WO2012083406A1

WO2012083406A1 - Automatic control module for a compressor

Info

Publication number: WO2012083406A1
Application number: PCT/BR2011/000499
Authority: WO
Inventors: Rogério Soares BRISOLA; Julio Cesar SCHMID
Original assignee: Whirlpool S.A.
Priority date: 2010-12-22
Filing date: 2011-12-22
Publication date: 2012-06-28
Also published as: BRPI1005757A2

Abstract

This invention relates to an automatic control module for a compressor, specifically a compressor having multiple poles (and therefore capable of running at different speeds). The module (2) comprises at least one electrically actuated electrical-contact switch (3) and by at least two electrical-contact switches (4 and 5) actuated on the basis of temperature differences. The link between the electrically actuated electrical-contact switch (3) and the electrical-contact switches (4 and 5) actuated on the basis of temperature differences is used to select the poles of the compressor (1) which are to be electrically powered.

Description

AUTOMATIC CONTROL MODULE FOR COMPRESSOR Field of Invention

The present invention relates to an automatic compressor control module specifically for a multi-pole compressor (therefore capable of operating at different speeds). The disclosed automatic compressor control module makes use of a combination of thermostats and relays in place of the microprocessor electronic boards currently used for this purpose.

Background of the Invention and Description of the Prior Art

Briefly, compressors are known to be industrial equipment used to change the pressure of gaseous fluids. This operating principle even makes it possible to change the temperature of the working fluids. Among its various applications, it is common to note the use of compressors in refrigeration systems.

A conventional refrigeration system, the main purpose of which is to optimize the heat exchange between a refrigerated chamber and the environment, is usually composed of a compressor, a condenser, an evaporator and an expansion device. These components form a closed pneumatic / hydraulic circuit filled with refrigerant (working fluid), which is subject to variations in pressure, temperature and volume.

In this context, it is observed that the basic function of the compressor concerns the compression of the refrigerant in order to heat it and push it to the coil, where it optimizes the heat exchange of the refrigerated chamber with the environment. Compressor operation may vary according to the needs of the refrigeration system, so compressor performance may be constant or cyclic.

In common refrigeration systems, such as a refrigeration system installed in a residential refrigerator (or refrigeration appliance), the compressor actuation is cyclic and binary, ie the compressor remains part of the time on (refrigeration cycle) and part off time (rest cycle). In this case, the switching between these two states is performed according to the temperature of the refrigerated chamber, said compressor being directly switched by the temperature sensor (usually a thermostat) or equivalent device.

This cyclic and torque operation of the compressor, which results sometimes in "high" temperatures, sometimes in "low" temperatures, however, has negative aspects related to the efficiency and power consumption of the refrigeration system.

From this point of view, it can be stated that the refrigeration cycle needs to be extremely long (due to the large temperature gradient), after all, this cycle begins immediately after a rest cycle. Notably, long refrigeration cycles (compressor on) result in large electricity consumptions.

To address these drawbacks, variable capacity compressors (technically known as VCC compressors) were developed. These compressors have multiple operating speeds and can be associated with dedicated control systems. Variable capacity compressors, when introduced into refrigeration systems, can even be combined with real-time control systems capable of determining specific drive speeds based on the temperature of the refrigerated chamber. In this way, not only the compressor speed but also the compressor on and off are determined by the measured temperature.

Therefore, the aforementioned variable capacity compressors, which are capable of differential integral control, are capable of introducing multiple intermediate cycles between the refrigeration and rest cycles, thereby improving the temperature reduction time. In addition to this, variable capacity compressors are also responsible for optimizing power consumption and introducing "dedicated functions" (ultra fast freezing, economical mode, ice making, among others).

Although variable speed compressor-based refrigeration systems are more efficient than conventional compressor-based refrigeration systems, it should be noted that these (variable speed compressor-based refrigeration systems) require specialized hardware and software both high cost of manufacture, implementation and maintenance.

Based on the above content, it is noted that refrigeration systems can be manufactured and / or designed based on simple and limited technology or based on complex and costly technology.

