The invention relates to an arrangement, in particular, a refrigerating machine or a heat pump, as well as a method for operating this arrangement.
Thermally powered sorption refrigerating systems have a high energy savings potential since inexpensive waste or excess heat is used and, in this way, expensive mechanical drive energy can be saved. In the case of stationary applications, the electrical networks can be relieved, particularly in warm time zones and climate zones with a high level of cooling demand. In the cold season, the systems can also be used as heat pumps, which boost additional environmental heat to a temperature level sufficient for heating purposes by means of burner heat.
Against this background, from the most recent background art, apparatuses are known where porous solid materials are used, which react with a working material subject to the implementation of heat and do not have any moving and thereby fault-prone wear parts within the range of the working material.
However, with relation to continuously working absorption systems, adsorption heat pumps or adsorption refrigerating systems implemented with the aid of such thermochemical reactors have the disadvantage that the periodic temperature changes with cycled thermal masses result in efficiency compromises, which reduce the achieved power density or power efficiency.
In this context, DE 102006043715 A1 discloses an adsorption heat pump where a stratified heat store is used. This allows for a time-delayed storage and reuse of sensitive and latent heat during the adsorption cycle. However, such stratified heat stores cannot be used everywhere due to its great volume.
It is the object of the present invention to indicate new ways to develop sorption heat pumps and sorption refrigeration systems, in particular, having improved efficiency.
This task is achieved by means of the object of the independent patent claims. Favourable embodiments are the object of the dependent patent claims.
The basic idea of the invention is to equip an arrangement of an adsorption heat pump or an adsorption refrigerating machine based on cyclically operating thermochemical reactors with a temporary heat store, which has two partial stores to hold a heat transfer fluid at two different temperature levels. This temporary heat store is used to temporarily store heat contained in the heat transfer fluid in the case of thermally cycling the thermochemical reactor and in the case of switching the thermochemical reactor between two different temperature levels associated therewith. Under the term “thermochemical reactor”, in general, a reservoir with at least one working material and one integrated heat transfer structure is understood, using with at least on exothermic or endothermic reaction or phase change can be instigated independently of a marginal temperature condition subject to the supply and dissipation of heat. Thereby, it can have to do with a sorption reactor or a phase changer, in particular, a condenser and/or a vaporiser. Such special embodiments, components or subcomponents are also known under the terms “sorber”, “sorption reactor”, “thermochemical store” or “phase changer”.
The present temporary heat store according to the invention that is used allows for the temporary storage of the heat transfer fluid at the temperature level of a heat source of the arrangement in the first partial store and the simultaneous temporary storage of the heat transfer fluid at the temperature level of a heat sink of the arrangement in the second partial store of the temporary heat store.
In the case of the temporary heat store according to the invention, a volume reduction of the second partial store is associated with a volume increase of the first partial store and vice versa. Since both volume-variable partial stores comprise the same overall volume, introducing the heat transfer fluid at the temperature level of the heat source into the first subspace makes discharging the heat transfer fluid at the second temperature level from the second partial store easier and vice versa. In this way, undesired energy loss of the thermochemical reactor during thermal cycling, meaning when switching over between the two temperature levels of the heat source and the heat sink can be minimized. In the result, this leads to an improved efficiency of the arrangement according to the invention with relation to conventional arrangements.
An arrangement according to the invention, in particular, a refrigerating machine or a heat pump, comprises a first heat reservoir, which acts as a heat source as well as a second heat reservoir, which acts as a heat sink. The arrangement furthermore comprises at least one thermochemical reactor, which is or can be thermally and fluidically connected to the heat reservoirs. Preferably, the thermochemical reactor is an adsorption refrigerating machine or an adsorption heat pump or is a crucial functional component thereof.
Furthermore, the arrangement comprises a heat transfer fluid circuit, in which a heat transfer fluid is arranged to transport heat between the two heat reservoirs and the thermochemical reactor. A temporary heat store is provided in the heat transfer fluid circuit to temporarily store the heat transfer fluid. According to the invention, the temporary heat store comprises a first partial store with a variable storage volume. Furthermore, the temporary heat store comprises a second partial store with a variable storage volume that is thermally and fluidically separated from the first partial store.
