CN204787419U - Air conditioner - Google Patents

Abstract

The utility model relates to an air conditioner, which comprises a compressor, an outdoor heat exchanger and an indoor heat exchanger communicated through pipelines, and also includes a first four-way valve and a second four-way valve, the first four-way valve includes an a1 port, Port b1, port c1, and port d1, the second four-way valve includes port a2, port b2, port c2, and port d2, the outlet of the compressor is connected to port a1 through a pipeline, the inlet of the compressor is connected to port c1 through a pipeline, outdoor The two ends of the heat exchanger are respectively connected to the b2 port and the d2 port through the pipeline, the two ends of the indoor heat exchanger are respectively connected to the b1 port and the c2 port through the pipeline, and the d1 port is connected to the a2 port through the pipeline. The utility model realizes the switching between the heating mode and the defrosting mode by controlling the power-on and power-off of the two four-way valves, thereby speeding up the defrosting speed, improving the defrosting effect, and avoiding large fluctuations in room temperature.

Description

an air conditioner

technical field

The utility model relates to an air conditioner, in particular to a cooling and heating type air conditioner which improves the defrosting effect, and belongs to the technical field of air conditioners.

Background technique

When the traditional cooling and heating type electric auxiliary heating air conditioner is heating, if the external environment temperature is low, frost will form on the outdoor heat exchanger (also called condenser) after running for a period of time, thereby reducing the heat exchange capacity of the heat exchanger. affect the normal operation of the air conditioner. At this time, the air conditioner will enter the defrosting mode. During defrosting, the refrigerant flows in the cooling direction. After defrosting, the air conditioner can work normally. The defrosting time generally takes about 10 minutes. During the defrosting process, the air conditioner will not heat the room. On the contrary, the temperature of the indoor evaporator will be greatly reduced to below -20°C. Especially in low-temperature and high-humidity environments, defrosting will occur more frequently, resulting in constant fluctuations in room temperature and affecting user comfort.

In order to overcome the above-mentioned shortcomings of the reverse defrosting method, a bypass defrosting method also appeared in the prior art, also known as an uninterrupted heating defrosting method. As disclosed in the following prior patents, the patent application number is 200910134993.0, and the patent name is a defroster for an air conditioner. The solution is to bypass a flow path on the pipeline between the exhaust port of the compressor and the four-way valve to connect between the liquid outlet of the condenser and the throttling component, and connect a solenoid valve in series on the flow path. When the control system judges that defrosting is needed, the solenoid valve on the direct bypass flow path is opened to allow most of the high-temperature gaseous refrigerant to flow directly to the condenser for defrosting. When the exhaust gas temperature drops to a certain temperature, the solenoid valve on the bypass flow path is closed, the four-way valve is powered off, and the system defrosts according to the refrigeration cycle (also known as forward defrosting). This defrosting method can speed up the defrosting of the system when the frost layer is small, but if the frost layer is thick, the exhaust temperature of the compressor will drop significantly after several cycles, resulting in prolonged defrosting time.

The content disclosed in the previous patent, the patent application number is 200910020567.4, and the patent name is a heating and cooling type inverter air conditioner and its defrosting method. The scheme is aimed at the defrosting structure and defrosting method of the frequency conversion compressor used in the air conditioner. The outdoor unit of the air conditioner bypasses the primary circuit at the exhaust pipe of the compressor to between the outlet pipe of the condenser and the electronic expansion valve. During reverse defrosting, part of the refrigerant flows directly to the condenser for defrosting through the bypass circuit, and part of the refrigerant flows to the condenser for defrosting after being heated in the room. In the process of reverse defrosting, the indoor electric heating and indoor fan work. If the reverse defrosting is not clean, the system turns into a refrigeration cycle defrosting, and resumes normal heating after the defrosting is complete. In this solution, the indoor temperature fluctuates due to part of the refrigerant passing through the room to absorb heat during heating, although the heating is assisted by turning on the electric heater. If the heat absorbed by the refrigerant is close to the heat assisted by the electric heater, it will easily cause fluctuations in the indoor temperature. At the same time, the diversion of the refrigerant is not conducive to the rapid defrosting of the condenser, resulting in prolonged defrosting time.

Utility model content

The utility model aims at the above-mentioned shortcomings and deficiencies in the prior art, and provides an air conditioner with simple structure and convenient operation, so as to improve the defrosting efficiency of the air conditioner.

