WO2019148224A1

WO2019148224A1 - Temperature control device and method for the open-loop and closed-loop control of a temperature control device for a processing device, in particular an injection molding machine

Info

Publication number: WO2019148224A1
Application number: PCT/AT2019/060031
Authority: WO
Inventors: Zdravko GAVRAN
Original assignee: Wittmann Kunststoffgeräte Gmbh
Priority date: 2018-02-01
Filing date: 2019-01-26
Publication date: 2019-08-08
Also published as: AT520890A1; AT520890B1

Abstract

The invention describes a method and a temperature control device (12, 54) for a processing device, in particular an injection molding machine (4), the temperature control device comprising: at least one conveying pump (23) for conveying a medium; a heat exchanger (24, 55, 56); an electric heater (25); a controller (22) for closed-loop and open-loop control; and preferably a housing (20), in which the components are arranged, characterized in that a heating circuit (29) and a cooling circuit (30) are connected to the same heat exchanger (24, 55, 56), but only one circuit is activated at a time, the heat exchanger (24, 55, 56) and/or the electric heater (25) and a process medium (32) flowing through being arranged in a pressure vessel (31). The invention further relates to a method and a temperature control device, in which the controller (22) is designed in such a way that the amount of heat and the amount of cold that can be supplied or removed by means of at least one heat exchanger (24, 55, 56) are determined and/or clogging or calcification of at least one heat exchanger is determined.

Description

Temperature control device and method for controlling and regulating a temperature control for a processing device, in particular a Spitzgießmaschine

The invention relates to a temperature control device and a method for controlling and regulating a temperature control device for a processing device, in particular an injection molding machine, as described in the preambles of claims 1, 2, 10 and 11.

There are already tempering for a processing device, in particular a

Injection molding machine, known to provide at least one feed pump for conveying a

Process medium, a heat exchanger in the form of a spiral, a tube bundle, or a plate heat exchanger, a control electronics for controlling and preferably, and a housing in which the components are arranged comprises. As a rule, in such a temperature control unit, an electric heater is used to supply the process medium (water or thermal oil) and thus also the consumers connected thereto, for example. an injection molding tool to heat to a desired operating temperature.

But if a hot spring, in particular a waste heat from a combined heat and power plant or superheated steam from a steam generator, is available, it is possible to use this external source to heat the process medium and the consumers connected to it. As a result, electrical energy and thus high costs can be saved. For this, however, it is necessary to use an additional second heat exchanger, which must be located in the consumer circuit. Via this additional second heat exchanger, the heat is released from the hot medium available from the external source to the process medium. Thus, it is known from the prior art in such temperature control that a heat exchanger for cooling and the second heat exchanger connected to the external source is used for heating the process medium.

A disadvantage of the temperature control unit described that an additional heat exchanger for the external heat source is needed.

The object of the invention is therefore to provide a temperature control and a method of the type mentioned above, on the one hand to avoid the disadvantages described above and on the other hand to provide easy control and regulation of the temperature and a high operator comfort.

The object is achieved by the invention.

The temperature control device according to the invention is characterized in that a heating circuit and a cooling circuit are connected to one and the same heat exchanger, but only one circuit is activated, wherein in a pressure vessel, the heat exchanger and / or the electric heater and a flowing process medium is arranged.

The advantage here is that the production costs can be significantly reduced by the use of only a single heat exchanger in the temperature. This also results in reduced investment costs for the user when purchasing a new temperature control unit. The use of only one heat exchanger is made possible by the control alternately, ie, as needed, either the heating circuit or the cooling circuit is passed through the heat exchanger. Thus, the circulating process medium, which is conveyed through the pressure vessel and to which the consumers are connected, either heated or cooled. To high

Operating temperatures or to achieve a rapid heating of the process medium, the controller can also operate the integrated electric heater. Thus, a very compact temperature control, especially for use in plastics technology, can be created.

Furthermore, the object of the invention is also achieved by a temperature control, in which the control is designed such that a determination of the amount of heat and cold, the over at least one heat exchanger can be supplied or removed, and / or blockage or calcification of at least one heat exchanger takes place.

The advantage here is that without additional external devices, as is the case in the prior art, for example, for the determination of the amount of heat, the Auslangen is found. Since all required functions can now be determined and analyzed inside the device, the commissioning of the temperature control unit in a work cell is simplified, and the mobility between different work cells is increased, since this only via the corresponding connection cable and the

Supply lines for the process medium must be connected. Further

Wiring for external auxiliary devices are thereby avoided.

