CN-122015211-A - Magnetic suspension centrifugal compressor air conditioning system with partition defrosting function and control method

CN122015211ACN 122015211 ACN122015211 ACN 122015211ACN-122015211-A

Abstract

The invention discloses a magnetic suspension centrifugal compressor air conditioning system with partition defrosting and a control method, wherein an outlet of a primary compressor is connected with an inlet of a secondary compressor; the first three-way valve, the second three-way valve and the third three-way valve are all connected with the exhaust end of the secondary compressor, the inlet of the first outdoor heat exchanger is connected with the first three-way valve, the inlet of the second outdoor heat exchanger is connected with the second three-way valve, the inlet of the at least one indoor heat exchanger is connected with the third three-way valve, the heat exchanger is provided with a first heat exchange side and a second heat exchange side, the inner valve is connected with the outlet of the at least one indoor heat exchanger, the other end of the inner valve is connected with the first heat exchange side of the heat exchanger, the second heat exchange side supplements air by the outlet side of the inner valve, and the refrigerant subjected to heat exchange of the heat exchanger is introduced between the primary compressor and the secondary compressor. The invention can effectively improve the running stability and the system reliability of the magnetic suspension centrifugal compressor.

Inventors

LI XIANGDONG
QIU XIAOLIANG
ZHOU HANG
ZHANG WEIJIE
LIU XILI
ZHAO TING

Assignees

天玑动能(北京)磁悬浮技术发展有限公司

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (10)

