EP3690151A1 - Drinking and domestic water system and method for flushing the same - Google Patents

Abstract

The present invention relates to a drinking and service water system with a connection (2) to the public water supply network, at least one supply line (4, 6) leading to at least one consumer (8), a flushing valve (10) downstream of the consumer (8) in the flow direction. for draining water from the drinking and service water system, a control unit (12) connected to the flush valve (10) in terms of control and a first temperature sensor (18) upstream of the consumer (8) in the direction of flow, the control unit (12) comprising a flush module, that specifies flushing processes for the control unit (12) at specific times and / or at specific time intervals and / or as a function of a measured temperature. The present invention aims to provide a drinking and service water system which, with an efficient flushing device, meets the hygienic requirements placed on a drinking water system. To solve the problem, a second temperature sensor (20) is arranged between the consumer (8) and the flushing valve (10) and the control unit (12) is set up for this purpose, based on a temperature difference between a measured value of the first temperature sensor (18) and a measured value of the second temperature sensor (20) to decide whether the predetermined flushing process is suspended or postponed. In a secondary aspect, the present invention specifies a method for flushing such a system.

Description

The present invention relates to a drinking and process water system with the preamble features of claim 1. Such a drinking and process water system is based on the applicant DE 20 2008 002 822 U1 known. The present invention further relates to a method for flushing such a system.

The previously known drinking and process water system has a connection to the public water supply network in the basement of a building. Via this connection, several supply lines for the supply of various water consumers within the building are fed with fresh water. If there is no water withdrawal by a consumer, stale water in the supply lines can be drained into a sewer line via a flushing valve. The flushing valve is provided at one end of the supply line or supply lines and is connected in terms of control to a central control unit. In particular, the position of the flush valve can be checked by means of a motor cable. This is usually connected indirectly via a decentralized control unit or directly to the central control unit. The central control unit usually coordinates all flushing processes in a building and evaluates the temperature signals described below. A wired connection of sensors and valves for monitoring and regulating the drinking water system can also be done via distributed controls in the building. These decentralized controls can in turn be an integral part of an overall unit, which can also contain sensors and valves. Automated flushing processes can be programmed using a time module integrated in the central control unit. In addition, a water temperature measured via a temperature sensor can be transmitted to the central control unit. Depending on the measured temperature, the period of the flushing cycles can be adjusted so that, for example, in summer, when the pipes and the water in them warm up more quickly, they are flushed at shorter intervals than in winter. Depending on the building and piping, the reverse case is also conceivable, so that in winter, due to the higher heating requirements, the drinking water also heats up more than desired and therefore has to be rinsed more frequently. The temperature has therefore turned out to be a very useful variable for flushing sensibly depending on the type of building and other external circumstances.

Out DE 10 2011 013 955 A1 or. EP 2 500 475 A2 a flushing device is known which has a temperature sensor for recording the temporal temperature profile of the water temperature contained in a drinking water pipe. If this temperature sensor records a constant temperature curve over a predetermined period of time, a flushing process is triggered by opening a flushing valve. If the temperature sensor does not record a constant temperature curve over a predetermined period of time, a flushing process is omitted by keeping the flushing valve closed.

If a drinking water pipe remains unused for a longer period of time, the temperature of the water in it will adjust to the ambient temperature. A thermal equilibrium is established between the environment and the drinking water pipe. If the ambient temperature is in the room temperature range, the formation of germs such as Legionella is favored. Flushing the drinking water pipe is then necessary with a view to drinking water hygiene.

With the flushing device after DE 10 2011 013 955A1 or. EP 2 500 475 A2 it may still be that such a flushing process is suspended. Because the adjustment of the water temperature in the drinking water pipe to the ambient temperature does not result in a constant temperature curve. Furthermore, the ambient temperature is not constant. When darkness or night falls, for example, the ambient temperature usually drops. This also lowers the temperature of the water in the drinking water pipe. The temperature profile of the drinking water in the drinking water pipe is rarely constant over a certain period of time, even if it is not used. As shown, external influences can cause the rinsing device to re-operate DE 10 2011 013 955 A1 or. EP 2 500 475 A2 misinterpreted the measured temperature curve, interpreting a deviation from a constant temperature curve as being used by a consumer and suspending a flushing process, even though the drinking water line was used insufficiently or not at all.

The prior art offers room for improvement in terms of washing efficiency.

It is therefore an object of the present invention to provide a drinking and industrial water system which, with an efficient flushing device, meets the hygienic requirements placed on a drinking water system, and a method for flushing such a system.

