Dishwasher comprising a heat pump
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- BSH HAUSGERATE GMBH
- Filing Date
- 2024-08-02
- Publication Date
- 2026-06-17
Smart Images
Figure EP2024072012_13022025_PF_FP_ABST
Abstract
Description
[0001] Dishwasher with a heat pump
[0002] The present invention relates to a dishwasher with at least one heat pump according to the preamble of claim 1.
[0003] It is known that dishwashers can be equipped with heat pumps to optimise their energy efficiency. This can at least support the heating of the circulating dishwashing liquid in the dishwasher or, with appropriate design, can even be achieved entirely via the heat pump. Such a heat pump is usually an air-water heat pump, which extracts heat from the ambient air and transfers it to the dishwashing liquid to be heated. However, this brings with it the problem that this ambient air (often underneath kitchen units) is cooled at the heat pump, particularly at the evaporator, due to the removal of thermal energy. A high level of heat pump efficiency is therefore very important. In particular, the heat transfer from a working medium of the heat pump to the dishwashing liquid or dishwater to be heated in the condenser of the heat pump must be as loss-free as possible.Nevertheless, the space for the heat pump remains very limited, so that the solution can only take up a small amount of space.
[0004] The invention is based on the problem of designing a heat pump for a dishwasher to transfer heat to the washing liquor in the condenser very effectively while requiring little installation space.
[0005] The invention solves this problem by a dishwasher having the features of claim 1. With regard to advantageous embodiments and further developments of the invention, reference is made to the further claims 2 to 22.
[0006] Because according to the invention in a dishwasher with at least one heat pump it is provided that for heat transfer to the washing liquid or washing liquor at least one line area is provided for this, which runs parallel to at least one line area for the working medium of the heat pump, wherein both line areas are cast or overmolded or soldered to one another via a heat-conducting material, a good heat-conducting composite of one or more line areas for washing liquor and one or more line areas for the working medium is created.
[0007] In particular, the potting or overmolding material fulfills a dual function of thermal conductivity and mechanically securing the line sections or line sections to one another. Additional mechanical fasteners between the line sections or line sections are then not absolutely necessary. Potting or overmolding the parallel line sections (for the working medium and for the flushing liquid) along their longitudinal course with heat-conducting material advantageously leads to the formation of a pipe string which, viewed in cross-section over its longitudinal course, contains these parallel line sections (for the working medium and for the flushing liquid) completely within its potting or overmolding material. This means that the parallel line sections (for the working medium and for the flushing liquid) are completely embedded in the heat-conducting potting or overmolding material or are completely surrounded by it.They are therefore completely encased along their length by the potting or overmolding material and thus tightly enclosed by it. The potting or overmolding material forms a jacket or an enveloping material layer all around the parallel line sections and sits firmly and tightly on them. This allows heat to be transferred from the entire jacket surface of the respective line section carrying the working medium to the entire jacket surface of the at least one line section carrying the flushing liquid by means of the thermally conductive potting or overmolding material enveloping them. In particular, the heat emitted by the one or more line sections carrying the working medium can be transferred at least almost completely to the at least one line section carrying the flushing liquid.In this way, the heat transfer from the respective line area for working medium to at least one line area for flushing liquid can be improved.
[0008] It can be particularly expedient if, viewed in cross-section, the parallel line sections (for the working medium and for the flushing liquid) are enclosed on all sides with a thickness of the casting or overmolding material that remains constant over the length of the pipe string. In particular, it can be advantageous in terms of connection technology if connections, in particular a pair of connections, for supplying the flushing liquid and for supplying the working medium into the line sections are led out of the casting or overmolding material from the inlet-side, front end of the pipe string, and connections, in particular a pair of connections, for discharging the flushing liquid and for discharging the working medium from the line sections are led out of the casting or overmolding material from the outlet-side, front end of the pipe string.This makes it easy to install the pipe string acting as a heat exchanger between the working medium and the rinsing liquid, on the inlet and outlet sides, into the connecting line between the compressor and the expansion device of the heat pump, as well as into a rinsing liquid line, in particular into a rinsing liquid-carrying bypass circuit branching off from the circulation circuit of the dishwasher.
[0009] Alternatively, if at least one pipe section for the heat pump's working medium and at least one pipe section for the rinsing liquid are soldered together using solder, the solder also fulfills a dual function of thermal conductivity and mechanically securing the pipe sections to one another. In this case, solder may only be applied to the facing contact surfaces of the pipe sections to ensure sufficient heat transfer between the pipe section for the working medium and the pipe section for the rinsing liquid. Therefore, a complete coating of the parallel pipe sections with solder is not mandatory, but possible.
[0010] Particularly advantageously, the potting or overmolding compound connecting the line areas (for flushing liquid and for working medium) keeps adjacent line areas (for flushing liquid and for working medium), which are jointly wrapped or encased by the potting or overmolding compound, at a distance of less than ten millimeters, measured transversely to their course, in particular significantly less, so that as little heat as possible remains in the potting or overmolding material or soldering material, but as much heat as possible from the respective line area carrying the working medium is transferred directly and as completely as possible to the flushing liquid in the adjacent, parallel line area carrying the flushing liquid by heat conduction over the shortest possible route.In particular, it may be expedient if, within the casting or overmolding material, the at least one line region for the working medium contacts the at least one line region for the rinsing liquid assigned to it, ie their outer jacket surfaces lie against one another.
[0011] The casting or overmolding compound connecting the cable areas is very advantageously made of cast aluminum, which, in addition to good mechanical properties and a low density, has very good thermal conductivity.
[0012] Alternatively, zinc die casting can also be used for this connecting casting or overmolding compound.
[0013] If at least one line section for the working medium of the heat pump and at least one line section for the rinsing solution are soldered together using soldering compound, tin or silver solder can be used as the soldering compound.