The technical solution of the utility model for solving the above-mentioned technical problems is as follows: an air conditioner, including a compressor, an outdoor heat exchanger and an indoor heat exchanger communicated through pipelines, and also includes a first four-way valve and a second four-way valve. The first four-way valve includes a1 port, b1 port, c1 port, and d1 port, the second four-way valve includes a2 port, b2 port, c2 port, and d2 port, and the outlet of the compressor is connected to the a1 port through a pipeline The inlet of the compressor is connected to port c1 through pipes, the two ends of the outdoor heat exchanger are connected to port b2 and port d2 through pipes, and the two ends of the indoor heat exchanger are connected to port b1 and port d2 through pipes respectively. Port c2, port d1 and port a2 are connected through pipelines; when the first four-way valve is powered on, port a1 is connected to port b1, and port c1 is connected to port d1; when the first four-way valve is powered off, a1 The port is connected to the d1 port, and the b1 port is connected to the c1 port; when the second four-way valve is energized, the a2 port is connected to the d2 port, and the b2 port is connected to the c2 port; the second four-way valve is de-energized When , the a2 port and the b2 port are conducted, and the c2 port and the d2 port are conducted.

The air conditioner described in the utility model is a cooling and heating type air conditioner, which can be a wall-mounted air conditioner or a floor-standing air conditioner.

On the basis of the above technical solutions, the utility model can also be improved as follows.

Further, a throttling component is provided on the pipeline between the c2 port and the indoor heat exchanger, and the throttling element is a capillary tube or an electronic expansion valve.

The beneficial effect of adopting the above-mentioned further scheme is that the throttling part has the function of throttling and reducing the pressure of the refrigerant in the pipeline. Commonly used in air conditioners are capillary tubes with a diameter of about 1.0-3.5 mm or can automatically circulate the refrigerant. An electronic expansion valve whose volume is controlled to a certain value.

Further, an outdoor fan is arranged at the outdoor heat exchanger, and the outdoor fan introduces wind into the outdoor heat exchanger; an indoor fan is arranged at the indoor heat exchanger, and the leeward side of the indoor heat exchanger is arranged There is an indoor electric heater that is turned on at least during the defrosting process of the air conditioner. When the indoor fan rotates forward, the wind is first introduced into the indoor heat exchanger and then passes through the indoor electric heater. When the indoor fan is reversed, the wind is First pass through the indoor electric heater and then introduce the indoor heat exchanger.

The beneficial effect of adopting the above further solution is that the specific positions of the outdoor fan and the indoor fan are not limited, as long as the wind can be induced, the outdoor fan is to introduce the wind into the outdoor heat exchanger, and the indoor fan needs to be connected with the indoor heat exchanger and the indoor fan. The position of the indoor electric heater is coordinated, and different air induction effects can be achieved through forward rotation and reverse rotation.

The utility model also relates to a method for defrosting the above-mentioned air conditioner, comprising the following steps:

Step 1: When the air conditioner is in heating mode, the compressor runs normally, the first four-way valve is powered on, the second four-way valve is powered off, the outdoor fan is running, and the indoor fan is running forward;

Step 2: When the system of the air conditioner determines that the defrosting condition is reached (that is, when the outdoor heat exchanger is frosted to a certain extent, and the electric control board of the air conditioner detects that the defrosting condition is reached), the compressor stops or the frequency is reduced, and the outdoor The fan stops, the first four-way valve is powered off, and the second four-way valve is powered on;

Step 3: After the set time t1, the indoor electric heater is in the working state, the indoor fan rotates in the opposite direction, and the wind speed is in the breeze state;

Step 4: After the set time t2, the compressor starts or increases in frequency, and enters the defrosting mode;

Step 5: When the system of the air conditioner judges that the defrost exit condition is met, the defrost mode is exited, the compressor is stopped or the frequency is reduced, the outdoor fan is turned on, the first four-way valve is powered on, and the second four-way valve is powered off;

Step 6: After the set time t3, the compressor starts or increases in frequency, the outdoor fan runs, the indoor fan rotates towards the breeze, and the indoor electric heater continues to work;

Step 7: Check the temperature of the coil of the indoor unit. If it reaches Tx, the indoor fan will run at the speed set before defrosting. If it reaches Ty, the indoor electric heater will be turned off, and it will return to the heating mode.