In order to achieve this object in terms of the device, the present invention provides a drinking and process water system with the features of claim 1.

This drinking and process water system has a connection to the public water supply network, via which at least the supply line leading to at least one consumer is fed with fresh water. The flushing valve for draining water from the drinking and industrial water system is arranged downstream of the consumer in the direction of flow and is connected in terms of control to a control unit which comprises a flushing module which flushes the control unit at certain times and / or at certain time intervals and / or depending on measured Temperatures. As a rule, the control unit controls a drive which, for. B. a valve body of the flush valve relative to a valve seat of the flush valve via an axially movable or a rotatably mounted actuator. A rinse can then be programmed into the control unit at predetermined times and / or at predetermined time intervals (for example every eight hours) and / or as a function of measured temperatures. Such preprogramming is usually referred to as a wash schedule.

Furthermore, the drinking and industrial water system has a first temperature sensor upstream of the consumer in the direction of flow. This measures the water temperature in the supply line. A second temperature sensor is arranged between the consumer and the flush valve. The control unit is set up to decide, based on a temperature difference between a measured value of the first temperature sensor and a measured value of the second temperature sensor, whether a rinsing process specified according to the rinsing schedule is carried out, omitted or postponed.

Usually, the time intervals between two rinsing processes are selected so that the water in the pipes does not develop into a critical temperature range in which bacterial formation is favored, even if a consumer does not tap. The time intervals are usually fixed. To ensure that the critical temperature range is not reached, a temperature-controlled flush can be programmed into the flushing schedule in addition or as an alternative to the purely time-controlled flushing.

Before the critical temperature range is reached, the control unit initiates a flushing process, ie opens the flushing valve and then closes it again when sufficient stagnant water has been drained from the system and replaced with fresh cold water. "Rinsing" means an exchange of water in the pipe.

Regular tapping or a single long tapping process can make a rinsing process programmed according to the flushing schedule superfluous. If it is then rinsed, water is used unnecessarily. Usually, all of the water in front of the flushing valve in the upstream pipe system is drained off.

The present invention provides a solution to this problem.

If a consumer draws water from the system, the temperature in the supply line usually drops because cold water flows in via the connection to the public water supply network. This causes a temperature difference between the measured values of the first and the second temperature sensor. This is because the second temperature sensor is arranged downstream of the consumer in the flow direction, preferably assigned to the flushing valve and / or arranged directly in front of the flushing valve. While the temperature in the area of the first temperature sensor is essentially instantaneously reduced by the direct exchange of water in the line by cold water, in the area of the second temperature sensor there is temperature compensation with the cold water which has flowed in and remains in the line after the tapping process has ended , only gradually through heat transfer (convection). The area of the second temperature sensor is usually not directly flowed through by the incoming cold water. In this respect, the processes in these two areas take place on different time scales, which means that a temperature difference between the measured values of the first and the measured values of the second temperature sensor can be determined during a tapping process. The first and second temperature sensors usually measure continuously and are connected to the control unit in terms of data. A temperature difference between the measured values of the first temperature sensor and the measured values of the second temperature sensor is usually determined in the control unit at defined time intervals, usually at most one minute. As a rule, the control unit contains a logic unit which determines a temperature difference by calculating the difference between the measured value of the first and the measured value of the second temperature sensor, the difference being logged or stored, if necessary. The calculation of the difference can preferably be carried out continuously.

In this way, the control unit can draw conclusions about the usage behavior of the consumers. These conclusions flow into the decision of the control unit as to whether a flushing process should be carried out, omitted or postponed. The invention brings about a use-oriented change in the flushing schedule. The drinking and Process water system less susceptible to external influences. This is because these affect both temperature sensors equally, so that their effects have no influence on the difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor.

The present invention thus allows hygienically safe operation of a drinking and process water system. For example, if a significant tap takes place directly before a rinsing process specified in the rinsing schedule, i.e. a larger amount of water is removed from the system by a consumer, the specified rinsing process can be dispensed with or postponed. Because the consumption-related exchange of water during a significant dispensing process ensures that sufficient fresh water flows into the system so that the subsequent rinsing process can be dispensed with in order to comply with the hygienic requirements. If the time interval to the next scheduled rinsing process is too long, the planned rinsing process and all subsequent rinsing processes can only be postponed for a certain time. The period between the individual subsequent rinsing processes is usually not changed.

