METHOD FOR CONTROLLING THE HEAT TRANSFER FLOW OF A CIRCUIT COMPOSITE SYSTEM AND DEVICE THEREFOR

Description

[0001] The invention relates to a method for controlling the heat transfer medium volume flow in a closed-loop system according to the preamble of claim 1, as well as to a closed-loop system for carrying out a method for controlling the heat transfer medium volume flow according to the preamble of claim 3 and to a use of a closed-loop system according to claim 5.

[0002] Heat recovery processes in conjunction with closed-loop heat recovery systems are widely known and frequently used. This was reported in a technical article by Dr. Christoph Kaup, "Hybrid High-Performance Heat Recovery Based on the Closed-Loop Heat Recovery System," published in the 2004 / 05 Technical Journal, pages 4 to 11. Further publications on this topic are documented in "Heat and Cold Recovery in Ventilation Systems," 5th edition, 2001, ISBN 3-8041-2233-7.

[0003] Both publications explain that energy is extracted from the exhaust air of a ventilation unit. This recovered energy is then transferred back to the supply air supplied to the ventilation unit.

[0004] The heat extraction from the exhaust air is regulated by pumping less or more heat transfer medium (intermediate medium) through the exhaust air heat exchanger and through the supply air heat exchanger.

[0005] The required or desired volume flow of the heat transfer medium (intermediate medium) is calculated using the heat flow capacities for the air volume flow and the volume flow of the intermediate medium (heat transfer medium) according to the relationship m L xc pL = m Z xc pZ (L = air side / Z = intermediate medium). However, this does not allow the required volume flow of the heat transfer medium to be inadequately controlled. Firstly, the specific heat capacities c pL for air and c pZ for the intermediate medium (heat transfer medium) are not constant. Secondly, the mass flows m L and m Z can also vary. In addition, to determine the mass flows for the air flows passing through, suitable measuring devices for the corresponding volume flows are required, which, however, are only available with a fairly wide tolerance range. In addition, to calculate the heat capacities using the mass flows of the air, temperature and humidity measuring devices assigned to the air volume flows are required.This serves to determine the density of the air volume flows and increases the complexity of the ventilation unit considerably.

[0006] DE 20 2013 105 854 U1 discloses a heat recovery system for ventilation systems, which comprises a heat recovery system for a ventilation and air-conditioning system. A first heat exchanger is provided in an exhaust air stream and a second heat exchanger is provided in a supply air stream. These heat exchangers are coupled to a heat transfer medium by a pipe system connecting them to form a closed-loop system. A pump circulates the heat transfer medium. Some measuring sensors are provided with a control unit for controlling the pump based on a comparison of recorded measured values ​​as actual values ​​with setpoints. Measuring sensors are used to determine an air temperature and a heat transfer medium temperature. For pump control, only recorded temperature measured values ​​are compared as actual values ​​with a setpoint. DE 20 2013 105 854 U1 discloses a method according to the preamble of claim 1 and a closed-loop system according to the preamble of claim 3.

[0007] A heat recovery device equipped with the previously described state-of-the-art features is therefore quite complex. In this case, the actual achievable heat recovery even deviates downwards from the calculated heat recovery. This is due to the previously mentioned system-related measurement inaccuracies and the inevitable tolerances that arise during the value determination.

[0008] According to the solution proposed in the prior art, the amount of heat energy actually recovered is therefore less than the maximum amount of heat energy that can be recovered.

[0009] This applies in particular if Unequal air mass flows are conveyed between supply and extract air, a different water content of the extract air is present, and also when different extract air temperatures and outside temperatures exist. Furthermore, the thermodynamic properties of the heat transfer medium change with the different temperatures, as the internal heat transfer coefficient changes during partial load flow due to the lower velocity of the heat transfer medium and / or the air density changes with the weather conditions and the local altitude of the ventilation system.

[0010] Furthermore, DE 10 2012 105 255 A1 discloses a device for controlling a defined flow rate without a flow meter. This device comprises a programmable control device in conjunction with a frequency converter for the centrifugal pump in a heat pump's hydraulic system on the condenser side. The control device determines the required flow rate based on the heat pump's requested heating output. In a closed-loop system, the air volume flow of a ventilation unit is transmitted to a control device via an analog or digital signal to determine the operating parameters of a centrifugal pump. This device has the same disadvantages of the other prior art described above.The object of the present invention is therefore to achieve highly effective heat and cold recovery with little effort, even with a wide variety of outside and exhaust air temperatures, different humidities of the supply and exhaust air and different air volume flows of the supply air and the exhaust air, by controlling the heat transfer medium volume flow in a way that is adapted to the performance.

[0011] To solve the problem, a method for controlling a heat transfer medium volume flow in a closed-loop system according to the features of claim 1 is proposed.

[0012] A method for controlling a heat transfer medium flow rate is implemented in a closed-loop system with at least one supply air heat exchanger arranged in a supply air flow rate and at least one exhaust air heat exchanger arranged in an exhaust air flow rate. The supply air heat exchanger(s) and the exhaust air heat exchanger(s) are coupled by means of heat transfer lines such that a heat transfer medium can be conveyed successively through all supply air heat exchangers arranged in the supply air flow rate and then through all exhaust air heat exchangers arranged in the exhaust air flow rate by means of at least one circulation pump.

[0013] According to the invention, the closed-loop system is operated on the basis of temperature measurements of the heat transfer medium volume flow before entering the exhaust air heat exchanger(s) and after leaving the exhaust air heat exchanger(s), as well as a volume flow measurement of the heat transfer medium volume flow carried out in parallel thereto, wherein by changing the speed of the circulating pump, the heat transfer medium volume flow is regulated in such a way that the maximum possible power transmission by means of the heat transfer medium is determined by means of the measured heat transfer medium volume flow and the temperature measurements, and the speed of the circulating pump and thus the heat transfer medium volume flow are regulated in such a way that the maximum possible power transmission by means of the heat transfer medium is achieved.