The general method in the prior art is used to determine the defrosting condition of the air conditioner system. In the field of air conditioner technology, there are many defrosting conditions for the air conditioner, but according to the different environmental conditions of the air conditioner, the most suitable defrosting condition Each is different, the following are examples of several defrosting trigger conditions commonly used in domestic general air conditioners:

The first entry condition: 1. After entering the heating mode or defrosting mode for about 5 minutes, judge according to the maximum difference between the outdoor unit coil temperature and the indoor temperature, and the judgment time is 3 minutes. 2. When the difference between the indoor unit coil temperature and the indoor temperature decreases by more than 5 degrees and lasts for more than 3 minutes. 3. Ensure that the accumulative working time of the compressor exceeds 45 minutes. 4. The temperature of the indoor unit coil is less than 48 degrees. If these four conditions are met at the same time, it will start to defrost.

The second condition: the accumulative running time of the compressor exceeds 45 minutes, and the continuous running time exceeds 20 minutes, and the coil temperature of the indoor unit is lower than the indoor temperature of 16 degrees for 5 minutes, then enters the defrosting state.

The third condition: the compressor has been running for more than 3 hours and has been running continuously for more than 20 minutes, and the coil temperature of the indoor unit is lower than the indoor temperature of 16 degrees for 5 minutes, then it will enter the defrosting state.

The fourth condition: the outdoor fan enters the overload protection and the outdoor fan stops, and the continuous running time of the outdoor fan is more than 10 minutes when the outdoor fan is started next time, and the accumulated running time of the compressor exceeds 45 minutes or the indoor unit coil temperature is guaranteed to run continuously for 20 minutes If it is less than 48 degrees, it will enter the defrosting state.

The fifth condition: if the outdoor fan stops running for two hours and the defrosting has not started, the defrosting will be forced.

Further, in step 1, the heating mode of the air conditioner of the present invention is: after the refrigerant is discharged from the outlet of the compressor, it flows to the indoor heat exchanger through the a1 port and the b1 port of the first four-way valve, and then passes through the throttling component and The c2 port and d2 port of the second four-way valve flow to the outdoor heat exchanger for evaporation, flow out through the b2 port and a2 port of the second four-way valve, and flow from the compressor through the d1 port and c1 port of the first four-way valve inlet flow back to the compressor.

Further, in step 4, the defrosting mode of the air conditioner of the present invention is: the high-temperature and high-pressure gaseous refrigerant is discharged from the outlet of the compressor, flows out through the a1 port and the d1 port of the first four-way valve, and passes through the port of the second four-way valve. Port a2 and port d2 enter the defrost from the lower part of the outdoor heat exchanger, then flow out from the upper part of the outdoor heat exchanger, pass through the b2 port and c2 port of the second four-way valve, and flow through the throttling part to the indoor heat exchanger. The low-temperature refrigerant in the heater is heated by the indoor electric heater and flows back to the compressor from the compressor inlet.

The beneficial effect of adopting the above further scheme is that the utility model realizes the conversion between the heating mode and the defrosting mode by controlling the power-on and power-off of the two four-way valves, which is different from other pipelines in the background technology. The new type is reversed in the original pipeline, through the cooperation of the compressor, outdoor fan, indoor fan and indoor electric heater and two four-way valves to realize the switching of the air conditioner mode. Convenient and quick to adjust.

Further, in step 5, the condition for exiting defrosting is that the accumulative defrosting time reaches the set time tx or the coil temperature of the outdoor unit ≥ the set temperature Ts or the compressor current reaches or exceeds I _DEFROST for n seconds. Specifically, the conditions for exiting defrosting are that the cumulative defrosting time reaches the set time of 10 minutes or the outdoor unit coil temperature is greater than or equal to the set temperature of 15°C or the compressor current reaches or exceeds I _DEFROST for 1 second continuously, where the current value I _DEFROST is determined by The air conditioner model is determined, and the random model is different.

In the defrosting method of the air conditioner of the present utility model, each specific preferred numerical range is: t1 is 3-8 seconds, t2 is 10-40 seconds, t3 is 10-40 seconds, Tx is 30-35 ° C, Ty is 52-56°C; the optimal value of the above values is: t1 is 5 seconds, t2 is 15 seconds, t3 is 15 seconds, Tx is 32°C, and Ty is 54°C.

