DE102019218097A1 - Energy recovery exchanger - Google Patents

Abstract

The proposal is for a domestic dishwasher with a receiving space (1) for receiving items to be washed (2), and with a water supply line (4) for supplying the domestic dishwasher with water from a water supply connection (3) connected to the water supply line (4) when the domestic dishwasher is in operation. The domestic dishwasher is characterized in that it has at least one tank arrangement (5), the tank arrangement (5) having a supply water space (6) for receiving supply water from the supply water line (4) and a waste water space (7) for receiving waste water from the Receiving space (1), the supply water space (6) and the waste water space (7) being in heat-conducting connection in order to enable heat transfer from the waste water in the waste water space (7) to the supply water in the supply water space (6). A method for operating a household dishwasher is also described.

Description

The present invention relates to a domestic dishwasher with a receiving space for receiving items to be washed and with a supply water line for supplying the domestic dishwasher with supply water from a supply water connection connected to the supply water line when the domestic dishwasher is in operation.

Furthermore, a method for operating a domestic dishwasher with a receiving space for receiving items to be washed and with a supply water line via which the domestic dishwasher is supplied with supply water from a supply water connection connected to the supply water line is described.

Household dishwashers are known in the prior art and are used in principle to clean and then dry soiled items to be washed, for example dishes or cutlery. During one or more cleaning steps of a wash cycle (beginning with a pre-wash or cleaning step and ending with a drying step), water (possibly mixed with detergent or rinse aid) is applied to the wash ware in order to loosen soiling from the wash ware. To dry the items to be washed, household dishwashers have a drying system for the cleaned items, with the aid of which air absorbs the water that adheres to the cleaned and warm items in the form of steam and thereby dries the items.

In general, when operating household dishwashers, it is necessary to heat supply water that comes from a supply water connection connected to the household dishwasher before it is fed into the receiving space and there comes into contact with the items to be washed in order to effect the desired cleaning of the items to be washed. For this purpose, it is known to equip the household dishwasher with a heat pump or to provide an electrical heating device with the help of which the supply water is heated in a supply water tank provided for this purpose or while it is passing through a supply water line present within the household dishwasher.

The object of the present invention is to reduce the energy consumption of a corresponding household dishwasher.

The object is achieved by a household dishwasher and a method for operating such with the features of the independent claims.

According to the invention, the household dishwasher has a receiving space for receiving items to be washed. Inside the receiving space there are one or more crockery baskets and spray water devices with which the items to be washed can be sprayed with washing liquor (= supply water coming from a supply water line or supply water with detergent and / or rinse aid). The household dishwasher also includes a water supply line, via which it is connected to a supply water connection such as a building, a collecting tank, a pump storage tank, etc ... which is used to supply the household dishwasher with supply water.

In particular, the supply water can be fresh water. This is preferably provided via the domestic water installation of a building by means of a corresponding supply line of the domestic dishwasher. The domestic water installation is preferably connected to the water supply network of a water supplier, e.g. in Germany the municipal utilities of a city or municipality. In the context of the invention, the supply water is also referred to as supply medium, feed water, process medium or filling medium.

According to the invention it is now provided that the household dishwasher has at least one tank arrangement, the tank arrangement having a supply water space for receiving supply water from the supply water line and a waste water space for receiving waste water from the receiving space, the supply water space and the waste water space being in heat-conducting connection around a To enable heat transfer from the wastewater in the wastewater room to the supply water in the supply water room.

In the case of the household dishwasher according to the invention, the supply water is therefore not fed directly from the supply water connection via the supply water line into the receiving space. Rather, the supply water first reaches the supply water space of the tank arrangement and is temporarily stored here before it is introduced into the receiving space. During the intermediate storage, heat can be transferred from the wastewater to the supply water, so that the thermal energy present in the wastewater can be used to preheat the supply water.

The wastewater is water that was previously brought into contact with the items to be washed in the receiving space. In addition to contamination from the items to be washed, the wastewater can also contain cleaning agents and / or rinsing agents. In any case, the wastewater has a certain thermal energy if it was previously heated during a cleaning step or a final rinse step inside the domestic dishwasher. In the case of the domestic dishwasher according to the invention, this thermal energy stored in the wastewater is not passed directly with the wastewater into a wastewater pipe of the domestic dishwasher, via which the wastewater finally leaves the domestic dishwasher. Rather, an at least partial transfer of the thermal energy from the wastewater to the supply water takes place beforehand. As a result, the total heat requirement of the household dishwasher during a wash cycle can be significantly reduced compared to the prior art.

The tank arrangement is preferably a container made of metal or plastic, which can include both the supply water space (= cavity, which serves to temporarily hold supply water) and the waste water space (= cavity, which is used to temporarily hold waste water). It is also conceivable that the tank arrangement has two separate containers, one container comprising the supply water space and the second container comprising the waste water space. Finally, it is also possible that the tank arrangement comprises more than two cavities, so that, for example, the supply water space and / or the waste water space has several individual interconnected cavities, the cavities for the supply water being the supply water space and / or the cavities for the waste water being the waste water space form.

In particular, it is advantageous if the supply water space is arranged at least in sections, preferably completely, between the receiving space and the waste water space. If cold supply water, in particular cold fresh water, is now fed from a supply water line into the supply water space, at least some of the walls of the tank arrangement that delimit the supply water space initially cool down. If the supply water space is now filled with cold supply water from the supply water line during a drying step, heat can be transferred from the receiving space to the supply water in the supply water space. As a result, on the one hand, the supply water is preheated, which reaches the receiving space in a subsequent wash cycle. On the other hand, the cold supply water in the supply water space can cool the moist air circulating or present therein due to the proximity to the receiving space. This promotes condensation of the water vapor present in the receiving space, so that the drying of the air mentioned and thus also of the items to be washed can be accelerated.

There are also advantages if the domestic dishwasher has an outer wall that closes off the domestic dishwasher towards the outside, the waste water space being arranged between the outer wall and the supply water space. In this case, the supply water space is spaced apart from the surroundings of the domestic dishwasher by the waste water space. This has the advantage that the cold supply water present in the supply water space does not lead to a cooling of the outer wall. In this way, condensation of air humidity from the air surrounding the household dishwasher on the outer wall can be avoided. At the same time, this leads to a reduction in the risk of mold formation or mold stains or even drops of condensation water on the outer wall of the domestic dishwasher.

