Abstract
A water circulation system having a feed line, a return line, a string that connects the feed line to the return line is disclosed. A temperature control unit connects the feed line to the return line, a consumer, a valve, at least one temperature sensor and a system control. A method is disclosed which includes the steps of determining a first temperature, a second temperature and a lowering time; detecting the water temperature; controlling the first temperature by controlling the valve; and controlling the second temperature by controlling the valve during the lowering time.
Claims
1: A method for operating a water circulation system, comprising the steps of: providing the water circulation system, comprising: at least one feed line (1), at least one return line (2), at least one strand (3), which connects the feed line (1) to the return line (2), at least one temperature control unit (4), which connects the feed line (1) to the return line (2), whereby water can circulate in a flow direction from said at least one feed line (1), through said at least one strand (3) and said at least one return line (2) back to said feed line (1), at least one consumer (5), which is arranged along the at least one strand (3) and with which water can be taken from the circulation system, at least one valve (6) with which the flow rate of the water in the circulation system can be changed, at least one temperature sensor (60,61,62) with which the water temperature in a line section can be detected, at least one system control with which the data of the temperature sensors (60,61,62) can be processed and with which the at least one valve (6) can be actuated; defining a first temperature (T.sub.1); defining a second temperature (T.sub.2); defining a lowering time (A); detecting the water temperature with the at least one temperature sensor (60,61,62); Setting the first temperature (T1) by setting a first flow rate (D.sub.1) with the at least one valve (6); setting the second temperature (T.sub.2) by setting a second flow rate (D.sub.2) with the at least one valve (6) during the lowering time (A).
2: The method according to claim 1, comprising the steps of: defining a time window (Z.sub.F); defining a minimum temperature difference; calculating the absolute difference between the detected water temperature and the first temperature (T.sub.1); setting the second temperature (T.sub.2) if the absolute difference is less than or equal to the minimum temperature difference; detecting the time during which the second temperature (T.sub.2) is set; setting the first temperature (T.sub.1) if the absolute difference is greater than the minimum temperature difference or if the total time during which the second temperature (T.sub.2) is set is greater than the lowering time (A).
3: The method according to claim 1, comprising the steps of: defining a time window (Z.sub.F); defining a threshold value (V.sub.0); calculating the absolute difference between the detected water temperature and the first temperature (T.sub.1); integrating the difference during the time window (Z.sub.F); setting the second temperature (T.sub.2) if the integral is less than or equal to the threshold (V.sub.0); detecting the time during which the second temperature (T.sub.2) is set; setting the first temperature (T.sub.1) if the integral is greater than the threshold (V.sub.0) or if the total time during which the second temperature (T.sub.2) is set is greater than the lowering time (A).
4: The method according to claim 1, comprising the step of: defining a time period (Z.sub.R), wherein the second temperature (T.sub.2) is only set if the current time is within the time period (Z.sub.R).
5: The method according to claim 5, wherein the time window (Z.sub.F) is larger in the boundary areas of the time period (Z.sub.R) than in its central area.
6: The method according to claim 4, wherein several time periods (Z.sub.R) are provided distributed over one day, wherein the second temperature (T.sub.2) is the same, partially different or different in all time periods (Z.sub.R).
7: The method according to claim 1, comprising the steps of: recording a temperature curve of the detected water temperatures; assigning a specific consumption (V.sub.1,2,3) to the recorded temperature curve during a time interval (I.sub.1,2,3).
8: The method according to claim 1, comprising the steps of: defining at least one trigger threshold; detecting a time interval (I.sub.1,2,3) during which the at least one trigger threshold is exceeded; assigning a specific consumption (V.sub.1,2,3) to the recorded time interval (I.sub.1,2,3).
9: The method according to claim 7, comprising the step of: scaling of the integral based on specific consumption.
10: The method according to claim 1, comprising the steps of: recording a temperature curve of the detected water temperatures; adjusting the time window (Z.sub.F), the threshold value (V.sub.0), the second temperature (T.sub.2), the lowering time (A) or the time period (Z.sub.R) based on the recorded temperature curves.
11: The method according to claim 1, wherein the at least one valve (6) is connected downstream of the at least one consumer (5) in the flow direction.
