DE102010030663B4 - Method for operating a vehicle temperature control device - Google Patents

Abstract

Method for operating a vehicle temperature control device (G), in which method the temperature control output (Qzu) of the vehicle temperature control device (G) as a function of the rate of change of the temperature (T) of a vehicle interior as a system area (S) to be temperature-controlled and a power balance variable (B) of the temperature-controlled system System area (S) is set, comprising the measures: a) determining a target rate of change of the temperature Toll (t) of the system area (S) to be tempered for a calculation cycle (t), b) determining the tempering performance (Qzu (t)) of the Vehicle temperature control device (G) for a calculation cycle (t) on the basis of a target rate of change of the temperature (Toll (t)) of the system area (S) to be tempered for this calculation cycle (t) and on the basis of the power balance variable (B (t-1 )) of the system area (S) for a preceding calculation cycle (t-1) and determining the power budget variable (B (t-1)) of the system area (S) to be tempered for the preceding n the calculation cycle (t-1) based on the temperature control performance (Qzu (t-1)) of the vehicle temperature control device (G) for the previous calculation cycle and the rate of change of the temperature (T (t-1)) of the system area (S) to be temperature controlled in previous calculation cycle (t-1) according to the following relationships: Qzu (t) = K × Tsoll (t) + B (t − 1), B (t − 1) = (Qzu (t − 1) −K × T ( t − 1)), where: K is a predetermined factor, Toll (t) is the target rate of change of the temperature of the system area to be tempered (S) for this calculation cycle (t), and B (t-1) is the power budget variable of the system area (S ) for the previous calculation cycle (t-1), c) operating the vehicle temperature control device (G) in the calculation cycle (t) in such a way that the temperature control performance (Qzu (t)) determined for this calculation cycle (t) is provided.

Description

The present invention relates to a method for operating a vehicle temperature control device.

Temperature control devices known from the prior art with temperature control are equipped with a plurality of temperature control levels which can be set or switched between. For example, vehicle heaters are known which are operated as auxiliary heaters or as auxiliary heaters in order to ensure sufficient heating, for example of the vehicle interior, before or during the operation of a vehicle. These vehicle heaters can be fuel-operated and, depending on the required heat demand, different heat output levels can be set or switched between them, with high heat demand with higher heat output levels and lower heat demand with lower heat output levels.

In particular with temperature control devices with a plurality of temperature control power levels, but also with temperature control devices with continuously adjustable temperature control power, the problem arises that the temperature control power control causes larger deviations between the measured value of a temperature and a target value of this temperature and / or larger deviations between a determined rate of change the temperature and a target rate of change of this temperature can occur. Such undesirable deviations can occur, for example, during transition phases to a temperature value to be reached (cooling or heating phase) or when a temperature is to be kept constant after a desired value has been reached, for example following a cooling or heating phase.

From the EP 0 192 228 A2 a method for regulating the temperature in rooms is known. In this known method, the temperature is recorded and the first or higher derivative of the temperature with respect to time is determined. A target value band is defined for these time derivatives, and a heat or cold source is operated in such a way that deviations in the derivatives from the assigned target value band are eliminated.

The object of the present invention is to provide a method for operating a vehicle temperature control device which makes it possible to set the temperature in a vehicle interior as a system area to be temperature controlled in a simple, precise and reliable manner.

According to the invention, the object of the present invention is achieved by a method for operating a vehicle temperature control device according to claim 1, in which method the temperature control performance of the vehicle temperature control device is set as a function of the rate of change of the temperature of the system area to be temperature controlled and a power balance variable of this system area.

Here, as above and below, the rate of change of a variable is understood to mean the derivation of this variable with respect to time, that is to say approximately the absolute change in this variable per unit of time. By taking into account the rate of change of the temperature of the system area to be temperature-controlled and a power balance variable of this system area, temperature control output control for the system area is possible, through which undesired deviations between a measured temperature of the system area to be temperature-controlled and a setpoint temperature of the system area to be temperature-controlled are easier, more precise and more reliable Way are largely avoidable.

The power balance of the system area to be temperature-controlled is determined by the power not entered in the system area and / or from the system area by operating the temperature control unit.