A connection to the public water supply network within the meaning of the present invention is in particular a region of a drinking and process water system of a building that communicates directly with the domestic water meter, but does not yet have a branch that leads to one or more supply lines. The water drained through the flush valve is usually drained off via a sewage pipe connected to a sewage outlet. Waste water discharge in the sense of the present invention is to be understood as the pipeline area of a drinking and industrial water system of a building which transfers the waste water to the public waste water network. The connection to the public water supply network and the waste water outlet are usually located directly next to each other and at basement level. The supply line or the supply lines generally have a nominal diameter of DN 20 or larger.

According to a preferred development, the control unit is set up in such a way that the difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor is formed at predetermined time intervals and is stored in the control unit for a defined minimum period. The predetermined time intervals between two difference values are generally the same. The time interval between two difference values is preferably at most one minute. The specified minimum duration is preferably 24 hours.

According to a further preferred development of the present invention, the control unit is set up in such a way that a rinsing process specified according to the rinsing plan can be suspended or shifted if the difference before the planned start time of the specified rinsing process is at least 2.5 ° C., preferably at least 3 ° C., very preferred is at least 3.5 ° C and particularly preferably at least 4 ° C. If a difference is calculated that corresponds to these values, a significant tap operation is concluded.

According to a further preferred development of the present invention, the control unit is set up in such a way that the duration of a dispensing operation can be determined from the time course of the difference. The start time of a tap is usually the time from which the difference increases. Accordingly, the end time of the dispensing process is usually the time from which the difference decreases. The fact that the difference decreases again after a tap is due to the fact that the water temperature in the pipe gradually balances out due to heat transfer. The duration of the tap is the time between the start and the end of the tap.

According to a further preferred development of the present invention, the control unit is set up in such a way that a predetermined flushing process can be suspended or shifted if the sum of the duration of all, preferably significant dispensing processes reaches or exceeds a defined limit value in a specific time interval before the planned start time of a specified flushing process . The specific time interval before the planned start time can be, for example, one hour. The exact time interval is preferably adjustable and stored in the control unit. The limit value is also usually stored in the control unit and is preferably adjustable.

In this way, the decision of the control unit as to whether enough water has been exchanged due to the usage behavior of the consumers can be improved. If the control unit decides that enough water has been exchanged based on the usage behavior, it suspends or postpones the next scheduled flushing process.

According to a further preferred development of the present invention, at least two consumers are connected to the supply lines, a further temperature sensor being arranged between these consumers. In this way, a usage profile can be created for each individual consumer. The further temperature sensor fulfills the function of the first temperature sensor for the consumer downstream of it.

According to a further preferred development of the present invention, the supply line comprises at least one storey line and several storey lines. The floor string usually extends vertically over one or more floors. A floor string usually does not extend beyond a single floor. At least one consumer and a temperature sensor upstream of the consumer in the flow direction are arranged in each tier. This means that a usage profile can be created for each individual floor. A flush valve is further preferably provided at the end of each tier, so that the individual floors can be flushed differently depending on the use.

The connection of the consumers to the supply line can be provided in a variety of ways. For example, several consumers can be connected to the supply line via a flow divider. The connection can just as well be implemented via a T-piece installation or a ring installation. A supply line looped through between the connection to the public water supply network, the consumers and the flushing valve as a looped through floor installation is also conceivable.

A free drain is usually provided in the area of the water outlet. The free flow is usually characterized by the fact that water covers a fall in the gravitational field of the earth, which either runs directly in the surrounding atmosphere or is atmospherically connected to it. This can prevent a possible backflow within a sewage pipe from entering the supply pipe. An overflow monitoring device is usually also provided in the area of the free flow. This generally communicates with the control unit and / or a flow rate limiter assigned to the flushing valve, so that in the event of an impending overflow at the free outlet, the flow rate from the drinking and process water system can be regulated or reduced or even completely prevented. Additionally or alternatively, the overflow monitor can issue a warning signal, for example optically or acoustically, and / or report it to a higher-level building management system.

According to a further preferred development, the control unit is set up in such a way that the difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor is compared in the control unit with a reference value. The reference value can be a constant or a stored difference, determined at an earlier point in time, between the measured value of the first temperature sensor and the measured value of the second temperature sensor. The reference value can also be a Reference temperature difference, which corresponds to an average or a median of a plurality of difference values. The control unit is set up in such a way that the predetermined rinsing process is suspended, shifted or interrupted if the difference is greater than the reference value.

