System and method for heat recovery in a beverage production plant

Abstract

This document describes a system and a method for heat recovery in a beverage production plant, and in particular a beer production plant. The system comprises a heat pump with a primary circuit for supplying waste heat from the plant via a first fluid and a secondary circuit for dissipating heat from the process to at least one heat consumer in the plant via a second fluid. Because the primary circuit includes at least one heater, in particular a heat exchanger, for additionally heating the first fluid, and because the supply of heating energy to the heater, in particular the heat exchanger, can be metered mechanically to adjust the primary-side flow temperature of the heat pump, efficient operation of the heat pump is possible even with fluctuating and comparatively low quantities or temperatures of waste heat.

Description

[0001] The invention relates to a system and method for heat recovery in a plant for beverage production, in particular for beer production.

[0002] As is well known, thermal energy is required for production processes in beer production plants (breweries), each of which is used to heat associated heat consumers. Typical heat consumers include mash tuns, wort kettles, bottle washing machines, flash pasteurization systems, or CIP systems (for cleaning containers or pipes, for example, using "cleaning in place"). Lauter wort heaters or hot water preparation can also be such heat consumers.

[0003] In the dairy industry, milk heating or pasteurization (e.g., ultra-high temperature treatment) of intermediate and finished products are important. In the production of lemonade, for example, intermediate products (such as sugar syrup) and / or the final product are also pasteurized.

[0004] Heating is usually done indirectly via heat exchanger surfaces with steam (100 to 180 °C), high-pressure hot water (110 to 180 °C) or low-temperature water (80 to 110 °C).

[0005] In the following, high-pressure hot water is also abbreviated as “HDHW” and low-temperature water as “NTW”.

[0006] Beer production requires a relatively high thermal energy requirement. Accordingly, the associated production facilities also contain heat sources from which thermal energy can be recovered and reused. Examples include steam condensers and wort coolers. Thermal energy can be recovered from the steam in the steam condenser, and the thermal energy stored in the wort in the wort cooler. Recovered thermal energy can be used, for example, in a subsequent process and / or subsequent brew, for example, for heating the lautering wort and / or mash heating.

[0007] In addition, breweries or other beverage production facilities usually have heat sources, such as a refrigeration system, compressed air system, or wastewater, from which heat energy can also be recovered, but at a relatively low temperature level, for example, 15 to 75°C. These temperature levels are usually too low to heat heat consumers, for example, based on the temperatures required for individual process steps in breweries. For example, hot water preparation is not possible with this type of waste heat because of the hot water temperature of the so-called sparging water required for lautering, for example, 76 to 82°C. Another example is the heating of lauter wort from usually 76°C to 92°C.

[0008] It is known in principle from the state of the art to heat water to a higher temperature level using heat pumps in order to use it as a heating medium for heat consumers.

[0009] To achieve a high COP (Coefficient of Performance) of the heat pump, the fluid flows should be supplied with a temperature spread appropriate to the respective application and with temperatures and flow rates that are as constant as possible. In general, the efficiency and thus also the COP of a heat pump increases with the primary inlet temperature. Accordingly, the COP / efficiency increases the smaller the temperature spread between the fluid to be cooled supplied on the primary side (i.e., the colder side of the heat pump) and the working temperature of the fluid to be heated on the secondary side (i.e., the warmer side of the heat pump). It is generally desirable to maximize the COP value.

[0010] However, since breweries usually require heating medium temperatures (in other words the temperature of the heating medium) well above 100°C, it is usually not efficient or possible to achieve these temperatures from waste heat of, for example, less than 40°C, even when using heat pumps.

[0011] From DE 102011 055 147 B4, it is known to combine a heat pump with a stratified storage tank for energy recovery in a brewery. Both the primary (low-temperature) fluid flow and the secondary (high-temperature) fluid flow are buffered in the stratified storage tank before being fed to the heat pump. This allows, in principle, the temperatures of the fluid flows fed to the heat pump to be adjusted. For this purpose, the stratified storage tank is positioned upstream of the heat pump in the process direction. This allows the fluid to be discharged via outlets of the stratified storage tank at staggered height levels at different temperatures and fed to the heat pump. The inlet temperature is adjusted by mixing and is therefore always lower than the maximum temperature of the waste heat recovered from the heat sources used.For example, thermal energy from 40°C to 75°C can be recovered from a refrigeration system and stored in a stratified storage tank. During storage, a mixed temperature is then set for the heat pump, which can never correspond to the maximum temperature in this storage tank, as otherwise, lower-temperature layers would build up, be unused, and thus imbalance the system.

