Startup control method for cascade refrigeration system of preservation box

Abstract

The present application provides a startup control method for a cascade refrigeration system of a preservation box, comprising: step S10, powering on the preservation box, and starting the high-temperature compressor of the cascade refrigeration system at a first set frequency RH0; step S11, determining a target operating time of the high-temperature compressor to meet the starting condition of the low-temperature compressor; step S12, determining a target frequency for full-load operation of the high-temperature compressor and the low-temperature compressor of the cascade refrigeration system; step S13, determining a frequency increase / decrease mode, and controlling the high-temperature compressor to increase / decrease the frequency to its target frequency; step S14, when the high-temperature compressor operating time reaches the target time, the low-temperature compressor is started at a second set frequency RL0; step S15, determining a frequency increase / decrease mode, and controlling the low-temperature compressor to increase / decrease the frequency to its target frequency; and step S16, when the actual temperature Td of the compartment reaches the set compartment temperature Ts.

Claims

1. A startup control method for a cascade refrigeration system of a storage box, characterized in that: include: Step S10: the storage tank is powered on, and the high-temperature compressor (A1) of the cascade refrigeration system is started at a first set frequency RH0; Step S11, determining a target operating time of the high-temperature compressor (A1) to achieve a start-up condition for the low-temperature compressor (A2); Step S12, determining the target frequencies of the high-temperature compressor (A1) and the low-temperature compressor (A2) of the cascade refrigeration system when they are running at full load based on the temperature range of the ambient temperature Ta and the temperature range of the compartment set temperature Ts, wherein the target frequencies of the high-temperature compressor (A1) and the low-temperature compressor (A2) when they are running at full load are different in different divided intervals of the temperature range of the ambient temperature Ta and different divided intervals of the temperature range of the compartment set temperature Ts, the lower the ambient temperature Ta and the higher the compartment set temperature Ts, the lower the target frequencies of the high-temperature compressor (A1) and the low-temperature compressor (A2) when they are running at full load, and the higher the ambient temperature Ta and the lower the compartment set temperature Ts, the higher the target frequencies of the high-temperature compressor (A1) and the low-temperature compressor (A2) when they are running at full load; Step S13, determining a frequency adjustment method, and controlling the high-temperature compressor (A1) to adjust the frequency to its target frequency; Step S14: When the running time of the high-temperature compressor (A1) reaches the target time, the low-temperature compressor (A2) is started at the second set frequency RL0; Step S15, determining a frequency adjustment method, and controlling the low-temperature compressor (A2) to adjust the frequency to its target frequency; Step S16: The actual compartment temperature Td reaches the compartment set temperature Ts.

2. The startup control method according to claim 1, characterized in that: In step S10, the high-temperature compressor (A1) of the cascade refrigeration system is started at a first set frequency RH0 according to the actual compartment temperature Td and the compartment set temperature Ts of the compartment of the preservation box; and / or In the step S11, according to the ambient temperature Ta and the actual temperature Td of the compartment, the target time for the high-temperature compressor (A1) to run is determined to achieve the starting condition of the low-temperature compressor (A2); and / or In step S13, a frequency adjustment method is determined based on the suction pressure, exhaust pressure or suction and exhaust pressure difference of the high-temperature compressor (A1), and the high-temperature compressor (A1) is controlled to adjust the frequency to its target frequency; and / or In the step S15, the frequency adjustment method is determined according to the suction pressure, exhaust pressure or suction and exhaust pressure difference of the low-temperature compressor (A2), and the low-temperature compressor (A2) is controlled to adjust the frequency to its target frequency.

3. The startup control method according to claim 2, characterized in that: In step S10, after the freezer is powered on for a first period of time, the actual temperature Td of the compartment is detected. If the actual temperature Td is higher than the set temperature Ts of the compartment by a predetermined temperature value ΔT, that is, Td ≥ Ts + ΔT, the high-temperature compressor (A1) is started at the first set frequency RH0.

4. The startup control method according to claim 3, characterized in that: The first time period is 3 to 15 minutes; and / or The predetermined temperature value ΔT is 3°C.

5. The startup control method according to claim 2, characterized in that: In the step S11 , the target operating time of the high-temperature compressor ( A1 ) is determined based on the temperature range of the ambient temperature Ta and the temperature range of the actual compartment temperature Td.

6. The startup control method according to claim 5, characterized in that: The lower the ambient temperature Ta and the actual compartment temperature Td, the shorter the target operating time of the high-temperature compressor (A1); and the higher the ambient temperature Ta and the actual compartment temperature Td, the longer the target operating time of the high-temperature compressor (A1).

7. The startup control method according to claim 2, characterized in that: In the step S13, Determining the frequency of raising and lowering the high-temperature compressor (A1) according to the pressure range of the exhaust pressure of the high-temperature compressor (A1); and / or The raising and lowering frequency of the high-temperature compressor (A1) is adjusted by detecting the exhaust pressure of the high-temperature compressor (A1) in real time.

8. The startup control method according to claim 7, characterized in that: The higher the exhaust pressure of the high-temperature compressor (A1), the lower the frequency increase rate and the higher the frequency decrease rate; the lower the exhaust pressure of the high-temperature compressor (A1), the higher the frequency increase rate and the lower the frequency decrease rate.

9. The startup control method according to claim 1, characterized in that: The first set frequency RH0 is 30-40 Hz; and / or The second set frequency RL0 is 25-35 Hz.

10. The startup control method according to claim 2, characterized in that: In step S15, Determining the frequency of raising and lowering the low-temperature compressor (A2) according to the pressure range of the exhaust pressure of the low-temperature compressor (A2); and / or The raising and lowering frequency of the low-temperature compressor (A2) is adjusted by detecting the exhaust pressure of the low-temperature compressor (A2) in real time.

11. The startup control method according to claim 10, characterized in that: The higher the exhaust pressure of the low-temperature compressor (A2), the lower the frequency increase rate and the higher the frequency decrease rate; the lower the exhaust pressure of the low-temperature compressor (A2), the higher the frequency increase rate and the lower the frequency decrease rate.

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