RU2555829C2 - Control over refrigerator - Google Patents

Abstract

FIELD: physics, control.

SUBSTANCE: proposed method comprises the steps that follow. (a) Determination of temperature (T) in refrigerator chamber. (b) Comparison of said temperature with maximum temperature (T_max). (c) Comparison of said temperature (T) with minimum temperature (T_min). (d) Switching on of compressor (22) if temperature (T) exceeds maximum temperature (T_max). (e) Switching off of said compressor if temperature (T) drops below minimum temperature (T_min). (f) Alternate switching on of compressor for time (t_ern) and switching off for time (t_aus) when temperature (T) is lower than maximum temperature (T_max) and higher than minimum temperature (T_min). (g) Variation of switch-off temperature (t_aus) depending on temperature (T). Refrigerator comprises at least one refrigerator chamber, refrigerating circuit including the compressor, control device and temperature sensor to define temperature in refrigerator chamber.

EFFECT: higher efficiency of operation.

12 cl, 3 dwg

Description

Technical field

This invention relates to a method for controlling a refrigeration apparatus. The refrigeration apparatus includes at least one refrigerating chamber, which is closed by at least one door. In addition, the refrigeration apparatus includes a refrigeration circuit in which there is a compressor and a control device for turning the compressor on or off.

State of the art

Such a method of controlling a refrigeration apparatus is known from patent document DE 10 2009 001 678 A1. In the known method, the temperature that takes place in the refrigerator is first determined and compared with the maximum temperature and the minimum temperature. The compressor is turned on if the temperature exceeds the maximum temperature, and turned off if the temperature drops below the minimum temperature. When the temperature is below the maximum temperature and above the minimum temperature, that is, in the range between the maximum temperature and the minimum temperature, then the compressor is alternately turned on for a certain on time and turned off for a certain off time. In the known method, the on time and the off time are predetermined, that is, the compressor is turned on and off with time control. This embodiment implies the disadvantage that it is necessary to determine in advance the on-time and the off-time for the refrigerator. This can lead to non-uniform cooling cycles - in particular, in cases where the prevailing conditions are significantly different from the conditions that are provided for the refrigeration unit. As a result of this, the temperature in the refrigerator often exceeds the maximum temperature or accordingly falls below the minimum temperature, as a result of which the efficiency of the refrigerator decreases. In addition, due to the pre-setting of the on-time and the off time, the disadvantage is the need to determine the on-time and the off time in advance through lengthy series of tests.

Disclosure of invention

The objective of the invention is to avoid the disadvantages of the method known from the prior art, and thereby improve the known method of controlling the refrigeration apparatus.

To solve this problem, a method according to paragraph 1, as well as a device according to paragraph 10.

Preferred embodiments of the method according to the invention are described in paragraphs 2-9. Preferred embodiments of the device according to the invention are described in paragraphs 11 and 12.

The method for controlling the refrigeration apparatus according to the invention is characterized in particular in that the control of the refrigeration apparatus is dynamically controlled by adjusting the shutdown time depending on the temperature. This means that it is possible to abandon a long series of tests to establish the regulation characteristics.

Furthermore, the method according to the invention offers the advantage that the control characteristics are optimized, in particular, for different ambient temperatures and different temperatures in the refrigerator. In addition, through the method according to the invention, the efficiency of the operating device is optimized.

The difference between the maximum temperature and the minimum temperature is preferably from 0.1 ° to 10 °, preferably from 0.2 ° to 2 °, even more preferably from 0.5 ° to 1 °.

In a preferred embodiment of the method according to the invention, the adjustment of the shutdown time as a function of temperature is carried out only under constant operating conditions. This embodiment provides the advantage that the regulation characteristics of the refrigeration apparatus do not adapt to short-term changing conditions, as a result of which the regulation characteristics are optimized in the presence of these constant conditions.

The method according to the invention is preferably characterized in that the presence of constant conditions includes the presence for a certain period of time of the closed state of the door and / or approximately constant ambient temperature and / or the occurrence of the defrost phase. This embodiment offers the advantage that interfering external influences do not affect the adaptation process of the adjustment of the refrigeration apparatus, thereby improving the regulation characteristic for conditions that have remained unchanged for a long time. Such possible external influences are, for example, a significant change in the ambient temperature or a short-term equalization of the temperature of the outdoor air and the internal temperature in the refrigerator, which occurs when the door is opened. The defrosting phase can also affect the temperature inside the refrigerator so that it becomes impossible to adapt the control depending on temperature. For this reason, it is preferable not to undertake temperature control during the defrost phase.