[0012] The disadvantages are therefore an unsatisfactory efficiency / COP of the heat pump, depending on the temperature levels of the waste heat used, and the inadequate usability of heat sources with relatively low temperature levels. As mentioned, DE 10 2011 055 147 B4 describes the use of a stratified storage tank, in which a heat transfer medium from different layers of the storage tank and thus also different temperatures is mixed together in order to provide a heat pump with a constant temperature level. However, this has the disadvantage that it is only ever possible to achieve a temperature below the highest temperature of the recovery from a heat source. Furthermore, it can result that more heat, i.e. thermal energy, is available from a source with a lower temperature than can be raised to a level suitable for a heat pump by mixing.This means that only a portion of the available thermal energy can be fed back into a heat supply system using a heat pump, or a heat pump is not used and the thermal energy is lost.

[0013] There is a corresponding need for remedial action.

[0014] This object is achieved by a system and a method according to the independent claims. Preferred embodiments are specified, inter alia, in the dependent claims.

[0015] Accordingly, the system serves for heat recovery in a plant for beverage production, in particular for beer production, and for this purpose comprises a heat pump with a primary circuit for supplying waste heat to the plant via a first fluid and with a secondary circuit for dissipating working heat to at least one heat consumer of the plant via a second fluid. According to the invention, the primary circuit comprises at least one heater, in particular a heat exchanger, for additionally heating the first fluid, wherein the supply of heating energy to the heater, in particular a heat exchanger, can be mechanically metered in order to adjust the primary-side flow temperature of the heat pump.

[0016] Accordingly, in the process, waste heat is supplied to the system via the first fluid, and working heat from the heat pump is discharged to at least one heat consumer of the system via the second fluid in an associated secondary circuit. The first fluid is additionally heated in the primary circuit by at least one heater, in particular a heat exchanger, and the supply of heating energy to the heater, in particular a heat exchanger, is mechanically metered, thereby adjusting the primary flow temperature of the heat pump.

[0017] This allows the heat pump to operate with improved efficiency (COP). Furthermore, waste heat at a comparatively low temperature can also be utilized. The primary flow temperature can also be set and / or maintained relatively precisely and flexibly, for example, under different operating conditions of the associated production plant.

[0018] Described process steps and functions of the system can therefore correspond to each other in a mutually interchangeable and / or complementary manner.

[0019] The first fluid fed to the heat pump on the primary side, i.e. on the colder side, is preferably water, which is conducted in particular in a closed circuit (pipe system). However, other heat transfer fluids can also be used, e.g. thermal oil. Water, in particular that of drinking water quality, is also advantageously suitable for the production of beer (e.g. as mash water, sparging water), for pushing media out of pipes and / or for cleaning the system technology (in this case using an open pipe system, i.e. the water can leave the system and is then replaced with fresh water). The open pipe system can be designed with just a single storage tank or with several storage tanks, the several storage tanks are then connected to one another.The single storage unit can have several temperature levels and the several storage units can each have a maximum of two temperature levels, but preferably only one temperature level each.

[0020] The primary circuit of the heat pump can also be referred to as its low-temperature circuit, and the secondary circuit as its high-temperature circuit.

[0021] The heater, specifically the heat exchanger, is external to the heat pump and therefore not part of the heat pump or heat pump system. The heat exchanger can be a plate, tube, or spiral heat exchanger, for example. However, other vessels with bottom and / or frame heating surfaces are also suitable in principle. An electrically operated heating device is also suitable as a heater.

[0022] The heater, especially the heat exchanger, offers the following advantages: • In contrast to the current state of the art, the primary flow temperature can be adjusted not only by mixing, but also, or instead, independently of the temperatures prevailing in an associated fluid storage tank. Depending on the wiring of the primary circuit, the fluid storage tank can be designed as a stratified storage tank or as a buffer storage tank. • A primary-side stratified storage tank and the resulting mixing of different temperatures (of the heat sources) are not necessary for the operation of the heat pump. • Heat sources with relatively low temperature levels of, for example, less than 25°C can be utilized by increasing the temperature as described using heaters, in particular heat exchangers.

