DK157104B - PROCEDURE FOR OPERATING THE FREEZING DEVICE IN AN ELECTRONIC CONTROL EQUIPPED - Google Patents

Description

- 1 -

DK 157104 B

The invention relates to a method for operating the freezing device in an electronic control freezer, in particular a household freezer or household freezer.

5 Freezers of the aforementioned type are usually equipped with a quick-freeze circuit, with the aid of which the cooling unit in the apparatus is permanently switched on and the lower cut-out temperature of the controller is temporarily lowered substantially. When operated, this quick-freeze circuit engages the cooling unit 10 independently of the temperature controller's coupling state. As a result of the high temperature setting which hereby sets, heat is quickly removed from the freezing products, which is then quickly frozen down to the prescribed storage temperature. In this way, the amount of heat introduced into the freezer's utility room by the newly placed, still warm goods will be prevented from being transferred to the freezing goods already stored for a long time and heated to above the maximum permitted lower temperature. Otherwise, even a short-term additional heating could otherwise cause that, for 20 long periods of time, goods stored under unfavorable conditions are sometimes even heated above the freezing point and thus significantly affected in quality and storage capacity.

In a device known from DE Publication 16 01 906 for automatic control of the freezing time by deep-25 frost basins, a timer which determines the permanent cross of the refrigerator is equipped with a setting link which has a scale which is directly adjusted in and whose linear division corresponds to an experimentally determined curve for the apparatus in question.

30 DE DE publication publication 19 46 259 also discloses a device in which a temperature controlled auxiliary switch, which is connected in parallel with the temperature regulator and with the quick freeze switch, is built into the position of the carbon muffler.

With the help of this temperature controlled auxiliary switch, 35 temperature fluctuations are automatically compensated as they occur at

DK 157104 B

- 2 - loading fresh frozen goods or by opening the lid on the freezer for a short period of time. In this way, the detrimental influence on the freezer products from short-term temperature fluctuations must be avoided.

However, these known quick freeze switches cannot safely prevent the temperature in the utility room of the freezer from being briefly raised above the maximum permitted lower temperature when placing larger quantities of new freezer products. In such cases, users of freezers are recommended to operate the quick-freeze switch for a long time, freezing of new goods, thereby lowering the temperature of the freezer's utility room well below the normal lower cut-off point of the regulator, in order to provide some cooling capacity or cooling capacity in this way. thus preventing a temperature rise above the highest permitted temperature in the freezer. The usual quick-freeze switches thus function as a "freeze switch".

However, the cold capacity provided in this way is, to a large extent, dependent on the thermal capacity of the utility room in the appliance and on the amount of the refrigerated goods stored for a long time and their nature - the so-called "basic load" - and the lower switch-off temperature. -trip. If this ground load is small, then its cold capacity at the attainment of the temporarily lower lower set-off temperature is considerably lower than in the case of higher ground load. On the other hand, under high ground loads, in this case, in some circumstances, a substantially greater cold capacity than 50 is required for the purpose described above. Thus, at high ground load, more energy is consumed, while a corresponding cold capacity at low ground load can only be achieved by an uneconomical, even lower reduction of the lower switch-off temperature.

The object of the invention lies in the task of freezing - 3 -

DK 157104 B

preparations of the aforementioned kind of method to indicate a method of freezing, according to which, as a result of various basic loads and new loads, problems arising are reliably solved in a simple manner.

According to the present invention, this task is solved by the combination of the following process steps, which, after switching on the freezing device, proceed in sequence: 10 '1) manual data entry of mass and nature of the refrigeration unit (m ^) and constant switching of the cooling unit 2) start of the freezing process as soon as the temperature in the freezer compartment in the freezer is in the control range around the intended temperature; 3) measuring the starting temperature (θ ^) of the freezing process and recording the corresponding temperature. the first time (t), (4) measurement at another time (t2) after the elapse of a predetermined time interval of the temperature then prevailing in the freezer compartment (f 25 5) determination of a current load (mg) -p) approximate numerical value (m) from a predetermined empirical table in which this numerical value (m) is determined by means of the temperature decrease (Θ2 - Θ ^) for the 30 time interval m between the first and the second time (t2 - tj) and by means of the starting temperature (Θ-,), 6) determining the end temperature (ee) of the freezing process from another empirically determined table, in which the final temperature ( θ0)

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- 4 - is determined by the numerical value (m) and the data entered for the refrigeration products (m ^), 7) setting the final temperature read in the second table (θ0) for the freezing precursor as a new intended control value, and 8) switching off the freezing switch after reaching the new intended control value and signaling freezing readiness for the apparatus.

With the precedent of the invention of the individual process steps, the freezing circuit is switched on to ensure that, independently of the current load applied in the freezer, an optimal heat or cold capacity for new freezing products is provided.

The method according to the invention is explained in the following description by means of a simplified reproduction flow diagram and three graphical representations in the drawing. In the drawing: FIG. 1 is a flow chart showing the order of the individual process steps after reading the freezing process; FIG. 2 is a graphical representation of the temperature drop occurring when the freezer switch is switched on at various basic loads; 5 is a graphical representation for explaining individual process steps according to the flowchart.

30 In the diagram of FIG. 2, the temperature Θ in the freezer compartment in the freezer is plotted as ordinate over time t as abscissa.