[0014] Furthermore, the heat transfer medium volume flow in the closed-loop system is regulated on the basis of temperature measurements of the heat transfer medium before the exhaust air volume flow enters the exhaust air heat exchanger(s) and after it leaves the exhaust air heat exchanger(s), as well as a volume flow measurement of the heat transfer medium volume flow carried out in parallel, in such a way that when an increasing power transfer by means of the heat transfer medium is detected, the heat transfer medium volume flow is changed by means of the circulating pump after a previously decreasing power transfer by means of the heat transfer medium, contrary to a previously made volume flow change, or is changed by a smaller amount compared to a previously made volume flow change after a previously increasing power transfer by means of the heat transfer medium.

[0015] Furthermore, a variant of the closed-loop system not covered by the claims and therefore not covered by the invention can be operated on the basis of temperature measurements of the exhaust air volume flow before it enters the exhaust air heat exchanger(s) and after it leaves the exhaust air heat exchanger(s) as well as the supply air volume flow before it enters the supply air heat exchanger(s) with a maximum possible degree of temperature change in the exhaust air volume flow.

[0016] Furthermore, by means of an embodiment not covered by the claims, the closed-loop system can be operated on the basis of temperature measurements of the supply air volume flow before entering the supply air heat exchanger(s) and after leaving the supply air heat exchanger(s) as well as of the exhaust air volume flow into the exhaust air heat exchanger(s) with a maximum possible degree of temperature change in the supply air volume flow.

[0017] In another embodiment not covered by the claims, the heat transfer medium volume flow in the closed-loop system is regulated on the basis of temperature measurement values ​​of the exhaust air volume flow before entering the exhaust air heat exchanger(s) and after leaving the exhaust air heat exchanger(s) or of temperature measurement values ​​of the supply air volume flow before entering the supply air heat exchanger(s) and after leaving the supply air heat exchanger(s) in such a way that when a reduction in the degree of temperature change in the respective air volume flow compared to a maximum possible degree of temperature change is detected, the heat transfer medium volume flow is changed by means of the circulating pump contrary to a previously made volume flow change.

[0018] A closed-loop system according to the invention comprises a temperature sensor in a heat transfer line before the heat transfer medium enters the exhaust air heat exchanger(s) and a temperature sensor in a heat transfer line after the heat transfer medium exits the exhaust air heat exchanger(s). Furthermore, a volume flow measuring device is assigned to the circulation pump. A control device is provided in conjunction with the temperature sensors, the volume flow measuring device, and the circulation pump.

[0019] The connection is designed in such a way that, based on the measured values, an increasing or decreasing power transmission of the heat transfer medium is regulated by changing the heat transfer medium volume flow.

[0020] Another device not covered by the claims comprises a temperature sensor in a first air volume flow, one before the inlet and one after the outlet of the volume flow from the associated heat exchanger(s). Furthermore, a temperature sensor is arranged after the outlet from the heat exchanger(s) of the other air volume flow. A control device is provided in conjunction with the temperature sensors and the circulation pump, such that, based on the measured values ​​determined, a decreasing degree of temperature change of the first air volume flow is compensated for by changing the heat transfer medium volume flow.

[0021] In an embodiment not covered by the claims, a temperature sensor for detecting an exhaust air temperature before the inlet and a temperature sensor for detecting an exhaust air temperature after the exhaust air volume flow exits the exhaust air heat exchanger(s) are provided in the exhaust air volume flow. Another temperature sensor for detecting an outside air temperature is arranged after the outlet from the supply air heat exchanger(s) of the supply air volume flow. The temperature sensors are connected to the control device.

[0022] In a variant not part of the invention, a temperature sensor for detecting an outside air temperature is arranged in the supply air volume flow before the inlet, and a temperature sensor for detecting a supply air temperature is arranged after the supply air volume flow exits the supply air heat exchanger(s). Another temperature sensor for detecting an exhaust air temperature is arranged after the outlet from the exhaust air heat exchanger(s) of the exhaust air volume flow. The temperature sensors are connected to the control device.

[0023] In a further development, an arrangement of a closed-loop system according to the invention in connection with several ventilation units is provided.

[0024] In a further development, the use of a closed-loop system according to the invention for the dehumidification of an air volume flow is also provided.

[0025] Preferably, a closed-loop system is constructed from at least one piping system, a circulation pump, a frequency converter, a flow meter with a continuous output signal, at least two temperature sensors, and a measuring device with a programmable logic controller and a continuous controller. The two temperature sensors measure the inlet temperature of the heat transfer medium into the exhaust air heat exchanger and the outlet temperature from the exhaust air heat exchanger and transmit the data to a programmable logic controller (PLC) for processing in the control process. In the programmable logic controller (PLC), the power is calculated according to the relationship Q = V x xcx Δt / 3.6 (V = volume flow / = density / c = specific heat capacity / Δt = temperature difference before and after the heat exchanger). Using the continuous controller, the speed of the circulation pump is then reduced or increased via the frequency converter, so that the highest possible heat recovery performance is always achieved.

[0026] If the continuous controller reduces the heat transfer fluid flow rate and the power also decreases, the controller will increase the heat transfer fluid flow rate again. If the controller increases the heat transfer fluid flow rate and the power decreases, the controller will decrease the heat transfer fluid flow rate again.

[0027] The density and the heat capacity c as constants in the formula of the previously described relationship. On the other hand, it is also possible to use known relationships in formulas for the heat transfer medium used and the measured temperatures to determine the actual density and the actual heat capacity c and use these values ​​to calculate the power. If the density and the heat capacity c of the heat transfer medium, the value of the maximum achievable extraction capacity that can be extracted from the exhaust air is obtained. This value can then be displayed on a display device.

[0028] According to another method not covered by the claims, the optimal heat transfer volume flow can be determined by maximizing the temperature change rate instead of calculating the power transfer. This occurs independently of the air volume flows of the supply air and the exhaust air, as well as the humidity in the exhaust air. For this purpose, the temperature of the exhaust air, the exhaust air, and the outside air is measured and transmitted to a PLC (programmable logic controller). With the help of the PLC, the greatest temperature change rate is determined using a formula for a temperature change rate Φ = (tABL - tFOL) / (tABL - tAUS). Using a continuous controller, the speed of the circulating pump is then reduced or increased via the frequency converter so that the greatest temperature change rate is always achieved.If the continuous controller reduces the heat transfer medium flow rate and the temperature rate of change also decreases, the continuous controller increases the heat transfer medium flow rate again. If the continuous controller increases the heat transfer medium flow rate and the temperature rate of change subsequently decreases, the continuous controller decreases the heat transfer medium flow rate again.

