REFRIGERATOR COOLING

Abstract: In the cooling system of a two-door type refrigerator with freezer (2) and fresh food compartments (1), the total running time (tquick) of the Quick Freeze is equal to the sum of the quick freeze 100% running time (t100) and the quick freeze cyclic running times (tcycle). The duration and temperature values at which the compressor (7) has to be operated for the quick freeze process and the operational period of the heater (5) placed in the fresh food compartment (1) to avoid the decrease of the inner temperature of the fresh food compartment (1) during quick freezing, as well as the temperature value at which the heater has to be operated are determined in the control unit (8).

Description: REFRIGERATOR COOLING The present invention is related to providing the freezing capacity in the freezer compartment, at least in conformity with the standards, without lowering the interior temperature in the fresh food compartment below the desired level, in two-door type refrigerators having both the freezer and fresh food compartments. The "Quick Freeze" operation is used in order to lower the temperature of the food placed in the freezer compartment, rapidly to -18°C. The quick freeze capacity is the maximum amount of food that can be frozen in a certain time period, during the quick freeze process. When the quick freeze process is started, the thermostat reaches its highest value and the refrigerator operates at 100% capacity. By delaying the compressor operational period, the freezer compartment can reach the desired freezing capacity. However, in this case the inner temperature of the fresh food compartment droops below the desired level and causes the freezing of the fresh food. In the known technique, in order to avoid this undesired situation the fresh food and freezer compartments are cooled by separate cooling circuits, using two compressors. Furthermore, this problem is solved by reducing the quick freezer capacity. In another known technique, this problem has been solved by changing the dimensions of the evaporator in the fresh food compartment. However this change increases the energy consumption. The object of the present invention is to increase the freezing capacity of the double-compartment type refrigerator, the cooling system of which, has been designed as a single cooling system with a single compressor and a single control center. Another object of the invention is to avoid the freezing of the food in the fresh food compartment, by preventing the inner temperature of the fresh food compartment from falling below the desired level. An embodiment of the refrigerator cooling, realized in order to attain the objects of the invention is illustrated in the attached drawings, wherein: Figure 1, is the layout of the evaporator and heater positions; Figure 2, is the flow chart of the cooling cycle control; Figure 3, is the graphic showing the refrigerator cooling cycle operating in the quick freezer mode; Figure 4, is the flow chart of the alternative cooling cycle control; Figure 5, is the graphic showing the alternative cooling cycle operating in the quick freezer mode. The components shown in the drawings have the following numbers; 1. Fresh food compartment 2. Freezer compartment 3. Fresh food compartment evaporator 4. Freezer compartment evaporator 5. Heater 6. Temperature Sensor 7. Compressor 8. Control Unit In the cooling system of a two-door type refrigerator with freezer (2) and fresh food compartments (1), the total running time (t qUιCk ) of the Quick Freeze is equal to the sum of the quick freeze 100% running time (tioo) and the quick freeze cyclic running times (t cyc ι e ). The duration and temperature values at which the compressor (7) must be operated for the quick freeze process and the operational period of the heater (5) placed in the fresh food compartment (1) to avoid the decrease of the inner temperature of the fresh food compartment (1) during quick freezing, as well as the temperature value at which the heater has to be operated are determined in the control unit (8). An embodiment of the refrigerator quick freeze function is illustrated in Figures 2 and 3, and will be described in detail as follows: In the cooling system of a two-door type refrigerator having the freezer (2) and fresh food compartments (1) when the user presses the quick freeze button (101), the quick freeze process starts and during this process, the control unit (8) performs the below explained operations in order to keep the inner temperature of the fresh food compartment (1) within a range (TMax . T M m), determined by the manufacturer or by the standards. After this initial step (101), the 100% running time (tioo) of the quick freeze function and the estimated duration (ti) of quick freezing, determined by the manufacturer are compared in Step 102. As the result of this comparison, if the 100%) running time (tioo) of the quick freeze function is greater than the estimated duration (ti) of quick freezing, determined by the manufacturer, the compressor (7) is operated at 100% capacity during the quick freeze 100% running time (tioo), in Step 103. In step 104, the temperature sensor (6) placed in the fresh food compartment (1) reads the inner temperature of the said compartment (1) and the control unit (8) compares the values thus obtained, with the upper limit value (T Max ) of the required temperature range for the fresh food compartment determined by the manufacturer. If the inner temperature value in fresh food compartment (1) that is read by the sensor (6) is greater than the upper limit value ( Max ) of the required temperature range for the fresh food compartment determined by the manufacturer, the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled, is closed in Step 105 and Step 108 wherein the cyclic running time (t cycle ) of the quick freeze is compared with the estimated quick freeze operation time (t \ ) starts. In Step 108, if the estimated quick freeze operation time (ti) determined by the manufacturer is greater than the cycle running time (t cyc ι e ) of the quick freeze, the quick freeze operation is terminated and normal cooling is carried on. Otherwise, i.e. if the estimated quick freeze operation time (ti) determined by the manufacturer is smaller than the cyclic running