Device and Method for Increasing the Heat Yield of a Heat Source

Abstract

Various embodiments include a device for increasing the heat yield of a heat source comprising: a heat sink; a heat pump with a condenser and an evaporator; and a heat sink feed and a heat sink return providing a thermal coupling to the heat source with a heat exchanger. The condenser is thermally coupled to the heat sink feed for emitting heat to the heat sink. The evaporator is thermally coupled to the heat sink return for absorbing heat.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application of International Application No. PCT/EP2018/061001 filed Apr. 30, 2018, which designates the United States of America, and claims priority to DE Application No. 10 2017 208 079.5 filed May 12, 2017, the contents of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to thermal management systems. Various embodiments may include devices and/or methods for increasing the heat yield of a heat source in a thermal management system.

BACKGROUND

Waste heat from industrial processes or heat from geothermal sources is often used to provide heat for a heat consumer, i.e. emit this to a heat sink. The heat is typically transmitted to the heat sink by means of a heat transmitter or an additional heat pump. If the heat provided by a heat source is transmitted to the heat sink by means of a heat exchanger, the heat sink typically has a heat sink return and a heat sink feed for a fluid in connection with said heat exchanger. Here, the heat sink return has a lower temperature than the heat sink feed. In other words, at least some of the heat is consumed by the heat sink.

Similarly, the heat source typically has a heat source return and a heat source feed in connection with the heat exchanger. Here, the temperature of the heat source feed is greater than the temperature of the heat source return because of the transmission of heat by means of the heat exchanger. Because of the thermal coupling of the heat source to the heat sink by means of the heat exchanger, the temperature of the heat source return is restricted by the temperature of the heat sink return. In other words, the temperature of the heat source return cannot be lowered further if heat is to be transmitted to the heat sink.

Furthermore, the temperature of the heat sink feed is restricted by the temperature of the heat source feed. Said restrictions lead to the disadvantage that the heat content of the heat source cannot be fully utilized. In other words, the heat yield of the heat source is thereby restricted.

SUMMARY

The present disclosure provides teachings useful for improving the heat yield of a heat source. For example, some embodiments include a device (1) for increasing the heat yield of a heat source (6), comprising: a heat sink (2) and a heat pump (4) with a condenser (41) and an evaporator (42); wherein the heat sink (2) has a heat sink feed (21) and a heat sink return (22) in connection with a thermal coupling to the heat source (6) by means of a heat exchanger (12); and the condenser (41) of the heat pump (4) is thermally coupled to the heat sink feed (21) for emitting heat to the heat sink (2); characterized in that the evaporator (42) of the heat pump (4) is thermally coupled to the heat sink return (22) for absorbing heat.

In some embodiments, the device comprises the heat source (6), wherein after the evaporator (42) of the heat pump (4), the heat sink return (22) is thermally coupled to the heat source (6) by means of the heat exchanger (12) for absorbing heat.

In some embodiments, the condenser (41) of the heat pump (4) is thermally coupled to the heat sink return (22) by means of a bypass line (23).

In some embodiments, the heat sink (2) is part of a district heating network.

In some embodiments, the heat source (6) is a geothermal source and/or an industrial waste heat source.

In some embodiments, the heat pump (4) is configured as a high-temperature heat pump.

In some embodiments, the heat pump (4) comprises a working fluid with R1233zd, R1336mzz, butane, cyclopentane and/or with a fluoroketone and/or a mixture of said substances.

In some embodiments, the heat pump (4) has an electrical power of at least one Megawatt.

As another example, some embodiments include a method for increasing the heat yield of a heat source (6) with a device as claimed in any of the preceding claims, comprising the steps: heat transmission from the heat source (6) to the heat sink return (22) by means of the heat exchanger (12); heat transmission from the condenser (41) of the heat pump (4) to the heat sink feed (21); and characterized by a heat transmission from the heat sink return (22) to the evaporator (42) of the heat pump.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features, and details of the teachings herein are illustrated in light of the exemplary embodiments described below and from the drawings. These show diagrammatically:

FIG. 1 a yield of the heat source by means of a heat pump according to the prior art;

FIG. 2 a device incorporating teachings of the present disclosure; and

FIG. 3 a device incorporating teachings of the present disclosure.

Similar or equivalent elements, or those with the same function, may carry the same reference signs in the figures.

DETAILED DESCRIPTION

In some embodiments, a device for increasing the heat yield of a heat source comprises at least:

• • a heat sink and a heat pump with a condenser and an evaporator; wherein
  • the heat sink has a heat sink feed and a heat sink return in connection with a thermal coupling to the heat source by means of a heat exchanger; and
  • the condenser of the heat pump is thermally coupled to the heat sink feed for emitting heat to the heat sink and the evaporator of the heat pump is thermally coupled to the heat sink return for absorbing heat.