At least one, preferably two conveying device(s) of the arrangement according to the invention available in the circuit is used to propel the heat transfer fluid in the heat transfer fluid circuit. Furthermore, the arrangement comprises a valve system that is available in the heat transfer fluid circuit and comprises at least one adjustable valve device. By means of this at least one adjustable valve device, the heat transport between the two heat reservoirs, the thermochemical reactor and the temporary heat store can be controlled by means of the heat transfer fluid. For controlling the said valve system, the arrangement according to the invention only comprises a regulation/control device.
In a preferred embodiment, at least two thermochemical reactors are provided, which each comprise a separate reservoir with a heat transfer structure with a fluid inlet and a fluid outlet. The at least two thermochemical reactors are thereby arranged with a fluidic parallel connection to one another, meaning the fluid inlets and the fluid outlets of the at least two thermochemical reactors are or can be fluidically connected to each other by means of the valve system. The provision of two or a greater number of separate thermochemical reactors allows for a time-delayed switching of the available thermochemical reactors from a state with a higher temperature T1 into a state with a temperature T2 that is relatively lower than temperature T1. The time-delayed switching of the individual thermochemical reactors results in a particularly low energy loss during the temperature change in connection with the temporary heat store.
In the case of a favourable further embodiment, the valve system comprises a first adjustable valve device for each available thermochemical reactor, by means of which the fluid inlet of the respective thermochemical storage can be optionally connected to the first or the second heat reservoir. In the case of this variant, the valve system comprises a second adjustable valve device for each available thermochemical reactor, by means of which the fluid outlet of the respective thermochemical reactors can be optionally connected to the first or the second heat reservoir. This measure allows for a favourable control of the time-delayed switching process between exothermic and endothermic subprocesses running at different temperature levels.
Being particularly preferred, the regulation/control device is set up/programmed for the time-delayed adjustment of the individual first valve devices and for the time-delayed adjustment of the individual second valve devices. This means that the regulation/control device is capable of adjusting the first and second valve devices via suitable control lines individually, meaning independently of one another. The regulation/control device can comprise a control unit or a storage unit. In the latter, a computer programme code can be stored, which is processed by the control unit to carry out the time-delayed switching process of the individual first and second valve devices. In the said computer program code, the algorithm for the time-delayed switching of the first and the second valve devices is thereby coded.
Expediently, the temporary heat store is fluidically connected in parallel to the second valve devices in such a way that the fluid inlet of the first heat reservoir fluidically communicates with the first partial store and the fluid inlet of the second heat reservoir fluidically communicates with the second partial store.
In a favourable further embodiment, the first valve device and the second valve device each comprise a 3/2-way valve. This allows for a simple implementation of an optional fluidic connection of the at least one thermochemical reactor either with a first heat reservoir at temperature level T1 or the second heat reservoir at temperature level T2.
In another preferred embodiment, an equalizing reservoir is arranged in the heat fluid circuit to hold the heat transfer fluid.
In the case of another preferred embodiment, the temporary heat store is designed to simultaneously hold and output a first and a second fluid mass of the heat transfer fluid, wherein the two fluid masses can have various temperature stratifications between the temperature limits T1 and T2. This makes it possible to simultaneously temporarily store fluid mass within the temporary heat store for carrying out an energy-efficient temperature change between the temperature level of the heat sink and the heat source.
Being particularly favourable, the first partial store of the temporary heat store is fluidically connected to the first heat reservoir and the second partial store of the temporary heat store is fluidically connected to the second heat reservoir.
This measure allows for a simple supply of heat transfer fluid near the temperature T1 from a thermochemical reactor to be cooled into the temporary heat store. This measure also allows for a simple supply of heat transfer fluid near the temperature T2 from a thermochemical reactor to be heated into the temporary heat store.