[0029] The advantages that can be achieved with the invention include the effects described below: a) The mass flow of the supply air and extract air no longer needs to be measured to determine the heat transfer medium volume flow. b) The extract air humidity no longer needs to be measured to determine the heat transfer medium volume flow. c) Inaccuracies in the measurement and calculation of heat capacities are eliminated. d) Inaccuracies in the measurement and calculation of the supply and extract air volume flows due to system-related tolerances are eliminated. e) Multiple ventilation units can be connected to a single runaround system. f) Even when heating and cooling are coupled, the optimal heat transfer medium volume flow is always determined. g) The overall measurement effort is lower. h) Heat recovery from the extract air is maximized. i) Cold recovery from the extract air is maximized. j) Changes in the internal heat transfer coefficient with reduced flow velocity of the heat transfer medium are automatically taken into account.

[0030] An embodiment of the invention as well as further examples not falling within the scope of the invention are illustrated below by way of example with reference to the drawings. Figure 1 shows an embodiment of a circuit combination system according to the invention for regulating a heat transfer medium volume flow via a maximum possible heat transfer power, Figure 2 shows an arrangement not covered by the invention for regulating a heat transfer medium volume flow via a maximum possible temperature change, Figure 3 shows a further embodiment of the arrangement according to Figure 1 , Figure 4 shows a further embodiment of the arrangement according to Figure 2, Figure 5 shows an arrangement not covered by the invention for controlling a heat transfer medium volume flow via a maximum possible degree of temperature change, Figure 6 shows a flow diagram of a control process according to the invention based on temperature measurements of the heat transfer medium, and Figure 7 shows a flow diagram of a control process not covered by the claims based on temperature measurements of the exhaust air volume flow and the supply air volume flow.

[0031] In Figure 1An arrangement of a closed-loop system according to the invention is shown. The closed-loop system has two supply air heat exchangers ZU1 and ZU2 in the supply air volume flow ZV between an outside air supply and a supply air exhaust. These are connected in series by means of a heat transfer line 1 against the flow direction of the supply air volume flow ZV. A filter F1 is connected upstream of the supply air heat exchangers ZU1 and ZU2 in the supply air volume flow ZV, and a droplet eliminator T1 and a supply air fan V1 are connected downstream.

[0032] The closed-loop system comprises two exhaust air heat exchangers AB1 and AB2 in the exhaust air volume flow AV, located between an exhaust air inlet and an exhaust air outlet. These are connected in series via a heat transfer line 2, counter to the flow direction of the exhaust air volume flow AV. A filter F2 and an exhaust air fan V1 are installed upstream of the exhaust air heat exchangers AB1 and AB2 in the exhaust air volume flow AV, and a droplet eliminator T2 is installed downstream.

[0033] The supply air heat exchanger ZU1 and the exhaust air heat exchanger AB2 are connected to each other by means of a heat transfer line 3 in a flow direction towards the exhaust air heat exchanger AB2.

[0034] The supply air heat exchanger ZU2 and the exhaust air heat exchanger AB1 are connected to each other by means of a heat transfer line 4 in a flow direction towards the supply air heat exchanger ZU2.

[0035] The heat transfer lines 3, 4 are coupled by a line 5 for exhaust air extraction in the flow direction to the heat transfer line 4. The line 5 is coupled into the heat transfer line 4 by a motor-controlled KVS valve 6.

[0036] The heat transfer lines 3, 4 are further coupled to the heat transfer line 3 by a line 7 for power control and anti-icing protection in the flow direction. The line 7 is coupled into the heat transfer line 3 by a motor-controlled valve 8.

[0037] A circulation pump 9 is also arranged in the heat transfer line 4, with a flow direction from the exhaust air heat exchanger AB1 to the supply air heat exchanger ZU2. The circulation pump 9 conveys the heat transfer medium through the supply air heat exchangers ZU1, ZU2, the valve 8, the exhaust air heat exchangers AB2, AB1, and the KVS valve 6 back to the circulation pump 9. In the heat transfer line 4, a shut-off valve 10 is arranged upstream of the circulation pump 9 and a shut-off valve 11 is arranged downstream.

[0038] These technical connections also essentially apply to Figures 2 to 4.

[0039] After Figure 1According to the invention, a temperature sensor t2 is arranged in the heat transfer medium line 3 before the heat transfer medium enters the exhaust air heat exchanger AB2, and a temperature sensor t1 is arranged in the heat transfer medium line 4 after the heat transfer medium exits the exhaust air heat exchanger AB1. Furthermore, a volume flow measuring device (flow meter) 12 for the conveyed heat transfer medium is provided in the heat transfer medium line 4. The volume flow measuring device (flow meter) 12 is arranged here between the KVS valve 6 and the circulation pump 9.

[0040] Furthermore, a control device R is shown in connection with the circulation pump 9 and the volume flow measuring device (flow meter) 12, as well as the temperature sensors t1 and t2.

[0041] The temperature sensors t2 and t1 as well as the volume flow measuring device (flow meter) 12 are connected to a continuous controller (not shown here) by means of the control device R. The continuous controller changes the heat transfer medium volume flow via the circulation pump 9, which can be either increased or decreased. The temperature difference between the temperature sensors t1 and t2 is determined by means of the continuous controller, and the transferred power is calculated.

[0042] If the circulation pump 9 delivers too little heat transfer fluid, the transferred power decreases because too little heat transfer fluid volume flow is delivered. The heat transfer fluid volume flow is then increased again by the control device R using the circulation pump 9.

[0043] If, however, the circulation pump 9 pumps too much heat transfer fluid, the measured temperature difference between the temperature sensors t1 and t2 decreases, and the transferred power decreases again. The heat transfer fluid volume flow is then reduced again by the control device R using the circulation pump 9.

[0044] If this interaction is controlled by a PI controller, the heat transfer medium volume flow oscillates briefly to a stable value and the transmitted power fluctuates less and less until almost no oscillation is recognizable.

