Laundry system with optimized utilization of applied energy

Abstract

The invention relates to a laundry system (100) for the energy-reduced treatment of laundry and to a method for operating the laundry system (100), comprising a plurality of laundry treatment machines (10, 11, 12) to which fresh water (13) is supplied and which generate wastewater (14). According to the invention, a central fresh water warm tank (15) is provided, in which warm fresh water (13) can be stored to supply the laundry treatment machines (10, 11, 12). Furthermore, a central wastewater collection tank (16) is provided, in which warm wastewater (14) from the plurality of laundry treatment machines (10, 11, 12) can be stored. And a central heat exchanger (17) is provided, through which the warm wastewater (14) and fresh water (13) can flow, so that heat can be transferred from the wastewater (14) to the fresh water (13).

Description

[0001] The invention relates to a laundry system for energy-reduced laundry treatment, comprising a plurality of laundry treatment machines to which fresh water is supplied and which generate wastewater. The invention further relates to a method for operating such a laundry system for energy-reduced laundry treatment. STATE OF THE ART

[0002] DE 10 2006 020 003 A1 discloses a laundry system for energy-reduced laundry treatment, comprising several laundry treatment machines, wherein the thermal energy resulting from the exhaust air emitted by the laundry treatment machines, the so-called vapor, is fed to a common heat exchanger. This energy from the exhaust air is converted into warm water or warm air in the form of fresh water or fresh air. According to the disclosure, a central heat exchanger is provided for this purpose, into which the moist, warm exhaust air from the laundry treatment machines is fed. Water is heated via a water circuit at the drying point of the moist, warm exhaust air in order to then heat cold fresh water via this heated water in a closed water circuit. Disadvantageously, no use is made of the thermal energy from the warm wastewater from the laundry treatment machines, the use of which should be controlled and optimized as far as possible.A simple heat exchange is generally not sufficient, since the laundry treatment machines are operated intermittently and the waste heat is therefore only available for a limited time. However, it is always desirable to have the heat energy available at the required time to operate the laundry treatment machines at the time of commissioning. DISCLOSURE OF THE INVENTION

[0003] The object of the invention is to further reduce the energy required for laundry systems with multiple laundry treatment machines, to which fresh water is supplied and which generate hot wastewater. In particular, a method for operating such laundry systems with multiple laundry treatment machines is to be improved by designing them with an overall lower energy requirement. The reduced energy requirement should result in particular from at least the wastewater, and preferably also the exhaust air, being released into the environment at significantly lower temperatures. In this case, the energy already available in the supply of fresh water by the supplier should also be used to particular advantage.

[0004] This object is achieved by a laundry system according to the preamble of claim 1 and by a method according to the preamble of claim 12 with the respective characterizing features. Advantageous developments of the invention are specified in the dependent claims.

[0005] The invention includes the technical teaching that a central fresh water warm tank is set up in which warm fresh water can be stored to supply the plurality of laundry treatment machines, furthermore it is provided to set up a central waste water collection tank in which warm waste water from the plurality of laundry treatment machines can be stored, and a central heat exchanger is to be set up through which the warm waste water and fresh water can flow, so that heat can be transferred from the waste water to the fresh water.

[0006] The core concept of the invention is the central and direct heat exchange of the heat from the warm wastewater generated by the operation of several laundry treatment machines with the fresh water from the usually municipal fresh water supplier. This heats the fresh water directly from the fresh water supplier and ultimately flows into the central fresh water warm tank. The fresh water warm tank is filled by the system pressure of the fresh water from the fresh water supplier, which is provided via the fresh water line and thus by the supplier. The system pressure from the supplier is sufficient to conduct the fresh water through the central heat exchanger and ultimately fill the central fresh water warm tank.The wastewater passing through the heat exchanger cools down during the heat transfer and can then be fed into a sewer. Further process steps for wastewater treatment are not discussed here, but these can be provided.

[0007] A key advantage is that a cold fresh water tank is eliminated, allowing the laundry system to be designed without a cold fresh water tank. The utility's system pressure via the fresh water line is sufficient to force the cold fresh water through the heat exchanger, which then flows into the hot fresh water tank. In other words, the municipal or private water supplier forms the fresh water reservoir.

