Method for operating a temperature-controlled circulation system, and temperature-controlled circulation system

Abstract

The present invention relates to a method for operating a circulation system (10) comprising a cooling device (12, 14) with input ports (12a, 14a) and output ports (12b, 14b) for cooling water, said method comprising the following steps: determining temperature start values ​​TMA, T according to a model of the axial temperature variation of a first partial section adjacent to the output ports (12b, 14b); MA * <T soll and the volume flow rate start value V z *, determining and in particular calculating the temperature change of the water between the initial region and the end region, starting from *, and determining and in particular calculating the temperature change of the water between the initial region and the end region of each further subsection according to a temperature change model under the constraint that the water temperature in the initial region of the subsection is equal to the water temperature in the end region of the subsection adjacent to the given subsection, and in the end region of each subsection, the water temperature is equal to TME, T ME <T soll At the input ports (12b, 14b), the water temperature is T b <T soll is set to T soll and selecting a value Ta of the water temperature at the output ports (12b, 14b) and a value Vz of the volumetric flow rate such that -Tb<θ, where θ>0 is a given value. The invention also relates to a circulation system for implementing the method.

Description

Technical Field

[0001] The present invention relates to a method for operating a circulation system and a circulation system, in accordance with the features of the preamble of the independent claim each time.

Background Art

[0002] To prevent microbial growth in the cold water network, according to DIN EN 806 and VDI Guideline 6023, it is necessary to always limit the temperature of the cold drinking water (PWC) in all lines of the facility to a value of +25°C or less for the drinking water facilities in the building. According to DIN EN 806-2, 3.6, for cold water locations, the water temperature should not exceed +25°C within 30 seconds after the tapping point is fully open. Furthermore, to prevent water stagnation, the cold water facility needs to be designed such that drinking water is regularly replenished in all lines of the facility under normal operating conditions. Similarly, VDI Guideline 6023 also includes a recommendation to keep the temperature of the drinking water as low as possible below +25°C. Naturally, the limitation of the water temperature is often considered necessary for other water facilities such as facilities for industrial process water.

[0003] The occurrence of a high PWC temperature is promoted by the single or combined occurrence of various situations as follows. ·Already high PWC temperature at the joints in the household, ·Thermal influence on the area of the facility, for example, due to the location and orientation of the building or the area of the facility within the building, ·Insufficient insulation of the PWC pipeline to block heat, ·Installation of PWC pipelines in rooms and equipment spaces with heat sources in general installation areas such as shafts, ducts, suspended ceilings, installation walls equipped with heat-generating media (pipeline of the heating system, drinking warm water (PWH), drinking warm water circulation system (PWH-C), intake and exhaust ducts, lamps, etc.), ·Stagnation stage in the aforementioned installation area, ·Highly branched PWC installation associated with the volume of large equipment, · An overly large PWC pipeline.

[0004] The preferred method in efforts to meet the rules imposed at the residence stage has so far been the forced cleaning of the equipment to simulate the desired operations at these stages.

[0005] To provide cold and warm drinking water, various cooling circulation systems have already been proposed for the cold water network.

[0006] Cooling circulation systems are already known from Patent Document 1, and a controlled addition of disinfectant to water has been proposed.

[0007] From Patent Document 2, a method of operating a circulation system is known that includes heat storage, a circulation pump, a regulating unit, and at least two branches, and otherwise has an unknown pipe network structure. The branches, each equipped with a valve adjustable by a drive motor, coincide with temperature sensors arranged upstream of each mixing point between the branches. The drive motor and / or the circulation pump are connected to the regulating unit by wireless or wired means for data exchange. The regulating unit is designed to perform thermal and hydraulic balancing, as well as thermal disinfection, by restricting the range of measured temperatures and / or by adjusting the pump output according to the difference between the actual temperature value and the target temperature value.

[0008] From Patent Document 3, an arrangement of drinking water and service water supply for a building with a domestic connection for cold water connected to a public supply network is known. The supply device includes a pump and at least one circulation conduit leading to at least one consumer. A heat exchanger for extracting heat from the water is provided in the circulation conduit.

[0009] Furthermore, Patent Document 4 describes a type of drinking water and raw water supply apparatus known in Patent Document 3, wherein the heat exchanger is formed by latent heat storage and is connected to a control device for control purposes, and includes an electric cleaning valve provided in a circulation conduit. The cleaning valve is disposed between the latent heat storage and the point where the domestic joint enters the circulation conduit and is located in the downstream flow direction from the latent heat storage.

[0010] A known circulation system for cooling water does not guarantee, or effectively guarantee, that the water temperature is below the desired temperature for all sub-sections and at all times during the operation of the circulation system.

[0011] Patent Document 5 of the applicant of the present application already describes a method for operating a circulation system equipped with a cooling device, and this method - starting from a starting temperature value T MA * <T soll and a starting volumetric flow rate value V z * determining, in particular calculating, the temperature change of the water between a starting range and an end range corresponding to a model of the axial temperature change of a first sub-section connected to an outlet port (12b, 14b); - for each additional sub-section given, determining, in particular calculating, the temperature change of the water between a starting range and an end range under the boundary condition that the water temperature within the starting range of the given sub-section is equal to the water temperature within the end range of the sub-section to which the given sub-section is connected, corresponding to the model of the temperature change; - at the end range of each sub-section, the water temperature is T ME <T soll and at the inlet port (12a, 14b), the water temperature is T b <T soll is set to T soll - T b <θ, where θ > 0 is a predetermined value, such that the value T of the water temperature at the outlet port (12b, 14b) a and the value V of the volumetric flow rate zThe step of selecting, and the like.

