1. Field of the Invention
The invention relates to an air conditioning system for a building.
2. Description of the Background Art
WO 2007/068481 A1, which corresponds to U.S. Publication No. 2009000327, describes a heat pump according to the adsorber/desorber principle, wherein a heat-transporting fluid can flow around a stack of hollow elements, each containing a working medium, on an adsorption/desorption side of the hollow elements via a plurality of flow paths. The flow paths are alternately cyclically interconnected by a pair of two rotary valves, wherein the large number of separate flow paths improves the overall efficiency of the heat pump. On an opposing evaporation/condensation side of the hollow elements, a second fluid, for example air, flows around them, which is likewise conducted alternately over the hollow elements by a pair of two rotary valves. An air conditioning system according to the invention is based on such a heat pump, wherein depending on the requirements of the invention, reference is made to the detailed explanations of the heat pump.
Previously, given the complex design, such heat pumps have been considered as central large-scale plants for building air conditioning, wherein the heat pump should be disposed centrally, for example in a basement or beneath the roof of a building, and heated or cooled water is conducted via a line network to different heating or cooling sites of a building.
It is therefore an object of the present invention to provide an air conditioning system for a building that has a compact design, in particular is designed to be retrofittable, and to be used as needed.
By designing the system as a local unit, the heat pump can be provided in a manner similar to a facade or window air conditioner. The heat pump will then typically condition only one room, or a few rooms, and the output and size thereof are dimensioned accordingly.
In an embodiment, at least two locally disposed heat pumps are provided. These local heat pumps can be connected to a fluid line system of the building, similar to a radiator. In the case of retrofits, it may also be possible to use existing pipes of a heating system for this purpose or to embed the retrofits in the exterior facade insulation as part of the energy-related renovation measure. The fluid line system can notably be a liquid line system.
In a detailed design, the locally disposed heat pump is designed for a cooling power of no more than 10 kilowatts, and more particularly no more than 5 kilowatts, in the normal operating mode. In this way, an air conditioning unit is made possible that is flexible to install and, in particular, can also be retrofitted and that is sufficiently dimensioned for individual rooms of average size.
In an embodiment of the invention, the heat sink can be designed as a heat exchanger through which air flows. In a possible detailed design, the heat exchanger is designed as an integrated unit comprising the locally disposed heat pump. In such a type, the heat pump can be connected to a dual-line system of the building, whereby the installation complexity and costs are reduced.
In an embodiment, the locally disposed heat pump can be disposed in an outside wall region of the building, wherein at least one outside wall breakthrough connected to the heat pump enables air exchange with a room of the building. This arrangement has the advantage that circulating air and/or outside air can be fed selectively, or in a mixable manner, for example as circulating, mixed or fresh air, to the conditioned region. It is particularly preferred if the heat pump comprises an adjustable mixing member, wherein at least an air current of the group including outside air, building air or conditioned feed air can be mixed with another air current of the group and divided in a complementary fashion to an evaporation zone and a condensation zone of the heat pump. In this way, the air temperature, humidity and air renewal rate can be easily influenced in the room and the operation and efficiency of the heat pump can be further optimized, and additionally supply air/exhaust air heat recovery can be achieved. In an advantageous detailed design, the mixing member is disposed on the inlet side of the heat pump. The term ‘circulating air’, within the context of the present invention, shall generally be understood to mean building air that is withdrawn from the building. Depending on the particular use, this circulating air/building air can then be recirculated to the building or dissipated to the outside.
In a particularly simple and cost-effective installation type of the air conditioning system, the fluid is connected to the heat pump by way of a dual-line system. The dual-line system will generally lead to either a heat source or heat sink, wherein the respectively other component is provided locally or decentralized in the region of the heat pump, for example in the form of a recooling unit operated by outside air.
In an alternative embodiment, which may be preferred depending on the requirements, the fluid is connected to the heat pump by way of a triple-line system, wherein one of the lines leads to the heat source and another one of the lines leads to the heat sink, and wherein a third line forms a mean temperature return of the heat pump. The flow direction of the fluid runs preferably from the heat source to the heat pump and from the heat sink to the heat pump, wherein the fluid flow in the mean temperature return leads away from the heat pump. In a preferred detailed design, the third line is connected by way of a branch to the heat source and the heat sink. In a further preferred embodiment, the heat pump is spatially separated from both the heat source and the heat sink, which further reduces the size and makes the system more effective. In addition, in this way it is easy to switch from cooling operation to heating operation of the heat pump. In order to optimize the efficiency of the heat pump, moreover a fourth line may be provided, which likewise forms a mean temperature return of the heat pump, wherein in particular the third line is connected to the heat source and the fourth line is connected to the heat sink. In this way, the different temperature levels of the returns to the heat source and to the heat sink are taken into consideration, which develop with optimized internal heat recovery of the heat pump, whereby slightly higher thermal ratios can be achieved. The thermal ratio of a thermally driven heat pump is the quotient of useful heating or cooling power and the required drive thermal output, and therefore constitutes a measure of the efficiency.