[0008] For proper operation, and especially for heating the fresh water to the desired temperature and transferring it to the fresh water warm tank, a wastewater buffer tank can preferably be installed downstream of the laundry treatment machines. This buffer tank temporarily stores the wastewater from multiple laundry treatment machines, and then transfers the warm wastewater to the wastewater collection tank via a controllable pump. The wastewater buffer tank can also be configured as a sump tank for the controllable pump on the building side. This allows the fill level of the wastewater collection tank to be adjusted, especially if the wastewater from the wastewater collection tank is ultimately fed to the central heat exchanger via a controlled pump.The supply is provided by a regulated pump with a control system that directs a volume flow of warm wastewater through the central heat exchanger, which is set so that the resulting heating of the fresh water falls within the desired temperature range. The installation of a pump for filling the central wastewater collection tank and a pump for emptying the wastewater collection tank has the advantage that the desired fill level in the wastewater collection tank can always be maintained, particularly when utilizing the wastewater buffer tank.

[0009] A particular advantage is achieved when the heat exchanger is formed by a coaxial tube heat exchanger. Coaxial tube heat exchangers have an inner tube and an outer tube, with the inner tube being coaxially inserted within the outer tube. The warm wastewater can flow through the inner tube, while the cold freshwater flows through the outer tube and is heated; reverse flow is also conceivable. The flow preferably occurs according to the countercurrent principle, so that the two flow directions of the fluids oppose each other. The heat exchanger can be particularly advantageously designed in a helical shape and can be arranged around the freshwater hot tank and / or the wastewater collection tank. The geometric design of the heat exchanger can, for example, be 3000 mm high and 1800 mm in diameter.It is also conceivable to provide at least two or more heat exchangers with this or a different geometry, through which the flow occurs either sequentially or in parallel. For example, a first heat exchanger can be arranged around the fresh water tank and a second heat exchanger around the wastewater collection tank, thus achieving a particularly space-saving arrangement and design of the heat exchanger.

[0010] As a component of the laundry system, at least one section of a fresh water line is provided, from which fresh water from an external supplier can be fed to the heat exchanger. A line connection is also provided from the fresh water line into the fresh water warm tank, in particular for emergency operation. The fresh water line is pressurised on the supplier side, so that this pressure is sufficient not only to transport the fresh water through the heat exchanger and finally into the fresh water tank, but a type of bypass line in the form of a line connection is also provided for emergency operation, so that the cold fresh water can also be fed directly from the fresh water line into the fresh water warm tank. The line connection is used for emergency operation, in which a throttle can be installed to manually or automatically adjust the volume flow of the line connection serving as a bypass.However, the transfer of cold fresh water via the pipe connection directly into the fresh water warm tank can also serve to influence the temperature in the fresh water warm tank directly and in short time cycles, especially if the temperature is too high due to fresh water that has entered the fresh water warm tank via the heat exchanger and the temperature needs to be reduced in a short time.

[0011] Particularly advantageously, a first valve arrangement is installed in the fresh water line, with which the volume flow from the fresh water line into the fresh water warm tank can be influenced. The line connection that leads from the fresh water line directly into the fresh water warm tank is also arranged on the valve arrangement. The first valve arrangement can be operated manually by an operator or by means of a control unit, in particular remotely by electric motor or pneumatically, and the valve arrangement particularly advantageously forms a flow control valve in order to regulate the volume flow in the line connection from the supplier side to the fresh water warm tank. The control of the valve arrangement can be provided via a control unit, which will be discussed later.

[0012] The first valve arrangement serves to regulate the volume flow through the fresh water line to the heat exchanger and thus also to the fresh water warm tank. The valve arrangement can also be used to regulate the volume flow into or through the line connection past the heat exchanger directly into the fresh water warm tank. The valve arrangement, particularly in the form of the flow control valve, can be designed as a 2 / 3 control valve.Only by arranging this first valve arrangement is it possible to easily utilize the supplier-side system pressure in the pipe connection so that the desired amount of fresh water reaches the fresh water warm tank. The standard case is that the fresh water is heated in the heat exchanger to the desired fresh water temperature that the fresh water warm tank should have. For emergency operation or to further regulate the temperature of the fresh water in the fresh water warm tank, the fresh water can also be fed directly into the fresh water warm tank via the pipe connection. The first valve arrangement in the form of a flow control valve, in particular designed as a 3 / 2-way control valve, can serve these control tasks.