In accordance with a particularly preferred embodiment, the temporary heat store is designed as a reservoir. In the case of this variant, the reservoir comprises a housing, in the interior space of which a separation element is movably arranged, which divides the interior space into a volume-variable first partial store and a second partial store, which is also volume-variable and is thermally insulated from the first partial store. A first through-opening is provided in the housing for the introduction and discharge of the heat transfer fluid into the or from the first partial store. Furthermore, a second through-opening is provided in the housing for the introduction and discharge of the heat transfer fluid into the or from the second partial store.
In the case of a favourable further embodiment, the housing is designed to be oblong. Thereby, the first through-opening is arranged on a first longitudinal end and the second through-opening is arranged on a second longitudinal end situated opposite to the first longitudinal end. The large length/sectional ratio associated with an oblong shape of the housing serves the purpose that a temperature stratification of the fluid mass flowing in and out remains constant to a great extent and does not notably mix during the required storage time.
Expediently, the housing can be designed as a pipe body, which essentially extends in a straight line along an axial direction. In the case of this variant, the separation element abuts the inner side of a circumferential wall of the pipe body to form the two volume-variable partial stores along the axial direction in a moveable manner. Such a construction is easy to manufacture on a technical level, thereby being associated with low manufacturing costs.
In another favourable further embodiment, a first sensor element is provided on the first through-opening, by means of which it can be determined whether the separation element is situated in a first end position, in which the separation element has a minimum distance away from the first through-opening. In addition or as an alternative, in the case of this variant, a second sensor element can be provided on the second through-opening, by means of which it can be determined whether the separation element is situated in a second end position, in which the separation element has a minimum distance away from the second through-opening. In this way, in the case of thermal cycling the thermochemical reactor, it can be determined when the heat transfer fluid has been completely taken from the two partial stores, because, in this case, the separation element is situated at a minimum distance away from the first or the second through-opening.
In the case of a preferred embodiment of the arrangement, an operating state can be set by the regulation/control device in the at least one adjustable valve device of the valve system, in which the heat transfer fluid circuit forms a first partial circuit. In this first partial circuit, the heat transfer fluid circulates between the thermochemical reactor and the second heat reservoir, and that being in such a way that heat is transferred from the thermochemical reactor into the second heat reservoir, meaning into the heat sink. In this way, heat can be dissipated from the thermochemical reactor in a particularly effective way.
Preferably, in this operating state, the first partial store has a maximum volume and the second partial store has a minimum volume. This means that the first partial store is filled with the heat transfer fluid, which has a temperature stratification near the temperature level of the heat source.
In the case of another preferred embodiment of the arrangement, an operating state can be set by the regulation/control device in the at least one adjustable valve device of the valve system, in which the heat transfer fluid circuit forms a second partial circuit. In this second partial circuit, the heat transfer fluid circulates between the thermochemical reactor and the first heat reservoir so that heat is transferred from the first heat reservoir, meaning from the heat source, into the thermochemical reactor.
Preferably, in this operating state, the second partial store has a maximum volume and the second partial store has a minimum volume. This means that the second partial store is filled with the heat transfer fluid, which has a temperature stratification near the temperature level of the heat sink.
In the case of another preferred embodiment of the arrangement, an operating state can be set by the regulation/control device in the at least one adjustable valve device of the valve system where heat transfer fluid is transported from the first partial store of the temporary heat store into the first heat reservoir. At the same time, heat transfer fluid from the first heat reservoir is transported into the thermochemical reactor and heat transfer fluid is transferred from the thermochemical reactor into the second partial store. In this way, heat can be supplied to the thermochemical reactor in a particularly effective manner and, thereby, the sensitive heat with a lower temperature can be stored for a later cooling process.
In the case of another preferred embodiment of the arrangement, and operating state can be set by the regulation/control device in the at least one adjustable valve device of the valve system where heat is transferred from the second partial store into the second heat reservoir by means of the heat transfer fluid. At the same time, heat from the second heat reservoir is transported into the thermochemical reactor and from the thermochemical reactor into the first partial store by means of the heat transfer fluid. In this way, heat can be discharged from the thermochemical reactor in a particularly efficient manner and, thereby, the sensitive heat with a higher temperature can be stored for a later heating process.
