Features of the thermostat operation of the refrigerator

refrigerators Any model of a modern refrigerator has two thermal relays that differ in the principle of operation and functionality. The first relay of the refrigerator is responsible for compressor overheating, and the thermostat for the refrigerator monitors the temperature range of the evaporator itself. Temperature regulators are mechanical and electrical.

For many years, despite the technical progress and new achievements, the use of the thermostat for a refrigerator still remains unchanged. Simplicity and reliability are the main reasons for using a temperature controller for a modern refrigerator.

Thermostat functions

The thermostat inside the refrigerator is a kind of bell, with the signal of which the whole complex technological process is put into operation. If the call does not sound, the mechanism does not work, the development of cold does not begin!

The principle of operation of the

thermostat It is reliably known that the average duration of a high-quality bellows operation is 5 years. Therefore, it makes no sense to talk about the ten-year operation of equipment. As you know, the work of the refrigerator consists of 4 phase states of freon, namely:

• Compression.
• Condensation.
• Extensions.
• Evaporation.

In order to understand how freon helps to get a low temperature, let's consider the process of its conversion in more detail.

Inside the evaporator, the lowering of the temperature of the freon goes into a gaseous state, which it easily changes in the capillary tube of the thermal switch. As soon as the heat reading changes, the temperature will become less than the threshold, freon under pressure will change to liquid. Such a change in state contributes to a sharp decrease in pressure, and, consequently, to straightening the bellows.

At this stage, the contacts are closed, the control voltage is canceled from the thermal relay of the engine. The refrigerator stops producing cold evenly until the temperature switch activates.

At this stage, the freon is converted to steam, the pressure on the bellows increases sharply, which leads to the closure of the contacts to start the engine of household appliances.

Important:

Despite the duration of the Freon tube, the change in the state of aggregation of a substance occurs exclusively at the end adjacent to the evaporator. Thus, the quality of operation of the refrigerator temperature relay is influenced by the contact density. And it is provided by means of sealant, special glue.

If the temperature relay failed, then replacing it for the master is not difficult. To this end, it is recommended to replace the element with the same model and type. Otherwise, the thermal state of the refrigeration equipment will differ dramatically, and the result of the equipment operation is not very pleasing.

Experienced masters know that the thermal state of the relay can be adjusted. Thus, with dignity out of the situation, customizing the work of the chiller regulator for the user.

The control knob, which is rotated to regulate the temperature, has a direct effect on the spring of the thermal switch, and accordingly on the thermal state of the unit.

However, this method of operation of the device cannot be used for electronic devices.

Where is the thermostat

The owners of refrigeration equipment with mechanical thermostat, are familiar with it in absentia. In most cases, during the installation, moving, furniture rearrangements to facilitate the process, the owners took the temperature relay with their hands, without even knowing it. Touched the temperature control knob to switch the temperature mode or the rotary mechanism of the relay itself.

Today it consists of two main elements, the appearance of which suggests the purpose and functionality:

• A box consisting of control and actuating mechanisms.
• Oblong, thin capillary.

So, let's look at the intricacies of the temperature controller in order.

The box consists of a hermetically sealed bellows, which is a cylindrical metal harmonica that reacts to temperature changes in the environment, changing pressure through its own linear dimensions.

For a general idea, it can be noted that the appearance of the accordion is similar to a metal corrugated tube( often used in household appliances).However, its complete isolation from the outside world testifies to the integrity and precise definition of indicators.

When the ambient pressure increases, the accordion shrinks, and when lowered, it stretches accordingly. The design also includes a spring that modifies the reaction of the bellows in accordance with the present pressure.

Manufacture of bellows, regardless of size and future use of the same. For the manufacture of used only high quality steel, which is drawn into a cylindrical shape. However, the most interesting part manufacturing process takes place further.

The resulting metal cylinder is installed inside a special machine, in which, under a press, the metal sheet is squeezed and straightened under a precisely defined force. Thus, an accordion is formed that does not individually possess elastic properties, for example, as a spring. The finished accordion is easy to deform: stretching, compression, deformation.

To balance the external pressure on the bellows, the possibility of using the measurement technique, gas is pumped into it. Thus, any impact on the bellows can lengthen or stretch, change its shape.

However, it is obvious that a temperature relay with a sensitive element will operate at any temperature. It does not guarantee convenience. It is much more pleasant when the device with the installed regulator changes the threshold depending on the temperature inside the refrigerator chamber.

To accomplish this task, a spring is screwed over the bellows. She wraps a spiral around it, fixing the ends in the same place as the bellows. Therefore, the spring tension has an effect on the threshold for the start of the sensitive element.

Today there are models with one or several springs, the use of which depends on where it is used: in freezers, directly for the refrigerator.

Electronic temperature relays for

refrigerators Thermal switches of electronic type enable more flexible control of the entire system. In this case, a special resistor or thyristor acts as a sensitive element. The main disadvantage of using electronic relays in refrigerators with high energy consumption is the lifetime.

The most popular electronic temperature relays are used for refrigerators with linear compressors, in which thermal readings are achieved along with low energy consumption, noise level, and dimensions.

That is why today for the production of cooling equipment linear compressors are used, which continuously work, precisely maintain the set temperature.

As you can see, mechanical and electronic thermostats differ in sensitivity, durability, and reliability. Therefore, choosing home appliances for purchase, it is worth paying special attention to the type of temperature switch.