Herein, the storage temperature of freezer products prescribed for long-term storage is e.g. -18 ° C denoted by 0Q. This temperature corresponds to that of the regulator in the freezer - 5 -

DK 157104 B

guide the upper switch-on point at which the override of the cooling unit is switched on. It is disconnected when the lower switching point is reached.

This diagram shows how the temperature in the interior of the apparatus decreases as the controller reacts and switches on the cooling unit upon reaching the upper switching point.

The upper flat curve is illustrated including the temperature loss in the case of a large ground load, while the substantially steeper descending, lower curve indicates the temperature loss at low ground load. From this, it is seen under the premise that the temperature Θ2 at a large ground load and the substantially lower temperature θ2 at a small ground load are obtained after the precedence of the constant time differences represented. The prevailing ground load or thermal capacity of the interior of the apparatus can be determined by these relationships by means of the temporal gradients of the temperature of the interior.

It is assumed that the freezing precursor is read out at a starting temperature Θ-j, and thus at a constant time interval at a small basic load the temperature gradient such as Δ.Μ = 82 ~ 61 t

In the case of a different ground load, the dependent, different temperature gradient is obtained by analogy. The following considerations must therefore only be taken into account in the case of a small basic load.

In the flowchart according to fig. 1 of the process steps divided by the freezing process divided into each process step, the coal aggregate is coupled to a temporary control unit.

DK 157104 B

- 6 - constant cross at the "freezing start" of the freezing process and the administration of the mass of the new load must first proceed to position 1. Then, according to position (2) in the flow chart, it is checked whether the appropriate pre-conditions are fulfilled. , ie whether the appliance temperature is less than the regulator's switching point, in this case -18 * C. A prerequisite for this is that after the last closure of the door of the apparatus, a minimum time dependent on the apparatus type has elapsed and the disturbing influences arising from the last 10 door opening have elapsed.

If the aforementioned preconditions are fulfilled, the temperature gradient, further explained above, is ascertained according to (3) and (4) for a predetermined period of time ± 2 ~ t-j = At in the freezer compartment, e.g. using a mi-15 body processor. However, it must be taken into account that this temperature drop is not only dependent on the ground load m 2, but also on the starting temperature in the interior of the apparatus, since the lowering speed also changes with the falling temperature.

20 For this reason, after the passage of time, On the basis of the magnitude of the temperature decrease measured. at any output temperature below the upper switching point, no precise termination with respect to the ground load m ^ is yet to be completed. If one does not want to depend on a fixed starting temperature, it must be further known at which starting temperature the lowering was measured.

Therefore, according to position (3) in fig. 1 further, the basic load of the temperature reduction Θ2 - θ · | is calculated during the time interval t2 - t-j and of the starting temperature Θ-].

30 This connection, which has already been described by means of FIG. 2, has been determined for the apparatus in question in a sample stand and stored as a table in the microprocessor.

With the temperature decrease θ2 - θ-j, which is conveniently measured in a fixed time interval t2 - t-j = Δΐ - 7 -

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For example, below the starting temperature in the table, a numerical value m is obtained, which approximates the actual ground load.

Of the approximate ground load m, which in this way is provided at position (5) in fig. 1, and the magnitude of the new load determined for loading 10 at the beginning of the freezing is then calculated according to position (6) in fig. 1 is the ideal freezing temperature for the particular case with regard to energy saving 6e using a function of two variables. This feature could e.g. look as follows: 15 ΘΘ = A + B »m + C» m ·] ^, where A, B and C are parameters that are determined experimentally for the individual devices and must be stored in the microprocessor. This ideal freezing temperature 0e for the special case of energy saving is then transferred to the temperature regulator program as a new intended size.

As soon as this temperature 0e has reached the time tj (Fig. 3), in the last step of the method 25, the freezing readiness for the initially set amount of new load is signaled optically and / or acoustically. In the event that the initially stated amount of the new load is too large for the actual load present and the cold capacity thus obtained with the freezing process, it may be suggested that the largest new load allowed in this case by an optical indicator.

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Claims (1)

DK 157104 B - 8 - PATEHKRAlf 1. A method of operating the freezing device in an electronic control freezer, in particular a household freezer or household freezer, characterized by the combination of the following steps, which, after switching on the freezing device, are the first: data entry of mass and nature of the refrigeration products (m ^) determined for re-loading and 10 switching of the cooling unit to a constant drive, 2. start of the freezing process as soon as the temperature in the freezer compartment is in the control area around the intended temperature. temperature, 3. measurement of the starting temperature (θ ^) for the freezing loss and registration of the associated first time (t- |), 4. measurement at another time (t £) after the loss of a predetermined time interval of the temperature prevailing in the freezer compartment (* 5. Determination of a numerical value (m) corresponding to the current ground load (mç in advance, an empirically determined table in which this figure · value (m) is determined by the temperature drop (Θ2 - θ · |) in the time interval between the first and the second time (t £ - t- | ) and by means of the starting temperature a (θ- |), 6. Determination of the final temperature (θθ) of the freezing process from another, empirically determined table, in which the final temperature (θΘ) DK 157104 B - 9 - is determined by the numerical value (m) and of the data entered for the fresh frozen foods (iSI), 7. setting the 5 final temperature (θ0) read in the second table for the freezing process as a new intended regulation value, and 8. switching off the freezing switch. following the attainment of the new intended control value and signaling of freezing readiness for the apparatus.