KR20070017125A - Refrigerated compartment with controller to place refrigeration system in sleep-mode - Google Patents

Abstract

Refrigeration systems are employed to cool refrigeration compartments in kitchens or restaurants. Electronic refrigeration controllers control various aspects of the refrigeration compartment, including temperature. When the push button is pressed, the "sleep mode" is activated to safely shut down the refrigeration system and turn off the evaporator fan. The user can then stack or remove inventory from the freezing compartment without the cold air being blown against the user. After a predetermined time, the power saving mode ends and the cold air is blown into the freezing compartment.

Sleep Mode, Refrigeration Compartment, Evaporator, Condenser, Solenoid Valve, Expansion Unit

Description

REFRIGERATED COMPARTMENT WITH CONTROLLER TO PLACE REFRIGERATION SYSTEM IN SLEEP-MODE}

The present invention generally relates to a refrigeration compartment that includes a controller that places the refrigeration system in a power saving mode for a predetermined time in response to a signal.

Restaurants, kitchens, and food preparation areas typically include coolers or freezers having refrigerated compartments in which perishable items such as vegetables, meat, and dairy products and food are stored. The freezing compartment is cooled by a remote refrigeration system. The freezing compartment is subsequently accessed to clean, replenish food and store food.

During replenishment of the freezing compartment, warm air may enter the freezing compartment and expose it to temperatures beyond the safety limits set by the food safety management body (such as the Food and Drug Administration), causing corruption. During replenishment, the refrigeration system operates continuously to maintain the temperature in the refrigeration compartment.

Most local and national legislation requires that the evaporator in the refrigeration compartment be equipped with an electrical shut off switch that turns off the evaporator fan when the evaporator has been operating for some extended time. Main power to the refrigeration system can also be shut off. For example, refrigeration systems are usually powered off during cleaning to prevent water from freezing in the evaporator.

The user cuts off power to the evaporator fan and refrigeration system to prevent cold air from being blown against them when storing items in the refrigeration compartment. In certain applications, the refrigeration system is independent of the evaporator fan, and the user may not be able to access to shut off the refrigeration system when power to the evaporator fan is cut off.

When the evaporator fan and refrigeration system are off, the temperature in the refrigeration compartment increases. If the user forgets to operate the refrigeration system and the evaporator fan after leaving the freezing compartment, the temperature in the freezing compartment will increase continuously, leaving food to rot.

In conventional refrigeration compartments, the disconnect switch to the evaporator fan is not always wired correctly and may not normally close the closed liquid line solenoid valve. This may cause slugs of liquid refrigerant to overflow from the compressor causing damage to the compressor and a complete shutdown of the refrigeration system. Until compressor failure is detected, the temperature of the refrigeration compartment may increase. Inaccurate shutdown of the refrigeration system and recovery of operation or leaving the refrigeration system off for long periods of time can cause high power or require the use of power (kilowatts) during pull down mode.

Cold air is blown into the freezing compartment after a predetermined time after entering the power saving mode, and there is a need for a freezing compartment that overcomes other disadvantages of the prior art.

Refrigeration systems are employed to cool the freezing compartment of a restaurant or kitchen. The refrigerant is compressed in the compressor at high pressure and high enthalpy. The compressed refrigerant is cooled in the condenser and expanded at low pressure in the expansion device. The refrigerant then flows through the evaporator and cools the air in the freezing compartment. The refrigerant then returns to the compressor to complete the cycle. The refrigeration compartment includes an electronic refrigeration controller that controls various aspects of the refrigeration compartment including temperature.

When the user stacks or removes inventory from the freezing compartment, the user presses a push button to place the refrigeration system in power saving mode. The refrigeration system is safely shut off and the evaporator is turned off to prevent cold air from being blown into the refrigeration compartment and to the user. After a predetermined time, the power saving mode is terminated, and the refrigerant system and the evaporator fan are operated to cool the freezing compartment so that the temperature of the freezing compartment does not rise above the threshold temperature for a long time.

These and other features of the present invention are well understood from the following detailed description and drawings.

Various features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of the preferred embodiment. The drawings in accordance with the detailed description are schematically described below.

1 is a schematic illustration of a refrigeration system used to cool the refrigeration component of the present invention.

FIG. 2 is a schematic showing the effect of improperly shutting down and starting up an average power (kilowatt) requirement of a facility as a function of time. FIG.

3 is a schematic showing the effect of improperly shutting down and starting up the temperature of an inventory as a function of time.

As schematically shown in FIG. 1, refrigeration system 20 is used to cool refrigeration compartment 30. The freezing compartment 30 may be a freezer or refrigerator in a kitchen or restaurant that cools and stores perishable items such as food. However, it is understood that other uses are possible. For example, refrigeration compartment 30 may be a service cabinet or display case that stores items in a preparation zone before use. Alternatively, freezing compartment 30 may be used for scientific or medical applications.