According to a particular feature of the invention valves with subsequent check valves for cold and hot medium are arranged in the flow and in the return of the heat exchanger. As a result, the two circuits can be connected separately to the heat exchanger by the controller in a simple manner. Due to the arrangement of a check valve ensures that no liquid can penetrate into the hot or cold circuit.

But there are also the features of advantage in which a bypass line is provided between the flow and the return of the hot medium, in which a temperature sensor is preferably arranged. This ensures that during operation of the refrigeration cycle via the heat exchanger, the temperature in the heating circuit is measured via the bypass line, so that the determined temperature value for the control is available at all times.

An advantage is an embodiment in which a temperature sensor for detecting the temperature of the process medium, preferably in the region of the process medium output, is arranged. This ensures that the controller has at all times the temperature of the process medium for the control available and thus can decide based on the desired preset operating temperature, whether the heating circuit and / or the electric heater or the refrigeration cycle must be activated. According to an advantageous embodiment, the controller for comparing or regulating the temperature of the hot medium of the heat exchanger with the temperature of the

Process medium formed, and determines according to Regelalgorythmen when, how long and whether at all with the hot medium or with the electric heater, the process medium is controlled to the predetermined setpoint. This achieves that by comparison between current process medium temperature, the desired process medium operating temperature and the temperature of the hot

Medium, the control based on defined control algorithms decides when and how long is heated with the hot medium, and if and for how long and when should be heated with the electric heater. Thus, it can be ensured in an advantageous manner that the consumers are supplied with sufficient heat energy.

Also advantageous is a training in the flow and in the return of the

Heat exchanger, ie at the entrance and exit of the heat exchanger, one each

Temperature sensor is arranged and only in one of the two lines, ie in the flow or in the return, a volume flow measurement is integrated. This makes it possible that the quantity of heat can be determined by the control device due to the differential temperature between flow and return and the measured volume flow. Thus, no additional external devices, as is known from the prior art, are necessary for the determination of the amount of heat.

According to an advantageous feature of the invention is in the flow and in the return of

Heat exchanger arranged in each case a pressure sensor and integrated in one of the two lines, ie in the flow or return, a volume flow measurement. As a result, the controller can, due to the knowledge of the pressure difference as a function of the

Volume flow determine a pressure loss or load curve for the heat exchanger. Thus, the reliability is significantly increased, as early as a

Blockage is detected by the controller itself or can be reacted early on a calcification of the heat exchanger. It is also an object of the invention to provide a method for controlling and regulating a temperature control device for a processing device, in particular an injection molding machine.

The inventive method is characterized in that the heating circuit and the cooling circuit via a common, arranged in a pressure vessel, heat exchanger is performed, wherein by alternately activating valves either a hot medium of the heating circuit or a cold medium of the cooling circuit through the or the heat exchanger is guided, wherein the process medium for heating or cooling of a connected consumer is conveyed through the pressure vessel.

The advantage here is that when using an external energy source for heating the process medium, such as a waste heat of a

Cogeneration plant or superheated steam from a steam generator, exactly the amount of energy consumed can be determined.

This can be determined by the temperature control, in particular the controller, how much energy saved by using a hot source for heating the process medium, or how much energy was spent on the cooling of the process medium.

Furthermore, the object of the invention is also achieved by a method in which is determined or determined by the control of the temperature control unit, a heat and cold amount and / or calcification of at least one heat exchanger.

It is advantageous here that the determination of the amount of heat and cold can be carried out without external devices. This makes it possible that both during operation and after operation, the amount of heat and cold can be retrieved. Also, it is possible that early detection of calcification of one or more

Heat exchanger from the temperature control unit, in particular the controller, a warning signal can be issued, so that appropriate countermeasures can be initiated.

But there are also the measures of advantage, in which the temperature of the hot

Medium via a temperature sensor in a bypass line between flow and Return of the medium associated with this heat exchanger is detected. As a result, the temperature in the heating circuit is monitored during operation with the refrigeration cycle and can by the controller for further control or control operations

be used.

But also advantageous are the measures in which by the control device by comparing the temperature in the bypass line with a detected temperature of the process medium according to stored control algorithms of the heating circuit or the

Cooling circuit is applied to the heat exchanger or to the heat exchangers and / or is determined by the controller, whether an arranged in the pressure vessel electric heater is activated. This ensures that always enough heat energy for

Heating a connected consumer, such as an injection mold, is available.