1. A magnetic levitation centrifugal compressor air conditioning system having zoned defrosting, comprising: The system comprises a first-stage compressor (11) and a second-stage compressor (12), wherein an outlet of the first-stage compressor (11) is connected with an inlet of the second-stage compressor (12) and is used for carrying out two-stage compression on refrigerant; The first three-way valve (21), the second three-way valve (22) and the third three-way valve (23) are connected with the exhaust end of the secondary compressor (12) and are used for selectively distributing the refrigerant discharged by the secondary compressor (12); a first outdoor heat exchanger (31) having an inlet connected to the first three-way valve (21); a second outdoor heat exchanger (32) having an inlet connected to the second three-way valve (22); at least one indoor heat exchanger, the inlet of which is connected with a third three-way valve (23) for exchanging heat with indoor air; the heat exchanger (51) has a first heat exchange side and a second heat exchange side; At least an inner valve, which is correspondingly connected with the outlet of the at least one indoor heat exchanger, and the other end of the inner valve is connected with the first heat exchange side of the heat exchanger (51); the second heat exchange side supplements air by utilizing the outlet side of the inner valve and is connected with the primary compressor (11) and the secondary compressor (12); The refrigerant subjected to heat exchange by the heat exchanger (51) is introduced between the first-stage compressor (11) and the second-stage compressor (12) to form intermediate air supplementing, and the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) can alternately enter a defrosting state under the condition of not performing integral reverse circulation switching of the system by switching control of the first three-way valve (21) and the second three-way valve (22).
2. An air conditioning system according to claim 1, characterized in that the heat exchanger (51) is a plate heat exchanger (51).
3. An air conditioning system according to claim 1, characterized in that the first three-way valve (21), the second three-way valve (22) and the third three-way valve (23) each have a return air connection function for returning the refrigerant evaporated in the corresponding heat exchanger to the inlet of the primary compressor (11).
4. An air conditioning system according to claim 1, characterized in that a gas supplementing valve (52) is connected to the second heat exchanging side of the heat exchanger (51) for controlling a part of the refrigerant to enter the second heat exchanging side of the heat exchanger (51) after being throttled, so that the refrigerant in different pressure states exchanges heat and is led between the primary compressor (11) and the secondary compressor (12).
5. An air conditioning system according to claim 1, characterized in that a first three-way valve (21) is provided between the two-stage compressor (12) and the first outdoor heat exchanger (31) for selectively letting refrigerant from the two-stage compressor (12) into the first outdoor heat exchanger (31), the first outdoor heat exchanger (31) being connected to the inlet of the one-stage compressor (11) through the first three-way valve (21); the second three-way valve (22) is arranged between the secondary compressor (12) and the second outdoor heat exchanger (32) and is used for selectively enabling the refrigerant from the secondary compressor (12) to enter the second outdoor heat exchanger (32), and the second outdoor heat exchanger (32) is connected with the inlet of the primary compressor (11) through the second three-way valve (22); The third three-way valve (23) is arranged between the secondary compressor (12) and the indoor heat exchanger and is used for selectively enabling the refrigerant from the secondary compressor (12) to enter the indoor heat exchanger, and the refrigerant output by the indoor heat exchanger is connected with the inlet of the primary compressor (11).
6. The air conditioning system according to claim 1, wherein in the zone defrosting operation state, one of the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) is connected to the two-stage compressor (12) by controlling valve positions of the first three-way valve (21) and the second three-way valve (22) to receive refrigerant from the two-stage compressor (12) to defrost the outdoor heat exchanger by releasing heat; a third three-way valve (23) is kept connected with the indoor heat exchanger, so that the refrigerant from the secondary compressor (12) enters the indoor heat exchanger and releases heat to the indoor environment, After defrosting of the one outdoor heat exchanger is completed, the other outdoor heat exchanger is enabled to enter a heat release defrosting state by switching valve positions of the first three-way valve (21) and the second three-way valve (22).
7. An air conditioning system according to claim 2, characterized in that in the cooling operation state, by controlling the valve positions of the first three-way valve (21) and the second three-way valve (22), the refrigerant from the two-stage compressor (12) is made to enter the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) at the same time, and the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) are made to release heat to the outdoor environment; The valve position of the third three-way valve (23) is controlled, so that the refrigerant from the secondary compressor (12) enters the indoor heat exchanger after being radiated by the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32), and the indoor heat exchanger absorbs the heat of the indoor environment and realizes refrigeration; The refrigerant evaporated by the indoor heat exchanger enters the plate heat exchanger (51) for heat exchange under the control of the internal valve, and returns to the first-stage compressor (11) after the heat exchange is completed, so that closed circulation in a refrigeration running state is formed.
8. An air conditioning system according to claim 2, characterized in that in the heating operating state, the valve position of the third three-way valve (23) is controlled so that the refrigerant from the two-stage compressor (12) enters the indoor heat exchanger and the indoor heat exchanger releases heat to the indoor environment; controlling valve positions of a first three-way valve (21) and a second three-way valve (22) to enable a first outdoor heat exchanger (31) and a second outdoor heat exchanger (32) to be connected with a first-stage compressor (11) so as to absorb heat from an outdoor environment; The refrigerant evaporated by the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) returns to the first-stage compressor (11) under the control of the three-way valve, and enters the indoor heat exchanger again after being compressed by the first-stage compressor (11) and the second-stage compressor (12), so that a closed cycle in a heating running state is formed; The plate heat exchanger (51) is used for enabling part of refrigerant to participate in heat exchange before entering the secondary compressor (12) so as to improve the operation stability of the system under heating working conditions.
9. The air conditioning system of claim 1, further comprising a first valve (41) coupled to an outlet of the first outdoor heat exchanger (31) and a second valve (42) coupled to an outlet of the second outdoor heat exchanger (32).
10. A control method using the air conditioning system according to any one of claims 1 to 9, comprising: Selectively distributing the refrigerant discharged by the secondary compressor (12) by controlling valve positions of the first three-way valve (21), the second three-way valve (22) and the third three-way valve (23), so that the system is switched among a refrigeration running state, a heating running state and a partition defrosting running state; In a refrigeration running state, the first three-way valve (21) and the second three-way valve (22) are controlled to enable the refrigerant to enter the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) and release heat to the outdoor environment, and the third three-way valve (23) is controlled to enable the refrigerant to enter the indoor heat exchanger and absorb heat of the indoor environment, so that refrigeration running is realized; in a heating operation state, the third three-way valve (23) is controlled to enable the refrigerant to enter the indoor heat exchanger and release heat to the indoor environment, the first three-way valve (21) and the second three-way valve (22) are controlled to enable the refrigerant to enter the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) and absorb heat from the outdoor environment, and therefore the heating operation is achieved; under the state of partition defrosting operation, the valve positions of the first three-way valve (21) and the second three-way valve (22) are switched, so that the first outdoor heat exchanger (31) and the second outdoor heat exchanger (32) alternately receive the refrigerant from the secondary compressor (12) to perform heat release defrosting, and the third three-way valve (23) is kept connected with the indoor heat exchanger to continuously supply heat to the indoor environment in the defrosting process; and in the refrigerating operation state, the heating operation state and the partition defrosting operation state, the heat exchanger (51) is utilized to exchange heat of the refrigerants in different pressure states, and the refrigerants after heat exchange are introduced between the primary compressor (11) and the secondary compressor (12) to form intermediate air supplementing, so that the stability of the system operation is improved.