[0014] If the pipe sections, which are cast, overmolded, or soldered together, particularly to form a common pipe string, form straight or curved pipe sections or pipe sections, within which at least one section of the pipe section for the rinsing solution and at least one section of a pipe section for the working medium are run parallel to one another, these pipe sections or pipe sections can be combined to form a compact, coherent structural unit with minimal space between the pipe sections or pipe sections. This structural unit can be constructed differently depending on the available installation space; if necessary, it can also be angled.
[0015] If the cast, overmolded, or soldered at least one line section for the heat pump's working medium is designed as a copper line, the entire line section for the working medium can be made of copper throughout the heat pump, completely eliminating foreign material transitions in the working medium circuit between the heat pump components. For good heat conduction and high stability, the cast, overmolded, or soldered at least one line section for the rinsing solution can be designed as a stainless steel line. This is also advantageously corrosion- and alkali-resistant.
[0016] As explained above, the cast or over-molded or soldered area, which is formed between the at least one line area through which the rinsing liquid or rinsing liquor flows or can flow through and the at least one line area running parallel thereto through which the working medium of the heat pump flows or can flow through by casting or over-molded or over-molding or soldering by means of a thermally conductive, i.e. heat-conductive material, forms a heat exchanger of the heat pump, in which the working medium releases heat to the rinsing liquor and in the process changes from its gas phase into its liquid phase.In the context of the invention, the term heat exchanger is understood to mean, in particular, a heat transfer unit which assigns at least one line region of the heat pump through which the working medium flows or can flow, in which the working medium of the heat pump releases or can release heat to the outside, to at least one line region running parallel thereto through which rinsing liquid to be heated flows or can flow, wherein the at least one line region for the working medium and the at least one line region running parallel thereto for the rinsing liquid to be heated are cast or over-molded or soldered together by means of a heat-conducting material.The at least one line region for the working medium, in which the working medium of the heat pump releases or can release heat to the outside, and the at least one line region for the rinsing liquid, which runs parallel to this and is firmly connected to this by means of the heat-conducting material, thus form in particular a common strand unit with a heat transfer function.
[0017] In order to realize the desired compact structural unit of the heat exchanger, i.e., the heat transfer unit, the pipe sections (for the working medium and for the flushing fluid) that are cast, overmolded, or soldered together, which in particular each form pipe sections or pipe sections of a common pipe string, are preferably laid in a meandering course according to an advantageous development. Alternatively, the pipe sections (for the working medium and for the flushing fluid) that are cast, overmolded, or soldered together, which in particular form pipe sections or pipe sections of a common pipe string, can preferably be laid in a spiral course according to an advantageous development.
[0018] In summary, according to an advantageous development of the invention, the pipe sections cast, overmolded, or soldered together preferably form a common pipe string, which runs in particular in a meandering or spiral manner. Thus, the heat transfer unit, which is formed by the at least one pipe section or pipe section of the condenser through which the working medium flows or through which it flows, and the at least one pipe section through which the washing liquid flows or through which it flows, can have a desired compact geometric shape, so that it requires very little space—particularly in the base support of the dishwasher below its washing container.
[0019] The cable sections cast, overmolded or soldered together to form the common strand unit can each have a total length of several meters despite the compact external dimensions of the strand unit itself.
[0020] In particular, the duct sections cast, overmolded, or soldered together can result in a flat structure of low overall height formed by meanders or spiral windings, thus optimally utilizing the available space for accommodating the heat pump, in particular its condenser, in the dishwasher. In particular, the flat structure can be formed two-dimensionally. It can then, for example, be advantageously arranged in an at least approximately horizontal plane in the base support of the dishwasher below the bottom wall of the washing container, thus saving overall height.
[0021] To minimize the amount of space required in the dishwasher, the flat structure can be positioned, in particular, directly below the washing tub—especially in the so-called base support or appliance base of the dishwasher—when installed. For this purpose, the flat structure ideally has a maximum height of five centimeters. The lateral edge length of the flat structure, however, can be several tens of centimeters.
[0022] The flat structure can also be three-dimensionally formed, e.g. if the space available in the base support for accommodating the heat exchanger requires this.
[0023] Alternatively, the cable sections that are cast, overmolded, or soldered together can be formed into a spiral, flat structure.
[0024] According to an advantageous development, two parallel conduit sections for the working medium are assigned to each conduit section for the rinsing solution or rinsing liquid in the casting or injection compound or soldering compound, so that three conduit sections are adjacent to one another in cross-section. In particular, the conduit section for the rinsing solution can be located—preferably centrally—between two conduit sections for the working medium and thus advantageously receive heat input from two opposite sides.
[0025] It can also be advantageous if the flat structure is inclined and / or shaped in such a way that the line area contained therein for rinsing liquor or rinsing liquid drains automatically in a depressurized state, i.e. when the rinsing liquid is no longer pumped by a feed pump because the pump is switched off. Then, after the respective rinsing phase of a particular dishwashing program, during which the heat pump was in operation to heat up the rinsing liquid, no rinsing liquor remains in the line area. The risk of dirt residues contained in the rinsing liquid, in particular organic substances, rotting or the risk of dirt being transferred to the dishes in the next rinsing phase of the dishwashing program or in the rinsing cycle, i.e. in one or more rinsing phases, of the next dishwashing program, is minimized.
[0026] Depending on the installation situation, it is possible that a line section for rinsing liquor and one or more line sections for working medium are arranged one above the other in the flat structure, in particular in an at least approximately vertical plane, so that the overall structure of the pipe parts or pipe sections of the pipe string of the heat exchanger can be kept very narrow.
[0027] Alternatively, a line section for rinsing liquor and one or more line sections for working medium are arranged next to each other in the flat structure, so that the installation height of the heat exchanger is very low.
[0028] If the line section for rinsing solution has a larger cross-sectional area than the or each line section for working medium, a relatively large flow rate of rinsing solution can be passed through and heated.