It is also advantageous if the tank arrangement has at least one partition, a first side of the partition delimiting the waste water space and a second side of the partition delimiting the supply water space in sections. The tank arrangement is therefore preferably a single container which is delimited by a common outer wall. Finally, the named partition is present inside the container, which divides the container into two parts, one part forming the supply water space and the second part forming the waste water space. The partition is preferably at least partially, in particular completely, in a vertical plane, in particular when the tank arrangement is attached to the outside of a vertical side wall or the rear wall of the washing compartment. Additionally or independently of this, the tank arrangement can be provided on the outside on the top wall or below the bottom wall of the washing compartment. In this possible configuration, too, the wastewater space is expediently further outside than the supply water space with respect to the respective wall of the washing container assigned to the tank arrangement. Both the supply water space and the waste water space are preferably located in a horizontal plane and are in particular separated from one another by a horizontal or horizontally extending partition wall.

It is also advantageous if the household dishwasher has two tank arrangements having, wherein a first tank arrangement is arranged in the region of a first side wall of the domestic dishwasher and the second tank arrangement is arranged in the region of a second side wall of the domestic dishwasher. Each of the tank arrangements preferably has its own waste water space and its own supply water space. The individual wastewater spaces and the individual supply water spaces can each be connected to one another. In this way, it is possible to isolate both side walls of the domestic dishwasher, each with a waste water space, to the outside, with a supply water space being located between the receiving space and an adjacent waste water space. The respective supply water spaces are thus separated from the surroundings of the domestic dishwasher by the respective waste water spaces.

It is also advantageous if the household dishwasher comprises a heat pump arrangement through which a heat transfer medium flows during its operation, the heat pump arrangement including, among other things, an evaporator which is arranged at least in sections within the supply water space or is in heat-conducting connection with it, and with it Help heat from the supply water can be transferred to the heat carrier.

The heat pump arrangement includes, inter alia, a heat exchanger which forms the said evaporator and is used to evaporate a heat carrier flowing through the heat exchanger. The heat required for evaporation in the evaporator comes at least partially from the supply water present in the supply water space. For example, the evaporator comprises one or more evaporator tubes or evaporator plates, which extend into the supply water space or are in heat-conducting connection with one or more walls of the tank arrangement that delimit the supply water space.

If a heat transfer medium now flows through the evaporator, it absorbs heat from the supply water via the wall of the evaporator tubes or evaporator plates, which cools down and possibly even partially freezes. In general, the evaporator can also serve to cool one or more walls during a drying step of the wash cycle in order to bring about condensation of water vapor within the receiving space.

The heat transfer medium leaving the evaporator flows on to the compressor (other name: compressor). With the aid of the compressor, the gaseous heat transfer medium entering the compressor during operation of the heat pump arrangement is compressed, whereby it heats up.

Furthermore, the heat pump arrangement comprises a heat exchanger acting as a condenser (other name: condenser), in which the heated gaseous heat carrier that passes through the heat exchanger from the compressor condenses again and in the process gives off heat that is intended for the heating of the space provided for entry into the receiving space Supply water and / or sewage can be used.

The liquefied heat transfer medium is then expanded with the help of an expansion arrangement (e.g. one or more capillary tubes or a controllable expansion valve) and finally returns to the evaporator, where it returns to the gaseous state with renewed heat absorption and then fed back to the compressor so that the heat transfer circuit closes.

The heat exchangers mentioned can be present, for example, as a pipe coil or also as heat exchangers of flat design (so-called plate heat exchangers). In each case, there is at least one inlet and one outlet for the heat transfer medium, so that the heat transfer medium can pass through the heat pump arrangement without coming into direct contact with the supply water in the supply water space.

It is also extremely advantageous if the waste water space is connected to a waste water line which connects the waste water space with the receiving space. This makes it possible for waste water, which has preferably given off heat to the supply water in the adjacent supply water space, to be conducted again into the receiving space. The wastewater can thus be brought into contact with the items to be washed again before it is finally passed through a wastewater connection from the domestic dishwasher and into a wastewater network. Whether the wastewater is re-used as a process medium, especially in the receiving room or wash room, preferably runs through a new wash cycle (such as one or more liquid-carrying partial wash cycles of a wash cycle), can expediently be determined based on its degree of soiling using a dirt sensor such as a so-called aqua sensor . For example, it would also be conceivable to equip the sewage line with a pump, in particular a circulation pump, via which the sewage is circulated at least temporarily between the sewage space and the receiving space during a wash cycle.

It is advantageous if the wastewater space is also connected to a wastewater connection of the domestic dishwasher via the wastewater pipe, via which wastewater can be discharged from the domestic dishwasher when the domestic dishwasher is in operation. In particular, it is therefore advantageous if the household dishwasher has a waste water line via which the waste water space, the receiving space and also the waste water connection are connected to one another. The wastewater line can have one or more valves, via which it can be determined whether the wastewater flows from the wastewater space into the receiving space or to the wastewater connection. For example, it would be conceivable that the sewer line has a section that runs from the sewer space to the sewer connection, a further section of the sewer line branching off from this section, which in turn opens into the receiving space, for example in the area of a pump sump of the domestic dishwasher.

In general, it is also conceivable that the waste water space is formed by a section of the waste water pipe. For example, the sewer pipe or part of it could be designed as a sewer hose or sewer pipe, the sewer pipe or sewer hose running in a meandering shape and, for example, being directly adjacent to a wall that delimits the supply water space. This ensures good heat transfer from the waste water within the waste water pipe or the waste water hose to the supply water in the supply water space.

In addition, it can be advantageous if the waste water space is delimited to the outside by one or more delimiting surfaces, the delimiting surface (s) having or have a lotus effect at least in sections on the side facing the waste water space. This prevents or makes it more difficult for contaminants that may be present in the wastewater to adhere.

The invention also relates to a method for operating a household dishwasher with a receiving space for accommodating items to be washed, and with a supply water connection via which the household dishwasher is supplied with supply water during its operation from a supply water line connected to the supply water connection.

With regard to possible physical features of the household dishwasher, reference is made to the previous or following description. The individual features can be implemented individually or in any combination, provided that this is technically possible and sensible.