[0045] By means of the KVS valve 6, the heat transfer medium can be guided past the heat exchangers AB2 and AB1 via line 5 if more energy can be extracted from the exhaust air volume flow AV than is required in the supply air volume flow ZV.

[0046] For this purpose, the KVS valve 6 is controlled by means of an additional measurement of the supply air temperature, not shown here.

[0047] The valve 8 for the anti-icing protection is controlled by the measurement of the temperature sensor t2 or by a differential pressure gauge (not shown here) that measures the differential pressure across the exhaust air heat exchangers AB2 and AB1.

[0048] Furthermore, a first additional temperature sensor (not shown here) can be installed in the exhaust air volume flow AV before entering the exhaust air heat exchangers AB1, AB2. A second temperature sensor, also not shown here, can then be installed upstream of the supply air heat exchangers ZU1, ZU2 in the supply air volume flow ZV. This arrangement is selected if the system is also intended to be used for cooling recovery. If the temperature upstream of the supply air heat exchangers ZU1, ZU2 is higher than the temperature upstream of the exhaust air heat exchangers AB1, AB2, the heat transfer medium is passed through all heat exchangers in the cooling mode.

[0049] If the exhaust air temperature in cooling mode in front of the exhaust air heat exchangers AB1, AB2 is higher than the supply air temperature in front of the supply air heat exchangers ZU1, ZU2, the heat transfer medium is passed via line 5 as a bypass to the exhaust air extraction by means of the KVS valve 6.

[0050] If, in heating mode, the heat exchangers provided are so effective that the supply air volume flow ZV could become too warm for the existing requirements due to an excessive energy supply from the extract air volume flow AV, a third temperature sensor (not shown here) is used after the supply air heat exchangers ZU1, ZU2 in the supply air volume flow ZV.

[0051] Using the previously mentioned temperature measurements and by means of the control device R, a portion of the heat transfer medium can also be led through line 5 as the bypass for the exhaust air extraction.

[0052] In Figure 2Another arrangement of a closed-loop system not covered by the claims is shown, in which the heat transfer medium volume flow is controlled via a maximum possible temperature change between the exhaust air volume flow AV and the supply air volume flow ZV. The above-mentioned temperature change is also referred to as the heat recovery factor.

[0053] The circulation pump 9 in turn pumps the heat transfer medium through the supply air heat exchangers ZU1, ZU2, the valve 8 for the anti-icing protection, through the exhaust air heat exchangers AB2, AB1 and the KVS valve 6 back to the circulation pump 9.

[0054] In Figure 2 A temperature sensor 13 for detecting an exhaust air temperature t FOL in the exhaust air volume flow AV is arranged in its flow direction after the exhaust air heat exchanger AB2.

[0055] Furthermore, a temperature sensor 14 for detecting an exhaust air temperature t ABL in the exhaust air volume flow AV is arranged in its flow direction upstream of the exhaust air heat exchanger AB1.

[0056] Furthermore, a temperature sensor 15 for detecting an outside air temperature t AUS in the supply air volume flow ZV is arranged in its flow direction upstream of the supply air heat exchanger ZU1.

[0057] The measured values ​​from temperature sensors 13, 14, and 15 are fed to the control device R, which applies these measured values ​​to a continuous controller. The continuous controller changes the heat transfer medium flow rate by means of the circulation pump 9, whereby this flow rate can be either increased or decreased. The continuous controller records the measured temperature values ​​t FOL , t ABL , and t AUS from the temperature sensors 13, 14, and 15, and calculates the resulting degree of temperature change.

[0058] If the circulation pump 9 delivers too little heat transfer fluid, the temperature change rate of the air flow calculated from the measured temperature values ​​t FOL , t ABL , and t AUS becomes smaller because too little heat transfer fluid is delivered and thus too little power is transferred. The heat transfer fluid flow is then increased again by the circulation pump 9.

[0059] If, however, circulation pump 9 delivers too much heat transfer fluid, the temperature change rate of the air flow rates calculated from the measured temperature values ​​t FOL , t ABL , and t AUS also decreases, resulting in a decrease in the heat recovery capacity (heat recovery coefficient). The heat transfer fluid flow rate is then reduced again by circulation pump 9.

[0060] If this heat transfer process is controlled by a PI controller and whether the heat transfer medium flow rate decreases or increases is observed, the heat transfer medium flow rate quickly stabilizes and the transferred power fluctuates continuously less until almost no oscillation is noticeable.

[0061] The KVS valve 6 directs the heat transfer medium past the exhaust air heat exchangers AB2 and AB1 when more energy can be extracted from the exhaust air volume flow AV than is required in the supply air volume flow ZV according to the air treatment specifications. The KVS valve 6 is controlled using measured values ​​of the supply air temperature.

[0062] The valve 8 for the anti-icing protection is controlled by the measurement of the temperature sensor t2 or by a differential pressure gauge (not shown here) that measures the differential pressure across the exhaust air heat exchangers AB2 and AB1.

[0063] Furthermore, the arrangement according to Figure 2 Another temperature sensor, not shown here, must be used before entering the supply air heat exchangers ZU1, ZU2 in the supply air volume flow ZV if the device is also to be used for cold recovery.

[0064] If the temperature before the supply air heat exchanger ZU1 is higher than the extract air temperature t ABL before the extract air heat exchanger AB1, the heat exchanger is passed through all heat exchangers in the cooling case

[0065] If the exhaust air temperature t ABL in cooling mode is higher than the temperature upstream of the supply air heat exchanger ZU1, the heat exchanger is routed via line 5 as a bypass to the exhaust air extraction.

[0066] If the heat exchangers used in heating mode are so effective that the supply air volume flow ZV could become too warm due to an excessive energy supply from the extract air volume flow AV, the arrangement according to Figure 2Another temperature sensor, not shown here, can be used after the supply air heat exchangers ZU1, ZU2 in the supply air volume flow ZV.

[0067] Using the previously mentioned temperature measurements and by means of the control device R, a portion of the heat transfer medium can also be led through line 5 as a bypass to the exhaust air extraction.

