WO2012040864A1

WO2012040864A1 - Heat pump

Info

Publication number: WO2012040864A1
Application number: PCT/CH2011/000228
Authority: WO
Inventors: Erik Vincent Granwehr; Stefan Bertsch
Original assignee: Erik Vincent Granwehr; Stefan Bertsch
Priority date: 2010-09-29
Filing date: 2011-09-28
Publication date: 2012-04-05
Also published as: CH703290A1; EP2622289A1

Abstract

The invention relates to a heat pump 11 in which heat is fed in from the outside at at least two temperature levels. For this purpose, said heat pump has not only a compressor 13 for compressing a heat carrier, a first heat exchanger 19, an expansion stage 15 or 17 for relaxing the heat carrier and a second heat exchanger 21, but also a specific economizer 23 which can feed waste heat from outside the circuit to the heat carrier or to a part thereof.

Description

heat pump

Technical area

The invention relates to a heat pump according to the preamble of claim 1 and a method for its operation according to the preamble of claim 6.

State of the art

Heat pumps have been known for many years. It is about

Devices that absorb energy from a system of lower temperature by using labor and together with the

Drive energy transferred to a second system with higher temperature.

Normally this is done by using a heat transfer medium such as e.g. Propane is first compressed in a cyclic process, then releases heat to the outside via a first heat exchanger, then it is expanded and finally absorbs heat from outside in a second heat exchanger before it is again compressed. In the two heat exchangers usually takes place

Phase transition instead, which is why in the first heat exchanger also speaks of a condenser and the second heat exchanger of an evaporator. The compaction or the supply of the work takes place e.g. by means of a

Compressor, while the relaxation can be accomplished via an expansion valve or an expander.

At best, heat pumps are also known in which the release of heat to the outside takes place at two temperature levels (JP 60-226668, JP 60-126546). The heat transfer medium is in such facilities after passing through a

Compressor separated, wherein a part is further compressed to release heat via a condenser at a higher temperature level to the outside. Subsequently, the two parts are combined and used to give off heat at a lower temperature level, before the entire

CONFIRMATION COPY Heat transfer is relaxed to absorb in a well-known manner in an evaporator heat from the outside. Finally, the cycle begins again.

There are also known heat pumps with improved performance, in which the heat transfer medium is separated after passing through the first heat exchanger in a first and a second part. One of the two parts is relaxed and thus cools down. Subsequently, in a so-called economizer, he either exchanges heat with the other part or with the entire material flow, which comes from the first heat exchanger. The economizer is thus essentially a heat exchanger (cf., for example, WO 2008/105868 A2). The previously relaxed part is then bypassing the second

Heat exchanger fed back to the main flow, while the other part is expanded to an even lower pressure and then the second

Passes through heat exchanger. Thus, it is not necessary to depressurise the entire stream to the lower pressure and then to compress it again.

The publication US 2005/0132729 AI discloses a transcritical

Heat pump, the increased use of non-variable

Expansion valves allowed. In order to still be able to control the heat transfer flow through the system or the capacity, it is proposed to monitor and adjust the amount of heat transfer medium in the circuit. For this purpose, a collecting container with variable volume may be provided. Another possibility is the heating or cooling of the heat carrier. However, the temperature or the supplied energy must be adjustable as desired for the targeted adaptation of the heat transfer quantity. In addition, relatively large temperature gradients are necessary to ensure the necessary flexibility and to implement temperature changes quickly. The heat must therefore either by means of the described in US 2005 / 0132729A1 electrical

Heating elements are generated extra, which adversely affects the efficiency of the

Heat pump affects, or comes from the process itself and is by means of heat exchangers from streams at very high or low temperature branched off, as is also known from the prior art described above. An efficiency increase is not aimed at - on the contrary, the less expensive construction method is bought by a consumption of usable energy.

On abe of the invention

An object of the present invention is to provide a heat pump and a method of operating such which allow improved performance and / or efficiency over known heat pumps and known methods and / or reduce exergy losses. Further advantages and objects of the present invention will become apparent from the

following description.

Presentation of the invention

The above object is achieved according to the invention by a

Heat pump according to claim 1 and a method according to claim 6.

In particular, it is a heat pump with a

(preferably closed) circuit in which a heat transfer medium is guided, which heat pump has at least the following components:

- a compressor (or in general: one or more compressors) for

Compression of the heat carrier,

a first heat exchanger (preferably a condenser) located downstream of the compressor,

a first expansion stage and a second expansion stage for expansion (decompression) of the heat carrier or parts thereof, which are arranged downstream of the first heat exchanger, and

- A second heat exchanger (preferably an evaporator), which is arranged downstream of the second expansion stage and upstream of the compressor. In addition, the heat pump has a device (hereinafter also referred to as "economizer"), which the heat transfer medium or a part thereof (preferably the "second part", see below) heat from outside the

Can supply circulation. The device is for this purpose associated with a source of waste heat or is it in the heat that is supplied from outside the circuit to waste heat. The device is downstream of the first heat exchanger and upstream of the second

Heat exchanger arranged. The preferred sequence of the device components in the direction of flow of the heat carrier is therefore: 1) compressor, 2) first heat exchanger,

3) expansion stages and economizer, 4) second heat exchanger.

