A sewage source magnetic levitation centrifugal multi-split air conditioning system

Abstract

This invention relates to the field of air conditioning technology and discloses a sewage source magnetic levitation centrifugal multi-split air conditioning system, including a first magnetic levitation centrifugal compressor and a second magnetic levitation centrifugal compressor. A gas-liquid separator is provided on one side of the first magnetic levitation centrifugal compressor, and a shell-and-tube heat exchanger is provided on the other side of the gas-liquid separator. The sewage source magnetic levitation centrifugal multi-split air conditioning system uses two magnetic levitation centrifugal compressors connected in parallel to increase the cooling capacity of the multi-split system. The magnetic levitation multi-split compressor does not require lubricating oil, overcoming the problem of difficult oil return due to long piping in ordinary multi-split air conditioner compressors. Based on the refrigeration principle and refrigerant characteristics, it overcomes the shortcomings of insufficient cooling capacity in existing multi-split air conditioning systems with the same configuration, improves the refrigeration cycle economy, and the heat exchanger of the indoor unit is a direct expansion type, that is, the refrigerant directly evaporates and exchanges heat with the air, which is more energy-efficient and makes the sewage source magnetic levitation centrifugal multi-split air conditioning system operate stably and reliably.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, specifically to a sewage source magnetic levitation centrifugal multi-split air conditioning system. Background Technology

[0002] Multi-split central air conditioning is a type of user-owned central air conditioning system, commonly known as "one-to-many." It refers to a system where one outdoor unit is connected to two or more indoor units via piping. The outdoor unit uses air-cooled heat exchange, while the indoor units use direct evaporation heat exchange. Multi-split systems are increasingly widely used in small and medium-sized buildings and some public buildings.

[0003] Existing multi-split air conditioning systems are relatively simple. Traditional systems rely solely on the flow of refrigerant between the indoor and outdoor units to complete the cooling or heating cycle. This reliance on refrigerant results in generally poor stability during operation. To address this, a sewage-source magnetic levitation centrifugal multi-split air conditioning system is proposed, with water-cooled heat exchange on the outdoor side. Summary of the Invention

[0004] The purpose of this invention is to provide a sewage source magnetic levitation centrifugal multi-split air conditioning system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a sewage source magnetic levitation centrifugal multi-split air conditioning system, comprising a first magnetic levitation centrifugal compressor and a second magnetic levitation centrifugal compressor, wherein a gas-liquid separator is provided on one side of the first magnetic levitation centrifugal compressor, a shell-and-tube heat exchanger is provided on one side of the gas-liquid separator, a second water pipe is provided on one side of the shell-and-tube heat exchanger, and a plate heat exchanger is provided on the other side of the shell-and-tube heat exchanger;

[0006] The first magnetic levitation centrifugal compressor has a first three-way valve connected to its outlet end via a copper pipe. A first one-way valve is connected between the first magnetic levitation centrifugal compressor and the first three-way valve via a copper pipe. The first magnetic levitation centrifugal compressor has a fifth three-way valve connected to its inlet end via a copper pipe. The second magnetic levitation centrifugal compressor has a fourth one-way valve connected to its outlet end via a copper pipe. The second magnetic levitation centrifugal compressor has a fifth three-way valve connected to its outlet end via a copper pipe. A first balancing solenoid valve is connected between the outlet end and the inlet end of the first magnetic levitation centrifugal compressor via a copper pipe. A second balancing solenoid valve is connected between the outlet end and the inlet end of the second magnetic levitation centrifugal compressor via a copper pipe.

[0007] Preferably, the first three-way outlet is connected to a four-way reversing valve via a copper pipe. A high-pressure switch, a second check valve, and a first pressure sensor are connected between the first three-way outlet and the four-way reversing valve via a copper pipe. The four-way reversing valve is provided with ports C, D, E, and S on its outer side.

[0008] Preferably, the outlet of the four-way reversing valve is connected to the inlet of the gas-liquid separator via a copper pipe, the outlet of the gas-liquid separator is connected to the inlet of the fifth three-way valve via a copper pipe, and a temperature sensor, a second pressure sensor, and a fifth filter are connected between the gas-liquid separator and the fifth three-way valve via a copper pipe.

