A control method for a flash evaporator heat pump multi-connected air conditioner

Abstract

The application discloses a control method of a multi-connected air conditioner with a flash evaporator heat pump, which determines the opening and closing of a jet electromagnetic valve SV1 and the amount of jet given by judging the mixing ratio of gas and liquid in the flash evaporator under various conditions according to the load rate of the indoor unit of the multi-connected air conditioner, the operation frequency of the compressor, the exhaust temperature of the compressor and the exhaust superheat degree. The application realizes air supplement only to the air supplement port of the compressor, thereby improving the performance and energy efficiency of the system.

Description

Technical Field

[0001] This invention relates to a control method for a multi-split heat pump unit with a flash evaporator. Background Technology

[0002] With the national promotion of energy conservation and carbon reduction, enterprises need to quickly upgrade and optimize the development of efficient and energy-saving products.

[0003] Currently, most multi-split air conditioning systems on the market still use conventional compressors. Some manufacturers use vapor injection enthalpy-increasing compressors, but they use economizers for superheating. Because the economizers have high resistance, although their energy efficiency is higher than that of conventional compressors, they are not the most efficient.

[0004] Using a high-efficiency flash evaporator as a supplement to vapor injection enthalpy enhancement is undoubtedly the best system. However, given the characteristics of multi-split air conditioners, such as long connecting pipes, high drop, and the ability to over-sizing indoor units by 130%, if the flash evaporator is not properly controlled, it will cause liquid return to the compressor, ultimately damaging the compressor and rendering the system inoperable. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a control method for a multi-split heat pump unit with a flash evaporator, effectively solving the problems mentioned in the background art.

[0006] The technical solution adopted in this invention is:

[0007] A control method for a multi-split heat pump unit with a flash evaporator includes the following steps:

[0008] a) The current operating mode is cooling mode:

[0009] a1) If the indoor unit load activation rate is ≥90% and the compressor operating frequency is ≥60Hz, the jet solenoid valve SV1 will be opened when any one of the following conditions is met:

[0010] (1) Exhaust temperature of T ≥ 80℃;

[0011] (2) Exhaust superheat ≥ 30℃;

[0012] a2) If the indoor unit load activation rate is less than 80% and the compressor operating frequency is <55Hz, the jet solenoid valve SV1 will be closed if any of the following conditions are met for 30 seconds:

[0013] (1) Exhaust temperature of T < 75℃;

[0014] (2) Exhaust superheat ≤ 25℃;

[0015] a3) If the indoor unit load operating rate is 0 and the compressor stops, close the jet solenoid valve SV1;

[0016] b) The current operating mode is heating mode:

[0017] b1) If the outdoor ambient temperature is ≤12℃, the indoor unit load operation rate is ≥90%, and the compressor operating frequency is ≥40Hz, the jet solenoid valve SV1 will be opened when any one of the following conditions is met:

[0018] (1) T exhaust temperature ≥ 50℃ and Pd high pressure ≤ 28 bar;

[0019] (2) T exhaust superheat ≥15℃;

[0020] b2) If the indoor unit load operating rate is ≤80%, the solenoid valve SV1 will be closed if any of the following conditions are met for 30 seconds:

[0021] (1) Exhaust temperature of T ≤ 45℃;

[0022] (2) Compressor operating frequency ≤ 35 Hz;

[0023] (3) P High pressure ≥ 34 bar;

[0024] (4) Exhaust superheat ≤ 10℃;

[0025] (5) Outdoor ambient temperature ≥ 15℃;

[0026] The jet solenoid valve SV1 is located between the intermediate refrigerant gas outlet of the flash evaporator and the intermediate pressure chamber gas inlet of the compressor. The liquid inlet pipe of the flash evaporator is connected to both the capillary tube of the underfloor heating system and the evaporator of the indoor unit. The liquid outlet pipe of the flash evaporator is connected to the condenser of the outdoor unit through an electronic expansion valve.

[0027] Preferably, in a2), when the exhaust temperature of 75 ≤ T < 80°C is maintained for 30 seconds, the jet solenoid valve SV1 maintains its current state.

[0028] Preferably, in a2), when 25 < T exhaust superheat < 30°C for 30 seconds, the jet solenoid valve SV1 maintains its current state.