Alternatively, it is possible to determine the presence of constant conditions based on the control characteristic of the control device. So, in particular, the cyclical returns of the regulation characteristic for some time indicate the presence of more constant conditions. It does not matter if the control characteristic is optimized with respect to the existing environmental conditions or not. If the regulation characteristic is constant and / or cyclically repeated over a time interval, it can be concluded that there are constant conditions.

Furthermore, the method according to the invention is preferably characterized in that the time interval is from 10 minutes to 12 hours, preferably from 30 minutes to 6 hours, even more preferably from 1 hour to 5 hours. This embodiment offers the advantage that the possibility of acceptance is excluded temperature changes due to short-term reasons, as a basis for adapting the adjustment of the refrigeration unit. So, for example, when filling the refrigerator with a relatively large amount of relatively warm liquid, say, uncooled drinks, the temperature inside the refrigerator increases for a certain period. If the control characteristic of the refrigeration apparatus was adapted to these conditions, then the efficiency of the refrigeration apparatus would be less suitable for the case of constantly operating conditions. In accordance with this, the adaptation of the regulatory characteristics of the refrigeration apparatus is carried out only in the presence of constantly operating conditions.

In a preferred embodiment of the method according to the invention, the shutdown time is adjusted by reducing the shutdown time when the maximum temperature is exceeded. In addition, the method preferably differs in that the adjustment of the shutdown time is carried out by increasing the shutdown time if the temperature drops below the minimum.

An advantage offered by this embodiment is that the temperature in the interior of the refrigeration apparatus remains, as far as possible, within the temperature range limited by the minimum temperature and the maximum temperature. The result is increased energy efficiency. In addition, the embodiment offers the advantage that the shutdown time is automatically selected such that the temperature in the interior of the refrigerator under constantly unchanged conditions remains within the temperature range for as long as possible. In addition, it is possible to abandon the preliminary determination of the duration of the shutdown for a given refrigeration unit, which is carried out with great time costs.

As an alternative to the embodiment described above, instead of decreasing the off time, it would be possible to increase the on time. This would also lead to an improved control performance of the refrigeration apparatus. However, this embodiment has the disadvantage that the optimal on-time, or the duration of the compressor, which is determined for a given refrigeration circuit in advance, is reset. In this regard, to optimize the adjustment of the refrigeration unit, a change in the off time should be preferred to a change in the on time.

In a preferred embodiment, the method according to the invention is characterized in that after decreasing and / or increasing the shutdown time, a marker is placed to prevent the reduction and / or increase of the shutdown time again, and after a certain blocking period, the marker is removed to allow a decrease and / or an increase in time shutdowns. The blocking time is preferably determined by the number of compressor operating periods. The duration of the compressor working period is obtained from the sum of the time it was turned off and the time it was turned on.

An advantage of this embodiment is that regulation is better adapted to long-term environmental changes.

The blocking time is preferably at least two working periods. Further, the blocking time is preferably from 2 to 20 times the length of the working period. In addition, preferably a blocking time of 2 to 10 working periods.

In a preferred embodiment, the method is characterized in that the turn-on time is from 30 seconds to 30 minutes, preferably from 1 minute to 10 minutes, even more preferably about 4 minutes. In addition, the shutdown time is preferably from 1 minute to 60 minutes, preferably from 2 minutes to 20 minutes, even more preferably about 8 minutes.

It is preferable to decrease the shutdown time by a constant value when the maximum temperature is exceeded and increase it by a constant value when the temperature drops below the minimum. A constant value is from 5 seconds to 5 minutes, preferably from 10 seconds to 2 minutes, even more preferably about 0.5 minutes.

An apparatus according to the invention for carrying out the method according to the invention comprises at least one refrigerating chamber, which is closed by at least one door, a refrigerating circuit comprising a compressor; a control device for turning the compressor on or off, and a temperature sensor for detecting the temperature in the refrigerator.

The apparatus according to the invention takes advantage of the method according to the invention. The apparatus according to the invention preferably includes a device for determining the presence of constant operating conditions.

In addition, the device preferably includes an external temperature sensor configured to measure the ambient temperature. In a preferred embodiment, said device includes a door sensor configured to detect an open position of a door.

In addition, the specified device is preferably configured to determine the onset of the defrost phase.

