WO2011023352A2

WO2011023352A2 - Heat pump

Info

Publication number: WO2011023352A2
Application number: PCT/EP2010/005153
Authority: WO
Inventors: Karsten Uitz
Original assignee: Karsten Uitz
Priority date: 2009-08-31
Filing date: 2010-08-23
Publication date: 2011-03-03
Also published as: WO2011023352A3; EP2473795A2; DE102009039326A1

Abstract

The invention relates to a heat pump (1) having a first heat pump circuit (2), which comprises an input heat exchanger (4) and an output heat exchanger (8), wherein there is a primary medium from a heat source flowing through the input heat exchanger (4) in the operating state and, on the secondary side, said medium is designed to evaporate a heat pump circuit medium which flows through the first heat pump circuit (2). According to the invention, a compressor unit (6) compresses evaporated heat pump circuit medium, wherein there is a feed means, through which the compressed heat pump circuit medium can be fed to the output heat exchanger (8), and there is a secondary medium flowing through the secondary side of the output heat exchanger (8) in the operating state, said medium being at a higher temperature than the primary medium. According to the invention, the heat pump (1) comprises at least one second heat pump circuit (3) having an input heat exchanger (4) and an output heat exchanger (8), wherein the primary sides of the input heat exchangers (4) of the first and second heat pump circuit (2, 3), and the secondary sides of the output heat exchangers (8) of the first and second heat pump circuit (2, 3) in each case are connected in series.

Description

"Heat pump"

The invention relates to a heat pump according to the preamble of claim 1.

State of the art:

With a heat pump is under supply of work the

Temperature of a medium of a given

Temperature level raised to a higher temperature level. The ratio of usable heat output to supplied, for example, electrical power is called coefficient of performance in the literature as COP "Coefficient Of Performance".

Object and advantages of the invention:

The invention has for its object to provide a heat pump, which has a relatively high COP value.

This object is solved by the features of claim 1.

In the dependent claims advantageous and expedient developments of the invention are given.

The invention is based on a heat pump with a first heat pump circuit comprising an inlet heat exchanger and an outlet heat exchanger. The input heat exchanger is in the working state of a primary medium of a heat source flows through. The primary medium can be liquid or gaseous. On the secondary side, the input heat exchanger is designed for the evaporation of a heat pump circuit medium, which flows through the first heat pump circuit. In addition, a compressor unit is provided, the vaporized

Heat pump circuit medium compacted, wherein supply means

are present, over which compacted

Heat pump circuit medium can be supplied to the output heat exchanger. The output heat exchanger can as

Condenser heat exchanger may be formed. The secondary side of the output heat exchanger is flowed through in the working state of a secondary medium which has a higher temperature than the primary medium.

The essence of the invention lies in the fact that the heat pump comprises at least a second heat pump cycle, with an input heat exchanger and an output heat exchanger, wherein the input heat exchanger of the first and second

Heat pump circuits primary side and the output heat exchanger of the first and second heat pump circuit are connected on the secondary side in each case in series. This will be the

Primary sides of the input heat exchanger of primary medium and the secondary sides of the output heat exchanger of

Secondary medium flows through in series.

By using at least a second one

Heat pump cycle, the COP value improves significantly, since the workload in the compression of

Heat pump circuit medium for both circuits is less than half of the workload of a single-circuit heat pump, assuming equal temperature levels.

In a preferred embodiment of the invention is the

Heat pump designed so that in working condition on the

Input heat exchanger together the temperature difference of a flow and return of the primary medium completely drops. The heat input into the heat pump takes place accordingly

exclusively via the series-connected primary sides of the input heat exchangers. In this context, it is also preferred if the heat pump is designed such that over the

Output heat exchanger together a desired

Temperature difference of the output medium drops. In this case, the desired temperature difference thus becomes

solely by the temperature drop in series

switched secondary sides of the output heat exchanger

provided .

Due to the structure of the heat pump according to the invention, the heat pump can be designed such that with a

Primary medium can be worked, the flow temperature is above 40 ⁰ C, without achieving a comparatively poor COP.

Accordingly, it is possible both to design the heat pump that can be used with a secondary medium, which can be raised to a temperature which is above 95 ° C, in particular 100 ⁰ C.

In a further preferred embodiment of the invention, the heat pump circuit medium of the first and second

Heat pump circuits different. Thus, for the first and second optionally a further heat pump circuit optimized for the respective work area refrigerant

be used, thereby increasing the efficiency of

Heat pump further improved.

Preferably, the second and optionally each further heat pump cycle of the basic structure is constructed as the first heat pump cycle, i. with a

Inlet heat exchanger, in particular an evaporator inlet heat exchanger and an outlet heat exchanger,

in particular a condenser outlet heat exchanger and a compressor unit. In addition, an additional heat exchanger can be provided, which heats the evaporated, to be compressed medium in countercurrent, at the same time before the back flowing from the output heat exchanger medium the evaporation is cooled. Also by this measure, the efficiency of the heat pump can be further improved.