[0012] The content of Patent Document 5 cited above is fully incorporated by reference in the disclosure of the present application.

[0013] In the case of a hot water network, similar problems exist for the cold water network. Here, the operating temperature varies, but there is an accumulator or a heater instead of a cooling device. The temperature of the hot water network should be between 60 °C at the accumulator outlet and 55 °C at the accumulator inlet. In contrast to the cold water network where the temperature rise is due to heat absorption from the surroundings, heat loss causes a temperature drop in the hot water network.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0015] Therefore, the problem proposed to be solved by the present invention is to effectively ensure that the water temperature is within the desired temperature range for all sub - sections and for all times during the operation of the circulation system.

[0016] Furthermore, one problem that the present invention attempts to solve is to effectively ensure that the water temperature remains above the nominal temperature throughout all subsections and at all times during the operation of the circulation system.

Means for Solving the Problems

[0017] This problem is solved according to the present invention with the features of the independent claims.

[0018] Thus, generally, the present invention also includes cases where the equations used for per-model calculations are adaptively adjusted accordingly, and a temperature control device such as a heat exchanger is used instead of a cooling device that can heat or cool water. Preferably, the temperature control device is configured as a heating device.

[0019] The method according to the present invention relates to a circulation system having a pipeline system with a plurality of branches having one or more subsections (some sections) having an input port and an output port, having a given thermal coupling to the surroundings, and being connected by nodes, wherein one or more lines of the pipeline system are configured as flow pipes, at least one is connected to a tapping point as a single supply line, and at least one line is configured as a circulation conduit connected to one or more flow pipes.

[0020] The method according to the present invention for operating a circulation system is based on the model of the axial temperature change of the first subsection connected to the output port, with the temperature start value T MA *<T soll and the volume flow start value V zStarting from *, the temperature change of the water between the initial region and the end region is determined, and under the boundary condition that the water temperature in the initial region of a given partial section is equal to the water temperature within the end region of the partial section to which the given partial section is connected in the water flow direction, the temperature change of the water between the initial region and the end region is determined for each further partial section connected to the first partial section according to the model of the temperature change, and at the end region of each partial section of the circulation system, the water temperature is T ME <T soll and at the input port, the water temperature is T b <T soll is set to T soll -T b <θ, where the value T of the water temperature at the output port is such that θ > 0 is a given value a and the value V of the volumetric flow rate z are selected.

[0021] Preferably, the determining step consists of calculating the axial temperature change of the water between the initial region and the end region of the partial section, i.e., the corresponding conduit, based on the heat absorption from the surroundings of the partial section according to the model. Thus, starting from the first partial section connected to the temperature control device, moving continuously through the entire system of partial sections, and thus calculating the temperature of the entire system.

[0022] According to the present invention, at the end region of each partial section of the circulation system, the water temperature is T ME <T soll and the water temperature T b <T soll at the input port is T soll -T b <θ, where θ > 0 is a predetermined value, and the value T of the water temperature and the value V of the volumetric flow rate a at the output port are determined in this way by modeling, preferably by calculation, the temperature and volumetric flow rate of the circulating water in the conduit system. This is preferably carried out with V z in a stable state. z being in a stable state.

[0023] Next, the temperature control device, and in some cases the circulation pump of the circulation system is adjusted, as a result of which the water temperature and the volumetric flow rate are the confirmed values T a and the value V z are taken.

[0024] According to the present invention, it is proposed that the temperature is set at the output port, the temperature change is calculated based thereon, and it is used for modeling according to the characteristic context of claim 1.

[0025] The advantage of the calculation is that no sensor is required to measure anything, the influencing factors can be evaluated and diversified, and in some cases prediction is also possible.

[0026] The calculation provides the advantages that fewer measurement points are required compared to a two-point adjustment system and / or cascade control of the building floor, or control by pipeline branching, and the overall system is less likely to fluctuate.

[0027] Therefore, in contrast to the prior art, the adjustment according to the present invention is achieved by setpoint operation at the output port, but the design of the regulator is based on the overall waterway system with distributed parameters and the calculation of a plurality of temperature TMEs. Therefore, basically only one regulator and one temperature setting are required to provide the temperature Ta.

[0028] The following equation applies to both the temperature drop of the hot water network and the temperature rise of the cold water network.

[0029] TIFF0007682543000001.tif16170 q = specific heat flux in W / m units Δθ = θmedium start - θmedium end for hot water Δθ = θmedium end - θmedium start for cold water

[0030] Therefore, the present invention also encompasses a similar example of a hot water network where a storage tank or a heater is used instead of the temperature control device.

[0031] Furthermore, the given equation also applies to the cold water network when the temperature of the water is higher than the ambient temperature.

[0032] Thus, in general, the present invention includes, as already described, the case of using a heat exchanger instead of a temperature control device that can heat or cool water, along with the corresponding adaptation of the equations used in the model calculations.

[0033] The term "branch" is composed of one or more sub - sections between two nodes and means that there are no nodes between the nodes. The branch is connected across the nodes.