However, the current state of the art is still composed of an intermediate technology. This intermediate technology is based on the use of two speed (4/2 pole) compressors.

A two-speed compressor, as the nomenclature itself induces, is capable of operating at two different speeds. Of course, each of the operating speeds results in its own energy consumption.

Since this technology is introduced in cooling systems, it is possible to increase the efficiency between the "thermal efficiency / electrical consumption" ratio, ie it is possible to obtain a two-cycle refrigeration system with low production cost (in refrigeration systems based on variable speed compressors).

In its conventional operation, the compressor can be switched (on / off) according to the user adjusted value on the thermostat. In the event of an increase in thermal load (eg excessive door openings or the addition of products placed inside the refrigerated chamber) and the room temperature again exceeds the predetermined value, the compressor will change the speed to high level, thus increasing its cooling capacity.

The use of two-speed compressors in refrigeration systems allows, for example, to lower the temperature of the refrigerated chamber faster (maximum speed and higher energy consumption) and to keep the temperature of the refrigerated chamber at an intermediate level (speed minimum and lower power consumption). It is also noteworthy that this technology allows the use of a compressor with lower cooling capacity and energy efficiency.

Having only two speeds, this compressor does not have the efficiency of a variable capacity compressor (with regard to energy saving), after all, it is unable to continually meet the exact need for cooling capacity. However, a two-speed compressor has lower power consumption compared to the standard compressor, as well as lower cost compared to the variable speed compressor, as it does not require dedicated hardware and software for speed change.

Normally, the speed control of a two-speed compressor is performed by a microprocessor electronic circuit. Although this micro-processed electronic circuit is relatively simple, it remains to be seen that its production and maintenance costs are still undesirably high for large-scale production (for economical products). That is, although the two-speed compressor is a more economically viable solution (compared to variable speed compressors), it still has to be reduced in order to be able to apply it to lower cost products, such as home appliances. less sophisticated categories, usually for consumers with relatively lower purchasing power.

For information only, it remains to be mentioned that there are certain solutions for controlling the operating speed of a two-speed compressor, which are described in US 4,041,542; US 3,978,382; and US 4,263,540. However, these documents do not concern a specific solution for switching the operating speeds of a two-speed compressor. In summary, these documents concern ways of controlling the system temperature to prevent damage to equipment (including the compressor itself) or the operation of the cooling system.

Based on all the context explained above, it is evident to note the need to develop a solution and / or technology capable of adding the possibility of switching and / or control of two (or multiple speed) and low compressors. productive costs.

Objectives of the Invention

Thus, it is an object of the present invention to provide an automatic compressor control module (based on refrigerated chamber temperature) capable of replacing existing microprocessor electronic circuits currently used in high efficiency refrigeration systems (with VCC compressors). ).

It is another object of the present invention to lower the cost (manufacture, installation and maintenance) of residential and similar refrigerators based on two (or multiple) compressors.

It is yet another object of the present invention to disclose an automatic compressor control module, in particular for multi-speed (multiple pole) compressors not necessarily associated with refrigeration systems.

Summary of the Invention

The objectives of the present invention are fully achieved by the presently disclosed automatic compressor control module.

The automatic control module for compressor now handled is responsible for automatic switching between the speeds of a multi-speed compressor based on the temperature of a refrigerated chamber. Said automatic compressor control module is fundamentally integrated by at least one electrically operated electrical contact switch (preferably an electronic relay) and at least two temperature difference driven electric contact switches (preferably thermostats).

The combination of the electrically driven electrical contact switch and temperature difference driven electric contact switches is responsible for selecting the compressor poles to be electrically powered.

The operation of the automatic compressor control module (when installed in a vertical or similar refrigerator) is as follows: keeps the compressor off when the temperature of the refrigerated chamber is at or below the working temperature; starts the compressor at low speed (2 poles) when the temperature of the refrigerated chamber is between the normal working temperature and + 20% of this temperature; and starts the compressor at high speed (4 poles) when the temperature of the refrigerated chamber is above 20% of normal working temperature.