[0029] If the line section for rinsing liquor and / or the or each adjacent horizontal line section for working medium are flat oval in cross-section and the long axes of the respective oval are parallel to each other, enlarged surfaces of the different line sections face each other in order to optimize heat transfer.
[0030] For energy efficiency, it is optimal if the line section for rinsing liquid and the or each line section for working medium operate according to the countercurrent principle.
[0031] Other advantageous developments and further developments of the invention are set out in the subclaims.
[0032] The advantageous embodiments and further developments of the invention explained above and / or reproduced in the subclaims can be used individually or in any combination with one another - except, for example, in cases of clear dependencies or incompatible alternatives.
[0033] The invention and its advantageous developments and further developments as well as their advantages are explained in more detail below with reference to drawings showing exemplary embodiments.
[0034] They show, each in a schematic principle sketch: Fig. 1 a schematic perspective view diagonally from the front of an embodiment of a household dishwasher shown here as an example with a door that can be swung downwards and a base or base support for accommodating functional elements such as a heat pump in the lower area,
[0035] Fig. 2 is a schematic block diagram of a dishwasher with heat pump, with an optional condensate collection tray provided below the evaporator,
[0036] Fig. 3 shows a heat exchanger constructed as a flat structure, which is formed from a meandering pipe string, in the interior of which pipe areas for rinsing liquor and for working medium are located adjacent to each other and run parallel to each other, wherein the flat structure is adapted in its entire external shape to an available installation space,
[0037] Fig. 4 the structure or the assembly according to Figure 3 from a slightly rotated perspective,
[0038] Fig. 5 the structure or the assembly according to Figure 3 in a view from above,
[0039] Fig. 6 shows a cross-section through the pipe string of Figures 3 - 5 with two pipe sections for working medium, which are located above and below a pipe section for rinsing liquor, wherein the pipe sections are all oval and the long axes of the ovals are parallel to each other, and
[0040] Fig. 7 shows a heat exchanger constructed as a flat structure, consisting of a spiral-shaped pipe string, within which conduit sections for the rinsing solution and the working medium are located adjacent to each other and run parallel to each other. The flat structure's overall external shape is adapted to the available installation space. Elements with the same or comparable function and mode of operation are provided with the same reference numerals in the figures.
[0041] Figure 1 shows an example of a dishwasher 1, namely a household dishwasher, without the invention being limited thereto. If appropriate, it can be applied to another household appliance, such as a washing machine or a washer-dryer, in which a liquid is to be heated in an energy-efficient manner.
[0042] The household dishwasher according to Figure 1 described below has, as part of a partially outwardly open or closed appliance body 5, a washing container 2 for holding items to be washed, such as dishes, pots, cutlery, glasses, cooking utensils, etc. The items to be washed can, for example, be held in dish baskets 11, in particular in a lower dish basket UG and in an upper dish basket OG arranged at a free height above this (see Figure 2), and / or in a cutlery drawer 10, and can be exposed to so-called rinsing liquor or rinsing liquid 24. Depending on the partial rinsing phase of a dishwashing program to be carried out, the rinsing liquor or rinsing liquid 24 is used.Rinse liquid 24 is understood to mean fresh water or, in particular, water circulating during operation, with or without cleaning agent and / or rinse aid and / or drying agent, i.e. all liquid that comes into contact with the items to be washed during the respective partial rinse phase. In particular, the rinse liquid 24 can have passed through an ion exchanger or other softening device for softening. The rinse liquid 24 can also be mixed to a greater or lesser extent with soiling from ongoing operation. The rinse container 2 can have an at least essentially rectangular floor plan with a front V facing a user in the operating position. This front V can form part of a kitchen front made up of adjacent kitchen units or, in the case of a stand-alone appliance, can also be without any reference to other units.
[0043] The loading opening of the washing container 2, which in this exemplary embodiment is preferably on the front, can be closed on this front side V by a (front) door or flap 3. This door 3 is shown in Figure 1 in a partially open position and then at an angle to the vertical. In its final closed position, however, it stands at least almost vertically upright and, as shown in Figure 1, can be pivoted forwards and downwards in the direction of arrow 4 about a lower horizontal axis to open it, so that in the fully open position (final opening position) it is at least almost horizontal. Other movements of the door are also possible, including via a parallelogram or other multi-joint arrangement. Of course, a side-hinged door or an opening of the washing container 2 facing upwards can also be provided as an alternative.
[0044] On the outer and front side V of the dishwasher 1, which is at least almost vertical in the final closed position and faces the user, the front door 3 can be provided with a decorative panel 6 - as here in the embodiment of Figure 1 - in order to thereby experience a visual and / or haptic enhancement and / or adaptation to surrounding kitchen furniture.
[0045] The dishwasher is designed here only as an example as a stand-alone household appliance standing on the floor B or as a so-called partially integrated appliance, which is preferably installed standing on the floor B within a built-in niche between adjacent kitchen units below a kitchen worktop. The kitchen units and the kitchen worktop have been omitted from Figure 1 for the sake of simplicity of the drawing. In the lower area of the dishwasher 1, below the washing tub 2, there can be a base or a base support 12, in particular for accommodating functional elements, such as a pump for circulating the washing liquor and / or a pump for extracting the washing liquor from a pump sump PS fluidically connected to the washing tub 2, and also the heat pump or heat pump arrangement 14 designed according to the invention. This does not necessarily have to be arranged in the base 12, depending on the design of the dishwasher 1.In Figure 1, the heat pump or heat pump assembly 14 is symbolized only by a dot-dash rectangle in the base support or device base 12. Figure 2 shows it and its components in detail.
