Room air conditioner with thermoelectric heat pump

Abstract

The invention relates to a room air conditioner with a thermoelectric heat pump. The thermoelectric heat pump comprises an output plate and an input plate. The at least one sensor is used for sensing a measured object aiming at cooling or heating requirements; and a controller that generates an output based on the sensor output and the at least one setpoint and sets thermoelectric heat pump performance according to the output thereof. The outdoor heat exchanger is connected to the input plate in a heat removal mode, and the indoor heat exchanger is connected to the output plate in a heat mode and provided with an air flowing path for indoor air. In operation, a straight path through the indoor heat exchanger in line with a main air flow towards it contributes less than 44% to its windward area, at least in a single communication region on the indoor heat exchanger that spans more than half of the windward area of the indoor heat exchanger, and behind the area, the indoor heat exchanger extends to a position where it is thermally connected to the output plate. At least some of the air flow paths through the indoor heat exchanger do not include such straight-through paths.

Description

Technical Field

[0001] The invention relates to at least one thermoelectric heat pump and at least one thermally connected heat exchanger. Background Art

[0002] WO2018 / 077321 describes a structure for influencing the temperature of a solid object, such as a vehicle battery, a fluid container, or a microprocessor. Some structures include a thermoelectric heat pump, which is thermally connected to the solid object at one of the two contact plates of the thermoelectric heat pump, so that the plate outputs heat or cold. On its opposite side, at the input plate, the thermoelectric heat pump is thermally connected to a heat exchanger having an air flow path passing through it. The heat exchanger disperses waste cold or waste heat in the surrounding air based on the needs of the object, rather than according to the needs of, for example, room air conditioning. If a closed-loop control is added, the sensor will sense the object temperature, rather than the object being measured for the room air cooling demand or the room air heating demand, such as room air temperature, external temperature, daylight, dew point, volatile organic components, or occupancy.

[0003] Likewise, the initial drawings in WO2018 / 077321 show a thermoelectric heat pump and a porous heat exchanger with straight paths through it in all directions on the top. These straight paths cover more than half of the corresponding frontal area (frontalarea). It is not possible to determine where the air will be expected to flow to the heat exchanger as expected in operation, depending on the shape and temperature of the solid objects and other nearby objects, the orientation of the structure, and the presence of fans.

[0004] The same is true for the figures in WO2018 / 077321, which show cooling tubes above a heat exchanger on top of a thermoelectric heat pump. Furthermore, if this orientation of the structure is assumed, and assuming that the structure is only meaningful for cooling thermally connected objects, the cooling tubes will slow down the rising hot air in the heat exchanger or even cause it to descend, making the airflow towards the heat exchanger chaotic, slow and unstable. A heat exchanger that is not designed to be regularly exposed to the main airflow in intended operation is not configured to exchange heat.

[0005] Some structures such as those depicted in WO2018 / 077321 are irregularly printed heat exchangers that work without a thermoelectric heat pump. Their chaotic air flow paths appear to include large straight paths, but frontal area estimation is impossible due to the lack of detail and distinguishable background. In any case, the main airflow (if present) is probably not aligned with the viewing angle.

[0006] The device of the present invention is a room air conditioner, which includes: at least one thermoelectric heat pump, which includes an output plate and an input plate; and at least one indoor heat exchanger, which is thermally connected to the output plate and is configured to exchange heat with indoor air in the intended operation.

[0007] Suitable thermoelectric heat pumps are commercially available in various designs. Examples of their construction are described, for example, in US 2005 / 0016575 A1.

[0008] Such room air controllers are described in US2013 / 0319014A1. Each indoor heat exchanger is formed by fins on the output plate of a thermoelectric heat pump. These fins are designated as components of metal sheets, ribs, fingers, etc. They are shown in the figure as being freestanding within the air channel and therefore do not form a wall around the path for air to flow through the indoor heat exchanger. In particular, there is no air flow path that is at an angle to the main air flow towards the indoor heat exchanger as expected in operation.

[0009] The indoor heat exchanger of the room air conditioner according to the present invention has an air flow path therethrough.

