JPH10339555A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable dew prevention with less energy consumption by arranging an outside air humidity sensor in the vicinity of the door hinge cover on the top of a casing, or a substrate storage, and controlling the current application to the dew condensation preventive heater provided at the partition part of the door. SOLUTION: A casing surface temperature sensor 9 or an outside air humidity sensor 10 is arranged in the vicinity or the like of the hinge cover part 8 of the door at the top of the casing or the substrate storage of a refrigerator where there is little influence of the temperature by the outflow of the chill caused by the opening or closing of a door or the heat radiation caused by the fan of a condenser, and dew deposition is hard to occur. Then, the detection signals of the casing surface temperature sensor 9 and the outside air humidity sensor 10 are inputted into a controller 13, and in the controller 13, it becomes possible to perform dew prevention with less energy consumption by computing the quantity of current application to each dew preventive heater 7a-7c, based on these signals, and inputting the required power to the dew preventive heaters 7a-7c into on-off elements 11a-11c by the control signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing dew condensation in a refrigerator.

[0002]

2. Description of the Related Art As a technique for preventing dew condensation in a conventional refrigerator, there is one disclosed in Japanese Patent Application Laid-Open No. 8-166184.

Hereinafter, an example of the above-mentioned conventional refrigerator will be described with reference to FIGS. 15 and 16. FIG. 14 is a schematic configuration diagram of a conventional refrigerator, and FIG. 15 is a flowchart for explaining the operation of the refrigerator.

[0004] Since the inside of the refrigerator is cooled, dew condensation tends to occur particularly near the gasket on the refrigerator main body side where the door contacts. On the other hand, in this conventional example, a part of the pipe 26 on the high pressure (high temperature) side in the refrigeration cycle is routed around the door contact surface on the side of the refrigerator body 25, and the periphery of the door contact surface is heated during operation of the refrigeration cycle. To prevent dew. At this time, the surrounding environment, in particular, the temperature and humidity are grasped, and the surface temperature at which dew condensation easily occurs is measured by temperature sensors 27 to 31 provided at several places, and as shown in FIG. The dew condensation temperature (dew point + α) is calculated from the temperature and the humidity (dew point + α) (step 1). When the door contact surface temperature and the dew condensation prevention temperature are not required (step 2 is branched to the Y side), the refrigeration cycle is performed. The refrigerant is switched by the solenoid valve 34 to the bypass pipe 33 to the side surface of the outer box other than the vicinity of the door contact surface with the high temperature side pipe (step 3), and when the dew prevention is necessary, the refrigerant is transferred to the pipe 26. It is made to flow (step 4).

[0005]

Conventionally, the surrounding environment,
In particular, while grasping the temperature and humidity, the dew prevention means uses a solenoid valve by comparing the surface temperature of the dew prevention part with the dew condensation prevention temperature from room temperature and humidity. Switching, or the main purpose is to prevent the internal temperature from rising when the door is opened or closed (not shown), or the dew prevention control is performed only by the output of the humidity sensor provided in the condensation part (not shown). However, in the first method, it is necessary to simultaneously switch the refrigerant in the pipe that bypasses almost the entire surface around the door contact surface in accordance with the lowest surface temperature, The second method is to minimize the energy consumption when opening and closing the door, and the third method is to reduce the condensation With a humidity sensor Ri, heater, or greater cost increase in the number of humidity sensors, the accuracy due to contamination or the like of the humidity sensor, or leaving anxiety reliable surface or the like, either method had some drawbacks.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a refrigerator that requires less energy to perform dew prevention.

[0007]

According to a first aspect of the present invention, there is provided an external air humidity sensor and a housing disposed near a door hinge cover or a board storage at an upper portion of the housing. There is provided a control means for controlling energization to the dew condensation prevention heater provided at the door and the partition of the door in accordance with the output of the surface temperature sensor.

According to a second aspect of the present invention, in the refrigerator according to the first aspect, the housing surface temperature sensor is attached to a portion other than the surface of the refrigerator body around the gasket where the door comes into contact, where dew condensation is likely to occur.

According to a third aspect of the present invention, a high temperature side pipe surface temperature sensor of a refrigeration cycle is used in place of the housing surface temperature sensor in the refrigerator of the first aspect.

[0010] According to a fourth aspect of the present invention, a low temperature side piping surface temperature sensor of a refrigeration cycle is used in place of the housing surface temperature sensor in the refrigerator of the first aspect.