In some embodiments, the heat sink feed and the heat sink return form a heat sink circuit for a fluid, wherein the fluid of the heat sink return is heated at least by the heat exchanger. After heating by the heat exchanger, the heat sink return becomes the heat sink feed. Thus, the heat sink feed has a higher temperature than the temperature of the heat sink return.

The heat source feed and the heat source return may form a heat source circuit for a fluid, wherein the fluid of the heat source feed is cooled at least by means of the heat exchanger and its heat transmitted at least partially to the heat sink return for forming the heat sink feed. After cooling of the heat source feed by the heat exchanger, the heat source feed becomes the heat source return. The heat source return may alternatively or additionally be diverted partially or completely and thus not be returned partially or completely to the heat source.

Relative arrangements, for example the arrangement of one element immediately before or immediately after a further element of the device, refer to a direction of a circuit and/or a flow direction of a fluid, for example to a direction of a heat sink circuit. The heat sink circuit is formed by means of the heat sink feed and the heat sink return.

In some embodiments, the evaporator, which is thermally coupled to the heat sink return, allows a reduction in the temperature of the heat sink return. Thus, the heat source is further cooled so the heat yield is increased. For this, the evaporator may be not in direct contact with the heat source. In this way, the evaporator may be fitted later to existing systems without making apparatus changes to the heat source.

The heat extracted from the heat sink return by means of the evaporator is transmitted to the heat sink feed by means of the condenser of the heat pump. In this way, the use of the heat content of the heat source can be improved and hence more heat or a higher thermal output or a higher temperature for the heat sink can be provided. In other words, by including the heat pump in the heat sink circuit as taught herein, the heat sink return is cooled further and the heat sink feed heated further.

With an industrial waste heat source (heat source), the heat source return according to the prior art must be cooled by means of cooling devices, in particular cooling towers, before it can be discharged for example as a wastewater stream. With the further cooling of the heat sink return taught herein, accordingly the heat source return is cooled more greatly so that complex and cost-intensive cooling devices for cooling the heat source return may be omitted. In addition, the temperature of the heat sink feed may be increased by means of the condenser of the heat pump. In this way, the use of the heat content of the waste heat source is improved.

With a geothermal source (geothermal heat source), the heat source return is cooled more greatly so that its heat yield is improved. Furthermore, there is a prospecting risk for geothermal sources. This risk arises from the fact that the temperature and potential mass flow of the thermal water from the borehole cannot be predicted with sufficient reliability. The teachings of the present disclosure may therefore significantly reduce said risk or avoid the conclusion of costly insurance policies.

In some embodiments, a method for increasing the heat yield of a heat source with a device as taught herein or one of its embodiments comprises at least the following steps:

• • heat transmission from the heat source to the heat sink return by means of the heat exchanger;
  • heat transmission from the condenser of the heat pump to the heat sink feed;
    characterized by a heat transmission from the heat sink return to the evaporator of the heat pump.

The methods described provide similar and equivalent advantages to those of the devices.

In some embodiments, the device comprises the heat source, wherein after the evaporator, in particular directly after the evaporator of the heat pump, the heat sink return is thermally coupled to the heat source by means of the heat exchanger for absorbing heat. Thereby the heat of the heat source and the heat obtained from cooling the heat sink return by means of the heat pump are provided for the heat sink, in particular for a heat consumer.

In some embodiments, the condenser of the heat pump is thermally coupled to the heat sink return by means of a bypass line. An increased thermal output may thereby be provided for the heat sink.

In some embodiments, the heat sink is part of a district heating network. The thermal output of the district heating network may thereby be increased.

In some embodiments, the heat source is a geothermal source (geothermal heat source) and/or an industrial waste heat source. The temperature of the heat source return of the geothermal source may thereby be further reduced, so that the geothermal source may be cooled better and hence its yield improved. For the industrial waste heat source, advantageously complex and cost-intensive cooling devices for cooling the heat source return may thereby be omitted.

In some embodiments, the heat pump is configured as a high-temperature heat pump. A high-temperature heat pump is a heat pump which allows a heat provision at its condenser above 90 degrees Celsius, in particular above 100 degrees Celsius. Thereby the temperature of the heat sink feed may be further raised. In particular, the temperature of the heat sink feed may be raised to above 90 degrees Celsius. In other words, advantageously the temperature of the heat source may be further utilized.