The power that is not entered into the system area by operating the temperature control device and / or a power discharged from the system area by a media flow and / or a power loss in the system area contribute to the power balance of the system area to be temperature-controlled.

The power balance of the system area to be temperature-controlled for a respective calculation cycle is determined on the basis of the temperature control performance of the vehicle temperature control device for this calculation cycle and the rate of change of the temperature of the system area to be temperature-controlled for this calculation cycle. By additionally taking into account the rate of change of the temperature of the system area to be tempered in a respective calculation cycle, which can easily be determined, for example, by an arrangement comprising at least one temperature sensor, a memory and a calculation unit, the power balance variable of the system area can be determined even more precisely and thus the temperature control performance of the Temperature control unit can be set even more precisely.

The temperature control performance of the temperature control device for a calculation cycle is based on the performance balance of the system area to be temperature controlled for a previous one Calculation cycle determined. By taking into account the power balance variable for a preceding calculation cycle, the temperature control performance of the vehicle temperature control device for a calculation cycle is determined with improved accuracy and the other advantages of the invention are also achieved even better.

In the method according to the invention, the temperature control performance of the temperature control device for a calculation cycle is determined on the basis of a target rate of change of the temperature of the system area to be temperature controlled for this calculation cycle. By taking into account a target rate of change of the temperature for the system area to be tempered for the calculation cycle, the temperature control performance of the temperature control device for the calculation cycle can be determined with further improved accuracy and the other advantages of the invention are achieved even better.

ermittelt, wobei K ein vorbestimmter Faktor, T_soll(t) die Soll-Änderungsrate der Temperatur des zu temperierenden Systembereichs für diesen Berechnungszyklus und B(t-1) die Leistungsbilanzgröße des Systembereichs für den vorangehenden Berechnungszyklus ist.In the process, the temperature control performance of the temperature control device is used for a calculation cycle on the basis of the relationship $${\text{Q}}_{\text{to}}\left(\text{t}\right)=\text{K}\times {\text{T}}_{\text{should}}\left(\text{t}\right)+\text{B.}\left(\text{t}-1\right)$$

determined, where K is a predetermined factor, T _soll (t) is the nominal rate of change of the temperature of the system area to be tempered for this calculation cycle and B (t-1) is the power budget variable of the system area for the previous calculation cycle.

wobei H_ein(t-1) die nicht durch Betreiben des Temperiergerätes in den Systembereich eingetragene Leistung für den vorangehenden Berechnungszyklus, H_aus(t-1) die durch einen Medienstrom aus dem Systembereich ausgetragene Leistung für den vorangehenden Berechnungszyklus und Q_verl(t-1) die Verlustleistung des Systembereichs für den vorangehenden Berechnungszyklus ist, und wird gemäß den Prinzipien der vorliegenden Erfindung wie folgt ermittelt: $$\text{B}\left(\text{t}-1\right)=\left({\text{Q}}_{\text{zu}}\left(\text{t-1}\right)-\text{K}\times \text{T}\left(\text{t}-\text{1}\right)\right),$$

wobei K der vorbestimmte Faktor ist, Qzu(t-1) die Temperierleistung des Fahrzeugtemperiergeräts für den vorangehenden Berechnungszyklus ist und T(t-1) die Änderungsrate der Temperatur des zu temperierenden Systembereichs in den vorangehenden Berechnungszyklus ist.The power balance parameter for the preceding calculation cycle is basically composed as follows: $$\text{B.}\left(\text{t}-1\right)=-{\text{H}}_{\text{a}}\left(\text{t}-1\right)+{\text{H}}_{\text{out}}\left(\text{t}-1\right)+{\text{Q}}_{\text{lost}}\left(\text{t}-\text{1}\right),$$

where H is _a (t-1) is not registered by operation of the temperature in the system area of power for the previous calculation cycle, H _of (t-1) is discharged through a media stream from the system area power for the previous calculation cycle, and Q _ET (t- 1) is the power dissipation of the system area for the previous computation cycle, and is determined according to the principles of the present invention as follows: $$\text{B.}\left(\text{t}-1\right)=\left({\text{Q}}_{\text{to}}\left(\text{t-1}\right)-\text{K}\times \text{T}\left(\text{t}-\text{1}\right)\right),$$

where K is the predetermined factor, Qzu (t-1) is the temperature control performance of the vehicle temperature control device for the previous calculation cycle and T (t-1) is the rate of change of the temperature of the system area to be temperature controlled in the previous calculation cycle.