[0023] The at least one heater, in particular heat exchanger, can in principle be arranged at various locations in the primary circuit of the described recovery system, for example: • in the return flow of several or individual heat sources (i.e. in front of a fluid storage tank, if present); and / or • in the inlet to the heat pump (i.e. after any existing fluid storage).

[0024] If the heater, in particular heat exchanger, is arranged in the return line of at least one heat source, i.e. in particular in front of a fluid storage device, the following advantages result, for example: • The fluid storage tank does not have to be designed as a stratified storage tank, since the temperature level required on the primary side of the heat pump can be set by the heater, in particular the heat exchanger. The fluid storage tank can therefore be a buffer tank with only an upper and lower connection, which respectively function as inlet and outlet, and thus works with two temperature levels, namely an upper and a lower one. This is then a fluid storage tank without mixing. The prevailing upper temperature level is then essentially the primary side flow temperature of the first fluid (on the colder side of the heat pump) set for the heat pump. The prevailing lower temperature level is then essentially the primary side return temperature of the first fluid, which can be fed back to at least one heat source for the recuperation of thermal waste heat.

[0025] If a separate heater, particularly a heat exchanger, is connected downstream of each heat source (not shown), large temperature differences due to discontinuous heat sources or temperature fluctuations between individual heat sources can be better compensated. The respective outlet temperature of the first fluid from such separate heaters, particularly heat exchangers, is preferably identical and then essentially corresponds to the set primary flow temperature of the heat pump. This results in the following advantages, for example: • Any fluid storage tank that may be present can be relatively small, as it only needs to have a volume buffer function (decoupling the volume flows of the heat source(s) and the heat pump). Alternatively, the primary circuit of the heat pump can be designed without a fluid storage tank (buffer tank or stratified storage tank). The volume and mass flows of the heat pump and the at least one heat source are then coordinated with one another. Without a fluid storage tank, the heat pump is preferably designed for the base load of the at least one heat source and / or for the one heat consumer connected to the heat pump on the secondary side (since partial load operation of heat pumps is usually not practical or economical depending on their design). With a fluid storage tank, waste heat from peak loads can also be captured and buffered, thus maximising the use of available waste heat.

[0026] If the heater, in particular the heat exchanger, is located in the inlet to the heat pump, i.e. in particular from its perspective behind (downstream) a fluid storage tank, the following advantages arise, for example: • In the case of a heater, in particular a heat exchanger, located downstream of the fluid storage tank and upstream of the heat pump, the fluid storage tank can be charged from the heat sources by means of one or more charging lances, so that the first fluid from one or more heat sources is stored in layers in the fluid storage tank depending on the respective temperature and density. Depending on the embodiment of the invention, the fluid storage tank can be a stratified storage tank or a buffer storage tank. Since a constant temperature is generally not established in the upper part of the fluid storage tank, mixing of the first fluid in a stratified storage tank would always be necessary to set the primary-side flow temperature of the heat pump without a heater, in particular a heat exchanger, with the achievable flow temperatures then always being below the highest available waste heat temperature.The (downstream) heater, especially a heat exchanger, offers the advantage that the primary flow temperature of the heat pump can be flexibly adjusted and can be higher than with mixing. An additional advantage is the reduction of radiation losses from the fluid storage, since the first fluid can be stored or layered at an overall lower temperature than downstream of a heater, especially a heat exchanger.

[0027] The heat exchanger(s) can be supplied with heating media from primary energy sources, for example in the form of steam, high-pressure hot water or low-temperature water from a boiler house, which is supplied with primary energy sources such as oil, (bio)gas, wood or others, or from secondary energy sources, for example condensate from a process application or from other recuperative processes, such as solar thermal energy or a combined heat and power plant.

[0028] A primary or secondary energy source for the heater can also be an electrical power source (to provide electrical energy).

[0029] In principle, the described heat pump could also be used as an energy source for the heat exchanger by means of the second fluid heated on the secondary side (on the warmer side).

[0030] In principle, any heating medium with suitable temperature and availability can be used.

[0031] If a second fluid is evaporated by means of the heat pump, this is understood to mean steam which has a temperature of 100 to 180°C and a pressure of preferably up to 10 bar or possibly even more (for example after leaving a compressor assigned to the heat pump).

[0032] A heat pump, for example in connection with steam generation, is understood to mean the entire unit required, including peripherals such as compressors, etc.

