Central flue system and control method thereof

Abstract

The central flue system comprises extractor hoods installed on different floors, each extractor hood comprises an oil smoke suction module, a compressor, a heat dissipation module and an indoor unit module, each oil smoke suction module comprises an oil smoke suction fan, and an air outlet of each oil smoke suction fan is communicated with a public flue through a smoke pipe; the heat dissipation module comprises a condenser and a heat dissipation fan, the indoor unit module comprises an evaporator and an indoor unit fan, a ventilation opening is formed in the volute annular wall of the oil smoke suction fan, and an air outlet of the heat dissipation fan can be in fluid communication with the interior of the volute through the ventilation opening. A pressure sensor used for detecting the back pressure of the public flue is installed at the smoke pipe outlet of each range hood, and the controller can receive output signals of the corresponding pressure sensor and correspondingly adjust the rotating speed of the cooling fan according to the received signals. The controller of the central flue system can automatically adjust the gear of the cooling fan according to the back pressure of the corresponding public smoke, the temperature of the condenser and whether the oil smoke sensor gives an alarm or not, and the intelligent degree is high.

Description

Technical Field

[0001] The invention relates to a central flue system, in particular to a central flue system and a control method thereof. Background Art

[0002] At present, the floors of newly built buildings in cities are generally getting higher and higher, and they are mainly decorated with fine engineering. Most high-rise residential buildings use indoor range hoods, smoke pipes, check valves and public flues to connect them, so that the fumes in the kitchen are discharged into the public flue through the indoor powered range hood through the smoke pipe. Since the outlet of the high-rise public flue is generally set at the top, the switching of the user's range hood will affect the outlet resistance of the system. The increase in the distance of the flue will lead to an increase in losses along the way. The exhaust of the range hood upstairs will increase the exhaust resistance downstairs, making the pressure distribution in the public flue extremely uneven. Generally, the exhaust effect is good on the upper floors, and the exhaust effect is poor on the lower floors due to high pressure. Especially during the peak cooking period, the exhaust effect on the lower floors is even worse. However, the cross-sectional area of ​​the public flue is generally defined by the building design specifications. In the case that the flue area cannot be increased, blindly increasing the air volume will lead to flue blockage and increase the flow rate and noise of the entire flue system.

[0003] Traditional range hoods generally only have weak and strong modes. Users on the 2nd floor often turn on the strong mode because the public flue resistance is large, and users on the 15th floor often turn on the strong mode because they are in the middle floor. However, compared with users on the 2nd floor, the public flue resistance of users on the 15th floor is much smaller. At this time, users on the 15th floor can use a mode lower than the strong mode, that is, to achieve the oil fume absorption effect and reduce the fan speed, reduce noise and have a better experience effect. For example, there is a central flue system, in which a pressure sensor is set at the outlet of the smoke pipe of each user. The pressure sensor detects the back pressure resistance of the public flue. In order to take into account both the oil fume absorption effect and the user's noise experience, a cruise mode is now set. Through the pressure sensor of each user on each floor, the public flue back pressure is sensed, and the corresponding speed is automatically adjusted. The speed is the lowest when the oil fume absorption effect is met. Taking a 30-story building as an example, the 1-10th floor can be set to the same mode, the 11-20th floor can be set to the same mode, and the 21-30th floor can be set to the same mode. Pressure sensors are placed on the 1st floor, 11th floor, and 21st floor respectively. For floors 1-10, the strong gear mode is adopted according to the worst user situation on the 1st floor. At this time, floors 1-10 all adopt the strong gear mode; for floors 11-20, the medium gear mode is adopted according to the worst user situation on the 11th floor. At this time, floors 11-20 all adopt the medium gear mode. Compared with the original users pressing the strong gear themselves, the noise is greatly reduced at this time; for floors 21-30, the weak gear mode is adopted according to the worst user situation on the 21st floor. At this time, floors 21-30 all adopt the weak gear mode. The control method of the above central flue system has obvious effects on noise reduction and improving the working efficiency of the range hood, and is generally applicable to central flue systems of various structures. However, for central flue systems with refrigeration range hoods installed on each floor, the control method of the above central flue system needs to be further improved. Summary of the invention

[0004] The first technical problem to be solved by the present invention is to provide a central flue system capable of intelligently adjusting the air volume of the cooling fan according to the size of the public flue back pressure in response to the above-mentioned existing technical status.