The beneficial effects of the utility model are: compared with the prior art, the utility model adds the second four-way valve, which is opened during defrosting, and the high-temperature refrigerant flows in from the lower part of the outdoor heat exchanger with serious frosting and flows out from the upper part, which is beneficial defrost. At the same time, when defrosting, the indoor fan is reversed, and the indoor electric heater is turned on. The low-temperature refrigerant in the defrosting process is heated by the indoor electric heater and flows back to the compressor. The exhaust temperature of the compressor increases, thereby speeding up the defrosting speed and improving It improves the defrosting effect and avoids large fluctuations in room temperature.

Description of drawings

Fig. 1 is a system structure diagram of an embodiment of defrosting of the air conditioner of the present invention.

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Compressor, 2. First four-way valve, 3. Second four-way valve, 4. Outdoor heat exchanger, 5. Outdoor fan, 6. Throttling parts, 7. Indoor fan, 8. Indoor heat exchanger , 9, indoor electric heater.

Detailed ways

The principles and features of the present utility model are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the utility model, and are not used to limit the scope of the utility model.

The utility model relates to an air conditioner, which includes a compressor 1, an outdoor heat exchanger 4 and an indoor heat exchanger 8 communicated through pipelines, and also includes a first four-way valve 2 and a second four-way valve 3. The first The four-way valve 2 includes a1 port, b1 port, c1 port and d1 port, the second four-way valve 3 includes a2 port, b2 port, c2 port and d2 port, and the outlet of the compressor 1 is connected to the a1 port through a pipeline The inlet of the compressor 1 is communicated with the c1 port through a pipeline, the two ends of the outdoor heat exchanger 4 are respectively connected with the b2 port and the d2 port through a pipeline, and the two ends of the indoor heat exchanger 8 are respectively connected with a pipeline Port b1 and port c2, port d1 and port a2 are communicated through pipelines; when the first four-way valve 2 is energized, port a1 is connected to port b1, and port c1 is connected to port d1; the first four-way valve 2 When the power is off, the a1 port is connected to the d1 port, and the b1 port is connected to the c1 port; when the second four-way valve 3 is powered on, the a2 port is connected to the d2 port, and the b2 port is connected to the c2 port; When the two four-way valve 3 is de-energized, the a2 port is connected to the b2 port, and the c2 port is connected to the d2 port.

The air conditioner described in the utility model is a cooling and heating type air conditioner, which can be a wall-mounted air conditioner or a floor-standing air conditioner.

Preferably, a throttling component 6 is provided on the pipeline between the c2 port and the indoor heat exchanger 8, and the throttling component 6 is a capillary tube or an electronic expansion valve. The throttling part 6 has the effect of throttling and lowering the pressure of the refrigerant in the pipeline. Commonly used in air conditioners are capillary tubes with a diameter of about 1.0-3.5mm or electronic devices that can automatically control the circulation of the refrigerant to a certain value. Expansion valve.

Preferably, an outdoor fan 5 is provided at the outdoor heat exchanger 4, and the outdoor fan 5 introduces wind into the outdoor heat exchanger 4; an indoor fan 7 is provided at the indoor heat exchanger 8, and the indoor The leeward side of the heat exchanger 8 is provided with an indoor electric heater 9 that is turned on at least during the defrosting process of the air conditioner. When the indoor fan 7 is rotating forward, the wind is first introduced into the indoor heat exchanger 8 and then heated by the indoor electric heater. When the indoor fan 7 is reversed, the wind will first pass through the indoor electric heater 9 and then be introduced into the indoor heat exchanger 8.

The specific positions of the outdoor fan 5 and the indoor fan 7 are not limited, as long as the air can be induced. The positions of the heaters 9 match each other, and through forward rotation and reverse rotation, different air induction effects are realized.

The utility model also relates to a method for defrosting the above-mentioned air conditioner, comprising the following steps:

Step 1: When the air conditioner is in the heating mode, the compressor 1 is running normally, the first four-way valve 2 is powered on, the second four-way valve 3 is powered off, the outdoor fan 5 is running, and the indoor fan 7 is running forward;

Step 2: When the system of the air conditioner determines that the defrosting condition is reached (that is, when the outdoor heat exchanger is frosted to a certain extent, and the electric control board of the air conditioner detects that the defrosting condition is reached), the compressor 1 stops or reduces the frequency, The outdoor fan 5 stops, the first four-way valve 2 is powered off, and the second four-way valve 3 is powered on;

Step 3: After the set time t1, the indoor electric heater 9 is in the working state, the indoor fan 7 rotates in the opposite direction, and the wind speed is in the breeze state;