As a result, a rate of change in the temperature of the system area to be tempered can be achieved in the system area by determining the temperature control output of the temperature control device necessary to bring it about, taking into account the relevant heat output components entered in the system area and discharged from it.

In order to prevent undesired deviations from a setpoint temperature and / or from a setpoint rate of change of the temperature in a system area during temperature control, it is necessary to consider heat outputs entered in the system area and discharged from the system area. The following services are of particular importance: Heat output entered into the system area by operating a temperature control unit or removed from the system area by operating the temperature control unit, heat output entered into the system area through a media flow or removed from the system area through a media flow, as well as heat output entries into the system area and heat output outputs from the system area, which are neither caused by the operation of a temperature control unit nor by a media flow, such as B. absorbed by radiation from the environment of the system area or emitted to this environment heat output. The more precisely these heat output components can be measured or estimated, the more precisely the change in the internal energy that has occurred in the system area during a certain period of time can be determined. If, in addition, the heat capacities and masses of the materials present in the system area are known, the resulting temperature change in the system area can be calculated. Furthermore, this consideration makes it possible to adjust the thermal energy entered by the temperature control device or discharged by the temperature control device in such a way that a desired temperature change and / or temperature change rate is achieved within a certain period of time.

It should be mentioned that achieving a desired temperature change and / or rate of temperature change in the system area within a certain period requires that any desired amount of heat can be supplied or removed during this period, i.e. that the desired amount of heat to be supplied is continuously adjustable. This can ideally be achieved by a temperature control device with continuously or at least finely adjustable temperature control. The method according to the invention can also be advantageous for operating vehicle temperature control devices with a plurality of temperature control power levels can be used. If none of the adjustable temperature control power levels can provide the desired temperature control power, the method makes it possible, for example, to regulate the temperature control power for a calculation cycle to a level whose temperature control power is only slightly lower than that for realizing a certain temperature and / or the rate of change in the temperature of the system area to be controlled is the required temperature control performance of the vehicle temperature control device, and thereby to achieve the advantages according to the invention. This succeeds all the better, the smaller the distance between adjacent temperature power levels is.

It should also be mentioned that the heat output entered into the system area by a vehicle temperature control device or discharged from it by the temperature control device, as well as the heat output entered into the system area by a regulated media flow or discharged from the system area by the media flow, can be determined easily and relatively precisely, whereas heat outputs that are entered into the system or discharged from the system during a certain period of time through thermal conduction, radiation or convection, which are not caused by a temperature control device or a regulated media flow, only with great technical effort and / and only very imprecisely through estimates can be determined. It is therefore an advantage of the method according to the invention for operating a vehicle temperature control device that the temperature control output of the temperature control device is set as a function of the rate of change in the temperature of the system area to be temperature controlled and a power balance variable of this system area, without such technical effort and / or estimates being required.

The method can advantageously be used not only in a fresh air mode, but also in a recirculation mode. In this case, in the above consideration, the components assigned to the fresh air media flow are omitted or have to be replaced by corresponding components assigned to the circulating air media flow. The method according to the invention can also be used advantageously in particular when sudden heat power inflows into the system area to be tempered or sudden heat power outflows from this occur. This is the case, for example, when the temperature control device is used both for temperature control of an interior of a vehicle and for temperature control of an engine present in the vehicle. For such vehicle temperature control devices, for example when they are used to heat the vehicle interior, a temporary drop in the actual temperature curve caused by the preheating of the vehicle engine can be observed.

It should also be noted that there are a plurality of methods that can advantageously be used within the scope of the invention for determining an actual rate of change of the temperature on the basis of temperature sensor values. For example, a rate of change T (t) of the temperature O (t) of the system area to be tempered can be approximately determined for a calculation cycle t as the quotient of a temperature difference Θ (t) -Θ (t-1) and determined in relation to the previous calculation cycle the time interval t- (t-1) between the two calculation cycles.