[0034] Preferably, the boundary condition that the water temperature in the initial region of a given sub - section is equal to the water temperature in the end region of the sub - section to which the given sub - section is connected is only relevant to the sub - sections of each branch.

[0035] The temperature and magnitude of the volumetric flow rate appearing in an adjacent sub - section from a certain node depend on the temperature and magnitude of the inflowing volumetric flow rate. The present invention preferably assumes that these are given by the design of the pipeline system.

[0036] The distribution of the volumetric flow rate exiting from a node between different outflow lines or sub - sections is preferably assumed by the present invention to be given by the design of the pipeline system.

[0037] Preferably, the mixing temperature when the branches are integrally joined and the temperature when the branches are split are calculated based on the percentage of the volumetric flow rate distribution.

[0038] In the method according to the invention, the pipeline system is assumed as given, and it should be understood that the pipeline system is designed in accordance with the rules of DIN 1988-300 for the design of the pipe network, which specify the nominal width of a particular PWC (Potable Water Cold) line and the value of the thermal coupling to the surroundings of the circulating water. It should also be understood that the design of the pipe network specified or recommended in other countries or regions can generally be taken into account.

[0039] Preferably, the maximum allowable value according to the design of the pipeline system is selected as the starting value of the volumetric flow rate Vz*. This value decreases until the temperature of the circulating water approaches T soll This is because as the volumetric flow rate decreases, the temperature of the circulating water rises, and thus the temperature at the input port rises. is due to the fact that as the volumetric flow rate decreases, the temperature of the circulating water rises, and thus the temperature at the input port rises.

[0040] Preferably, the water temperature at the input port is T b < T soll and T soll― T b < θ, where θ > 0 is a predetermined value, the value T MA * changes, and the maximum value of the water temperature T a is selected.

[0041] T soll― T b < θ is given, it is guaranteed that the water temperature of the circulation system does not become too cold and the system does not operate in an energy-inefficient way. Usually, θ is in the range of 1 °C to 5 °C, but it can also be in another range.

[0042] The determination of the water temperature change between the initial region and the end region of each partial section can be carried out according to a model known per se, for example by simulation calculations or appropriate known equations.

[0043] When implementing the method of the present invention, the circulation system preferably operates in a state where water removal and water intake do not occur. This is because in this state, it can be expected that water heating will be greater than in the state where water removal occurs. Therefore, the parameter T a and V z determined by this method are used to ensure a safety margin from an undesirably high water temperature state.

[0044] The parameter T a and V z determined by this method are advantageously used to model a given circulation system in which the pipeline system is designed according to the legal specifications regarding the nominal width and the thermal coupling to the surroundings of the circulating water, and to operate so that the mandatory rules regarding the temperature of the drinking water in the circulation system are satisfied.

[0045] It has been revealed by the applicant's simulation of the existing system that by using the parameters set according to the present invention, a) the above-mentioned legal requirements are satisfied, and b) greater energy efficiency of the system operation is achieved.

[0046] The parameter T a and V z determined by this method are advantageously used to determine the design of the temperature control device regarding its cooling capacity in a given circulation system in which the pipeline system is designed according to the legal specifications regarding the nominal width and the width and thermal coupling to the surroundings of the circulating water. Furthermore, the design of the circulation pump can be determined regarding its pump output.

[0047] In this document, the following terms are used in a specific meaning, and this definition depends on the standard DIN EN806.

[0048] The circulation conduit of the circulation system indicates the conduit downstream of the tapping point of the circulation. If no further tapping point is connected to this conduit, the water returns from the output port of the temperature control device to the input port of the temperature control device.

[0049] The term node is used for the duct element to which the ducts are connected. At least two volume flows can enter the node, and exactly one volume flow can exit the node, or exactly one volume flow can enter the node and at least two volume flows can exit the node. The node corresponds to a branch point.

[0050] Preferably, exactly two volume flows enter the node of the circulation system and one volume flow exits therefrom, or exactly one volume flow enters and exactly two volume flows exit therefrom, for example, in the form of a T-piece.

[0051] Kirchhoff's first law is applied to the nodes of the circulation system, as in an electrical circuit, so that the sum of the inflowing volume flows is equal to the sum of the outflowing volume flows.

[0052] Preferably, the outflow volume flow at each node point is distributed to outflow volume flows of the same size. It should be understood that other distributions are possible.

[0053] In the case of a node having exactly one outflow volume flow and exactly one inflow volume flow at different temperatures, the temperature t m and mass flow rate m m of the mixed water of the outflow volume flow are preferably assumed to be related to the temperature tk and mass flow rate mk of the cold flow, or the temperature tw and mass flow rate mw of the warm flow, by the following equation.

