Device for air conditioning a building

Abstract

The invention relates to a method for building air conditioning in which a temperature control medium circulates in a closed loop comprising a heat or cold source and at least one heat exchanger, wherein the temperature control medium undergoes heat exchange with the surroundings in the heat exchanger, wherein the temperature control medium is a hygroscopic liquid, and the heat exchanger is designed to be liquid-tight but permeable to water vapor, and the temperature control medium absorbs or releases water vapor from the surroundings during circulation through the heat exchanger. A corresponding device for building air conditioning is also described.

Description

[0001] The invention relates to a device for building air conditioning with a heat or cold source and at least one arranged heat exchanger and a temperature control medium circulating in a circuit between the heat or cold source and the at least one heat exchanger, wherein a hygroscopic liquid is provided as the temperature control medium and the heat exchanger is designed to be liquid-tight but permeable to water vapor, such that water vapor from the environment of the heat exchanger can be absorbed or released to the environment by means of the temperature control medium via the at least one heat exchanger.

[0002] Such methods and devices are known, for which reference is made, by way of example, to EP 2 474 797 A1. The operating principle of the known methods and devices is based on heating or cooling the temperature control medium as required for heating or cooling the interior of a building via the heat or cold source integrated into the cycle and supplying it to the heat exchanger, which is in a heat exchange relationship with the interior of the building. If the temperature control medium is heated to a higher temperature than the interior of the building, it releases a corresponding heat flow to the interior of the building in the heat exchanger and thus heats it. Conversely, if the temperature control medium is cooled to a lower temperature than the interior of the building, it absorbs a corresponding heat flow from the interior of the building in the heat exchanger, i.e., it extracts heat from the interior, so that a corresponding cooling occurs.

[0003] The known methods and devices thus serve to increase or decrease the temperature of the interior of the building in which the heat exchanger is located, as required, so that appropriate air conditioning of the building can be achieved.

[0004] Other parameters influencing building climate control, particularly humidity or the moisture content of the indoor air, cannot be controlled by known methods and devices; in fact, they are often negatively affected. For example, intensive heating of the building's interior can cause the indoor air to become undesirably dry, meaning the relative humidity drops significantly. Conversely, intensive cooling of the building's interior can also cause the relative humidity to rise due to the falling air temperature, leading to over-humidification of the indoor air, which can ultimately result in mold growth and similar undesirable effects.It is therefore currently unavoidable to influence the humidity of the indoor air, in addition to temperature control, for example by means of regular air exchange, the use of humidifiers and / or dryers.

[0005] From DE 198 16 185 C1, it is known to circulate a temperature-controlled sorbent through a capillary tube system in a planar building element for the air conditioning of rooms, whereby the room air cools at the surface of the capillary tubes and any condensate that forms diffuses through the pores of the capillary tube system and is absorbed by the sorbent. This diffusion is driven by a partial vapor pressure difference between the sorbent and the room air inside the building. Accordingly, constant active temperature control and circulation of the sorbent are necessary for moisture removal, which is energy-inefficient.

[0006] The object of the present invention is to propose a device for building climate control which overcomes the disadvantages of the prior art and ensures energy-efficient building climate control including control of the humidity of the indoor air.

[0007] To solve the problem posed, a device according to the features of claim 1 is proposed according to the invention.

[0008] Advantageous embodiments and further developments of the invention are the subject of the dependent claim.

[0009] A device for building air conditioning of the type mentioned above, proposed within the scope of the invention, comprises at least one heat exchanger arranged in an interior space of a building and a temperature control medium circulating in a circuit between the heat or cold source and the at least one heat exchanger. According to the invention, the temperature control medium is a hygroscopic liquid, in particular a salt solution, and the heat exchanger is designed to be liquid-tight but permeable to water vapor, such that water vapor from the surroundings of the heat exchanger can be absorbed or released to them via the temperature control medium and the at least one heat exchanger.

[0010] According to the invention, the at least one heat exchanger is formed as a climate element with an embedded capillary tube mat, which is formed by two collector tubes with capillary tubes running between them, which can be permeated by the temperature control medium, wherein the walls of the capillary tubes are liquid-tight but water vapor permeable, in order to enable water vapor exchange between the temperature control medium and the interior of the building in addition to heat exchange.