[0005] The second technical problem to be solved by the present invention is to provide a control method for the above-mentioned central flue system in view of the above-mentioned existing technical status.

[0006] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: the central flue system includes range hoods installed on different floors, the range hoods include a fume extraction module, a compressor, a heat dissipation module and an indoor unit module, the fume extraction module includes a fume extraction fan, the air outlet of the fume extraction fan is connected with the common flue through a smoke pipe, the heat dissipation module includes a condenser and a heat dissipation fan, the indoor unit module includes an evaporator and an indoor unit fan, the compressor, condenser and evaporator are connected through a refrigerant pipeline, and is characterized in that: a vent is opened on the volute ring wall of the range hood, the air outlet of the heat dissipation fan can be fluidly connected with the inside of the volute through the vent, a pressure sensor for detecting the back pressure of the common flue is installed at the smoke pipe outlet of each range hood, and each range hood also includes a controller, which can receive the output signal of the corresponding pressure sensor and adjust the rotation speed of the heat dissipation fan accordingly according to the received signal.

[0007] Preferably, the controller can adjust the rotation speeds of the heat dissipation fan and the range fumes suction fan accordingly according to the output signal received from the pressure sensor.

[0008] In order to make the central flue system more intelligent, it also includes a temperature sensor and an oil fume sensor. The temperature sensor is installed on the surface of the condenser and is used to detect the condenser temperature. The oil fume sensor is installed at the air outlet of the heat dissipation fan. The controller can receive the output signals of the temperature sensor and the oil fume sensor and adjust the speed of the heat dissipation fan and the oil fume suction fan according to the received signals. In this way, the air volume of the heat dissipation fan and the oil fume suction fan can be adjusted accordingly according to the temperature of the condenser and whether there is oil fume backflow into the heat dissipation fan, which has a high degree of intelligence.

[0009] In order to improve the air intake effect, the ventilation opening is arranged at the front section of the volute ring wall and close to the root of the volute tongue of the range fumes exhaust fan.

[0010] In order to effectively guide the wind blown out by the heat dissipation fan into the interior of the range fumes suction fan, an air guide cover is installed at the ventilation opening.

[0011] In order to fully utilize the condensed water from the air conditioner, a water receiving box is installed inside the range hood to collect the condensed water condensed on the surface of the evaporator. The condensed water in the water receiving box can be transported to the condenser and / or the inside of the heat dissipation fan. The condensed water can be used to cool the condenser, or it can be transported to the inside of the heat dissipation fan. The condensed water enters the inside of the heat dissipation fan, which cools the heat dissipation fan on the one hand, and enters the range hood fan through the air outlet of the heat dissipation fan on the other hand, and is finally discharged to the outside.

[0012] The range fumes exhaust fan and the heat dissipation fan can be arranged in a variety of ways. Preferably, the range fumes exhaust fan and the heat dissipation fan are centrifugal fans, and the central axis of the impeller of the range fumes exhaust fan is parallel to the central axis of the impeller of the heat dissipation fan.

[0013] In order to allow the wind blown out by the heat dissipation fan to smoothly enter the interior of the range fumes suction fan, the heat dissipation fan is arranged above the range fumes suction fan, and the air outlet of the heat dissipation fan faces the ventilation port.

[0014] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a control method for a central flue system, characterized in that: the control method divides the floors into low-floor intervals, middle-floor intervals and high-floor intervals, and adjusts the gears of the heat dissipation fan and the range fumes exhaust fan according to the back pressure of the public flue corresponding to the lowest floor in different floor intervals, and adjusts the gear of the heat dissipation fan according to the temperature of the condenser, and increases the gear of the heat dissipation fan when the range fumes sensor is in an alarm state.