[0054] TIFF0007682543000002.tif11170 t m = Temperature of the mixed water (°C) t k = Temperature of the cold water (°C) t w = Temperature of the warm water (°C) m m = Mass / volume (flow rate) of the mixed water (kg; m 3 ; kg / h; m 3 / h or %) m k = mass / volume (flow rate) of cold water (kg; m 3 ; kg / h; m 3 / h or %) m w = mass / volume (flow rate) of warm water (kg; m 3 ; kg / h; m 3 / h or %)

[0055] To determine the temperature change of water between the initial and end regions of a sub-section, preferably the following parameters can be used together with the length of the sub-section. T Luft = temperature of the ambient air (°C) k R = heat transfer coefficient of the pipeline (W / (m*K)) m M = mass flow rate of water in the sub-section (kg / s) c p , m = specific heat capacity of water (J / (kg*K) V M = volume flow rate of water in the sub-section (m 3 / s) p M = density of water (kg / m 3 )

[0056] Advantageously, the temperature change of water between the initial and end regions can be determined for each sub-section of the circulation system during a steady volume flow rate, and the water temperature at the end region of a given sub-section is selected to be equal to the water temperature in the initial region of the sub-section to which the given sub-section is connected in the direction of the circulating water flow. Thus, for each sub-section of the circulation system, it is possible to determine the water temperature at the end region of each sub-section by starting from the temperature of the initial region.

[0057] Advantageously, starting from the temperature at the output port during a steady volume flow rate, it is possible to determine the temperature of the circulating water for each sub-section, i.e., the water temperature for the end regions of all sub-sections is T ME < T sollso that the initial temperature of the sub-section adjacent to the output port is the value T of the water temperature at the output port a can also be determined.

[0058] In a further embodiment of the present invention, the value T a and V z are proposed to be determined by an iterative approximation procedure, and the water temperature T ME in the end region is the temperature start value T MA * of the first sub-section connected to the output port soll and the volume flow start value V z *, starting from which it is calculated for each given sub-section and then the water temperature T MA ’ in the initial region of the next connected sub-section is selected to be equal to the water temperature T ME in the end region of the given sub-section.

[0059] In a further embodiment of the present invention, it is proposed that the sub-sections are designed axially uniformly with respect to their thermal coupling to the surroundings along the length between their initial and their end regions, i.e., they do not vary axially. This enables the simplification of the calculation.

[0060] In a further embodiment of the present invention, it is proposed that the water temperature T ME in the end region of at least one sub-section having a length L is determined by an equation.

[0061] TIFF0007682543000003.tif22170 L = length (m) of the uniform sub-section (T S1 ) T MA = water temperature in the initial region (°C) T ME = water temperature in the end region (°C) T Luft = temperature of the ambient air (°C) k R = heat transfer coefficient of the pipeline (W / (m*K)) m M= Mass flow rate of water in the partial section (kg / s) c p , m = Specific heat capacity of water (J / (kg*K) V M = Volume flow rate of water in the partial section (m 3 / s) p M = Density of water (kg / m 3 )

[0062] With this equation, an appropriate estimate of the temperature change in the uniform partial section is possible. In another embodiment of the present invention, it is proposed that the heat transfer coefficient of the partial section be determined by an equation.

[0063] TIFF0007682543000004.tif11159 1 / k R = Thermal resistance of the pipeline (m*K / W) α i = Internal heat transfer coefficient (W / (m 2 *K)) 1 / ΔR = Thermal resistance (m*K / W) α a = External heat transfer coefficient (W / (m 2 *K)) d a = Outer diameter (m) d i = Inner diameter (m) TIFF0007682543000005.tif9154

[0064] In the following, it is assumed that equations 1 to 4 are used to determine the temperature change and heat increase in water due to the temperature difference with the surroundings.

[0065] For this reason, equation 1 for thermal resistance is inserted into equation 2, thereby obtaining the heat transfer resistance. The heat transfer coefficient, equation 3, is calculated using the reciprocal of equation 2.

[0066] Thermal resistance 1 / λ of a pipeline including heat insulation ges Refer to Equation 1, VDI 2055, 2008 TIFF0007682543000006.tif13170

[0067] Thermal transition resistance 1 / U of an insulated pipeline R Refer to Equation 2, VDI 2055, 2008 TIFF0007682543000007.tif33170

[0068] Heat transfer coefficient U of a heat-insulated pipeline R Equation 3 TIFF0007682543000008.tif17170

[0069] The heat transfer coefficient is a central element of Equation 4 for calculating the temperature at the end of a subsection.

[0070] Using Equation 4, the respective starting and ending temperatures of the cold water are determined for all relevant subsections. The derivation of the formula for axial heating of the water in the pipeline starts from Equation 5.

[0071] Equation 4 TIFF0007682543000009.tif13170

[0072] Refer to Equation 5, VDI 2055, 2008 TIFF0007682543000010.tif93170 Δθa = θ MA -θ Luft Insert and then integrate. TIFF0007682543000011.tif14170

[0073] In an iterative calculation that gradually / steps up the volume flow rate, for example, determine the volume flow rate for operating a cold water facility with a desired / given spread of 5 K (15 °C / 20 °C).

[0074] With the help of this solution, it is possible to determine not only the volume flow rate of the circulation system, which is a major consideration, but also the water temperature at any given point within a specific pipeline network.

[0075] Preferably, the iterative approximation method is a known Excel goal seek; see Franz Josef Mehr, Maria Teresa Mehr, Wiesbaden, Excel and VBA: Introduction to Practical Applications in the Natural Sciences, 2015, Section 8.1.

[0076] According to the present invention, for example, as follows, important data of a pipeline system including the parameters shown above for a sub-section is input into a program, and using goal seek, the volume flow rate V b at which the drinking water target temperature T z is achieved is determined.