[0046] In the exemplary embodiment according to Figure 1, the upper region of the movable door 3 is assigned an outer panel 8 which extends in the transverse or width direction Q of the dishwasher and which can comprise, in particular cover, both displays and operating elements and then also serves as an operating panel. In the region of its lower edge, as here in the exemplary embodiment of Figure 1, an access opening 7 accessible from the front V for manually opening and / or closing the door 3 can expediently be provided. The access opening can in particular be integrated into the panel 8, i.e. be a component of the panel. This access opening 7 can extend at least almost across the entire width in the transverse direction Q, for example 50 to 60 centimeters, although this is not mandatory. An access opening 7 extending only in the transversely central region - as shown here in Figure 1 - is also possible.
[0047] In the transverse direction Q, the dishwasher often has an extension of 45, 50 or 60 centimeters. In the depth direction from the front V to the rear, the extension is often also around 60 centimeters. These values are not mandatory. Furthermore, the dishwasher 1 does not have to stand directly on a floor B, but can also be located on a kitchen unit base or installed higher up within a kitchen unit with a height clearance from floor B that requires the user to bend down less or not at all when loading or unloading the lower dish basket of the dishwasher. The lower edge of the dishwasher 1 is then preferably approximately 30 to 120 centimeters above floor B when installed or installed in this raised position relative to floor B. The vertical height H of the dishwasher 1 can also vary.
[0048] The washing chamber of the washing container 2 is delimited by its three fixed or stationary vertical walls 13 (two side walls and one rear wall), two horizontal walls 13, one of which forms a ceiling (top) and another a floor (bottom) of the washing container 2, and by the so-called inner door wall of the pivoting front door in its at least almost vertically closed end position. Adjacent to the front side V facing the user in the transverse direction Q are a left, at least approximately vertically upright side wall 13 to the left and a right, at least approximately vertically upright side wall 13 to the right.
[0049] In the washing chamber of the washing container 2, one or more liquid application units, in particular spray devices such as, in this exemplary embodiment, a lower rotating spray arm US assigned to the lower dish basket UG, an upper rotating spray arm OS assigned to the upper dish basket OG, and above the upper cutlery drawer 10, a roof sprayer or a rotating roof gyroscope DK in the region of the ceiling wall of the washing container 2, are provided (see Figure 2). These liquid application units are supplied with washing liquid 24 via one or more supply lines such as ZL1, ZL2.For this purpose, a circulating pump UP, when in operation, sucks in rinsing liquid from a pump sump PS or liquid collection area which is fluidically connected to the washing chamber, and this rinsing liquid is pumped via a water switch preferably integrated into the circulating pump UP or, as here in the embodiment of Figure 2, via a water switch WS fluidically arranged downstream of the circulating pump UP in its conveying direction, optionally into the feed line leading to the respective liquid application unit selectively, i.e. individually, or into several feed lines leading to a subgroup of several liquid application units at the same time, or into all feed lines leading to the liquid application units at the same time. According to the embodiment of Figure 2, the pump sump PS is arranged below an outflow opening provided in the bottom wall of the washing container 2 and is fluidically connected to this.This outflow opening and / or the pump sump can expediently be provided with a filter system, which has been omitted in Figure 2 for the sake of simplicity of the drawing. Here in the embodiment of Figure 2, for example, rinsing liquid 24 is conveyed to the lower, rotatable spray arm US via the supply line ZL1 when the water diverter WS is moved to a corresponding, first position and the circulation pump UP is running. The upper, rotatable spray arm OS as well as the roof shower or the rotatable roof rotor DK are preferably supplied with rinsing liquid via the common supply line ZL2 when the water diverter WS is moved to a corresponding, second position and the circulation pump UP is running. Of course, it is also possible to deviate from this and supply the upper, rotatable spray arm OS as well as the roof shower or the rotatable roof rotor DK with rinsing liquid, each with its own supply line, via the water diverter WS.If other or further liquid supply units are provided in the wash chamber, separate or dedicated supply lines can run to each of them starting from the water diverter WS, or at least a subgroup of these liquid supply units can be supplied with washing liquid via a common supply line starting from the water diverter WS. In this way, the wash chamber of the wash tub 2, the pump sump PS, the circulating pump UP, the water diverter WS, the one or more supply lines or liquid distribution lines such as ZL1, ZL2, as well as the one or more liquid supply units arranged in the wash chamber of the wash tub 2, such as US, OS, DK, form a liquid circulation circuit or a hydraulic circuit HK for supplying the wash ware in the wash chamber with washing liquid. The circulating pump UP is preferably in operation when the wash ware is to be supplied with washing liquid.
[0050] The dishwasher 1 is equipped with at least one heat pump or heat pump arrangement, which is designated overall by the reference numeral 14 and is shown only roughly schematically in Figure 2 in an exemplary embodiment. With its help, the washing liquid present in the circulation circuit or hydraulic circuit during at least one liquid-carrying partial washing phase, such as the cleaning phase and / or final rinse phase of a dishwashing program to be carried out, is to be heated to a desired target final temperature. In this exemplary embodiment, the heat pump 14 is in particular a compressor pump, i.e., it comprises a compressor or condenser 16, with which mechanical work can be performed on a working medium 17, for example a propane / butane mixture, circulating in the heat pump 14. The compressor 16, in which the mechanical work is performed on the working medium 17, is electrically driven.