[0011] The invention further provides that the capillary tubes are formed from hollow fibers that are permeable to water vapor but impermeable to liquids. Such hollow fibers are widely known and are currently used, for example, as filters in membrane technology. They have permeable structures in their wall composition, so that the fiber walls act as a membrane. Such hollow fiber membranes consist, for example, of polyethersulfone, polysulfone, or polyacrylonitrile, or of sintered or extruded polytetrafluoroethylene, polypropylene, or polyethylene.

[0012] Within the scope of the invention, such tubular hollow fibers can preferably have a round cross-section, with the diameter preferably being about 0.3 mm to 5 mm.

[0013] The walls of the hollow fibers are preferably semipermeable to water vapor or designed as a reverse osmosis membrane to be selectively permeable only to water vapor molecules. They can also be hydrophobic to prevent condensation of water on the surface of the hollow fibers.

[0014] The climate element with embedded capillary tube mat proposed within the framework of the device according to the invention is designed as a rigid panel for wall or ceiling mounting and has a dimensionally stable support frame, for example made of metal or plastic profiles, which is filled with a porous and water vapor-permeable filler based on diatomaceous earth to form a panel that can have a surface finish matching the rest of the building's interior. The capillary tube mat is embedded within the filler so that it is not visually apparent.

[0015] A hygroscopic liquid is provided as the temperature control medium in the cycle between the heat or cold source and the at least one heat exchanger; that is, a liquid which, in addition to the known ability to be tempered to different temperature levels, is also capable of absorbing or releasing moisture. The hygroscopic liquid provided according to the invention circulates within the cycle through a heat exchanger that is liquid-tight but permeable to water vapor, so that the temperature control medium absorbs or releases water vapor, e.g., from the interior of the building, during its circulation through the heat exchanger, depending on the humidity of the ambient air surrounding the heat exchanger in the interior of the building.

[0016] In this way, it is possible not only to allow heat exchange with the interior of the building in the heat exchanger in the known way by adjusting the temperature of the temperature medium and to use it for temperature control of the interior, but it is also possible to humidify or dehumidify the room air via a material exchange between the heat exchanger and the temperature medium circulating in it and the surrounding room air.

[0017] The absorption of moisture from the environment, e.g., from the room air inside the building, into the hygroscopic temperature control medium, or the release of moisture from the hygroscopic temperature control medium in the heat exchanger to the room air inside the building, is determined by the prevailing difference in partial vapor pressures between the temperature control medium and the room air inside the building. This partial pressure difference causes the transfer of water vapor from the side with the higher partial vapor pressure to the side with the lower partial vapor pressure.

[0018] In order to be able to regulate the partial pressure difference accordingly and thus control and regulate the humidification or dehumidification of the interior of the building, a proposal of the invention provides that the pressure of the temperature control medium circulating in the cycle is regulated, for example by regulating a feed pump for the temperature control medium integrated into the cycle or corresponding throttle valves in the circuit of the temperature control medium.

[0019] The pressure of the temperature control medium in the cycle can be, for example, about 0.5 to 1 MPa, in particular about 0.8 MPa, i.e. the temperature control medium circulating in the cycle advantageously has a controllable negative pressure relative to the environment, e.g. the pressure prevailing in the interior of the building.

[0020] Furthermore, the partial vapor pressure of the circulating temperature control medium can also be controlled by adjusting the concentration of the hygroscopic liquid or by diluting it. The concentration of the temperature control medium can be increased, for example, by adding heat and evaporating some of the water in the medium into the surroundings, and decreased by absorbing water vapor from the surroundings and / or by adding water to the temperature control medium.

[0021] In the context of the invention, a hygroscopic liquid is in particular a salt solution based on lithium chloride, lithium bromide or calcium chloride.

[0022] The capillary tube mat located inside the climate element comprises, in addition to the capillary tubes preferably formed of hollow fibers, two collecting tubes communicating with the capillary tubes, which serve for the supply and discharge of the temperature control medium into and out of the climate element acting as a heat exchanger and are part of the circuit for the circulating temperature control medium.