The economizer is arranged between the first and the second heat exchanger or the condenser and the evaporator and is designed such that it can supply heat to the heat carrier from outside the circuit. To this end, it advantageously has one or more heat exchangers associated with one or more sources of heat. By using waste heat from a process outside the cycle, the efficiency of the heat pump can be significantly increased. The

Temperatures of such waste heat sources can over a wide

Temperature range vary. The advantage lies in the fact that the waste heat can be supplied to the heat carrier at the temperature level or at that pressure level at which it is obtained.

The terms "upstream" and "downstream" refer to the direction of flow of the heat carrier. In the context of the method described below, terms such as "afterwards" or "then" are preferably defined as "later in time" and / or as "downstream" of the process. Advantageously, a method for operating a heat pump, in which a heat transfer medium is conducted in a (preferably closed) circuit, has at least the following steps (preferably in the predetermined sequence):

a) the heat carrier is compressed until a first pressure is reached, wherein individual parts of the heat carrier, e.g. can be compressed in a multi-stage compressor or separately from each other in several separate compressors;

b) the heat transfer medium is then removed from outside the circuit heat; this can e.g. take place in a capacitor, i. there can be a phase transition;

c) a first part of the heat carrier is expanded from the first pressure to a third (lower) pressure,

d) the first part of the heat carrier is then supplied at the third pressure heat from outside the circuit; this can e.g. take place in an evaporator, i. there can be a phase transition;

e) a second part of the heat carrier is expanded from the first pressure to a second (lower) pressure, the second pressure being higher than the third pressure; the second part can be relaxed either separately from the first part or together with the first part to the second pressure;

f) the second part of the heat carrier at the second pressure heat is supplied from outside the circuit, wherein the heat is waste heat from a process outside the circuit and either only the second part heat is supplied or - if the first and the second Part not yet been separated - the second and the first part together

Heat is supplied (the separation of the heat carrier in a first and a second part takes place in this case instead), and

g) the second part and the first part are merged thereafter. Embodiments of the mentioned heat pump and the method will be described below, wherein the said preferred features - insofar as they do not exclude - can be realized in any combination. The first, second and third pressures remain in relation to the above

Method preferably constant or substantially constant, while the heat transfer medium heat is supplied or withdrawn, in particular at step f). In addition, the heat supply can be optimized by regulation or control technology.

Advantageously, the heat transfer medium or a part thereof ("second part") in the economizer from outside the circuit heat to a medium

Temperature level and / or a medium pressure level supplied, i. at a temperature level and / or pressure level which is between that in the first heat exchanger and that in the second heat exchanger. This heat can be incurred, for example, in the form of waste heat and out

Solar systems, building ventilation, etc. come. This results in a

Performance improvement of about 10-20% compared to comparable heat pumps, because the heat is supplied to the heat transfer medium at the level or at the pressure level at which it is obtained.

The material cycle of the heat carrier is to be understood with advantage as "circulating." This preferably comprises at least the material flow (also referred to as "main flow") passing through the first heat exchanger and the second heat exchanger. Furthermore, it advantageously comprises at least one

Partial flow bypassing the second heat exchanger. The term "cycle" particularly preferably encompasses all material flows of the heat carrier which are circulated and are led together as a stream at least over part of the way mentioned material flows are circulated. If in this document of the supply of heat from outside the cycle is mentioned, it should preferably be understood that heat is supplied from outside the material cycle of the heat carrier. In other words, it is preferable to understand that not only an exchange of heat between partial flows of the heat carrier takes place, but at least one further source of heat is present. This heat source may be, for example, the engine that drives the compressor. However, in this document, among the sources of heat, particular preference is given to those sources which are not part of the heat pump. The supply of heat advantageously takes place downstream of the first

Heat exchanger and upstream of the second heat exchanger and / or upstream of a compressor instead.

The heat transfer medium is advantageously hydrocarbons such as propane (R-290), or propylene, or inorganic substances such as ammonia, carbon dioxide, or water. In addition to the aforementioned natural heat transfer and synthetic heat transfer medium such. Tetrafluoroethane (R-134a).

It may be preferred if the maximum pressure of the heat carrier in the

Circuit does not exceed 100 or 80 or 60 bar and the heat pump is designed for (or at most) such pressures. In the

Heat pump is preferably one which operates (in terms of the heat transfer medium) in the subcritical range and / or not to such a heat pump, which operates in the transcritical range. The first and / or second expansion stage is preferably an expansion valve or a condensate separator, in particular a thermodynamic condensate separator or a Sch wimmer valve. Especially with larger systems, the use of expanders may be advantageous in which the pressure loss is used to generate energy. Preferably, at least one expansion stage, in particular the second expansion stage, is variable and / or controllable (eg a variable expansion valve) The second expansion stage can also be a

Be a condensate separator or a float valve. Particularly preferably, both expansion stages are variable. With "variable" is in this context preferably the possibility of control or stepwise control

(in particular the heat transfer medium flow) meant, preferably by

Change in the opening width or the opening cross-section of the valve. The economizer preferably communicates with a source of heat, the source preferably being a source of waste heat and / or the source of heat in a temperature range between minus 20 ° C and plus 50 ° C, preferably between 0 ° C and plus 40 ° C and in particular between 10 ° C and 25 ° C, wherein the temperature or the

Temperature level is preferably substantially constant (difference between maximum and minimum preferably less than 15, 10 or 5 degrees Celsius). It may also be provided two, three, four or more of such sources, it being preferred if at least two sources are present, the heat in different temperature ranges provide, wherein the average temperature of the different temperature ranges preferably by at least 2, 5 or 10 degrees Celsius is different.