[0029] Preferably, in a2), when the indoor unit load opening rate is maintained at 80% ≤ 90% for 30 seconds, the jet solenoid valve SV1 maintains its current state.

[0030] Preferably, in a1), the jet solenoid valve SV1 needs to be open for at least 3 minutes before it can be closed.

[0031] Preferably, in b2), when the exhaust temperature of 45 < T < 50°C is maintained for 30 seconds, the jet solenoid valve SV1 maintains its current state.

[0032] Preferably, in b2), when 35 < compressor operating frequency < 40 Hz is maintained for 30 s, the jet solenoid valve SV1 maintains its current state.

[0033] Preferably, in b2), when 28 < P high pressure < 34 bar is maintained for 30 s, the jet solenoid valve SV1 maintains its current state.

[0034] Preferably, in b2), when 10 < T exhaust superheat < 15°C for 30s, the jet solenoid valve SV1 maintains its current state.

[0035] This invention determines the gas-liquid mixing ratio in the flash evaporator under various conditions based on the load rate of the indoor unit of the multi-split air conditioner, combined with the compressor operating frequency, compressor exhaust temperature, and exhaust superheat. This allows for control of the amount of air supplied, thereby enabling air to be supplied only to the compressor's air inlet, thus improving the system's performance and energy efficiency. Attached Figure Description

[0036] Figure 1 This is a system schematic diagram of the multi-unit air conditioner of the present invention. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0038] like Figure 1 The schematic diagram illustrates the system principle of the multi-split air conditioner of the present invention. For this multi-split air conditioner, the present invention provides a control method for a flash evaporator heat pump multi-split air conditioner, comprising the following steps:

[0039] a) The current operating mode is cooling mode:

[0040] a1) If the indoor unit load operating rate is ≥90% and the compressor operating frequency is ≥60Hz, the jet solenoid valve SV1 will open when any of the following conditions are met, and the jet solenoid valve SV1 must remain open for at least 3 minutes before closing: when 75 ≤ T exhaust temperature < 80℃ for 30s, or 25 < T exhaust superheat < 30℃ for 30s, or 80% ≤ indoor unit load operating rate ≤ 90% for 30s, the jet solenoid valve SV1 will remain in its current state:

[0041] (1) Exhaust temperature of T ≥ 80℃;

[0042] (2) Exhaust superheat ≥ 30℃;

[0043] a2) If the indoor unit load activation rate is less than 80% and the compressor operating frequency is <55Hz, the jet solenoid valve SV1 will be closed if any of the following conditions are met for 30 seconds:

[0044] (1) Exhaust temperature of T < 75℃;

[0045] (2) Exhaust superheat ≤ 25℃;

[0046] a3) If the indoor unit load operating rate is 0 and the compressor stops, close the jet solenoid valve SV1;

[0047] b) The current operating mode is heating mode:

[0048] b1) If the outdoor ambient temperature is ≤12℃, the indoor unit load operation rate is ≥90%, and the compressor operating frequency is ≥40Hz, the jet solenoid valve SV1 will be opened when any one of the following conditions is met:

[0049] (1) T exhaust temperature ≥ 50℃ and Pd high pressure ≤ 28 bar;

[0050] (2) T exhaust superheat ≥15℃;

[0051] b2) If the indoor unit load occupancy rate is ≤80%, the solenoid valve SV1 will be closed if any of the following conditions are met for 30 seconds: when 45 < T exhaust temperature < 50℃ for 30 seconds, or 35 < compressor operating frequency < 40 Hz for 30 seconds, or 28 < P high pressure < 34 bar for 30 seconds, or 10 < T exhaust superheat < 15℃ for 30 seconds, the jet solenoid valve SV1 will remain in its current state:

[0052] (1) Exhaust temperature of T ≤ 45℃;

[0053] (2) Compressor operating frequency ≤ 35 Hz;

[0054] (3) P High pressure ≥ 34 bar;

[0055] (4) Exhaust superheat ≤ 10℃;

[0056] (5) Outdoor ambient temperature ≥ 15℃;

[0057] The jet solenoid valve SV1 is located between the intermediate refrigerant gas outlet of the flash evaporator and the intermediate pressure chamber gas inlet of the compressor. The liquid inlet pipe of the flash evaporator is connected to both the capillary tube of the underfloor heating system and the evaporator of the indoor unit. The liquid outlet pipe of the flash evaporator is connected to the condenser of the outdoor unit through an electronic expansion valve.

