can include an additional heater that further heats the hot water from the potable water heater.

[0029] In one embodiment, the hot water station includes a compact hot water reservoir having a storage volume smaller than that of the hot water reservoir of the potable water heater. In this embodiment, the hot water station acts as a distributed buffer, providing hot water close to the dispensing station, thereby reducing the time it takes for hot water to become available at the dispensing station.

[0030] Preferably, the compact hot water reservoir has insulation, e.g., made of insulating material, so that heat loss to the environment is reduced and the cooling of the potable hot water is delayed. Additionally or alternatively, the compact hot water reservoir is designed to heat the water stored therein. This allows for reheating of cold water during long downtimes when water is not drawn from the compact hot water reservoir and hot water is not flowing from the potable water heater. Alternatively, the stored water can be heated when it cools below a predetermined threshold that prevents cooling, so that hot water is always available in the compact hot water reservoir for use. Heating for a predetermined time, e.g., in the morning, ensures that hot water is available when needed.

[0031] Additionally or alternatively, the compact hot water container includes a heat exchanger. The heat exchanger includes a phase change material, abbreviated as "PCM." Potable water flows through the primary circuit of the heat exchanger. The secondary circuit includes a phase change material. This phase change material stores most of the thermal energy provided by the primary circuit in the form of latent heat (e.g., during a phase change from solid to liquid). Flowing and / or stored hot water may be heated in the hot water supply station, causing a phase change in the phase change material. As a result, the phase change material stores some of the hot water's thermal energy. Nevertheless, there is sufficient hot water available at the water supply station, especially when the hot water is flowing. The phase change material is, for example, waxy and can liquefy when heat is applied. If there is no water supply for a long period of time, the latent heat stored in the phase change material serves to heat the cooling water and prevent it from cooling. The phase change material solidifies again, releasing the thermal energy released during this process into the stored water. Electric heating can support the supply of hot water by reheating the stored water when it cools below a certain threshold, possibly multiple times, to prevent cooling. As a result, hot water is always available in the small hot water reservoir for use. The energy required for this is significantly lower if no phase change material is provided.

[0032] In one embodiment, the heat exchanger for a compact hot water container has two separate drinking water primary circuits and a secondary circuit containing a phase change material. This design of the hot water station combines the functions of two hot water stations, providing drinking water for two hot water branches, for example, the bathroom and kitchen of an apartment building. The lines of the two branches are isolated from each other. There is no water exchange. However, thermal coupling occurs through the secondary circuits, as heat energy from each primary circuit can be stored in the phase change material and released from the phase change material to each primary circuit. In other words, heat exchange from each of the two separated primary circuits occurs using the secondary circuit, without water exchange between the two primary circuits. Three or more primary circuits can also be provided, and the three or more primary circuits are thermally coupled in this way.

[0033] For example, a long shower with hot water tapped in one hot water branch creates a storage of thermal energy that is then released for tapped water in the kitchen in the other hot water branch. This design provides a further increase in efficiency because when hot water is drawn from one of the primary circuits, the phase change material acting as a storage device is thermally charged and this charged energy storage is also available to the other primary circuit.

[0034] If sufficient hot water is already stored, the water reservoir can be bypassed by a bypass valve, however the regular flow of hot water also preferably results in regular charging of the phase change material acting as a reservoir.

[0035] In one version, the potable water heater is coupled to a heat pump, which heats the cold water to hot water. The line-free system results in high efficiency because the efficiency of the heat pump depends on the temperature gradient between the hot water in the hot water container and the incoming cold water. This is significantly higher than in conventional systems with a line-free circulation. Because there is no line-free circulation, turbulence caused by the returning hot water, and thus the reduction of the temperature gradient, is avoided. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a diagram illustrating a schematic diagram of an exemplary embodiment of a hot water system; [Figure 2] 1 shows a schematic diagram of a further exemplary embodiment of a hot water system; [Figure 3] FIG. 2 is a diagram illustrating a schematic diagram of yet another exemplary embodiment of a hot water system. [Figure 4] FIG. 10 is a diagram illustrating a schematic diagram of yet another exemplary embodiment of a hot water system. [Figure 5] FIG. 1 shows schematic details of an exemplary embodiment of a hot water system. [Figure 6]FIG. 2 shows a schematic diagram of further details of an exemplary embodiment of a hot water system. DETAILED DESCRIPTION OF THE INVENTION

[0037] Some exemplary embodiments are described in more detail below with reference to the figures, in which identical or functionally equivalent components are designated with the same reference numerals.