In any case, it is provided that the domestic dishwasher has at least one tank arrangement, the tank arrangement having a supply water space for receiving supply water from the supply water line and a waste water space for receiving waste water from the receiving space. It is also part of the invention that, during a wash cycle, heat is transferred at least temporarily from the waste water in the waste water space to the supply water in the supply water space. Before wastewater, which was previously used to clean dishes in the receiving area, is removed from the domestic dishwasher via a wastewater connection, part of the thermal energy present in the wastewater is transferred to supply water, which has flowed from a supply water pipe into the supply water chamber of the household dishwasher.

In particular, it is conceivable that before the start of a wash cycle, heat is transferred from the wastewater in the wastewater room to supply water in the supply water room, the wastewater in the wastewater room originating from a previous wash cycle and the supply water coming from a supply water line connected to the domestic dishwasher. During a pre-wash step, during which the items to be washed are sprayed with water within the receiving space in order to remove coarse soiling from the items to be washed, it is advantageous if some of the supply water is brought from the supply water space into the receiving space. At the same time, it is advantageous if wastewater is removed from the wastewater chamber of the household dishwasher during the pre-wash step. During the pre-wash step, all of the wastewater present in the wastewater space is preferably discharged from the domestic dishwasher via a wastewater connection.

A cleaning step usually follows the pre-wash step. It is advantageous here if the waste water space is filled again with waste water which originates from the receiving space and which was previously applied to the items to be washed in the pre-wash step. It is also advantageous during the cleaning step if the supply water space is also filled again with supply water, so that heat can be transferred from the waste water to the supply water introduced into the supply water space.

The cleaning step is preferably followed by an intermediate rinsing step, during which the items to be washed are removed from the receiving space with water Supply water space is splashed. Likewise, during the intermediate rinsing step, waste water should be passed from the receiving space into the waste water space. Towards the end of the intermediate rinsing step, supply water is again fed into the supply water space, which absorbs heat from the waste water that is now in the waste water space.

In the subsequent final rinse step, during which the items to be washed are sprayed with supply water from the supply water tank, which is mixed with a clear rinse aid, the waste water space is finally emptied by draining waste water from the waste water space via the waste water connection from the domestic dishwasher. Towards the end of the final rinse step, both the supply water space and the waste water space are at least largely emptied.

Finally, a drying step of the washing cycle is carried out, during which any waste water still present in the receiving space is discharged into the waste water space or from the domestic dishwasher. At the same time, the supply water space is filled with supply water, so that the heat from the waste water in the waste water space can be transferred to the new supply water introduced into the supply water space. The supply water is thus warmed up and is available in a warmed-up state for a subsequent wash cycle.

It has particular advantages if the supply water present in the supply water space is at least partially released into the receiving space after heat has passed from the waste water to the supply water. Of course, it is also possible, during selected sections of a wash cycle, to pass supply water, which flows into the domestic dishwasher via the supply water connection, via the supply water space into the receiving space without dwell time. In principle, however, the rinse cycle should include one or more time periods during which supply water is temporarily stored in the supply water space and waste water is temporarily stored in the waste water space, so that the desired heat transfer from the waste water to the supply water is enabled.

It is also advantageous if the supply water present in the supply water space is at least partially released into the receiving space after between 40% and 70% of the latent amount of heat in the waste water has been transferred to the supply water. While a value of less than 40% means a relatively low heat transfer and thus a relatively low utilization of the amount of heat available in the wastewater, a value of over 70% would result in too long a residence time of the supply water in the supply water space or of the wastewater in the wastewater space. This in turn would lead to an excessively or disproportionately long duration of the wash cycle. A value in the range mentioned thus enables a significant saving of energy, the duration of the wash cycle not having to be excessively lengthened compared to a wash cycle known from the prior art.

It has particular advantages if the wastewater present in the wastewater space is at least partially discharged from the domestic dishwasher and / or released into the receiving space after heat has passed from the wastewater to the supply water. After the desired heat transfer from the wastewater to the supply water, the wastewater can thus be discharged from the domestic dishwasher or fed back into the receiving space in order to be sprayed onto the items to be washed again in a further step of the washing program. It is also possible at the same time to conduct part of the waste water present in the waste water space into the receiving space, while a further part of the waste water present in the waste water space is removed from the domestic dishwasher.

There are also advantages if wastewater from the wastewater space is discharged at least partially and / or temporarily directly and without passing through the receiving space or a pump sump belonging to the receiving space into the sewage pipe. It is therefore conceivable that wastewater from the wastewater space is first passed into the receiving space and from there removed from the domestic dishwasher. It is also possible for the wastewater to be conveyed via a wastewater pipe from the wastewater room directly in the direction of the wastewater connection, via which it is finally removed from the domestic dishwasher.

It has particular advantages if the household dishwasher comprises a heat pump arrangement through which a heat transfer medium flows during its operation, the heat pump arrangement including an evaporator which is at least partially arranged within the supply water space or is in heat-conducting connection with it, and with the help of which heat is at least temporarily transferred from the supply water to the heat transfer medium during a wash cycle. With regard to further details of the heat pump arrangement, reference is made to the description above or below.

If the heat pump arrangement is operated, heat is transferred from the supply water to the heat transfer medium in the supply water space transferred so that the supply water cools and it comes to an evaporation of the heat carrier in the evaporator at the same time. Since the supply water has previously absorbed heat in the wastewater space from the wastewater present there, a particularly large amount of heat is available, which in turn ensures a high efficiency of the heat pump arrangement. In particular, premature icing of the supply water in the supply water space is counteracted. As a result, the heat pump not only remains in a first heating phase, in particular the cleaning step, of a dishwashing program to be carried out, in which washing liquid mixed with detergent has to be heated to a required minimum temperature by means of the condenser or condenser of the heat pump arrangement in order to act on washware in the washing area of the washing container in a later, second heating phase, in particular the final rinse step of the dishwashing program, in which rinse aid mixed with rinse aid is heated to a specific minimum temperature in order to apply rinse aid in the washing compartment of the washing compartment, each with a high degree of efficiency. The washing liquid for the respective washing liquid-carrying partial washing step of the respective dishwashing program to be carried out is taken from the supply water chamber at the beginning of the respective washing-liquid carrying partial washing step and fed to the washing chamber of the washing container. The amount of supply water or amount of washing liquid removed from the supply water chamber for the respective partial washing step is expediently refilled into the supply water chamber via the supply water line from the supply water connection.