[0013] A fresh water warm line is installed between the heat exchanger and the fresh water warm tank, via which the fresh water can flow from the heat exchanger and consequently from the fresh water line into the fresh water warm tank. According to a further embodiment of the laundry system according to the invention, a condensation heat exchanger is installed in this fresh water warm line. The condensation heat exchanger serves in particular to further heat the fresh water to the temperature required in the fresh water warm tank. For this purpose, exhaust air generated during operation of the laundry treatment machines can be fed into the condensation heat exchanger, so that heat from the exhaust air, initially referred to as vapor, can be transferred to the fresh water already heated in the heat exchanger, thus further heating it.The condensation heat exchanger can be designed in such a way that the water vapor in the moist, hot exhaust air condenses in the condensation heat exchanger, releasing energy that can be transferred to the fresh water.

[0014] The fresh water is further heated via the condensation heat exchanger from the heat exchanger along the fresh water warm line, and reaches the fresh water warm tank at the required temperature, preferably when the temperature of the fresh water is not reached by the heat exchanger. This can occur, for example, if the laundry treatment machines have not produced warm wastewater for an extended period of time, but are currently operating, for example, and immediately generate hot, humid exhaust air. It is also conceivable that the condensation heat exchanger could at least partially or completely replace the heat exchanger operated via the wastewater, at least temporarily.

[0015] It should be noted that at least some of the laundry treatment machines require superheated steam to operate, which can be drawn from a provided steam storage tank. It can also be provided that the water in the steam storage tank can also be heated using the heat exchanger and / or the condensation heat exchanger, i.e., in parallel with or in addition to the fresh water. In particular, a portion of the heated fresh water, preferably after passing through the condensation heat exchanger, can be fed into the steam boiler, stored there, and further heated, in particular, using additional heat sources.

[0016] It is even more advantageous to have a second valve arrangement in the fresh water hot line, via which cold fresh water from the fresh water line can be mixed with the fresh water heated by the condensation heat exchanger before this water is transferred to the fresh water hot tank. The second valve arrangement, which can also be designed as a flow control valve, can be used to regulate the addition of cold fresh water so that the desired temperature in the fresh water hot tank can be maintained. For the addition of fresh water via the second valve arrangement, a second, independent fresh water line can be led directly to the valve arrangement in order to supply cold fresh water from the supplier to the second valve arrangement. The first valve arrangement is therefore located in the fresh water line before it then leads to the heat exchanger.After the heat exchanger, the condensation heat exchanger follows in the fresh water hot line, in which the second valve arrangement is then also located, before the twice heated fresh water leads into the fresh water hot tank.

[0017] Furthermore, the laundry system comprises a control unit configured at least for controlling and / or regulating the first valve arrangement and / or for controlling and / or regulating the second valve arrangement. To control the first and / or second valve arrangement, the control unit can, for example, use the temperature and / or fill level in the fresh water warm tank as a reference variable. Furthermore, the control unit can be configured to control at least one of the pumps, in particular to control the speed of the pumps and, thus, the delivery rate of the pumps.

[0018] Thus, the fresh water warm tank can have a temperature measuring device which is configured to output a temperature measured value to the control unit and / or it is provided that a temperature measuring device is arranged in the fresh water line leading into the fresh water warm tank, which is configured to output a temperature measured value to the control unit.

[0019] Thus, with further advantage, the control unit is configured to control a first pump for conveying a specific volume flow from a wastewater buffer tank into the wastewater tank and / or to control a second pump for conveying a specific volume flow from the wastewater tank into the heat exchanger and / or to control at least a third pump for conveying a specific volume flow of warm fresh water from the warm fresh water tank to the multiple laundry treatment machines, wherein each of the laundry treatment machines can also be assigned its own pump. The volume flow for controlling the pumps can be determined via the control unit, for example via the temperature in the warm fresh water tank or in the wastewater tank, via the fill level in the warm fresh water tank or in the wastewater tank, or via the current demand for warm fresh water of the individual laundry treatment machines.The control unit is therefore advantageously also coupled to the laundry treatment machines. Furthermore, the control unit can determine the temperature of the fresh water in the fresh water line from the supplier as well as the flow rate to the heat exchanger using a flow meter. It is conceivable that the control unit could measure the inlet and outlet temperatures of the fresh water and wastewater in and out of the heat exchanger as an additional input variable, which could be used to control the valve arrangements and pumps.