[0077] TIFF0007682543000012.tif207170 TIFF0007682543000013.tif121170

[0078] In this example, the calculated volume flow rate V a at which the target temperature Tb of 20 ° is achieved for an input temperature T of 15 °C is shown in MT4. z

[0079] In a further embodiment of the present invention, it is proposed that a circulation pump is integrated into the circulation system, as a result of which a desired volume flow rate can be set.

[0080] Of course, some temperature control devices and / or circulation pumps may also be provided.

[0081] ​In the following, the embodiments will be described using a pipeline structure as commonly used in drinking water facilities in buildings.

[0082] The connection line is a line between the supply line and the drinking water facility or the circulation system.

[0083] The consumer line is a line that taps from the main shut-off valve to the joint of the tapping point (the faucet part) and, optionally, conveys water to the appliance. The collective supply line is a horizontal consumer line between the main shut-off valve and the riser pipe. The riser pipe (down pipe) leads from one floor to another floor, from which the floor line of the building or a single supply line branches off. The floor line of the building is a line that branches off from the riser pipe (down pipe) within the floor of the building, from which a single supply line branches off. The single supply line is a line that leads to the tapping point.

[0084] In one embodiment of the present invention, it is proposed that at least one flow pipe is connected to at least one loop line.

[0085] In a further embodiment of the present invention, it is proposed that at least one branch of the circulation conduit exits from at least one flow pipe.

[0086] In a further embodiment of the present invention, it is proposed that at least one branch of at least one circulation conduit exits from at least one loop line.

[0087] In a further embodiment of the present invention, it is proposed that at least one flow pipe includes at least one riser line and / or the floor line of the building.

[0088] In a further embodiment of the present invention, it is proposed that at least one flow pipe includes a collective supply line connected to the water supply network by a joint.

[0089] In a further embodiment of the invention, it is proposed that the junction is connected to at least one connection line and / or at least one consumer line.

[0090] In a further embodiment of the invention, it is proposed that at least one static or dynamic diverter is arranged in at least one flow pipe and / or at least one loop line, whereby preferably one tapping point for water is connected. Preferably, a percentage distribution of 95% at the outlet and 5% passing through is achieved.

[0091] In a further embodiment of the invention, it is proposed to use a temperature control device for cooling the circulating water to transfer thermal energy from the circulating water to another material flow, preferably by means of a heat transfer agent, whereby by appropriately selecting the flow of other materials such as propane, optimization of the cooling process and reduction of the energy required for operating the cooling device can be achieved.

[0092] In a further embodiment of the invention, it is proposed that the cooling device is thermally coupled to a chiller, preferably a heat pump, a water chiller or a cold and warm supply network, whereby similarly a reduction in the energy required for the cooling process can be achieved.

[0093] In a further embodiment of the invention, the consumer characteristics of the circulation pump are determined according to the supplied volume flow rate of the circulation pump, the consumer characteristics of the cooling device are determined according to the water temperature at the output port, and the power consumption of the circulation pump and the cooling device takes a relative or absolute minimum value, whereby the volume flow rate V z and the water temperature T a at the output port are adjusted so as to improve the energy efficiency of the method.

[0094] In a further embodiment of the invention, a value of 20 °C + / - 5 °C is selected for the temperature T soll , and the water temperature T aRegarding this, it is proposed after careful consideration that a value of 15°C ± 5°C be selected.

[0095] In a further embodiment of the present invention, it is proposed that at least one partial section of the pipeline system be designed as an external circulation conduit, because external circulation conduits are usually installed, especially within an existing circulation system.

[0096] In a further embodiment of the present invention, it is proposed that at least one partial section be designed as an in-line circulation conduit, because these are often installed within a newer, or new, circulation system.

[0097] Further advantages will become apparent from the following description of the drawings.

[0098] The drawings illustrate exemplary embodiments herein. Many functions are combined and included in the drawings, the specification, and the claims. Those skilled in the art will also consider the functions individually after careful consideration and combine them into further meaningful combinations.

[0099] By way of example, the following is shown.

Brief Description of the Drawings

[0100]

Fig. 1a

Fig. 1b

Fig. 2

Figs. 3a - 3c

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Fig. 9

Fig. 10

[0101] The circulation systems shown in FIGS. 1 to 8 are merely examples, and the present invention is not limited to these systems. In all the systems shown, exactly two volume flows enter a node and one volume flow exits from there, or exactly one volume flow enters and exactly two volume flows exit from there, as in the case of a T-piece. However, the present invention is not limited to systems having such nodes. Basically, all lines represented between nodes, between a node and an input port, and between a node and an output port can be composed of one or more sub-sections (some sections) as defined above.

[0102] Like components are given the same reference numerals.

[0103] First, in order to better understand the present invention, the circulation system already described in the specification of PCT / EP2019 / 062547 is described in contrast to FIG. 1a.

[0104] In the circulation system shown in FIG. 1a, one node K1 is connected across the flow pipe 4a to the output port 12b of the cooling device 12. The cooling device 12 has connections to a cooling side and a cooling pump 13.

[0105] Node K1 is provided with a branch point to the collecting line 4, a connection line to the junction 1 in the water supply network, and a consumer line 3, and the consumer line and the connection line are not part of the circulation system. Therefore, no distribution of the volumetric flow occurs at node K1.