Brief Description of the Drawings

The figures listed below comprise:

Figure 1 - illustrates the functional diagram of the automatic control module for compressor (preferred configuration), in "off" state;

Figure 2 - illustrates the functional diagram of the automatic control module for pressor (preferred setting) at "low speed"; and

Figure 3 illustrates the functional diagram of the automatic compressor control module (preferred setting) at "high speed".

Detailed Description of the Invention

Figures 1, 2 and 3 illustrate the preferred but not limiting embodiment of the present invention. In this preferred embodiment a two-speed (2/4 pole) functional compressor 1 is used.

Thus, the compressor 1 is basically comprised of a first induction core 11, a second induction core 12 and a third induction core 13. Induction cores 11, 12 and 13 are associated with each other to conform to each other. four separate terminals "A", "B", "C" and "D" (or four poles).

Terminal "A" consists of one of the induction core terminals 11; Terminal "B" consists of one of the induction core terminals 12; The "C" terminal consists of one of the induction core terminals 13; Terminal "D" consists of a common terminal between induction cores 11, 12 and 13.

The automatic compressor control module, hereinafter referred to as module 2 only, is especially suited to the preferred configuration just described, that is, it is especially suited to a two-speed compressor (4/2 pole compressor).

Thus, and according to the preferred embodiment of the present invention, module 2 is fundamentally integrated by an electronic relay 3 and two double contact thermostats 4 and 5.

Electronic relay 3 provides a command signal input terminal 31, a "common" terminal 32, a "normal closed" terminal 33, and a "normal open" terminal 34. Switching of the internal electrical contact of electronic relay 3 occurs when the command signal input terminal 31 is electrically powered.

Both thermostats 4 and 5 provide a temperature sensor 41 and 51, a "common" terminal 42 and 52, a "normal closed" terminal 43 and 53, and a "normal open" terminal 44 and 54. Switching the electrical contact The internal temperature of each of thermostats 4 and 5 occurs when the temperature captured by the temperature sensor 41 and 51 differs from the set temperature.

Module 2 is electrically connected between compressor 1 and an electrical power supply 6. Of course, this association forms a closed electrical circuit. In this electrical circuit, one of the phases of the power supply 6 is connected to the "common" terminal 42 of thermostat 4; Thermostat 4 "normal open" terminal 44 is connected to thermostat 5 "common" terminal 52; The "normal closed" terminal 53 of thermostat 5 is directly connected to terminal "A" of compressor 1; The "normal open" terminal 54 of thermostat 5 is connected to "common" terminal 32 of electronic relay 3; The "normal open" terminal 34 of electronic relay 3 is connected to the "B" terminal of compressor 1; Terminal "C" of compressor 1 is directly connected to terminal "B" of compressor 1. Terminal "D" of compressor 1 is connected to the power supply phase 6. It is further noted that the signal input terminal 31 of the electronic relay 3 is directly connected to the "normal closed" terminal 53 of thermostat 5.

In this main construction, it is further observed that the temperature sensors 41 and 51 are remotely fixed in a refrigerated chamber 7.

The "state" change of thermostat 4 is automatic and is associated with its temperature sensor 41; Thermostat 5 state change is automatic and is associated with its temperature sensor 51; The relay 3 status signal is associated with the signal (or lack thereof) imposed on the command signal input terminal 31.

Optionally, a starting circuit 8 is also provided which is electrically connected to terminals "B" and "C" of compressor 1. Preferably, the starting circuit 8 is composed of capacitive reactive elements and an electric switch (not shown), which has its drive linked to the "state" switching of the electronic relay 3. The starting circuit 8, as the reference itself induces , aims to assist the drive of induction cores 12 and 13 between terminals "B" and "C" of compressor 1.

The operation of module 2, whose purpose is to automatically control the selection and / or actuation of compressor 1 speeds, is simple.

Generally speaking, thermostat 4 is responsible for the on / off of compressor 1, while thermostat 5 is responsible for selecting compressor 1 speeds (by energizing certain poles thereof). The electronic relay 3 is directly related to the change of "state" of the thermostat 5 terminals, so it can be said that the switching of the electronic relay 3 is indirectly performed by the thermostat 5.