According to a feature of the invention, the temperature at the flow and at the return of the one or more heat exchangers as well as the volume flow occurring is measured to determine or determine the amount of heat and cold. This ensures that the amount of heat can be determined without additional external devices from the temperature control itself. Thus, when using an external energy source for heating the process medium, such as waste heat from a cogeneration unit or superheated steam from a steam generator, exactly the amount of energy consumed can be determined. This can be determined by the temperature control, in particular the controller, how much energy by using a hot source for heating the

Saved process medium, or how much energy was spent on the cooling of the process medium.

But there are also the measures of advantage, in which the pressure at the flow and at the return of the heat exchanger or the occurring volume flow is measured to determine a blockage or calcification. This ensures that the reliability of the temperature control unit and thus also the consumers connected to it is substantially increased because of the occurrence of errors, in particular Blockages, which are detected very early by the controller and appropriate action can be taken.

Finally, the measures are advantageous in which the controller determines and deposits a pressure loss or load characteristic curve on the basis of the knowledge of the pressure difference as a function of the volume flow. It is thereby achieved that during a slow calcification or clogging of the heat exchanger, the controller recognizes this and can display, for example, the current state of the heat exchanger or the percentage blockage on the display of the temperature. Thus, before the occurrence of a critical point at which the consumers can no longer be adequately supplied, the temperature control unit can be replaced or decalcified.

The invention will be described with reference to several in the drawings

Embodiments explained in more detail.

Show it:

Fig. 1 is an overview of a plastic processing industrial plant, in a simplified, schematic representation;

Fig. 2 shows an inventive tempering with open side wall, in

simplified, schematic representation;

Fig. S shows an embodiment of a structure for a heat exchanger of a

tempering device according to the invention, in a simplified, schematic representation;

Fig. 4 shows another embodiment of a structure for the heat exchanger of

tempering device according to the invention, in a simplified, schematic representation; Fig. 5 shows another embodiment of a structure for the heat exchanger of

tempering device according to the invention, in a simplified, schematic representation; Fig. 6 shows an embodiment in which all variants in a structure for the

Heat exchanger of the temperature control device according to the invention, in a simplified, schematic representation;

Fig. 7 shows a symbolic structure with external heat sources for the temperature, in a simplified, schematic representation. By way of introduction, it should be noted that in the various embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals and component names. Also, the location selected in the description, such as top, bottom, side, etc. are based on the described figure and are mutatis mutandis transferred to the new location in a change in position. Also, individual features or feature combinations from the illustrated and described embodiments may be self-contained

represent innovative solutions.

In Fig. 1 is an industrial plant 1, in particular a working cell 2 for

Injection molding applications shown in which the individual components / devices for producing one or more products / semi-products or injection molded parts 3 are connected together in the work cell 2. As a processing machine is preferably a

Injection molding machine 4, which uses a robot 5 or automatic handling machine for

Removing the manufactured injection molded part 3 is assigned. The injection-molded part 3 is removed from an opening injection mold 7 by a removal device 6, in particular a gripper equipped with gripper tongs or suction nozzles, and deposited on a device, in particular a conveyor belt 8. In order to be able to produce an injection-molded part 3, plastic granules 9 are fed to the processing machine 4 via a granulate conveyor 10 and possibly via a metering device 11. About one

Temperature control unit 12 and / or cooling device, the injection mold 7 can be maintained by supplying a tempering to operating temperature or heated or cooled accordingly, so that optimal processing of the plastic granules 9, which must be plasticized for injection into the injection mold 7, is made possible. In addition, the system has a monitoring system 13, in particular a camera system, in order to be able to carry out automatic quality control of the product or injection-molded part 3 produced. In order that the individual devices can be set or programmed, these have corresponding controls (not shown), whereby corresponding settings or programming are made via displays 14 or a robot control 15 arranged on the devices, or the parameters or program codes are displayed. For the sake of completeness, it is further mentioned that all devices are connected to corresponding lines, in particular voltage supply, network lines, fluid supply lines, material lines, etc., which have not been shown in the illustration shown for the sake of clarity.

In FIGS. 2 to 5, the temperature control device 12 according to the invention is now shown and described in more detail.

The temperature control unit 12 has a housing 20, which is preferably equipped with wheels 21 for easy positioning in the work cell 2. For the adjustment and display of these, the temperature control unit in the front region of the display 14, which is provided for example by a touchpad and / or setting controls, buttons, etc. The display 14 and other electronic elements or sensors of the device are connected to a controller 22, the lines are not shown for clarity.