According to a fifth aspect of the present invention, an operation rate calculating means for calculating an operation rate of a compressor of a refrigeration cycle is used instead of the housing surface temperature sensor in the refrigerator of the first aspect.

As a result, it is possible to provide a refrigerator that requires less energy to perform dew prevention.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to a first aspect of the present invention is directed to an outside air humidity sensor, a housing surface temperature sensor, and a door and a door. A dew condensation prevention heater provided in a partition portion, and control means for controlling energization to the dew condensation prevention heater in accordance with outputs of the housing surface temperature sensor and the outside air humidity sensor. Effect of temperature and humidity changes due to the outflow of cold air due to opening and closing, heat radiation by the condenser fan around the machine room, less influence of dust, and the door hinge cover part on the upper part of the refrigerator housing that is hardly dewed, or
By arranging in the vicinity of the substrate storage unit, the humidity of the outside air is accurately detected, and the heating of each of the condensation prevention heaters is controlled by each of the condensation prevention heater currents calculated in advance from the housing surface temperature and the outside air humidity. This makes it possible to perform dew prevention with less energy consumption. The humidity sensor is less susceptible to heat radiation, cooling, dew condensation, and dust generated by the refrigerator itself, thereby preventing sensitivity deterioration or malfunction of the sensor.

According to a second aspect of the present invention, in the first aspect of the present invention, the housing surface temperature sensor is attached to a surface of the housing other than the surface of the refrigerator body around the gasket where the door comes into contact, where condensation is likely to occur. It is hardly affected by the change of the outside air temperature in a relatively short cycle such as the influence of the cool air in the refrigerator, the cool air of opening and closing the door, and the heat radiation of the machine room. The amount of electricity to be supplied to the dew condensation prevention heater can be accurately calculated from the outside air humidity, and the amount of extra electricity to be supplied in consideration of variations can be reduced, thereby reducing energy consumption.

According to a third aspect of the present invention, there is provided an outside air humidity sensor disposed in the vicinity of a door hinge cover portion or a substrate storage portion on an upper portion of a housing, a piping surface temperature sensor on a high pressure side of a refrigeration cycle, a door and a door. And a control means for controlling energization to the dew condensation prevention heater in accordance with the output of the piping surface temperature sensor on the high pressure side of the refrigeration cycle and the outside air humidity sensor. However, even if a piping surface temperature sensor on the high-pressure side of the refrigeration cycle is used instead of the housing surface temperature sensor in the first aspect of the present invention, the outside air temperature and the refrigeration cycle high-side temperature are correlated. The same dew condensation prevention heater as that of the invention described in the first aspect can be controlled, and the same operation can be obtained.

According to a fourth aspect of the present invention, there is provided an outside air humidity sensor disposed in the vicinity of a door hinge cover portion or a substrate storage portion in an upper portion of a housing, a piping surface temperature sensor on a low pressure side of a refrigeration cycle, a door and a door. And a control means for controlling energization of the dew condensation prevention heater in accordance with the output of the low pressure side pipe surface temperature sensor and the outside air humidity sensor of the refrigeration cycle. Even if a piping surface temperature sensor on the low pressure side of the refrigeration cycle is used in place of the housing surface temperature sensor in the first aspect of the present invention, the outside air temperature and the refrigeration cycle low pressure side temperature have a correlation. The same dew condensation prevention heater as that of the invention described in the first aspect can be controlled, and the same operation can be obtained.

According to a fifth aspect of the present invention, there is provided an outside air humidity sensor disposed near a door hinge cover portion or a substrate storage portion at an upper portion of a housing, and an operation rate calculating means for calculating an operation rate of a compressor of a refrigeration cycle. And a control unit for controlling energization to the dew condensation prevention heater according to the output of the operation rate calculation unit and the outside air humidity sensor, Claim 1
Instead of the housing surface temperature sensor in the invention described in the above,
Even when using the operation rate calculation means for calculating the operation rate of the compressor,
Since there is a correlation between the outside air temperature and the operating rate of the compressor, it is possible to control the dew condensation prevention heater equivalent to the first aspect of the invention, and to obtain the same operation.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the refrigerator according to the present invention will be described below with reference to the drawings. 1, 2, 3, 4, 5, and 6
FIG. 1 is a diagram showing an embodiment of the present invention. It should be noted that this embodiment corresponds to the embodiments 1, 2, 3, 4, 5 according to each claim.
Will be described in order.