For example, as soon as the entire system is turned on (assuming the temperature of the refrigerated chamber 7 is above the previously established refrigeration temperature), both temperature sensors 41 and 51 are triggered. This causes module 2 to configure an electrical circuit capable of supplying induction cores 12 and 13 (in addition to starter circuit 8). In this situation (illustrated in figure 3), compressor 1 is driven at "high speed".

Once the refrigerated chamber 7 begins to cool, it becomes noticeable at an average temperature where thermostat 5 is deactivated (its contacts return to the initial "state") and thermostat 4 remains activated. This causes module 2 to configure an electrical circuit capable of supplying only the 11 core of compressor 1. In this situation (illustrated in figure 2), compressor 1 is driven at "low speed".

Increasingly, the temperature of the refrigerated chamber 7 tends to drop to turn an ideal level of cooling. At this ideal cooling level (previously set), thermostat 4 is deactivated (thermostat 5 remains deactivated). Consequently, module 2 interrupts any electrical supply previously intended for compressor inductor cores 1 (shown in figure 1) and switches it off.

When compressor 1 is turned off, the refrigerated chamber 7 tends to heat up, reaching the average temperature again. Thereby thermostat 4 is triggered again as described above, resulting in the activation of "low speed" of compressor 1.

Thermostat 5 is only activated when the temperature of the refrigerated chamber 7 reaches levels higher than the average temperature. In this situation, the compressor 1 is driven at "high speed 2", providing rapid cooling of said refrigerated chamber 7.

It remains to be highlighted the possibility of installing a device known as the Time Start Device (TSD) between module 2 and compressor 1. The TSD is an electronic device known to those skilled in the art whose application allows the start circuit switch 8 to be the first few minutes of compressor operation, and then deactivated.

Having described a preferred embodiment example, it should be understood that the scope of the present invention encompasses other possible variations and is limited only by the content of the appended claims, including the possible equivalents thereof.

Claims

1 . Automatic Compressor Control Module FEATURED BY UNDERSTANDING:

automatic switching between the speeds of a multi-speed compressor (1) based on the temperature of a refrigerated chamber (7);

module (2) is integrated by at least one electrical contact switch

(3) electrically operated and at least two temperature difference driven electric contact switches (4 and 5);

The combination of the electric contact switch (3) and the electric contact switch (4 and 5) based on temperature difference is responsible for selecting the compressor poles (1) to be electrically powered.

Module according to Claim 1, characterized in that the electrically operated electrical contact switch (3) comprises an electronic relay.

Module according to Claim 1, characterized in that the temperature-difference-driven electric contact switches (4 and 5) comprise thermostats.

Module according to Claims 1 to 3, characterized in that it keeps the compressor (1) off when the temperature of the refrigerated chamber

(7) is at or below the working temperature.

Module according to Claims 1 to 3, characterized in that it operates the compressor (1) at low speed when the temperature of the refrigerated chamber (7) is between the normal working temperature and + 20% of this temperature. .

Module according to Claims 1 to 3, characterized in that it operates the compressor (1) at high speed when the temperature of the refrigerated chamber is above 20% of the working temperature.

Module according to Claims 1 to 6, characterized in that the module (2) is electrically connected between the compressor (1) and an electrical power supply (6) as a closed electrical circuit; one of the phases of the power supply (6) is connected to the "common" terminal (42) of the thermostat

(4); the "normal open" terminal (44) of the thermostat (4) is connected to the "common" terminal (52) of the thermostat (5); the "normal closed" terminal (53) of the thermostat (5) is directly connected to the compressor terminal "A"(1); the "normal open" terminal (54) of the thermostat (5) is connected to the "common" terminal (32) of the electronic relay (3); the "normal open" terminal (34) of the electronic relay (3) is connected to the compressor terminal "B" (1 ); compressor terminal "C" (1) is directly connected to compressor terminal "B"(1); compressor terminal "D" (1) is connected to the power supply phase (6); The control signal input terminal (31) of the electronic relay (3) is directly connected to the "normal closed" terminal (53) of the thermostat (5).