[0009] Preferably, a bypass solenoid valve is connected between the air inlet end of the second one-way valve and the air inlet end of the gas-liquid separator via a copper pipe, and a second ball valve is connected to one end of the four-way reversing valve via a copper pipe.

[0010] Preferably, the inlet of the shell-and-tube heat exchanger is connected to a first water pipe via a water pipe, the outer side of the first water pipe is inserted into the inner side of a second water pipe, a water supply valve is connected between the inlet of the shell-and-tube heat exchanger and the first water pipe via a water pipe, and a water pump is connected between the outlet of the shell-and-tube heat exchanger and the first water pipe via a water pipe.

[0011] Preferably, the inlet end of the second water pipe is connected to a sewage treatment unit via a water pipe, the inlet end of the sewage treatment unit is connected to the inlet of the urban sewage network via a water pipe, and the outlet end of the second water pipe is connected to the outlet of the urban sewage network via a water pipe.

[0012] Preferably, the liquid outlet of the shell-and-tube heat exchanger is connected to a cooler via a copper tube, the liquid outlet of the cooler is connected to a liquid reservoir via a copper tube, and one end of the four-way reversing valve is connected to the liquid inlet of the shell-and-tube heat exchanger via a copper tube.

[0013] Preferably, the shell-and-tube heat exchanger is provided with a second tee and a third tee on one side. The liquid outlet end of the third tee is connected to a second electronic expansion valve, a third filter, a first electronic expansion valve, and a second filter via copper pipes. One end of the second filter and the third filter is connected to the third tee via copper pipes. A third check valve is provided between the second tee and the third tee. A first filter is provided between the second tee and the shell-and-tube heat exchanger.

[0014] Preferably, the inlet end of the plate heat exchanger is connected to a fourth three-way valve and a third electronic expansion valve via copper pipes. The two inlet ends of the fourth three-way valve are respectively connected to the outlet end of the liquid reservoir and one end of the third electronic expansion valve. The outlet end of one of the plate heat exchangers is connected to a four-way reversing valve. The other plate heat exchanger is connected to several heat exchangers.

[0015] Preferably, a fourth filter, a first ball valve, and a fourth electronic expansion valve are provided between the aforementioned heat exchangers and the plate heat exchanger, and the aforementioned heat exchangers are connected to the second ball valve through copper pipes.

[0016] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0017] I. The wastewater source magnetic levitation centrifugal multi-split air conditioning system of this invention uses two magnetic levitation centrifugal compressors connected in parallel to increase the cooling capacity of the multi-split system. The magnetic levitation multi-split compressor does not require lubricating oil, overcoming the problem of difficult oil return due to long piping in ordinary multi-split air conditioner compressors. Based on the refrigeration principle and refrigerant characteristics, it overcomes the shortcomings of insufficient cooling capacity in existing multi-split air conditioning systems with the same configuration, improving the refrigeration cycle economy. The shell and tube heat exchanger located on one side of the first water pipe does not require a cooling tower. The heat exchanger of the indoor unit is a direct expansion type, that is, the refrigerant directly evaporates and exchanges heat with the air, which is more energy-efficient and makes the wastewater source magnetic levitation centrifugal multi-split air conditioning system operate stably and reliably.

[0018] II. This sewage-source magnetic levitation centrifugal multi-split air conditioning system uses urban sewage as the heat source for the shell-and-tube heat exchanger. The temperature of urban sewage is generally greater than 10℃ and less than 40℃. In summer, when the multi-split air conditioner is cooling, the shell-and-tube heat exchanger acts as a heat-releasing condenser, exchanging heat with the urban sewage. In winter, when the multi-split air conditioner is heating, the shell-and-tube heat exchanger acts as a heat-absorbing evaporator, absorbing heat from the hot water within the shell-and-tube heat exchanger. Only a water pump is needed for power, eliminating the need for a cooling tower. By utilizing the heat from the urban sewage source to exchange heat with the shell-and-tube heat exchanger, the system achieves low carbon emissions, energy savings, and environmental friendliness.

