Refrigerator with a variable speed compressor and a method for controlling the compressor speed
Refrigerator ( 200, 210 ) comprising a compartment ( 13 a ) for storing foodstuff; a cooling system ( 200, 210 ) comprising an evaporator ( 12 a ), a condenser ( 14 ) and a variable speed compressor ( 10 ), the cooling system ( 200, 210 ) being adapted to go through a refrigeration cycle at certain intervals. A control system ( 11 ) is configured to control the variable speed compressor ( 10 ) during the refrigeration cycle, the control system ( 11 ) being based on a minimum speed ( 36 ) and a required speed ( 22 ), whereby the control system ( 11 ) is configured to set the compressor speed ( 35 ) to the highest speed of both the minimum speed ( 36 ) and the required speed ( 22 ). Such control system ( 11 ) provides an improved performance of the cooling system ( 200, 210 ), maintaining a balance of different temperatures inside the refrigerator ( 100, 110 ).
1 . A refrigerator ( 100 ; 110 ) comprising
a compartment ( 13 a ) for storing foodstuff,
a cooling system ( 200 ; 210 ) comprising an evaporator ( 12 a ); a condenser ( 14 ) and a variable speed compressor ( 10 ), the cooling system ( 200 ; 210 ) being adapted to go through a refrigeration cycle at certain intervals;
a control system ( 11 ) is configured to control the variable speed compressor ( 10 ) during the refrigeration cycle based on values of a minimum speed ( 36 ) and a required speed ( 22 ), whereby
when the minimum speed ( 36 ) is lower than the required speed ( 22 ) then the control system ( 11 ) is configured to set the compressor speed ( 35 ) to a speed value equal to the required speed ( 22 ); and
when the minimum speed ( 36 ) is higher than the required speed ( 22 ) then the control system ( 11 ) is configured to set the compressor speed ( 35 ) to a speed value equal to the minimum speed ( 36 ); and
wherein the control system ( 11 ) is configured to set an actual speed of the variable speed compressor ( 10 ) to the speed value.
2 . The refrigerator ( 100 ; 110 ) according to claim 1 , wherein the control system ( 11 ) is configured to control the variable speed compressor ( 10 ) in a step-by-step manner.
3 . The refrigerator ( 100 ; 110 ) according to claim 1 , wherein the control system ( 11 ) is configured to calculate the minimum speed ( 36 ) in relation to an elapsed time from the start of the refrigeration cycle.
4 . The refrigerator ( 100 ; 110 ) according to claim 3 , wherein the control system ( 11 ) is configured to further calculate the minimum speed ( 36 ) based on temperature settings.
5 . The refrigerator ( 100 ; 110 ) according to claim 1 , wherein the control system ( 11 ) is configured to calculate the required speed ( 22 ) based on temperature parameters, comprising the difference between a measured temperature and a set temperature.
6 . The refrigerator ( 100 ; 110 ) in accordance with claim 1 , wherein the control system ( 11 ) comprises a switch control ( 31 ) configured to start the variable speed compressor ( 10 ) at the onset of the refrigeration cycle and stop the variable speed compressor ( 10 ) at the end of the refrigeration cycle.
7 . The refrigerator ( 100 ; 110 ) according to claim 1 , wherein the refrigerator comprises a second compartment ( 13 b ).
8 . The refrigerator ( 100 ) according to claim 7 , wherein the compartment ( 13 a ) and the second compartment ( 13 b ) are connected through a channel ( 15 ), and the cooling system ( 200 ) comprises a fan ( 16 ) to generate forced air circulation between the compartment ( 13 a ) and the second compartment ( 13 b ).
9 . The refrigerator ( 110 ) according to claim 7 , wherein the cooling system ( 210 ) comprises a second evaporator ( 12 b ) in series with the evaporator ( 12 a ).
10 . The refrigerator ( 110 ) according to claim 9 , wherein the evaporator ( 12 a ) is connected to the compartment ( 13 a ), which is a freezer compartment, and the second evaporator ( 12 b ) is connected to the second compartment ( 13 b ), which is a fresh food compartment, and the flow path of a refrigerant fluid is from the evaporator ( 12 a ) to the second evaporator ( 12 b ).
11 . The refrigerator of claim 1 , wherein the control system comprises a memory, the memory being configured to store a minimum speed graph plot for setting the minimum speed.
12 . A method of controlling a variable speed compressor ( 10 ) in a cooling system ( 200 ; 210 ) of a refrigerator ( 100 ; 110 ), the cooling system ( 200 ; 210 ) going through a refrigeration cycle at certain intervals, comprising:
(a) starting the refrigeration cycle;
(b) calculating a minimum speed ( 36 );
(c) calculating a required speed ( 22 );
(d) comparing the minimum speed ( 36 ) and the required speed ( 22 );
(e) setting the compressor speed to the highest speed of the minimum speed ( 36 ) and the required speed ( 22 );
(f) evaluating when the end of the refrigeration cycle is reached, and performing steps (a) to (e) until the end of the refrigeration cycle is reached; and
(g) stopping the refrigeration cycle when the end of the refrigeration cycle is reached.
13 . The method of claim 12 , wherein a speed graph is visualized during the refrigeration cycle.
14 . The method of claim 12 , wherein the step (b) calculating the minimum speed ( 36 ) is made by determining an elapsed time from the start of the refrigeration cycle.
15 . The method of claim 14 , wherein the step (b) calculating a minimum speed ( 36 ) includes the consideration of temperature settings.
16 . The method of claim 12 , wherein the step (c) calculating a required speed ( 22 ) is made by determining temperature parameters, comprising the difference between a measured temperature and a set temperature.