RU186275U1 - Household refrigerator - Google Patents

Abstract

The utility model relates to domestic refrigerators (without a freezer) designed for food storage and operated year-round in unheated rooms. The objective of the utility model is to create a simple, easy-to-use, inexpensive refrigerator with reduced annual energy consumption. The essence of the device is that the refrigerator is equipped with an electric heater, and the thermostat is made in two sections, the first section is a standard 2-pin thermo-dependent switch located inside the refrigerator, and the second section located outside contains the second thermo-dependent switch and two electromagnetic relays similar to the first. The second section carries out seasonal switching of the operating mode of the cooler and heater, and the first one maintains the working temperature in the refrigerator year-round. To increase the resource, the second section of the thermostat is placed in a thermally insulated container.

Description

The utility model relates to domestic refrigerators (without a freezer), designed to store food, and operated year-round in unheated rooms. In fact, such a refrigerator is a thermostat that maintains a temperature of (5 + 3) C in the working volume at an external temperature that varies in the range of, for example, +30 C. It is obvious that such a thermostat must contain a cooler, a heater and a temperature regulator in a thermally insulated case. At the same time, it should be economical, convenient in operation and provide storage of any products.

Known devices for year-round storage of agricultural products in unheated rooms, for example, on the balcony or loggia of a residential building. In the patent RU 2011331 C1, IPC A01F 25/00, 1992, an EK-1 thermal container is described comprising a cooler, a heater, a temperature regulator and a ventilation device.

However, this thermal container is very difficult to manufacture and especially to operate. So, the ventilation device contains in the housing at least 6 holes with ground stoppers, which must be inserted / removed several times during the year. The temperature regulator is an alcohol thermometer and an eye installed inside the container, and the temperature is adjusted manually by turning on / off several sections of the heater at full or partial power. During off-season, the cooler and heater are manually turned off. However, during these periods there are frosts of up to - (5-10) C. In addition, this container is designed to store only vegetables and fruits (in large packages), and not ordinary food products.

In patent RU 1237877 (A1), IPC F25D 13/00, 1984, a refrigerator is described for storing fruits and vegetables. It contains a cooler, a heater, a thermal relay, a fan, air ducts, and a moisture exchanger. The goal is to reduce energy consumption by preventing the appearance of a snow coat on the cooler evaporator. However, this camera is complex, ineffective in terms of energy saving and requires manual seasonal maintenance. So, in winter and summer, you must manually turn on the heater or cooler, and in the off-season they are turned on together and controlled by a thermal relay. This means that, for example, at an external temperature of -5 ° C, first the heater raises the temperature in the chamber to + 8 ° C, then the thermal relay turns on the cooler, which lowers the temperature to + 2 ° C, then again the heater, etc. Thus, in the off-season, energy consumption is maximum (and this is 25-30% of annual consumption) and it clearly exceeds the savings achieved by eliminating the snow coat. In addition, this camera is not designed to store conventional products.

A known cabinet for storing food products containing a thermally insulated container, two batteries of Peltier thermoelectric modules, a power supply unit for these modules, two fans with external and internal radiators, and an automatic control unit (see the description of Utility Model RU 4368 (U1), IPC F25D, 1995)

However, this device has significant disadvantages. It contains a large number of electrical components and components, which reduces its reliability. In addition, the automatic control unit switches the heating / cooling modes depending on the ambient temperature without inertia, i.e. almost instantly. This leads to the fact that, for example, in the spring, when the temperature during the day can repeatedly change from plus to minus, the automatic control unit will respond to all these changes and switch the operating mode, which reduces the resource of the device. But the main disadvantage of this device is the increased power consumption. In the cooling mode, Peltier elements in comparison with the compression chillers used in household refrigerators consume significantly more electricity. So, from the graph on page 1 of the Appendix it follows that a single-stage compressor at an evaporation temperature of -20 ° C has a COP coefficient - coefficient of cooling efficiency - equal to 3, while this coefficient for a thermoelectric refrigerator (see page 2 of the Appendix) is 0.3 ÷ 0.5, and the smaller value refers to larger refrigerators. In heating mode, the difference is even greater. That is why large-volume thermoelectric refrigerators are not commercially available.