time (t cyc ι e ) of the quick freeze, Step 102 starts and the 100%) running time (tioo) of the quick freeze function and the estimated duration (ti) of quick freezing, determined by the manufacturer are compared. If the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the upper limit value (T a ) of the required temperature range for the fresh food compartment determined by the manufacturer in Step 104 then the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is compared with the lower limit value (T MIΠ ) of the required temperature range for the fresh food compartment determined by the manufacturer in Step 106. In Step 106, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the lower limit value (T MIII ) of the required temperature range for the fresh food compartment determined by the manufacturer, the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled, operates in Step 107 then Step 108 starts. In Step 102 wherein the 100%) running time (tioo) of the freeze function and the estimated duration (ti) of quick freezing, determined by the manufacturer are compared, if the 100% running time (tioo) of the quick freeze function is smaller than the estimated duration (tj) of quick freezing, determined by the manufacturer, step 104 starts and the temperature sensor (6) placed in the fresh food compartment (1) reads the inner temperature of the said compartment (1) and these values are compared with the upper limit value (T Max ) of the required temperature range for the fresh food compartment determined by the manufacturer. If the inner temperature of the said compartment (1) is bigger than the upper limit value (T ax) of the required temperature range for the fresh food compartment determined by the manufacturer, the compressor (7) operates in Step 109 and then Step 108 starts. In Step 104, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the upper limit value (T Ma χ) of the required temperature range for the fresh food compartment determined by the manufacturer; Step 106 starts and the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is compared with the lower limit value (T IΠ) of the required temperature range for the fresh food compartment determined by the manufacturer. In Step 106, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the lower limit value (T M - n ) of the required temperature range for the fresh food compartment determined by the manufacturer, the compressor (7) is kept at "OFF" position in all cases and then Step 108 starts. In step 106, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is greater than the lower limit value (T IΠ ) of the required temperature range for the fresh food compartment determined by the manufacturer, the program determined by the control unit (8) is completed in Step 108 (Fig. 2 and Fig 3). Another embodiment of the refrigerator quick freeze function is illustrated in Figures 4 and 5 and will be described in detail as follows: In the cooling system of a two-door type refrigerator with freezer (2) and fresh food compartments (1), the control unit (8) maintains the inner temperature of the fresh food compartment (1) within the temperature range (T MBX , T MIΠ ) as determined by the manufacturer or by the standards, during the quick freeze process by operating the compressor (7) at 100% capacity and by operating the heater (5) cyclically when the quick freeze button (201) is pressed. The process is illustrated in Figure 4. In this case, the total running time (t quιck ) and 100% capacity running time (tioo) of the Quick Freeze are equal. During this period, the compressor (7) works at 100% capacity. The control unit (8) maintains the inner temperature of the fresh food compartment (1) within the temperature range (T Max - T MIΠ ) defined by the manufacturer or by the standards, during the quick freeze operation. In step 202, the compressor (7) runs at 100% capacity during the 100% capacity running time (tioo) of the Quick Freeze; in Step 203, the temperature sensor (6) placed in the fresh food compartment (1) reads the inner temperature of the said compartment (1) and these values are compared with the upper limit value (T Max ) of the required temperature range for the fresh food compartment determined by the manufacturer. If the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is greater than the upper limit value (T MOX ) of the required temperature range for the fresh food compartment determined by the manufacturer, the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain the required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled, is closed in all cases in Step 204 and Step 207; wherein the total running time (t quιck ) and estimated quick freeze operation time (ti) determined by the manufacturer are compared, starts. In Step 207, if the estimated quick freeze operation time (ti) determined by the manufacturer is greater than the total running time (t quiCk ), the quick freeze operation is terminated and normal cooling is carried on. Otherwise, i.e. if the estimated quick freeze operation time (ti) determined by the manufacturer is smaller than the total running time (t qu -ck), the process returns back to Step 202. In Step 203, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the upper limit value (T M x ) of the required temperature range for the fresh food compartment determined by the manufacturer, step 205 where the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is compared with the lower limit value (T M in) of the required temperature range for the fresh food compartment determined by the manufacturer, starts. h Step 205, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the lower limit value (T MJΠ ) of the required temperature range for the fresh food compartment determined by the manufacturer, the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain the required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled operates in Step 206, then Step 207 starts. In Step 205, if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is greater than the estimated quick freeze operation time (t]) determined by the manufacturer the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain the required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled, is closed in Step 204 and then Step 207 starts (Figures 4 and 5).