12: The method according to claim 1, wherein the water circulation system comprises a hot-water circulation having at least one temperature control unit (4) which can supply heat to the circulation system and/or wherein the water circulation system comprises a cold-water circulation having at least one temperature control unit (4) which can extract heat from the circulation system.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0054] Exemplary embodiments of the present invention are explained in more detail below using figures. These serve only for explanation and are not to be interpreted restrictively, wherein:
[0055] FIG. 1 shows a schematic diagram of a water circulation system;
[0056] FIG. 2 shows a schematic diagram of a continuous lowering cycle according to the invention;
[0057] FIG. 3 shows a schematic diagram of a composite lowering cycle according to the invention; and
[0058] FIG. 4 shows a schematic diagram of a temperature curve in a strand of the system shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0059] FIG. 1 shows a schematic diagram of a water circulation system for carrying out the method according to the invention. The system comprises a feed line 1, a return line 2, two strands 3 connecting the feed line 1 with the return line 2. The system further comprises a temperature control unit 4, which connects the feed line 1 to the return line 2, allowing water to circulate in one direction from the feed line 1, via the two strands 3, the return line 2 and the temperature control unit 4 back to the feed line 1. The system also comprises several consumers 5, which are arranged along the strands 3 and with which water can be taken from the circulation system. In each strand 3, a valve 6 is provided, which is located in the area of strand 3, which opens into the return line 2. This means that the valve 6 is located in the area of the end of strand 3. With each valve 6 the flow rate of the water in the respective strand can be changed. By changing the flow rate, the temperature can be changed. The higher the flow rate, the closer the temperature of the water in strand 3 is to the temperature of the temperature control unit. A temperature sensor 60 is provided in the feed line 1, in the area of the temperature control unit 4, with which the flow temperature T.sub.V can be detected. In strand 3, in the area of the valve 6, a further temperature sensor 61 is provided, with which the strand temperature T.sub.S can be detected. In the return line 2, in the area of the temperature control unit 4, a further temperature sensor 62 is provided, with which the return temperature T.sub.R can be detected. Furthermore, the system comprises a control unit (not shown) for each strand or for the entire system, with which the data from the temperature sensors can be processed and with which the at least one valve can be actuated. A circulation pump 7 is provided in the return line 2, with which water can be transported from the strands 3 via the return line 2 to the temperature control unit 4. A non-return valve 8 is provided between pump 7 and the temperature control unit 4, which prevents water from flowing back from temperature control unit 4 to pump 7. A supply line leads from the public water connection to the temperature control unit 4. In the supply line there is a filter 9 which can clean the tap water from the public connection. Between the filter 9 and the public connection a non-return valve 8 is provided, which prevents water from the temperature control unit 4 from flowing back to the public connection.
[0060] FIG. 2 shows a schematic diagram of a continuous lowering cycle according to the invention. In the simplest case of the method for operating a water circulation system, the valve 6 is set in normal operation so that the first temperature T.sub.1 is reached. During the lowering time A, the valve 6 is set in such a way that the second temperature T.sub.2 is reached. The temperature difference between the first and the second temperature can amount to 10° C. and the lowering time 8 hours. The lowering time can start at 10 pm and therefore ends at 6 am the following day. In a further development of the method, a time window Z.sub.F precedes the lowering time A. In this time window Z.sub.F, the temperature curve is used to draw conclusions about the consumption. Alternatively, a flow meter can be used to determine the consumption. If the measured temperature in the time window Z.sub.F falls below a specified value, the temperature is not lowered. Only if the temperature measured during the time window is never below the specified value, the temperature is lowered. Alternatively, the difference between the first temperature and the measured strand temperature over the time window can be integrated. If the integral exceeds a threshold value V.sub.0, the temperature is not lowered. If the value is below, the temperature is lowered during the lowering time.