[0038] 1 shows a schematic representation of an exemplary embodiment of a hot water supply system having a potable water heater 1 with a hot water supply container 3 and, by way of example, two hot water supply stations 51, 52 and three water discharge stations 71, 72, 73. The potable water heater 1 heats cold drinking water flowing into the hot water supply container 3 via a house connection 21 and stores the drinking water in the hot water supply container 3 for hot water supply. Heating is performed, for example, by a heat exchanger 15.

[0039] Between the potable water heater 1 and the water discharge stations 71, 72, 73, a line system 9 without a circulation line is provided, which is designed so that hot water flows from the hot water supply container 3 of the potable water heater 1 to the water discharge stations 71, 72, 73. The hot water is dispensed at the water discharge stations 71, 72, 73. The water discharge stations 71, 72, 73 can be, for example, showers or taps. The hot water supply stations 51, 52 are hot water transfer points and are connected to the potable water heater 1 via supply lines 11. Distribution lines 13 lead from the hot water supply stations 51, 52 to the water discharge points 71, 72, 73, 74. Several connections are provided at the hot water supply stations 51, 52 for the distribution lines 13 to the water discharge stations 71, 72, 73. Several water discharge stations are preferably installed in series, with the distribution line to the most distant water discharge station being looped through the further water discharge stations.

[0040] Between the potable water heater 1 and the first water discharge station 71, hot water flows along a line path via the first water supply station 51. The line path has a first portion between the potable water heater 1 and the first water supply station 51 and a second portion between the first water supply station 51 and the first water discharge station 71. The line volume in the pipe of the line path is less than or equal to a pre-specified maximum line volume of 3 liters.

[0041] Between the potable water heater 1 and the second and third water discharge stations 72, 73, hot water flows via the second water supply station 52. The line path between the potable water heater 1 and the second water supply station 52 has a first portion between the potable water heater 1 and the second water supply station 52 and a second portion between the second water supply station 52 and the second water discharge station 72. The line volume of the line path is less than the specified maximum line volume of 3 liters. The line path between the potable water heater 1 and the third water discharge station 73 extends through the second water supply station 52 and the second water discharge station 72. At the second water discharge station 72, the pipe forms a loop. The line path has a first portion between the potable water heater 1 and the second water supply station 52 and a second portion between the second water supply station 52 and the third water discharge station 73. The line volume in the pipe of the line path is less than the specified maximum line volume. This line path leads to the farthest discharge station 73 and then over the previous line path to the second discharge station 72. This has the largest line volume of all three line paths. The line volume of each line path is less than the specified maximum line volume of 3 liters.

[0042] The hot water supply system is a small system in which the line volume of each line path is less than 3 liters, and the volume of the vessel 3 is 400 liters or less.

[0043] Such a hot water system with two hot water stations 51, 52 may be provided, for example, for two small apartments, with a hot water station 51, 52 located in each apartment. In a two-person apartment, one hot water station is sufficient for the kitchen and bathroom outlets. Alternatively, the hot water system may be designed for a larger apartment for three or four people, with one hot water station 51, 52 for each bathroom and kitchen and their outlets. In a hot water system for multiple residential units, for example, in a multi-unit residential building or apartment complex, three or more hot water stations 51, 52 may be provided. Nevertheless, the hot water system is still a small system.