Accordingly, an above-mentioned method is preferable when

it is the heat generated at step f) (i.e., the second part of FIG

Heat carrier at the second pressure) is supplied to waste heat from a

Process outside the cycle (for example, from a solar system or a building ventilation) acts and / or if:

- The supply of heat in step f) (ie the second part at the second pressure) by contact of the heat carrier takes place with a surface which (especially before contact with the heat carrier) has a temperature between -20 ° C and plus 50 ° C, preferably between 0 ° C and plus 40 ° C and in particular between plus 10 ° C and plus 25 ° C and - as mentioned above - is preferably substantially constant.

A named method is furthermore advantageous if:

the supply of heat to the first part of the heat carrier according to step d) (i.e., the third pressure) takes place by contact of the first part of the heat carrier with a first surface,

- The supply of heat to the second part of the heat carrier according to step f) (i.e., the second pressure) by contact of the second part of the heat carrier takes place with a second surface, wherein

- The second surface has a higher temperature than the first surface, whereby preferably a pressure difference is produced.

The pressure of the heat carrier at the first surface is preferably at least 0.1 bar or at least 0.4 bar and more preferably at least 0.8 bar lower than at the second surface.

According to another preferred embodiment variant, the second

Surface have a temperature which is higher by at least 5 ° C, preferably at least 10 ° C and more preferably at least 15 ° C than the temperature of the first surface.

The surfaces mentioned are preferably surfaces of heat exchangers, the first surface preferably being part of the first

Heat exchanger is.

Furthermore, it is preferred if the economizer one or more

Having heat exchangers which are in communication with said sources of heat. Under the "temperature level" is then preferably the temperature of the medium or material flow to understand, which flows from the source coming through the heat exchanger and with the heat transfer of the Heat pump exchanges heat. The heat exchangers are advantageously designed so that the heat exchange takes place without mixing the material flows involved. According to a preferred embodiment, the economizer is a container for receiving the heat carrier, which has one (or more) heat exchanger, wherein the heat exchanger connected to a source (or in the case of several heat exchangers preferably with multiple sources) of heat outside the circuit is and is in contact with the heat transfer medium inside the container. The economizer can also act as a so-called collector ("receiver") here.

It has also proven to be advantageous to design the heat pump in several stages. For simplicity, the repetitive

Device parts of the individual stages collectively referred to as "module".

According to a preferred embodiment variant, the heat pump has a module which is arranged downstream of the first heat exchanger and has at least the following components:

- the economizer,

- the first expansion stage,

a branching point at which the heat transfer medium is separated into a first part and a second part,

- A first branch line for the first part of the heat carrier, which

is arranged downstream of the branching point,

a second branch line for the second part of the heat carrier, which downstream of the first expansion stage and downstream of the

Branch point is arranged

a supply line connected to the device, at least for the second part of the heat carrier (in the case of several modules, this may also be the first branch line of the preceding module). Advantageously, the module is arranged upstream of the compressor. Furthermore, it is advantageous if the module (at least with respect to the partial flow, which passes through the second heat exchanger, or with respect to the first part of

Heat carrier) upstream of the second expansion stage is arranged.

The preferred order of the device components in the direction of flow of the heat carrier (or at least the part stream passing through the second heat exchanger) is thus: 1) compressor, 2) first heat exchanger, 3) modules (including expansion stages and economizers), 4) second heat exchanger.

The separation of the heat carrier, i. the entire material flow, in a first part and a second part can thus take place at various points. According to an advantageous variant of the branch point is part of

Economizers or (with respect to the second branch line) arranged downstream of the device. This can e.g. then be the case when the economizer is designed as a container and the heat carrier is supplied to this total, but is discharged separately into a first and a second part.

Another embodiment variant provides that the branch point (with respect to the second branch line) is arranged upstream of the economizer. This can e.g. be the case when the second part of the heat carrier first passes through the economizer along with the first part and is then separated before it is again passed back into the economizer, there to exchange heat with the entire substance Ström the heat transfer medium.

The branch point may therefore be provided eg in the economizer or upstream or downstream thereof. At least the second branch line, which transports the second part of the heat carrier, is preferably arranged downstream of the first expansion stage. Thus, therefore, at least the second part of the heat carrier can be relaxed and thereby cool, before he heat in the economizer

(especially waste heat) from the outside absorbs. However, it is particularly preferred if both the first and the second branch line are arranged downstream of the first expansion stage and / or if the supply line

is arranged downstream of the first expansion stage or the first

Expansion stage is arranged in the supply line. In this way, both the first and the second part of the heat carrier (preferably together) relaxed and can absorb heat in the economizer from outside the circuit.