[0010] US2017 / 0363307A1 describes a room air conditioner with a thermoelectric heat pump that pumps heat between flat plates on either side. In operation, as expected, a centrally mounted fan brings in air from the room and pushes it radially toward an indoor heat exchanger. The latter consists of flat metal plates arranged side by side in a semicircle around the fan, contacting the housing of the room air conditioner at its sides; and vertical thermosyphons that hold the metal plates together and also provide a thermal connection to the output plate of the thermoelectric heat pump. Between the metal plates and the thermosyphons, the straight path is consistent with the main airflow toward them. They occupy more than half of the frontal area of ​​the indoor heat exchanger, which means low airflow resistance. Along the flow path of the air passing through it, each curved thermosyphon first protrudes laterally and then retreats, thereby locally changing the cross-sectional area of ​​the air flow path. The thermosyphons between an adjacent pair of metal plates in line with the main airflow also constitute the air flow path walls of the interconnected side channels. The air leaves the indoor heat exchanger downwards back into the room, thus serving as indoor air for cooling the lower portion thereof. The remaining air from the room is urged upwards through a second heat exchanger which is thermally connected to another plate of the thermoelectric heat pump, thereby heating the higher portion of the room.

[0011] The room air conditioner according to the present invention further comprises at least one outdoor heat exchanger which is thermally connected to the input plate of the thermoelectric heat pump and is configured to exchange heat with the outdoor environment during intended operation.

[0012] Such a room air conditioner is indicated in patent application KR2012035308A. With the help of an indoor heat exchanger extending into the inlet air channel, a thermoelectric heat pump can remove heat from the air from the outside or add heat to the air from the outside. An electric fan draws fresh indoor air into the room. The indoor heat exchanger is allegedly a radiator block and appears to be a structure of aligned metal plates that form a straight path in line with the main airflow toward them. Their dominant windward straight path area and the smooth plate surface without lateral protrusions or depressions indicate that they are around the air flow path of a highly laminar airflow with minimal air resistance. A similar outdoor heat exchanger on the other side of the thermoelectric heat pump is located indoors, but extends into the outlet air channel, through which the air from the room is blown to the outdoors, thereby releasing the heat in the air on its way to the outdoor environment, and correspondingly collecting heat therefrom.

[0013] For applications in buildings, ships, cars, etc., where there is a need, for example, to reliably avoid condensation, it is known that thermoelectric cooling is less efficient and effective, and more expensive, than cooling with vapor compression refrigeration. Similar disadvantages exist for thermoelectric heating. Despite some clear advantages, such as decentralized installation, retrofit installation, compactness and low maintenance, this has prevented their widespread use. The object of the present invention is to provide a room air conditioner with thermoelectric cooling or heating that is better suited to the application. Summary of the invention

[0014] According to the present invention, in a simply connected region on the indoor heat exchanger, a straight path through the indoor heat exchanger in line with the main air flow toward them in the intended operation does not exist or contributes less than 44% to the windward area of ​​this region, the corresponding part of the indoor heat exchanger extends to the position where it is thermally connected to the output plate, and the windward area of ​​this region is at least half of the windward area of ​​the indoor heat exchanger. Preferably, in the case of a good structure and material selection of the indoor heat exchanger, such a straight path in this region does not exist or contributes less than 36% to the windward area of ​​this region.

[0015] In operation, the air does flow primarily in a main direction toward the heat exchanger, and then it can be turned on a local scale by flowing around the leading edge of the indoor heat exchanger material itself. If the room air conditioner includes an electric ventilator, the effect of the initial rotational component of the air velocity can usually be ignored, or its effect can be well estimated. The same is true for the effect of standing sound waves in the air channel. Alternatively, in the absence of a ventilator or inclined walls nearby, the main airflow direction toward the indoor heat exchanger is in the vertical direction because the air density changes when the air is cooled or heated therein. Occasional interference with other air flows in the room may cause temporary reductions in effect or efficiency, but are negligible for the purposes of the present invention.