[0068] In Figure 3 is an inventive arrangement of a circuit compound system with a temperature sensor t2 in the heat transfer line 3_before entering the exhaust air heat exchanger AB2 and a temperature sensor t1 in the heat transfer line 4 after leaving the exhaust air heat exchanger AB1, as in Figure 1 described, shown.

[0069] However, it is possible to couple cold from a cold fluid network or heat from a hot water network.

[0070] For this purpose, a heat exchanger 16 is coupled into the heat transfer line 4. The heat exchanger 16 is also coupled to a line 18 for pumped cold water for the passenger car. Thus, cooling energy can be transferred via the heat exchanger 16 into the closed-loop system on the heat transfer line 4, or the heat transfer medium can be cooled by means of the heat exchanger 16.

[0071] Furthermore, a heat exchanger 17 is coupled into the heat transfer line 4. The heat exchanger 17 is also coupled to a line 19 for pumped hot water (PWW). Thus, heat energy can be transferred via the heat exchanger 16 into the closed-loop system on the heat transfer line 4, or the heat transfer medium can be heated by means of the heat exchanger 17.

[0072] The degree of heat recovery from the extract air volume flow AV is somewhat lower with this method, but a large proportion of the electrical energy for the supply air fan V1 is saved because it is not necessary to arrange an additional cooler or heater in the supply air volume flow ZV for additional cooling or heating.

[0073] In Figure 4 another arrangement of a closed-loop system, not covered by the claims, with a control of the heat transfer medium volume flow on the basis of a maximum possible degree of temperature change of the exhaust air volume flow AV is shown, as can be seen from Figure 2 described.

[0074] However, there is a corresponding Figure 3 the possibility of coupling cold from a cold fluid network or heat from a hot water network.

[0075] For this purpose, a heat exchanger 16 is coupled into the heat transfer line 4. The heat exchanger 16 is also coupled to a line 18 for pumped cold water for the passenger car. Thus, cooling energy can be transferred via the heat exchanger 16 into the closed-loop system on the heat transfer line 4, or the heat transfer medium can be cooled by means of the heat exchanger 16.

[0076] Furthermore, a heat exchanger 17 is coupled into the heat transfer line 4. The heat exchanger 17 is also coupled to a line 19 for pumped hot water (PWW). Thus, heat energy can be transferred via the heat exchanger 16 into the closed-loop system on the heat transfer line 4, or the heat transfer medium can be heated by means of the heat exchanger 17.

[0077] The degree of heat recovery from the extract air volume flow AV is thus somewhat lower, but a large proportion of the electrical energy for the supply air fan V1 is saved because it is not necessary to arrange an additional cooler or heater in the supply air volume flow ZV for additional cooling or heating.

[0078] In Figure 5 Another arrangement of a closed-loop system not covered by the claims is shown, in which the heat transfer medium volume flow is controlled via a maximum possible temperature change between the supply air volume flow ZV and the exhaust air volume flow AV. The above-mentioned temperature change is also referred to as the heat recovery factor RWZ.

[0079] The circulation pump 9 in turn pumps the heat transfer medium through the supply air heat exchangers ZU1, ZU2, the valve 8 for the anti-icing protection, through the exhaust air heat exchangers AB2, AB1 and the KVS valve 6 back to the circulation pump 9.

[0080] In Figure 5 A temperature sensor 15 for detecting an outside air temperature t AUS in the supply air volume flow ZV is arranged in its flow direction upstream of the supply air heat exchanger ZU1.

[0081] Furthermore, a temperature sensor 16 for detecting a supply air temperature t ZUL in the supply air volume flow ZV is arranged in its flow direction upstream of the supply air heat exchanger ZU1.

[0082] Furthermore, temperature sensor 13 for detecting an exhaust air temperature t ABL in the exhaust air volume flow AV is arranged in its flow direction upstream of the exhaust air heat exchanger AB1.

[0083] The measured values ​​of the temperature sensors 15, 16, and 13 are fed to the control device R. By means of the control device R, these measured values ​​are switched to a continuous controller. The continuous controller changes the heat transfer medium volume flow by means of the circulation pump 9, whereby this flow can be either decreased or increased. The continuous controller records the temperature measured values ​​t SUPPLY, t EXHAUST, and t OUT from the temperature sensors 15, 16, and 13, and calculates the resulting degree of temperature change.

[0084] If the circulation pump 9 delivers too little heat transfer fluid, the temperature change rate of the air flow rates ZV, AV calculated from the measured temperature values ​​t SUP, t EXP, and t OUT will decrease because too little heat transfer fluid flow is delivered and thus too little power is transferred. The heat transfer fluid flow is then increased again by the circulation pump 9.

[0085] If, however, circulation pump 9 delivers too much heat transfer fluid, the temperature change rate of the air flow rates calculated from the measured temperature values ​​t SUPPLY, t EXHAUST, and t OUT also decreases, resulting in a decrease in the heat recovery capacity (heat recovery coefficient). The heat transfer fluid flow rate is then reduced again by circulation pump 9.

[0086] If this heat transfer process is controlled by a PI controller and whether the heat transfer medium flow rate decreases or increases is observed, the heat transfer medium flow rate quickly stabilizes and the transferred power fluctuates continuously less until almost no oscillation is noticeable.

[0087] The KVS valve 6 directs the heat transfer medium past the exhaust air heat exchangers AB2 and AB1 when more energy can be extracted from the exhaust air volume flow AV than is required in the supply air volume flow ZV according to the air treatment specifications. The KVS valve 6 is controlled using measured values ​​of the supply air temperature.

[0088] The valve 8 for the anti-icing protection is controlled by the measurement of the temperature sensor t2 or by a differential pressure gauge (not shown here) that measures the differential pressure across the exhaust air heat exchangers AB2 and AB1.

[0089] Furthermore, the arrangement according to Figure 2 Another temperature sensor, not shown here, must be used before entering the supply air heat exchangers ZU1, ZU2 in the supply air volume flow ZV if the device is also to be used for cold recovery.

[0090] If the temperature before the supply air heat exchanger ZU1 is higher than the extract air temperature tABL before the extract air heat exchanger AB1, the heat exchanger is passed through all heat exchangers in the cooling case

[0091] If the exhaust air temperature tABL in cooling mode is higher than the temperature upstream of the supply air heat exchanger ZU1, the heat exchanger is routed via line 5 as a bypass to the exhaust air extraction.