[0044] The hot water system can be designed for very long line paths. Depending on the desired length of the longest line path, the pressure in the line system and the pipe cross-section, i.e., the inner pipe diameter, of the line system are selected so that the line volume of each line path is below the specified maximum line volume. The longer the desired line path length, the higher the pressure and the smaller the pipe cross-section. The line volume of each line path is less than the maximum line volume of 3 liters. The first section up to the hot water station is preferably optimized by allocating a portion of the maximum line volume to the first section. The remaining maximum line volume is available for the second section. For example, 0.6 liters can be provided for the line volume of the second section of the line path after the heating station, and 2.4 liters can be provided for the line volume between the potable water heater 1 and the first and second hot water stations 51, 52, respectively. In another embodiment, 0.5 liters are provided for the second section and 2.5 liters are provided for the first section.

[0045] The hot water system does not include a circulation line or a fresh water station, which results in high economic efficiency for investment and operation. The line path can be very long, for example, to supply water to a large building or the drinking water heater 1 can be operated outdoors.

[0046] FIG. 2 shows a schematic representation of another embodiment of a hot water supply system comprising a potable water heater 1 having a hot water container 3, a hot water supply station 50 and a water dispensing station 70.

[0047] A residential connection 21 is provided inside the house, and potable cold water is supplied to the potable water heater 1 at the residential connection 21. The residential connection 21 is equipped with a shut-off valve, a water meter, a through valve with backflow prevention function, and a filter. Potable cold water is supplied from the residential connection 21 to the potable water heater 1 via a pressure booster 23 at approximately 4 bar.

[0048] The potable water heater 1 comprises a hot water supply vessel 3 into which cold potable water flows, is heated by a heat exchanger 15, and is designed to supply the heated cold water as hot potable water to the hot water supply vessel 3. The potable water heater 1 increases the pressure, for example at 9 bar, and supplies hot water to a drinking water outlet. Typically, the temperature of the hot water in the hot water supply vessel 3 is a temperature at which bacteria in the water can no longer grow, for example 50°C. The potable water heater 1 is coupled to a heat pump 49, which is designed to heat the water in the potable water heater 1.

[0049] Hot water can flow to the hot water supply station 50 via a line system 9 without a circulation line path and by means of a supply line path 11 connected to the hot water supply station 50. Hot water that remains in the line system 9 for a long time without being drawn off is cooled. The hot water supply station 50 comprises a pressure regulator 31 specially designed for pressure reduction and an electric instantaneous water heater 33. One or more water discharge stations 70 can be connected to the hot water supply station 50 via a water distribution line 13. In this embodiment, the hot water supply station 50 is provided with a water discharge point 70 connected via the water distribution line 13.

[0050] The instantaneous water heater 33 in the hot water heating station 50 is designed to heat the chilled water leaving the line system during the discharge period until hot water flows from the potable water heater 1 to the hot water heating station 50. The thermal bypass valve 17 bridges with the instantaneous water heater 33 as soon as hot water is available at the instantaneous water heater 33.

[0051] Since the line system 9 does not have a circulation line path, hot water from the hot water container 3 is only available at the discharge station 70 after a discharge period when cold water has flowed out of the line system 9. Meanwhile, hot water is supplied by the instantaneous hot water heater 33. The instantaneous hot water heater 33 heats the water leaving the supply line 11 until the line carries hot water. The instantaneous hot water heater is then switched off and bypassed by the bypass valve 17. The fully electric instantaneous hot water heater 33 with the thermal bypass valve 17 allows continuous bypass of the instantaneous hot water heater from a water temperature of 45°C.

[0052] In an exemplary embodiment where the supply line 11 to the potable water heater 1 is short and therefore the discharge time is short, the water heating station 50 can be stopped, for example, by an app.

[0053] In case of emergency, i.e. when the hot water reservoir is only providing cold water and the auxiliary heating is not operating, the instant hot water heater 33 allows for a hot shower or the drawing of hot water at a slightly reduced flow rate.

[0054] The hot water station 50 forms the hot water transfer point from the supply line 11 to the individual piping of the discharge station 70. Internal stainless steel piping with 1 / 4 inch IG connections is provided for field installation of the transfer point. In one embodiment, the piping is available as a raw or completed set, or may be already installed in the hot water station 50 upon delivery.