In a favourable further embodiment, the first and the second heat reservoir as well as the thermochemical reactor each comprise a fluid inlet and a fluid outlet for the introduction and discharge of the heat transfer fluid. In the case of this variant, the heat transfer fluid circuit comprises a first adjustable valve device, by means of which the fluid inlet of the thermochemical reactor can be optionally connected to the fluid outlet of the first or second heat reservoir. The heat transfer fluid circuit also comprises a second adjustable valve device, by means of which the fluid outlet of the thermochemical reactor can be optionally connected to the fluid inlet of the first or second heat reservoir.
The invention furthermore relates a method for operating an arrangement, preferably the one presented in the above, having a heat transfer fluid circuit, in which at least one thermochemical reactor, two heat reservoirs with different temperatures and a temporary heat store are arranged and are fluidically connected to one another by means of a heat transfer fluid circuit.
The temporary heat store used for carrying out the method according to the invention comprises two thermally and fluidically separate partial stores, in which a heat transfer fluid circulating within the heat transfer fluid circuit can be accepted and discharged in a way that is thermally and fluidically separated from one another. In accordance with the method according to the invention, in order to supply heat from the first heat reservoir into the thermochemical reactor by means of the heat transfer fluid, heat transfer fluid that is temporarily stored within the first partial store of the temporary heat store is taken and supplied to the first heat reservoir. At the same time, heat transfer fluid is discharged from the thermochemical reactor and introduced into the second partial store of the temporary heat store.
In order to carry out a temperature change of the thermochemical reactor from a high to a lower temperature level, increasingly cooler heat transfer fluid temporarily stored in the second partial store of the temporary heat store is taken and fed to the heat sink. At the same time, initially cool however increasingly warmer heat transfer fluid is discharged from the thermochemical reactor and introduced into the first partial store of the temporary heat store. In order to carry out a temperature change of the thermochemical reactor from a low to a higher temperature level, increasingly warmer heat transfer fluid temporarily stored in the first partial store of the temporary heat store is taken and fed to the heat source. At the same time, initially cool however increasingly warmer heat transfer fluid is discharged from the thermochemical reactor and introduced into the second partial store of the temporary heat store in a thermally stratified manner.
In a preferred embodiment of the method, at least two thermochemical reactors are available, which each comprise a separate housing as well as a fluid inlet and a fluid outlet. In the case of this variant, the at least two thermochemical reactors are fluidically connected to each other in parallel.
Thereby, the valve system comprises a first adjustable valve device for each available thermochemical reactor, by means of which the fluid inlet of the respective thermochemical reactor can be optionally connected to the first or the second heat reservoir. The valve system comprises a second adjustable valve device for each available thermochemical reactor, by means of which the fluid outlet of the respective thermochemical reactor can be optionally connected to the first or the second heat reservoir. The switching of the first existing valve devices to connect the thermochemical reactors to the first or the second heat reservoir takes place in a time-delayed manner. The switching of the available second valve devices to connect the thermochemical reactors to the first or the second heat reservoir also takes place in a time-delayed manner. The time-delayed switching of the individual thermochemical reactors makes a time-delayed regeneration of sensitive heat possible in connection with the temporary heat store, thereby resulting particularly low loss during the temperature change.
Other important features and advantages of the invention result from the subclaims, the drawings and the related figure description based on the drawing.
It is to be understood that the features explained in the aforementioned and following cannot only be used in the respectively indicated combination, but also in other combinations or alone, without departing from the scope of the present invention.
Preferred exemplary embodiments of the invention are represented in the drawings and will be described in more detail in the following description, wherein the same reference numbers will refer to the same or similar or functionally identical components.