(Embodiment 1) A description will be given with reference to FIGS. In FIG. 1, 1 is a housing, 2 is a door, and a housing 1
Is roughly divided into four compartments, and from the top, a refrigerator compartment 3 (average temperature is about + 3 ° C.), a switching compartment 4 (when switched to a freezing compartment; about -20 ° C., when switched to a refrigerator compartment; about) + 3 ° C),
Freezer compartment 5 (approx. -20 ° C), Vegetable compartment 6 (approx.
° C). Since the inside of the refrigerator is cooled, dew condensation tends to occur on the horizontal partition plate 1a, the wall surface, or the door 2 of the housing 1 adjacent to the freezing compartment 5 where the temperature is particularly low.

In this embodiment, a dew-proof heater 7a is provided on the horizontal partition plate where dew condensation is likely to occur as a heating means for performing dew-proof.
To 7c. Hereinafter, the dew-proof heaters 7a to 7c
Is referred to as the dew-proof heater 7. Door 2 at the top of case 1
A housing surface temperature sensor 9 and an outside air humidity sensor 10 are installed in a hinge cover 8 for supporting the housing (FIG. 2). In this way, in the figure, the housing surface temperature sensor 9 and the outside air humidity sensor 10 are provided one by one, but a plurality of housing surface temperature sensors 9 and outside air humidity sensors 10 may be provided by being incorporated in the lower part of the housing 1 or the door portion.

FIG. 4 shows a control system of the dew-proof heater 7. Detection signals from the housing surface temperature sensor 9 and the outside air humidity sensor 10 are input to the control unit 13 as control means, and are turned on and off by a control signal from the control unit 13 that controls the amount of electricity to each dew-proof heater 7 based on the detection signals. Elements 11a to 11c
, The required electric power can be input to the dew-proof heater 7. Hereinafter, the on / off elements 11 are referred to as the on / off elements 11a to 11c. FIG. 5 shows a flowchart for controlling the amount of current supplied to each of the dew-proof heaters 7 in the control unit 13. When a certain time and T _0, for every T ₀ (ste
(p5 is branched to Y side) The housing surface temperature and the outside air humidity, which are the environmental humidity representing the outside air temperature of the refrigerator, were measured (step
6) Each type of dew-prevention that does not cause dew condensation on the horizontal partition plate according to the surface temperature of the housing and the outside air humidity, which is calculated in advance based on the structure of the horizontal partition plate of the refrigerator, the upper and lower refrigerator temperature setting values of the horizontal partition plate The energization amount of each dew-proof heater 7 is calculated by a formula for calculating the energization amount of the heater 7 (step 7), and the energization amount of each dew-proof heater 7 is changed (step 8).

Next, the operation of this embodiment will be described. The influence of temperature and humidity changes due to the outflow of cool air due to opening and closing of the door, heat radiation by the condenser fan around the machine room, and the effect of dust are small.
In addition, by arranging the housing surface temperature sensor 9 and the outside air humidity sensor 10 near the hinge cover 8 of the door 2 at the upper part of the housing 1 of the refrigerator 1 where the dew is hardly formed, or near the substrate storage unit, the outside air Is detected with high accuracy, and a control signal to each of the dew condensation preventing heaters 7 calculated in advance by the control unit 13 from the housing surface temperature and the outside air humidity is supplied to each of the dew condensation preventing heaters, thereby reducing energy consumption. It is possible to perform dew prevention.

As described above, according to this embodiment, the outside air humidity sensor is hardly affected by the high temperature condensation heat, the low temperature cold air, the condensation on the outer surface of the housing, and the dust carried by the condenser fan. Is prevented from deteriorating in sensitivity or malfunctioning.

(Embodiment 2) A description will be given with reference to FIG. The surface temperature distribution of the refrigerator housing is such that when the outside air temperature is 30 ° C., the surface of the refrigerator housing around the gasket where the door comes into contact is easily condensed,
For example, at point B in FIG. 3, the surface is approximately 6 ° C. lower than the surface of the other refrigerator housing, for example, point A in FIG. The calculated value of the amount of electricity supplied to the dew condensation prevention heater from the surface temperature of the housing and the outside air humidity as the value to be reduced is about 1 W less, which is the temperature at which dew condensation occurs. Therefore, if the temperature is outside the temperature of the housing surface other than the surface of the refrigerator housing where dew condensation is likely to occur and the humidity of the outside air, the amount of electricity to be supplied to the dew condensation prevention heater can be calculated with high accuracy, thereby preventing erroneous dew condensation. In addition, the amount of energization is set higher in consideration of the variation, and the energy consumption does not increase accordingly.