[0106] The collecting supply line 4 is connected to a riser pipe 5 that empties into node K2. Node K2 branches into the floor line 6 of the building and the riser pipe 5, and empties into node K3, where a branch to the floor line 6 of the building and the riser pipe 5 occurs, which is connected to the floor line 6 of the building and empties into node K4. Node K2 is connected to node K6 by the floor line 6 of the building. Node K3 is connected to node K5 by the floor line 6 of the building.

[0107] Two subsections TS1 and TS2, which are characterized explicitly as such, are connected across node K4, where TS1 represents a subsection of the floor line 6 of the building and TS2 represents a circulation conduit.

[0108] Furthermore, at node K4, a branch to a tapping point 9 occurs across a single supply line 7. For the sake of simplicity, the single supply line and the tapping point connected to nodes K2 and K3 are not labeled with reference signs. Since the circulation system according to the invention operates to implement the method according to the invention without water removal occurring, in the following, the nodes cooperating with the tapping point are not considered, and thus, except for node K4, no reference signs are shown in the drawings.

[0109] The subsection TS2 is connected to a vertical circulation conduit 10a that empties into node K5. Node K5 is connected to a circulation conduit 10a that empties into node K6. Node K6 is connected to the vertical circulation conduit 10a, and the vertical circulation conduit 10a is connected to a horizontal circulation conduit 10a, which in turn is connected to a circulation pump 10b across the vertical circulation conduit.

[0110] The circulation system according to the present invention for high-temperature drinking water PWC as shown in FIG. 1b has a structure similar to the system shown in FIG. 1a, but the reference numeral 12 indicates a heating device connected to the inlet port 12a via a connection line 4' for low-temperature drinking water PWC. The outlet port 12b is connected to the riser line 5. The reference numeral 9 indicates the last tapping point of the warm water PWH. The circulation line 10a of the circulation system PWH-C is connected to the inlet port 12a with the circulation pump 10b interposed therebetween. The heating device has a port for the heating circuit and a pump 13 for the heating circuit.

[0111] In an additional embodiment of the present invention, in FIG. 1a, a valve is provided at the node point K1, which can temporarily cut off the water supply from port 1 and can heat the drinking water, but the reference numeral 12 indicates a heating device or a temperature control device.

[0112] The circulation system shown in FIG. 2 has a structure similar to the system of FIG. 1a, but a loop line is provided on the floor line 6 of the building, and for simplicity, the reference numeral 8 is used only for the uppermost loop line shown in FIG. 2. The loop line 8 cooperates with an optional diverter 8a. The loop line cooperates from node K21 to K32. It should be understood that such a system with only one loop line is also encompassed by the present invention.

[0113] FIG. 3 shows another system having nodes K31 to K34, where the empty circulation conduits 10a at nodes K34 and K35 are led parallel to the floor line 6 of the building flowing out from nodes K32 and K33.

[0114] Furthermore, an optional decentralized cooling device 14 with an input port 14a and an output port 14b is arranged on the floor line 6 of the top floor of the building, but for simplicity of illustration, the existing junctions of the cooling side circuit and the corresponding pumps are not shown.

[0115] Similarly, additional distributed cooling devices can be arranged on the floor lines of other buildings, as shown in Figure 3a.

[0116] In another embodiment similar to Figure 3, the heat exchanger 12 can be omitted, in which case, as shown in Figure 3b, one cooling device 14 or a plurality of cooling devices 14 are required.

[0117] Similar to the embodiment of Figure 3, the cooling device can be provided on the riser pipes 5 and the floor lines of the buildings of the embodiments from Figure 1, Figure 2, and Figure 4 to Figure 8, together with, for example, the cooling device 12' as in Figure 3.

[0118] Figure 4 illustrates a system with nodes K41 to K51 as in Figure 3, but a loop line 8 is provided on the floor line of the building.

[0119] Figure 5 illustrates a system with nodes K51 to K55, but the circulation conduit 10 is led parallel to the riser pipes 5 connected to nodes K52 and K53.

[0120] Figure 6 illustrates a system with nodes K61 to K69b, where loop lines are provided between nodes K63 and K64, between K66 and K67, and between K68 and K69.

[0121] Figure 7 illustrates a system with nodes K71 to K75, where the riser pipes 5 are connected to nodes K72 and K73.

[0122] Figure 8 illustrates a system with nodes K81 to K89b similar to Figure 7, but loop lines are arranged between nodes K89a and K89b, between K88 and K89, and between K84 and K85.

[0123] Figure 9 shows a system having an apparatus 12' connected to the inlet port 12a' of the water supply 1 by line 2'. The outlet port 12b' is connected to node K91 and riser line 5 by collection line 4a.

[0124] The circulation line 10a is connected at the inlet port 12a'.

[0125] The apparatus 12' can be designed as a cooling device, a heating device, or a temperature control device.

[0126] Figure 10 shows a system having an apparatus 20 connected to the inlet port 20a' of the water supply 1 by line 2'. The outlet port 20b' is connected to node K101 and riser line 5 by collection line 4.

[0127] The circulation line 10a is connected downstream of the outlet port 20b'.

[0128] The apparatus 20 can be designed as a cooling device, a heating device, or a temperature control device.

[0129] Furthermore, the system includes an apparatus 12, and its output port 12b is connected to node K101 and riser line 5 by collection line 4a.

[0130] The circulation line 10a is connected to the inlet port 12a.

[0131] The apparatus 12 can be designed as a cooling device, a heating device, or a temperature control device.