[0061] FIG. 3 shows a schematic diagram of a composite lowering cycle according to the invention. In contrast to the contiguous lowering cycle in FIG. 2, the temperature lowering is interrupted as soon as consumption becomes too high. The lowering time is interrupted if the temperature measured in the strand is too low or if the temperature difference between the first temperature and the strand temperature integrated over the time window reaches or exceeds the threshold value. In the diagram shown, consumption remains below the threshold value V0 during the time window, whereupon the temperature is lowered from the first temperature T.sub.1 to the second temperature T.sub.2. After a first lowering time A.sub.1, consumption exceeds the threshold value V.sub.0, whereupon the temperature is raised again to the first temperature. If the consumption drops below the threshold value again, the consumption is determined again during the time window. If it remains below the threshold value, the temperature is lowered again at the end of the time window. This cycle is repeated until the sum of all lowering times corresponds to the preset lowering time. This cycle can be repeated at will throughout the day. The temperature transitions can be taken into account by integrating the temperature difference of the first temperature to the measured temperature over time. For a predetermined lowering of 10° C. during 8 hours, the total integral would be 80° C..Math.h. Thus, the lowering time could be extended if the temperature decrease is smaller. Theoretically, this would be 16 hours at 5° C. Alternatively, the boundary areas can be neglected and only the times during which the second temperature is measured are taken into account. In another alternative, the time is taken into account during which the measured temperature falls below a predetermined temperature in a hot-water system or exceeds it in a cold-water system. Such a trigger threshold can be defined in such a way that, for example, smaller temperature fluctuations are ignored and the time of the temperature decrease is only considered when the trigger threshold is exceeded. The trigger threshold can be 0.1° C., 0.2° C., 0.4° C., 0.5° C., 1° C., 1.5° C., 2° C., 2.5° C., 3° C. or more. The trigger threshold can also be used to detect a specific consumption. The time during which the trigger threshold is exceeded is measured. Very short times, i.e. times below 5 seconds, can be ignored. If the time is between 5 and 15 seconds, it can be concluded that, for example, someone is washing their hands at a sink. For example, a time of 30 seconds to 15 minutes can indicate that a shower is taking place and a time of 10 to 30 minutes can indicate that a bath is being run.
[0062] In a further development, an additional time period can be defined in which the reduction is allowed at all. For example, the reduction can only be permitted from 10 pm to 6 am on the following day. The water temperature of all strands is then always set to the first temperature outside of the period and can be lowered to the second temperature if this is permitted as described above.
[0063] FIG. 4 shows a schematic representation of a temperature curve in a strand of the system during specific consumptions V.sub.1,V.sub.2,V.sub.3. If the strand temperature T.sub.S changes only slightly during a short interval I.sub.1, this can be assigned to a hand washing V.sub.1. A larger change in temperature over a longer interval I.sub.2 can be attributed to showering V.sub.2 and a large change in strand temperature over a long interval I.sub.3 can be attributed to running a bath V.sub.3. The recording of the temperature curve can be designed in such a way that it only takes place when the measured temperature in the strand exceeds the trigger threshold, i.e. the deviation from the set temperature exceeds a certain value. Alternatively, as described above, the time during which the trigger threshold is exceeded can be measured to determine a specific consumption V.sub.1,V.sub.2,V.sub.3. The time interval during which the trigger threshold is exceeded can therefore be used to detect the specific consumption. A very short interval can be ignored. A short interval indicates a hand washing, a longer interval indicates a shower and a long interval indicates a bath. Several trigger thresholds can also be determined so that the determination is not based on time alone, i.e. on the length of the intervals. It can thus be determined during which time which trigger threshold is exceeded. If only the first trigger threshold is exceeded, this indicates hand washing. If the first trigger threshold is exceeded during a first interval and a second trigger threshold is exceeded during a second interval, wherein the first trigger threshold is smaller than the second and wherein the first interval is longer than the second, this indicates a shower. Thus, any number of trigger thresholds and intervals can be combined and compared for evaluation. The preset strand temperature can also be used as trigger threshold.
TABLE-US-00001 LIST OF REFERENCE NUMERALS 1 Feed line 2 Return line 3 Strand 4 Temperature control unit 5 Consumer 6 Valve 60 Temperature sensor 61 Temperature sensor 62 Temperature sensor 7 Pump 8 Non-return valve 9 Filter I1, 2, 3 Interval T.sub.V Flow temperature T.sub.S Strand temperature T.sub.1, 2, 3 Temperature ΔT Temperature difference T.sub.R Return temperature D.sub.1, 2 Flow rate Z.sub.R Time period Z.sub.F Time window V.sub.1, 2, 3 Consumption V.sub.0 Threshold value A Lowering time A.sub.1, 2 Lowering time fragment