[0023] The collecting tubes can be designed as short pipe sections similar to junction boxes, into which the individual capillary tubes open radially, or the collecting tubes can be designed as preferably straight pipe sections, which can be arranged at different distances from each other or on a common axis. The arrangement is preferably chosen to achieve the most homogeneous distribution possible of the individual capillary tubes within the climate element.

[0024] Preferably, a heat exchanger designed as a climate element according to the invention has approximately 20-200 capillary tubes per square meter of the area of ​​the climate element.

[0025] Further embodiments and details of the invention are explained below with reference to exemplary embodiments in the drawing. The drawing shows: Figure 1 shows a first embodiment of a heat exchanger according to the invention in a partially cut-away front view; Figure 2 shows the heat exchanger according to Figure 1 in side view; Figure 3 of the heat exchanger according to Figure 1 Figure 4 shows a second embodiment of a heat exchanger according to the invention in a partially cut-away front view; Figure 5 shows the heat exchanger according to the invention. Figure 4 Figure 6 shows a further embodiment of a heat exchanger according to the invention in side view; Figure 7 shows an enlarged detail of the heat exchanger according to the invention. Figure 1Figure 8 shows an enlarged view of a heat exchanger according to the invention; Figure 9 shows an enlarged view of another heat exchanger according to the invention; Figure 10 shows a schematic diagram of a device according to the invention.

[0026] The Figure 10 Figure 1 shows a simplified schematic diagram of a device for air conditioning an interior space R of a building, which is not shown in detail and is filled with a corresponding volume of room air.

[0027] In order to be able to heat and / or cool this interior space R accordingly, the following are required in the illustrated embodiment according to Figure 10 Three heat exchangers 1 connected in parallel, with a structure that will be explained in more detail below, are installed in the interior space R and are in a heat exchange relationship with the interior space R.

[0028] The heat exchangers 1 are traversed by a temperature control medium in a manner known per se, which is contained in the Figure 10 The visible pipes circulate in a circuit K, which is maintained by a peristaltic pump 200. The circuit K for the temperature control medium also includes a corresponding storage tank 300 for any excess of the temperature control medium and a three-way valve 600, which can be controlled by a control module 500.

[0029] During circulation in circuit K, the temperature control medium passes through a heat exchanger 400 integrated into circuit K, which, depending on the air conditioning task (heating / cooling), is supplied with a corresponding heat or cold flow 800, which can be controlled via a control valve 700, and accordingly heats or cools the temperature control medium as it passes through the heat exchanger 400.

[0030] The temperature control medium, heated or cooled in heat exchanger 400, then enters heat exchanger 1. If the temperature control medium 1 was heated in heat exchanger 400, a corresponding heat flow is transferred to the interior space R for heating, based on the temperature difference. Conversely, if the temperature control medium 1 was cooled in heat exchanger 400, a corresponding heat flow is absorbed from the interior space R for cooling.

[0031] A key feature of the [something] from the Figure 10 The apparent device is that the temperature control medium circulating in circuit K is formed from a hygroscopic liquid, for example a salt solution based on calcium chloride, which is able to absorb moisture in the form of water vapor in addition to the temperature change described above, or to release it, for example, when heated accordingly.

[0032] The heat exchangers 1 in the interior space R, which will be explained in more detail below, are designed such that the temperature control medium is guided through pipes with liquid-tight but water vapor-permeable walls. This makes it possible to absorb and remove any excess water vapor present in the interior space R as the temperature control medium passes through the heat exchangers 1, thus allowing the room air to be dehumidified as required. Alternatively, for example, if the temperature control medium is heated appropriately, a corresponding proportion of water vapor can be released from the temperature control medium as it passes through the heat exchangers 1, so that the room air can be humidified as required.

[0033] The appropriate conditioning of the water content contained in the temperature control medium, which is designed as a hygroscopic liquid, i.e., the concentration of the hygroscopic liquid, is set via the storage tank 300 using the three-way valve 600, which supplies the temperature control medium with correspondingly different salt concentrations from different extraction points of the storage tank 300, for example in the bottom area and on the surface, according to the requirements and controlled via the control module 500.