Brief Description of the Drawings

Details and further advantages of the method according to the invention and the device according to the invention follow from the preferred embodiment described below. In the drawings, which only schematically illustrate an embodiment, are presented individually:

figure 1: schematic view of a refrigeration apparatus according to the invention;

figure 2: a diagram that represents the course of the change in temperature measured in the refrigerating chamber of the refrigeration apparatus, and the progress of the change in compressor productivity depending on time for a conventional refrigeration apparatus;

figure 3: a diagram that represents the course of the temperature change measured in the refrigerator chamber of the refrigeration apparatus, and the progress of the change in compressor capacity, depending on time, for the refrigeration apparatus according to the invention.

The implementation of the invention

Figure 1 shows a schematic view of a refrigeration apparatus 10. The refrigeration apparatus 10 includes a refrigeration chamber 14, which is closed by a door 12, a refrigeration circuit 20 and a control device 30. The refrigeration circuit 20 includes, in particular, a compressor 22. The temperature sensor 32 of the control device 30 is located in the interior of the refrigeration chamber 14 and measures the air temperature T in the refrigeration chamber 14.

In a preferred embodiment, the control device 30 of the refrigerator 10 has a door sensor 34 that detects whether the door 12 of the refrigerator 10 is open or closed. Accordingly, the sensor of the door 34 is able to detect if it is blocking the air inside the refrigerator 14. 10 with air outside the refrigerator 10. Thus, a closed door 12 helps maintain constant temperatures inside the refrigerator 14.

An external temperature sensor 36 may be provided in the control device 30 of the refrigeration apparatus 10. It is advisable to position the external temperature sensor 36 on the outside of the refrigeration apparatus 10. The external temperature sensor 36 of the control device 30 is preferably positioned so that possible heat transfer from the evaporator of the refrigeration circuit 20 does not affect the measurement outdoor temperature.

Figure 2 shows a diagram that depicts the course of the temperature and the performance of the compressor 22 of the refrigeration apparatus 10, and the regulation characteristic is not yet optimized for the prevailing environmental conditions. In the lower region of the diagram, the course of the temperature T inside the refrigerating chamber 14 of the refrigerating apparatus 10 is reflected. The temperature T has strong fluctuations due to the irregular control characteristic.

If the temperature T is within the range from Tmin to Tmax, then the compressor 22 of the refrigeration apparatus 10 according to the invention is alternately turned on for a time equal to the turn-on time tern and turned off for a time equal to the turn-off time t _aus .

If the temperature T exceeds the temperature Tmax, then a marker is installed, if it is not already set, and the shutdown time t _aus for future cycles is reduced. If the marker is already set, the shutdown time t _aus remains unchanged. After passing a certain predetermined number of cycles, the markers are deleted again.

If the temperature T drops below the minimum temperature Tmin, then the compressor 22 is turned on, and the shutdown time t _aus is increased by the same constant value if the marker is not already set, and then such a marker is set. The marker is again deleted after passing a predetermined number of cycles.

If the temperature T decreases from a level exceeding the maximum temperature Tmax, so that the temperature T is again between Tmin and Tmax, then the compressor 22 is first turned off for a period equal to the shutdown time t _aus . If the temperature T rises from a level below the minimum temperature Tmin to a temperature that is within the range determined by the minimum temperature Tmin and the maximum temperature Tmax, then the compressor 22 is turned off for a shutdown time t _aus .

As can be seen, in particular, from the graph transmitting the compressor performance, for this embodiment, the presence of constant conditions is expressed in the regularly repeated behavior of the control characteristic (three short peaks of performance and then one long).

Figure 3 conveys an optimized control characteristic of the refrigeration apparatus 10 according to the invention. With an optimized control characteristic, the values of the on time tern and the time t _aus trip remain unchanged over time. The temperature T also remains relatively constant and varies within the interval between the minimum temperature Tmin and the maximum temperature Tmax.

According to the invention, the control characteristic shown in FIG. 3 is independently set in such a way that the temperature does not go beyond a predetermined interval and the duration t _aus of the shutdown phases, as well as the duration t _{ein of the} shutdown phases, remains constant for quite some time.