The reference value is preferably a constant, for example 2.5 ° C., 3 ° C., 3.5 ° C. or 4 ° C.

According to an alternative preferred development, the reference value is a stored difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor. For the comparison between the difference and the reference value, for example, the determined difference at the same time on the previous day can be defined as the reference value.

According to a further, alternative preferred development, the reference value is a reference temperature difference which corresponds to the median of a large number of difference values. The median is preferably formed from difference values determined at an interval of one hour. For example, the last 23 difference values measured every hour on the hour can be used to calculate the median.

According to a further, alternative preferred development, the reference value is a reference temperature difference which corresponds to the mean value from a large number of difference values. The oldest difference value that is included in the calculation of the mean value is preferably at most 24 hours old at the time of the calculation. The mean value is further preferably calculated at a preset time and usually stored until it is replaced or overwritten on the following day by the mean value again calculated at the preset time.

According to a further alternative preferred development, the reference value is a reference temperature difference which corresponds to the mean value from a multiplicity of difference values, the mean value being formed from the determined difference values of the previous day.

To solve the procedural problem, the present invention provides a method for flushing a drinking and process water system. In this case, a temperature difference is formed between a temperature measured in an area in front of a flush valve and a temperature in an area in front of a consumer, on the basis of which a Control unit decides whether a flushing process is carried out, omitted or postponed. Performing is understood to mean, in particular, starting or continuing. Failure to do so is, in particular, to be understood to mean stopping or not starting.

The area in front of the consumer is usually a line section that extends between the consumer and a connection to the public water supply network. The area in front of the flushing valve is usually to be understood as a line section which extends between the flushing valve and the consumer. A temperature sensor for measuring the temperature is usually provided in each of these areas. A first temperature sensor is preferably assigned directly to the consumer and a second temperature sensor is assigned directly to the flush valve.

A flushing module of the control unit usually specifies the opening of the flushing valve at certain times and / or at certain time intervals and / or as a function of measured temperatures. The difference between the measured values of the first and second temperature sensors is usually formed. This can be formed as a function of time by measuring at discrete time intervals or by continuous measuring and preferably stored. The time period to be taken into account for the decision about the rinsing is preferably adjustable.

The method according to the invention is preferably designed according to one or more of the developments discussed above.

Further details and advantages of the present invention result from the following description of an exemplary embodiment in connection with the Figure 1 , which shows a schematic representation of an embodiment of the drinking and industrial water system according to the invention.

The Figure 1 shows a schematic representation of an embodiment of a drinking and process water system of a building, not shown. The building's drinking and process water system has a connection 2 to the public water supply network in order to supply the building with fresh water. This fresh water is usually cold water. A supply line, which comprises a floor string 4, is fed via the connection 2. The floor string 4 extends in the vertical direction from the basement or ground floor to a second floor. The first and second floors are each supplied with water by a floor line 6, which is connected to the floor line 4 and runs horizontally in the respective floor. On every floor three consumers 8 are connected to the storey line 6 via a ring installation. A flushing valve 10 is arranged at the end of the storey branch 6 downstream of the consumers 8 in the flow direction. The purge valves 10 are connected to a control unit 12 for control purposes.

The control unit 12 contains a time module that specifies the control unit 12 times at which the control unit opens the flushing valves 10. When the flush valves 10 are open, water flows out of the drinking and process water system via a free outlet 14 into a waste water line 16. In the storey line 6, a first temperature sensor 18 is arranged upstream of the consumers 8 in the flow direction before the ring installation. The first temperature sensor 18 measures the water temperature in the storey line 6 in front of the consumers 8 and sends the measured temperature to the control unit 12. By tapping a consumer 8, fresh cold water flows from the connection 2 via the storey line 4 into the storey line 6. The flowing fresh cold water is usually at a lower temperature than the stale water that is already in the tier. The measured temperature of the first temperature sensor 18 therefore generally drops in the event of a tap operation by a consumer 8. A second temperature sensor 20 is assigned to the flushing valve 10 and upstream of this directly in the flow direction. The second temperature sensor 20 also continuously measures the water temperature and sends the measured values to the control unit 12. The measured temperature of the second temperature sensor 20 generally changes during a tap operation of a consumer 8 on a different time scale than that of the first temperature sensor 18, since the Line section in which the second temperature sensor 20 is located is not directly flowed through by the fresh cold water, as is the case with the first temperature sensor 18. The control unit 12 can therefore use an integrated logic to determine that a temperature difference between the first temperature sensor 18 and the second temperature sensor 20 occurs when a consumer 8 taps. If the temperature difference exceeds a presettable limit value, for example 4 ° C., the control unit can suspend or shift a rinsing process specified by the time module. The control unit 12 can be set up in such a way that a plurality of such dispensing processes, in which the limit value is exceeded, have to be registered in a fixed time window of, for example, 4 hours before the planned start time of a specified flushing process in order to decide that the specified flushing process is suspended to be moved.