To achieve said high temperatures, the heat pump may use a working fluid with R1233zd, R1336mzz, butane, cyclopentane and/or with a fluoroketone and/or a mixture of said substances.

In some embodiments, the heat pump has an electrical power of at least 1 Megawatt. Thereby a heat pump is provided which is adequately dimensioned for industrial applications. In particular, said electrical power may be advantageous for a district heating network or a return of provided heat into an industrial process.

FIG. 1 shows the yield of a heat source 6 formed as a geothermal heat source, by means of a heat pump 4 according to the prior art. The yield of the geothermal source 6 is achieved by means of a known device 10 comprising a heat sink 2. The heat pump 4 comprises at least one condenser 41 and an evaporator 42. In connection with the evaporator 42, the geothermal source 6 has a heat source feed 61 and a heat source return 62. Here, the temperature of the heat source return 62 is lower than the temperature of the heat source feed 61 because of the thermal coupling with the evaporator 62 of the heat pump 4. In other words, heat is transmitted from the geothermal source 6 to the evaporator 42 of the heat pump 4. The heat is transmitted to the heat pump 4 by the at least partial evaporation of the working fluid inside the evaporator 42.

In connection with the thermal coupling with the condenser 41 of the heat pump 4, the heat sink 2 has a heat sink feed 21 and a heat sink return 22. The temperature of the heat sink return 22 is lower than the temperature of the heat sink feed 21, or the temperature of the heat sink feed 21 is higher than the temperature of the heat sink return 22. In other words, the temperature of the heat source feed 61 is raised by means of the heat pump 4, and heat is emitted to the heat sink 2 by condensation of the working fluid inside the condenser 41 via the heat sink feed 21.

One disadvantage of the known device 10 is that the temperature of the heat source return 62 cannot be reduced or lowered further. In other words, the yield of the geothermal source 6 is restricted by the heat transmission from the geothermal source 6 to the heat pump 4.

FIG. 2 shows the device 1 according to the first embodiment of the teachings herein. The device 1 comprises a heat pump 2 with a condenser 41 and an evaporator 42. Furthermore, the device 1 comprises a heat source 6 and a heat sink 2, in particular a heat consumer which particularly preferably is part of a district heating network, and a heat exchanger 12.

The heat pump 4 may comprise a compressor and an expansion valve. A working fluid of the heat pump 4 is at least partially condensed by means of the condenser 41, at least partially compressed by means of the compressor, at least partially evaporated by means of the evaporator 42, and at least partially expanded by means of the expansion valve. The working fluid may be R1233zd, R1336mzz, butane, cyclopentane and/or a fluoroketone and/or a mixture of said substances.

In connection with the heat exchanger 12, the heat source 6 has a heat source feed 61 and a heat source return 62. In the exemplary embodiment depicted, the temperature of the heat source feed 61 is for example 95 degrees Celsius. The temperature of the heat source return 62 is for example 35 degrees Celsius.

Furthermore, in connection with the heat exchanger 12 which couples the heat source 6 thermally to the heat sink 2, the heat sink 2 has a heat sink feed 21 and a heat sink return 22. The condenser 41 of the heat pump 4 is thermally coupled to the heat sink feed 21. In other words, the working fluid of the heat pump 4 is at least partially condensed by said thermal coupling and the heat thus released is transmitted to the heat sink feed 21. Here, said thermal coupling takes place directly after the heat exchanger 12. The evaporator 42 of the heat pump 4 is thermally coupled to the heat sink return 22. In other words, heat is extracted from the heat sink return 22 by means of the evaporator 42 and transmitted to the heat sink feed 21 by means of the heat pump 4 and the condenser 41. This allows further cooling of the heat sink return 22, so that via the thermal coupling by means of the heat exchanger 12, the yield of the heat source 6 can be further improved.

For example, the temperature of the heat source feed 61 may be around 95 degrees Celsius [° C.]. Directly after the thermal coupling of the heat source 6 to the heat sink 2 by means of the heat exchanger 12, the heat source return 62 has a temperature of approximately 35 degrees Celsius. Between the heat exchanger 12 and the condenser 41 of the heat pump 4, i.e. directly after the heat exchanger 12 and directly before the condenser 41 of the heat pump 4, the heat sink feed 21 has a temperature of around 90 degrees Celsius. Because of the absorption of heat by means of the heat pump 4, the heat sink feed 21 has a temperature of more than degrees Celsius directly after the thermal coupling to the condenser 41 of the heat pump 4.