[0051] In addition to the compressor 16, the heat pump or heat pump assembly 14 comprises at least one condenser 18, an expansion device or expansion element 19, for example, an expansion valve or a capillary, and an evaporator 20. These functional units 16, 18, 19, 20 are interconnected via line regions or line sections 21 for conveying a working medium 17 that changes state during operation. A dryer cartridge TP can expediently be inserted into the line section between the condenser 18 and the expansion device 19. This is indicated by a dash-dotted line in Figure 2. The working medium 17 flowing through the heat pump assembly 14 during its operation (compressor 16 is switched on) is symbolized in Figure 2 by a separately shown arrow, which also indicates its flow direction.The heat pump 14 is also assigned at least one supply line 22 and one discharge line 23 for rinsing liquid 24 circulating in the household appliance, as well as an electrical connection 25. The electrical connection 25 can be used, in particular, to supply the compressor 16 with electrical energy for its operation. The supply line 22 diverts rinsing liquid 24 from the circulation circuit HK into a bypass circuit BK, which runs parallel to the bypass circuit in terms of fluid flow, and there guides it through a heat transfer line section WT that is in thermal contact with the condenser 18.The condenser 18 and the heat transfer line section WT through which the rinsing liquid flows or (when the circulation pump UP is switched on) through which it flows thus form a heat exchanger HTU in which, during operation of the heat pump 14 (when the compressor 16 is switched on), heat is transferred from the working medium 17 to the rinsing liquid 24 flowing through the heat transfer section WT, in particular pumped by the circulation pump UP. From the outlet of the heat exchanger line section WT, the rinsing liquid 24 heated by the condenser 18 is returned via the discharge line 23 to the rinsing tank 2 or to another point in the circulation circuit HK.It can be particularly advantageous if the supply line 22 - as schematically indicated in Figure 2 - branches off from the internal liquid conveying channel of the circulating pump UP (viewed in the conveying direction), preferably immediately behind its impeller chamber and thus on the pressure side, preferably before its downstream diffuser chamber, via a specially provided outlet opening as a bypass line. A valve VA can expediently be inserted into this supply line 22 - as here in the embodiment of Figure 2. With its aid, the flushing liquid flow caused during conveying operation of the circulating pump UP through the supply line 22 to the heat transfer line section WT can be enabled or disabled, i.e. the bypass circuit BK can be opened or closed.The rinsing fluid 24 flowing through the circulation circuit HK and through the bypass circuit BK is symbolized in Figure 2 by separately shown arrows, which also indicate the flow direction of the rinsing fluid in the circulation circuit HK, which serves to distribute rinsing fluid in the wash cabinet, and in the bypass circuit BK, which includes the thermal coupling between the condenser 18 and the heat transfer line section WT carrying the rinsing fluid for heating the rinsing fluid by means of the heat pump. In addition, the heat pump arrangement 14 can optionally include various sensors and a connection for a communication interface, in particular for a data bus—neither of which are shown.
[0052] The flushing liquid 24 to be heated expediently passes through the heat transfer line section WT in the countercurrent principle to the working medium 17 in the condenser 18. In this way, an efficient, ie highly effective, transfer of the heat of the working medium 17 to the flushing liquid 24 is ensured.
[0053] This heat pump 14, in particular its essential components such as 16, 18, 19, 20, 21, can, as shown schematically in Figure 2, form a modular unit and can be pre-assembled before installation in the dishwasher 1, filled with working medium 17 and either testable for function or, in particular, already tested for function before installation. For this purpose, the entire heat pump unit or heat pump arrangement can be held on a common support 15 for the parts of the heat pump 14. The valve VA, the supply line 22, and / or the discharge line 23 can, but do not have to, be part of the pre-assembled heat pump arrangement 14, but can also be connected to the hydraulic circuit HK only after the heat pump arrangement 14 has been inserted into the dishwasher - preferably into the base support of the dishwasher - during manufacture of the dishwasher.
[0054] Further units associated with the components of the heat pump arrangement 14 can also be provided, in particular fastened or mounted, on this support 15, such as on a support frame or on a support plate. Thus, according to Figure 2, an optional condensate collection tray AW is mechanically fixedly attached to the support 15, in particular on a support plate, below the evaporator 20. In particular, it can be molded onto the support 15, in particular onto the support plate. This is particularly advantageous if the support 15, in particular the support plate, is made, for example, from a plastic material.
[0055] Depending on its design, the condensate collecting tray AW can also be located below the support or support unit 15. If necessary, it can also be a component of the base support 12, in particular its bottom wall. In particular, it can be molded onto it. This is advantageous if the structure of the base support 12 is made of plastic material. The support unit 15, in particular the support plate, then expediently ends before the drip area of the evaporator 20, i.e. above the condensate collecting tray AW, the support unit 15, in particular the support plate, is missing below the drip area of the evaporator 20, or it is cut out there or has a recess there so that the condensate forming on the evaporator during operation of the heat pump can drip down into the condensate collecting tray AW.Condensate accumulating in the area of the evaporator 20 during operation of the heat pump arrangement 14 and collected in the condensate collection tray AW below it can be returned to the rinsing tank 2, for example, via a condensate pump KP and a liquid line (return line) KL connected to it. The condensate pump KP can be mechanically fixedly mounted in the condensate collection tray AW or outside of it on the support unit 15, in particular on the support plate, or at a location in the base support 12.
[0056] In addition to the components mentioned, the heat pump 14 comprises at least one air conveying device 26 which is assigned to the evaporator 20. The air conveying device 26, in particular a fan, ensures that ambient air is blown along the line regions or line sections of the evaporator 20 through which the working medium can flow or through and / or along fins protruding from these, whereby heat is extracted from the ambient air and transferred to the working medium 17. The air conveying device 26 is expediently arranged in this exemplary embodiment such that, during its ongoing operation, ambient air from the space surrounding the dishwasher 1 is drawn in through front ventilation slots 31 and / or through gaps, cracks, recesses and / or openings in the one or more walls of the base support orappliance base of the dishwasher and is preferably blown backwards (in the depth direction of the dishwasher) to the evaporator 20 and flows along its one or more, preferably meandering, line areas or line sections through which the working medium can flow or through and / or along the fins protruding from these. After passing through the evaporator 20, ie through the gaps between its one or more line areas and / or between the fins protruding from these, the ambient air cooled by the evaporator 20 exits through the rear wall R of the dishwasher - here in the exemplary embodiment preferably through a recess or opening in the rear wall R of the dishwasher 1 - to the outside into the environment of the dishwasher.