[0015] Further preferably, the control method of the central flue system comprises the following steps:

[0016] S1, the range hood enters the air conditioning mode;

[0017] S2, respectively determining whether the public flue back pressure P corresponding to the range hoods on the lowest floor in the low-floor interval, the middle-floor interval, and the high-floor interval satisfies P>P2;

[0018] If yes, then go to step S3,

[0019] If not, proceed to step S4;

[0020] S3, the range hood fans of the corresponding floor interval are turned on at a high gear, the corresponding heat dissipation fans are turned on at a low gear, and the indoor fans are turned on according to the gear mode of the air conditioner turned on by the user, and then the process proceeds to step S7;

[0021] S4, determining whether the public flue back pressure P of the range hoods on the lowest floor among the low-floor interval, the middle-floor interval and the high-floor interval satisfies P1<P≤P2;

[0022] If yes, then go to step S5,

[0023] If not, proceed to step S6;

[0024] S5, the range hood fans of the corresponding floor interval are turned on at mid-gear, the corresponding heat dissipation fans are turned on at mid-gear, and the indoor fans are turned on according to the gear mode of the air conditioner turned on by the user, and then the process proceeds to step S8;

[0025] S6, the range hood fans of the corresponding floor interval are turned on at a low gear, the corresponding heat dissipation fans are turned on at a high gear, and the indoor fans are turned on according to the gear mode of the air conditioner turned on by the user, and then the process proceeds to step S9;

[0026] S7, determine whether the condenser temperature T satisfies T<T1,

[0027] If T<T1 is satisfied, the gear of the cooling fan is lowered, and then it is determined whether the condenser temperature T satisfies T>T2, or whether the oil fume sensor alarms. If so, the gear of the cooling fan is increased, if not, the gear of the cooling fan is lowered, wherein T2>T1;

[0028] If T<T1 is not satisfied, return to step S3;

[0029] S8, determine whether the condenser temperature T satisfies T<T1,

[0030] If T<T1 is satisfied, the gear of the cooling fan is lowered, and then it is determined whether the condenser temperature T satisfies T>T2, or whether the oil fume sensor alarms. If so, the gear of the cooling fan is increased, if not, the gear of the cooling fan is lowered;

[0031] If T<T1 is not satisfied, return to step S5;

[0032] S9, determine whether the condenser temperature T satisfies T<T1,

[0033] If T<T1 is satisfied, the gear of the cooling fan is lowered, and then it is determined whether the condenser temperature T satisfies T>T2, or whether the oil fume sensor alarms. If so, the gear of the cooling fan is increased, if not, the gear of the cooling fan is lowered;

[0034] If T<T1 is not satisfied, the process returns to step S6.

[0035] Compared with the prior art, the advantages of the present invention are: the central flue system is equipped with a refrigeration type range hood on each different floor, the refrigeration type range hood includes a fume extraction module, a compressor, a heat dissipation module and an internal unit module, the air outlet of the heat dissipation fan can be fluidly connected with the inside of the volute through the vents on the volute ring wall, the back pressure of the range hood on each floor is detected by a pressure sensor, the controller can receive the output signal of the corresponding pressure sensor and adjust the speed of the heat dissipation fan accordingly according to the received signal, that is, the speed of the heat dissipation fan can be adaptively adjusted according to the back pressure, the control method can also automatically adjust the gear of the heat dissipation fan according to the temperature of the condenser and whether the fume sensor alarms, and the degree of intelligence is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of a range hood according to an embodiment of the present invention;

[0037] Figure 2 for Figure 1 A structural cross-sectional view of the range hood shown;

[0038] Figure 3 A schematic structural diagram of a central flue system according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the connection of the air conditioning components of the range hood according to an embodiment of the present invention;

[0040] Figure 5 This is a flow chart of a control method for a central flue system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below with reference to the accompanying drawings.

[0042] like Figures 1 to 4 As shown, the central flue system of this embodiment includes a range hood 1 installed on different floors. The range hood 1 is a refrigeration range hood, including a range hood module 11, a compressor 12, a heat dissipation module 13 and an indoor unit module 14. The range hood module 11 includes a range hood fan 111, and the air outlet of the range hood fan 111 is connected to the public flue 2 through a smoke pipe. The heat dissipation module 13 includes a condenser 131 and a heat dissipation fan 132, and the indoor unit module 14 includes an evaporator 141 and an indoor unit fan 142. The compressor 12, the condenser 131 and the evaporator 141 are connected through a refrigerant pipeline 15. The compressor 12, the condenser 131 and the evaporator 141 constitute an air conditioning component, and its working principle is the same as that of the existing air conditioning principle, which will not be described in detail here.