Two further temperature sensors 22, which are each arranged between two consumers 8, are provided in the row of floors 6 on the first floor. The further temperature sensors 22 also continuously measure the water temperature and send the measured values to the control unit 12. The control unit 12 can compare the measured values of the further temperature sensors 22 with the measured temperatures of the second temperature sensor 20 in order to have a separate usage profile for each individual consumer 8 to create.

Reference list

2nd

Connection to the public water supply network

4th

Floor string

6

Floor string

8th

consumer

10th

Flush valve

12th

Control unit

14

free flow

16

Sewer pipe

18th

first temperature sensor

20

second temperature sensor

22

further temperature sensor

Claims (15)

Drinking and industrial water system with a connection (2) to the public water supply network, at least one supply line (4, 6) leading to at least one consumer (8), a flushing valve (10) downstream of the consumer (8) in the flow direction for draining water the drinking and industrial water system, a control unit (12) connected to the flushing valve (10) in terms of control, and a first temperature sensor (18) upstream of the consumer (8) in the flow direction, the control unit (12) comprising a flushing module which the control unit (12 ) Specifies rinsing processes at specific times and / or at specific time intervals and / or as a function of a measured temperature,
characterized,
that a second temperature sensor (20) is arranged between the consumer (8) and the flushing valve (10) and that the control unit (12) is set up based on a temperature difference between a measured value of the first temperature sensor (18) and a measured value of the second Temperature sensor (20) to decide whether the specified rinsing process is carried out, omitted or postponed. Drinking and industrial water system according to claim 1, characterized in that the control unit (12) is set up to form a difference between the measured value of the first temperature sensor (18) and the measured value of the second temperature sensor at predetermined time intervals and to store it for a defined minimum duration . Drinking and industrial water system according to claim 2, characterized in that the control unit (12) is set up to determine a duration of a tap operation from the time course of the difference. Drinking and industrial water system according to claim 3, characterized in that the control unit (12) is set up in such a way that a predetermined flushing process can be suspended or shifted if the sum of the duration of all dispensing processes in a specific time interval before a planned start time for the specified flushing process Limit reached or exceeded. Drinking and industrial water system according to one of the preceding claims, characterized in that at least two consumers (8) are connected to the supply line (4, 6) and that a further temperature sensor (22) is arranged between these consumers (8). Drinking and process water system according to one of the preceding claims, characterized in that the supply line (4, 6) comprises at least one storey branch (4) and several storey branches (6) and that in each storey branch (6) at least one consumer (8) the temperature sensor (18) upstream of the consumer (8) and a flushing valve (10) downstream of the consumer (8) are arranged. Drinking and industrial water system according to one of claims 2 to 6, characterized in that the control unit is set up to compare the difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor with a reference value and to suspend, shift or cancel if the difference is greater than the reference value. Drinking and industrial water system according to claim 7, characterized in that the reference value is a constant, in particular 2.5 ° C, 3 ° C, 3.5 ° C or 4 ° C. Drinking and industrial water system according to claim 7, characterized in that the reference value is a reference temperature difference which corresponds to a stored difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor. Drinking and industrial water system according to claim 7, characterized in that the reference value is a reference temperature difference which corresponds to the median of a plurality of difference values. Drinking and industrial water system according to claim 7, characterized in that the reference value is a reference temperature difference which corresponds to the average of a plurality of difference values. Drinking and industrial water system according to claim 11, characterized in that the oldest difference value, which is included in the calculation of the mean value, was at most 24 hours ago. Drinking and industrial water system according to claim 12, characterized in that the average is calculated at a preset time. Drinking and industrial water system according to claim 11, characterized in that the mean value is formed from the determined values of the previous day. Method for flushing a drinking and process water system, in which a temperature difference is formed between a temperature measured in a region in front of a flush valve and a temperature in a region in front of a consumer, on the basis of which a control unit connected to the flush valve in terms of control decides whether a flushing process carried out, omitted or postponed.

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