[0055] In one exemplary embodiment, such a water heating station is a device with a rectangular basic shape and can have exemplary dimensions of 540 x 300 x 82 mm. It weighs approximately 9 kg, making it easy to mount on a wall. It is equipped with a 1 / 2" IG connection. The typical discharge rate is 10 liters / minute, and a connection power of 9 kW is supplied to the instantaneous water heater. The maximum current consumption is 3 x 13 A, with the electrical connection being 400 / 16 / 3 ~ V / A.

[0056] In one embodiment, the operating temperature of the hot water supply station 50 is 50°C or 55°C, which results in reduced limescale deposits. The operating pressure of the hot water supply station 50 is permanently 6 bar, allowing for pressure surges of up to 10 bar. The hot water supply station 50 is also preferably designed to electrically reheat the supplied water, so that hot water from the potable water heater 1, which is at 50°C, is reheated to 60°C in the hot water supply station, which improves comfort.

[0057] All water-bearing components of the hot water system are made of drinking water quality, e.g. copper according to DIN 50930-6, brass according to ENCW 617N or stainless steel AISI 304.

[0058] The hot water system is sized to be a compact system in accordance with DVGW Worksheet W551, which means that the hot water system can be operated at economical temperatures without requiring inspection.

[0059] The maximum line length between the hot water heater and the transfer point is 65 m, with a maximum line volume of 2.4 liters in the first part of the flow path. This leaves a maximum line volume of 0.6 liters for the second part of the line path from the hot water heater station as the transfer point to the discharge station, so as not to exceed the maximum line volume of 3 liters. By optimizing the pressure and pipe diameter in the second part, an additional line length of approximately 9 m can be achieved.

[0060] The following lists pipe and pressure combinations for various line path lengths between the potable water heater and the hot water transfer point. Again, this does not exceed a maximum line volume of 3 liters. A maximum line volume of 2.4 liters is provided for the flow path through the supply line between the potable water heater and the hot water transfer point. The pipes for the line system can be manufactured, for example, from heat-resistant polyethylene, or PE-RT for short.

[0061] With 7x4.5mm pipe (i.e. 7mm inner diameter, 4.5mm wall thickness) with an outer diameter of 16mm, a maximum line length of 65m can be achieved. The pressure is 20.81 bar, and as a result, a flow rate of 10 litres / min of unmixed hot water can be achieved. The system requires a pressure regulator 31 to establish the pressure in the supply line 11, and also a pressure booster 23, as shown in Figure 2. For other dimensions, these components are optional.

[0062] With 8.4 x 3.8 mm pipe with an outer diameter of 16 mm, a maximum line length of 45 m can be achieved. The pressure is 6.01 bar, so that a flow rate of 10 litres / min of unmixed hot water can be achieved. A pressure booster 23 is required for the system.

[0063] A maximum line length of 35 m can be achieved with 9.6 x 3.2 mm pipe with an outer diameter of 16 mm. The pressure is 2.47 bar, resulting in a flow rate of 10 litres / min of unmixed hot water. For this system, a pressure booster 23 is required at pressures below 6 bar.

[0064] A maximum line length of 25 m can be achieved with an 11.6 x 2.2 mm pipe with an outer diameter of 16 mm. The pressure is 0.71 bar, resulting in a flow rate of 10 litres / min of unmixed hot water.

[0065] 3 shows a schematic diagram of another exemplary embodiment of a hot water supply system. The hot water supply system comprises a potable water heater 1 having a hot water supply container 3, a hot water supply station 50, and two water dispensing stations 71, 72. The potable water heater 1 heats cold drinking water flowing into the hot water supply container 3 via a house connection 21 and stores it in the hot water supply container 3 for hot water supply. Heating is performed, for example, by a heat exchanger 15. For example, the temperature of the hot water in the hot water supply container 3 is 52°C. The temperature in the line path can be in the range of 20-51°C due to cooling if water is not drawn for a long time.

[0066] Between the potable water heater 1 and the water discharge stations 71, 72, a line system 9 without a circulation line is provided, through which hot water flows from the hot water container 3 to the water discharge stations 71, 72. The hot water supply station 50 is a hot water transfer point and is connected to the potable water heater 1 via a supply line 11. A water distribution line 13 leads from the hot water supply station 50 to the water discharge points 71, 72. The water discharge points 71, 72 are installed in series, so that the water distribution line 13 loops through the first water discharge station 71 to the farthest second water discharge station 72. The depicted cold water line path 19 is connected in a similar manner.