In this connection, a method mentioned above is particularly preferred when

- The first part of the heat carrier together with the second part of the

Heat carrier is relaxed from the first pressure to the second pressure, and

- After the first part of the heat carrier and the second part of the

Heat carrier is supplied together with the second pressure heat from outside the circuit, and

- The heat carrier is then separated into the first and the second part and the first part of the heat carrier is expanded from the second pressure to the third pressure. According to a particularly preferred embodiment variant, two, three or more modules are provided in the described heat pump, which are connected in series in the circuit, wherein the first branch line of a module feeds the subsequent heat transfer medium. This means that the first branch line of a preceding module preferably represents the supply line for the subsequent module. The "first part of the heat carrier" from the previous module in this case corresponds to the "first part" and the "Second part" of the heat carrier (ie, the total flow of the heat carrier) with respect to the subsequent module, so the modules are preferably

connected in series at least with respect to the main flow. Each module has an expansion stage ("first expansion stage"), resulting in pressure stages or temperature stages that can be used to supply heat from various external sources, especially in the case of larger systems, where a large number of modules is advantageous.

Accordingly, a named method may be advantageous if

a) the heat carrier is compressed until a first pressure (Pi) is reached, b) the heat transfer medium heat is then withdrawn from outside the circuit, c) a first part (Wi) of the heat carrier from the first pressure (Pi) to one third pressure (P3) is released,

d) the heat is then supplied to the first part (Wi) of the heat carrier at the third pressure (P3) from outside the circuit,

e) parts W2.1, W2.2 ... W2.N of the heat carrier are expanded from the first pressure (Pi) to the pressures P21, P2.2 ... PZN, where Pi> P2.1> P2. 2> ...> PZN> P3 is; f) the parts W2.1, W2.2 ... W2.N of the heat carrier at the pressures P2.i, P2.2 ... P2.N heat is supplied from outside the circuit, and

g) the parts W2.1, W2.2 .. · W ₂ .N of the heat carrier and the first part (Wi) are then combined.

Each part W ₂ .N is assigned a pressure PZN, on which the said part is relaxed (W2.1 is assigned to P2.1, W2.2 is assigned to P2.2, etc.). "N" is an integer, preferably between 2 and 20, in particular 2, 3, 4, 5, 6 or 7. Of course, here as well, the parts of the heat carrier can be expanded individually or jointly, as described above for the first and the second part The parts can then - as described below - take place an adaptation of the pressures. The parts W2.1, W2.2... W2.N are to be understood as design variants of the "second part" of the heat carrier described above, and the pressures P2.1, P2.2... P2.N are embodiments of the invention to understand the above-mentioned "second pressure". Accordingly, the features described in connection with the second part or the second pressure are also applicable to the design variants.

The second branch line advantageously opens upstream of the first

Heat exchanger and downstream of the second heat exchanger in the circuit and / or it opens into that portion of the circuit which carries the main flow between the first and the second heat exchanger. The second part of the heat carrier is thus preferred with circumvention of the second

Heat exchanger supplied to the first part of the heat carrier again. This can be done in different ways.

Advantageously, before the union of the first part with the second part of the heat carrier, an equalization of the pressures takes place, wherein the pressure of the first part can be increased and / or that of the second part can be reduced before the two parts are brought together. After unification, a further pressure increase can take place. It is particularly preferred to increase the pressure of the two parts separately from one another to different degrees in order to bring the pressures closer to one another. If more than one module is provided, the pressure equalization for the parts W2.1, W2.2 · .. WIN can be carried out analogously. Terms in this document should preferably be understood as one of ordinary skill in the art would understand. In particular in the event of ambiguity, the preferred definitions given in this document (alternative or supplementary) may be used. The terms "upstream" and "downstream" are preferably to one

Passage (a defined subset of the heat carrier) through the circuit based. This corresponds to the situation in which the cycle is (mentally) separated or opened at a reference point and interpreted as a linear process.

The term "waste heat" is preferably to be understood as meaning the heat which is generated by a device or a process but is not used and / or can not be used by the same device or in the same process. It could also be said that the waste heat reduces the efficiency of said device or of the said process and thus

Represents power loss. The said device or said process preferably serves not or not primarily for the generation of heat, but rather the heat is produced as a by-product or as a waste product, e.g. in the production of other products such as electricity, mechanical work, chemical or other products, etc. This includes, among other things, waste heat from machinery, power plants (photovoltaic systems, geothermal power plants, etc.) or living things (animals, humans, microorganisms, etc.) etc.

The heat pump can also be used for cooling because the external source of heat is cooled when heat is supplied to the economizer. The heat pump can thus e.g. be used for cooling water.

In general, the process referred to as process steps involves the use of one or more of those mentioned in this document

preferred features of the inventive device (or the functions enabled by these features) may include. Also, the heat pump may comprise means which can perform one or more of the process steps mentioned in the document.