• 1 ausgewählte Abschnitte einer erfindungsgemäßen Geschirrspülmaschine,
• 2 Füllstände in der Tankanordnung einer erfindungsgemäßen Geschirrspülmaschine während eines Spülgangs,
• 3 eine zu 1 alternative Ausführung ausgewählter Abschnitte einer erfindungsgemäßen Geschirrspülmaschine,
• 4 eine zu 1 alternative weitere Ausführung ausgewählter Abschnitte einer erfindungsgemäßen Geschirrspülmaschine,
• 5 ausgewählte Abschnitte einer weiteren Ausführungsform einer erfindungsgemäßen Geschirrspülmaschine,
• 6 Füllstände in der Tankanordnung einer erfindungsgemäßen Geschirrspülmaschine gemäß 5 während eines Spülgangs, und
• 7 ausgewählte Abschnitte einer weiteren Ausführungsform einer erfindungsgemäßen Geschirrspülmaschine.

The invention and its advantageous designs and developments as well as their advantages are explained in more detail below with reference to drawings. It shows, each in a schematic sketch:

• 1 selected sections of a dishwasher according to the invention,
• 2 Fill levels in the tank arrangement of a dishwasher according to the invention during a wash cycle,
• 3rd one to 1 alternative embodiment of selected sections of a dishwasher according to the invention,
• 4th one to 1 alternative further embodiment of selected sections of a dishwasher according to the invention,
• 5 selected sections of a further embodiment of a dishwasher according to the invention,
• 6th Fill levels in the tank arrangement of a dishwasher according to the invention according to 5 during a wash cycle, and
• 7th selected sections of a further embodiment of a dishwasher according to the invention.

1 shows selected sections of a household dishwasher. Here, only those components of the household dishwasher are shown, provided with reference numerals and explained, which are necessary for understanding the invention. It goes without saying that the household dishwasher according to the invention can comprise further parts and assemblies.

The household dishwasher comprises a receiving space surrounded by walls 1 for holding items to be cleaned 2 , for example crockery or cutlery. In order to supply the household dishwasher with supply water, in particular fresh water, a supply water line consisting of several sections is required 4th , in particular fresh water pipe, provided. The supply water pipe 4th extends from a supply water connection 3rd , for example a faucet of a supply water, in particular fresh water supply, of a building in which the household dishwasher is installed, via a first valve 16a and a safety valve 21 to a three-way valve 20th . With regard to the valve 16a mentioned and the valves 16a to 16r mentioned below, it should be noted in general that these can be controlled by a control unit, not shown, of the domestic dishwasher.

With the help of the three-way valve, which is also connected to the control unit 20th it can be determined during a wash cycle whether the supply water is to be supplied via a softening device 19th the household dishwasher and the other valves 16c and 16d in the two tank arrangements described in more detail below 5 flows.

There is also a sewer pipe consisting of several sections 12th Part of the household dishwasher. The sewer pipe 12th ends with a sewer connection 13th , for example with a siphon 14th a sewage disposal line, not shown, of said building is connected.

There is also a sewage pump 15th provided, with the help of which the wastewater through the valve 16e from the recording room 1 , for example from a pump sump of the domestic dishwasher, can be pumped out. Likewise is the Sewer 12th via corresponding sections with the specified tank arrangements 5 in connection, so that, as described in more detail below, wastewater that is temporarily in the tank assemblies 5 is located via the sewage connection 13th can be removed from the household dishwasher.

Waste water in the context of the present invention is in principle a mixture of supply water which the domestic dishwasher is supplied via the supply water connection 3rd was made available before or during a wash cycle and any contamination from the wash ware 2 Were rinsed off and / or cleaning agent and / or rinse aid, which in the course of a wash cycle also in the receiving space 1 is delivered.

There is also a pump 18th provided on the sewage from the receiving room 1 via a check valve 17th and depending on the position of the valve 16b in the direction of the sewage connection 13th or in the two tank arrangements 5 can be pumped. The pump 18th can in particular be provided by a circulating pump which is preferably already present in the base support of the household dishwasher and which is preferably in fluid connection with a water switch. The latter then expediently has a corresponding outlet to the check valve 17th or corresponding outlets to the tank arrangements 5 as well as to the waste water connection 13th on. Alternatively, the pump 18th be provided in a corresponding manner by an existing in the domestic dishwasher drain pump. Of course the pump can 18th also be formed by an additionally provided pump or by some other liquid delivery device.

How 1 It can be seen that the household dishwasher comprises two tank arrangements 5 , each with a tank assembly 5 in the area of a side wall 10 the household dishwasher is arranged, which in turn is the receiving space 1 limited to the outside. In the example shown, the respective outer walls form the tank assemblies 5 an outer wall 8th the household dishwasher. It is of course also conceivable that there is another wall, not shown, which forms the outer surface of the domestic dishwasher and either directly on the named outer wall 8th is applied or is spaced apart from this by a further section, for example an insulation.

Regardless of the exact design of the household dishwasher, it should be pointed out at this point that, contrary to some of the figures, the sections shown are of course arranged in a housing which delimits the household dishwasher from the outside (the housing being partially defined by the outer walls of the tank arrangements mentioned in the previous paragraph 5 can be formed).

The individual tank arrangements 5 now each include a water supply room 6th for receiving via the supply water connection 3rd supplied supply water as well as a spatially from the supply water room 6th separate sewage room 7th . The separation can for example by a partition 9 respectively. It is also conceivable that the supply water space 6th and the sewer room 7th each formed by a separate container, the corresponding containers being in a thermally conductive connection.

1 also shows that the respective supply water spaces 6th via a corresponding section of the supply water pipe 4th with the supply water connection 3rd stay in contact. The supply water rooms 6th can therefore be filled with supply water when required and controlled by the said control unit. From the respective supply water room 6th finally leads to a supply water inlet 22nd in the recording room 1 so that in the supply water room 6th via the supply water pipe 4th inflowing supply water that is already in the supply water space 6th existing supply water in the receiving room 1 repressed.