[0019] Third, the high-pressure liquid refrigerant is throttled and depressurized into a low-temperature, low-pressure liquid refrigerant by the action of the third electronic expansion valve. The low-temperature, low-pressure liquid refrigerant enters the plate heat exchanger and evaporates into a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant enters the gas-liquid separator for gas-liquid separation and is finally drawn into the compressor. This cycle increases the refrigerant mass flow rate and refrigerant enthalpy difference, i.e., the "heat recovery cycle," which improves the cooling capacity of the multi-split unit. The purpose of this heating cycle is to increase the heating capacity of the magnetic levitation centrifugal multi-split unit. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram illustrating the principle of the present invention;

[0022] Figure 2 This is a schematic diagram of the compressor part of the present invention;

[0023] Figure 3 This is a schematic diagram of the cooler part of the present invention.

[0024] Explanation of reference numerals in the attached drawings: 1. First magnetic levitation centrifugal compressor; 2. Second magnetic levitation centrifugal compressor; 3. Heat exchanger; 4. First balancing solenoid valve; 5. Second balancing solenoid valve; 6. First check valve; 7. First three-way valve; 8. High-pressure switch; 9. Gas bypass solenoid valve; 10. Second check valve; 11. First pressure sensor; 12. Four-way reversing valve; 13. Shell and tube heat exchanger; 14. Water pump; 15. Wastewater treatment unit; 16. First water pipe; 17. Second water pipe; 18. Water supply valve; 19. First filter; 20. Second three-way valve; 2 1. First electronic expansion valve; 22. Second filter; 23. Second electronic expansion valve; 24. Third filter; 25. Third check valve; 26. Third three-way valve; 27. Cooler; 28. Liquid receiver; 29. ​​Fourth three-way valve; 30. Third electronic expansion valve; 31. Plate heat exchanger; 32. Fourth filter; 33. First ball valve; 34. Fourth electronic expansion valve; 35. Second ball valve; 36. Gas-liquid separator; 37. Temperature sensor; 38. Second pressure sensor; 39. Fifth filter; 40. Fifth three-way valve; 41. Fourth check valve. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0027] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "first", "second", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0029] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0030] Example 1

[0031] Please see Figure 1-3 The present invention provides a technical solution: a sewage source magnetic levitation centrifugal multi-split air conditioning system, including a first magnetic levitation centrifugal compressor 1 and a second magnetic levitation centrifugal compressor 2. A gas-liquid separator 36 is provided on one side of the first magnetic levitation centrifugal compressor 1, a shell-and-tube heat exchanger 13 is provided on one side of the gas-liquid separator 36, a second water pipe 17 is provided on one side of the shell-and-tube heat exchanger 13, and a plate heat exchanger 31 is provided on the other side of the shell-and-tube heat exchanger 13.

[0032] The first magnetic levitation centrifugal compressor 1 has its outlet end connected to a first three-way valve 7 via a copper pipe. A first one-way valve 6 is connected between the first magnetic levitation centrifugal compressor 1 and the first three-way valve 7 via a copper pipe. The first magnetic levitation centrifugal compressor 1 has its inlet end connected to a fifth three-way valve 40 via a copper pipe. The second magnetic levitation centrifugal compressor 2 has its outlet end connected to the inlet end of the first three-way valve 7 via a copper pipe. A fourth one-way valve 41 is connected between the second magnetic levitation centrifugal compressor 2 and the first three-way valve 7 via a copper pipe. The second magnetic levitation centrifugal compressor 2 has its inlet end connected to the outlet end of the fifth three-way valve 40 via a copper pipe. A first balancing solenoid valve 4 is connected between the outlet end and the inlet end of the first magnetic levitation centrifugal compressor 1 via a copper pipe. All connecting copper pipes and refrigeration components are brazed together. A second balancing solenoid valve 5 is connected between the outlet end and the inlet end of the second magnetic levitation centrifugal compressor 2 via a copper pipe. The first one-way valve 6, the second one-way valve 10, the third one-way valve 25, and the fourth one-way valve 41 are all unidirectional flow valves, and cannot flow in the reverse direction.