An embodiment of the present invention will be described hereinafter with reference to the accompanying 1 described in detail, which schematically depicts the system area to be temperature-controlled, the heat input and output into and out of this, a temperature control device and a temperature sensor according to this embodiment.

The 1 shows a system area S to be tempered, which is the interior of a vehicle to be heated. That on the basis of 1 The illustrative embodiment of a method for operating a vehicle temperature control device is explained for the case that the temperature of the vehicle interior is above the vehicle exterior temperature. 1 shows a preferably fuel-operated heater G for the vehicle for heating the vehicle interior and a temperature sensor D which periodically measures the air temperature in the vehicle interior S at short intervals. The heating power Qzu supplied to the interior by the heater acting as the vehicle temperature control device G is shown as an arrow in the direction of the interior.

In 1 the heater is shown in fresh air mode, where H _a denotes the heat output not entered into the interior by operating the heater, which includes in particular the heat output supplied by a heated fresh air flow and the heat supplied by solar radiation, and where house the heat output removed from the interior by the exhaust air flow designated. Other heat output outflows from the vehicle interior that are not caused by the operation of the heater and not caused by the media flow are in 1 represented by the power loss Q _{verl of} the system area. In particular, they include power losses due to heat dissipation from the vehicle interior to the surroundings of the vehicle. It should be noted that when the method is applied to an air conditioning device, for example an air conditioning system for a vehicle, the direction of the in 1 as an arrow illustrated heat output flow Q _to reversed. The direction of the power _{flow Q verl shown as an arrow} reverses as soon as the interior temperature is below the outside temperature.

In the one on hand of 1 The explained embodiment of the method according to the invention is the heat output that is supplied by the heater in a calculation cycle t so that a predetermined temperature and / or rate of change of the temperature in the vehicle interior is reached by a subsequent calculation cycle t + 1, preferably based on the temperature sensor The temperatures O (t) and 0 (t-1) measured in the calculation cycles t and t-1 are determined. In the exemplary embodiment, the calculation cycles are preferably synchronized with the time sequence of the measurements of the temperature sensor and, more preferably, of the same duration.

The setpoint temperature and / or setpoint rate of change of the temperature is preferably determined from information provided to the temperature control device by a user of the temperature control device before the start of the method.

zugrunde, wobei die einzelnen Terme jeweils den vorangehend erläuterten entsprechen. Der Temperaturgradient für Berechnungszyklus t wird vorzugsweise berechnet als $$\text{T}\left(\text{t}\right)=\left(\mathrm{\Theta }\left(\text{t}\right)-\mathrm{\Theta }\left(\text{t}-1\right)\right)/\left(\text{t}-\left(\text{t}-1\right)\right).$$

The relationship between the thermal power Qzu (t) supplied to the vehicle interior by the heater in the calculation cycle t and the temperature gradient T (t) resulting in the vehicle interior is preferably $${\text{Q}}_{\text{to}}\left(\text{t}\right)=\text{K}\times \text{T}\left(\text{t}\right)+\left({\text{Q}}_{\text{to}}\left(\text{t}-\text{1}\right)-\text{K}\times \text{T}\left(\text{t}-\text{1}\right)\right)$$

The individual terms correspond to those explained above. The temperature gradient for calculation cycle t is preferably calculated as $$\text{T}\left(\text{t}\right)=\left(\mathrm{\Theta }\left(\text{t}\right)-\mathrm{\Theta }\left(\text{t}-1\right)\right)/\left(\text{t}-\left(\text{t}-1\right)\right).$$

Alternatively, it can be calculated, for example, as (0 (t) -0 (t-2)) / (t- (t-2)), where O (t-2) is the value determined by the temperature sensor in a calculation cycle t-1 preceding Calculation cycle t-2 is the temperature of the system area measured, or, for example, as a weighted average of a plurality of temperature gradients, possibly determined in different calculation cycles.