On a schematic level respectively, the figures show
Under “thermochemical reactor”, in the present document, an apparatus is understood, in which conversion processes are instigated by supplying and dissipating heat at different temperatures T1, T2—also known by the person skilled in the art as reaction heat, sorption heat, or phase change heat. The thermochemical reactor 5 can comprise a reservoir 15, which is only schematically shown in the figures, in which thermochemical reactions take place, with a heat transfer structure for the supply and dissipation of the reaction heat. The first temperature T1 comprises a greater value than the second temperature T2, meaning the first heat reservoir 2a acts as a heat source, from which heat can be transferred to the thermochemical reactor 5 by means of the heat transfer fluid F. In contrast, the second heat reservoir 2b acts as a heat sink, at which heat can be transferred from the thermochemical reactor 5 by means of the heat transfer fluid F.
Furthermore, a temporary heat store 100 is available in the heat transfer fluid circuit 3 for temporarily storing the heat transfer fluid F. The temporary heat store 100 makes a temperature change of the thermochemical reactor 5 possible with very little energy loss from temperature T1 to temperature T2 and vice versa.
The construction of the temporary heat store 100 is shown in a schematic detailed illustration in
The temporary heat store 100 can also be referred to as a sensitive short-term heat store, regenerator or temperature changer and represents a component of the arrangement 1 according to the invention, which initially makes a temperature change in the thermochemical reactor 5 with low levels of energy losses at all possible.
The temporary heat store 100 is designed to simultaneously hold and output a first and a second fluid mass of the heat transfer fluid F with variously stratified temperature profiles. The temporary heat store 100 is designed to simultaneously hold and output a first and a second fluid mass of the heat transfer fluid F, wherein both fluid masses have different temperature stratifications, which are qualitatively characterized with different grey shades. The darker the grey shade, the higher the present local temperature level is.
As is evident in
The functional principle of the temporary heat store 100 is based on a thermally insulated fluid reservoir with end-side openings and a large length/cross-sectional ratio, within which an insulating displaceable separating body is arranged, as is schematically shown in
In the example scenario in
As can be recognized in the figures, the thermochemical reactor 5 and the temporary heat store 100 each have separate reservoirs 15 and 103.
As can be recognized in
The housing 104 is designed as a pipe body 105, which extends in a straight line along an axial direction A. The separation element 106 abuts the inner side 112 of a circumferential wall 111 of the pipe body 105 to form the two volume-variable partial stores 101a, 101b along the axial direction A in a moveable manner. The first through-opening 108a is arranged on a first longitudinal end 109a. The second through-opening 108b is arranged on a second longitudinal end 109b situated opposite to the first longitudinal end 109a.
As
The temperature profiles of the liquid columns of the heat transfer fluid F stored in the partial store of the temporary heat store causes that, in the case of pressing the temperature-stratified liquid column out of the second partial store, initially warm and then, however, increasingly cooler heat transfer fluid is pressed out. Thereby, this partial store can be used for the gradual cooling of a thermochemical reactor 5.
Complementary to this, in the case of pressing the temperature-stratified liquid column out of the first partial store, initially cool and then, however, increasingly warmer heat transfer fluid is pressed out. Thereby, this partial store can be used for the gradual heating of a thermochemical reactor 5.
According to
When now viewing
In the heat transfer fluid circuit 3, furthermore, a valve system 9 is available, which comprises a first adjustable valve device 10a and a second adjustable valve device 10b. By means of the two valve devices 10a, 10b, the heat transport between the two heat reservoirs 2a, 2b, the thermochemical reactor 5 and the temporary heat store 100 can be set and controlled as a result. In order to control the valve devices 10a, 10b of the valve system 9, a regulation/control device 4 is provided, which interacts which works together with the valve devices 10a, 10b.
The first and the second heat reservoir 2a, 2b as well as the thermochemical reactor 5 each comprise a fluid inlet 11a, 11b, 11c and a fluid outlet 12a, 12b, 12c for introducing and discharging the heat transfer fluid.
By means of the first adjustable valve device 10a, the fluid inlet 11b of the thermochemical reactor 5 can be optionally connected to the fluid outlet 12a, 12c of the first or the second heat reservoir 2a, 2b. By means of the second adjustable valve device 10b, the fluid outlet 12b of the thermochemical reactor 5 can be optionally connected to the fluid inlet 11a, 11c of the first or the second heat reservoir 2a, 2b.
