A method for controlling the cooling of a vehicle-mounted refrigerator

Abstract

This invention discloses a cooling control method for a vehicle-mounted refrigerator. The initial compressor speed Nb, variable speed temperature difference Eb, and reduction speed Mb are selected based on the set temperature Ts. When the actual temperature Tc inside the vehicle-mounted refrigerator is Eb degrees Celsius higher than the set temperature Ts, the compressor needs to operate at a higher speed Nb to quickly lower the temperature inside the refrigerator. When the temperature difference between the actual temperature Tc and the set temperature Ts is less than Eb degrees Celsius, the refrigerator already has basic cooling capacity, and the load on the compressor is relatively small. At this point, the compressor speed is reduced to Mb. Although this reduces the cooling efficiency of the refrigerator, the overall energy consumption decreases due to the reduced compressor speed, and the noise is also lower. Furthermore, since the temperature difference between the actual temperature Tc and the set temperature Ts is less than Eb, the decrease in cooling efficiency is limited, ensuring a good cooling effect.

Description

Technical Field

[0001] The present invention relates to the field of vehicle-mounted refrigerators, and particularly to a temperature reduction control method for a vehicle-mounted refrigerator. Background Art

[0002] A vehicle-mounted refrigerator is one of the optional accessories for automobiles. Currently, when a vehicle-mounted refrigerator is operating, the compressor always runs at full power. Although the refrigeration effect is good, the noise is relatively high throughout the process. Moreover, the refrigeration power of the compressor is not in a completely linear state. The higher the compressor power, the better the refrigeration effect, but the comprehensive ratio of its power consumption and refrigeration effect is lower. Summary of the Invention

[0003] To solve the above problems, the purpose of the present invention is to provide a temperature reduction control method for a vehicle-mounted refrigerator, so as to reduce the overall power consumption and noise while ensuring the refrigeration effect of the vehicle-mounted refrigerator.

[0004] The technical solution adopted by the present invention to solve the problem is: a temperature reduction control method for a vehicle-mounted refrigerator, including the following logic:

[0005] The actual temperature inside the vehicle-mounted refrigerator is Tc, and the set temperature of the vehicle-mounted refrigerator is Ts;

[0006] According to the refrigeration range of the vehicle-mounted refrigerator, the set temperature Ts of the refrigerator is classified into (T0, T1], (T1, T2]... (Tn-1, Tn] according to the first classification method, where Ta > Ta-1;

[0007] The rotational speed of the compressor of the vehicle-mounted refrigerator is classified into N1, N2, N3... Nn according to its working speed range, where Na ≤ Na-1;

[0008] Set variable speed temperature differences E1, E2... En, and speed reduction values M1, M2, M3... Mn;

[0009] When the set temperature Ts falls into (Tb, Tb-1], obtain the basic rotational speed Nb of the compressor at this time, and select the variable speed temperature difference Eb and the speed reduction value Mb;

[0010] Compare Tc with Ts. When Tc - Ts ≥ Eb, the compressor runs at the rotational speed Nb. When Tc - Ts < Eb, the rotational speed of the compressor runs at Nb - Mb.

[0011] As a further improvement of the above technical solution, E1 = E2 =... En = 5.

[0012] As a further improvement of the above technical solution, n = 2;

[0013] T0 = -∞, T1 = -5, T2 = +∞;

[0014] N1 = 3500 RPM, N2 = 3500 RPM;

[0015] M1 = 0, M2 = 1000.

[0016] As a further improvement to the above technical solution, the set temperature Ts of the refrigerator is classified into (Y0, Y1], (Y1, Y2]...(Yp-1, Yp] according to the second classification method based on the cooling range of the vehicle refrigerator, where Yc>Yc-1;

[0017] Set the temperature difference between the compressor shutdown temperature as Z1, Z2...Zp, where Za <Za-1,Zp≥0;

[0018] Set the temperature difference between compressor restarts as X1, X2, ..., Xp, where Xa>Xa-1 and X1≥0;

[0019] When the set temperature Ts falls within (Yv-1, Yv], select the compressor shutdown temperature difference Zv and the compressor restart temperature difference Xv;

[0020] Compare Tc with Ts. When Tc≤Ts-Zv, the compressor stops. After the compressor stops, wait for the actual temperature Tc inside the car refrigerator to rise to Tc≥Ts+Xv before restarting.