As the diagram shown in FIG. 2 explains, the compressor 22 is turned on three times in succession three times at the turn-on time t _ein and off for the shutdown time t _aus . This is followed by a longer start-up of the compressor 22, the duration of which exceeds the turn-on time t _ein . This is due to the fact that the temperature T has risen above the maximum temperature Tmax. As can be seen further in FIG. 2, after a longer shutdown phase, the described adjustment pattern follows again. Therefore, this regularly repeated and returning characteristic of the adjustment indicates the presence of constant conditions. The diagram depicted in FIG. 3 also indicates a repeating adjustment characteristic of the control device 30. Therefore, it also follows from the diagram shown in FIG. 3 that there are constant conditions. Accordingly, the shutdown time t _aus is adjusted to improve the control characteristic of the control device 30.

The method according to the invention for a refrigeration apparatus allows optimizing the efficiency of the refrigeration apparatus. In addition, the method according to the invention provides optimal controller settings, regardless of the ambient temperature and the temperature in the chamber. In addition, thanks to the method according to the invention, the costs of testing and, accordingly, development are reduced. In addition, the method according to the invention is implemented at low cost, based on software.

Designations

10 refrigeration unit

12 door

14 cold store

20 refrigeration circuit

22 compressor

30 control device

32 temperature sensor

34 door sensor

36 external temperature sensor

T temperature

Tmax maximum temperature

Tmin minimum temperature

t _{ein on} time

t _aus off time.

Claims (12)

1. A method for controlling a refrigerating apparatus (10) comprising at least one refrigerating chamber (14) which is closed by at least one door (12), a refrigerating circuit (20) comprising a compressor (22), and a control device (30) designed to enable or disable the compressor (22), characterized by the following technological operations:
a) determination of temperature (T) in the refrigerator (14);
b) comparing temperature (T) with maximum temperature (Tmax);
c) comparing temperature (T) with minimum temperature (Tmin);
d) turning on the compressor (22) if the temperature (T) exceeds the maximum temperature (Tmax);
e) turning off the compressor (22) if the temperature (T) drops below the minimum temperature (Tmin);
f) alternately turning on the compressor (22) at the time (t _ein ) on and off the compressor (22) at the time (t _aus ) off when the temperature (T) is below the maximum temperature (Tmax) and above the minimum temperature (Tmin);
g) change of time (t _aus ) of shutdown depending on temperature (T). 2. The method according to p. 1, characterized in that the change in time (t _aus ) shutdown, depending on the temperature, is carried out only under constant operating conditions. 3. The method according to p. 2, characterized in that the presence of constant conditions includes a state where for a certain time interval the door (12) remains closed and / or the ambient temperature remains approximately constant and / or the defrost phase does not occur. 4. The method according to p. 3, characterized in that the time interval is from 10 minutes to 12 hours, preferably from 30 minutes to 6 hours, particularly preferably from 1 hour to 3 hours. 5. The method according to claim 1, characterized in that the change in time (t _aus ) shutdown is carried out by reducing the time (t _aus ) shutdown when exceeding the maximum temperature (Tmax). 6. The method according to claim 1, characterized in that the change in time (t _aus ) shutdown is carried out by increasing the time (t _aus ) shutdown when the temperature drops below the minimum temperature (Tmin). 7. The method according to claim 5 or 6, characterized in that after decreasing and / or increasing the turn-off time (t _aus ), a marker is placed to prevent a repeated decrease and / or increase of the turn-off time, and after a certain blocking period, the marker is removed to allow decrease and / or increase shutdown time. 8. The method according to claim 1, characterized in that the turn-on time (t _ein ) is from 30 seconds to 30 minutes, preferably from 1 minute to 10 minutes, even more preferably about 4 minutes. 9. The method according to claim 1, characterized in that the shutdown time (t _aus ) is from 1 minute to 60 minutes, preferably from 2 minutes to 20 minutes, even more preferably about 8 minutes. 10. Refrigeration apparatus for implementing the method according to one of paragraphs. 1-9, containing at least one refrigerating chamber (14), which is closed by at least one door (12); a refrigeration circuit (20) comprising a compressor (22); a control device (30) configured to control the refrigeration apparatus according to one of claims 1 to 9, and a temperature sensor (32) for detecting the temperature (T) in the refrigerating chamber (14). 11. The refrigerator according to claim 10, characterized in that it comprises a device for determining the presence of constant operating conditions. 12. The refrigeration apparatus according to claim 11, characterized in that said device includes an external temperature sensor (36) configured to measure the ambient temperature and / or a door sensor (34) configured to detect an open position of the door ( 12), and / or the specified device is configured to determine the onset of the defrost phase.

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