[0043] A vent 113 is provided on the volute ring wall 112 of the range fume extractor fan 111, and the air outlet of the heat dissipation fan 132 can be fluidly connected with the interior of the volute through the vent 113. The vent 113 of this embodiment is provided at the front section of the volute ring wall 112 and close to the root of the volute tongue 114 of the range fume extractor fan 111, and an air guide cover 115 is installed at the vent 113. The range fume extractor fan 111 and the heat dissipation fan 132 are both centrifugal fans, and the central axis of the impeller of the range fume extractor fan 111 is parallel to the central axis of the impeller of the heat dissipation fan 132. The heat dissipation fan 132 is arranged above the range fume extractor fan 111, and the air outlet of the heat dissipation fan 132 faces the vent 113. The heat dissipation fan 132 is used to dissipate heat from the condenser 131, and the hot air blown out by the heat dissipation fan 132 enters the interior of the range fume extractor fan 111 through the vent 113.

[0044] A water receiving box 18 is installed inside the range hood 1 for collecting condensed water condensed on the surface of the evaporator 141. The condensed water in the water receiving box 18 can be transported to the condenser 131 and / or the inside of the heat dissipation fan 132. The condensed water can be used to cool the condenser 131, and can also be transported to the inside of the heat dissipation fan 132. The condensed water enters the inside of the heat dissipation fan 132, which cools the heat dissipation fan 132 on the one hand, and enters the range hood fan 111 through the air outlet of the heat dissipation fan 132 on the other hand, and is finally discharged to the outside.

[0045] A pressure sensor for detecting the back pressure of the common flue 2 is installed at the smoke pipe outlet of each range hood 1. Each range hood 1 has a controller, which can receive the output signal of the corresponding pressure sensor and adjust the speed of the heat dissipation fan 132 and the range hood fan 111 accordingly according to the received signal. In the case of a large back pressure, the speed of the range hood fan 111 is usually increased, and the speed of the heat dissipation fan 132 is reduced.

[0046] In addition, a temperature sensor 16 for detecting the temperature of the condenser 131 is installed on the surface of the condenser 131, and an oil fume sensor 17 is installed at the air outlet of the heat dissipation fan 132. When the oil fume in the oil fume suction fan 111 flows back into the heat dissipation fan 132 through the vent 113, the oil fume sensor 17 sends an alarm signal to the controller. The controller can receive the output signals of the temperature sensor 16 and the oil fume sensor 17 and adjust the rotation speeds of the heat dissipation fan 132 and the oil fume suction fan 111 according to the received signals.

[0047] like Figure 5 As shown, the control method of the central flue system of this embodiment divides the floors into low-floor intervals, middle-floor intervals and high-floor intervals, and adjusts the gears of the heat dissipation fan 132 and the oil fume suction fan 111 according to the back pressure of the public flue 2 corresponding to the lowest floor in different floor intervals, and adjusts the gear of the heat dissipation fan 132 according to the temperature of the condenser 131, and increases the gear of the heat dissipation fan 132 when the oil fume sensor 17 is in an alarm state. Specifically, it includes the following steps:

[0048] S1, range hood 1 enters air conditioning mode;

[0049] S2, respectively determining whether the back pressure P of the public flue 2 corresponding to the range hood 1 on the lowest floor in the low-floor interval, the middle-floor interval, and the high-floor interval satisfies P>P2;

[0050] If yes, then go to step S3,

[0051] If not, proceed to step S4;

[0052] S3, the range hood fan 111 of the corresponding floor area is turned on at a high gear, the corresponding heat dissipation fan 132 is turned on at a low gear, and the indoor fan 142 is turned on according to the gear mode of the air conditioner turned on by the user, and then enters step S7;

[0053] S4, determining whether the back pressure P of the common flue 2 of the range hood 1 on the lowest floor among the low-floor interval, the middle-floor interval and the high-floor interval satisfies P1<P≤P2;

[0054] If yes, then go to step S5,

[0055] If not, proceed to step S6;

[0056] S5, the range hood fan 111 of the corresponding floor area is turned on at a medium gear, the corresponding heat dissipation fan 132 is turned on at a medium gear, and the indoor fan 142 is turned on according to the gear mode of the air conditioner turned on by the user, and then enters step S8;

[0057] S6, the range hood fan 111 of the corresponding floor area is turned on at a low gear, the corresponding heat dissipation fan 132 is turned on at a high gear, and the indoor fan 142 is turned on according to the gear mode of the air conditioner turned on by the user, and then enters step S9;