[0021] As a further improvement to the above technical solution, P = 3; Y0 = -∞, Y1 = -10, Y2 = 0, Y3 = +∞;

[0022] Z1 = 2, Z2 = 1, Z3 = 0;

[0023] X1 = 0, X2 = 1, X3 = 2.

[0024] The beneficial effects of this invention are as follows: The initial speed of the compressor is selected based on the set temperature Ts. When the set temperature Ts is within (Tb, Tb-1], the initial speed is selected as Nb. At this time, when the actual temperature Tc inside the car refrigerator is Eb degrees Celsius higher than the set temperature Ts, it is considered that the temperature difference between the actual temperature Tc inside the car refrigerator and the preset temperature Ts is large. At this time, the compressor needs to work at a higher speed Nb to quickly reduce the temperature inside the car refrigerator. When the temperature difference between the actual temperature Tc inside the car refrigerator and the set temperature Ts is less than Eb degrees Celsius, it is considered that the temperature inside the car refrigerator is close to the preset temperature. At this time, the car refrigerator already has basic cooling capacity. At this time, the temperature difference puts a relatively small load on the compressor. At this time, the compressor speed is reduced to Mb. Although this will reduce the cooling efficiency, the overall energy consumption is reduced and the noise is lower because the compressor speed is reduced. Moreover, since the temperature difference between the actual temperature Tc and the set temperature Ts is less than Eb, the reduction in cooling efficiency is limited, which is sufficient to ensure that it has a good cooling effect. Detailed implementation mode

[0025] In the description of the present invention, the meaning of "a number of" is one or more, the meaning of "multiple" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the base number, and understandings such as "above", "below", "within", etc. include the base number. If the first and second are described, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0026] In the description of the invention, unless otherwise clearly defined, words such as "set", "install", "connect", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0027] A temperature reduction control method for a vehicle-mounted refrigerator includes the following logic:

[0028] The actual temperature inside the vehicle-mounted refrigerator is Tc, and the set temperature of the vehicle-mounted refrigerator is Ts;

[0029] According to the refrigeration range of the vehicle-mounted refrigerator, the set temperature Ts of the refrigerator is classified into (T0, T1], (T1, T2]... (Tn-1, Tn] according to the first classification method, where Ta > Ta-1;

[0030] The compressor speed of the vehicle-mounted refrigerator is classified into N1, N2, N3... Nn according to its working speed range, where Na ≤ Na-1;

[0031] Set variable speed temperature differences E1, E2... En, and speed reduction values M1, M2, M3... Mn;

[0032] When the set temperature Ts falls into (Tb, Tb-1], obtain the basic speed Nb of the compressor at this time, and select the variable speed temperature difference Eb and the speed reduction value Mb;

[0033] Compare Tc with Ts. When Tc - Ts ≥ Eb, the compressor runs at speed Nb. When Tc - Ts < Eb, the compressor speed runs at Nb - Mb.

[0034] The initial compressor speed is selected based on the set temperature Ts. When the set temperature Ts is within (Tb, Tb-1], the initial speed is set to Nb. If the actual temperature Tc inside the car refrigerator is Eb degrees Celsius higher than the set temperature Ts, it is considered that the temperature difference between the actual temperature Tc and the set temperature Ts is large. In this case, the compressor needs to work at a higher speed Nb to quickly lower the temperature inside the car refrigerator. When the temperature difference between the actual temperature Tc and the set temperature Ts is less than Eb degrees Celsius, it is considered that the temperature inside the car refrigerator is close to the set temperature. At this point, the car refrigerator already has basic cooling capacity. The temperature difference puts a relatively small load on the compressor, and the compressor speed is reduced to Mb. Although this will reduce the cooling efficiency, the overall energy consumption is reduced and the noise is lower because the compressor speed is reduced. Moreover, since the temperature difference between the actual temperature Tc and the set temperature Ts is less than Eb, the decrease in cooling efficiency is limited, which is sufficient to ensure good cooling effect.

[0035] In the above method, it is preferable that E1 = E2 = ... En = 5.

[0036] In other implementations, the values ​​of E1, E2...En can be selected as needed.

[0037] For example, E1 = 4, E2 = 4.2, E3 = 4.4, and so on.