[0033] The outlet of the first three-way valve 7 is connected to a four-way reversing valve 12 via a copper pipe. A high-pressure switch 8, a second check valve 10, and a first pressure sensor 11 are connected between the first three-way valve 7 and the four-way reversing valve 12 via a copper pipe. Ports C, D, E, and S are respectively located on the outside of the four-way reversing valve 12. The first three-way valve 7 is the exhaust three-way valve, and the fifth three-way valve 40 is the intake three-way valve. The first pressure sensor 11 is a high-pressure sensor. During refrigeration, ports D and C are interconnected, and ports E and S are interconnected. The outlet of the four-way reversing valve 12 is connected to the inlet of the gas-liquid separator 36 via a copper pipe. The outlet of the gas-liquid separator 36 is connected to the inlet of the fifth three-way valve 40 via a copper pipe. A temperature sensor 37, a second pressure sensor 38, and a fifth filter 39 are connected between the liquid separator 36 and the fifth three-way valve 40 via a copper pipe. The second pressure sensor 38 is a low-pressure sensor. The first pressure sensor 11, the second pressure sensor 38, and the temperature sensor 37 work together to control the opening of multiple electronic expansion valves, thereby controlling the refrigerant flow and the operating pressure of the refrigeration system, and protecting the stable and reliable operation of the refrigeration compressor. A fourth filter 32, a first ball valve 33, and a fourth electronic expansion valve 34 are installed between several heat exchangers 3 and the plate heat exchanger 31. Several heat exchangers 3 are connected to the second ball valve 35 via a copper pipe. The first ball valve 33 is used to shut off the liquid.

[0034] A gas bypass solenoid valve 9 is connected to the inlet of the second one-way valve 10 and the inlet of the gas-liquid separator 36 via a copper pipe. One end of the four-way reversing valve 12 is connected to a second ball valve 35 via a copper pipe. The second ball valve 35 is used to open and close the gas. The water inlet of the shell-and-tube heat exchanger 13 is connected to a first water pipe 16 via a water pipe. The outer side of the first water pipe 16 is inserted into the inner side of the second water pipe 17. A water supply valve 18 is connected between the water inlet of the shell-and-tube heat exchanger 13 and the first water pipe 16 via a water pipe. A water pump 14 is connected between the water outlet of the shell-and-tube heat exchanger 13 and the first water pipe 16 via a water pipe. The first water pipe 16 is the heat source clean water pipe, and the second water pipe 17 is the heat source wastewater pipe. The water supply valve 18 can be used to replenish water to the shell-and-tube heat exchanger 13 to prevent water shortage inside the shell-and-tube heat exchanger 13. Figure 1 , Figure 2 and Figure 3 The dashed arrow indicates the direction of refrigerant flow during heating, while the solid arrow indicates the direction of refrigerant flow during cooling.

[0035] The inlet of the second water pipe 17 is connected to the sewage processor 15 via a water pipe. The inlet of the sewage processor 15 is connected to the inlet of the urban sewage network via a water pipe. The outlet of the second water pipe 17 is connected to the outlet of the urban sewage network via a water pipe. The sewage processor 15 treats the sewage in the urban sewage network. The outlet of the shell-and-tube heat exchanger 13 is connected to the cooler 27 via a copper pipe. The outlet of the cooler 27 is connected to the reservoir 28 via a copper pipe. One end of the four-way reversing valve 12 is connected to the inlet of the shell-and-tube heat exchanger 13 via a copper pipe.

[0036] A second three-way valve 20 and a third three-way valve 26 are respectively installed on one side of the shell-and-tube heat exchanger 13. The liquid outlet end of the third three-way valve 26 is connected to a second electronic expansion valve 23, a third filter 24, a first electronic expansion valve 21, and a second filter 22 via copper pipes. One end of the second filter 22 and the third filter 24 is connected to the third three-way valve 26 via copper pipes. A third check valve 25 is installed between the second three-way valve 20 and the third three-way valve 26. A first filter 19 is installed between the second three-way valve 20 and the shell-and-tube heat exchanger 13. The first filter 19 and the second filter 26 are connected to each other. 2. The function of the third filter 24, the fourth filter 32, and the fifth filter 39 is to filter impurities inside the refrigerant. The liquid inlet of the plate heat exchanger 31 is connected to the fourth three-way valve 29 and the third electronic expansion valve 30 through copper pipes. The liquid inlet of the two fourth three-way valves 29 is connected to the liquid outlet of the liquid receiver 28 and one end of the third electronic expansion valve 30, respectively. The liquid outlet of one of the plate heat exchangers 31 is connected to the four-way reversing valve 12. The other plate heat exchanger 31 is connected to several heat exchangers 3. The heat exchangers 3 are located indoors and are used to provide indoor heating and cooling air.