[0058] S7, determine whether the temperature T of the condenser 131 satisfies T<T1,

[0059] If T<T1 is satisfied, the gear of the cooling fan 132 is reduced, and then it is determined whether the temperature T of the condenser 131 satisfies T>T2, or it is determined whether the oil smoke sensor 17 alarms. If so, the gear of the cooling fan 132 is increased, if not, the gear of the cooling fan 132 is reduced, wherein T2>T1;

[0060] If T<T1 is not satisfied, return to step S3;

[0061] S8, determine whether the temperature T of the condenser 131 satisfies T<T1,

[0062] If T<T1 is satisfied, the gear of the cooling fan 132 is reduced, and then it is determined whether the temperature T of the condenser 131 satisfies T>T2, or it is determined whether the oil fume sensor 17 alarms. If so, the gear of the cooling fan 132 is increased, if not, the gear of the cooling fan 132 is reduced;

[0063] If T<T1 is not satisfied, return to step S5;

[0064] S9, determine whether the temperature T of the condenser 131 satisfies T<T1,

[0065] If T<T1 is satisfied, the gear of the cooling fan 132 is reduced, and then it is determined whether the temperature T of the condenser 131 satisfies T>T2, or it is determined whether the oil fume sensor 17 alarms. If so, the gear of the cooling fan 132 is increased, if not, the gear of the cooling fan 132 is reduced;

[0066] If T<T1 is not satisfied, the process returns to step S6.

[0067] In this embodiment, it is assumed that T1 = 60°C and T2 = 70°C.

[0068] Take a 30-story building as an example, with 1-10 floors as the low-rise interval, 11-20 floors as the middle-rise interval, and 21-30 floors as the high-rise interval. For floors 21-30, based on the worst users on the 21st floor, the weak gear mode is adopted when the machine is turned on. At this time, floors 21-30 are all in the weak gear mode, and the cooling fan is turned on at the strong gear; for floors 11-20, based on the worst users on the 11th floor, the medium gear mode is adopted. At this time, floors 11-20 are all in the medium gear mode, and the cooling fan is turned on at the medium gear. Compared with the original users pressing the strong gear by themselves, the noise is greatly reduced at this time; for floors 1-10, based on the worst users on the 1st floor, the strong gear mode is adopted. At this time, floors 1-10 are all in the strong gear mode, and the cooling fan is turned on at the weak gear mode.

Claims

1. A central flue system, comprising a range hood (1) installed on different floors, the range hood (1) comprising a fume extraction module (11), a compressor (12), a heat dissipation module (13) and an indoor unit module (14), the fume extraction module (11) comprising a fume extraction fan (111), the air outlet of the fume extraction fan (111) being connected to a common flue (2) through a flue pipe, the heat dissipation module (13) comprising a condenser (131) and a heat dissipation fan (132), the indoor unit module (14) comprising an evaporator (141) and an indoor unit fan (142), the compressor (12), the condenser (131) and the evaporator (141) being connected through a refrigerant pipeline (15), characterized in that: A vent (113) is provided on the volute ring wall (112) of the range hood fan (111); an air outlet of the heat dissipation fan (132) can be fluidically connected to the interior of the volute through the vent (113); a pressure sensor for detecting the back pressure of the common flue (2) is installed at the smoke pipe outlet of each range hood (1); each range hood (1) also includes a controller, which can receive an output signal of a corresponding pressure sensor and adjust the rotation speed of the heat dissipation fan (132) accordingly according to the received signal.

2. The central flue system according to claim 1, characterized in that: The controller can adjust the rotation speeds of the heat dissipation fan (132) and the range fumes suction fan (111) accordingly according to the output signal received from the pressure sensor.

3. The central flue system according to claim 1, characterized in that: It also includes a temperature sensor (16) and an oil fume sensor (17), wherein the temperature sensor (16) is installed on the surface of the condenser (131) and is used to detect the temperature of the condenser (131), and the oil fume sensor (17) is installed at the air outlet of the heat dissipation fan (132). The controller is capable of receiving output signals of the temperature sensor (16) and the oil fume sensor (17) and adjusting the rotation speeds of the heat dissipation fan (132) and the oil fume suction fan (111) according to the received signals.