[0020] The invention further relates to methods for operating a laundry system for the energy-reduced treatment of laundry, comprising a plurality of laundry treatment machines to which fresh water is supplied and by which wastewater is generated, and wherein the method comprises at least the following further steps: setting up a central fresh water warm tank in which warm fresh water is stored to supply the plurality of laundry treatment machines; setting up a central wastewater collection tank in which warm wastewater from the plurality of laundry treatment machines is stored and setting up a central heat exchanger through which the warm wastewater and fresh water flow, so that heat can be transferred from the wastewater to the fresh water.

[0021] In particular, a central fresh water line is provided, from which fresh water is supplied to the heat exchanger, and a line connection is also provided from the fresh water line into the fresh water warm tank, via which fresh water can be fed directly into the fresh water warm tank.

[0022] Furthermore, it is particularly advantageous to install a condensation heat exchanger into which exhaust air from the multiple laundry treatment machines is fed, and in which heat from the exhaust air is transferred to the fresh water already heated in the heat exchanger for further heating. The condensation heat exchanger is located, in particular, in a fresh water warm line that extends between the heat exchanger and the fresh water warm tank. It is also conceivable that the exhaust air is fed either completely, partially, or not at all to the condensation heat exchanger, depending on the pre-temperature of the heated fresh water that leaves the heat exchanger and is fed into the condensation heat exchanger via the fresh water warm line.The use of waste heat from the wastewater and / or from the exhaust air may depend on the current operating conditions of the laundry treatment machines, for example whether they are only just being put back into operation after a downtime period or which of the several laundry treatment machines are currently in operation.

[0023] The method advantageously further provides that a first valve arrangement is set up in the fresh water line, via which fresh water is fed into the fresh water warm tank via the line connection from the fresh water line. In addition, a second valve arrangement can be set up in the fresh water warm line, via which cold fresh water from the fresh water line is mixed with the fresh water heated by the condensation heat exchanger before this is transferred to the fresh water warm tank. According to the invention, a central control unit is set up to control the first valve arrangement in the fresh water line and / or the second valve arrangement in the fresh water warm line, wherein the control unit controls at least one valve arrangement based at least on the temperature of the fresh water in the fresh water warm tank and / or on the temperature in the wastewater collection tank. PREFERRED EMBODIMENT OF THE INVENTION

[0024] Further measures improving the invention are described in more detail below, together with the description of a preferred embodiment of the invention, with reference to the figures. It shows: Figure 1 shows a first embodiment of the laundry system with a heat exchanger for heating the fresh water using the warm wastewater; Figure 2 shows an embodiment of the laundry system with the first heat exchanger and with a condensation heat exchanger for absorbing heat from the exhaust air of the laundry treatment machines to heat the fresh water; Figure 3 shows the embodiment of the laundry system according to Figure 2 , whereby the heated water can be mixed with cold water via a fresh water pipe and Figure 4 shows a view of the arrangement of the heat exchanger in connection with the fresh water tank or alternatively with the waste water collection tank.

[0025] The Figure 1 , 2 and 3 show various exemplary embodiments of laundry systems 100 according to the present invention, each of which builds on the other in its variants. The common features of the exemplary embodiments will first be described below.

[0026] The laundry system 100 comprises a plurality of laundry treatment machines 10, 11, 12, which may, for example, be finishers, dryers, mangles, or the like. The laundry treatment machines 10, 11, 12 may further comprise intermittent washing machines or so-called continuous washing machines. Such laundry treatment machines 10, 11, 12 require heated fresh water 13 for their operation and themselves generate heated wastewater 14. The fresh water 13 is generally obtained from municipal suppliers. However, it is also conceivable that, depending on the process step for operating the laundry treatment machines 10, 11, 12, treated wastewater 14 forms the fresh water 13 or is mixed with it. The wastewater 14 usually has a higher temperature than the required temperature of the heated fresh water 13.

[0027] The embodiments of the laundry system 100 schematically show a discharge of the wastewater 14 from the laundry treatment machines 10, 11, 12, which is first fed to a wastewater buffer tank 28 and then, via a pump 29, through a return line 38 into a wastewater collection tank 16, where the warm wastewater 14 is stored.