[0033] Regardless of the type of secondary fluid heated on the secondary side, for example steam, high-pressure hot water (HPHW), or low-pressure hot water (NTW), the heat pump can also be a multi-stage system and / or a series-connected heat pump, i.e. any heat pump system suitable for the described application.

[0034] By definition, a stratified storage tank is a storage tank with at least three vertically staggered connections for the fluid inlet and outlet. A buffer storage tank, on the other hand, is a storage tank with a maximum of two vertically staggered connections for the fluid inlet and outlet. The buffer storage tank can be designed for hydraulic decoupling with only a single connection for the fluid inlet and outlet, in which case it can additionally have a maximum of two additional connections, one of which serves only as a fluid inlet and the other as a fluid outlet.

[0035] Preferred embodiments of the invention are illustrated in the drawings. Fig. 1 a first embodiment; Fig. 2 a second embodiment; and Fig. 3 a third embodiment.

[0036] As the Fig. 1, the system 1 for heat recovery in a plant 100 for beverage production, and in particular for beer production, comprises a heat pump 2 with a primary circuit 3 for supplying waste heat 4 from the plant 100 by means of a first fluid 5 and with a secondary circuit 6 for dissipating working heat 7 to at least one heat consumer (not shown) of the plant 100 by means of a second fluid 8. The primary circuit 3 comprises at least one heater, in particular heat exchanger 9 for additionally heating the first fluid 5 and here also a fluid reservoir 10 for storing the first fluid 5.

[0037] The supply of heating energy 11 to the heater, in particular heat exchanger 9, can be mechanically metered in order to adjust the primary-side flow temperature 12 of the first fluid 5 or the heat pump 2, for example by heating the first fluid 5 from a supply temperature 13 prevailing in the heater, in particular heat exchanger 9, after being discharged from the fluid reservoir 10, to the primary-side flow temperature 12.

[0038] The dosage of heating energy 11 for the heater, in particular heat exchanger 9, can be regulated as needed, for example, by means of a (particularly electronic) control / regulation unit 14, for example by automatically adjusting the inflow of a heating medium (not separately designated in the figures) transporting the heating energy 11 from an energy source 15 to the heat exchanger 9 depending on the supply temperature 13 and / or the volume flow of the first fluid 5 upstream of the heat exchanger 9. The heating medium can be, for example, water or electricity. For this purpose, the actual primary-side flow temperature 12 in the process direction downstream of the heater, in particular heat exchanger 9, is preferably continuously monitored. Suitable control methods and associated devices are known in principle and therefore not explained in detail.

[0039] The waste heat 4 can be recovered from several heat sources 16 - 18. The first fluid 5 heated with the waste heat 4 (thermal energy) from the heat sources 16 - 18 is temporarily stored in the fluid storage 10. This can be temperature-dependent if the fluid storage 10 is, as in the case of the Fig. 1 is a stratified storage tank 20, then preferably by means of horizontal charging lances 21. In principle, however, so-called stratified charging lances 22 in a vertical design would also be suitable ( Fig. 3).

[0040] Solar thermal energy with a relatively low temperature level can, on the one hand, function as a heat source 16 - 18 and provide correspondingly tempered waste heat 4. On the other hand, solar thermal energy with a relatively high temperature level can function as an energy source 15 and provide heating energy 11 for the heater, in particular heat exchanger 9.

[0041] From there, the first fluid 5 from at least one layer of the stratified storage tank 20 is passed through the heater, in particular heat exchanger 9, and is heated from the supply temperature 13 to a predetermined primary-side flow temperature 12 of the heat pump 2. The first fluid 5 heated with the waste heat 4 (thermal energy) from the heat sources 16-18 can additionally or alternatively be fed directly (i.e., without intermediate storage in the fluid storage tank 10) to the heater, in particular heat exchanger 9.

[0042] The first fluid 5, which is adjusted to the primary-side flow temperature 12 in the heater, in particular heat exchanger 9, can now be fed directly to the heat pump 2 and / or stored and buffered in the fluid storage 10 / stratified storage 20 by means of the uppermost horizontal charging lance 21. For example, this would be practical with a primary-side flow temperature 12 of 30 - 40°C. The first fluid 5, which has been cooled on the primary side in the heat pump 2 (on its colder side), is fed back into the fluid storage 10 / stratified storage 20 by means of the lowermost horizontal charging lance 21 and / or used again to recover waste heat from the heat sources 16 - 18, for example, with a primary-side return temperature 19 of at least 5°C.