[0034] Additionally, regeneration and / or replacement of the temperature control medium supplied to circuit K can be carried out via an external circuit 900 (not shown in detail) running through storage tank 300. Regeneration can, for example, involve heating the temperature control medium in appropriate heat exchangers to evaporate any water contained in the temperature control medium, or external water intake from or to the environment to adjust the temperature control medium to a desired concentration.

[0035] From the Figures 1 to 3 A first embodiment of a heat exchanger 1 in the form of a rigid climate element is shown in more detail, which can be used for temperature control and humidity regulation of an interior space of a building not shown here.

[0036] Heat exchanger 1 is part of the system exemplified by the Figure 10The heat exchanger 1, which describes a circular process, is designed as a rigid panel, for example, for mounting on a ceiling or wall of the building space to be air-conditioned. The heat exchanger 1 comprises a frame formed from dimensionally stable metal profiles 5, into which a porous, hardening filler 30, for example based on diatomaceous earth, is introduced, filling the frame to form a closed, rigid panel.

[0037] The filling material 30 used has a corresponding porosity, so that the passage of larger quantities of water vapor into the interior of the heat exchanger 1, which is designed as a climate element, or out of the interior of the heat exchanger 1 is possible.

[0038] Within the filling mass 30 forming the visible surfaces of the heat exchanger 1, a capillary tube mat is embedded, which is formed by two collecting tubes 6 and capillary tubes 2 running between them, which can be permeated by the temperature control medium circulating in the cycle.

[0039] A key feature of the described design is that the capillary tubes 2 have walls that are liquid-tight but water vapor permeable, which can be ensured in particular by the fact that the capillary tubes 2 are made of hollow fibers with water vapor permeable but liquid-tight membrane walls.

[0040] Due to the liquid-tight design of the walls of the individual capillary tubes 2, the temperature control medium, consisting of a hygroscopic liquid, is guided between the collecting tubes 6 through the heat exchanger 1, resulting in heat exchange with the surrounding room air. Simultaneously, moisture contained in the room air in the form of water vapor can pass through the filling material 30 into the interior of the heat exchanger 1 and is absorbed there by the hygroscopic liquid circulating in the capillary tubes 2, as it can penetrate the walls of the individual capillary tubes 2, which are permeable to water vapor.

[0041] Conversely, if the room air is sufficiently dry, it is also possible that water vapor from the hygroscopic liquid circulating in the capillary tubes 2 as a temperature control medium escapes through the walls which are permeable to it and is released from the heat exchanger 1 via the permeable filling mass 30 to the room air for humidification.

[0042] One such example from the Figures 1 to 3 The visible rigid climate element 1 can, for example, have a width BP of about 600 mm, a height HP of about 1200-1800 mm and a depth TP of about 15-20 mm.

[0043] Furthermore, one can recognize from the Figure 3 , that to fix the position of the capillary tubes 2 within the heat exchanger 1, layers of fabric 4, for example made of polyamide, may be introduced to hold the capillary tubes 2 in a central area of ​​the heat exchanger.

[0044] In the exemplary embodiment according to the Figures 1 to 3The collecting pipes 6 are designed as short pipe sections in the form of a junction box, from which the individual capillary tubes 2 extend radially. This is described in more detail in the Figure 7 visible.

[0045] It can be seen that each individual junction box serving as a collector pipe 6 has an internal cavity 7 which communicates with the inlet and outlet to the heat or cold source in a manner not shown in detail. The individual tubular hollow fibers forming the capillary tubes 2 are fixed and sealed within the body of the collector pipes 6 by means of synthetic resin 80.

[0046] In contrast, this shows that Figure 4 The illustrated embodiment shows the design of the collecting tubes 6 as straight pipe sections which are positioned at the upper and lower ends of the heat exchanger 1 and between which the individual capillary tubes 2 run in fluidic connection.