As described above, according to the present embodiment, since the housing surface temperature sensor is not installed on the housing surface portion which is easy to dew and is far from the outside air temperature, the sensor has a close value substantially linked to the outside air temperature. As a result, a highly accurate dew point temperature can be calculated, and the amount of power to be supplied to each of the dew condensation preventing heaters is calculated on the basis of the calculated temperature.

(Embodiment 3) A description will be given with reference to FIGS. 7, 8, and 9. FIG. In FIG. 7, if the pipe surface temperature on the high pressure side of the refrigeration cycle, for example, the condenser outlet pipe 17c is detected by the pipe surface temperature sensor 9a on the high pressure side of the refrigeration cycle, and control is performed as shown in the flowchart of FIG. Since there is a correlation between the outside air temperature and the refrigeration cycle high-pressure side pipe temperature, the same operation as in claim 1 can be obtained.

(Embodiment 4) A description will be given with reference to FIGS. 10, 11, and 12. FIG. In FIG. 8, the pipe surface temperature on the low pressure side of the refrigeration cycle, for example, the suction pipe 17d is detected by the pipe surface temperature sensor 9b on the low pressure side of the refrigeration cycle,
If the control is performed as shown in the flowchart of FIG. 12, since the outside air temperature and the refrigeration cycle low-pressure side pipe temperature have a correlation, the same operation as the first aspect can be obtained.

(Embodiment 5) A description will be given with reference to FIGS. In FIG. 13, means for calculating the operation rate of the compressor of the refrigeration cycle is provided in the control unit 13, a control signal for the compressor motor 16 is sent from the switching power supply 15, and the operation rate is calculated by the operation rate calculation means 14. However, if the heater energization amount is determined according to the flowchart shown in FIG. 14, the same operation as the first aspect can be obtained.

[0029]

As described above, according to the first aspect of the present invention, the influence of temperature and humidity changes due to the outflow of cool air due to the opening and closing of the door, the heat radiation by the condenser fan around the machine room, and the influence of dust are small. In addition, by arranging a humidity sensor in the vicinity of the door hinge cover portion of the refrigerator housing or the substrate housing portion where dew is hard to occur, the humidity of the outside air is accurately detected, and the temperature of the housing surface and the outside air are detected. By controlling the heating of each dew condensation prevention heater with each of the dew condensation prevention heater energization amounts calculated in advance from the humidity, dew prevention can be performed with less energy consumption. In addition, the humidity sensor is hardly affected by heat radiation, cooling, condensation, and dust emitted by the refrigerator itself,
Sensor sensitivity deterioration or malfunction can be prevented.

According to the second aspect of the present invention, since the housing surface temperature sensor is attached to a portion other than the surface of the refrigerator body around the gasket where the door is in contact, the surface of the refrigerator body is easily exposed to dew. When the temperature is based on the surface temperature of the housing and the humidity of the outside air, the amount of electricity to be supplied to the dew condensation prevention heater can be calculated with high accuracy, thereby preventing erroneous dew condensation. In addition, the amount of energization is set higher in consideration of the variation, and the energy consumption does not increase accordingly.

According to the third aspect of the present invention, even if a piping surface temperature sensor on the high pressure side of the refrigeration cycle is used in place of the housing surface temperature sensor, there is a correlation between the outside air temperature and the refrigeration cycle high pressure side temperature. Accordingly, the same dew condensation prevention heater as that of the first aspect can be controlled, and the same effect can be obtained.

According to the fourth aspect of the present invention, even if a piping surface temperature sensor on the low pressure side of the refrigeration cycle is used instead of the housing surface temperature sensor, there is a correlation between the outside air temperature and the refrigeration cycle low pressure side temperature. Accordingly, the same dew condensation prevention heater as that of the first aspect can be controlled, and the same effect can be obtained.

According to the fifth aspect of the present invention, the outside air temperature and the operating rate are correlated even when the operating rate calculating means for calculating the operating rate of the compressor of the refrigeration cycle is used instead of the surface temperature sensor. Accordingly, the same dew condensation prevention heater as that of the first aspect can be controlled, and the same effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing a state in which a door is opened in a first embodiment of a refrigerator according to the present invention.