Furthermore, the temperature control unit 12 comprises at least one feed pump 23 for conveying a medium, a heat exchanger 24, an electric heater 25, which are connected via lines 26 with corresponding terminals to the medium to be heated or cooling components, such as the injection mold 7, to promote. Preferably, the temperature control unit 12 has heating water connections 26 and cooling water connections 27, to which the external components for heating and cooling are connected.

It is essential in the temperature control unit 12 according to the invention that it has only a single heat exchanger 24 for a heating circuit 29 and a cooling circuit 30. The heat exchanger 24 is arranged or integrated in a pressure vessel 31. In addition, the electric heater 25 is also arranged in the pressure vessel 31. The pressure vessel 31 is flowed through by a process medium 32. The process medium 32 can thus be heated or cooled via the heat exchanger 24 and / or additionally heated with the electric heater 25. The process medium 32 is that medium which is supplied to the connected components via the connections, in particular the heating water connections 27 or cooling water connections 28. In this case, the process medium 32 can be used for example by water or a heat transfer oil. In general, the electric heater 25 is used in the temperature control unit 12 to the process medium 32 and thus also the consumer, such as the

Injection mold or the injection mold 7 to heat to a desired operating temperature. But if a hot source is e.g. Waste heat from a combined heat and power plant, superheated steam from a steam generator, etc., available, so there is the possibility to heat the process medium 32 and the consumer with this. For this purpose, such an external heat source, as shown schematically in Fig. 7, via corresponding connections 33, in particular a flow and return, are connected. For this it is necessary that the heat exchanger 24 is located in the consumer circuit, so that the heat from the hot available medium is delivered to the process medium 32 via this.

In FIGS. 3 to 6, a schematic representation of the flow chart or sequence with the heat exchanger 24 in different variants of the temperature control unit 12 is shown.

As can now be seen in the variant of FIG. 3, the heat exchanger 24 is located in the pressure vessel 31 together with the electric heater 25. The process medium 32 flows through the pressure vessel 31, i. the process medium 32 flows over one

Process medium inlet 34 into the pressure vessel 31 and flows around it in the

Heat exchanger 24 and the electric heater 25, whereupon the heated or cooled process medium via the process medium outlet 35 the pressure vessel 31 leaves again and can be promoted to a consumer.

In the flow 36 and the return 37 of the heat exchanger 24 are valves 38, 39 with subsequent check valves 40,41 for cold and hot medium, in particular heating circuit 29 and the cooling circuit 30. The valves 38, 39 can be opened by magnetic coils, stepper motors or compressed air and closed to pass through the respective medium through the heat exchanger 24. The check valves 40, 41 thereby prevent the undesirable flow of the hot medium into the line of the cold medium and vice versa. Between a flow 42 and a return 43 of the hot medium, ie of the heating circuit 29, a bypass line 44 is provided, in which a temperature sensor 45 is located. As a result, the temperature of the hot medium is permanently detected and passed on to the controller 22 of the temperature control unit 12, that flows continuously via the bypass line 44, a hot medium, regardless of whether the heat exchanger 24 is operated with the heating circuit 29 or the cooling circuit BO.

The controller 22 is thus constantly the temperature of the heating circuit 29 is available, so that by comparing current process temperature of the

desired set process medium operating temperature and the temperature of the hot medium in the heating circuit 29, the controller 22 based on defined

Control algorithms decide when and how long with the hot medium of the

Heating circuit 29 is heated, and whether and for how long and when to be heated with the electric heater 25.

According to the variant in Fig. 4, located in the flow 36 and in the return 37 of the

Heat exchanger 24 each have a temperature sensor 46, and only in one of the two lines (flow 42 or return 43) a flow measurement 47. If a cold or hot medium flows through the heat exchanger 24, the temperature on the temperature sensor 46 at the input and output of Heat exchanger 24 and the volume flow occurring thereby measured via the volume flow measurement 47 and sent to the controller 22. If heat is now transferred to the process medium 32 via the heat exchanger 24 in the pressure vessel 31 -heating cycle 29 is active-or the process medium 32 is withdrawn -cooling circuit 30 is active-a differential medium temperature results between the heat exchanger and the outlet Flow 42 and return 43. With this differential temperature and the measured volume flow, the heat energy can be determined by the controller 22 and displayed for example on the display 14. This heat energy provides information about how much energy was saved by using a hot source for heating the process medium 32, or how much energy was expended for cooling the process medium 32.