As can be recognized in
In the following, now, a full thermal cycle of the thermochemical reactor 5 is explained where the thermochemical reactor 5 is switched between a first state at temperature T1 of the first heat reservoir 2a and a second state at temperature T2 of the second heat reservoir 2b.
Both valve devices 10a, 10b of the valve system 9 can be set into an operating state shown in
During the course of the thermal cycling, the thermochemical reactor 5 is now switched into a state at temperature T1 of the first heat reservoir 2a, whereby, initially, a temperature change is carried out in order to essentially heat the thermal masses of the reactor 5. In addition, both valve devices 10a, 10b are initially set into an operating state shown in
In this operating state, the temperature-stratified heat transfer fluid F of the first partial store 101a of the temporary heat store 100 is pressed into the heat reservoir 2a, whereby the thermal reactor is consequently heated up to its temperature level T1. In turn, the second partial store 101b of the temporary heat store 100 is filled with a cool and increasingly warmer heat transfer fluid F coming from the thermochemical reactor 5.
As soon as the heat transfer fluid F temporarily stored in the first partial store 101a of the temporary heat store 100 has completely been taken from the temporary heat store 100, the separation element 106 is in the aforementioned first end position, which can be detected by the regulation/control device 4 by means of the first sensor element 110a.
Being triggered by the first sensor element 110a, both valve devices 10a, 10b are initially set into an operating state that is schematically shown in
In the operating state schematically shown in
In order to instigate a “cooling mode”, subsequently, both valve devices 10a, 10b can be set into an operating state shown in
As soon as the heat transfer fluid F temporarily stored in the second partial store 101b of the temporary heat store 100 has completely been taken from the temporary heat store 100, the separation element 106 is in the aforementioned second end position, which can be detected by the regulation/control device 4 by means of the second sensor element 110b. In this state, the first partial store 101a is completely filled with the heat transfer fluid F (cf.
The valve system (9) comprises a first adjustable valve device 10a for each of the three thermochemical reactors 5a, 5b, 5c, by means of which the fluid inlet 11b of the respective thermochemical reactor 5a, 5b, 5c can be optionally connected to the first or the second heat reservoir 2a, 2b of the temperature T1 or T2. The valve system 9 furthermore comprises a second adjustable valve device 10b for each of the three thermochemical reactors 5, by means of which the fluid outlet 12b of the respective thermochemical reactor 5a, 5b, 5c can be optionally connected to the first or the second heat reservoir 2a, 2b. The temporary heat store 100 is installed in the arrangement 1 in such a way that the first partial store 101a fluidically communicates with the first heat reservoir 2a and the second partial store 101b fluidically communicates with the second heat reservoir 2b.
In the example in
In
The subsequent switching position of the first and the second valve devices is shown in
This unsteady temperature change process in the temporary heat store 100 has ended as soon as the heat transfer fluid F stratified up to temperature T1 in the temporary heat store 100 has been completely replaced by cooler heat transfer fluid stratified up to temperature T2 in the temporary heat store 100. Then, the second partial store 101b is completely filled and the first partial store 101a is empty. The illustration of
The next switching position of the first and the second valve devices 10a, 10b in accordance with
This state corresponds to the state according to
In the preceding explained example, the time-delayed switching of the first and the second valve devices 10a 10b take place in such a way that, at the same time, at least one of the sorption reactors 5a, 5b, 5c and a maximum of two of the available reactors 5a, 5b, 5c have the temperature level T1 of the first heat reservoir 2a. Thereby, it is possible to optimized the time allotments for the desorption and adsorption of each sorption reactor independent of the number of sorption reactors used.
Even in the case of the variant of the arrangement according to the invention with three thermochemical reactors described in the above based on
Number | Date | Country | Kind |
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102016215381.1 | Aug 2016 | DE | national |
This application claims priority to International Application PCT/EP2017/000982 filed on Aug. 16, 2017 and to German Application DE 10 2016 215 381.1 filed on Aug. 17, 2016, the contents of each are hereby incorporated by reference in their entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2017/000982 | 8/16/2017 | WO | 00 |