[0132] The embodiments shown in FIGS. 1, 3, 5, and 7 are also possible where only partial regions can have circulation. Thus, a sub - section may represent, for example, residential facilities where different requirements (metering of water consumption) do not permit circulation together. Here, automatic cleaning is used to enable water exchange to maintain the desired temperature.

[0133] The method according to the invention is implemented in the system of FIGS. 1 to 8 as described above, and for the first sub-section connected to the output port (12b), the temperature starting value T MA *<T soll and the volume flow starting value V z *, starting from which, the temperature change of the water between the initial region and the end region is determined according to the model of the temperature change.

[0134] Furthermore, under the boundary condition that the water temperature in the initial region of a given sub-section is equal to the water temperature in the end region of the sub-section to which the given sub-section is connected, according to the model of the temperature change, the temperature change of the water between the initial region and the end region of each further given sub-section is determined.

[0135] Preferably, the above model of the axial temperature change is used, according to which the water temperature T ME at the end region of the sub-section of length L is calculated by the formula.

[0136] TIFF0007682543000014.tif22170

[0137] In the end region of each sub-section of the circulation system, the water temperature is T ME <T soll and at the input port 12a, the water temperature is T b <T soll and T soll -T b <θ, where the value T a of the water temperature and the value V z of the volume flow at the output port 12b are selected such that θ>0 is a given value.

[0138] It should be understood that the circulation pump 10b does not always operate at a constant volume flow rate, i.e., regardless of whether the port inlet temperature 12a has exactly the set value or is below it.

[0139] If for various reasons the port inlet temperature 12a needs to be at 17 °C, for example if a maximum of 20 °C is given, the supply volume flow rate of the circulation pump 10b can be reduced. This can be carried out automatically, for example under temperature control. As a result, energy savings are achieved.

[0140] Similarly, in such cases, the supply volume flow rate of pump 13 can be reduced by temperature control.

[0141] If for various reasons the port inlet temperature needs to be set to, for example, 17 °C (for example if a maximum of 20 °C is given), the flow temperature of the cooling circuit can be adjusted similarly. As a result, energy savings will be achieved.

[0142]

Table 1

Explanation of symbols

[0143] 1 Connection to the water supply network 2 Connection line 3 Consumer line 4a Main supply line 5 Risers (down pipes) 6 Floor lines of the building 7 Single supply line 8 Loop line 8a Static or dynamic flow splitting 9 Tapping point 10 Circulation system 10a Circulation conduit 10b Circulation pump 12 Temperature control device, cooling device, heat exchanger 12a Input port 12b Output port 13 Pump 13’ Pump 14 Temperature control device, cooling device, heat exchanger 14a Input port 14b Output port 14’ Temperature control device, cooling device, heat exchanger 15 Pump 20 Temperature control device, cooling device, heat exchanger 20a Input port 20b Output port 21 Pump 21a Input port 21b Output port

Claims

1. A method of operating a circulation system (10) having a pipeline system with a plurality of branches having one or more sub-sections having an input port and an output port, having a temperature control device for controlling the temperature of water, having a given thermal coupling to the surroundings, and being connected by nodes, wherein one or more lines of the pipeline system are configured as flow pipes (4, 5, 6), at least one is connected as a single supply line (7) to a tapping point (9), and at least one line is configured as a circulation conduit (10a) connected to one or more flow pipes (4, 5, 6), and the thermal coupling is heat transfer to the surroundings via the lines of the pipeline system, The method comprises - Using the temperature control device, setting the water temperature of the output port to value T ａ and - setting the volumetric flow rate of the input port to a value V ｚ and a method including the step of the following steps - Starting temperature value T ＭＡ ＊ and starting volume flow rate V ｚ ＊ starting from, determining the temperature change of water between the initial region and the end region according to the model of the axial temperature change of the first partial section connected to the output port - The water temperature T of the initial region of the given partial section ＭＡ is equal to the water temperature T within the end region of the partial section to which the given partial section is connected ＭＥ Under the boundary condition that they are equal, according to the model of the temperature change, determining the temperature change of the water between the initial region and the end region of each further given partial section - at the end region of each section, the water temperature T ＭＥ is within a given temperature range centered around the temperature T ｓｏｌｌ such that the value T of the water temperature at the output port ａ and the value V of the volumetric flow rate ｚ are selected, comprising the step of - at the input port, the water temperature is T ｂ < T ｓｏｌｌ is set to, and T ｓｏｌｌ - T ｂ < θ, where θ > 0 is a given value, - the temperature control device (12') having the input port (12a') is connected to the water supply device (1) by a line (2'), or - a cooling device (20) is provided, the cooling device (20) having the input port (20a) is connected to the water supply device (1) by a line (2'), and the circulation conduit (10a) is connected downstream of the output port (20b') A method characterized by the above.

2. the value T ａ and V ｚ is determined by an iterative approximation procedure, wherein, under the boundary condition that the water temperature in the initial region of the given partial section is equal to the water temperature in the end region of the partial section to which the given partial section is connected, the temperature change of the water between the initial region and the end region is the temperature start value T ＭＡ ＊ of the first partial section connected to the output port of each further given partial section, ｚ ＊ and the volume flow start value V starting from and being calculated, the method according to claim 1.