In an embodiment comprising at least three lines, at least the third line can be connected to a mean temperature heat accumulator. In this way, the centrally developing adsorption heat can be utilized, which is dissipated via the hot or mean-temperature return of the heat pump. A mean temperature heat accumulator within this meaning can be any thermodynamically expedient storage or transfer of this heat volume. In particular, it can be designed as at least one of the group of process water accumulator, hot water accumulator or low-temperature heater. A low-temperature heater shall generally be understood to mean any type of component activation of the building, for example floor or wall surface heater.
In general, the heat pump can be designed so that it has both a cooling operating mode for cooling air that is fed to the building and a heating operating mode for heating air that is fed to the building. A heating operating mode shall preferably be understood to mean that not only energy of the heat source is delivered to the building, but that in fact additional heat pumping takes place to improve the utilization of energy. As a result, during such an operation, for example, air is conducted to the outside, which has been cooled by the heat pump driven by the heat source/heat sink to below the outside temperature. The amount of heat withdrawn from the outside air is then additionally available for heating the building.
In an embodiment and operating mode, in the heating mode the portion incurred as adsorption heat is transferred via the fluid circuit to the heat accumulator or the heat consumer of the building, and the portion incurred as condensation heat is transferred to the useful air of the building, while the evaporation heat is withdrawn from the air current delivered to the outside air. When using building air as the heat transfer medium, this corresponds to exhaust air/supply air heat recovery with a concurrent temperature increase due to the heat pump effect.
In an embodiment of the invention, a portion of the hollow elements around which air flows is provided with a water-storing device. In this way, condensation water that precipitates from the cooled air during an evaporator operation of the hollow element can be stored distributed in an areal manner, so that it evaporates again in the subsequent internal, and heat-emitting, condensation operation of the same respective hollow element and can be emitted to the air. In the usual operating mode, the condensation water precipitated from the air is conducted as steam to the outside or emitted to the outside air. In total, in this way an enthalpy transfer medium is formed for the condensation water formed when the useful air cools, by which an enthalpy exchange can be achieved between the supply air and exhaust air from the room to be conditioned. In addition, this has the considerable advantage that no area of the air-side heat pump collects any quantity of water over an extended period, preventing the formation of microorganisms and/or the odor-intensive metabolic products thereof. Typical cycle times of such a heat pump are 10 minutes, so that the surface of a hollow element of the invention around which air flows, in simplified terms, is alternately moist for 5 minutes and dry for 5 minutes.
In a simple and preferred detailed design, the water-storing device is designed as a rib member having capillary structures and/or as a hydrophilic coating. For example, conventional louvered corrugated fins are suited to retain condensation water in a capillary manner in the fine louver slits, which were originally provided in heat exchangers to cause better turbulence of the air current. A possible embodiment would therefore be to provide conventional louvered fins in the gap between adjoining hollow elements through which air flows, whereby at the same time the heat transfer between the air and the hollow elements is improved.
In an embodiment, an air filter can be designed on the heat pump for filtering outside air and/or circulating air, so that pollen, dust and the like are easily filtered out.
In general, the heat sink of an air conditioning system according to the invention can have any arbitrary design, preferably, for example, as at least one of the group including a heat exchanger through which air flows, body of flowing water, wet cooling tower or geothermal probe. Likewise, the heat source can have any arbitrary design, and in a particularly preferred embodiment it is designed as at least one of the group including a solar thermal system, district heating connection, boiler or co-generation plant.
In an embodiment, the heat sink and/or the heat source can be switched or connected, depending on the heating or cooling operating mode.
In an embodiment of the invention, the local heat pump comprises at least one integrated pump for delivering the fluid. In this way, when a plurality of heat pumps are connected in parallel to a fluid line system of the building, each heat pump can branch off an individual amount of fluid, without impairing the operation of the other heat pumps. This is preferably supported in that the pressure differential of the central feed lines coming from the heat source and heat sink and leading to the heat pumps is regulated by means of central pumps in relation to the return.
In an embodiment, the heat pump has an electronic controller, wherein in particular a rotational speed of the rotary valve and a volume flow of the fluid can be controlled in an actuatable manner. The volume flow and rotational speed are notably linked by a fixed characteristic curve. Particularly with a heat pump according to the invention, electronic control is particularly suited because optimizing the efficiency under changing operating conditions is key here.