[0092] If the heat exchangers used in heating mode are so effective that the supply air volume flow ZV could become too warm due to an excessive energy supply from the extract air volume flow AV, the arrangement according to Figure 2 Another temperature sensor, not shown here, can be used after the supply air heat exchangers ZU1, ZU2 in the supply air volume flow ZV.

[0093] Using the previously mentioned temperature measurements and by means of the control device R, a portion of the heat transfer medium can also be led through line 5 as a bypass to the exhaust air extraction.

[0094] In Figure 6 a possible control scheme for the method according to the invention according to claim 1 is shown, including temperature measurements of the heat transfer medium and a volume flow measurement according to the method of magnetic-inductive volume measurement MID.

[0095] First, the parameters intended for use within the procedure are listed. These are: Dal is the known or set speed of the circulation pump 9 Dal is the previously set speed of the circulation pump 9 Qal is the previous power ro is the density of the heat transfer medium cal is the specific heat capacity of the heat transfer medium Sum is the summand to be used in each case tEIN is the measured inlet temperature of the heat transfer medium at the exhaust air heat exchangers AB1, AB2 tAUSA is the measured outlet temperature of the heat transfer medium after the exhaust air heat exchangers AB1, AB2 Val is the measured volume flow of the heat transfer medium Direction is the continuous variable of the direction of change of the speed of the circulation pump between D and Dalt.

[0096] The control process is started with specified parameters D, Dalt, Summ, Q and the direction setting [GREATER] for the ratio of the speeds D, Dalt of the circulation pump 9. These default values ​​are selected based on empirical values.

[0097] This allows the control system to be enabled. This enablement is based on activation signals for commissioning the closed-loop system, which can be executed by the operator or carried out time-dependently using a control system.

[0098] In the following, the description of the control process sequence indicates how the control process is forwarded with the process data, whereby only the term process is used for forwarding.

[0099] From the starting point, the process is directed to a branching point [1] via the [ENABLE] input. There, the [ENABLE] value is checked, and the process is directed to a branching point [2] via the [YES] output, where a comparison of the speeds D and Dalt takes place.

[0100] If the control process is to be aborted in the meantime because the plant is to be shut down for various reasons, the process is directed to the end of the control in the branch point [1] via the output [NO].

[0101] At branch point [2], the process is forwarded in the direction [JA] to a branch point [3] based on the default values ​​D / Dalt.

[0102] For comparing the transferred power, no reference value is yet available for Q. Therefore, Q is greater than Qold, and the process is routed to a settlement point at branching point [3] via output [YES]. There, the speed Dalt of circulation pump 9 is replaced by the value of D, and the value of D is increased by the summand. The new values ​​are fed back into the process after output [NO] of branching point [3] and forwarded to the next branching point [4].

[0103] Since the speed D is now to be increased, the variable direction [GREATER] is to be assumed and the process is passed through to the output [NO] in the branching point [4] when the direction is queried and fed to the process with the variable direction as [GREATER].

[0104] The process data are then fed back into the process before the temperatures tON and tOFF as well as the volume flow V are recorded by the volume flow meter.

[0105] Based on this, the process, including the temperature measured values ​​tON, tOFF and the volume flow V, is subjected to a performance calculation.

[0106] Here, a Δt is calculated from tON and tOFF. The value Qold is replaced by the known value Q. The density r0 and the specific heat capacity c of the heat transfer fluid can be recalculated. The power is then recalculated using the formula Q = V * r0 * c * Δt / 3.6.

[0107] From the performance calculation, the process is forwarded to a branching point [7]. At the branching point [7], the summand SUMM is checked for an excessive reduction compared to the value 0.01. If this value is reached or exceeded, the summand SUMM is increased to 0.02.

[0108] The process is then forwarded to a branching point [8].

[0109] At the branching point [8], the power Q is checked for an excessive increase compared to a value of power Qalt increased by a factor of 1.2. This is necessary in the event of a change in the process framework data, for example, in the event of an interim increase in the exhaust air volume flow AV, in order to reach the desired control range more quickly. For this purpose, the summand SUMM would be increased here.

[0110] In the normal control process, the process is forwarded at the output [NO] of the branching point [8] and fed back into the control process before the branching point [1].

[0111] If the [ENABLE] signal is still present, the process is routed back to branch point [2]. Since the current speed D is still greater than the previous speed Dalt, the process is routed back to branch point [3] via the [YES] output.

[0112] In the current control process, starting from the branching point [3], there are the following options for continuing the control process: a) The current power Q is greater than the previous power Qalt. Then, as already described, the speed D is increased by the summand via the [YES] output. The direction variable is again [GREATER]. b) The current power Q is less than the previous power Qalt. Then, at a calculation point, the speed D is reduced by the summand via the [NO] output. If the direction variable is then [SMALLER], the process is forwarded to another calculation point via the [YES] output. There, the summand is reduced by a factor of 0.5. The process is then forwarded with the direction variable as [GREATER]. The direction variable remains at [GREATER].

[0113] The process is then fed back to the power calculation with the temperature measurements and the volume flow measurement and is routed via the branching points [7] and [8] back to the start of the control process and, at [RELEASE], to the branching points [1] and [2].

[0114] At the branching point [2] the speed D is now, according to the previous determination a) greater or faster than Dalt and according to the previous determination b) the speed D is smaller or slower than Dalt.

[0115] This results in two alternatives for continuing the control process, whereby the variable direction is processed according to its previous setting to the value [GREATER] or [SMALLER].

[0116] If D is faster than Dalt according to a), the process is routed at branch point [2] via output [YES] to branch point [3]. There, the determination variants a) and b) are processed, and the process is fed into the performance calculation with the variable direction as [GREATER]. This value is carried over into this cycle by the control process.

[0117] If D is slower than Dalt according to b), the process is routed via the [NO] output at branch point [2] to a branch point [5]. There, a performance comparison between Q and Qold is performed.