[0043] The heat exchanger 9 can in principle be fed from a primary or secondary energy source 15. A heat source with a temperature level below 100°C but which supplies the required thermal energy for the heat exchanger 9 in terms of volume and temperature is preferred. A combined heat and power plant is an example. Combined heat and power plants usually have a waste heat temperature level below 100°C or a temperature that is below the heating temperatures required in a brewery. In a brewery, temperatures of at least 115°C are usually necessary, for example, to achieve efficient wort boiling. However, any other suitable energy source 15 can also be used to adjust the flow temperature 12 of the first fluid 5 in the heat exchanger 9.

[0044] Alternatively, an electrically powered heater (not specifically shown) may be present instead of the heat exchanger 9.

[0045] The heat sources 16 - 18 are preferably those whose waste heat 4 cannot be used in production processes, for example due to a relatively low temperature level. A first heat source 16 can be, for example, a refrigeration system, a second heat source can be, for example, wastewater 17, and a third heat source 18 can be, for example, a compressed air system / compressor. However, other heat sources are also possible, for example, solar thermal systems, brewing processes such as wort cooling and / or pan vapor condensation, geothermal systems, combined heat and power plants, district heating networks, and others. In warm countries, the temperature of fresh water, which is used in a brewery for various purposes (as product water, for cleaning, etc.), can also be higher than, for example, 20°C. This water can also be used as a heat source by cooling it and thereby recovering waste heat 4 (thermal energy).

[0046] For example, waste heat 4 can be recovered from a refrigeration system at a temperature level of at least 30°C, and in particular at a constant temperature. Wastewater typically ranges from the used cold water temperature up to a temperature of 80°C. A practical example is an average recovery temperature (of the waste heat 4) of at least 20°C. The volume flows of individual waste heat recovery units are combined, resulting in a mixing temperature of the first fluid 5, which is adjusted via the heater, in particular heat exchanger 9, to a desired primary-side flow temperature 12 of, for example, at least 30°C.

[0047] The Fig. Figure 2 shows a second embodiment of system 1, which differs from the previously described embodiment essentially in that the heater, in particular heat exchanger 9, is connected upstream of the fluid reservoir 10, which here is designed as a buffer reservoir 30 with only two horizontal (an upper and a lower) charging lances 21. The primary circuit 3 has a correspondingly different piping layout from the first embodiment.

[0048] It is also indicated that the first fluid 5 could optionally bypass the heater, in particular heat exchanger 9, via a bypass 23 if the supply temperature 13 of the first fluid 5 immediately upstream of the heater, in particular heat exchanger 9, already corresponds to the desired primary-side flow temperature 12 of the heat pump 2. Alternatively, the supply of heating energy 11 to the heater, in particular heat exchanger 9, could be omitted in such a case, and the first fluid 5 could flow through the inactive heater, in particular heat exchanger 9 (this applies generally, i.e., to all embodiments).

[0049] In a variant (not shown), individual heat sources 16-18 could be assigned separate heaters, in particular heat exchangers 9, which then uniformly heat the first fluid 5 to the primary-side flow temperature 12. Also, only one of the illustrated heat sources 16-18 or a different number may be present or used as described (this applies generally, i.e., to all embodiments).

[0050] Downstream of the heater, in particular heat exchanger 9, the first fluid 5 can also be led directly to the heat pump 2 and / or temporarily stored in the fluid storage 10 / buffer storage 30.

[0051] For selective and / or partial forwarding of the first fluid 5, known line branches, actuators, and pumps can be used in principle, which are therefore neither described in detail nor indicated in the figures. This applies generally, i.e., to all embodiments.

[0052] In contrast to the stratified storage tank 20, the buffer tank 30 has only two temperature levels and preferably only two connections with the function of an inlet and outlet, see the directional arrows indicated as an example.

[0053] The primary-side return temperature 19 of the heat pump 2 is preferably at most 20°C, more preferably at most 10°C, and ideally at most 5°C.

[0054] The primary-side flow temperature 12 of the heat pump 2 is preferably at least 30°C, more preferably at least 40°C, and ideally at least 50°C. This also applies to all embodiments.