[0057] Figures 3 to 6 show an individual part of the structural unit of the heat exchanger HTU formed between the condenser 18 and the line section WT through which the rinsing liquid 24 can flow or through. This shows that this heat exchanger HTU has connections 22', 23' for the supply line 22 and the discharge line 23 for rinsing liquid 24. For heat transfer to the rinsing liquid 24, at least one line section or line section 27 is provided for this, which runs parallel to at least one line section 21 for working medium 17, i.e. parallel to one or more line sections 21 for working medium, of the heat pump, wherein both line sections, i.e. the line section for rinsing liquid 24 and the line section for working medium 17, are cast or overmolded or soldered together via a heat-conducting material 28 to form a common pipe string.This common pipe string forms the heat exchanger HTU for transferring heat from the working medium 17 to the flushing liquid 24. This casting or overmolding compound or soldering compound 28 connecting the line sections 21, 27 fulfills both a thermally conductive function and a mechanically holding the line sections 21, 27 together function, so that a preferably flat structure 32 shown in Figures 3 - 6 and formed from the pipe string is permanently dimensionally stable. This preferably flat structure 32 forming the heat exchanger HTU can in particular be kept very flat with regard to its vertical extent perpendicular to the laying plane of the windings of the pipe string, which is advantageous for utilising the installation space, e.g. when it is accommodated in particular at least almost horizontally in the device base 12, where only little installation space is available in terms of height.
[0058] In general, the flat structure 32 can be formed either two-dimensionally (e.g., as a flat geometric shape) or three-dimensionally (e.g., as the boundary surface of a three-dimensional body), depending on the available installation space. According to an advantageous embodiment, it consists of straight pipe sections 29 and—possibly differently—curved pipe sections 30 of a preferably meandering pipe string formed by casting, overmolding, or soldering the line section 27 through which flushing fluid 24 flows or through which it flows and the at least one line section 21 running parallel thereto, through which the working medium 17 flows or through which it flows, using a heat-conducting material 28. Practically all radii for the pipe sections 30 and lengths for the pipe sections 29 and 30 are possible, so that the resulting shape of the structure 32 is almost arbitrary.Overall, the given surface area of the structure 32 is utilized as extensively as possible by the pipe parts or pipe sections 29, 30 of the pipe string. In this exemplary embodiment, in particular, only a few open spaces 34 remain laterally between the pipe parts 29 and 30 within the given surface geometry. Due to its curved pipe parts or pipe sections 30, the pipe string can run in a meandering manner overall in order to utilize the available installation space as optimally as possible while still having a total length of several meters. Thus, a flat structure 32 formed by meanders of the heat exchanger HTU formed between the condenser 18 and the heat transfer line section WT is formed overall with a low overall height if the meandering turns of the pipe string run in an at least approximately horizontal plane.In particular, it can be arranged in an at least approximately horizontal plane, preferably in the base support 12 of the dishwasher below the bottom wall of its washing container, where it then requires only minimal vertical space. As mentioned, the surface of the heat exchanger HTU can also be curved, angled, or shaped differently in three dimensions, depending on the available installation space in the dishwasher 1. It is also possible to arrange the heat exchanger HTU, formed between the condenser 18 and the heat transfer line section WT, directly above the evaporator 20 or the compressor 16.
[0059] The flat structure 32 of the heat exchanger WTU can, in the installed position, preferably be arranged close below the rinsing tank 2, in particular in an at least approximately horizontal position. The vertical extension can be small, limited to a few centimeters. In particular, the flat structure of the condenser 18 shown in Figures 3 to 5 has a maximum vertical extension of five centimeters. Other installation positions are of course also possible. Within the aforementioned pipe sections 29, 30 of the meandering pipe string, the casting or overmolding compound or soldering compound 28 connecting the line sections holds the mutually facing surfaces of the adjacent line sections 21 for the working medium 17 on the one hand and for the rinsing liquor 24 on the other hand at a distance 33 measured transversely to their longitudinal extension (see, for example, figure) of less than ten millimeters, so that they are located as close to one another as possible for heat transfer.A significantly smaller distance is also possible. In each pipe section 28, 29, a line section 27 for rinsing solution 24 and at least one line section 21 for working medium 17 are located closely adjacent in cross-section.
[0060] There are various options for the potting or overmolding compound or soldering compound 28 connecting the conductor areas 21 and 27. Cast aluminum has been shown to be a very suitable material due to its excellent thermal conductivity. Alternatively, die-cast zinc or other materials with good thermal conductivity can also be considered. Tin or silver solder can be used as the soldering compound.
[0061] The cast, overmolded, or soldered at least one line section 21 for the working medium 17 of the heat pump 14 is advantageously formed as a copper line, preferably continuously throughout the entire heat pump 14, so that uneven material transitions are avoided. The heat pump 14 can thus be conveniently filled with the working medium and tested before installation in the dishwasher 1. The connections of the circuit for the working medium 17, frequently also referred to as the coolant, do not cross the circuit of the wash liquor 24 at any point and do not come into contact with the wash liquor 24 at any point. This also results in advantages in the selection of materials.
[0062] In contrast, the cast or over-molded or soldered at least one line region 27 for rinsing liquor is preferably designed as a stainless steel line and can be heated up well therein when the heat pump 24 is running.
[0063] In the embodiment of Figures 3-6, the line section 27 for the rinsing liquid 24 is arranged, in particular, centrally between two line sections 21 for the working medium 17 in an at least approximately vertical plane. A first line section 21 for the working medium 17 is located above the line section 27 for the rinsing liquid 24, and a second line section 21 for the working medium 17 is located below the line section 27 for the rinsing liquid. Where the connection 22' for the supply line 22 and the connection 23' for the discharge line 23 of the bypass circuit BK for the rinsing liquid 24 are located next to one another, the line section 21 for the working medium 17 can preferably alternate from top to bottom or from bottom to top.Here, in the embodiment of Figures 3 - 6, the line area 21 for working medium 17 is located, for example, above the line area 27 for flushing liquid 24 for its first pass through the pipe string and below the line area 27 for flushing liquid 24 for its second pass through the pipe string.