The heat sink 2 may comprise a heat consumer and consume or use at least part of the heat which can be supplied to it by means of the heat sink feed 21. Thus, the heat sink return 22 has a lower temperature of approximately 50 degrees Celsius. A temperature of around 50 degrees Celsius then prevails at the evaporator 42 of the heat pump 4. Further heat is extracted from the heat sink return 22 by means of the evaporator 42 of the heat pump 4, so that the temperature of the heat sink return 22 is approximately 30 degrees Celsius after the thermal coupling to the evaporator 42 of the heat pump 4. The heat sink return 22 with a temperature of around 30 degrees Celsius is then conducted to the heat exchanger 12. There the heat sink return 22 again absorbs heat from the heat source 6 and reaches the heat sink feed 21 at a temperature of approximately 90 degrees Celsius. By means of the devices 1 taught herein, the heat content of the yield of the heat source 6 may be improved. As shown, the heat source 6 may comprise a geothermal source.

FIG. 3 shows the device 1 according to a second embodiment of the teachings of the present disclosure. The device 1 from FIG. 3 here substantially comprises the same elements as the device in FIG. 2, so that the statements made in relation to FIG. 2 may be transferred directly to the device 1 depicted in FIG. 3. In addition to the exemplary temperatures named in FIG. 2, exemplary mass flows [kg/s] are shown in FIG. 3, together with the electrical power supplied and thermal output extracted [MW] as examples.

The heat pump 4 receives for example an electrical power of approximately 2 Megawatt. The heat source 6, which in FIG. 3 is formed as a geothermal source, has a thermal output of approximately 15 Megawatt. By increasing the heat from the heat source 6 by means of the heat pump 4 and its integration in the heat sink return 22 and heat sink feed 21, a thermal output of around 17 Megawatt can be provided for the heat sink 2.

In contrast to FIG. 2, the condenser 41 of the heat pump 4 is additionally thermally coupled to the heat sink return 22 by means of a bypass line 23. For this, the bypass line 23 has a pump 8 which pumps at least part of a fluid from the heat sink return 22 to the condenser 41 of the heat pump 4. The thermal coupling of the condenser 41 of the heat pump 4 to the heat sink return 22 depicted allows an increase in the thermal output provided for the heat sink 2. In the embodiment shown in FIG. 3, accordingly essentially the thermal output for the heat sink 2 may be increased. In the embodiment shown in FIG. 2 however, essentially the temperature for the heat sink 2 is increased.

The further elements of the device 1 are arranged and/or integrated in a comparable or identical fashion to the elements of FIG. 2, so the statements made with reference to FIG. 2 may be transferred to the device 1 shown in FIG. 3. Although the teachings herein have been illustrated and described in detail in the form of exemplary embodiments, the scope of the teachings is not restricted by the examples disclosed, and other variations may be derived therefrom by the person skilled in the art without leaving the scope of protection of the disclosure.

Claims

1. A device for increasing the heat yield of a heat source, the device comprising:

a heat sink;

a heat pump with a condenser and an evaporator; and

a heat sink feed and a heat sink return providing a thermal coupling to the heat source by a heat exchanger;

wherein the condenser is thermally coupled to the heat sink feed for emitting heat to the heat sink; and

the evaporator is thermally coupled to the heat sink return for absorbing heat.

2. The device as claimed in claim 1, further comprising the heat source;

wherein downstream of the evaporator of the heat pump, the heat sink return is thermally coupled to the heat source by the heat exchanger for absorbing heat.

3. The device as claimed in claim 1, wherein the condenser of the heat pump is thermally coupled to the heat sink return by a bypass line.

4. The device as claimed in claim 1, wherein the heat sink is part of a district heating network.

5. The device as claimed in claim 1, wherein the heat source comprises a geothermal source and/or an industrial waste heat source.

6. The device as claimed in claim 1, wherein the heat pump comprises a high-temperature heat pump.

7. The device as claimed in claim 6, wherein the heat pump uses a working fluid comprising at least one of: R1233zd, R1336mzz, butane, cyclopentane, a fluoroketone, and a mixture of said substances.

8. The device as claimed in claim 1, wherein the heat pump has an electrical power of at least one Megawatt.

9. A method for increasing the heat yield of a heat source, the method comprising:

transmitting heat from the heat source to a heat sink return using a heat exchanger;

transmitting heat from a condenser of a heat pump to a heat sink feed; and

transmitting heat from the heat sink return to an evaporator of a heat pump;

wherein the heat sink feed and the heat sink return provide a thermal coupling to the heat source by the heat exchanger;

wherein the condenser is thermally coupled to the heat sink feed for emitting heat to the heat sink; and

wherein the evaporator is thermally coupled to the heat sink return for absorbing heat.