[0067] The requirements and exemplary dimensions already mentioned in the previous exemplary embodiment apply to the sizing of the supply line 11 and the distribution line 13. The line volume within the pipe of the line path is equal to or less than the specified maximum volume of 3 liters. The volume of the supply line 11 is a maximum of 2.5 liters. The volume of the supply line 13 to the furthest discharge point 72 is a maximum of 0.5 liters.

[0068] During the water discharge time, hot water can be drawn from the compact hot water container 60 until hot water flows from the potable water heater 1 to the hot water station 50. In this exemplary embodiment, a bypass valve is provided which bridges with the hot water container as soon as hot water from the potable water heater 1 is available at the hot water station 50. Alternatively, water can be passed through the hot water station 50 regardless of its temperature to allow for periodic water changes.

[0069] The hot water station 50 includes a small hot water container 60 for storing water. The storage volume of the small hot water container 60 is less than the storage volume of the hot water container 3 of the potable water heater 1. A typical value is 5 liters. The storage volume of the small hot water container 60 is not counted as part of the line volume and should be less than the maximum volume. However, the total volume of all water containers in the system must be less than the maximum storage volume to be exempt from inspection requirements. According to drinking water regulations, the maximum storage volume is less than 400 liters.

[0070] The compact hot water vessel 60 includes insulation 62, which significantly slows the cooling of the stored hot water. The compact hot water vessel 60 is also designed to electrically heat water, so that hot drinking water is available in the compact hot water vessel 60 even if the water has not been drawn for an extended period of time. In an exemplary embodiment, heating to 60°C occurs after a longer dwell time. For example, heating can occur as soon as the temperature of the stored water falls below a pre-specified threshold until the temperature within the compact hot water vessel 60 exceeds a further pre-specified threshold. For heating, a heating element 66 is provided, which can have an exemplary power of 100 watts.

[0071] The compact hot water vessel 60 includes a heat exchanger 64, e.g., a plate heat exchanger. The heat exchanger 64 has a primary circuit for drinking water and a secondary circuit with a phase change material, or PCM for short. Alternative exemplary embodiments of the heat exchanger include finned tubes or an aluminum body with a large surface area. The phase change material stores most of the thermal energy supplied to it from the primary circuit in the form of latent heat (especially during the phase change from solid to liquid). The phase change can occur at approximately 45°C when the wax-like phase change material melts. The phase change occurs below the desired temperature of the hot water. The flow and heating of the hot water causes the phase change of the phase change material, which stores some of the hot water's thermal energy. Nevertheless, even after the hot water has passed through, the thermal energy partially used for the phase change is sufficient to provide hot water at the dispensing station. If there is no water dispensed for an extended period of time, the thermal energy stored in the phase change material serves to slow the cooling of the stored water. The phase change material solidifies and releases the thermal energy released during this process into the stored water, heating it.

[0072] For example, hot water from a supply line at approximately 50°C may cause a phase transition in the phase change material, which liquefies in this temperature range. Nevertheless, water at approximately 40°C may be drawn from the water dispensing stations 71, 72.

[0073] The combination of the heat exchanger 64 with a phase change material, the heating element 66, and the insulation 62 significantly reduces the energy required to provide hot water near the discharge stations 71 and 72. Compared to an instantaneous water heater, the energy requirements for the water heating station 50 are reduced by approximately seven times. The insulation 62 can maintain the water temperature for at least 24 hours, so that the hot water can be dispensed without reheating. The water heating station 50 can provide hot water at the discharge stations 71 and 72 in just 8 to 15 seconds. In addition, the lower pressure loss of the plate heat exchanger allows for a discharge capacity of 15 liters per minute. This means that the discharge capacity and hot water supply time are superior to the previous embodiment with an instantaneous water heater.

[0074] The hot water station 50 with the compact hot water container 60 has approximately the same dimensions as the hot water station 50 with the instant hot water heater 33. However, the depth is usually greater due to the insulation 62. The connections and fittings are the same.