[0064] In Figure 6, in a section transverse to the longitudinal course of the pipe string of the heat exchanger HTU, it is shown that within the casting or injection compound or connected to one another by soldering compound, a parallel line region 21 for working medium 17 is assigned to the central line region 27 for rinsing liquor 24 above and below, so that in the cross section three line regions are adjacent to one another.
[0065] Here it is shown that a line region 27 for rinsing liquor 24 is arranged centrally between two line regions 21 for working medium 17 in the planar structure 32 perpendicular to its surface extension, which in Figures 3 - 6 is preferably at least approximately horizontal, one above the other.
[0066] In the embodiment shown in Figure 6, the line section 27 for the rinsing solution 24 is enclosed by two line sections 21 for the working medium 17, which are located opposite each other, so that the line section 27 can be exposed to heat between them and from two sides during operation. Since the line sections 27 on the one hand and 21 on the other hand are parallel to each other, these conditions are the same throughout the HTU heat exchanger.
[0067] In Figure 6 it is also clearly visible that the line region 27 for rinsing liquor 24 has a larger cross-sectional extent than the or here each of the two line regions 21 for working medium 17. Here, in the casting or injection compound or soldering compound 28, two parallel line regions 21 for working medium 17 are assigned to each line region 27 for rinsing liquor 24 at each point, so that in cross-section three line regions 21, 27, 21 are adjacent to one another.
[0068] It is further shown that the line area 27 for rinsing liquor 24 and / or the or each adjacent line area 21 for working medium 17 are flat oval in cross section.
[0069] The long axes 35 of each oval are parallel to each other. Since the three conduit sections 21, 27, and 21 are superimposed, the long axes 35 are arranged horizontally within the planar structure, thus following the planar extension of the planar structure 32. The pipe string formed by the mass 28 with the pipe sections 29, 30 can nevertheless have a round cross-section. The oval shape of the conduit sections enables somewhat better heat transfer, since their directly opposite heat transfer surfaces are then larger than with purely round pipes.
[0070] The flow direction in the line sections 27 for rinsing liquor 24 on the one hand and the or each line section 21 for working medium 17 work here in the countercurrent principle to optimize the efficiency of the heat transfer.
[0071] Alternatively, it would also be possible for a line region 27 for rinsing liquor 24 to be arranged centrally between two line regions 21 for working medium 17 in the planar structure 32, along its surface extension, which is preferably at least approximately horizontal in Figures 3-6 (not shown here). Instead of the layering of the line regions 21, 27 in an at least approximately vertical plane shown in Figures 3-6, it may therefore be expedient if they are arranged next to one another, in particular, in an at least approximately horizontal plane.
[0072] If necessary, it may also be sufficient if, in the pipe string of the HTU heat exchanger, only a single line section 21 for working medium 17, running parallel to the line section 27 for flushing fluid 24, is assigned to it. These two line sections 21, 27 can preferably be arranged in a plane perpendicular to the surface extension of the structure 32 or in a plane parallel to the surface extension of the structure 32.
[0073] Furthermore, it is possible for the flat structure 32 to be inclined and / or shaped in its installed position in the dishwasher 1 such that the line section for washing liquid contained therein drains automatically in a pressureless circuit. This ensures that no washing liquid remains in the line section after the wash cycle; the risk of substances fouling in the line section through which washing liquid flows or the risk of soiling being transferred to the washware in the next wash cycle is minimized.
[0074] For the BK circuit of the wash liquor 24 in the heat pump 14, only a portion of the total volume flow is diverted from the hydraulic circuit HK. The withdrawal point for the wash liquor 24 can be provided within the circulation pump UP, as in the exemplary embodiment of Figure 2, or, in a variation thereof, preferably downstream of the circulation pump UP and upstream of the water diverter WS of the hydraulic circuit HK, or at the water diverter WS itself. The bypass flow thus obtained in the bypass circuit BK preferably has a volume flow of 4 to 8 liters per minute. Due to this design, only a small portion of the wash liquor 24 circulates through the heat exchanger line section WT. In particular, the water volume in the heat exchanger line section WT is relatively small (preferably less than 100 ml). This ensures that the water consumption of the dishwasher according to the invention is only insignificantly higher than that of a conventional dishwasher 1 without a heat pump 14.In addition, the rinse water valve (VA) can be used to switch the bypass (BK) on or off, which allows the circulation (required water volume) for the circulation pump (HK) to be minimized in unheated water baths. A low circulation volume always also means low energy consumption.
[0075] The achieved low water consumption represents a particular advantage of the invention. The wash liquor circuit HK is not disrupted by the heat exchanger HTU, which leads to improved efficiency in the dishwasher hydraulics. The heat pump 14 can be pre-assembled, filled with working fluid 17, and tested for leaks before installation in the dishwasher. The heat pump 14, at least with its essential components 16, 18, 19, 20, is mechanically fixed to a supporting unit 15, forming a modular unit. Any temperature and / or humidity sensors can also be part of this module.
[0076] Finally, Figure 7 illustrates in a schematic plan view that the pipe string, which contains the at least one line section 27 for flushing liquid 24 and the at least one line section 21 for working medium running parallel to it by casting, overmolding, or soldering using a heat-conducting material, can optionally also be laid in a spiral shape to form a flat structure. Spiral means in particular that the pipe string winds around an imaginary center of the flat structure with a distance from the center decreasing from the outside to the inside and / or increasing from the inside to the outside. The windings can preferably run in a helical curve shape or, as in Figure 7, in particular also run in a rectangular, preferably square, curve shape.In spiral installation, the pipe string is guided from the edge of the installation area of the flat structure evenly in spiral circles or rectangles to the center of the room. In particular, a double installation distance is maintained between the turns. After reaching the center of the flat structure, the pipe string is guided back in a preferably S-shaped loop in the same shape within the installed pipe sections. This ensures that the supply and return lines of the pipe string are positioned side by side within the area, ensuring even heating of the entire area occupied by the flat structure.