4. The central flue system according to claim 1, characterized in that: The ventilation opening (113) is arranged at the front section of the volute ring wall (112) and is close to the root of the volute tongue (114) of the range fumes exhaust fan (111).

5. The central flue system according to claim 1, characterized in that: An air guide cover plate (115) is installed on the ventilation opening (113).

6. The central flue system according to claim 1, characterized in that: A water receiving box (18) is installed inside the range hood (1) for collecting condensed water condensed on the surface of the evaporator (141), and the condensed water in the water receiving box (18) can be transported to the condenser (131) and / or the inside of the heat dissipation fan (132).

7. The central flue system according to claim 1, characterized in that: The fume extraction fan (111) and the heat dissipation fan (132) are both centrifugal fans, and the central axis of the impeller of the fume extraction fan (111) and the central axis of the impeller of the heat dissipation fan (132) are parallel to each other.

8. The central flue system according to claim 1, characterized in that: The heat dissipation fan (132) is arranged above the range fumes suction fan (111), and the air outlet of the heat dissipation fan (132) faces the ventilation port (113).

9. A method for controlling a central flue system, characterized in that: The control method is applied to the central flue system described in claim 3. The control method divides the floors into a low floor interval, a middle floor interval and a high floor interval, and adjusts the gears of the heat dissipation fan (132) and the oil fume suction fan (111) according to the back pressure of the public flue (2) corresponding to the lowest floor in different floor intervals, and adjusts the gear of the heat dissipation fan (132) according to the temperature of the condenser (131), and increases the gear of the heat dissipation fan (132) when the oil fume sensor (17) is in an alarm state.

10. The control method of the central flue system according to claim 9, characterized in that The control method comprises the following steps: S1, the range hood (1) enters the air conditioning mode; S2, respectively judging whether the back pressure P of the public flue (2) corresponding to the range hood (1) at the lowest level in the low-floor interval, the middle-floor interval and the high-floor interval satisfies P>P2; If yes, then go to step S3, If not, proceed to step S4; S3, the range hood fan (111) of the corresponding floor area is turned on at a high gear, the corresponding heat dissipation fan (132) is turned on at a low gear, and the indoor fan (142) is turned on according to the gear mode of the air conditioner turned on by the user, and then the process proceeds to step S7; S4, determining whether the back pressure P of the common flue (2) of the range hood (1) on the lowest floor among the low-floor interval, the middle-floor interval and the high-floor interval satisfies P1<P≤P2; If yes, go to step S5, If not, proceed to step S6; S5, the range hood fan (111) of the corresponding floor area is turned on at a medium gear, the corresponding heat dissipation fan (132) is turned on at a medium gear, and the indoor fan (142) is turned on according to the gear mode of the air conditioner turned on by the user, and then the process proceeds to step S8; S6, the range hood fan (111) of the corresponding floor area is turned on at a weak gear, the corresponding heat dissipation fan (132) is turned on at a strong gear, and the indoor fan (142) is turned on according to the gear mode of the air conditioner turned on by the user, and then the process proceeds to step S9; S7, judging whether the temperature T of the condenser (131) satisfies T<T1, If T<T1 is satisfied, the gear of the heat dissipation fan (132) is lowered, and then it is determined whether the temperature T of the condenser (131) satisfies T>T2, or it is determined whether the oil smoke sensor (17) alarms. If so, the gear of the heat dissipation fan (132) is increased, and if not, the gear of the heat dissipation fan (132) is lowered, wherein T2>T1; If T<T1 is not satisfied, return to step S3; S8, judging whether the temperature T of the condenser (131) satisfies T<T1, If T<T1 is satisfied, the gear of the cooling fan (132) is lowered, and then it is determined whether the temperature T of the condenser (131) satisfies T>T2, or it is determined whether the oil smoke sensor (17) alarms. If so, the gear of the cooling fan (132) is increased; if not, the gear of the cooling fan (132) is lowered; If T<T1 is not satisfied, return to step S5; S9, judging whether the temperature T of the condenser (131) satisfies T<T1, If T<T1 is satisfied, the gear of the cooling fan (132) is lowered, and then it is determined whether the temperature T of the condenser (131) satisfies T>T2, or it is determined whether the oil smoke sensor (17) alarms. If so, the gear of the cooling fan (132) is increased; if not, the gear of the cooling fan (132) is lowered; If T<T1 is not satisfied, the process returns to step S6.

Images