[0075] In this exemplary embodiment of the system, the water discharge stations 71, 72 each have a small thermal storage device 80. In the small thermal storage device 80, hot water can be stored immediately before it leaves the water discharge stations 71, 72. The small thermal storage device 80 is a compact and small thermal storage device, designed, for example, as an undercounter thermal storage device. The small thermal storage device 80 can often store about 0.5 liters of water. The optional small thermal storage device 80 increases the convenience of the hot water supply time, which is reduced to less than 8 seconds. A typical value is 5 seconds.

[0076] The compact heat storage tank 80 includes insulation to slow the cooling of the water. Preferably, the compact heat storage tank 80 also includes a heat exchanger and heating element with a phase change material, the operation of which has been previously described. Power consumption is approximately 50 watts.

[0077] The storage volume of the small thermal accumulator 80 is also not included in the line volume and must be less than the maximum volume to be considered a small system. However, the storage volume of the small thermal accumulator 80 is significant towards the total volume of all water containers in the system and must be less than the maximum storage volume to be exempt from the obligation to check.

[0078] The storage volume of the compact hot water vessel and compact heat store is not part of the line volume, so the maximum line volume is not exceeded in this exemplary embodiment.

[0079] The highly efficient in-line small hot water reservoir 60 in the hot water supply station 50, especially in combination with the optional small heat storage reservoir 80, reduces the expected time before hot water is available at the water supply station significantly shorter than in conventional systems.

[0080] A water heating station with a small hot water container and a small thermal storage device consumes significantly less electrical energy than a water heating station, especially when compared with a water heating station with an instantaneous hot water heater. The power consumption of a water heating station 50 with an optional small thermal storage device and a small hot water container 60 is almost negligible compared to the power consumption of a water heating station 50 with an instantaneous hot water heater 33. This advantage is particularly important in large systems with many water heating stations 50 and therefore many residential units. Due to the low energy consumption, with an exemplary power consumption of 50 to 100 watts, the total mains connection power is significantly less than that of conventional systems, but also significantly less than the aforementioned exemplary embodiment. With multiple water heating stations 50, a simultaneous lock to limit the number of water heating stations 50 operating simultaneously is no longer required. Smaller cable cross-sections can be used for the power supply. No additional transformer stations are required. This overall lower cost for the power supply also translates into lower planning expenditures for the system, especially for the power supply.

[0081] 4 shows a schematic diagram of another exemplary embodiment of a hot water system. The following description focuses on the differences from the previous exemplary embodiment from FIG.

[0082] In this exemplary embodiment, two hot water branches 10, 20 are provided. On the one hand, hot water from the potable water heater 1 is led to first and second outlet stations 71, 72 in the first hot water branch 10, and on the other hand, hot water from the potable water heater 1 is led to third and fourth outlet stations 73, 74 in the second water branch 20. Although the hot water branches 10, 20 are separate, no water exchange occurs; both hot water branches 10, 20 are provided through the same hot water station 50. The hot water branches 10, 20 have separate supply lines 11 and separate distribution lines 13. The hot water branches 10, 20 are assembled using loop-through installations and small heat accumulators 80, as in the previous exemplary embodiment.

[0083] Similar to the previous exemplary embodiment, the water heating station 50 comprises a compact water heating container 60, insulation 62, a heat exchanger 64, and a heating element 66. Since the water heating station 50 is provided for two water heating branches 10, 20, the water heating station 50 has two connections for the water distribution line 13. The housing dimensions are larger than in the previous exemplary embodiment in order to store more water for the two branches 10, 20.

[0084] In each of the branches 10, 20, the line volume within the pipe of the line path is less than or equal to a pre-specified maximum line volume of 3 liters.

[0085] The two water branches 10, 20 run through the same hot water station 50 as the two primary circuits of the heat exchanger 64. Figure 5 shows a schematic representation of the hot water station 50 with an influent 111 and an effluent 131 in the first branch 10 and an influent 112 and an effluent 132 in the second branch 20. There is no mixing of drinking water between the branches 10, 20. Nor does mixing occur in the hot water station 50. In addition to the separate distribution lines 13, the hot water branches 10, 20 also have separate supply lines 11 running between the drinking water heater 1 and the hot water station 50.