The refrigerant is compressed at high pressure and high enthalpy in the compressor 22. Thereafter, the compressed refrigerant flows through the condenser 24 and is cooled. Thereafter, the high pressure and low enthalpy refrigerant is expanded to low pressure in the expansion device 26. The expansion device 26 may be an electronic expansion valve or other type of expansion device. After expansion, the refrigerant flows through the evaporator 28 and receives heat from the air in the cooling compartment 30. The fan 32 blows fluid against the evaporator 28, and the fluid releases heat to the refrigerant in the evaporator 28 to heat the refrigerant and cool the fluid in the freezing compartment 30. As an example the fluid is air. Refrigeration system 20 may also include one or more evaporators 28 (main-secondary). If more than one evaporator 28 is employed, the evaporators 28 may operate independently at different times. That is, one evaporator 28 works while the other evaporator 28 does not. Thereafter, the refrigerant returns to the compressor 22 to complete the cycle.

Evaporator fan 32 is separated from refrigerant system 20 to circulate fluid in refrigeration compartment 30. Thus, the fan 32 can operate when the refrigeration system 20 is not working. The fluid can also circulate by natural convection.

In one example the cooler compartment 30 includes a door 34 that allows access to the refrigeration compartment 30. When food is added to or removed from the freezing compartment 30, the door 34 is opened to allow access to the freezing compartment 30. However, the freezing compartment 30 may not include the door 34 as in the case where the freezing compartment 30 is a display case.

The refrigeration system 20 includes an electronic refrigeration controller 42 with time variable circuit characteristics. Electronic refrigeration controller 42 controls various aspects of refrigeration compartment 30, including temperature. The push button 36 is located near the evaporator 28 or near the inlet to the freezing compartment 30. While one push button 36 is illustrated and described, it is understood that one or more push buttons 36 may be employed. Preferably, push button 36 is incorporated into the current Guardian electronic refrigeration controller by Parker-Hannifin.

When the user loads or removes food into or from the freezing compartment 30, the user presses the push button 36 to stop cold air from being blown into the freezing compartment 30. When the push button 36 is pressed, the "sleep mode" is activated through the electronic refrigeration controller 42 to stop the cooling air from being blown into the freezing compartment 30.

The refrigeration system 20 is safely shut down for a predetermined time when the power saving mode is activated. Solenoid valve 40 is located between condenser 24 and expansion valve 26. When the power save mode is activated, the controller 42 provides a signal to close the solenoid valve 40 and the expansion device 26 to reduce the suction pressure of the refrigerant entering the compressor 22. The compressor 22 is cut off by the low pressure switch. The coolant is then pumped from the lower side of the coolant system 20 to prevent the compressor 22 from filling up when the coolant system 20 is up again. While solenoid valve 40 is illustrated and described, it is understood that refrigeration system 20 can be safely shut down without solenoid valve 40. In this example, refrigeration system 20 is safely operated by closing expansion device 26. In the present invention, the refrigeration system 20 is safely shut down and restarted at low load to save energy.

The evaporator fan 32 is turned off when the power save mode is activated to prevent cold air from being blown into the freezing compartment 30. Preferably, the evaporator fan 32 and the refrigeration system 20 are shut down at the same time to prevent cold air from being blown into the freezing compartment 30. However, it is understood that the evaporator fan 32 and the refrigeration system 20 can be shut down independently to prevent cold air from being blown into the freezing compartment 30.

After a predetermined time, the power saving mode ends, and the freezing compartment 30 is cooled again to prevent the freezing compartment 30 from rising above the threshold temperature. The controller 42 sends a signal to open the solenoid valve 40 and the expansion valve 26 to activate the refrigeration system 20. The controller 42 energizes and opens the solenoid valve 40 to allow refrigerant to flow into the compressor 22. Since refrigeration is pumped from the lower side of refrigeration system 20 when solenoid valve 40 and expansion valve 26 are closed, the refrigerant does not overflow in compressor 20. The controller 42 also operates the evaporator fan 32 to blow cold air over the evaporator 28 and back into the freezing compartment 30.

The operator of the kitchen or restaurant can program the duration of the power saving mode in the electronic refrigeration controller 42. Alternatively, the duration of the power saving mode can be programmed when the electronic refrigeration controller 42 is manufactured. This duration can be programmed in the kitchen or restaurant or remotely. For example, the duration of power saving mode is between 5 minutes and 120 minutes. For example, when the freezing compartment 30 is employed in a restaurant or kitchen and turned off during cleaning or replenishment, the power save mode can be programmed with a duration of between 15 and 30 minutes. For example, when the power saving mode occurs on the weekend, the power saving mode may be a long time such as 8 hours to 48 hours. It is understood that power saving modes may have different durations depending on the application.

By properly shutting down the refrigeration system 20 and the evaporator fan 32, the average power requirements of the equipment in the refrigeration system 20 are lowered. By keeping the power demand low, the surface temperature of the item in the refrigeration compartment 30 can be kept low.