[0016] The invention is based on the recognition that, when the airflow into or within the indoor heat exchanger of a room air conditioner is disturbed by reducing the frontal area of ​​the straight paths through it, the heat exchange with it is improved disproportionately, thereby also generally improving the thermal conductivity within the indoor heat exchanger, while the airflow through the indoor heat exchanger can be kept at an acceptable level. This allows meeting the commercial requirements for a wider application of room air conditioners, including practical upper limits on production costs and size. Instead of the entire indoor heat exchanger, a single-connected area thereon is sufficient if it is large enough and if the corresponding part of the indoor heat exchanger extends to the position where it is thermally connected to the output plate of the thermoelectric heat pump, that is, the part behind said area in the main direction of the incoming airflow. The indoor heat exchanger parts with wider or more densely placed straight paths can be made in line with the incoming airflow close to this area, provided that they do not hinder the conduction of heat within the heat exchanger to the position where it is thermally connected to the output plate, for example at the edge of the indoor heat exchanger. These additional indoor heat exchanger sections can significantly increase the average frontal area contribution of the straight airflow path, the primary limitation being the size of the room air conditioner, while still providing the benefits of the present invention with the indoor heat exchanger in the above area.

[0017] According to the present invention, there is an air flow path through the indoor heat exchanger that does not include such a straight passage.

[0018] The other air flow paths preferably extend through corresponding portions of the indoor heat exchanger.

[0019] Along most of the air flow path through the indoor heat exchanger, preferably through the corresponding part of the indoor heat exchanger, the path wall advantageously changes the air flow path cross-sectional area locally by more than 2% of the previous air flow path cross-sectional area at least 20 times by lateral protrusion or retreat, preferably at least protruding or retreating at least 80 microns at some place. The opening for air between the protruding path walls has a typical diameter of at most 4mm. Advantageously, the surface of the indoor heat exchanger, preferably the surface of its corresponding part, is uneven on at least 40% of its area. The uneven surface is not flat, but curved, or is rough at a scale as low as at least 80 microns, or between the two. The airflow resistance is hardly affected by it.

[0020] Advantageously, in the expected operation, the cross-sectional area of ​​the indoor heat exchanger that is in line with the main air flow of its leading edge at a shared distance from the position of the output plate where the indoor heat exchanger is thermally connected to the thermoelectric heat pump gradually decreases with the increase of distance, preferably making the internal temperature gradient size similar everywhere, to within half of its average value in dynamic equilibrium. If each point where the indoor heat exchanger is thermally connected to the output plate has the same minimum distance, the leading edge of the indoor heat exchanger is at a common distance. Some fluctuations in cross-sectional area may occur, such as when the elongated portions that are almost parallel in the periodic indoor heat exchanger structure intersect quickly. Even so, the internal temperature gradient of the indoor heat exchanger can still be made low and stable in the expected operation. Therefore, the indoor heat exchanger can have a larger size without unacceptable efficiency loss at its far end, or condensation at its contact output plate, or efficiency loss caused by excessive temperature difference between the thermoelectric heat pump plates.

[0021] In one embodiment, if the distance from the position where the indoor heat exchanger is thermally connected to the output plate increases, the ratio of the average cross-sectional area of ​​the indoor heat exchanger to the average cross-sectional area of ​​its material decreases. This can be achieved by providing the indoor heat exchanger with a smaller material portion per unit volume, or providing it with a thinner material portion per unit volume. However, it is advantageous that the shape of the indoor heat exchanger tapers away from the position where it is thermally connected to the output plate of the thermoelectric heat pump. Then, as the distance increases, the envelopes of these sections will approach each other, which has a similar effect even if the contents of the indoor heat exchanger are homogeneous. Its shape is preferably substantially horizontally tapered in the expected operation. The flat thermoelectric heat pump is best positioned parallel to the outer wall of the room where the room air conditioner is installed, and the indoor heat exchanger is directly held against it. Thus, from the side, the indoor heat exchanger, for example, resembles a pointed capital letter "L". If the output plate of the thermoelectric heat pump extends horizontally in operation, the indoor heat exchanger may resemble a discus suspended above the thermoelectric heat pump.

[0022] The techniques in powder metallurgy and additive manufacturing allow such indoor heat exchangers to be produced accurately and cost-effectively. They may contain metals or alloys, preferably alloys with high aluminum content. They may be formed into a network of interconnected strips, such as a tree-shaped network or a mesh network, such as a porous metal foam, or more precisely into a folded sheet structure, especially with a near-minimum surface. They may be quasi-chaotic or periodic. They may be made hollow enough for air to flow through. They may be appropriately shaped so as to exchange heat with the air. They may be made solid enough so as to conduct heat therein. The indoor heat exchanger of the room air conditioner according to the present invention may also be produced using less precise techniques, such as sintering preformed thermally conductive ceramic parts, most likely aluminum nitride composite materials, or alloy parts.