The method for operating a temperature control device can preferably include the following steps: In a calculation cycle t, the temperature sensor measures the temperature O (t) of a system area to be tempered, preferably a vehicle interior to be heated, and this value is stored. The rate of change in the temperature of the previous calculation cycle t-1 is preferably determined in the calculation cycle t by reading out the stored temperature measurement values Θ (t-1) and Θ (t-2) of the vehicle interior for previous calculation cycles t-1 and t-2 as $$\text{T}\left(\text{t}-\text{1}\right)=\left(\mathrm{\Theta }\left(\text{t}-\text{1}\right)-\mathrm{\Theta }\left(\text{t}-2\right)\right)/\left(\text{t}-\text{1}-\left(\text{t}-2\right)\right).$$

By multiplying the rate of change of the temperature T (t-1) for the calculation cycle t-1 by the predetermined factor K, the rate of change of the internal energy U (t-1) for the calculation cycle t-1 is calculated. This rate of change U (t-1) is then subtracted from the heating power Qzu (t-1) of the heater for calculation cycle t-1, which was determined and stored in calculation cycle t-1 from the settings of the heater. The result is the power balance variable B (t-1) = Qzu (t-1) -U (t-1) of the calculation cycle t-1. Then the power balance variable B (t-1) and the product of the predetermined target rate of change T _soll (t) of the temperature of the calculation cycle t and the factor K are added. The result K x T _soll (t) + B (t-1) indicates the heating power Qzu (t) of the heater to be supplied to the temperature in the calculation cycle t in order to achieve the desired rate of change T _{soll (t).} If the heater enables stepless heating power control, this heating power Qzu (t) is supplied in a next step in the calculation cycle t and its value is saved. If the heater does not allow infinitely variable heating output control, that of the adjustable heating output levels is preferably activated which provides the next lower heating output compared to the heating output Qzu (t), and the heating output corresponding to this heating output level is supplied to the vehicle interior and its value is stored. Alternatively, if stepless heating power control is not possible, it can also be regulated to the next higher heating power level, for example.

The setpoint temperature and / or setpoint rates of change in the temperature of the vehicle interior can be determined from a predetermined setpoint temperature curve. A target temperature curve depicting a desired heating process in a vehicle interior has, for example, a first section of increasing temperature and a second section of constant temperature, the temperature in the second section being equal to the user-defined target value to which the temperature in the vehicle interior is to be regulated. When the temperature in the vehicle interior has reached this target value, the target rate of change of the temperature for subsequent calculation cycles is zero, so that once this target value has been reached, the value of the heating power to be supplied in a calculation cycle is preferably equal to the value of the power balance variable of the previous calculation cycle.

Claims (1)

Method for operating a vehicle temperature control device (G), in which method the temperature control output (Qzu) of the vehicle temperature control device (G) as a function of the rate of change of the temperature (T) of a vehicle interior as a system area (S) to be temperature-controlled and a power balance variable (B) of the temperature-controlled system System area (S) is set, comprising the measures: a) determining a target rate of change of the temperature T _soll (t) of the system area (S) to be tempered for a calculation cycle (t), b) determining the temperature control performance (Q _zu (t) ) of the vehicle temperature control device (G) for a calculation cycle (t) on the basis of a target rate of change of the temperature (T _soll (t)) of the system area to be tempered (S) for this calculation cycle (t) and on the basis of the power budget variable (B ( t-1)) of the system area (S) for a previous calculation cycle (t-1) and determining the power balance variable (B (t-1)) of the system area (S) to be tempered for the v orange calculation cycle (t-1) based on the temperature control performance (Qzu (t-1)) of the vehicle temperature control device (G) for the previous calculation cycle and the rate of change of the temperature (T (t-1)) of the system area to be temperature controlled (S) in previous calculation cycle (t-1) according to the following relationships: $${\text{Q}}_{\text{to}}\left(\text{t}\right)=\text{K}\times {\text{T}}_{\text{should}}\left(\text{t}\right)+\text{B.}\left(\text{t}-1\right),$$

$$\text{B.}\left(\text{t}-1\right)=\left({\text{Q}}_{\text{to}}\left(\text{t}-\text{1}\right)-\text{K}\times \text{T}\left(\text{t}-\text{1}\right)\right),$$

where: K is a predetermined factor, T _soll (t) the target rate of change of the temperature of the system area (S) to be tempered for this calculation cycle (t), and B (t-1) the power budget variable of the system area (S) for the previous one Calculation cycle (t-1) is, c) operating the vehicle temperature control device (G) in the calculation cycle (t) in such a way that the temperature control performance (Qzu (t)) determined for this calculation cycle (t) is provided.

Images