[0028] The laundry system 100 is connected to a utility network via a fresh water line 18, so that the laundry system 100 can draw the fresh water 13 via the fresh water line 18. The fresh water 13 has a temperature of 12°C, for example, and first passes through a first valve arrangement 20 into a heat exchanger 17, before flowing via a fresh water warm line 27 into a fresh water warm tank 15. In the heat exchanger 17, the fresh water 13 is heated, for example, to a temperature of 50°C, which can also be 10°C higher or lower, preferably 5°C higher or lower. The heating of the cold fresh water 13 depends in particular on the temperature of the wastewater 14 from the wastewater collection tank 16, whereby the flow rate of the wastewater 14 also plays a role; the flow rate at which the fresh water 13 flows through the heat exchanger 17 is also crucial.

[0029] In order to bring the temperature of the fresh water 13 within the fresh water warm tank 15 to the desired level, for example to 55°C, a control unit 24 is provided, which is Figure 3 graphically shown, and in the embodiment of the laundry system 100 according to Figure 1 and according to Figure 2 is set up in the same way, but has not been graphically represented.

[0030] The control unit 24 records various measured variables in the laundry system 100 and is configured to control specific switching elements or active elements in the laundry system 100. Thus, the first valve arrangement 20, designed, for example, as a flow control valve, is located in the fresh water line 18 and can be controlled by the control unit 24. The valve arrangement 20 thus enables control of the amount of fresh water 13 that flows into the heat exchanger 17 and, thus, also into the fresh water warm tank 15. The amount of fresh water 13 flowing through the fresh water line 18 can be determined by means of a flow meter 35, which provides a measured value that is also recorded by the control unit 24 in a manner not shown in detail. The first valve arrangement 20 can thus be controlled by the control unit 24 in order to pass an adjusted amount of fresh water 13 through the heat exchanger 17 at a time.The flow rate through the heat exchanger 17 with the fresh water 13 can, for example, already be determined on the basis of the temperature which is measured by a temperature measuring device 25 in the fresh water warm tank 15, wherein the flow rate can also be determined via a fill level meter 32 with which the fill level of the fresh water 13 in the fresh water warm tank 15 is determined.

[0031] The flow of fresh water 13 through the first valve arrangement 20, the heat exchanger 17, and finally into the fresh water warm tank 15 can be controlled using the supplier-side system pressure in the fresh water line 18. Here, the control unit 24 can be controlled solely via a throttling effect or an intermittent release of the flow of fresh water 13 through the fresh water line 18 by means of the control unit 24, in which the control unit 24 controls the first valve arrangement 20 accordingly. Likewise, the flow through the line connection 19 can be controlled by the control unit 24 via the first valve arrangement 20, provided that a direct transfer of the fresh water 13 from the fresh water line 18 into the fresh water warm tank 15 is required, at least temporarily. Optionally, a throttle 39 is also shown in the line connection 19, which can also be controlled by the control unit 24.

[0032] As an alternative to controlling the first valve arrangement 20 by the control unit 24, it is also conceivable for the first valve arrangement 20 to be manually operated, in particular if, for example, the line connection 19 must be used briefly to supply the fresh water 13 to the fresh water warm tank 15. If the use of the heat in the wastewater 14 is not possible, for example, if the heat exchanger 17 is not ready for use, cold fresh water 13 can also flow from the fresh water line 18 into the fresh water warm tank 15 and be heated directly in the fresh water warm tank 15 by means of an electric heating unit 40. However, this option should only be used in emergency operation.

[0033] The fresh water 13 available in the fresh water warm tank 15 can be fed to the laundry treatment machines 10, 11, 12 via the pump 31 in a supply line 37. The wastewater 14 generated by the laundry treatment machines 10, 11, 12, however, is first collected in the wastewater buffer tank 28 and then fed to the wastewater collection tank 16 by the pump 29 via a return line 38. Both pumps 29 and 31 can be controlled via the control unit 24. The wastewater collection tank 16 also has a fill level gauge 33, and the transfer of the wastewater 14 from the wastewater buffer tank 28 to the wastewater collection tank 16 can be regulated by the control unit 24. The fill level in the wastewater collection tank 16 is measured using the fill level gauge 33 and recorded by the control unit 24, so that the pump 29 can be controlled accordingly.In a manner not shown in detail, it is also possible to determine the temperature of the wastewater 14 in the wastewater collection tank 16 using a further temperature measuring device and to feed this temperature value to the control unit 24.