[0023] The indoor heat exchanger advantageously includes an insulating surface cover at least adjacent to where it is thermally connected to the output plate of the thermoelectric heat pump. Preferably, any heat conduits between the indoor heat exchanger and the output plate of the thermoelectric heat pump also include a cover, as well as the output plate itself where it is not in contact with either. The insulating surface cover may contain one or more polymeric materials.

[0024] Advantageously, the room air conditioner comprises at least one indoor heat exchanger holder, which is reversibly configured to hold the indoor heat exchanger, preferably against the output plate of the thermoelectric heat pump. The indoor heat exchanger holder may be a fixture made of wire surrounding the indoor heat exchanger, or one of a plurality of flange round head screws and a material with threaded holes that can interact with it. These measures allow the indoor heat exchanger to be easily removed for cleaning or replacement. Preferably, the room air conditioner also includes an actuator, which is configured to move the indoor heat exchanger holder so as to increase the heat exchange with the indoor air. Preferably, the room air conditioner is configured to expose the air from the room to the indoor heat exchanger, rather than, for example, enclosing the indoor heat exchanger in the inlet air channel and only drawing air from the outside in the room during operation.

[0025] The outdoor heat exchanger can usually be made larger than the indoor heat exchanger by being thermally connected at the other side of the thermoelectric heat pump. Usually, it can be placed out of sight, if appropriate, by connecting it to the input plate via a heat pipe, which is preferably a passive heat pipe, such as a thermosyphon or a heat pipe. It can be ventilated outdoors, and noise is less considered. However, especially if the outdoor heat exchanger is configured to transfer heat to or from the air, it preferably includes a structure for an indoor heat exchanger as described herein. Alternatively, it can be a liquid flow channel that is in close contact with at least a portion of the input plate or even supplemented by at least a portion of the input plate. Although such an outdoor heat exchanger may be located indoors, the flow will release heat or cold in the outdoor environment. For example, a metal box against the input plate, preferably with thermally conductive paste therebetween, includes a connector for a pipe filled with cold water and a connector for a pipe that guides heated water to an outdoor drain.

[0026] The aforementioned structural measures solve the problem of a relatively small room air conditioner with a thermoelectric heat pump, which achieves improved performance and economy while still minimizing condensation during cooling, odors during heating and undue maintenance work.

[0027] According to the present invention, a room air conditioner includes: at least one sensor, which is configured to sense a measured object for cooling demand; and a controller, which is configured to generate an output based on the sensor output and based on at least one set point, and is configured to set the performance of a thermoelectric heat pump according to its output.

[0028] Examples of measured objects are changes in passive infrared radiation caused by human movement in the room, lighting levels in a windowless room, or other things that indicate occupancy. Preferably, the measured object indicates air temperature, for example by means of a temperature sensitive resistor, an electromagnetic radiation sensitive semiconductor junction, or an acoustic wave sensitive piezoelectric substrate. Heating or cooling is usually triggered by a sensor of the air temperature outside the building. However, more preferably, alternatively or preferably additionally, the measured object indicates the temperature of the air in the room. Ideally, the room air conditioner also includes a sensor for the internal air humidity, such as a dew point sensor. Air humidity itself is not a measured object for cooling or heating requirements, but it becomes a measured object if combined with the room air temperature.

[0029] The sensor and controller may be integrated into the body of the room air conditioner, but a portion of either may be remote. If so, the sensor or controller comprises a module in the body of the room air conditioner that is configured to receive data and act accordingly. For example, the control software runs on a dedicated server or a cloud server. Thus, the controller comprises a module in the body of the room air conditioner that is configured to receive control data and set the performance of the thermoelectric heat pump accordingly. In addition, the controller may perform short-term control locally and perform remote analysis to optimize the short-term control, in particular to infer whether relevant operating conditions have changed, or to adjust the control if it knows that they have changed. Preferably, the controller is configured to determine a need or receive a request for user feedback, and is configured to ask for feedback from the user. Preferably, it is configured to register the user's electronic device, and is configured to ask for feedback by means of the device, such as by presenting a questionnaire or by using a large language model.