Since clogging of the heat exchanger 24 can occur in such temperature control devices 12, the temperature control device 12 according to the invention has a correspondingly Blockage protection or a Verstopfungswarnung equipped, as described in Fig. 5. The constipation is caused by the deposition of lime and

Dirt particles or mud, sand, etc. With a blockage is a

Cooling / heating of the process medium 32 is no longer possible and thus no longer guarantees the desired operating temperature. This can be up to one

Production stop on the consumer / the production machine, such as the injection molding machine 4 lead.

In the flow 36 and the return 37 of the heat exchanger 24 are pressure sensors 48, and only in one of the two lines (supply or return 36, 37) a

Volume flow measurement 47. If a cold or hot medium now flows through the heat exchanger 24, the pressure at the inlet and at the outlet of the heat exchanger 24 as well as the occurring volume flow is measured. The construction and construction of the heat exchanger 24 results in a pressure loss when medium flows through it. This pressure loss increases proportionally or exponentially with the volume flow. The pressure loss results in a pressure difference between

Heat exchanger input and output, ie flow 36 and return 37. The controller can with the knowledge of the pressure difference as a function of the flow

Determine pressure loss or consumer characteristic for the heat exchanger 24. This is preferably stored in the controller 22 of the temperature control unit 12.

Now sets the heat exchanger 24 with time with lime or dirt, it can be determined by measuring the differential pressure with the associated volume flow, an operating point and compared with the stored in the controller 22 load curve. As a result, the current state of the heat exchanger 24 or the percentage blockage is displayed on the display 14 of the temperature control unit 12. Thus, even before the critical point is reached, the temperature control unit 12 is removed from production and the heat exchanger 24 is cleaned or decalcified.

For this purpose, it is also possible that stored setpoint values for the operating point are set and stored. If the operating point reaches the desired value, the controller 22 can send out a warning, in particular a warning signal. In Fig. 6, a combination of all previously described variants of FIGS. 3 to 5 is shown in a single temperature control unit 12 or are these integrated in a single device, wherein the temperature control unit 12 is still only a single heat exchanger 24 for the heating circuit 29th and the cooling circuit 30. It is possible that the

different functions can be activated simultaneously.

Fig. 7 shows a schematic representation of an application with supply of external heat sources, such as waste heat from a block power plant 49 and / or superheated steam of a steam generator 50, etc. The heat is thereby via lines 51, 52 to the connected households and / or factories 53, as shown schematically with dashed lines supplied. At these external heat sources are shown in the

Embodiment, the temperature control device 12 according to the invention with only one

Heat exchanger 24 and a further temperature control unit 54 with two or more

Heat exchangers 55, 56 connected, which are connected via lines 57, 58 to a consumer, in particular the injection molding machine 4 or injection mold 7, respectively. Here, the second temperature control unit 54 is equipped with two or more heat exchangers 55, 56, which is also equipped with the corresponding sensors, in particular the temperature sensors, the volume flow measurement and the pressure sensors, so that even in this temperature control unit 54 of the controller, the heat and cold , and / or the

Calcification or constipation, as previously described in detail, can be determined or determined. Of course, it is possible that only one of them, so only the amount of heat or only the amount of cold, can be determined by the controller 22 or can be displayed.

For the sake of order, it is pointed out that the invention is not limited to the illustrated embodiment variants, but may also include further embodiments.

Claims

claims:

1. temperature control unit (12, 54) for a processing device, in particular a

Injection molding machine (4), comprising at least one delivery pump (23) for conveying a medium, a heat exchanger (24, 55, 56), an electric heater (25), a controller (22) for regulating and controlling, and preferably a housing (20) in which the components are arranged, characterized

characterized in that a heating circuit (29) and a cooling circuit (30) are connected to one and the same heat exchanger (24,55,56), but only one circuit is activated, wherein in a pressure vessel (31) of the heat exchanger (24,55 , 56) and / or the electric heater (25) and a flow-through process medium (32) is arranged.

2. temperature control unit (12, 54) for a processing device, in particular a

characterized in that the controller (22) is designed such that a determination of the amount of heat and cold, the at least one

Heat exchanger can be added or removed, and / or blockage or calcification of at least one heat exchanger (24,55,56) takes place.