[0058] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this invention should be considered within the scope of protection of this invention.

Claims

1. A control method for a multi-split heat pump unit with a flash evaporator, characterized in that, Includes the following steps: a) The current operating mode is cooling mode: a1) If the indoor unit load activation rate is ≥90% and the compressor operating frequency is ≥60Hz, the jet solenoid valve SV1 will be opened when any one of the following conditions is met: (1) Exhaust temperature of T ≥ 80℃; (2) Exhaust superheat ≥ 30℃; a2) If the indoor unit load activation rate is less than 80% and the compressor operating frequency is <55Hz, the jet solenoid valve SV1 will be closed if any of the following conditions are met for 30 seconds: (1) Exhaust temperature of T < 75℃; (2) Exhaust superheat ≤ 25℃; a3) If the indoor unit load operating rate is 0 and the compressor stops, close the jet solenoid valve SV1; b) The current operating mode is heating mode: b1) If the outdoor ambient temperature is ≤12℃, the indoor unit load operation rate is ≥90%, and the compressor operating frequency is ≥40Hz, the jet solenoid valve SV1 will be opened when any one of the following conditions is met: (1) T exhaust temperature ≥ 50℃ and Pd high pressure ≤ 28 bar; (2) T exhaust superheat ≥15℃; b2) If the indoor unit load operating rate is ≤80%, the solenoid valve SV1 will be closed if any of the following conditions are met for 30 seconds: (1) Exhaust temperature of T ≤ 45℃; (2) Compressor operating frequency ≤ 35 Hz; (3) P High pressure ≥ 34 bar; (4) Exhaust superheat ≤ 10℃; (5) Outdoor ambient temperature ≥ 15℃; The jet solenoid valve SV1 is located between the intermediate refrigerant gas outlet of the flash evaporator and the intermediate pressure chamber gas inlet of the compressor. The liquid inlet pipe of the flash evaporator is connected to both the capillary tube of the underfloor heating system and the evaporator of the indoor unit. The liquid outlet pipe of the flash evaporator is connected to the condenser of the outdoor unit through an electronic expansion valve.

2. The control method for a multi-split heat pump unit with flash evaporator according to claim 1, characterized in that, In a2), when the exhaust temperature is 75 ≤ T < 80℃ for 30 seconds, the jet solenoid valve SV1 maintains its current state.

3. The control method for a multi-split heat pump unit with a flash evaporator according to claim 1, characterized in that, In a2), when 25 < T exhaust superheat < 30°C for 30 seconds, the jet solenoid valve SV1 maintains its current state.

4. The control method for a multi-split heat pump unit with flash evaporator according to claim 1, characterized in that, In a2), when the indoor unit load opening rate is maintained at 80% ≤ 90% for 30 seconds, the jet solenoid valve SV1 maintains its current state.

5. The control method for a multi-split heat pump unit with a flash evaporator according to claim 1, characterized in that, In the aforementioned a1), the jet solenoid valve SV1 must remain open for at least 3 minutes before it can be closed.

6. The control method for a multi-split heat pump unit with a flash evaporator according to claim 1, characterized in that, In b2), when the exhaust temperature of 45 < T < 50°C is maintained for 30 seconds, the jet solenoid valve SV1 maintains its current state.

7. The control method for a multi-split heat pump unit with a flash evaporator according to claim 1, characterized in that, In b2), when 35 < compressor operating frequency < 40 Hz is maintained for 30 s, the jet solenoid valve SV1 maintains its current state.

8. The control method for a multi-split heat pump unit with flash evaporator according to claim 1, characterized in that, In b2), when 28 < P high pressure < 34 bar and is maintained for 30 s, the jet solenoid valve SV1 maintains its current state.

9. A control method for a multi-split heat pump unit with a flash evaporator according to claim 1, characterized in that, In b2), when 10 < T exhaust superheat < 15°C for 30s, the jet solenoid valve SV1 maintains its current state.

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