[0030] The controller sets the performance of the thermoelectric heat pump, for example by determining its electrical power intake. It may regulate the thermoelectric heat pump in closed loop in any manner, for example in a two-point manner by switching the thermoelectric heat pump on and off, or for example in a continuous or near-continuous modulation in response to a proportional, integral or differential difference between a processed sensor output and a set point. However, advantageously, rather than regulating only in order to limit the temperature difference between the output plate and the input plate of the thermoelectric heat pump, the controller is sometimes configured to modify its output, in particular with the aim of limiting this temperature difference to a maximum value below 35°C, in order to remain in the most efficient performance range of the thermoelectric heat pump.

[0031] Likewise, the controller is advantageously configured to modify its output from time to time, compared to adjusting only to limit condensation at the output plate of the thermoelectric heat pump or condensation on the indoor heat exchanger. Advantageously, it is configured to calculate the performance of the thermoelectric heat pump where condensation occurs. This calculation may require an additional humidity sensor or dew point sensor, frequent reception of weather data, or initial thermodynamic modeling specific to the room. In this way, the indoor heat exchanger can be close to the dew point temperature without unacceptably crossing the temperature. Advantageously, the controller is particularly sometimes configured not to cause the thermoelectric heat pump to cool the output plate, even if the sensor output and set point will require this. Advantageously, the controller is even sometimes configured to modify its output so as to temporarily heat the output plate to a minimum value above 60°C. In order to disinfect the indoor heat exchanger, the average output plate temperature is preferably maintained above 70°C for a period of time, such as for 30s, so as to keep maintenance from occurring frequently.

[0032] For thermoelectric room air conditioners having an indoor heat exchanger with little or no straight path therethrough in line with the main inlet air flow, these control measures require some computational effort but allow for optimization of performance and economy or reduction of maintenance while still preventing condensation and odor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is illustrated in the following figures.

[0034] Figure 1 A sketch is shown of the main body of a room air conditioner according to the present invention.

[0035] Figure 2 A schematic side view of components in a portion of the body of the same room air conditioner is shown.

[0036] Figure 3 Sketches showing rectangular cut-outs of indoor heat exchangers of the same or different room air conditioners.

[0037] Figure 4 Sketch of a rectangular cut-out of a variant indoor heat exchanger of a similar room air conditioner according to the present invention is shown close to its thermal connection location.

[0038] Figure 5 A sketch of a rectangular cut-out of the same variant indoor heat exchanger is shown away from its thermal connection location. DETAILED DESCRIPTION

[0039] exist Figure 1 In the embodiment of the invention, the main body of the air conditioner for human habitation rooms comprises a housing 1. It is intended to be installed in an opening in the paneling to the left of a room window or in the opening of an air handling duct or in an opening in an outer wall, the main purpose being to cool preferably at a high point in the room. An upright cover plate 2 measuring 22 cm by 22 cm should close the opening.

[0040] The indoor heat exchanger 3, lacking structural details here, is intended to be placed in a room. No fixed objects hinder the free flow of air in the room towards or away from it. It is held against the flat output plates of the thermoelectric heat pump, which are flush mounted in large gaps in the cover plate 2, neither of which is shown here. Preferably, thermally conductive paste surrounds the material of the indoor heat exchanger 3 where it contacts the output plates of the thermoelectric heat pump. The clamp holding the indoor heat exchanger 3 consists of thin rods 4, 5 and spring-loaded hinges for them, which are hidden inside the housing 1.

[0041] The indoor heat exchanger 3 is adjacent to the output plates on one side and tapers horizontally away from them on the other side. In operation, the beak-like protrusion can capture a larger vertical air flow, which reaches a practical size due to the optimization of its shape. For aesthetic reasons, and assuming that there is some free space on either side of the room air conditioner body, the horizontally tapered beak of the indoor heat exchanger can alternatively be rounded around the vertical direction so that it resembles a half disk.