In a further embodiment of the invention, at least a fluid-side part of the heat pump comprises exactly only one rotary valve. In this way, the size, number of moving components, and manufacturing costs of a heat pump can be reduced. So as to improve the efficiency, the exactly one rotary valve alternately interconnects at least 4, and more particularly at least 6, separate flow paths. The document WO 2007/068481 A1 describes in detail only heat pumps that have pairs of two opposing rotary valves, respectively, both on the fluid side and on the air side. Hereinafter, additionally an embodiment is described in which exactly only one rotary valve is required at least on the fluid side, with the overall function being analogous otherwise.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
The air-conditioning system according to
The fluid, which in the present case is a water/glycol mixture, is connected by way of a dual-line system 4, which has a first line 4a leading from the heat source and a second line 4b leading back to the heat source, to the heat pumps, which are connected to the line system 4 in parallel to each other. A circulating pump 5 applies a pressure to the line system 4, wherein each of the heat pumps 2 connected in parallel additionally comprises a dedicated feed pump 6 (see
The local heat pumps 2 are each dimensioned such that they produce a cooling power between 1 kW and 5 kW in a typical cooling operating mode. With respect to the design thereof, they correspond to a heat pump according to WO 2007/068481 A1 or a heat pump that is modified in this respect, comprising only a single fluid-side rotary valve. Such a rotary valve is described below by way of example and shown schematically in
In addition to the aforementioned feed pump 6, the local heat pumps 2 shown in detail in
Depending on the current operating mode of the individual hollow elements, the air-side region is divided into an evaporator region 9 and a condenser region 10. Depending on the requirements and operating conditions, circulating air (building air) L1 and/or outside air L2 is fed for conditioning via two fans 11, 12 to the region 7. On the outlet side of the region 7, an air current L3 is dissipated to the outside (exhaust air) and another air current L4 (useful air), which is conditioned if desired, is fed to the building.
The air currents L1 out of the building and L4 into the building are conducted locally via wall or ceiling breakthroughs (see for example
All mixing ratios between the extreme settings described above can, of course, also be adjusted, depending on the requirements.
So as to improve the efficiency and suppress microorganisms, the hollow elements of the heat pump 2 are provided on the air side with a water-storing device, in the present case are soldered-on louvered corrugated fins (not shown). Because during a complete cycle, which typically lasts approximately 10 minutes, the hollow elements undergo an evaporator mode and a condenser mode, in the first case condensation water is deposited from the conditioned air and is held in a capillary manner by the louvered fins, whereupon in the condensation mode the hollow elements are dried again by means of the dissipated air. Depending on the design, the entire cycle may also take up to 20 minutes or longer.
The second embodiment of the invention shown in
The heat pump 2 is connected to the triple-line system such that both a hot fluid line 4a leads from the heat source 1 and a cold fluid line 4c leads from the heat sink to the heat pump, wherein accordingly an additional circulating pump 5′ is provided in the line 4c. A mean temperature line 4b leads away from the adsorption module 8 and opens via a T-piece 13, respectively, into a common return line, wherein a first branch 4d leads back to the heat source and a second branch 4e leads back to the heat sink.
The heat pump 2 comprises two separate feed pumps 6, 6′, by means of which an adsorption-side fluid flow 8b and a desorption-side fluid flow 8a of the adsorption module 8 are delivered separately. Depending on the operating conditions, the volume flows 8a, 8b may be different. Downstream of the two pumps 6, 6′, the flows 8a, 8b unite to form a flow that opens into the returning mean temperature line 4b (see
It is pointed out that heating operation is also possible in the first embodiment using local heat sinks. To this end, an adjustable air by-pass must be provided, so that in the heating operation the useful air is conducted over the heat exchanger 3a of the recooling unit 3.
In a further embodiment, which is not shown, a quadruple-line system is provided to improve the efficiency. Contrary to the triple-line system, separate returning lines are provided instead of a collecting line 4b. The colder discharge from the adsorption module 8 is recirculated to the heat sink and the warmer discharge is recirculated to the heat source.
The rotary valve 100 comprises a plurality of inlets 101 to 112 and outlets 201 to 212, which can be individually associated with the inlets 101 to 112 via connecting lines 126 or 128 and 129. The inlets and outlets are connected, for example, to thermally active modules (adsorber/desorber hollow elements) 301 to 312. The rotary valves 100 comprises a switching member 114, which in turn comprises a rotary body 115, which can be rotated as indicated by an arrow 116. A first heat exchanger in the form of a cooler 118 is shown in the rotary body 115, with a pump 119 being connected downstream of the cooler. A second heat exchanger is configured as a heater 120.