It should be disclosed:

1. A heat pump with a circuit in which a heat transfer medium is performed, comprising

a compressor for compressing the heat carrier, a first heat exchanger, which is arranged downstream of the compressor,

a first expansion stage and a second expansion stage for expansion of the heat carrier or parts thereof, which downstream of the first

Heat exchanger are arranged

- A second heat exchanger, which downstream of the second

Expansion stage and upstream of the compressor is arranged, wherein the heat pump comprises a device which can supply the heat transfer medium or a part thereof heat from outside the circuit, wherein the device is arranged downstream of the first heat exchanger and upstream of the second heat exchanger.

2. A heat pump according to 1, wherein the device is a container for receiving the heat carrier, which has a heat exchanger, wherein the heat exchanger is connected to a source of heat outside the circuit and in contact with the heat transfer medium inside the container stands.

3. A heat pump according to 1 or 2, wherein the device communicates with a source of heat, wherein

- the source is a source of waste heat and / or

- The source of heat in a temperature range between minus 20 ° C and plus 50 ° C, preferably between 0 ° C and plus 40 ° C and in particular between 10 ° C and 25 ° C provides and / or

- That at least two sources are provided, which provide heat in different temperature ranges.

4. A heat pump according to any one of items 1 to 3, wherein the heat pump has a module which is arranged upstream of the second expansion stage and has at least the following components:

- the device, - the first expansion stage,

- A first branch line for the first part of the heat carrier, which

is arranged downstream of the branching point,

Branch point is arranged

- A connected to the device supply line, at least for the second part of the heat carrier.

5. A heat pump according to 4, wherein the branch point is part of the device or is located downstream of the device with respect to the second branch line.

6. A heat pump according to 4, wherein the branch point is located upstream of the device with respect to the second branch line.

7. A heat pump according to any one of items 4 to 6, characterized in that two, three or more modules are provided, which are connected in series in the circuit, wherein the first branch line of a module to a subsequent module supplies the heat carrier.

8. A heat pump according to any one of items 4 to 7, wherein the second

Branch line upstream of the first heat exchanger and downstream of the second heat exchanger opens into the circuit.

9. A method of operating a heat pump in which a heat transfer medium is circulated, wherein

a) the heat transfer medium is compressed until a first pressure is reached,

b) the heat transfer medium is then removed from outside the circulation heat, c) a first part of the heat carrier is expanded from the first pressure to a third pressure,

d) the third part of the heat transfer medium is then supplied with heat from outside the circulation,

e) a second part of the heat carrier is expanded from the first pressure to a second pressure, wherein the second pressure is higher than the third pressure, characterized

f) that the second part of the heat carrier at the second pressure heat from outside the circuit is supplied, and

g) that the second part and the first part are subsequently merged.

10. A method according to 9, which is characterized

- That the supply of heat to the first part of the heat carrier according to step d) by contact of the first part of the heat carrier takes place with a first surface,

- That the supply of heat to the second part of the heat carrier according to step f) takes place by contact of the second part of the heat carrier with a second surface,

- That the second surface has a higher temperature than the first surface, whereby a pressure difference is produced, and

- That the pressure of the heat carrier at the first surface by at least 0.1 bar, preferably at least 0.4 bar and more preferably at least 0.8 bar is lower than at the second surface. 11. A method according to any one of items 9 or 10, characterized

- That it is in the heat, which is supplied at step f) is waste heat from a process outside the circuit and / or

- That the supply of heat in step f) takes place by contact of the heat carrier with a surface having a temperature between minus 20 ° C and plus 50 ° C, preferably between 0 ° C and 40 ° C and

especially between 10 ° C and 25 ° C.

12. A method according to any one of items 9 to 11, which is characterized

distinguishes

- That the first part of the heat carrier is expanded together with the second part of the heat carrier from the first pressure to the second pressure, and

- that afterwards the first part of the heat carrier and the second part of the

Heat carrier together at the second pressure heat from outside the

Circulation is supplied, and

- That the heat transfer medium is then separated into the first and the second part and the first part of the heat carrier is expanded from the second pressure to the third pressure.

Brief description of the drawings

In a schematic, not true to scale representation:

Fig. 1 shows a refrigerator as known from the prior art;

Fig. 2 is a pressure-enthalpy diagram for a refrigerator according to

Figure V,

Fig. 3 shows an embodiment of the inventive heat pump

(open version with container);

A pressure-enthalpy diagram for a heat pump according to Figure 3;

5a shows an embodiment analogous to Figure 3, in which a part of

Heat transfer is compressed before the union with the rest of the heat carrier;

5b an embodiment analogous to Figure 3, in which a part of

Heat transfer is relaxed before the union with the rest of the heat carrier;

5c shows an embodiment analogous to FIG. 3 in which the two parts of FIG

Heat carrier separately compressed and then combined; and 5a-c show embodiments analogous to FIGS. 5a-c, wherein the branching point is arranged downstream of the economizer and the second part of the heat carrier is expanded a second time and then guided back into the economizer;

7 shows an embodiment of the inventive heat pump

(closed version);

8 shows a heat pump analogous to FIG. 3 in a multi-stage design; FIGS. 9a-c show different variants of the feed analogous to FIGS. 5a-c, but based on the closed embodiment according to FIG.

10 shows an application example in which an inventive

Heat pump is used as a building heating;

Embodiment of the invention

The invention will be explained by way of example with reference to the drawings.