[0042] When the room air conditioner cools the air approaching from above, the leading edge of the indoor heat exchanger 3 at the top, which is at a certain distance from the output plate of the thermoelectric heat pump, constructs an almost straight surface line parallel to the rod 4. The area of ​​the vertical section along this line decreases with each increase of their common distance away from the output plate. The reduction is only selected so that in dynamic equilibrium, given the contents of the indoor heat exchanger 3, assuming that the approaching air has a uniform temperature, the size of the internal temperature gradient on the width of the indoor heat exchanger 3 in operation is very small. The small linear variation of temperature everywhere in the indoor heat exchanger 3 allows its large horizontal extension without unacceptable efficiency losses caused by overworking the thermoelectric heat pump, or unacceptable condensation at the place where its output plate contacts the indoor heat exchanger 3, or unacceptable efficacy losses at the far end of the tapered portion.

[0043] The sensor package 6 inside and behind the cover plate 2 senses both temperature and humidity locally close to the cooling plate of the thermoelectric heat pump but upstream during cooling operation. Therefore, this location is very suitable for dew point measurement and very well suited for indoor air temperature measurement during cooling. The sensor package 6 also includes a temperature sensor that can measure the temperature at a distance as an indication of the general air temperature in the room.

[0044] The outdoor heat exchanger, intended to be placed outside the room, is thermally connected to the input plate at the rear side of the thermoelectric heat pump by means of heat pipes in arms 7. The outdoor heat exchanger 8 is larger than the indoor heat exchanger 3. It is located away from any window next to which the room air conditioner body is mounted, and further to its left so as not to obstruct the view from inside the room too much.

[0045] If the room air conditioner is cooling the room, at the rear of the heat pipe arm 7, on its shady side and away from the heated air flow originating from the outdoor heat exchanger 8, an air temperature sensor 9 is mounted for measuring the air temperature outside the room.

[0046] Figure 2 Schematically shows a part of the main body of the room air conditioner, among other devices. On the left side, the indoor heat exchanger 3 has been cut in the middle. On the right side, the arm 7 is also cut.

[0047] Inside the housing 1 , the thermoelectric heat pumps 10 are Peltier elements “CP30338” of the company CUIDevices arranged in a four by four matrix. Their output plates 11 are flush with the cover plate 2 . Their input plates 12 are connected to the heat pipes 13 .

[0048] The wireless communication module 14 can receive room air temperature data from a separate air temperature sensor 15 installed in the room away from the main body of the room air conditioner and away from the indoor air circulation through the indoor heat exchanger. The use of this sensor 15 improves the determination of whether cooling or heating efforts must be extended. The communication module 14 relays the sensed data to the lower level controller portion 16 in the housing 1.

[0049] By setting the performance of the thermoelectric heat pump 10, the lower controller part 16 performs closed-loop regulation based on room temperature data from the separate air temperature sensor 15 and the sensor set 6, based on humidity data from the sensor set 6 and based on external temperature data from the air temperature sensor 9. This combination of measured objects is used to determine the cooling or heating demand. However, if necessary, the lower controller part 16 modifies its output to limit the temperature difference between the output plate 11 and the input plate 12 to 30°C. In addition, if necessary, it also modifies its output to limit condensation on the output plate 11 of the thermoelectric heat pump 10 or on the indoor heat exchanger 3, which is only partially depicted here. In both cases, it causes the thermoelectric heat pump 10 to cool its output plate 11 less than required or not cool at all, even if the sensor output and the set point would require it to do so. Once a week, the lower controller part 16 modifies its output so that the output plate is heated at 80°C for 20s.

[0050] The set point for closed-loop regulation is determined by the upper controller part 17, which takes into account the identity of the occupant (if available). The upper controller part 17 is a cloud server on which dedicated software runs, and it communicates with the lower controller part 16 through the communication module 14. The upper controller part 17 adjusts the algorithm by which the lower controller part 16 calculates the cooling performance of the thermoelectric heat pump 10 in the case where condensation will occur. It also analyzes the power consumption over time and provides various control models to the occupant through an app on his smartphone. It also reminds the occupant of the weekly heating pulse and recommends to ventilate the room briefly. If the upper controller part 17 determines a need or receives a request for user feedback, it asks for feedback with the help of a questionnaire presented by the app.

[0051] Figure 3The structural details of the contents of the indoor heat exchanger 3 of the same or different room air conditioners are presented, which are consistent everywhere. Thus, a single-connected area with a small number of straight passages in line with the main air flow covers the entire top side of the indoor heat exchanger 3. Its counterpart, that is, the part behind this area, is the entire volume of the heat exchanger 3.