In patent RU 2317495 C2, IPC F25D 29/00, 2003, a refrigerator with a heated internal volume is described. It contains a refrigerator and a freezer with one common cooler, an electric heater and a temperature controller located inside the refrigerator. The refrigerator is designed to operate in low ambient temperatures. In this case (in the absence or with the electric heater turned off), the cooling chamber needs little cooling, and the thermostat turns on the cooler for a short time, which leads to an increase in the temperature inside the freezer. Turning on the electric heater raises the temperature in the refrigerator, while the thermostat turns on the cooler for a longer time, as a result of which the temperature in the freezer is maintained at the required level.

A significant drawback of this refrigerator is its excessive power consumption. So, at an ambient temperature of, for example, -10 ° C, the heater and cooler will turn on one after the other, and the refrigerator will continuously consume electricity. Such refrigerators are unpromising, since currently freestanding freezers and refrigerators are widely used.

It is well-known household refrigerators (without a freezer) that work in heated rooms (mainly in kitchens), for example, the Atlant MX-5810-62 refrigerator, Biryusa 542, Saratov 504, etc., they are reliable and convenient to operate.

The Atlant MX-5810-62 refrigerator was selected as a prototype. It contains a heat-insulated case with a door and shelves for storing products, a cooler of compression type, a temperature regulator and an automatic defrosting system for the evaporator, which eliminates the formation of a snow coat and reduces the energy consumption of the refrigerator.

However, this refrigerator has significant drawbacks. Since it is operated year-round at a temperature of ~ (22 ± 2) ° C, it constantly (at any time of the year) consumes electricity. In addition, it occupies a useful area in the room, which, taking into account the provision of space for a person with the refrigerator door open, is ~ 1 sq.m. Given that the area of kitchens in old-built houses is often -6 square meters, this proportion exceeds 15%. And at present, developers offer one-room apartments with a total area of 19 sq.m. with a loggia of 3,5 sq.m. (e.g. Gosudarev - House - ZhK. sh), where the proportion of each square. meter even more.

Thus, we can expect that the proposed refrigerator will be in demand among owners of the lower price sector of housing.

The objective and technical result of the utility model is a household refrigerator with reduced annual energy consumption, minimum cost and the possibility of its operation in an unheated room.

The solution of this problem and the technical result are achieved by the fact that a domestic refrigerator containing a thermally insulated body with a door and shelves for storing food, a cooler of compression type, an automatic defrosting system for the evaporator and a temperature regulator is equipped with an electric heater, and the temperature regulator is made of two sections, the first the section is a standard 2-pin thermo-dependent switch located inside the refrigerator, and the additional second section contains the same as the first a second thermally dependent switch and two electromagnetic relays, while one heater output is connected to a contact of the first switch connected to one contact of the second switch and one network output of the supply voltage of -220 V, the second network output of the supply voltage is connected to the common power terminals of both relays and to the common the second relay contact, the second contact of the first switch is connected to the second power terminal of the first relay and to one cooler power output, the second contact of the second switch is connected to the second terminal m of the power supply of the second relay, the normally open contact of which is connected to the second output of the cooler power supply, and the normally closed contact is connected to the normally closed contact of the first relay, in addition, the second switch is placed in a heat-insulated container installed outside the housing, and the thermal inertia of the container is selected commensurate with the thermal inertia corps.

The essence of the utility model is illustrated by the accompanying drawings.

In FIG. 1 shows a simplified electrical diagram of a refrigerator. At the same time, such units of a serial refrigerator as a cooler evaporator, automatic defrosting system, thermal and start-up relay, lighting lamp, etc. are not shown.

In FIG. 2 in the table shows the average monthly air temperature in Moscow, as well as the difference of these values with the temperature inside the refrigerator.

In FIG. 1 the following units of the refrigerator are marked: 1 and 2 - standard and additional thermally dependent switches, 3 and 4 - electromagnetic relays, 5 - electric heater, 6 - motor-compressor of the cooler, 7 - insulated container.