The respective sewage rooms are analogous to this 7th via appropriate wastewater inlets 23 with the recording room 1 in connection, so that wastewater via the respective wastewater inlet 23 in the recording room 1 can flow if over each with the sewer space 7th connected sections of sewer 12th and with the help of the pump 18th Waste water in the appropriate waste water rooms 7th is pumped.

Sewage that is in the receiving room 1 is located, so can with the help of the pump 18th either directly in the direction of the sewage connection 13th or back to the sewage rooms 7th are pumped, so that this wastewater in the further course of a wash cycle again in the receiving space 1 arrives and there further contamination from the items to be washed 2 can accommodate.

The basic idea of the invention is that wastewater which was previously heated in the course of a wash cycle with the aid of an electrical heater (not shown) of the domestic dishwasher or with the heat pump arrangement described in more detail below, Can give off heat to the supply water, which is in the supply water rooms 6th is located.

2 now shows the level inside the sewage rooms 7th (V1) and the level within the supply water spaces 6th (V2) during a wash cycle which comprises a pre-wash step (I), a cleaning step (II), an intermediate wash step (III) and a final-rinse step (IV). This is followed by a drying step, which, however, takes place in 2 is not shown in detail.

Before the start of the wash cycle are the sewage rooms 7th with wastewater from a previous wash cycle and the supply water rooms 6th with supply water from the supply water connection 3rd filled. Heat from the wastewater can thus be transferred to the supply water.

At the beginning of the pre-wash step, the wastewater is removed from the wastewater rooms 7th in the siphon 14th emptied. At the same time, part of the supply water is in the receiving room 1 handed over to there with the items to be washed 2 to get in touch. Towards the end of the pre-wash step, the previously partially emptied supply water spaces are refilled 6th with supply water from the supply water connection 3rd . At the same time, wastewater is released from the receiving room 1 in the sewage rooms 7th pumped so that their level rises again.

After the pre-wash step, there is a cleaning step, during which waste water is removed from the waste water rooms 7th via the siphon 14th is disposed of. Likewise, supply water is fed into the supply water rooms 6th piped so that from there supply water to the receiving room 1 is displaced to there with the items to be washed 2 to come into contact for the purpose of cleaning it.

After the cleaning step, an intermediate washing step is carried out during which the items to be washed 2 within the recording room 1 of supply water from the supply water spaces 6th is acted upon to remove stubborn impurities from the items to be washed 2 to solve. The level of the supply water rooms 6th is reduced as a result. Likewise, wastewater is released from the receiving room 1 in the sewage rooms 7th pumped so that their level increases again. Towards the end of the intermediate rinsing step, the supply water spaces 6th again with supply water from the supply water connection 3rd filled so that heat from the sewage in the sewage rooms 7th on the supply water in the supply water rooms 6th can be transferred.

Finally, a final rinse step is carried out, during which water is supplied from the water supply spaces 6th in the recording room 1 is pumped. At the same time, wastewater comes out of the receiving room 1 in the sewage rooms 7th , which during the final rinse step via the siphon 14th is disposed of. Towards the end of the final rinse step, there are both the supply water spaces 6th as well as the sewage rooms 7th emptied.

3rd shows a section of a household dishwasher according to the invention, this being as follows from 1 distinguishes:

While in the case of 1 the waste water, which is via the siphon 14th is to be disposed of via a valve 16e into the sewer 12th reaches, the discharge of waste water takes place from the receiving space 1 in case of 3rd with the help of the pump 18th and over the valve 16i which also serves, depending on the position of the valve 16f the sewage in the sewage rooms 7th to pump. The valves 16g and 16h correspond to the valves 16c and 16d in 1 .

4th shows a further variant of the lower area of a household dishwasher according to the invention (the valves 16k and 161 correspond to the valves 16c and 16d in 1 , Valve 16y corresponds to valve 16b in 1 ). Here is a valve 16o present, which is opened when sewage from the receiving room 1 should be discharged. Is the valve 16n closed, so sewage from the receiving room can 1 with the valve closed 16y in the sewage rooms 7th be pumped. Is the valve 16y on the other hand, opened, so the waste water is from the pump 18th directly towards the siphon 14th pumped. Is the valve 16n on the other hand, when the valve 16m is closed, then when the pump is operated 18th Water from the sewage rooms 7th pumped out and towards the siphon 14th promoted.

5 FIG. 13 shows a further embodiment which differs from the embodiment according to FIG 1 differs in that in the supply water spaces 6th each a section of an evaporator 11 a heat pump arrangement runs. The remaining sections of the heat pump arrangement, already described above, are not shown. A heat transfer medium now flows through the evaporator 11 , so the heat transfer medium in the area of the supply water rooms 6th evaporates. As a result, the supply water is within the supply water spaces 6th cooled down and can partially freeze.

As the supply water rooms 6th but to the outside through the sewage rooms 7th are insulated, prevents humidity from getting out the environment of the household dishwasher condenses on its outer surfaces.

6th shows a course of the fill levels within the supply water spaces 6th and the sewage rooms 7th analogous to 2 , but applies to the in 2 embodiment shown. Like comparing 2 and 6th As can be seen, both differ in the course of the filling level within the supply water spaces 6th . During the filling level of the supply water within the supply water spaces 6th in case of 2 drops several times and then rises again, the level remains accordingly 6th constant over the course of the wash cycle. So supply water always comes through the supply water inlets 22nd in the recording room 1 in which it is through from below or through the three-way valve 20th coming section of the water supply line 4th incoming new supply water is displaced.

A final exemplary embodiment is finally shown in 7th shown. This figure clearly shows that the sewer room 7th can be formed for example by a meandering free space. The wastewater room shown on the right and left 7th is not an additional sewage room 7th , but only represents a side view of the sewage rooms 7th that are attached to the supply water rooms 6th connect. This representation is only chosen for a better overview, around the sewage rooms 7th to be able to represent better.

Furthermore, in the embodiment according to 7th provided that sewage from the receiving room 1 with the help of the pump 18th exclusively in the right sewage room 7th can be pumped. This in turn is connected to a section of the sewer line 12th with the left sewage room 7th connected. If wastewater is to be removed from the household dishwasher, this is done via a wastewater room on the left 7th connected section of sewer pipe 12th that ultimately ends up in the siphon 14th flows out. Finally, it should be noted that the valves 16p and 16q the valves 16c and 16d in 1 correspond. The valve 16r is opened when sewage from the receiving space 1 in the right sewer room 7th should be pumped.