Fig.l shows a heat pump as known from the prior art, while Figure 2 illustrates the process using a pressure-enthalpy diagram, wherein the circled numbers in Fig.l correspond to those in Figure 2. The machine shown in Fig.l is a cooling system as it is

For example, in WO 2008/105868 is described. A heat transfer medium or a coolant is compressed in a cyclic process, cooled, relaxed and reheated. The compression takes place by means of compressors 13, wherein the heat transfer medium simultaneously experiences a slight increase in the specific enthalpy due to the mechanical work performed by the compressor 13.

Subsequently, the heat transfer medium is passed through a condenser or generally a heat exchanger 19, where it releases heat to the outside and thus experiences a reduction of its specific enthalpy. The heat carrier is then passed through an economizer in the form of a heat exchanger 29, where its temperature is further lowered. For this purpose, a diverted part of the. By a reduction in pressure in a first expansion stage 15 is previously Heat carrier relaxed and thereby cooled before being passed in cocurrent through the heat exchanger 29, where he heat from the main stream

absorbs and increases its specific enthalpy. The main stream is decompressed in a second expansion stage 17 to a lower pressure and thus further cooled, before it can absorb heat in a second heat exchanger 21 from the outside and so cool the environment. The branched part is reunited after passing through the heat exchanger 29 with the rest of the heat carrier, the pressure has been previously increased by means of a compressor 13 accordingly. Subsequently, the heat carrier is again compressed, i. the cycle begins again.

3 shows an embodiment of the heat pump according to the invention and FIG. 4 illustrates the processes on the basis of a pressure-enthalpy diagram. The difference of this heat exchanger compared to that shown in Fig.l consists in the design of the economizer 23. The heat transfer medium is also supplied to the economizer 23 after the heat release in the first heat exchanger 19. This is done via a supply line 33, wherein the heat transfer medium, however, is previously relaxed in total in a first expansion stage 15 to a lower pressure and cools. In contrast to Fig.l the economizer 23 does not consist of a simple heat exchanger, but it has means that allow the supply of heat from outside the circuit. In the present case, this is a heat exchanger 25, which is the heat transfer medium e.g. Waste heat from other processes (solar systems / photovoltaic systems, building ventilation etc.) feeds. So it does not just find an exchange of heat within the

Cycle (i.e., between two streams of the cycle itself). Rather, the process sees the supply of heat from outside to two

different temperature levels, ie on the one hand - as known from the prior art - in the second heat exchanger 21, on the other hand, but also in the economizer 23, where preferably a supply of heat at a higher temperature level than in the second heat exchanger 21 takes place. 3 shows an open version of the heat pump 11, in which the economizer 23, the shape a container, in which the heat carrier is supplied in its entirety. The container shape allows the heat transfer medium to adjust its liquid volume to the temperature conditions. The economizer 23 thus provides space for the liquid part of the heat carrier to expand and contract (phase transition and volume change) and thus to assume a maximum and a minimum volume of liquid in the container. The heat exchanger 25 must be below a defined by the minimum volume of liquid

Fill level of the container to be arranged, while the container also at

Maximum volume of fluid should provide space for the heat transfer medium. A line 37 serves to branch off a gaseous part (second part) of the heat carrier from the economizer 23, this part due to its in the

Essential gaseous state has a higher specific enthalpy, as the economizer 23 through the line 35 extracted part (first part) of the heat carrier, which is substantially liquid. The latter flows through the line 35 to a second expansion stage 17, where it is further decompressed and thus cools before it is passed into the second heat exchanger 21 to receive there again heat from the outside. The two parts (first / second part) of the heat carrier are analogous to the example in Fig.l again

merged.

As can be seen from FIGS. 5a, 5b and 5c, the second part of the heat carrier, which leaves the economizer via the line 37, can be fed back to the circuit or the main flow of the heat carrier at different points downstream. Advantageously, before the union of the first part with the second part of the heat carrier, the pressures are equalized, whereby the pressure of the first part increases (FIG. 5a) and / or that of the second part can be reduced (FIG two parts are merged. After unification, a further pressure increase can take place. However, it is also possible to increase the pressure of both parts separately from each other to different degrees (Fig.5c) to approximate them. In Fig.5a, the first part and the second part of the heat carrier in the compressor 13th merged downstream of the second heat exchanger 21. In principle, this corresponds to the arrangement which is indicated by dashed lines, that is, the pressure in the first part of the heat carrier is in a first compressor 13 and a first before the merger of the two parts

Increased compression level. After the union of the two parts of the heat transfer medium by a second compressor 13 and a second

Compression stage further compacted before being passed into the first heat exchanger 19. Fig.5b shows a variant in which the second part of the heat carrier is withdrawn via the line 37 from the economizer 23 and then relaxed. The line 37 opens downstream of the second

Heat exchanger 21 in the circuit and the second part of the heat carrier after passing through an expansion stage (for example, expansion valve or expander) to the first part of the heat carrier to. Subsequently, the heat carrier is compressed in a compressor 13 before it is fed to the first heat exchanger 19. Fig.5c describes an embodiment in which the first part and the second part of the heat carrier separately from each other through a compressor 13, wherein the second part must be less compressed, since its pressure is higher because it does not pass the second expansion stage 17 Has. The merging of the two parts of the heat carrier takes place downstream of the two compressors 13 and before entry into the first heat exchanger 19.