The rotary valve 100 shown in
Each of the inlets 101 to 112 and each outlet 201 to 212 are associated with an opening in an end face of the housing 125, which substantially has the shape of a hollow circular cylinder. The inlets and outlets open into the end faces of the housing 125. Each opening in the housing 125 can be associated with an opening in the rotary body 115. Because of these associations, each of the inlets 101 to 112 can be connected in a defined manner to the related outlet 201 to 212. In the embodiment shown in
The inlets 101 and 107 are connected to the related outlet 201, 207, respectively, via interrupted connecting channels 128, 128. The connecting channels 128, 128 are divided by means of separating walls or the like into sub-channels 128a, 128b or 129a, 128b such that they force a flow diversion over the cooler 118 or the heater 120. For this purpose, four annular chambers 131 to 134 are provided inside the housing 125, which in the map projections of
The heater 120 is connected via the annular chamber 134 to the outlet 201. Analogously, the inlet 107 is connected via the annular chamber 131 to the cooler 118, which in turn is connected via the annular chamber 132 and the interrupted connecting channel 128 to the outlet 207. By rotating the rotary body 115 in the direction of the arrow 116, the through-channels 126 and the interrupted connecting channels 128, 129 are associated with other inlets and outlets. This displacement preferably takes place incrementally, so that the rotary body 115 always come to a stop when the mouth openings of the channels 126, 128, 129 provided in the rotary body 115 cover the corresponding openings in the housing 125.
Four annular chambers or annular spaces 131 to 134 are connected via a radial opening 141 to 144 to the related connecting channel 128, 129. The radial openings 141 to 144 constitute a radial through-window, which creates a fluid connection between the annular chambers 131 to 134 and the radially inwardly disposed axial connecting channels 128, 128, which contrary to all other connecting channels 126 are divided by at least one dividing wall 128c or 129c into two sub-channels 128a and 128b, or 129a and 129b. The association between the sub-channels 128a, 128b or 129a, 129b and the annular chambers 131 to 134 is preferably selected so that in each case two adjoining annular chambers 131, 132 and 133, 134 are connected to corresponding, which is to say mutually aligned, inlets 101; 107 and outlets 201; 207. In this way, one fluid path always leads through the heater 120 and another of the total of twelve available fluid paths leads through the cooler or recooling unit 118, depending on the position or rotation of the rotary body 115.
In
It is apparent from
In the case of indirect air cooling by way of a likewise liquid heat transfer medium, the use of a slightly modified valve is advantageous for controlling the fluid circuits of the evaporation/condensation zones identified as zones B, the map projection of such a valve being shown in
As is shown in
This modified embodiment enables an association of thermally active modules 301 to 312 that is dependent on the switch position of the rotary valve with at least two separate fluid circuits driven by dedicated feed devices, with the associated modules experiencing parallel flow inside these fluid circuits.
Because of the respective parallel arrangement of two groups of through-channels 128 and 129 in the rotary body 115, a plurality of radial through-windows are required, which each establish a flow connection into a common of the total of four required annular chambers. In a preferred embodiment, the separating walls within a group of through-channels can be eliminated in the rotary body, whereby then each annular chamber only requires one large radial through-window, which is not shown in the illustration here in detail.
In a further embodiment, which is not shown in detail in the illustration, the respectively last channel of a group of parallel channels (for example 102/202 and 108/208) comprises no radial breakthrough to an annular chamber, whereby flow is suppressed. In this way, no flow takes place through the connected modules. This can have advantages during the process changes between condensation and evaporation phases, which entail intermediate temperatures that cannot be used further.
The two embodiments according to
The advantages of the rotary valve 100 include the following: high integration of switch functions replaces two conventional rotary valves; reduced complexity for drive and control; compact, material-saving design; simple, cost-effective to produce, for example from plastic injection molded parts; easy-to-implement, low-wear surface seal using ceramic disks or ceramic plates 151, 152; short flow paths with low heat exchange between the individual flow paths; low friction and required driving torque; and low by-pass losses.
The individual characteristics of the different embodiments can of course be expediently combined with each other, depending on the requirements. When directly using air to transfer the evaporation and condensation heat, it is in particular advantageous to not deviate from the solution comprising two communicating rotary valves in keeping with WO 2007/068481 A1.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
Number | Date | Country | Kind |
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DE 102008053554.0 | Oct 2008 | DE | national |
This nonprovisional application is a continuation of International Application No. PCT/EP2009/063794, which was filed on Oct. 21, 2009, and which claims priority to German Patent Application No. DE 10 2008 053 554.0, which was filed in Germany on Oct. 28, 2008, and which are both herein incorporated by reference.
Number | Date | Country | |
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Parent | PCT/EP2009/063794 | Oct 2009 | US |
Child | 13095183 | US |