In conclusion, some points of the present invention will be discussed again, with the following features being able to be implemented individually or in any combination (if technically possible and sensible) as required.

• - möglichst viel Abwasserenergie zurückgewinnen,
• - Verlängerung der Wärmeübergangszeit Versorgungswasser/Abwasser,
• - Verringerung der Versorgungswassermengen,
• - Dosierung der Füllmenge,
• - Zwischenspeichern von Wassermengen für Spülbad eines zeitlich später folgenden Teilspülgangs

Possible goals of the invention in a standard household dishwasher are:

• - recover as much wastewater energy as possible,
• - Extension of the heat transfer time supply water / waste water,
• - reduction of the supply water quantities,
• - Dosing of the filling quantity,
• - Intermediate storage of water quantities for the rinse bath of a subsequent partial rinse cycle

• - möglichst viel Abwasserenergie zurückgewinnen,
• - Verlängerung der Wärmeübergangszeit zwischen Versorgungswasser und Abwasser,
• - Verkürzung der Wärmeübergangs- bzw. Wärmeübertragungszeitdauer (durch Verdopplung der Wärmetauscherfläche, indem z.B. an der rechten und linken Seitenwandung des Spülbehälters jeweils eine Tankanordnung mit einem Versorgungswasserraum und einem Abwasserraum angebracht wird),
• - Verringerung der Versorgungswassermengen und damit Wasserverbrauchsreduzierung,
• - Dosierung der Füllmenge,
• - Wassermenge erhöhen, aus der latente Wärme entnommen werden kann (eine Kammer mit Versorgungswasserfüllung und eine zweite Kammer mit Abwasserfüllung; beide Kammern durch eine Wandung getrennt, die einen Wärmeübergang ermöglicht),
• - Kondensatbildung auf Spüleraußenseite reduzieren,
• - Klarspülerflotte (letzter Spülgang) für ersten Spülgang (Vorspülen) bereitstellen.

For a heat pump domestic dishwasher:

• - recover as much wastewater energy as possible,
• - Extension of the heat transfer time between supply water and wastewater,
• - Shortening the heat transfer or heat transfer time (by doubling the heat exchanger surface, e.g. by attaching a tank arrangement with a supply water space and a waste water space to the right and left side walls of the washing compartment),
• - Reduction of the supply water quantities and thus a reduction in water consumption,
• - Dosing of the filling quantity,
• - Increase the amount of water from which latent heat can be extracted (one chamber filled with supply water and a second chamber filled with waste water; both chambers separated by a wall that enables heat to be transferred),
• - Reduce condensation on the outside of the dishwasher,
• - Prepare rinse aid solution (last wash cycle) for the first wash cycle (pre-wash).

• Bei einer Standard-Haushaltsgeschirrspülmaschine:
  • - Es sind einkammrige Wärmetauscherbehälter bekannt, die Energie aus dem Spülbehälter sammeln und ebenfalls in den Stillstandszeiten zwischen den Spülgängen das Wasservolumen im Wärmetauscherbehälter von ca. 15°C Wasserleitungstemperatur auf bis Zimmertemperatur anheben.
  • - Weiterhin sind Dosier- oder Wärmetauscherbehälter bekannt, durch die der Ablaufschlauch geführt wird, um einen Wärmeaustausch zu ermöglichen. Hier hängt jedoch die Durchlaufzeit der Spülflotte von der Förderleistung der Laugenpumpe ab. Eine längere Standzeit der Spülflotte im Ablaufschlauch ist nur möglich, indem die Abwasserförderung in mehreren Unterbrechungen erfolgt. Hierbei würde sich das Spülprogramm erheblich verlängern. Ebenso ist dieses Teilabpumpen nur bei belüftetem Abwasserschlauch möglich.

Initial situation / similar known solutions:

• For a standard household dishwasher:
  • - There are single-chamber heat exchanger tanks that collect energy from the wash tank and also raise the water volume in the heat exchanger tank from approx. 15 ° C water line temperature to room temperature during the downtimes between wash cycles.
  • - Furthermore, dosing or heat exchanger containers are known through which the drain hose is passed in order to enable heat exchange. Here, however, the throughput time of the wash liquor depends on the delivery rate of the Drain pump off. A longer dwell time of the rinsing solution in the drain hose is only possible if the waste water is conveyed in several interruptions. This would extend the washing program considerably. This partial pumping is also only possible with a ventilated waste water hose.

• - Es sind Wasserbehälter bekannt, aus denen über einen Kältekreislauf spezifische und latente Wärmeenergien entnommen werden können.
• - Es sind zweikammrige Lösungen bekannt, bei denen eine Kammer als Isolator (nicht gefüllt) oder als Kondensorverstärker (gefüllt) während der Trocknung verwendet werden.
• - Es sind Wasserbehälter bekannt, aus denen über einen Kältekreislauf spezifische und latente Wärmeenergien entnommen werden können. Diese Wassermengen werden aber nicht dem Reinigungszyklus zur Verfügung gestellt. Es handelt sich um eine einmalige Füllung, die je nach Verdunstungsrate oder Überlaufrate (Volumenvergrößerung während des Gefrierens) nachgefüllt werden (V-Zug).

For a heat pump domestic dishwasher:

• - There are known water tanks from which specific and latent thermal energies can be taken via a cooling circuit.
• - Two-chamber solutions are known in which one chamber is used as an insulator (not filled) or as a condenser amplifier (filled) during the drying process.
• - There are known water tanks from which specific and latent thermal energies can be taken via a cooling circuit. However, these amounts of water are not made available to the cleaning cycle. It is a one-time filling that is refilled depending on the evaporation rate or overflow rate (volume increase during freezing) (V-Zug).

• Standard-Haushaltsgeschirrspülmaschine:
  • Ein bestehender Wärmetauscherbehälter / Füllmengen-Dosierbehälter / Wassermengenbereitschaftsbehälter / o.ä. wird über eine Trennwand in zwei Kammern geteilt. Dieser Behälter kann aus Metall, Kunststoff gespritzt, Kunststoff geblasen oder ähnlichem gefertigt sein. In einer der Kammern wird das Versorgungswasser deponiert und in einer weiteren, zweiten Kammer das abgepumpte Abwassers zum Verweilen zwischengespeichert. Während dieser Verweilzeit kann ein Teil der Abwasserenergie über die Trennwand an das Versorgungswasser bis zur Temperaturangleichung beider Mengen, übertragen werden.