[0077] This double installation with supply and return lines of the pipe string can also be advantageous in the meandering installation method.
Claims
Patent claims 1. Dishwasher (1), in particular a household dishwasher, with at least one heat pump (14) comprising at least one compressor (16), a condenser (18), an expansion element (19), and an evaporator (20), which are connected to one another via line regions (21) for conveying a working medium (17) that changes its state of aggregation during operation, wherein the heat pump (14) is assigned at least one supply line (22) and one discharge line (23) for washing liquid (24) to be heated, in particular circulated, in the dishwasher (1), characterized in that for heat transfer to the washing liquid (24), at least one line region (27) is provided for the latter, which runs parallel to at least one line region (21) for the working medium (17) of the heat pump (14), wherein both line regions (21, 27) are cast, overmolded, or soldered to one another via a heat-conducting material (28).
2. Dishwasher (1) according to claim 1, characterized in that the casting or overmolding compound or soldering compound (28) connecting the line regions (21, 27) fulfills both a thermally conductive function and a function of mechanically holding the line regions (21, 27) together.
3. Dishwasher (1) according to one of claims 1 or 2, characterized in that the casting or overmolding compound or soldering compound (28) connecting the line regions (21, 27) holds adjacent line regions (21, 27) at a distance (33) of less than ten millimeters, measured transversely to their course.
4. Dishwasher (1) according to at least one of claims 1 to 3, characterized in that that the casting or overmolding compound (28) connecting the line areas (21, 27) is formed by aluminum casting or zinc die casting.
5. Dishwasher (1) according to at least one of claims 1 to 3, characterized in that the soldering mass (28) connecting the line regions (21, 27) is formed by tin or silver solder.
6. Dishwasher (1) according to at least one of claims 1 to 5, characterized in that the line regions (21, 27) which are cast, overmolded or soldered to one another, in particular to form a common pipe string, form pipe parts (29, 30) which run in sections in a straight line or in a curved line, in the interior of which at least one section of the line region (27) for the washing liquid (24) and at least one section of a line region (21) for the working medium (17) are guided parallel to one another.
7. Dishwasher (1) according to at least one of claims 1 to 6, characterized in that the cast or overmolded or soldered at least one line region (21) for the working medium (17) of the heat pump (14) is designed as a copper line.
8. Dishwasher (1) according to at least one of claims 1 to 7, characterized in that the cast or overmolded or soldered at least one line region (27) for the washing liquid (24) is designed as a stainless steel line.
9. Dishwasher (1) according to at least one of claims 1 to 8, characterized in that the cast or overmolded or soldered area forms a heat exchanger (HTU) between the condenser (18) of the heat pump (14) and a heat transfer line section (WT) through which the rinsing liquid (24) can flow or through which it flows.
10. Dishwasher (1) according to at least one of claims 1 to 9, characterized in that the line regions (21, 27) cast or overmolded or soldered together form a common pipe string which runs in a meandering or spiral manner.
11. Dishwasher (1) according to at least one of claims 1 to 10, characterized in that the line regions (21, 27) cast or overmolded or soldered together each have a total length of several meters.
12. Dishwasher (1) according to at least one of claims 1 to 11, characterized in that a single line region (27) for the rinsing liquid (24) and two parallel line regions (21) for the working medium (17) are arranged in the casting or injection molding compound or soldering compound (28), so that in cross section three line regions (21, 27, 21) are adjacent to one another, in particular the line region (27) for the rinsing liquid (24) is located between the two line regions (21) for the working medium (17).
13. Dishwasher (1) according to at least one of claims 1 to 12, characterized in that the line regions (21, 27) cast or overmolded or soldered together result in a flat structure (32) of low overall height formed by meanders or spiral windings.
14. Dishwasher (1) according to claim 13, characterized in that the flat structure (32) is arranged just below the washing container (2).
15. Dishwasher (1) according to one of claims 13 or 14, characterized in that the flat structure (32) has a maximum height extension of five centimeters.
16. Dishwasher (1) according to at least one of claims 13 to 15, characterized in that the flat structure (32) is inclined and / or shaped such that the at least one line region (27) contained therein for the washing liquid (24) drains automatically in a pressureless circuit.
17. Dishwasher (1) according to at least one of claims 13 to 16, characterized in that at least one line region (27) for the rinsing liquid (24) and one or more line regions (21) for working medium (17) are arranged one above the other in the flat structure (32), in particular in an at least approximately vertical plane.
18. Dishwasher (1) according to at least one of claims 13 to 16, characterized in that at least one line region (27) for the rinsing liquid (24) and one or more line regions (21) for working medium (17) are arranged next to one another in the flat structure (32), in particular in an at least approximately horizontal plane.
19. Dishwasher (1) according to at least one of claims 1 to 18, characterized in that the line region (27) for the rinsing liquid (24) has a larger cross-sectional extent than the or each line region (21) for working medium (17).
20. Dishwasher (1) according to at least one of the preceding claims, characterized in that the at least one line region (27) for the rinsing liquid (24) and / or the or each adjacent line region (21) for the working medium (17) are flat oval in cross-section.
21. Dishwasher (1) according to claim 20, characterized in that the long axes (35) of the respective oval are parallel to each other.
22. Dishwasher (1) according to at least one of the preceding claims, characterized in that the at least one line region (27) for the rinsing liquid (24) and the or each line region (21) for the working medium (17) operate according to the countercurrent principle.