FIG. 2 shows a housing surface temperature sensor according to the first embodiment;
A perspective view showing an example of installation of a humidity sensor and an energization means.

FIG. 3 is a schematic enlarged view around a gasket where a door comes into contact in the first embodiment.

FIG. 4 is a circuit diagram showing a control system of an energizing means in the first embodiment.

FIG. 5 is a flowchart illustrating control of an energizing unit in the first embodiment.

FIG. 6 is a characteristic diagram showing a housing surface temperature characteristic of a dew-proof heater energizing amount for explaining a dew point temperature and a dew-proof heater energizing amount difference due to a housing surface temperature difference at an outside air humidity of 85% in the first embodiment.

FIG. 7 is a schematic perspective view showing an installation example of a refrigeration cycle high-pressure pipe surface temperature sensor in a third embodiment.

FIG. 8 is a circuit diagram showing a control system of an energizing means in the third embodiment.

FIG. 9 is a flowchart illustrating control of an energizing unit in the third embodiment.

FIG. 10 is a schematic perspective view showing an installation example of a refrigeration cycle low-pressure pipe surface temperature sensor in a fourth embodiment.

FIG. 11 is a circuit diagram showing a control system of an energizing means in the fourth embodiment.

FIG. 12 is a flowchart illustrating control of a current supply unit in the fourth embodiment.

FIG. 13 is a circuit diagram showing a control system of an energizing means in a fifth embodiment.

FIG. 14 is a flowchart illustrating control of an energizing unit in the fifth embodiment.

FIG. 15 is a schematic perspective view showing a dew-proof structure in a conventional refrigerator.

FIG. 16 is a flowchart illustrating dew prevention control in the above-described conventional example.

[Explanation of symbols]

 Reference Signs List 1 housing 1a horizontal partition plate 2 door 5 freezer compartment 7, 7a, 7b, 7c dew-proof heater 8 hinge cover 9, 27, 28, 29, 30 housing surface temperature sensor 9a piping surface temperature sensor on high pressure side of refrigeration cycle 9b Low temperature side piping surface temperature sensor of refrigeration cycle 10 Outside air humidity sensor 11, 11a, 11b, 11c ON / OFF element 25 Refrigerator body 26 Door contact surface pipe 33 Outer box side bypass pipe 34 Solenoid valve

Claims (5)

[Claims] An outside air humidity sensor disposed in the vicinity of a door hinge cover portion or a substrate storage portion in an upper portion of the housing, a housing surface temperature sensor, a dew condensation preventing heater provided in a partition between the door and the door, A refrigerator comprising: control means for controlling energization of the dew condensation prevention heater in accordance with outputs of the housing surface temperature sensor and the outside air humidity sensor. 2. The refrigerator according to claim 1, wherein the housing surface temperature sensor is attached to a portion other than the surface of the refrigerator body where dew condensation is likely to occur around a gasket contacting the door. 3. An external air humidity sensor disposed near a door hinge cover portion or a substrate storage portion at an upper part of a housing, a piping surface temperature sensor on a high pressure side of a refrigeration cycle, and a door-to-door partition portion. A refrigerator comprising: a dew condensation prevention heater; and control means for controlling energization of the dew condensation prevention heater in accordance with an output of a piping surface temperature sensor on a high pressure side of the refrigeration cycle and an outside air humidity sensor. 4. An external air humidity sensor disposed near a door hinge cover or a substrate storage section at an upper part of a housing, a pipe surface temperature sensor on a low pressure side of a refrigeration cycle, and a door-to-door partition. A refrigerator comprising: a dew condensation prevention heater; and control means for controlling energization to the dew condensation prevention heater in accordance with an output of a pipe surface temperature sensor on a low pressure side of the refrigeration cycle and an output of the outside air humidity sensor. 5. An outside air humidity sensor disposed near a door hinge cover portion or a substrate storage portion at an upper part of a housing, and an operation rate calculation means for calculating an operation rate of a compressor of a refrigeration cycle;
A refrigerator comprising: a dew condensation preventing heater provided at a door and a partition between the doors; and a control unit that controls energization of the dew condensation preventing heater in accordance with an output of the operation rate calculation unit and the outside air humidity sensor. .