6a to 6c show an embodiment of the heat pump 11, in which the heat carrier is supplied to the economizer 23 in total via the supply line 33, after it has been expanded in the first expansion stage 15. in the

Economizer 23 takes the heat transfer heat through the heat exchanger 25 from outside the circuit. The branching point 34, ie the location at which the heat transfer medium is divided into two streams (first / second part), does not lie here in the economizer 23, but downstream thereof. From there, the second part of a further expansion stage 16 is supplied, cools and is then supplied via the branch line 37 to the economizer 23, where he heat via a heat exchanger 29 with the line 33 supplied total flow of the heat carrier exchanges. That is, the second part passes through the economizer 23 twice per cycle. On the one hand, together with the first part as the total flow of the

Heat carrier and a second time as a separate stream to exchange heat via a heat exchanger 29 with the total heat. Analogous to FIGS. 5 a to 5 c, FIGS. 6 a to 6 c show different variants of how the first and the second part of the heat carrier downstream of the second heat exchanger 21 can be combined. The essential advantage of the embodiments according to FIGS. 6 a to 6 c compared to those from FIGS. 5 a to 5 c lies in the oil guide. Because the second part of the heat carrier leaves the economizer 23 here in the liquid state. Thus, a lubricant entrained in the heat transfer medium (for example oil) remains in the heat transfer medium and stands for the lubrication of the lubricant

Compressor 13 available. In contrast, in the examples according to FIGS. 5 a to 5 c, the evaporation of the heat carrier in FIG

Economizer held a separation.

FIG. 7 shows a closed version of the heat pump 11

Economizer 23 is not formed here in the form of a container, but as two (preferably separate) heat exchangers 25 and 29. The one heat exchanger 29 performs the function of an economizer as it is known from the prior art. The other heat exchanger 25 supplies heat to the second part of the heat carrier from outside the circuit. Of the

Branching point 34 is here, in contrast to Fig.6a to 6c upstream of the economizer 23 (ie, with respect to both branch lines 35 and 37). From there, the second part of the heat carrier of the first expansion stage 15 is supplied, cools and is then supplied via the second branch line 37 to the economizer 23, where it exchanges heat via a heat exchanger 29 with the first branch line 35 supplied to the first part of the heat carrier. After passing through the heat exchanger 29, the supply of heat to the second part of the heat carrier takes place by means of a heat exchanger 25. FIG. 8 illustrates a heat pump having a plurality of repeating units, referred to as modules 24. A module 24 is indicated by a dashed line. All modules 24 are in relation to the

Main current upstream of the second expansion stage 17 is arranged (although it is also conceivable that each module has a second expansion stage 17) and each module 24 each has an economizer 23, and a first expansion stage 15 on. Furthermore, a branch point 34 is present per module 24 (here within the container-shaped economizer 23), at which the heat carrier is separated into a first part and a second part, and a first

Branch line 35 for the first part of the heat carrier, which is arranged downstream of the branch point 34 and a second branch line 37 for the second part of the heat carrier, which downstream of the first expansion stage 15 and downstream of the branch point 34 is arranged. In addition, for each module 24 there is provided a line (depending on the design 33 or 37, here 33) connected to the economizer 23, which feeds the economizer 23 at least the second part of the heat carrier. Said line (33 or 37) is arranged downstream of the first expansion stage 15, because at least the relaxed and thus cooled second part of the heat carrier is in the

Economizer 23 directed to receive there heat from sources outside the circuit, here via the heat exchanger 25. If the total flow of the heat carrier in the first expansion stage 15 is relaxed before it is passed into the economizer 23, the said conduit corresponds to the supply line 33rd (see Figures 3, 5a to 5c, 8, 10 and 11). However, if a separation of the heat carrier takes place before the expansion in the first expansion stage 15, with only the second part of the heat carrier passing through the first expansion stage 15, then said line corresponds to the branch line 37 (FIGS. 7 and 9a to 9c). The economizer 23 of the first module 24, which downstream of the first

Heat exchanger 19 is arranged flows in the multi-stage model shown by its supply line 33 (depending on the configuration of the economizer 23)

optionally still the total flow of the heat carrier. Since in each module a here as "second part" designated portion of the heat carrier via a Branch line 37 is disconnected, the current of the heat carrier naturally decreases. The supply line 33 of the subsequent stage transports only the portion of the heat transfer medium referred to here as the "first part"

previous module. In other words, the supply line 33 of the respective subsequent module corresponds to the branch line 35 of the preceding

Module 24 or goes into this. In each module, heat is supplied via one or more heat exchangers 25, preferably at different temperatures

Temperature levels. The discharged "second parts" of the heat carrier leave the respective modules 24 with advantage at different pressures

Heat pump 11 can dissipate the accumulated heat from other processes, i.

for example, waste heat from different sources, on the appropriate

Temperature level or pressure level are supplied.

FIGS. 9a to 9c show, analogously to FIGS. 5a to 5c, different variants of how the first and the second part of the heat transfer medium can be combined, the basis being a heat pump according to FIG.