Switch 1 is connected to switch 2 by one contact, as well as to one output of heater 5 and one network output of supply voltage ~ 220 V, the second output of supply voltage is connected to the common power terminals of relays 3 and 4 and to the general contact of relay 4. Second contact of switch 1 connected to the second power terminal of relay 3 and with one power terminal of the motor-compressor of cooler 6. The second contact of switch 2 is connected to the second power terminal of relay 4, the normally open contact of this relay is connected to the second power terminal of motor-compressor 6, and cial closed - to the normally closed contact of the relay 3, the common contact of which is connected to the second terminal 5 of the heater.

The device operates as follows.

In summer, at an ambient temperature of + 8 ° C, the contacts of switch 2 are closed, -220 V is supplied to relay 4, the relay is activated, its normally open contacts are closed and cooler 6 is connected to the -220 V power supply. The refrigerator is operating normally - at temperature inside the case + 8 ° C, the contacts of switch 1 close, cooler 6 turns on, the temperature drops to + 2 ° C, the contacts of switch 1 open, the cooler turns off, the temperature rises to + 8 ° C, etc.

In winter, at an ambient temperature of + 2 ° C, the contacts of switches 2 and 1 are open, relays 4 and 3 are de-energized, and the heater 5 is connected to the voltage of -220 V through normally closed contacts of relays 3 and 4. As a result, the temperature inside the refrigerator rises to + 8 ° C and the contacts of switch 1 are closed, the supply voltage of -220 V is supplied to relay 3, when triggered, the power supply to heater 5 is disconnected, the temperature in the refrigerator drops to + 2 ° C and the cycle repeats.

In the off-season, when the average daily ambient temperature is close to the working temperature inside the refrigerator (2 ÷ 8) ° C, the latter may not turn on either heating or cooling at all and not consume electricity.

The operation of such a refrigerator, especially in winter, may be inconvenient for a housewife, as she will have to go out onto the loggia / balcony repeatedly during the day. Therefore, this suggests itself: to install in the kitchen (on the table, on the pedestal) a small refrigerator with a volume of 50 ÷ 80 liters. and load it with products as needed, for example 1 time per week. In this case, in the off-season (if the refrigerator door does not open within a week), switching of the switch 1 inside the refrigerator can occur very rarely, for example, once every few days. But switch 2, installed outside the case and having a slight thermal inertia, will respond to changes in ambient temperature and can switch the summer / winter refrigerator operation mode several times a day. Such a situation is quite likely, for example, in spring (night frost - in the morning the sun warmed the refrigerator body - the wind blew, it started to rain - the sun again). Of course, the number of trips of switch 2 during the year is less than that of switch 1, but it should be noted that its operating conditions (temperature, humidity) are much more complicated, and the standard life is small - 5 years.

To eliminate this drawback, the switch 2 is placed in a thermally insulated container 7, the thermal inertia of which is selected commensurate with the thermal inertia of the refrigerator body, so that the switch 2 is turned on quite rarely during the off-season. This increases the life of the refrigerator, and, in addition, allows you to use a simpler and cheaper switch in it.

The implementation of the proposed device does not present technical difficulties. As an electric heater, for example, a flat flexible silicone heater or a flexible heating element (for example, see, for example, polymemagrev.ru) can be used, switch 2 is identical to the standard switch 1, relays 3 and 4 are selected simply by the value of the switched power, and thermally insulated the container 7 can be made in the form of a box covered with several layers of polypropylene.

In the table of FIG. 2 shows the average monthly temperature in Moscow, as well as its difference with the temperature inside the refrigerator. For the prototype, it is almost constant throughout the year and amounts to ~ (22-5 = 17) ° C. For the proposed refrigerator and prototype, this difference is the same in the winter months, clearly lower in other months, and almost equal to zero in 4 and 10. Therefore, we can assume that the annual energy savings of the proposed refrigerator for the middle zone of the Russian Federation will be ~ (25 ÷ 30)%.

Thus, the task is completed and the technical result is achieved.

APPENDIX

Chart 1. Comparison of the COP coefficient (refrigeration coefficient) for two-stage and one-stage screw compressor units (both with economizers)

COP is the ratio of the refrigeration capacity of a compressor unit to the electrical power it consumes (COP = Qo / Pe). The graph shows that at a refrigerant boiling point of -40 ° C, a single-stage screw compressor unit consumes 17% more electricity than a two-stage one, and a refrigerant boiling mode of -40 ° C is the most common in freezing systems of meat and poultry processing enterprises.