Step 4: After the set time t2, the compressor 1 starts or increases in frequency, and enters the defrosting mode;

Step 5: When the system of the air conditioner judges that the defrosting condition is met, the defrosting mode is exited, the compressor 1 is stopped or the frequency is reduced, the outdoor fan 5 is turned on, the first four-way valve 2 is powered on, and the second four-way valve 3 is powered off ;

Step 6: After the set time t3, the compressor 1 is started or the frequency is increased, the outdoor fan 5 is running, the indoor fan 7 is turning towards the breeze, and the indoor electric heater 9 continues to work;

Step 7: Detect the temperature of the coil of the indoor unit. If it reaches Tx, the indoor fan 7 runs at the speed set before defrosting. If it reaches Ty, the indoor electric heater 9 is turned off, and returns to the heating mode.

The general method in the prior art is used to determine the defrosting condition of the air conditioner system. In the field of air conditioner technology, there are many defrosting conditions for the air conditioner, but according to the different environmental conditions of the air conditioner, the most suitable defrosting condition Each is different, the following are examples of several defrosting trigger conditions commonly used in domestic general air conditioners:

The first entry condition: 1. After entering the heating mode or defrosting mode for about 5 minutes, judge according to the maximum difference between the outdoor unit coil temperature and the indoor temperature, and the judgment time is 3 minutes. 2. When the difference between the indoor unit coil temperature and the indoor temperature decreases by more than 5 degrees and lasts for more than 3 minutes. 3. Ensure that the accumulative working time of compressor 1 exceeds 45 minutes. 4. The temperature of the indoor unit coil is less than 48 degrees. If these four conditions are met at the same time, it will start to defrost.

The second condition: the accumulative running time of compressor 1 exceeds 45 minutes, and it runs continuously for more than 20 minutes, and the coil temperature of the indoor unit is lower than the indoor temperature of 16 degrees for 5 minutes, then enters the defrosting state.

The third condition: Compressor 1 has been running for more than 3 hours and continuously running for more than 20 minutes, and the coil temperature of the indoor unit is lower than the indoor temperature of 16 degrees for 5 minutes, then it will enter the defrosting state.

The fourth condition: the outdoor fan 5 enters the overload protection and the outdoor fan 5 stops, and the continuous running time of the outdoor fan 5 is longer than 10 minutes when the outdoor fan 5 is started next time. When the temperature of the machine coil is less than 48 degrees, it will enter the defrosting state.

The fifth condition: if the outdoor fan 5 stops running for two hours and has not entered the defrosting, it will forcefully enter the defrosting.

The heating mode of the air conditioner of the present utility model is: after the refrigerant is discharged from the outlet of the compressor 1, the refrigerant flows to the indoor heat exchanger 8 through the a1 port and the b1 port of the first four-way valve 2, and then passes through the throttling part 6 and the second The c2 port and d2 port of the four-way valve 3 flow to the outdoor heat exchanger 4 for evaporation, flow out through the b2 port and a2 port of the second four-way valve 3, and flow out through the d1 port and c1 port of the first four-way valve 2. The inlet of compressor 1 flows back to compressor 1.

The defrosting mode of the air conditioner of the utility model is as follows: the high-temperature and high-pressure gaseous refrigerant is discharged from the outlet of the compressor 1, flows out through the a1 port and the d1 port of the first four-way valve 2, and flows through the a2 port and the d1 port of the second four-way valve 3 Port d2 enters the defrost from the lower part of the outdoor heat exchanger 4, then flows out from the upper part of the outdoor heat exchanger 4, passes through the b2 port and c2 port of the second four-way valve 3, flows through the throttling component 6 to the indoor heat exchanger 8, and After the low-temperature refrigerant in the indoor heat exchanger 8 is heated by the indoor electric heater 9 , it flows back to the compressor 1 from the inlet of the compressor 1 through the b1 port and the c1 port of the first four-way valve 2 .

The utility model realizes the switching between the heating mode and the defrosting mode by controlling the power-on and power-off of two four-way valves (the first four-way valve 2 and the second four-way valve 3). The pipeline is reversed, and the air conditioner is realized through the cooperation of the compressor 1, the outdoor fan 5, the indoor fan 7 and the indoor electric heater 9 and two four-way valves (the first four-way valve 2 and the second four-way valve 3). The switching of modes can be controlled automatically through the setting of the system, which is convenient to control and quick to adjust.