Description

Magnetic suspension centrifugal compressor air conditioning system with partition defrosting function and control method Technical Field The invention relates to an air conditioner compressor technology, in particular to a magnetic suspension centrifugal compressor air conditioning system with partition defrosting and a control method. Background During winter heating operation, heat pump air conditioners typically absorb heat from ambient air through an outdoor heat exchanger and release heat to the indoor environment. Because the outdoor environment temperature is lower, the outdoor heat exchanger is in a low-temperature state under the heating working condition, and when the surface temperature is lower than the dew point temperature of the air and lower than zero ℃, the moisture in the air is easy to condense and frost on the surface of the outdoor heat exchanger. Along with the extension of the running time, the frost layer is continuously thickened and gradually covers the surface of the heat exchanger and the air circulation channel, so that the heat exchange efficiency is obviously reduced, and the outdoor heat exchanger can not absorb heat from the air effectively when severe, so that the normal heating running of the air conditioning system is affected. In order to eliminate the frost layer on the surface of the outdoor heat exchanger, the existing heat pump air conditioner usually enters a forced defrosting mode after detecting a frosting working condition. At present, a common defrosting mode is reverse circulation defrosting, namely, the flow direction of the refrigerant is switched through a four-way valve, so that an air conditioning system is switched from a heating mode to a refrigerating mode, and the outdoor heat exchanger is heated and defrosted by using high-temperature refrigerant. In the reverse circulation defrosting process, the indoor heat exchanger is converted from an original heat release state to a heat absorption state, and the outdoor heat exchanger is converted from the heat absorption state to the heat release state, so that the frost layer is removed. However, the reverse circulation defrosting mode has obvious limitations in the magnetic suspension centrifugal compressor air conditioning unit. The magnetic suspension centrifugal compressor is sensitive to system working condition changes, and the stable operation of the magnetic suspension centrifugal compressor depends on the continuity and stability of the flow, the pressure and the flow direction of the refrigerant. When the system is used for reverse circulation defrosting or is switched from a defrosting state to a heating state, the components such as the rotating speed of the compressor, the reversing of the four-way valve, the start and stop of the fan and the like need to frequently act, and severe changes of the flow direction, the pressure and the mass flow of the refrigerant are easily caused. In the process, a certain amount of liquid refrigerant is often entrained in the gaseous refrigerant to return to the compressor, so that the operation risks such as surge, rotor instability and even liquid impact of the magnetic suspension centrifugal compressor are very easy to occur, and the reliability and the service life of the system are seriously affected. Furthermore, reverse cycle defrosting of existing devices often requires interruption of continuous heat supply to the room during defrosting, resulting in fluctuation of indoor temperature, reducing user comfort. For a heat pump air conditioning system adopting a magnetic suspension centrifugal compressor, how to realize defrosting operation without stopping a machine and interrupting heat supply on the premise of ensuring stable operation of the compressor becomes a technical problem to be solved. Disclosure of Invention The invention aims to provide a magnetic suspension centrifugal compressor air conditioning system with partition defrosting and a control method, which are used for solving the problems in the prior art. The invention discloses a magnetic suspension centrifugal compressor air conditioning system with partitioned defrosting, which comprises a first-stage compressor (11) and a second-stage compressor (12), wherein an outlet of the first-stage compressor (11) is connected with an inlet of the second-stage compressor (12) and is used for carrying out two-stage compression on refrigerant, a first three-way valve (21), a second three-way valve (22) and a third three-way valve (23) are respectively connected with an exhaust end of the second-stage compressor (12) and are used for selectively distributing refrigerant discharged by the second-stage compressor (12), a first outdoor heat exchanger (31) is connected with the first three-way valve (21) at an inlet thereof, a second outdoor heat exchanger (32) is connected with the second three-way valve (22) at an inlet thereof and is connected with the third three-way valve (23) for carrying out heat ex