[0034] The wastewater 14 at an elevated temperature can be fed from the wastewater collection tank 16 to the heat exchanger 17 by means of a pump 30. The supply quantity to the heat exchanger 17 can be controlled by speed control of the pump 30, in particular by means of the control unit 24, wherein the speed control is configured such that the quantity of warm wastewater 14 flows through the heat exchanger 17 that is necessary to bring the fresh water 13 to the desired temperature, so that the fresh water 13 at the desired temperature is finally transferred to the fresh water warm tank 15 via the fresh water warm line 27.

[0035] Controlling the pump 30 via its speed is particularly advantageous when the available quantity of wastewater 14 fluctuates coupled with a varying temperature of the wastewater 14. For example, colder wastewater 14 can flow through the heat exchanger 17 at a higher flow rate than warmer wastewater 14, whereby the total volume of the wastewater collection tank 16 should be fully utilized and larger level differences should occur. In other words, the speed control of the pump 30 should keep the transfer of thermal energy from the wastewater 14 to the fresh water 13 as constant as possible.However, it can also be provided, as a further control component, with the first valve arrangement 20 to regulate the fresh water quantity in such a way that, above all, a larger available quantity of thermal energy from the waste water 14 (for example, a large quantity of waste water with a high temperature) can also be used to heat a large quantity of fresh water 13, so that the fresh water tank 15 is filled especially for this situation.

[0036] This ensures that the correct amount of fresh water 13 is always present in the fresh water warm tank 15 and is supplied to the laundry treatment machines 10, 11, 12 via the supply line 37 by the pump 31 as required. The laundry treatment machines 10, 11, 12 are switched on and off intermittently during operation of the laundry system 100, and the machines 10, 11, 12 therefore only require a certain amount of fresh water 13 intermittently, and the machines 10, 11, 12 also only intermittently produce certain amounts of wastewater 14. With the aid of the control unit 24 for controlling the pumps 29, 30, 31 and using the wastewater buffer tank 28, it can be ensured that the fresh water 13 is always available in the desired amount in the fresh water warm tank 15, and it can be ensured that sufficient wastewater 14 is always stored at a desired temperature in the wastewater collection tank 16.Once the wastewater 14 has passed through the heat exchanger 17, it can finally be discharged via the wastewater channel 34.

[0037] Beyond the basic structure of the illustrated embodiments of the laundry systems 100, Figure 2the use of a further heat exchanger in the form of a condensation heat exchanger 21 in the fresh water warm line 27. The condensation heat exchanger 21 is designed so that the exhaust air 22 of the laundry treatment machines 10, 11, 12 is fed into the condensation heat exchanger 21 and there the moisture of the exhaust air 22 is extracted from it while simultaneously cooling it, whereby the exhaust air 22 is dried, so that the energy released in this way is transferred to the fresh water 13, which finally, further heated, reaches the fresh water warm tank 15 via the fresh water warm line 27. Thus, the fresh water 13 can undergo a first heating stage via the heat exchanger 17, in which heat is extracted from the waste water 14 of the machines 10, 11, 12, and in a second heating step, the already preheated fresh water 13 can be further heated in the condensation heat exchanger 21 via the exhaust air 22 of the laundry treatment machines 10, 11, 12.The temperature of the moist exhaust air 22 of the laundry treatment machines 10, 11, 12 is usually higher than the temperature of the waste water 14. Therefore, a first heating stage by means of the waste water 14 and a second heating stage by means of the exhaust air 22 is possible.

[0038] In yet another embodiment according to Figure 3A further second valve arrangement 23 is installed in the fresh water warm line 27 downstream of the condensation heat exchanger 21. Cold fresh water 13 from the fresh water warm line 18' can be added to the heated fresh water 13 leaving the condensation heat exchanger 21 via the second valve arrangement 23 in order to set the desired temperature in the fresh water 13, which ultimately flows into the fresh water warm tank 15. For this purpose, the control unit 24 can also control the second valve arrangement 23. A temperature measuring device 26 can measure the temperature of the fresh water in the rear fresh water warm line 27 downstream of the second valve arrangement 23, and the temperature can be adjusted so that the desired temperature in the fresh water warm tank 15 is ultimately reached, which temperature is monitored by the temperature measuring device 25 using the control unit 24.