Description of some possible aspects of the invention:

• Standard household dishwasher:
  • An existing heat exchanger tank / filling volume dosing tank / water volume standby tank / or similar is divided into two chambers by a partition. This container can be made of metal, injection-molded plastic, blown plastic or the like. The supply water is deposited in one of the chambers and the pumped-out wastewater is temporarily stored in a further, second chamber. During this dwell time, part of the wastewater energy can be transferred via the partition wall to the supply water until the temperature of both quantities is equal.

The waste water chamber can, however, also be formed by a preferably meandering, in particular partially tightly fitting, drainage hose or by a pipe that absorbs the amount pumped out so that it can be discharged into the siphon or a new rinse cycle at a later point in time and this creates a "pseudo" two-chamber solution. This meandering drainage pipe or this meandering drainage hose can in particular also be simulated by guide ribs in a container that temporarily stores the waste water. For this purpose, the guide ribs preferably follow one another with a gap and protrude alternately from a first wall and a second, opposite wall of the container, leaving a gap at their free ends to the opposite wall of the container. Other lead structures are also possible. In this way, the flow rate per container section can be increased and thus the dirt deposits can be minimized. This is particularly important if the same flow conditions are always present through the guide structures.

Before the next emptying of the washing compartment at the latest, the liquor chamber must be eliminated and available again empty.

Since the separation into two individual chambers makes the chambers smaller in terms of filling technology, such a heat exchanger should also be placed on the opposite side. As a result, the original volumes are achieved again. These 2 times 2 chambers are connected to each other in a communicating manner via hoses. Since the area of the heat-exchanging wall to the washing container is doubled by two systems, the heat transfer time is also shortened and the heat recovery from the inside of the container is improved.

With regard to energy supply, the supply water tank is connected to the washing tank wall for the sake of convenience. The dirty water tank sits adjacent to the side wall.

To improve the removal of dirt on the inside of the liquor heat exchanger, the waste water chamber can be given a "lotus effect" by means of a coating or structure.

The unfilled waste water chamber also serves as a heat insulator between the supply water tank and the side wall. At freezing temperatures, this minimizes condensation of the moisture-laden room air / outside air on the outside wall of the device without additional energy expenditure (heating foil, fan, insulating fleece, ...).

Instead of a water diverter outlet of a water diverter downstream of a circulation pump, the liquor heat exchanger can also be filled using an additional pump, in particular a drain pump, and two further waste water valves that are inserted into the feed lines to the two waste water chambers of the liquor heat exchanger.

• Dieselben Punkte wie bei der Standart-Haushaltsgeschirrspülmaschine zuzüglich folgender:
  • Die Wassermenge, aus der latente Wärmeenergie entnommen werden kann, ist vergrößert. Diese Volumina setzen sich aus Versorgungswasser und Abwasser zusammen, welche durch eine Behälterwand (Wärmeübergang gewährleistet) getrennt sind.

Heat pump household dishwasher:

• The same points as for the standard household dishwasher plus the following:
  • The amount of water from which latent heat energy can be extracted is increased. These volumes are made up of supply water and wastewater, which are separated by a container wall (heat transfer ensured).

When the latent heat energy has been removed and the domestic dishwasher has finished heating up, the dirty water chamber can be emptied. The ventilation takes place via the internal air in the washing container (warm). The waste water tank is therefore used for thermal insulation of the supply water tank, which has been cooled to 0 ° C, and the side wall. This is therefore only cooled for a short time and condensation of the outside air on the side wall of the device is by far prevented.

Cold water or wastewater that is about to freeze improves fat removal and removal from the wastewater heat exchanger thanks to its low viscosity.

Instead of using a water switch outlet, the liquor heat exchanger can also be filled using an additional pump, in particular a drain pump or two further dirt valves.

Likewise, the waste water container can be represented by meandering hoses or guide ribs, guide elements that reproduce an endless meander in a container. If both volumes are connected in series, the hydraulic prevalence can be kept easier.

Advantages of the invention:

• Standard household dishwasher:
  • - Label values are improved.
  • - The energy exchange time between supply water and wastewater can be kept much longer than with a pure pumping system (exception, the drain hose can hold the entire pumped volume and is controlled by an additional drain valve with drain ventilation. Otherwise the domestic dishwasher would be emptied by the suction lifter effect).
  • - The liquor heat exchanger can make the amount of rinse aid available to the pre-wash program.
  • - Since a heat exchanger is installed on the left and right of the household dishwasher with regard to the filling quantities, the heat transfer surfaces are doubled; the heat transfer time is thus halved.
  • - In the second filling step, the supply water temperature can be increased by the wastewater that is still stored. This also applies to subsequent steps in which the temperature of the filling medium is lower than that of the pumping medium.

• - Zusätzliche Punkte gegenüber Standard-Haushaltsgeschirrspülmaschine
• - Wärmeenergie im Abwasser unterstützt das Auftauen des Versorgungswasserwärmetauschers nachdem ein Teil bzw. die gesamte latente Wärme entzogen ist.
• - Leerer Flottenwärmetauscher dient als Wärmeisolierung zum Versorgungswasserwärmetauscher. Kondenswasser an der Spüleraußenseite wird verhindert.
• - Fast doppeltes Volumen, aus dem die latente Wärmeenergie entnommen werden kann.
• - Wärmepumpen-Folgespülgangswartezeit ist wesentlich verkürzt, da mehr Energie in den vier Wasservolumina zur Verfügung steht.
• - Kein Totwasser in der Haushaltsgeschirrspülmaschine (V-Zug). Fast alle zugeführten Wassermengen (Regeneriermenge) werden für den Spülprozess verwendet.
• - Die Energie, die die Wärmepumpe zum Aufheizen verwendet, wird nicht dem Raum, sondern überwiegend dem Zulaufwasser und Abwasser entzogen. Es kommt daher zu keiner merklichen Abkühlung des Raumklimas am Standort der Haushaltsgeschirrspülmaschine bei Betrieb deren Wärmepumpe.
• - Durch das größere Temperaturdelta Behälter (Prozesstemperatur) / Wärmetauscher (0°C) wird mehr Wärmeenergie in den Wärmetauscher transferiert als durch den Türaufbau nach außen verloren geht. Das heißt, mehr Energie wird im System zurückgehalten bzw. der Folgespülgang kann nach kürzerer Zeit erneut starten.