[0055] The heat pump 2 used can, for example, be of the water / water or water / steam type. However, other heat pump systems may also be suitable. If the heat pump 2 is for the secondary side generation of steam, condensate is fed into the secondary side flow. The second fluid 8 then consists, by definition, of condensate in the flow and steam in the return. Such condensate preferably originates from a heat transfer process within a brewery in which steam is used to heat a product. When using steam, it should be emphasized that converting an existing system (e.g. a wort kettle) to a different heating medium such as high-pressure hot water or low-pressure hot water is then not necessary.

[0056] A storage tank (not shown), preferably a buffer tank, but possibly also a stratified storage tank, can be connected downstream of the secondary side of the heat pump 2, i.e. its warmer side. In a steam application, this is then a steam storage tank. Preferably, the heated second fluid 8 (in particular in the form of steam), but without buffering, is used directly in a process heat application, for example for heating in a CIP process, for lautering wort heating, for wort boiling or the like. This could be any application in a brewery for which the heated second fluid 8 can be used, for example, also for wort boiling if the temperature of the second fluid 8 is sufficient.

[0057] A storage tank (not shown), preferably a buffer tank, but possibly also a stratified storage tank, can be connected upstream of the secondary side of heat pump 2, i.e., its warmer side. In a steam application, this is then a condensate storage tank. When using high-pressure hot water or low-temperature water, the upstream and downstream storage tanks can be a single storage tank.

[0058] The embodiment according to Fig. 3 differs from the previously described embodiments essentially in that the heater, in particular heat exchanger 9 in the primary circuit 3, is connected downstream of a fluid storage tank 10, which is a buffer tank 30 with a vertical stratified charging lance 22. This results in the following functionality of the fluid storage tank 10.

[0059] The fluid reservoir 10 / buffer reservoir 30 is charged with the first fluid 5, which has previously been heated by waste heat 4 from one or more heat sources 16-18, by means of the vertical stratified charging lance 22. This first fluid 5 is stored in the fluid reservoir 10 at a corresponding height depending on its inlet temperature and density.

[0060] The first fluid 5 returning from the primary side of the heat pump 2 is also stored in the lowest area of ​​the fluid storage 10 / buffer storage 30. Instead and / or partially, this fluid can be returned to the heat sources 16-18 for further waste heat recovery.

[0061] By definition, the Fig. The fluid reservoir 10 shown in Figure 3 is a buffer reservoir 30, since the first fluid 5 is only stored via the vertical stratified loading lance 22 and there are no more than two connections with the common function of inlet and outlet. It would also be a buffer reservoir 30 if there were several connections, of which only one has the common function of inlet and outlet.

[0062] In the example of Fig. 3, the first fluid 5 heated by the waste heat 4 is stored via the stratified charging lance 22 depending on the prevailing temperature level and is only discharged via the upper connection. The lower connection serves as the inlet and outlet. Thus, the fluid storage 10 of the Fig. 3 is by definition not a stratified storage tank 20, but a buffer storage tank 30.

[0063] If, however, the fluid storage 10 has more than two connections with the function of storage and removal, it is a stratified storage 20, see the Fig. 1. When we talk about storage and retrieval or storage and retrieval, we mean a connection through which both processes take place.

[0064] Compared to a fluid storage 10 with a previously set temperature, storage in layers has the advantage that lower radiation losses occur.

[0065] Due to different temperatures of the respectively stored first fluid 5 and mostly discontinuous availability of the waste heat 4, the temperature of the first fluid 5 in the uppermost region of the fluid storage 10 can vary.

[0066] According to Fig.3, the first fluid 5 is taken from the uppermost region of the fluid reservoir 10 / buffer reservoir 30 and adjusted to a preferably temporally constant primary-side flow temperature 12 by means of the heater, in particular heat exchanger 9, with a preferably constant flow of the first fluid 5. The (respective maximum) temperature prevailing in the uppermost region of the fluid reservoir 10 / buffer reservoir 30 depends on the waste heat 4 from the heat sources 16-18 and can possibly be influenced during the heat transfer there to the first fluid 5.

[0067] By removing the first fluid 5 from the uppermost storage area, it is fed to the heater, in particular heat exchanger 9, at the highest temperature prevailing in the fluid storage 10 / buffer storage 30, i.e., the supply temperature 13. This can be lower than the maximum temperature reached by the first fluid 5 at a heat source 16-18 by transferring waste heat 4. The waste heat 4 can generally be fed into the system 1 at a relatively low temperature level, for example, below 25°C, and heated via the heater, in particular heat exchanger 9, to the desired primary-side flow temperature 12, thus making it usable.