[0047] According to Figure 5In such a configuration, a surface of the heat exchanger, preferably on the visible side, can be formed by the filling material 30, for example based on diatomaceous earth, whereas on the rear side an insulating plate 8 made of suitable insulating material, e.g. based on polyethylene, is arranged to give the heat exchanger the desired dimensional stability and to prevent heat loss to the building wall. The collector pipes 6 are arranged with respect to the capillary tubes 2 such that the latter open radially into them. In the exemplary embodiment according to Figure 6 In contrast, an arrangement is chosen in which the capillary tubes 2 enter the collecting tubes 6 approximately tangentially, so that on the left side a flush transition is formed between the collecting tubes 6 and the surface structures 3, between which the capillary tubes 2 are arranged.

[0048] This different arrangement, with a radial opening of the capillary tubes 2 into the cavity 7 of the collecting tubes 6 on the one hand and a more tangential opening on the other, is also evident from a comparison of the designs according to Figures 8 and 9 It is evident. It can also be seen that the capillary tubes are fixed in the corresponding openings of the collecting tubes 6 by means of a suitable synthetic resin 100 in a sealing manner.

[0049] In addition to arranging heat exchangers inside a building and exchanging heat with the environment within the building's interior, it is also possible to position rigid heat exchangers on the building's exterior, thus enabling heat exchange with the environment outside. In this case, the heat exchangers are made of suitable materials resistant to the prevailing climatic conditions. For example, rigid heat exchangers can be manufactured with foam concrete-based fillers that exhibit properties similar to human skin or plant leaves. When a hygroscopic fluid circulates as a temperature control medium within the hollow fibers, this allows for thermal and material exchange with the building's environment.

[0050] By attaching such heat exchangers directly to the outer wall or the outer windows of a building, these heat exchangers form intermediate layers between the original building wall or the windows to the outside air, and the temperature of the heat exchanger is controlled by the circulation of the temperature control medium and its temperature depending on the weather.

[0051] At higher outside temperatures, the heat load at the heat exchanger can be absorbed by the circulating temperature control medium before it comes into contact with the building's exterior walls or windows, and then transferred to another point in the temperature control medium's circuit. This reduces the thermal load on a building room, and the absorbed heat can then be transferred, for example, to a combined heat and power (CHP) process via another heat exchanger.

[0052] Since the partial vapor pressure of the temperature control medium in the capillary tubes also increases due to the temperature rise in the heat exchanger, a partial evaporation of the temperature control medium occurs through the capillary tubes and the water vapor-permeable heat exchangers into the environment, similar to perspiration. This is comparable to the sweating of human skin. Consequently, the building equipped in this way is cooled.

[0053] At low outside temperatures, however, the heat that escapes to the outside through the building's facade or glazing is captured in the heat exchangers located on the outside of the building, leading to an increase in the temperature of the temperature control medium circulating through the heat exchangers, and can then be returned to the building's interior.

[0054] With the heat exchangers 1 described above, which have liquid-tight but water vapor-permeable walls of the capillary tubes 2, made, for example, of corresponding hollow fibers, it is possible, when supplied with a temperature control medium formed by a hygroscopic liquid, not only to heat or cool an interior space R, but also to supply moisture to it or remove moisture from the room air as required.

Claims

1. Device for air-conditioning buildings with a heat or cold source and at least one heat exchanger and a temperature control medium circulating in a circuit between the heat or cold source and the at least one heat exchanger, wherein a hygroscopic liquid is provided as the temperature control medium and the heat exchanger is designed to be liquid-tight but water-vapor-permeable in such a way that water vapor can be absorbed from the surroundings of the heat exchanger or released to the surroundings by means of the temperature control medium via the at least one heat exchanger, characterized in that the at least one heat exchanger is formed as an air-conditioning element with an embedded capillary tube mat which is formed by two collecting tubes with capillary tubes which extend between them and through which the temperature control medium can flow, wherein the walls of the capillary tubes are designed to be liquid-tight but water-vapor-permeable, and the air-conditioning element is designed as a rigid panel for wall or ceiling mounting and comprises a supporting frame and a porous water-vapor-permeable filling compound based on diatomaceous earth which is introduced within the supporting frame and within which the capillary tube mat is embedded.

2. Device according to claim 1, characterized in that the capillary tubes are formed by hollow fibers with water-vapor-permeable but liquid-tight walls.

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