[0052] The structure is very similar to a gyroid, with curves everywhere on its surface. It can be produced by established additive manufacturing techniques. The wall thickness is 140 microns. The holes of about 1 mm are identifiably aligned to form four straight passages 18 for air to pass through the indoor heat exchanger 3. Their direction is consistent with the main air flow from the room towards them, in Figure 1 When the room air conditioner cools the air, the main air flow comes from above, and when it heats the air, the main air flow comes from below. Such straight passages contribute 19% of the frontal area of ​​the indoor heat exchanger 3. Flow paths with straight passages in different directions are interconnected, but require the approaching air to turn first. Some of these flow paths are blocked at the far end by the cover plate 2 or the flush-mounted output plate 11 therein. There, the vertical straight passages contribute only 3% of the frontal area.

[0053] Along the air flow paths of these four straight passages 18, the path wall 19 protrudes and retracts laterally 5 times each within the depicted rectangular volume. Each time, the local reduction in the cross-sectional area of ​​the air flow path is estimated to be 80% of the previous cross-sectional area of ​​the air flow path, which covers the large twisted funnel of the hole leading to the straight passage 18. Downstream, for the same reason, the local increase is estimated to be about 500%. The largest lateral protrusion is about 0.7 mm, all the way from the funnel to the funnel of the next parallel straight passage 18 or the funnel of a side channel 20 that branches at a different angle. Such interconnected side channels protrude and retract laterally less frequently within the length of the depicted rectangular volume.

[0054] Figure 4 Structural details of the contents of the indoor heat exchanger of one variant are presented from different angles. In this variant, the structure of the indoor heat exchanger is not consistent. It can only be produced economically through additive manufacturing.

[0055] Its structure is similar to the same gyroid of the same material. However, near the location where the indoor heat exchanger is thermally connected to the output plate of the thermoelectric heat pump, the wall thickness is larger, 180 microns. As a result, local heat conduction within the internal heat exchanger material is improved. Depending on the parameters of other locations, this may allow a straighter shape for the indoor heat exchanger as a whole, but keep the size of the internal temperature gradient small in dynamic equilibrium.

[0056] At the top of the depicted rectangular volume, it is possible to note the beginning of the holes of two straight passages 21 through the indoor heat exchanger, in line with the main air flow coming from the room towards them. At the bottom left, it is possible to see the beginning of the holes of two other straight passages 21. These walls conduct heat from there and from the rest of the indoor heat exchanger, approximately perpendicularly to the four straight passages 21, towards the thermal connection with the output plate of the thermoelectric heat pump, or vice versa.

[0057] Figure 5 Structural details of the contents of the same variant indoor heat exchanger are shown, but the depicted rectangular volume is now located away from where the indoor heat exchanger is thermally connected to the output plate of the thermoelectric heat pump.

[0058] Here, the wall thickness is only 50 microns. Therefore, the four straight paths 21 at the top and bottom of the depicted rectangular volume are much larger, so that now the windward area of ​​the indoor heat exchanger contributes no less than 36%. Therefore, the single-connected area can cover these parts of the indoor heat exchanger. However, for this structure and material, 36% is close to the upper limit, because in fact the heat conduction in the wall of the indoor heat exchanger can roughly keep up to avoid excessively steep temperature drops in thermodynamic equilibrium. In addition, the heat exchange between the air and the path wall will begin to be affected by the reduction of airflow disturbances.

[0059] By comparison Figure 4 and Figure 5 It can be seen that as the distance from the location where the indoor heat exchanger is thermally connected to the output plate increases, the ratio between the average cross-sectional area of ​​the indoor heat exchanger and the average cross-sectional area of ​​its material decreases. This is achieved by Figure 5 The indoor heat exchanger in the embodiment of the present invention is provided with a thinner material portion. Due to the reduced wall thickness, the local heat conduction capacity has deteriorated. In order to achieve similar effects, the depth of the indoor heat exchanger in the direction of the four straight passages 21 of this variant must be greater than Figure 3 The depth of the original indoor heat exchanger in . At the same time, the depth of the indoor heat exchanger near the location where it is thermally connected to the output plate of the thermoelectric heat pump can be much smaller. Due to the optimization of its wall thickness, the shape of this variant indoor heat exchanger can be straight, like a brick or like half a plate, but for a given mass of the thermoelectric heat pump and a given area of ​​its output plate, it can remain very large.