3. The method according to claim 1 or 2, characterized in that the sub-sections are designed uniformly with respect to their thermal coupling to the surroundings along the length between their initial region and their end region.

4. The water temperature T in the end region of said at least one sub-section having length L ＭＥ is given by the formula A method characterized by being determined by L = length of the partial section (T Ｓ１ )(m) T ＭＡ = water temperature (°C) of the initial region T ＭＥ = water temperature (°C) of the end region T Ｌｕｆｔ = Temperature of ambient air (°C) k Ｒ = heat transfer coefficient of the pipeline (W / (m*K)) m Ｍ = mass flow rate of water in the partial section (kg / s) C ｐ，ｍ = Specific heat capacity of water (J / (kg*K)) V Ｍ = The volumetric flow rate of water in the partial section (m ３ / s) p Ｍ = the density of the water (kg / m ３ ), the method according to claim 3.

5. The heat transfer coefficient of the sub-section is 1 / k Ｒ = the heat transfer resistance of the pipeline (m*K / W) α ｉ = Internal heat transfer coefficient (W / (m ２ * K)) 1 / ΔR = thermal resistance (m*K / W) α a = external heat transfer coefficient (W / (m ２ * K)) d a = Outer diameter (m) d ｉ = inner diameter (m), Equation and and A method according to claim 4, characterized by being determined by.

6. The method according to claim 1, characterized in that a circulation pump (10b) is integrated into the circulation system (10).

7. The parameter T determined by the method ａ and V ｚ are used to determine the design of the temperature control device with respect to the cooling capacity thereof in a given circulation system in which the pipeline system is designed in accordance with legal specifications regarding the nominal width and the thermal coupling of the circulating water to the surroundings, or the design of the circulation pump (10b) integrated into the circulation system (10) can be determined with respect to its pump output, characterized in that the method according to claim 1

8. - determining the characteristics of the circulation pump (10b) according to the supplied volume flow rate of the circulation pump (10b); - determining the characteristics of the temperature control device according to the water temperature at the output port; - The volume flow rate V at the output port is set such that the power consumption of the circulation pump (10b) and the temperature control device becomes a relative or absolute minimum value. ｚ and the water temperature T ａ The method according to claim 6 or 7, characterized by the step of setting.

9. A circulation system having a pipeline system with a plurality of branches having one or more sub-sections with input ports and output ports, having a temperature control device for cooling water, having a given thermal coupling to the surroundings, and being connected by nodes, wherein the thermal coupling is heat transfer to the surroundings via the lines of the pipeline system, - For a given distribution of the volumetric flow rate exiting the node, the mixed water temperature can be determined from the volumetric flow rate exiting the node as a function of the volumetric flow rate entering the node, - One or more lines of the pipeline system are configured as flow pipes (4, 5, 6), at least one is configured as a single supply line (7) connected to a tapping point (9), and at least one line is configured as a circulation conduit (10a) connected to one or more of the flow pipes (4, 5, 6), The circulation system has, - means for setting the water temperature at the output port to a value T by the temperature control device ａ and - means for setting the steady volumetric flow rate of the circulating water at the input port to a value V ｚ and has, The circulation system has, - The water temperature T of the end region of a given partial section ＭＥ is equal to the water temperature T within the initial region of the partial section connected to the given partial section in the flow direction of the circulating water ＭＡ Under the boundary condition of equality, device means for determining the temperature change of water between the initial region and the end region of each partial section - at the end region of each part section, the water temperature T ＭＥ is at a given temperature range centered around the temperature T ｓｏｌｌ such that at the input port, the water temperature is T ｂ < T ｓｏｌｌ is set to, and T ｓｏｌｌ - T ｂ < θ, where θ > 0 is a given value, the value T ａ of the water temperature and the value V ｚ of the volumetric flow rate at the output port, and means for selecting, - The temperature control device (12') having the input port (12a') is connected to the water supply device (1) by a line (2'), or - A cooling device (20) is provided, the cooling device (20) having the input port (20a) is connected to the water supply device (1) by a line (2'), and the circulation conduit (10a) is connected downstream of the output port (20b'), A circulation system, characterized in that.

10. The device means is provided for the values T ａ and V ｚ to be determined by an iterative approximation procedure, a circulation system characterized in that the water temperature T ＭＥ is the starting temperature value T of the first partial section connected to the output port (12b) ＭＡ ＊ < T ｓｏｌｌ and the starting value of the volume flow rate V ｚ ＊ is calculated starting from, and then the water temperature T within the initial region of the next attached partial section ＭＡ ’ is selected to be equal to the water temperature T within the end region of the given partial section ＭＥ The circulation system according to claim 9, wherein

11. The circulation system according to claim 9, characterized in that the sub-sections are designed uniformly with respect to their thermal coupling to the surroundings along the length between their initial and their end regions.

12. The circulation system according to claim 9, characterized in that a circulation pump (7) is integrated into the circulation system (10).

13. The circulation system according to claim 9, characterized in that thermal energy from the circulating water is transferred by the temperature control device by heat transfer means to another material flow. **Claim 14**: The values Ta and Vz are used to determine the design of the temperature control device with respect to the cooling capacity in a given circulation system, where the pipeline system is designed according to legal specifications regarding the nominal width and the width of the circulating water and heat coupling to the surroundings, and / or the design of the circulation pump can be determined with respect to its pump output, according to the circulation system according to claim 9.

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