[0039] Figure 4shows one possible arrangement of the heat exchanger 17 around the fresh water warm tank 15. Similarly, alternatively or additionally, a heat exchanger 17 can also be arranged around the wastewater collection tank 16. The example shows the fresh water warm tank 15, which is fed with the heated fresh water 13 via the fresh water warm line 27 and can be emptied by means of the pump 31 via the supply line 37, which transfers the heated fresh water 13 at the required temperature to the laundry treatment machines, which are not shown in detail here.

[0040] The heat exchanger 17 is designed as a counterflow heat exchanger and has a coaxial pipe system 36 comprising an inner pipe 36a and an outer pipe 36b. The inner pipe 36a runs within the larger outer pipe 36b, with the flow directions of the inner pipe 36a and the outer pipe 36b being opposite. This design of a heat exchanger 17 as a coaxial pipe heat exchanger offers the possibility of a space-saving arrangement around at least one of the tanks 15, 16, and the heat exchanger 17 can, for example, have a height of 3 m and a diameter of 1.8 m. Of course, the helical shape of the coaxial pipe system 36 can be adapted to the outer diameter of the tank 15, 16.Depending on the necessary flow length of the fresh water 13 or waste water 14 for sufficient heat exchange, a corresponding heat exchanger with a coaxial pipe system 36 can also be formed around both tanks 15, 16, through which the flow can be parallel or successively.

[0041] The invention is not limited in its implementation to the preferred embodiment described above. Rather, a number of variants are conceivable, which utilize the presented solution even in fundamentally different embodiments. All features and / or advantages apparent from the claims, the description, or the drawings, including structural details or spatial arrangements, may be essential to the invention both individually and in a wide variety of combinations. List of reference symbols:

[0042] 10 Laundry treatment machine 11 Laundry treatment machine 12 Laundry treatment machine 13 Fresh water 14 Waste water 15 Fresh water warm tank 16 Waste water collection tank 17 Heat exchanger 18 Fresh water line 18 Fresh water line 19 Pipe connection 20 First valve arrangement 21 Condensation heat exchanger 22 Exhaust air 23 Second valve arrangement 24 Control unit 25 Temperature measuring device 26 Temperature measuring device 27 Fresh water warm line 28 Waste water buffer tank 29 Pump 30 Pump 31 Pump 32 Level gauge 33 Level gauge 34 Waste water channel 35 Flow meter 36 Coaxial pipe system 36a Inner pipe 36b Outer pipe 37 Supply line 38 Return line 39 Throttle 40 Electric heating unit 100Laundry system

Claims

1. Laundry system (100) for the energy-reduced treatment of laundry, comprising a plurality of laundry treatment machines (10, 11, 12) to which fresh water (13) is supplied and which produce waste water (14), characterized in that - a central fresh water warm tank (15) is set up, in which warm fresh water (13) can be stored to supply the plurality of laundry treatment machines (10, 11, 12), - a central waste water collection tank (16) is set up, in which warm waste water (14) from the plurality of laundry treatment machines (10, 11, 12) can be stored, - a central heat exchanger (17) is set up, through which the warm waste water (14) and fresh water (13) can flow, so that heat can be transferred from the waste water (14) to the fresh water (13).

2. Laundry system (100) according to claim 1, characterized by that the heat exchanger (17) is formed by means of a coaxial tube heat exchanger.

3. Laundry system (100) according to claim 1 or 2, characterized by that the heat exchanger (17) is arranged helically around the fresh water warm tank (15) and / or around the waste water collection tank (16).

4. Laundry system (100) according to one of claims 1 to 3, characterized by that the heat exchanger (17) is designed and / or connected in such a way that the fresh water (13) and the waste water (14) can flow through it in countercurrent.

5. Laundry system (100) according to one of the preceding claims, characterized by that a fresh water line (18) is provided, from which fresh water (13) can be supplied to the heat exchanger (17), wherein furthermore a line connection (19) from the fresh water line (18) into the fresh water warm tank (15) is provided, in particular so that the laundry system is designed free of a fresh water cold tank.