FIG. 2 schematically shows the effect of improperly shutting down and starting the refrigeration system 20 with respect to the average power requirements of the installation as a function of time over a four hour frame. The duration between each point is 15 minutes. At point 1, refrigeration system 20 is improperly shut down. At this point, approximately 3.80 kilowatts is consumed. At point 10, the refrigeration system 20 returns to its original state. At point 11, high power is used because the compressor 22 has to pull down the large refrigeration load entering the compressor 22. Average power usage does not return to an initial average of 3.80 kilowatts until point 18 is reached. In other words, the power usage does not return to an initial average of 3.80 kilowatts until 1.75 hours after the compressor 22. As shown in FIG. 3, during this time, the surface temperature of the item in the freezing compartment 30 is increased. In the present invention, refrigeration system 20 and evaporator fan 28 are properly shut down, avoiding a large power average and preventing the surface temperature of the items in the refrigeration compartment from increasing.

The power save mode can be interrupted by pushing push button 36 again. Solenoid valve 40 and expansion valve 26 are opened to allow refrigerant to flow into compressor 22. The fan 32 of the evaporator 28 is also operated to allow cold air to enter the freezing compartment 30. By pressing the push button 36, the power saving mode ends before a predetermined time.

The program algorithm limits the number of times the power saving mode can be operated within a predetermined time frame. When a person presses the push button 36 after the power saving mode ends to resume the power saving mode, the power saving mode is activated when the temperature sensor 38 detects that the cooler compartment 30 has reached a predetermined temperature for a predetermined time. Does not start again. When the temperature sensor 38 detects that the temperature in the freezing compartment 30 has exceeded a predetermined temperature, the power saving mode can be resumed.

Alternatively, the electronic refrigeration controller can limit the duration of subsequent power saving modes so that the refrigeration space 30 is not frozen and left for a long time. The number of times the power saving mode can be started within a predetermined time frame may also be limited.

Events relating to the operation of the power saving mode, the duration of the power saving mode and the temperature in the freezing compartment 30 are recorded and monitored. The time and date associated with these events are also recorded. This information can be accessed in place or remotely.

The foregoing description is an example of the principles of the invention. Those skilled in the art will appreciate that various modifications and variations of the present invention are possible in light of the above teachings. While preferred embodiments of the invention have been disclosed, those skilled in the art will recognize that certain variations fall within the scope of the invention. It is, therefore, to be understood that within the scope of the appended claims, the present invention may be indicated differently than specifically described. For this reason, the following claims should be studied to determine the true scope and content of this invention.

Claims (22)

To maintain the temperature in the freezing compartment, a) cooling the freezing compartment; b) providing a signal to stop step a) for a predetermined time; c) cooling said refrigeration compartment after a predetermined time. The method of claim 1 further comprising the steps of: compressing the refrigerant to high pressure; Cooling the refrigerant; Expanding the refrigerant to low pressure; Heating the refrigerant further; Heating the refrigerant comprises receiving heat from a fluid medium to cool the refrigeration compartment. 3. The method of claim 2, wherein heating comprises employing a first evaporator and a second evaporator. 4. The method of claim 3 including operating the first and second evaporators independently. The method of claim 1, wherein providing the signal comprises pressing a button. The method of claim 1, wherein the predetermined time is between 5 and 120 minutes. The method of claim 6, wherein the predetermined time is between 15 and 30 minutes. The method of claim 1, wherein the predetermined time is between 8 hours and 48 hours. The method of claim 1 wherein the refrigeration compartment is one of a display case and a service cabinet. The method of claim 1 wherein the cryo compartment is employed in the medical and scientific fields. The method of claim 1, further comprising providing a second signal to begin cooling the refrigeration compartment before the predetermined time. The method of claim 1, wherein the method is monitored remotely. The method of claim 1, further comprising sensing a temperature of the refrigeration compartment and providing a second signal to stop cooling after step c), wherein providing the second signal comprises providing the second signal. What happens when the sensing step detects that the temperature in the interior exceeds a threshold. The method of claim 13, wherein providing the second signal occurs after a threshold time value. System to maintain the temperature in the refrigeration compartment, A controller for regulating the temperature in the refrigeration compartment; An evaporator for cooling the freezing compartment, The evaporator stops cooling the refrigeration compartment for a predetermined time in response to a signal. 16. The compressor of claim 15, wherein the compressor is a high pressure refrigerant; A condenser for cooling the refrigerant; And an expansion device to expand the refrigerant at low pressure. The system of claim 15, wherein the evaporator heats the refrigerant by receiving heat from a fluid medium that cools the refrigeration compartment. The system of claim 15, further comprising a button to generate the signal. The system of claim 15, further comprising two or more buttons for generating the signal. The system of claim 15, wherein the predetermined time is between 15 and 30 minutes. 16. The apparatus of claim 15, further comprising a temperature sensor for detecting a temperature in said refrigeration compartment, wherein said evaporator responsive to said second signal after said predetermined time when said temperature sensor detects that a temperature is above a threshold temperature. System to stop cooling the compartment. The system of claim 15 further comprising a second evaporator.

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