[0068] The primary-side flow temperature 12 can nevertheless be achieved at least partially by mixing the first fluid 5 before, in, or at the fluid reservoir 10 / buffer reservoir 30. If this alone is sufficient, the heater, in particular the heat exchanger 9, is inactive. Otherwise, it supplies the required heating energy 11 to the first fluid 5 in order to adjust the primary-side flow temperature 12 of the heat pump 2 and, in particular, to maintain it constant.

[0069] The primary flow temperature 12 could also be varied as required and the heating energy 11 required for this at the heater, in particular heat exchanger 9, could be dosed / regulated accordingly.

[0070] In general, this results in the advantage that the primary flow temperature 12 of the heat pump 2 can be flexibly adjusted with the heater, in particular the heat exchanger 9, and is largely independent of the source temperatures of the waste heat 4. This allows thermal energy to be integrated into the heat pump process that was previously unusable or very difficult to utilize due to insufficient temperatures. This applies, for example, to waste heat 4 from wastewater or fresh water with a temperature of, for example, 20°C or less.

[0071] Depending on the type of heat pump 2, the second fluid 8 can be the following medium, which is supplied to the heat pump: • Condensate in the flow, condensate and steam in the return; • High pressure hot water in the flow and return lines (heated there); or • Low-temperature water in the flow and return (heated there)

[0072] Steam, heated high-pressure hot water and heated low-temperature water then act as working heat 7.

[0073] If heat consumers in the brewery are supplied with steam as a heating medium, then steam as a second fluid 8 can be advantageous for minimizing investment costs, since the heat consumers are then still supplied with steam as a heating medium. At the very least, downtimes for conversion and the construction of a new heating network can be avoided. Since heat pumps should operate as continuously and evenly as possible, heat pump 2 is designed so that it primarily covers the base load of steam generation, and a steam boiler only has to cover peak loads. Furthermore, heat pump 2 can generally improve, i.e., minimize, the CO2 footprint of a beverage production plant or a brewery.

[0074] This advantageously enables the use of waste heat sources 4 across a comparatively broad temperature spectrum. For example, a refrigeration system will typically have a waste heat temperature of at least 30°C up to 75 to 80°C in its circuit to one or more condensers. To recover the waste heat 4, the volume flow of the absorbing first fluid 5 can be constant, causing its temperature to fluctuate, or this temperature can be kept constant at 30°C, for example, causing the volume flow to fluctuate.

[0075] The heater, in particular heat exchanger 9, makes it possible, in particular in cooperation with the fluid storage 10, to compensate for such fluctuations and to provide the heat pump 2 in the primary circuit 3 with the first fluid 5 with a suitable primary-side flow temperature 12 and, if necessary, to keep this constant, with the volume flow as constant as possible.

[0076] During operation of system 1, the primary flow temperature 12 is preferably continuously monitored, and deviations from this are compensated for by mechanically dosing the heating energy 11 for the heater, in particular the heat exchanger 9. This is possible in principle with all described embodiments.

[0077] For example, a permissible fluctuation range of the primary-side flow temperature 12 is a deviation from a setpoint of the primary-side flow temperature 12 of + / - 15°C, in particular + / - 10°C, in particular + / - 5°C. The setpoint of the primary-side flow temperature 12 is, for example, at least 30°C, in particular at least 40°C. This also applies to all described embodiments, whose features of the primary circuit 3 are therefore, in principle, combinable and / or interchangeable.

[0078] When we talk about a stratified storage tank, the term stratified storage tank should be understood as a synonym.

[0079] The term beverage production and beer production also includes the bottling of beverages and beer. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102011 055 147 B4 [0011, 0012]