Claims

1. Room air conditioner, including: at least one thermoelectric heat pump (10) comprising an output plate (11) and an input plate (12), at least one indoor heat exchanger (3) having an air flow path (20) therethrough, the indoor heat exchanger (3) being thermally connected to the output plate (11) and being configured to exchange heat with indoor air in intended operation, at least one outdoor heat exchanger (8) thermally connected to the input plate (12) and configured to exchange heat with the outdoor environment during intended operation, It is characterized in that The room air conditioner comprises at least one sensor (6, 9, 15) configured to sense a measured object for cooling or heating demand, The room air conditioner comprises a controller (16, 17) configured to generate an output based on a sensor output and based on at least one set point, and configured to set a performance of the thermoelectric heat pump (10) according to its output, In a single-connection area on the indoor heat exchanger (3), straight paths (18, 21) through the indoor heat exchanger (3) that are in line with the main air flow toward them in intended operation do not exist or contribute less than 44% to the frontal area of ​​the area, The corresponding portion of the indoor heat exchanger (3) extends to the position where it is thermally connected to the output plate (11), The windward area of ​​the region is at least half of the windward area of ​​the indoor heat exchanger (3), and At least some of the air flow paths (20) through the indoor heat exchanger (3) do not include such straight passages (18, 21).

2. A room air conditioner according to the preceding claim, wherein The straight passage (18, 21) does not exist or contributes less than 36% to the windward area of ​​the region.

3. A room air conditioner according to any one of the preceding claims, wherein: Along most of the air flow path through the indoor heat exchanger (3), the path wall (19) causes the air flow path cross-sectional area to be locally changed by more than 2% of the previous air flow path cross-sectional area at least 20 times by lateral projection or retreat.

4. A room air conditioner according to any one of the preceding claims, wherein: The surface of the indoor heat exchanger (3) is uneven over at least 40% of its area.

5. A room air conditioner according to any one of the preceding claims, wherein: In intended operation, the cross-sectional area of ​​the indoor heat exchanger (3) in line with the main air flow towards its leading edge at a common distance from the location where the indoor heat exchanger (3) is thermally connected to the output plate (11) gradually decreases with increasing distance.

6. A room air conditioner according to any one of the preceding claims, wherein: The shape of the indoor heat exchanger (3) tapers away from the location where it is thermally connected to the output plate (11) of the thermoelectric heat pump (10).

7. A room air conditioner according to any one of the preceding claims, wherein: The indoor heat exchanger (3) comprises a heat insulating surface cover at least adjacent to the location where it is thermally connected to the output plate (11) of the thermoelectric heat pump (10).

8. A room air conditioner according to any one of the preceding claims, wherein: The room air conditioner comprises at least one indoor heat exchanger holder (4, 5) which is reversibly configured to hold the indoor heat exchanger (3).

9. A room air conditioner according to any one of the preceding claims, wherein: The sensor (6, 9, 15) or the controller (16, 17) comprises a module (14) in the body of the room air conditioner (1), the module (14) being configured to receive data from a remote part thereof and to take action accordingly.

10. A room air conditioner according to any one of the preceding claims, wherein: The controller (16, 17) is sometimes configured to modify its output to limit the temperature difference between the output plate (11) and the input plate (12) of the thermoelectric heat pump (10).

11. A room air conditioner according to the preceding claim, wherein The modification aims to limit the temperature difference to a maximum value below 35°C.

12. A room air conditioner according to any one of the preceding claims, wherein: The controller (16, 17) is sometimes configured to modify its output for limiting condensation at the output plate (11) of the thermoelectric heat pump (10) or on the indoor heat exchanger (3).

13. A room air conditioner according to the preceding claim, wherein The controller (16, 17) is configured to calculate the performance of the thermoelectric heat pump (10) at which condensation will occur.

14. A room air conditioner according to any one of the preceding claims to claim 12, wherein The controller (16, 17) is sometimes configured to not cause the thermoelectric heat pump (10) to cool the output plate (11) even if the sensor output and the set point would require doing so.

15. A room air conditioner according to any one of the preceding claims, wherein: The controller (16, 17) is sometimes configured to modify its output so as to temporarily heat the output plate (11) to above a minimum value of 60°C.

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