[0118] In the current control process, starting from the branching point [5], there are the following options for continuing the control process: c) The current power Q is greater than the previous power Qalt. The process then proceeds via the [YES] output to a settlement point where the previous speed is replaced by speed D. The speed D is further reduced by the summand with the original value. The process now proceeds to a branching point [6]. d) The current power Q is less than the previous power Qalt. The process then proceeds via the [NO] output to replace the previous speed Dalt in a further settlement point with speed D and the speed D is increased by the summand. The variable Direction is still [GREATER] and the process is forwarded via the [YES] output to a further settlement point. There the summand SUMM is reduced by a factor of 0.5. The process is then forwarded with the variable Direction as [SMALLER], whereby this value is used in the next control cycle.

[0119] Since the variable direction now has the value [LESS] after the changes in the speeds D, Dalt, the process is forwarded via the [NO] output with the variable direction set to [LESS]. The process data is then fed back into the power calculation via the temperature and volume flow determination.

[0120] The process is now led back to the beginning of the control process via the branching points [7] and [8] and at [RELEASE] to the branching points [1] and [2]

[0121] From the alternatives a) to d) of the control process, the process is continued by a respective power comparison, starting from the comparison of the speeds D, Dalt at the branching point [2] in such a way that a continuous increase in the power transmission results.

[0122] In the control process, a further increase in the speed of circulation pump 9 is possible if this results in a further increase in power transmission. On the other hand, if the power transmission decreases, a speed increase or a speed decrease of circulation pump 9 is possible, depending on the direction in which a further increase in power transmission results.

[0123] The speed changes are achieved by applying the summand SUMM accordingly. Furthermore, to execute a transient response of the control process, the summand SUMM is reduced by the maximum degree of power transfer. In the example, the summand SUMM is halved in each case, but the reduction is limited to 0.02 at the branching point [7].

[0124] This results in an asymptotic approximation of the control process to the maximum possible power transfer with a continuously decreasing amplitude, which remains limited to a value corresponding to the summand SUMM = 0.02 in order to continue to enable true control.

[0125] In Figure 7 a possible control scheme for another method not covered by the claims is shown, including temperature measurements in the exhaust air volume flow AV and in the supply air volume flow ZV via a heat recovery factor RWZ that can be determined from this.

[0126] First, the parameters intended for use within the procedure are listed. These are: Dal is the known or set speed of the circulation pump 9 Dal is the previously set speed of the circulation pump 9 RWZa is the previous heat recovery factor RWZ RWZ is the new heat recovery factor RWZ SUMMas the summand for changing the speed of the circulation pump 9 tFOL is the exhaust air temperature tABL is the extract air temperature tAUAs the outside temperature Direction as a variable for changing the direction of the speed of the circulation pump 9 between D and Dalt.

[0127] The control process is started with specified parameters D, Dalt, Summ, RWZ and the direction setting [GREATER] for the ratio of the speeds D, Dalt of the circulation pump 9. These default values ​​are selected based on empirical values.

[0128] The control process according to Figure 7 is structured similarly to the control process according to Figure 6 .

[0129] Therefore, only the differences are mentioned here.

[0130] It is essential that comparisons of the heat recovery coefficients RWZ and RWZa now take place in branching points [3], [5], [7] and [8].

[0131] Furthermore, after recording the exhaust air temperature tFOL and the extract air temperature tABL in the extract air volume flow AV and the outside temperature tAUS in the supply air volume flow ZV, a heat recovery coefficient calculation is performed. The previous heat recovery coefficient RWZa is replaced by the current heat recovery coefficient RWZ. The current heat recovery coefficient RWZ is then recalculated using the formula RWZ = (tABL - tFOL) / (tABL - tAUS) * 100.

[0132] The process control takes place taking these parameters into account analogously to the control process according to Figure 6 .

[0133] This initially applies to the entry into the control process. At a branching point [2], the process is forwarded toward [JA] of the branching point [3] based on the default values ​​D and Dalt.

[0134] For the comparison of the heat recovery coefficients RWZ and RWZa, no comparison value RWZa is yet available for RWZ. Therefore, RWZ is greater than RWZa, and the process is routed to a settlement point at branching point [3] via output [YES]. There, the speed Dalt of circulation pump 9 is replaced by the value of D, and the value of D is increased by the summand. The new values ​​are fed back into the process after output [NO] of branching point [3] and forwarded to the next branching point [4].

[0135] If the previous variable direction was [SMALLER], the summand SUMM is multiplied by 0.5. Whenever the previous variable direction changes, the summand SUMM is halved.

[0136] The process is returned to the starting point via the branching points [7] and [8]. There, the summand SUMM can initially be limited to 0.02. Furthermore, the summand SUMM can also be increased if the heat recovery factor RWZ has increased significantly, for example, because the exhaust air flow rate AV has been changed.

[0137] In the current control process, the options a) and b) for continuing the control process are now determined from the branching point [3] as follows: a) The current heat recovery coefficient RWZ is greater than the previous heat recovery coefficient RWZa. Then, as already described, the speed D is increased by the summand via the [YES] output. The variable direction is again [GREATER]. b) The current heat recovery coefficient RWZ is less than the previous heat recovery coefficient RWZa. Then, at a settlement point, the speed D is reduced by the summand via the [NO] output. The process is now forwarded to another settlement point via the [YES] output. There, the summand is multiplied by the factor 0.5 and therefore reduced. The process is then forwarded with the variable direction as [GREATER]. Finally, in the current control process, options c) and d) for continuing the control process are determined from branching point [5] as follows: c) The current heat recovery coefficient RWZ is greater than the previous heat recovery coefficient RWZa.The process is then passed on via the [YES] output to a settlement point where the previous speed is replaced by speed D. The speed D is then reduced by the summand SUMM with the original value. The process is now passed on to a branching point [6]. d) The current heat recovery factor RWZ is less than the previous heat recovery factor RWZa. The process is then passed on via the [NO] output to a further settlement point where the previous speed Dalt is replaced by speed D and the speed D is increased by the summand SUMM. The process is now passed on via the [YES] output to a further settlement point. There the summand SUMM is multiplied by the factor 0.5 and therefore reduced. The process is then passed on with the variable direction as [LESS].

[0138] From the alternatives a) to d) of the control process, the process is guided in the direction that leads to an increase in the heat recovery factor RWZ by comparing the respective heat recovery factors RWZ, RWZa.