6. Laundry system (100) according to one of the preceding claims, characterized by thata first valve arrangement (20) is arranged in the fresh water line (18), to which the line connection (19) from the fresh water line (18) into the fresh water warm tank (15) is connected.

7. Laundry system (100) according to one of the preceding claims, characterized by that a fresh water warm line (27) is arranged between the heat exchanger (17) and the fresh water warm tank (15), in which a condensation heat exchanger (21) is arranged, wherein exhaust air (22) from the plurality of laundry treatment machines (10, 11, 12) can be introduced into the condensation heat exchanger (21) and heat of the exhaust air (22) can be transferred to the fresh water (13) already heated in the heat exchanger (17) for further heating.

8. Laundry system (100) according to claim 7, characterized by thata second valve arrangement (23) is arranged in the fresh water warm line (27), via which cold fresh water (13) from the fresh water line (18') can be mixed with the fresh water (13) heated by the condensation heat exchanger (21) before this can be transferred into the fresh water warm tank (15).

9. Laundry system (100) according to one of the preceding claims, characterized by that a control unit (24) is arranged which is arranged at least for controlling and / or regulating the first valve arrangement (20) and / or for controlling and / or regulating the second valve arrangement (23).

10. Laundry system (100) according to claim 9, characterized by thatthe fresh water warm tank (15) has a temperature measuring device (25) which is designed to output a temperature measured value to the control unit (24) and / or that a temperature measuring device (26) is arranged in the fresh water line (18) leading into the fresh water warm tank (15), which is designed to output a temperature measured value to the control unit (24).

11. Laundry system (100) according to claim 9 or 10, characterized by thatthe control unit (24) is configured to control a first pump (29) for conveying a specific volume flow from a waste water buffer tank (28) into the waste water tank (16) and / or to control a second pump (30) for conveying a specific volume flow from the waste water tank (16) into the heat exchanger (17) and / or to control a third pump (31) for conveying a specific volume flow of warm fresh water (13) from the fresh water warm tank (15) to the plurality of laundry treatment machines (10, 11, 12).

12. A method for operating a laundry system (100) for the energy-reduced treatment of laundry, comprising a plurality of laundry treatment machines (10, 11, 12) to which fresh water (13) is supplied and by which wastewater (14) is generated, and wherein the method comprises at least the following further steps: - setting up a central fresh water warm tank (15) in which warm fresh water (13) is stored to supply the plurality of laundry treatment machines (10, 11, 12); - setting up a central wastewater collection tank (16) in which warm wastewater (14) from the plurality of laundry treatment machines (10, 11, 12) is stored, - setting up a central heat exchanger (17) through which the warm wastewater (14) and fresh water (13) flow, so that heat is transferred from the wastewater (14) to the fresh water (13).

13. Method according to claim 12, characterized by thata central fresh water line (18) is set up, from which fresh water (13) is supplied to the heat exchanger (17), wherein furthermore a line connection (19) from the fresh water line (18) into the fresh water warm tank (15) is set up, via which fresh water (13) is led directly into the fresh water warm tank (15).

14. Method according to claim 12 or 13, characterized by that a condensation heat exchanger (21) is provided, into which exhaust air (22) from the plurality of laundry treatment machines (10, 11, 12) is introduced and in which heat of the exhaust air (22) is transferred to the fresh water (13) already heated in the heat exchanger (17) for further heating.

15. Method according to one of claims 12 to 14, characterized by that- a first valve arrangement (20) is arranged in the fresh water line (18), via which fresh water (13) is led from the fresh water line (18) into the fresh water warm tank (15) by means of the line connection (19), and / or - a second valve arrangement (23) is arranged in the fresh water warm line (27), via which cold fresh water (13) from the fresh water line (18) is mixed with the fresh water (13) heated by the condensation heat exchanger (21) before said fresh water is transferred to the fresh water warm tank (15), wherein - a central control unit (24) is arranged to control the first valve arrangement (20) in the fresh water line (18) and / or the second valve arrangement (23) in the fresh water warm line (27), wherein the control unit (24) controls at least one valve arrangement (20,23) is carried out at least based on the temperature of the fresh water (13) in the fresh water warm tank (15) and / or based on the temperature in the waste water collection tank (16).

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