[0038] In this scheme, the first embodiment is: n = 2, T0 = -∞, T1 = -5, T2 = +∞;

[0039] N1 = 3500 RPM, N2 = 3500 RPM;

[0040] M1 = 0, M2 = 1000.

[0041] In other implementations, the number of n can be 4, 5, 6, or other options.

[0042] For example, in the second embodiment, n = 5, T0 = -18, T1 = -14, T2 = -8, T3 = 0, T4 = 10, T5 = 20;

[0043] N1=4500RPM, N2=4200RPM, N3=3900RPM, N4=3600RPM, N5=3300RPM;

[0044] M1=500RPM, M2=500RPM, M3=500RPM, M4=500RPM, M5=500RPM.

[0045] For example, in the third embodiment:

[0046] It is described that n = 4, T0 = -18, T1 = -10, T2 = 0, T3 = 10, T4 = 28;

[0047] N1 = 4000 RPM, N2 = 3800 RPM, N3 = 3600 RPM, N4 = 3400 RPM, N5 = 3200 RPM;

[0048] M1 = 500 RPM, M2 = 600 RPM, M3 = 700 RPM, M4 = 800 RPM, M5 = 900 RPM.

[0049] In this solution, if the set temperature Ts is too low, due to the large overall load of the in-vehicle refrigerator, the compressor can be set to always run at the fastest speed, so that the power of the compressor reaches the maximum, that is, the speed reduction value M = 0. Similarly, the variable speed temperature difference E can also be set to the same temperature at each temperature, or can be adjusted according to the set temperature Ts.

[0050] In this solution, it can also be selected that at each set temperature Ts, the speed N of the compressor first runs at the maximum speed, that is, N1 = N2 = N3... Nn. As the set temperature Ts rises, the speed reduction to M gradually increases, that is, Mb > Mb-1. Thus, when Tc - Ts < Eb, the speed N of the compressor decreases as the set temperature Ts increases, as shown in the first embodiment. It can also be selected to set the speed reduction to M to the same value, that is, M1 = M2 =... Mn, and at the same time adjust the base speed N at each set temperature Ts, as shown in the second embodiment. It can also be selected to synchronously form a progressive effect on both the speed reduction value M and the base speed N, as shown in the third embodiment.

[0051] For further optimization, in order to stabilize the actual temperature Tc of the in-vehicle refrigerator near the set temperature Ts, the compressor will be started and stopped. That is, when the actual temperature Tc is lower than the set temperature Ts, the compressor is stopped, and when the actual temperature Tc is higher than the set temperature ts, the compressor is driven to start. However, when the set temperature inside the box is lower, due to the principle of diminishing marginal utility, the cooling effect of the evaporator on the inside of the refrigerator will become relatively slower, and the temperature recovery efficiency will become relatively faster. In current in-vehicle refrigerators, at any set temperature Ts, the upper and lower error temperatures of the compressor start and stop are exactly the same. This results in that when the set temperature Ts is lower, the cycle time for the in-vehicle refrigerator to maintain near the set temperature Ts is shorter, the start and stop frequency of the compressor increases, and the refrigeration accuracy of the in-vehicle refrigerator decreases. To solve this problem, the present invention further optimizes the cooling control method based on the above technology:

[0052] According to the refrigeration range of the in-vehicle refrigerator, the set temperature Ts of the refrigerator is classified into (Y0, Y1], (Y1, Y2]... (Yp-1, Yp] according to the second classification method, where Yc > Yc-1;

[0053] Set the temperature difference between the compressor shutdown temperature as Z1, Z2...Zp, where Za <Za-1,Zp≥0;

[0054] Set the temperature difference between compressor restarts as X1, X2, ..., Xp, where Xa>Xa-1 and X1≥0;

[0055] When the set temperature Ts falls within (Yv-1, Yv], select the compressor shutdown temperature difference Zv and the compressor restart temperature difference Xv;

[0056] Compare Tc with Ts. When Tc≤Ts-Zv, the compressor stops. After the compressor stops, wait for the actual temperature Tc inside the car refrigerator to rise to Tc≥Ts+Xv before restarting.