10 shows an application example in which the heat pump 11 is used in a building. The heat pump 11 largely corresponds to that shown in Figure 3, although only one compressor 13 is used in the present example. It serves to heat the building via a space heater 19 using waste heat from other processes. On the one hand, this is the waste heat from a solar collector 55 and on the other hand, that from a controlled apartment ventilation 57. The solar collector 55 and the

Apartment ventilation 57 are each in contact with a heat exchanger 25 and 27, which are arranged in the economizer 23 and there heat the heat transfer medium. The heat transfer medium thus passes through the compressor 13, then gives off heat in the controlled domestic ventilation 57 and subsequently in a space heater 19 before it enters the economizer 23. There it is - as described above - waste heat from a solar collector 55 and the controlled ventilation ventilation 57 supplied. Subsequently, a first part of the heat carrier withdrawn via the line 35 from the economizer 23, in an expansion valve 17 relaxed (where it cools) and takes on the other side of the building wall 61 in a heat exchanger 21 (condenser) heat from the environment. A second part leaves the economizer 23 via the line 37 and is combined in the region of the compressor 13 with the first part. As can be seen from Fig. 10, the heat in addition to the operation of a

Water storage 59 can be used.

List of reference numbers:

11 heat pump

13 compressor

15 first expansion stage / first expansion valve

16 expansion stage / expansion valve

1 second expansion stage / second expansion valve

19 first heat exchanger / condenser / space heating

21 second heat exchanger / evaporator

23 Device for the supply of heat / economizer

24 module

25 heat exchangers (heat supply from outside)

27 heat exchanger (heat supply from outside)

29 heat exchanger (heat exchange between partial flows)

33 Supply line for the heat transfer medium

34 branch point

35 first branch line for the first part of the heat carrier / discharge

37 second branch line for the second part of the heat carrier / discharge 51 heat exchanger

53 heat exchangers

55 Source of waste heat / solar collector

57 Source of waste heat / Controlled domestic ventilation

58 Source of waste heat / motor to drive the compressor

59 storage tank / hot water tank

61 building wall

Claims

claims

1. heat pump (11) with a circuit in which a heat transfer medium is performed, comprising

a compressor (13) for compressing the heat carrier,

a first heat exchanger (19), which is arranged downstream of the compressor (13),

- A first expansion stage (15) and a second expansion stage (17) for

Relaxation of the heat carrier or parts thereof, which are arranged downstream of the first heat exchanger (19),

- A second heat exchanger (21), which downstream of the second

Expansion stage (17) and upstream of the compressor (13) is arranged, characterized in that

- The heat pump (11) comprises a device (23) which can supply the heat transfer medium or a part thereof heat from outside the circuit, wherein the device (23) for this purpose with a source of waste heat (55, 57) is in communication and

- The device (23) downstream of the first heat exchanger (19) and upstream of the second heat exchanger (19) is arranged.

2. Heat pump according to claim 1, characterized in that it is in the device (23) is a container for receiving the heat carrier, which has a heat exchanger (25,27), wherein the heat exchanger (25,27) with the source of Waste heat (55,57) is connected outside the circuit and is in contact with the heat carrier inside the container (23).

3. Heat pump according to claim 1 or 2, characterized in that the source (55,57) provides heat in a temperature range between minus 20 ° C and plus 50 ° C.

4. Heat pump according to claim 3, characterized in that the source (55,57) provides heat in a temperature range between 10 ° C and 25 ° C.

5. Heat pump according to one of claims 1 to 4, characterized in that at least two sources (55,57) are provided, the heat in

deliver different temperature ranges.

6. A method for operating a heat pump in which a heat transfer medium is circulated, wherein

a) the heat transfer medium is compressed until a first pressure is reached,

b) heat is then withdrawn from the outside of the circuit, c) a first part of the heat carrier is expanded from the first pressure to a third pressure,

e) a second part of the heat carrier is expanded from the first pressure to a second pressure, the second pressure being higher than the third pressure,

characterized,

f) that the second part of the heat carrier at the second pressure heat from outside the circuit is supplied, wherein the heat to

Waste heat from a process outside the cycle is and

g) that the second part and the first part are subsequently merged.

7. The method according to claim 6, characterized

- That the supply of heat to the first part of the heat carrier according to step d) by contact of the first part of the heat carrier with a first

Surface takes place,

- That the supply of heat to the second part of the heat carrier according to step f) takes place by contact of the second part of the heat carrier with a second surface, - That the second surface has a higher temperature than the first

Surface, whereby a pressure difference is produced, and

- That the pressure of the heat carrier at the first surface by at least 0.1 bar, preferably at least 0.4 bar and more preferably at least 0.8 bar is lower than at the second surface.

8. The method according to any one of claims 6 or 7, characterized in that the supply of heat in step f) is effected by contact of the heat carrier with a surface having a temperature which is between minus 20 ° C and plus 50 ° C.

9. The method according to claim 8, characterized in that the surface has a temperature which is between 10 ° C and 25 ° C.

10. The method according to any one of claims 6 to 9, characterized

- That thereafter the first part of the heat carrier and the second part of the heat carrier is supplied together with the second pressure heat from outside the circuit, and