The defrosting condition of the utility model is that the accumulative defrosting time reaches the set time tx or the coil temperature of the outdoor unit ≥ the set temperature Ts or the current of the compressor 1 reaches or exceeds I _DEFROST for n seconds continuously. Preferably, the conditions for exiting defrosting are that the accumulated defrosting time reaches the set time of 10 minutes or the outdoor unit coil temperature is greater than or equal to the set temperature of 15°C or the current of the compressor 1 reaches or exceeds I _DEFROST for 10 consecutive seconds, wherein the current value I _DEFROST Depends on the air conditioner model.

In the defrosting method of the air conditioner of the present utility model, each specific preferred numerical range is: t1 is 3-8 seconds, t2 is 10-40 seconds, t3 is 10-40 seconds, Tx is 30-35 ° C, Ty is 52-56°C; the optimal value of the above values is: t1 is 5 seconds, t2 is 15 seconds, t3 is 15 seconds, Tx is 32°C, and Ty is 54°C.

Compared with the prior art, the utility model adds the second four-way valve 3, which is opened during defrosting, and the high-temperature refrigerant flows in from the lower part of the outdoor heat exchanger 4 with severe frosting, and flows out from the upper part, which is beneficial to defrosting. At the same time, when defrosting, the indoor fan 7 is reversed, and the indoor electric heater 9 is turned on. The low-temperature refrigerant in the defrosting process is heated by the indoor electric heater 9 and then flows back to the compressor 1. The exhaust temperature of the compressor 1 rises, thereby accelerating the cooling process. The defrosting speed improves the defrosting effect and avoids large fluctuations in room temperature

In the description of the present utility model, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the a1, b1, c1, d1, a2, b2, c2, and d2 ports involved in the present invention are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features quantity.

In this utility model, unless otherwise clearly specified and limited, terms such as "communication" and "conduction" should be understood in a broad sense, for example, it can be through, it can also be connected through a pipeline, or integrated; it can be A fixed connection can also be a detachable connection; it can be a direct connection or an indirect connection through an intermediary, and it can be an internal communication between two elements or an interaction relationship between two elements, unless otherwise clearly defined. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary, and should not be construed as limitations of the present invention, and those of ordinary skill in the art are within the scope of the present invention. Variations, modifications, substitutions and variations can be made to the above-described embodiments.

Claims (3)

1. an air-conditioner, comprise the compressor (1) by pipeline communication, outdoor heat exchanger (4) and indoor heat exchanger (8), it is characterized in that, also comprise the first cross valve (2) and the second cross valve (3), described first cross valve (2) comprises a1 port, b1 port, c1 port and d1 port, described second cross valve (3) comprises a2 port, b2 port, c2 port and d2 port, outlet and the a1 port of described compressor (1) pass through pipeline communication, entrance and the c1 port of described compressor (1) pass through pipeline communication, the two ends of described outdoor heat exchanger (4) are respectively by pipeline communication b2 port and d2 port, the two ends of described indoor heat exchanger (8) are respectively by pipeline communication b1 port and c2 port, d1 port and a2 port pass through pipeline communication,

During described first cross valve (2) energising, a1 port and the conducting of b1 port, c1 port and the conducting of d1 port; During described first cross valve (2) power-off, a1 port and the conducting of d1 port, b1 port and the conducting of c1 port; During described second cross valve (3) energising, a2 port and the conducting of d2 port, b2 port and the conducting of c2 port; During described second cross valve (3) power-off, a2 port and the conducting of b2 port, c2 port and the conducting of d2 port.

2. a kind of air-conditioner according to claim 1, it is characterized in that, the pipeline between c2 port and indoor heat exchanger (8) is provided with throttle part (6), described throttle part (6) is capillary or electric expansion valve.

3. a kind of air-conditioner according to claim 2, it is characterized in that, be provided with outdoor fan (5) at described outdoor heat exchanger (4) place, wind is introduced outdoor heat exchanger (4) by described outdoor fan (5); Indoor fan (7) is provided with at described indoor heat exchanger (8) place, the leeward side of described indoor heat exchanger (8) is provided with the indoor electric heater (9) at least opening operation in described air-conditioner defrost process, when described indoor fan (7) rotates forward, wind is first introduced indoor heat exchanger (8) again through indoor electric heater (9), during described indoor fan (7) reversion, wind is first introduced indoor heat exchanger (8) again through indoor electric heater (9).