Heat pump household dishwasher:

• - Additional points compared to a standard household dishwasher
• - Thermal energy in the wastewater supports the thawing of the supply water heat exchanger after some or all of the latent heat has been withdrawn.
• - Empty liquor heat exchanger serves as thermal insulation for the supply water heat exchanger. This prevents condensation on the outside of the dishwasher.
• - Almost twice the volume from which the latent heat energy can be taken.
• - Heat pump follow-up rinse waiting time is significantly reduced as more energy is available in the four water volumes.
• - No dead water in the household dishwasher (V-Zug). Almost all of the supplied water quantities (regeneration quantity) are used for the rinsing process.
• - The energy that the heat pump uses for heating is not withdrawn from the room, but mainly from the inlet water and waste water. There is therefore no noticeable cooling of the room climate at the location of the household dishwasher when its heat pump is in operation.
• - Due to the larger temperature delta container (process temperature) / heat exchanger (0 ° C), more heat energy is transferred into the heat exchanger than is lost to the outside through the door structure. This means that more energy is retained in the system or the next wash cycle can start again after a shorter time.

In addition, the invention is not limited to the illustrated embodiment. Rather, all combinations of the individual features described, as shown or described in the claims, the description and the figures and as far as a corresponding combination appears technically possible or sensible, are the subject matter of the invention.

List of reference symbols

1

Recording room

2

Items to be washed

3

Supply water connection

4th

Supply water pipe

5

Tank arrangement

6th

Supply water room

7th

Sewage room

8th

Outer wall

9

partition wall

10

Sidewall

11

Evaporator

12th

Sewer

13th

Waste water connection

14th

siphon

15th

Sewage pump

16a-16r

Valve

17th

check valve

18th

Pump, in particular a circulating pump and, if necessary, a water switch connected to it

19th

Water softener

20th

Three-way valve

21

Safety valve

22nd

Supply water inlet

23

Sewage inlet

Claims (14)

Domestic dishwasher with a receiving space (1) for receiving items to be washed (2), and with a water supply line (4) for supplying the domestic dishwasher with water from a water supply connection (3) connected to the water supply line (4) during operation of the domestic dishwasher, characterized in that the domestic dishwasher has at least one tank arrangement (5), the tank arrangement (5) having a supply water space (6) for receiving supply water from the supply water line (4) and a waste water space (7) for receiving waste water from the receiving space (1), wherein the supply water space (6) and the waste water space (7) are in a thermally conductive connection in order to enable a heat transfer from the waste water in the waste water space (7) to the supply water in the supply water space (6). Domestic dishwasher according to the preceding claim, characterized in that the supply water space (6) is arranged at least in sections between the receiving space (1) and the waste water space (7). Domestic dishwasher according to one of the preceding claims, characterized in that the domestic dishwasher has an outer wall (8) which closes off the domestic dishwasher to the outside, the waste water space (7) being arranged between the outer wall (8) and the supply water space (6). Domestic dishwasher according to one of the preceding claims, characterized in that the tank arrangement (5) has at least one partition (9), a first side of the partition (9) the waste water space (7) and a second side of the partition (9) the supply water space ( 6) limit each section. Domestic dishwasher according to one of the preceding claims, characterized in that the domestic dishwasher has two tank arrangements (5), a first tank arrangement (5) in the region of a first side wall (10) of the domestic dishwasher and the second tank arrangement (5) in the region of a second side wall ( 10) the household dishwasher is arranged. Domestic dishwasher according to one of the preceding claims, characterized in that the domestic dishwasher comprises a heat pump arrangement through which a heat transfer medium flows during its operation, the heat pump arrangement including, among other things, an evaporator (11) which is arranged at least in sections within the supply water space (6) or is in a thermally conductive connection with it, and with the help of which heat can be transferred from the supply water to the heat transfer medium. Domestic dishwasher according to one of the preceding claims, characterized in that the waste water space (7) is connected to a waste water line (12) which connects the waste water space (7) with the receiving space (1). Domestic dishwasher according to the preceding claim, characterized in that the wastewater space (7) is also connected to a wastewater connection (13) of the domestic dishwasher via the wastewater pipe (12), via which the wastewater during operation of the Household dishwasher can be removed from the household dishwasher. Method for operating a domestic dishwasher with a receiving space (1) for receiving dishes (2), and with a water supply line (4) via which the domestic dishwasher supplies water from a water supply connection (3) connected to the water supply line (4) during operation is, characterized in that the domestic dishwasher has at least one tank arrangement (5), the tank arrangement (5) having a supply water space (6) for receiving supply water from the supply water line (4) and a waste water space (7) for receiving waste water from the receiving space (1), wherein during a wash cycle, heat is transferred at least temporarily from the waste water in the waste water space (7) to the supply water in the supply water space (6). Method according to the preceding claim, characterized in that the supply water present in the supply water space (6) is at least partially released into the receiving space (1) after heat has passed from the waste water to the supply water. Procedure according to Claim 9 or 10 , characterized in that the supply water present in the supply water space (6) is at least partially released into the receiving space (1) after between 40% and 70% of the latent heat quantity of the waste water has passed to the supply water. Method according to one of the Claims 9 to 11 , characterized in that the waste water present in the waste water space (7) is at least partially discharged from the domestic dishwasher and / or released into the receiving space (1) after heat has passed from the waste water to the supply water. Method according to one of the Claims 9 to 12th , characterized in that waste water from the waste water space (7) is discharged at least partially and / or temporarily directly and without passing through the receiving space (1) into the waste water line (12). Method according to one of the Claims 9 to 13th , characterized in that the household dishwasher comprises a heat pump arrangement through which a heat transfer medium flows during its operation, the heat pump arrangement including, among other things, an evaporator (11) which is arranged at least in sections within the supply water space (6) or in a thermally conductive connection with it stands, and with the help of which heat is at least temporarily transferred from the supply water to the heat transfer medium during a wash cycle.

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