Claims

[1] System (1) for heat recovery in a plant (100) for beverage production and in particular for beer production, comprising a heat pump (2) with a primary circuit (3) for supplying waste heat (4) of the plant (100) by means of a first fluid (5) and with a secondary circuit (6) for discharging working heat (7) to at least one heat consumer of the plant (100) by means of a second fluid (8), characterized by that the primary circuit (3) comprises at least one heater, in particular heat exchanger (9) for additionally heating the first fluid (5), wherein the supply of heating energy (11) to the heater, in particular heat exchanger (9), can be mechanically metered in order to adjust the primary-side flow temperature (12) of the heat pump (2). [2] System according to claim 1, wherein the heating energy (11) to the heater, in particular heat exchanger (9) is regulated such that the primary-side flow temperature (12) deviates from a setpoint of at least 30°C, in particular at least 40°C, by no more than + / - 15°C, in particular no more than + / - 10°C, in particular no more than + / - 5°C. [3] System according to claim 1 or 2, wherein the primary circuit (3) upstream of the heat pump (2) comprises a fluid reservoir (10) for the first fluid (5), which is connected upstream or downstream of the heater, in particular heat exchanger (9). [4] System according to claim 3, wherein the primary circuit (3) is designed such that the first fluid (5) can be conducted therein selectively and / or proportionally from the heater, in particular heat exchanger (9) to the heat pump (2), from the heater, in particular heat exchanger (9) to the fluid reservoir (10) and / or from the fluid reservoir (10) to the heat pump (2). [5] System according to claim 4, wherein the fluid reservoir (10) is a stratified reservoir (20) and the primary circuit (3) is further designed such that the first fluid (5) can be stored and discharged selectively and / or proportionally at different height levels of the stratified reservoir (20). [6] System according to one of claims 3 to 5, wherein the primary circuit (3) is designed such that the first fluid (5) from the return of the heat pump (2) can be directed selectively and / or proportionally to the fluid reservoir (10) or back to at least one heat source (4) of the system (100). [7] Plant (100) for beverage production, in particular for beer production, comprising the system (1) according to at least one of the preceding claims and at least one heat source (16 - 18) supplying the primary circuit (3) with the waste heat (4), in particular in the form of: a refrigeration system; waste water; a compressed air compressor; a solar thermal system; a brewing process unit, in particular a wort cooler and / or a pan vapor condenser; and / or a combined heat and power plant. [8] Method for heat recovery in a plant (100) for beverage production, in particular for beer production, wherein waste heat (4) of the plant (100) is supplied to a heat pump (2) in an associated primary circuit (3) by means of a first fluid (5) and working heat (7) is discharged from the heat pump (2) in an associated secondary circuit (6) to at least one heat consumer of the plant (100) by means of a second fluid (8), characterized bythat the first fluid (5) in the primary circuit (3) is additionally heated by at least one heater, in particular heat exchanger (9), wherein the supply of heating energy (11) to the heater, in particular heat exchanger (9), is mechanically metered and the primary-side flow temperature (12) of the heat pump (2) is thereby adjusted. [9] Method according to claim 8, wherein the heating energy (11) to the heater, in particular heat exchanger (9) is controlled in such a way that the primary-side flow temperature (12) deviates from a setpoint of at least 30°C, in particular at least 40°C, by no more than + / - 15°C, in particular no more than + / - 10°C, in particular no more than + / - 5°C. [10] Method according to claim 8 or 9, wherein the first fluid (5) in the primary circuit (3) is selectively and / or partially conducted from the heater, in particular heat exchanger (9) to the heat pump (2), from the heater, in particular heat exchanger (9) to a fluid reservoir (10) and / or from the fluid reservoir (10) to the heat pump (2). [11] Method according to claim 10, wherein the first fluid (5) is stored and discharged upstream of the heater, in particular heat exchanger (9) for stratified storage, selectively and / or proportionally at different height levels of the fluid reservoir (10). [12] Method according to claim 8 or 9, wherein the first fluid (5) downstream of the heater, in particular heat exchanger (9), is selectively and / or partially stored in an upper region of a fluid reservoir (10) designed in particular as a buffer reservoir (30), is discharged from there and / or is passed directly to the heat pump (2). [13] Method according to one of claims 10 to 12, wherein the first fluid (5) after flowing through the heat pump (2) is selectively and / or partially directed to the fluid reservoir (10) or back to at least one heat source (4) of the system (100). [14] Method according to at least one of claims 8 to 13, wherein the second fluid (8) is high-pressure hot water, in particular that with a secondary-side return temperature of 110 to 180 °C, or low-temperature water, in particular that with a secondary-side return temperature of 80 to 110 °C, or condensate from which steam is generated in the heat pump (2), in particular that with a secondary-side return temperature of 100 to 180 °C. [15] Method according to at least one of claims 8 to 14, wherein the first fluid (5) is water and this absorbs the waste heat (4) by means of heat exchange from at least one heat source (16 - 18).

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