In a further advantageous embodiment of the

Invention is at least a third heat pump cycle

formed, wherein the input heat pumps of the

Heat pump circuits primary side and the output heat pumps of the heat pump circuits are connected on the secondary side in each case in series.

This can be dependent on a given

Temperature level, from which is expected or to be raised to bring about a further improvement in the COP value.

Drawings:

An embodiment of the invention is illustrated in the drawing and will be given below stating more

Advantages and details explained in more detail.

The figure shows a schematic structure of a

heat pump according to the invention.

Description of the embodiment:

In the figure, a heat pump 1 is shown in a schematic block diagram, in which two heat pump circuits 2, 3 are coupled together. For improved illustration, the heat pump circuits 2, 3 of a solid

Surrounded by a box.

The first heat pump cycle 2 includes a

Evaporator 4, a countercurrent heat exchanger 5, a plurality of compressor 6 between eg shut-off valves 7, a Kondensatorenausgangswärmetauscher 8, a collection unit 9, a filter dryer 10 and an injection valve 11. In addition, as shown in the figure by way of example, a sight glass 12 and a further shut-off valve 13 is provided be. The heat exchangers 4, 8 each have a primary side 4a, 8a and a secondary side 4b, 8b.

The listed components are over various lines

interconnected with 14a and 14b the

Supply line or the return line for a primary medium of a heat source and 15a and 15b, the flow line and the return line of a secondary medium are designated.

The heat pump 1 according to the invention operates according to the following principle:

First, the first heat pump cycle 2 is picked out.

A primary medium is supplied via the flow line 14a with e.g. a temperature of 43.5 ° C in the primary side 4a of

Evaporator inlet heat exchanger 4 initiated. As a result, evaporate on the secondary side 4b of the evaporator input heat exchanger 4 refrigerant, whereby about half of the amount of heat to be removed, the

Primary medium is withdrawn. This cools that

Primary medium by about half of the specified

Temperature difference between flow and return from. The reflux of the primary medium may e.g. have a temperature of 39 ° C.

Since only half of the intended temperature difference drops, a correspondingly high

Evaporator temperature and thus a high evaporation pressure in the evaporator of the evaporator input heat exchanger 4 a. This favors a good COP value. The evaporated refrigerant flows through the additional

Countercurrent heat exchanger 5, which in countercurrent of

liquefied refrigerant is flowed through, whereby the refrigerant coming from the evaporator further heated. This additionally increases the COP value of the heat exchanger 1. Im

Counter flow heat exchanger 5, the liquid refrigerant is further cooled down, which also has a COP value improvement result. The vaporized and heated refrigerant is by means of the compressor 6 to a desired condensing pressure;

compressed. This is the largest share of a

Compressor work and a compressor motor heat the

Supplied refrigerant. The high pressure

Refrigerant is the condenser heat exchanger 8 of the first heat pump circuit 2, for example, supplied with a temperature of about 100 ⁰ C. In the condenser heat exchanger 8, a predetermined amount is delivered to a heat sink 20. This is the

Secondary side 8b of the capacitor output heat exchanger 8 flows through a secondary medium via the feed line 15a. Preheated by the output heat exchanger 8 of the second heat pump circuit 3 secondary medium is thereby brought to a predetermined target temperature.

The secondary medium flows to reach the target temperature of the output heat exchanger 8 of the second heat pump cycle 3 via a connecting line 16 in the secondary side

Input of the output heat exchanger 8 of the first

Heat pump circuit 2.

Condensed and cooled refrigerant from the

Outgoing heat exchanger 8 flows into the collecting unit 9. From there it is guided through the filter drier 10, the sight glass 12 and the countercurrent heat exchanger 5 to the injection valve 11. The injection valve 11 acts as a throttle member and lowers the refrigerant pressure to a desired

Evaporation pressure. In the input heat exchanger can

Refrigerant again absorb heat from the primary medium and the heat pump cycle begins again.

The evaporator of the evaporator input heat exchanger of the second heat pump circuit 3 extracts the primary medium approximately the second half of the amount of heat that is to be withdrawn. As a result, the primary medium cools by about half of the predetermined temperature difference. In terms of numbers, this can look like this: The flow of the primary medium has a temperature of, for example, 43.5 ° C, at the exit from the evaporator inlet heat exchanger 8 of the first heat pump cycle 2, the temperature is

41,25 ⁰ C. The primary medium is introduced at this temperature via a connecting line 17 in the evaporator inlet heat exchanger 4 of the second heat pump circuit 3 and that from the evaporator inlet heat exchanger 4 of the second

Heat pump circuit 3 discharged primary medium is e.g. cooled to 39 ° C.