Claims: CLAIMS 1. A refrigerator cooling system in a two-door type refrigerator having freezer (2) and fresh food compartments (1), characterised in that the quick freeze operation comprises two steps, namely operating the compressor (7) at 100%) capacity and in cyclic periods and that the control unit (8) provides; the inner temperature of that fresh food compartment (1) to be continuously measured by the temperature sensor (6) placed in the fresh food compartment (1) when the compressor (7) runs at 100%) capacity during the quick freeze 100%) operation time (tioo); the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain the required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled, to be started if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the lower limit value (T M.II ) of the required temperature range for the fresh food compartment determined by the manufacturer, the electrical heater (5) to be closed if the inner temperature value in the fresh food compartment (1) is greater than the upper limit value (T MHX ) of the required temperature range for the fresh food compartment determined by the manufacturer and to be operated cyclically during the quick freeze 100%) operation time (tioo) whereas to be stopped during the quick freeze cyclic running time (t cyc ι e ), when the compressor (7) starts to cyclic operation at the end of the quick freeze 100%) operation time (tioo); the inner temperature of the fresh food compartment (1) to be continuously measured by the temperature sensor (6) placed in the fresh food compartment and the compressor (7) to be stopped if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the lower limit value (T MIΠ ) of the required temperature range for the fresh food compartment determined by the manufacturer, whereas the compressor (7) to be operated cyclical during the cyclic operational time (t cyc ie) if the inner temperature value in the fresh food compartment (1) is greater than the upper limit value (T Ma χ) of the required temperature range for the fresh food compartment determined by the manufacturer. 2. A refrigerator cooling system characterised in that the total quick freeze operation time (t quiC k) is equal to the quick freeze 100% operation time (tioo) and that the control unit (8) provides: the compressor (7) to run at 100%> capacity during the total quick freeze operation time (t q ck ); the inner temperature of the fresh food compartment (1) to be continuously measured by the temperature sensor (6) placed in the fresh food compartment (1); the electrical heater (5) placed in the refrigerator fresh food compartment (1) to maintain the required cooling and to avoid the freezing of the food in case the said compartment (1) is excessively cooled, to be started if the inner temperature value in the fresh food compartment (1) that is read by the sensor (6) is smaller than the lower limit value (T Mιn ) of the required temperature range for the fresh food compartment, but the electrical heater (5) to be closed, and to be operated cyclically during the total operation time (t quiCk ) if the inner temperature value in the fresh food compartment (1) is greater than the upper limit value (TMax) of the required temperature range for the fresh food compartment determined by the manufacturer.

Inventors: ATILLA YUEKSEL, DINGEC HALDUN, GUELDALI YALCIN, ATILLA, YUEKSEL, DINGEC, HALDUN, GUELDALI, YALCIN
Applicants: ARCELIK AS, ATILLA YUEKSEL, DINGEC HALDUN, GUELDALI YALCIN, ARCELIK A.&SCEDIL, ATILLA, YUEKSEL, DINGEC, HALDUN, GUELDALI, YALCIN
Application year: 2000
Main classification: F25D11
IPC codes: F25D11, F25D29