[0139] In this case, a further increase in the speed of circulation pump 9 is possible if this results in a further increase in the heat recovery factor RWZ. On the other hand, if the heat recovery factor RWZ decreases, a speed increase or a speed decrease of circulation pump 9 is possible, depending on the direction in which a further increase in the heat recovery factor RWZ results.

[0140] The speed changes are achieved by applying the summand SUMM accordingly. Furthermore, to execute a transient response of the control process, the summand SUMM is reduced by the maximum value of the heat recovery factor RWZ. In the example, the summand SUMM is halved in each case, but the reduction is limited to 0.02 at the branching point [7].

[0141] This results in an asymptotic approximation of the control process to the maximum possible heat recovery factor RWZ with a continuously decreasing oscillation amplitude, which remains limited to a value corresponding to the summand SUMM = 0.02 in order to continue to enable real control.

[0142] The regulatory process according to Figure 7 is carried out accordingly if the heat recovery factor RWZ is in an arrangement according to Figure 5is calculated from an outside air temperature tAUL and a supply air temperature tZUL in the supply air volume flow ZV as well as an extract air temperature tABL in the extract air volume flow AV.

[0143] The core of the invention is a method for controlling a heat transfer medium volume flow in a closed-loop system, whereby a maximum possible power transfer via the heat transfer medium is provided.

[0144] Such a method can be carried out according to claim 1 by means of temperature detection in the heat transfer medium before and after passage through the exhaust air heat exchangers AB1, AB2 and a measurement of the heat transfer medium volume flow.

[0145] Alternatively, another method not covered by the claims can be implemented using temperature measurements to determine the maximum possible temperature change between the exhaust air volume flow AV and the supply air volume flow ZV. The control can be expanded according to the respective requirements.

[0146] A control according to an embodiment not covered by the claims can thus also be implemented in a control system consisting of two combined circulation systems, not primarily by controlling the circulation pump 9, but by distributing the heat energy using a three-way valve and volume control valves in order to maintain the maximum energy yield for the respective operating case. The circulation pump 9 only needs to be controlled in relation to the total power requirement, which varies from operating case to operating case.

Claims

1. Method for regulating the flow of a heat transfer volume in an integrated circuit system with at least one supply air heat exchanger (ZU1, ZU2) arranged in a supply air volume flow (ZU1, ZU2) and at least one exhaust air heat exchanger (AB1, AB2) arranged in an exhaust air volume flow (AV), wherein the supply air heat exchanger(s) (ZU1, ZU2) and the exhaust air heat exchanger(s) (AB1, AB2) are coupled by means of heat transfer pipes (3, 4) in such a way that the heat transfer medium is movable by means of at least one circulation pump (9) and can be conveyed successively through all supply air heat exchangers (ZU1, ZU2) arranged in the supply air volume flow (ZU1, ZU2) and thereafter through all exhaust air heat exchangers (AB1, AB2) arranged in the exhaust air volume flow (AV), characterised in that the integrated circuit system is operated in such a way that, on the basis of temperature measurements of the heat transfer volume flow before the entry into the exhaust air heat exchanger(s) (AB1, AB2) and after the exit from the exhaust air heat exchanger(s) (AB1, AB2), as well as a parallel volume flow measurement of the heat transfer volume flow (V) by changing the speed of the circulation pump (9), the heat transfer volume flow is regulated in such a way that by means of the measured heat transfer volume flow (V) and the temperature measurements, a maximum possible power transfer by means of the heat transfer medium is determined and that the speed of the circulation pump (9) and thus the heat transfer volume flow are regulated in such a way that a maximum possible power transfer is carried out by means of the heat transfer medium.

2. Method according to claim 1,characterized by the fact that the heat transfer volume flow in the integrated circuit system is regulated on the basis of temperature measurement values of the heat transfer medium before the entry of the exhaust air volume flow into the exhaust air heat exchanger(s) (AB1, AB2) and after the exit from the exhaust air heat exchanger(s) (AB1, AB2) as well as a volume flow measurement of the heat transfer medium volume flow (V) carried out in parallel in such a way that if an increasing power transfer is detected of the heat transfer medium of the heat transfer volume flow by means of the circulation pump (9) is changed by means of the heat transfer medium after a previously decreasing power transfer by means of the heat transfer medium in contrast to a previously made volume flow change or is changed by a smaller amount compared to a previously made volume flow change after a previously increasing power transfer by means of the heat transfer medium.

3. Integrated circuit system for carrying out a process for regulating a heat transfer volume flow with at least one supply air heat exchanger (ZU1, ZU2) arranged in a supply air volume flow (ZV) and at least one exhaust air heat exchanger (AB1, AB2) arranged in an exhaust air volume flow (AV), wherein the supply air heat exchanger(s) (ZU1, ZU2) and the exhaust air heat exchanger(s) (AB1, AB2) are coupled by means of heat transfer pipes (3, 4) in such a way that the heat transfer medium is movable by means of at least one circulation pump (9) and can be conveyed successively through all supply air heat exchangers (ZU1, ZU2) arranged in the supply air volume flow (ZV) and thereafter through all exhaust air heat exchangers (AB1, AB2) arranged in the exhaust air volume flow (AV), wherein in a heat transfer line (3) a temperature sensor (t2) is used before the heat transfer medium enters the exhaust air heat exchanger (AB1, AB2), that in a heat transfer line (4) a temperature sensor (t1) is arranged after the heat transfer medium has left the exhaust air heat exchanger(s) (AB1, AB2), characterized by the fact that the integrated circuit system is set up for carrying out the method according to claim 1, that a volume flow measuring device (12) is provided assigned to the circulation pump (9) and that a control device (R) is provided in conjunction with the temperature sensors (t1, t2), the volume flow measuring device (12) and the circulation pump (9), in such a way that on the basis of the measured values determined by changing the heat transfer volume flow, a decreasing power transfer of the heat transfer medium may be regulated so that the rotating speed is increased or reduced at the circulation pump (9), depending on the direction in which a following increase in power transfer occurs.

4. Arrangement comprising an integrated circuit system according to claim 3 and several ventilation units.

5. Use of an integrated circuit system according to claim 3 for dehumidification of an air volume flow.