In the second heat pump cycle 3, the primary medium is cooled by half the predetermined temperature difference. The vaporized refrigerant then flows through the

additional heat exchanger 5, which is flowed through in countercurrent by the liquefied refrigerant and thus the refrigerant coming from the evaporator is further heated. This increases, as already mentioned above, the COP value in addition. At the same time, the liquid refrigerant will continue

cooled down, which also, as mentioned above, improves the COP value. The vaporized and heated refrigerant is by means of the compressor 6 to the desired

Condensing pressure compressed. In this case, as in the first heat pump cycle 2, the largest portion of a compressor work and a compressor engine waste heat is supplied to the refrigerant. The under elevated pressure refrigerant is the

Condenser heat exchanger 8 of the second heat pump circuit 3 is supplied. Here is the intended amount of heat to the

Delivered secondary medium. The secondary medium in this process is only half of the desired

Total temperature increase heated. This means one

reduced condensation temperature, and thus one

reduced condensation pressure, which causes a further increase in the COP value. The further process corresponds to that of the first heat pump cycle. 2

In the secondary medium, the amount of heat given off corresponds approximately to the heat absorbed by the primary medium

plus the recorded compressor work as well

Compressor engine waste heat. In contrast to conventional heat pump systems, which are normally limited to a maximum temperature of 75 ° C, can be achieved by the system according to the invention temperatures in the secondary medium of about 100 ⁰ C, with a comparatively high COP value. In principle, this is achieved in that the medium to be heated flows through two heat exchangers in succession, the input heat exchanger of the first heat pump cycle and then the input heat exchanger of the second heat pump cycle. For example, divided in half dissipated heat amounts are then in the respective

Heat pump circuit set to a predetermined temperature high, whereby the distribution of the amount of heat and the

Divide temperature differences, z. For example, it can be halved, which is crucial for the efficiency of the system.

In the figure, the feed line 15a for a heat sink is guided on a mixer 18, the heated secondary medium of the secondary medium in the return line 15b for a desired

Temperature setting admixed. This is not

absolutely necessary.

A required volume flow is e.g. by a

Buffer loading pump 19 is provided.

List of reference numbers:

1 heat pump

2 heat pump circuit

3 heat pump circuit

4 evaporator inlet exchanger 4a primary side

4b secondary side

5 countercurrent heat exchanger

6 compressors

7 shut-off valve

8 Condenser output heat exchanger 8a primary side

8b secondary side

9 collection unit

10 filter driers

11 injection valve

12 sight glass

13 shut-off valve

14a supply line

14b return line

15a supply line

15b return line

16 connection line

17 connection line

18 mixers

19 Buffer loading pump

20 heat sink

Claims

Claims :

1. heat pump (1) with a first heat pump circuit (2) having an input heat exchanger (4) and a

Output heat exchanger (8), wherein the

Input heat exchanger (4) in the working state of a

Primary medium of a heat source is flowed through and

Secondary side is designed for the evaporation of a heat pump circuit medium, the first heat pump cycle (2)

is provided, wherein a compressor unit (6) is provided which compresses vaporized heat pump circuit medium, wherein supply means are present, via which compacted

Heat pump circuit medium, the output heat exchanger (8) can be supplied and wherein the secondary side of

Output heat exchanger (8) in the working state of a

Secondary medium is flowed through, which has a higher temperature than the primary medium, characterized in that the heat pump (1) comprises at least a second heat pump circuit (3), with an input heat exchanger (4) and a

Output heat exchanger (8), wherein the input heat exchanger (4) of the first and second heat pump circuit (2), (3)

primary side and the output heat exchanger (8) of the first and second heat pump circuit (2), (3) are each connected in series on the secondary side.

2. Heat pump according to claim 1, characterized in that the heat pump is designed such that in the working state via the input heat exchanger (4) together drops a predetermined temperature difference of a flow and return of the primary medium.

3. Heat exchanger according to one of the preceding claims, characterized in that the heat pump (1) in such a way

is designed so that via the output heat exchanger (8)

together a predetermined temperature difference of

Secondary medium drops.

4. Heat pump according to one of the preceding claims, characterized in that the heat pump (1) is designed to work with a primary medium whose flow temperature is above 4O ⁰ C.

5. Heat pump according to one of the preceding claims, characterized in that the heat pump (1) is designed to work with a secondary medium whose temperature is above 95 ° C.

6. Heat pump according to one of the preceding claims, characterized in that the heat pump circuit medium of the first and second heat pump circuits (2), (3) is different.

7. Heat pump according to one of the preceding claims, characterized in that at least a third

Heat pump circuit is formed, wherein the

Input heat pumps of the heat pump circuits on the primary side and the output heat pumps of the heat pump circuits are connected on the secondary side in each case in series.

8. Heat pumps according to one of the preceding claims, characterized in that the second or each further heat pump cycle, the basic structure of the first

Heat pump circuit (2) has.