As an example, I will cite the following figures: a single-stage screw compressor unit with an economizer with a cooling capacity of 454.5 kW consumes 306.9 kW of electricity, and its closest two-stage analogue with a cooling capacity of 455.2 kW - 258.1 kW.

Having adopted an average annual operating time of compressor units of 5 thousand hours and an average cost of 1 kW of electricity 3.5 rubles.

- CAPILLARY BLOCK

- DEFECTS FULL NO

- FROST

- REPLACEMENT

- COMPRESSOR

- EVAPORATOR REPAIR

- REPLACING THE EVAPORATOR

- FILLING FREON

- REPAIR TOOL

- DO IT YOURSELF

- VIOLATION OF TECHNOLOGY

- INTERESTING FACTS

- Home

- Thermoelectric chillers.

Thermoelectric chillers.

The essence of thermoelectric cooling is that when direct current passes through a thermal battery composed of two different thermoelement materials (TEM) connected in series, heat is released from one side of the battery and heat is absorbed from the opposite. A single TEM element is a thermocouple, which includes one p-type branch and one n-type conductivity branch. The branches are interconnected using a patch plate made of copper. Semiconductors based on bismuth, tellurium, antimony, and selenium are traditionally used as the material of branches. A thermoelectric module is a collection of thermocouples electrically connected in series. Thermocouples are placed between two flat ceramic plates made on the basis of aluminum oxide. The number of thermocouples can vary over a wide range (from several to hundreds of pairs), which allows you to create a TEM of almost any refrigerating capacity - from tenths to hundreds of watts. Some junctions of this battery are cooled, while others are heated. Thus, the role of the working substance - the heat carrier - is performed by direct electric current. By placing the cold junctions of the thermopile in a refrigerated medium, it is possible to easily transfer heat from the refrigerator to the colder environment surrounding the cold junctions. The advantages of thermoelectric cooling is that there are no moving parts, which means that the unit is quiet, the ability to precisely control the degree of cooling is proportional to the magnitude of the current. When changing the polarity of the direct current, the hot and cold plates change places. The efficiency of the ongoing processes is characterized by the coefficient of performance, equal to the ratio of the cooling power of the module to the electrical energy consumed by it, and characterizing the efficiency of the ongoing processes. For thermoelectric devices, the COP is on average 0.3 ... 0.5. Currently, the production of domestic refrigerators using thermoelectric cooling is developing rapidly, the well-known firms Pozis, Atlant, factories in Murom, and Miass produce a fairly wide range of refrigerators. They practically do not require maintenance; thermoelectric modules have a guarantee of up to 25 years.

Absorption refrigeration machine

The principle of operation of the absorption-type refrigeration unit is as follows. The concentrated solution is constantly heated in the steam generator 1 to the boiling point of some heat source (electric, gas, etc.) since the boiling point of the refrigerant is much lower than the boiling point of the solvent (absorbent)

Refrigerator of the future

Claims (1)

A household refrigerator containing a thermally insulated case with a door and shelves for storing products, a compression type cooler, an automatic defrosting system for the evaporator and a temperature regulator, characterized in that it is equipped with an electric heater and the temperature regulator is made in two sections, the first section being a standard -contact thermo-dependent switch located inside the refrigerator, and the second additional section contains a second thermo-dependent switch and two electric relay, in this case, one heater output is connected to the contact of the first switch connected to one contact of the second switch and one network output of the supply voltage ~ 220 V, the second network output of the supply voltage is connected to the common power outputs of both relays and to the common contact of the second relay, the second the contact of the first switch is connected to the second power terminal of the first relay and to one cooler power terminal, the second contact of the second switch is connected to the second power terminal of the second relay, normally open the cycle of which is connected to the second output of the cooler power supply, and normally closed, with the normally closed contact of the first relay, in addition, the second switch is placed in a thermally insulated container installed outside the case, and the thermal inertia of the container is selected commensurate with the thermal inertia of the case.

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