3. temperature control unit (12,54) according to claim 1 or 2, characterized in that for determining or determining the heat and cold quantity, and / or for determining the constipation or calcification, the temperature control unit (12,54) for carrying out the method is formed according to one or more of claims 10 to 16.

4. tempering device (12,54) according to claim 1 to 3, characterized in that in the flow (36) and in the return (37) of the heat exchanger (24,55,56) valves (38,39) with subsequent check valves (40,41) are arranged for cold and warm medium.

5. temperature control unit (12,54) according to any one of the preceding claims, characterized in that between the flow (36) and the return (37) of the hot medium, a bypass line (44) is provided, in which preferably a temperature sensor (45 ) is arranged.

6. tempering device (12,54) according to any one of the preceding claims, characterized in that a temperature sensor for detecting the temperature of the process medium (32), preferably in the region of the process medium output (35), is arranged.

7. temperature control unit (12,54) according to any one of the preceding claims, characterized in that the controller (22) for comparing or regulating the

Temperature of the hot medium of the heat exchanger (24,55,56) with the temperature of the process medium (32) is formed, and determines according to Regelalgorythmen when, how long and whether at all with the hot medium or with the electric heater (25) Process medium (32) is controlled to the predetermined setpoint.

8. tempering device (12,54) according to any one of the preceding claims, characterized in that in the flow (36) and in the return (37) of the heat exchanger

(24.55.56), so at the entrance and exit of the heat exchanger (24,55,56), in each case a temperature sensor (46) is arranged and only in one of the two lines, ie in the flow (36) or in the return (37), a volume flow measurement (47) is integrated.

9. tempering device (12,54) according to any one of the preceding claims, characterized in that in the flow (36) and in the return (37) of the heat exchanger

(24.55.56) in each case a pressure sensor (48) is arranged, and only in one of two lines, so in the flow (36) or return (37), a flow measurement (47) is integrated.

10. A method for controlling and regulating a temperature control unit (12,54) for a

Processing device, in particular an injection molding machine (4), in which via a feed pump (23) a process medium (32) to connected consumers, such as an injection mold or injection mold (7), promoted to heat the consumer to a desired operating temperature or to be cooled, wherein the control of the individual components via a controller (22), characterized in that the heating circuit (29) and the

Cooling circuit (30) via preferably a common, in one

Pressure vessel (31) arranged heat exchanger (24,55,56) is guided, wherein by alternately activating valves (38,39) either a hot medium of the heating circuit (29) or a cold medium of the cooling circuit (30) by the or Heat exchanger (24,55,56) is guided, wherein the

Process medium (32) for heating or cooling a connected

Consumers through the pressure vessel (31) is conveyed through.

11. A method for controlling and regulating a temperature control unit (12,54) for a

Processing device, in particular an injection molding machine (4), in which via a feed pump (23) a process medium (32) to connected consumers, such as an injection mold or injection mold (7), promoted to heat the consumer to a desired operating temperature or , wherein the control of the individual components via a controller (22), characterized in that by the controller (22) of the

Temperature control unit (12,54) is determined or determined a heat and cold amount and / or calcification of at least one heat exchanger (24,55,56).

12. The method according to claim 10 or 11, characterized in that the

Temperature of the hot medium via a temperature sensor (45) in a bypass line (44) between the flow (42) and return (43) of, this medium associated heat exchanger (24,55,56) is detected.

13. The method according to any one of the preceding claims 10 to 12, characterized

characterized in that by the controller (22) by comparing the temperature in the bypass line (44) with a detected temperature of the process medium (32) according to stored control algorithms of the heating circuit (29) or the cooling circuit (30) on the heat exchanger (24, 55,56) or to the

Heat exchangers (24,55,56) is applied and / or the controller (22) determines whether an in the pressure vessel (31) arranged electrical heater (25) is activated.

14. The method according to any one of the preceding claims 10 to 13, characterized

characterized in that for determining or determining the heat and

Refrigerant the temperature at the flow (36) and at the return (37) of the heat exchanger or (24,55,56) and the volume flow occurring is measured.

15. The method according to any one of the preceding claims 10 to 14, characterized

in that the pressure at the forerunner (36) and at the return (37) of the heat exchanger or heat exchangers (24, 55, 56) as well as the volume flow occurring in the process are measured to determine clogging or calcification.

16. The method according to any one of the preceding claims 10 to 15, characterized

characterized in that from the controller (22) due to the knowledge of the pressure difference as a function of the volume flow, a pressure loss or load curve is determined and deposited.