[0086] The secondary circuit of heat exchanger 64 contains a phase change material and interacts with both primary circuits. As a result, thermal coupling occurs through the secondary circuits, such that heat from each of the primary circuits can be stored in and released from the secondary circuit to each of the primary circuits. In this manner, the phase change material is charged by one primary circuit, and the stored thermal energy is then transferred to the other primary circuit.

[0087] FIG. 6 shows a detailed schematic diagram of an exemplary embodiment of the heat exchanger 64 for the previous exemplary embodiment from FIG. 5 . The heat exchanger 64 is designed as a plate heat exchanger. The plates are alternately provided with a phase change material 68 and water in the first and second branches 10, 20. However, the water in the first branch 10 in the primary circuit flows through plates that are spatially separated from the water in the second branch 20 in the secondary circuit, preferably alternately. As a result, the water in the first branch 10 flows through the phase change material 68 between two adjacent plates on one side, while the water in the second branch 20 flows through said material on the other side. As a result, even if the accumulation of thermal energy is caused only by water discharge in one of the branches 10, 20, the thermal energy stored in the phase change material 68 can be transferred to both the first and second primary circuits. Nevertheless, both primary circuits can charge the phase change material 68.

[0088] For example, in a shower in the first branch 10, more hot water is typically drawn for a longer period of time, causing a buildup of thermal energy in the secondary circuit. This built-up thermal energy can then be released for water extraction in the kitchen in the second branch 20 and for hand washing, for example, in the bathroom, which is connected to the first branch 10.

[0089] Another feature and use of the hot water station, namely, insulation and heating of the stored water, discussed above in connection with Figure 3, is also implemented in the hot water station of Figures 4-6 to heat the water in the hot water station for both branches 10, 20 and slow its cooling. In this manner, the insulation 61 can maintain water hot enough to dispense hot water for up to 24 hours. In this exemplary embodiment, a 100-watt heating element 66 is also provided, which allows the cooled water in the compact hot water reservoir 60 to be heated to 60°C after a longer dwell time.

[0090] The exemplary embodiment described in connection with FIGS. 4-6 has the same advantages as the exemplary embodiment described in connection with FIG. 3. In both hot water supply branches 10, 20, the output volume is less than a predetermined value, in particular, less than 3 liters. The discharge volume exceeds 20 liters / minute for the water outlet stations 71, 72, 73, 74 supplied by the two hot water supply branches 10, 20. The drinking water supply is more powerful, even though it requires less energy. Planning and implementation are also simplified, since when two heat stations 50 are provided for the two hot water supply branches, only one installation route is provided instead of two. Even if the heat stations 50 have the same or similar power consumption of 100 W as in the previous exemplary embodiment, the provision of stored thermal energy for both primary circuits leads to increased efficiency.

[0091] The components of the hot water system described above in relation to the drawings are supplied by the manufacturer and then installed on site, particularly in combination with a heat pump that is also used to heat drinking water. In such an embodiment, the components are optimized for operation with the heat pump. The potable water heater 1 has very good efficiency because there is no turbulence or mixing caused by hot water flowing back into the heat accumulator 3, as is the case with a circulation line. The circulation line-free system 9 leads to high efficiency of the hot water system, since the efficiency of the heat pump depends on the temperature gradient.

[0092] The features described above and in the claims, as well as those seen in the drawings, can preferably be implemented individually and in various combinations. The invention is not limited to the exemplary embodiments described, but can be varied in many ways within the capabilities of those skilled in the art. [Explanation of symbols]

[0093] 1. Potable water heater 3 Hot water container 9-line system 11 Supply Line 13 Water Distribution Line 15 Heat exchanger 17 Bypass valve 19 Cold water line 21 House Connection 23 Pressure Booster 31 Pressure Regulator 33 Instantaneous water heater 49 Heat Pump 50, 51, 52 Hot water station 60 Small hot water container 62 Insulation 64 Heat exchanger 66 Heating element 68 Phase Change Materials 70, 71, 72, 73, 74 Water Discharge Station 80 Small heat storage device