[0057] According to this logic, the lower the set temperature Ts, the greater the temperature difference when the compressor stops, and the smaller the temperature difference when the compressor restarts. When the temperature inside the car refrigerator drops to the compressor's stop temperature, causing it to shut down, although the residual cold from the evaporator reduces the cooling effect on the car refrigerator, the lower temperature difference between the compressor's stop temperature and the set temperature Ts increases. Therefore, the lowest temperature achievable in this state can still be the same as the lowest temperature achievable when the set temperature is higher. When the car refrigerator returns to the compressor's restart temperature, the compressor needs to go through a transitional state from startup to stability. In this state, although the temperature inside the car refrigerator rises significantly, the upper temperature difference between it and the set temperature Ts is small. Therefore, the highest temperature achievable in this state can still be the same as the highest temperature achievable when the set temperature is higher, thus ensuring the accuracy of the actual temperature Tc inside the car refrigerator.

[0058] In this scheme, Example 1 is as follows:

[0059] P = 3;

[0060] Y0=-∞, Y1=-10, Y2=0, Y3=+∞;

[0061] Z1 = 2, Z2 = 1, Z3 = 0;

[0062] X1 = 0, X2 = 1, X3 = 2.

[0063] Example 2 is where P = 5;

[0064] Y0=-18, Y1=-10, Y2=0, Y3=8, Y4=18, Y5=28;

[0065] Z1=2, Z2=1.5, Z3=1, Z4=0.5, Z5=0;

[0066] X1 = 0, X2 = 0.5, X3 = 1, X4 = 1.5, X5 = 2.

[0067] In Example 3, P = 4;

[0068] Y0=-20, Y1=-10, Y2=0, Y3=0, Y4=20;

[0069] Z1=2, Z2=1.5, Z3=1.1, Z4=0.8;

[0070] X1 = 0.2, X2 = 0.6, X3 = 1, X4 = 1.4.

[0071] In this solution, the specific values ​​can be set according to different models of car refrigerators.

[0072] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct or indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A cooling control method of a vehicle-mounted refrigerator, characterized by comprising: The method comprises the following logic: The actual temperature in the vehicle refrigerator is Tc, and the set temperature of the vehicle refrigerator is Ts; The set temperature Ts of the vehicle refrigerator is classified into (T0, T1], (T1, T2]……(Tn-1, Tn] according to a first classification method, wherein Ta>Ta-1; The compressor speed of the vehicle refrigerator is classified into N1, N2, N3……Nn according to the working speed range, wherein Na≤Na-1; The variable speed temperature difference E1, E2……En and the speed reduction value M1, M2, M3……Mn are set; When the set temperature Ts falls into (Tb, Tb-1], the basic speed Nb of the compressor at this time is obtained, and the variable speed temperature difference Eb and the speed reduction value Mb are selected; The Tc and Ts are compared, when Tc-Ts≥Eb, the compressor runs at the speed Nb, and when Tc-Ts<Eb, the compressor runs at the speed Nb-Mb.

2. The cooling control method of the vehicle refrigerator according to claim 1, wherein E1=E2=……En=5.

3. The cooling control method of the vehicle refrigerator according to claim 1, wherein n=2, T0=-∞, T1=-5, T2=+∞; N1=3500 RPM, N2=3500 RPM; M1=0, M2=1000.

4. The cooling control method of the vehicle refrigerator according to claim 1 or 2 or 3, wherein the set temperature Ts of the vehicle refrigerator is classified into (Y0, Y1], (Y1, Y2]……(Yp-1, Yp] according to a second classification method, wherein Yc>Yc-1; the compressor shutdown temperature lower difference Z1, Z2……Zp is set, wherein Za<Za-1, and Zp≥0; the compressor restart temperature upper difference X1, X2……Xp is set, wherein Xa>Xa-1, and X1≥0; when the set temperature Ts falls into (Yv-1, Yv], the compressor shutdown temperature lower difference Zv and the compressor restart temperature upper difference Xv are selected; the Tc and Ts are compared, when Tc≤Ts-Zv, the compressor is shut down, and after the actual temperature Tc in the vehicle refrigerator rises to Tc≥Ts+Xv, the compressor is restarted.

5. The cooling control method of the vehicle refrigerator according to claim 4, wherein P=3, Y0=-∞, Y1=-10, Y2=0, Y3=+∞; Z1=2, Z2=1, Z3=0; X1=0, X2=1, X3=2. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​