Claims

1. A drinking water heater (1) having a hot water container (3), Water discharge stations (70, 71, 72, 73, 74); a circulation line-free line system (9) between the drinking water heater (1) and the water discharge stations (70, 71, 72, 73, 74), the circulation line-free line system (9) being designed so that heated drinking water flows from the drinking water heater (1) to the water discharge stations (70, 71, 72, 73, 74) along a line path of the line system (9); Equipped with the pressure in the line system and the pipe cross section of the line system depend on the length of the line path, and therefore the line volume of the line path is less than or equal to a predetermined maximum line volume; the line path includes a first portion and a second portion; A hot water supply system, characterized in that hot water supply stations (50, 51, 52) are provided in the line system (9) between the first part and the second part and are designed to heat and / or store the drinking water.

2. 2. The hot water supply system of claim 1, wherein the first pressure in the first section and the first pipe cross section of the first section depend on the length of the first section, and the sum of the first line volume of the first section and the second line volume of the second section is less than or equal to the predetermined maximum line volume.

3. 3. A hot water supply system as described in claim 1 or 2, wherein one or more further water discharge stations (70, 71, 72, 73, 74) are connected to the hot water supply station (50, 51, 52), and the line volume in each line path between the potable water heater (1) and the one or more water discharge stations (70, 71, 72, 73, 74), or one of the further water discharge stations (70, 71, 72, 73, 74), is less than the predetermined maximum line volume, in particular less than 3 liters.

4. If the length of the first section is at most 25 m, or at most 35 m, or at most 45 m, or at most 65 m, the first pipe cross section has a diameter of at most 11.6 mm, in particular at most 9.6 mm, in particular at most 8.4 mm, in particular at most 7 mm, 3. The hot water heating system of claim 1, wherein the first pressure is at least 0.71 bar, in particular at least 2.47 bar, in particular at least 6.01 bar, in particular at least 20.81 bar, if the length of the first portion is at most 25 m, or at most 35 m, or at most 45 m, or at most 65 m.

5. 3. A hot water system according to claim 1 or 2, wherein a pressure booster (23) is connected upstream of the potable water heater (1).

6. 3. The hot water system according to claim 1 or 2, wherein the hot water stations (50, 51, 52) are equipped with a pressure regulator (31) or have a pressure regulator (31) connected upstream thereof.

7. 3. The hot water system of claim 1 or 2, wherein the hot water station (50, 51, 52) comprises a continuous flow heater (33) configured to heat water.

8. 3. The hot water supply system according to claim 1 or 2, wherein the hot water supply stations (50, 51, 52) comprise small hot water containers.

9. The compact hot water vessel (60) has a thermal insulation material (62), and / or The small hot water vessel (60) is designed to heat water stored therein; and / or 9. The hot water system of claim 8, wherein the compact hot water vessel (60) includes a heat exchanger (64) comprising a phase change material (68).

10. 10. The hot water system of claim 9, wherein the heat exchanger (64) of the compact hot water container (60) has two separate potable water primary circuits (10, 20) and a secondary circuit containing the phase change material (68).

11. The hot water supply station (50, 51, 52) has a bypass valve (17), 3. The hot water system according to claim 1 or 2, wherein the bypass valve switches to an open state as soon as hot water having a predetermined minimum temperature is available at the inlet side of the hot water station (50, 51, 52).

12. The hot water supply system according to claim 8, wherein at least one of the water discharge stations (70, 71, 72, 73, 74) is provided with a small heat accumulator (80) having a water storage volume lower than the water storage volume of the small hot water supply container (60).

13. 3. The hot water system according to claim 1 or 2, wherein the line system (9) does not include a fresh water station.

14. 3. The hot water system according to claim 1 or 2, which is a compact system according to the German Drinking Water Regulation, in particular DVGW Worksheet W551.

15. 3. A hot water system according to claim 1 or 2, wherein the potable water heater (1) is connected to a heat pump (19) designed to heat the water in the potable water heater (1).

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