[0037] Working principle: Multiple heat exchangers 3 are located inside the indoor unit, while the first magnetic levitation centrifugal compressor 1, the second magnetic levitation centrifugal compressor 2, and the shell and tube heat exchanger 13 are all installed inside the outdoor unit. When the outdoor unit starts cooling, the refrigerant circulates in multiple sets of copper pipes. The first balancing solenoid valve 4 and the second balancing solenoid valve 5 open when the pressure of the multi-split air conditioning system is too high, protecting the refrigeration compressor to operate stably and reliably.

[0038] During the refrigeration cycle, the refrigerant is discharged as high-temperature and high-pressure refrigerant gas through the outlet of the first magnetic levitation centrifugal compressor 1. The high-temperature and high-pressure refrigerant gas is transported through the first one-way valve 6. At the same time, the refrigerant is discharged as high-temperature and high-pressure refrigerant gas through the outlet of the second magnetic levitation centrifugal compressor 2. The high-temperature and high-pressure refrigerant gas is transported through the fourth one-way valve 41. The high-temperature and high-pressure refrigerant gas that has passed through the first one-way valve 6 and the fourth one-way valve 41 is transported to the inside of the first three-way valve 7 for mixing. When the mixed high-temperature and high-pressure refrigerant gas is transported through the outlet pipe of the first three-way valve 7, when the refrigeration exhaust pressure exceeds the set value, the high-pressure switch 8 is disconnected, causing the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2 to stop, thus protecting the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2.

[0039] The high-temperature and high-pressure refrigerant gas from the first three-way valve 7, after passing through the second one-way valve 10, enters through port D of the four-way reversing valve 12 and flows out from port C. At this time, the first pressure sensor 11 monitors the exhaust pressure of the refrigeration system, which facilitates the control of the loading and unloading of the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2, ensuring stable operation of the system. The gas bypass solenoid valve 9 opens when the pressure of the multi-split air conditioning system is too high, protecting the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2 to operate stably and reliably during refrigeration.

[0040] The high-temperature and high-pressure refrigerant gas at port C of the four-way reversing valve 12 enters the inside of the shell-and-tube heat exchanger 13 for condensation and heat release. The high-temperature and high-pressure liquid after condensation flows out at the liquid outlet of the shell-and-tube heat exchanger 13. The high-temperature and high-pressure refrigerant liquid flows through the first filter 19 and then enters the inside of the second three-way valve 20. At the same time, a portion of the refrigerant flows through the third check valve 25. The high-temperature and high-pressure liquid refrigerant inside the second three-way valve 20 is divided into two paths. One path passes through the first electronic expansion valve 21 and the second filter 22, and the other path passes through the second electronic expansion valve 23 and the third filter 24. Then, they all enter the inside of the third three-way valve 26. The high-temperature and high-pressure liquid refrigerant at the liquid outlet of the third three-way valve 26 mixes with the high-temperature and high-pressure liquid refrigerant at the third check valve 25 and then enters the inside of the cooler 27. The cooled high-temperature and high-pressure liquid refrigerant enters the inside of the receiver 28.

[0041] The high-temperature, high-pressure liquid refrigerant flowing out of the liquid outlet of the receiver 28 enters the inside of the fourth three-way valve 29. The fourth three-way valve 29 divides the high-temperature, high-pressure liquid refrigerant into two paths. One path of the high-temperature, high-pressure liquid refrigerant enters the inside of the plate heat exchanger 31 through the third electronic expansion valve 30, and the other path directly enters the inside of the plate heat exchanger 31 after passing through the fourth three-way valve 29. The high-temperature, high-pressure liquid refrigerant enters the plate heat exchanger 31 for further cooling. After cooling, the low-temperature, high-pressure liquid refrigerant flows out of the plate heat exchanger 31 and is filtered by the fourth filter 32. Then, the low-temperature, high-pressure liquid refrigerant flows through the first ball valve 33 and enters the inside of the heat exchanger 3 of multiple indoor units through the main inlet B. Under the action of the fourth electronic expansion valve 34, the low-temperature, high-pressure liquid refrigerant is converted into a low-temperature, low-pressure liquid refrigerant and enters the heat exchanger 3 of the indoor unit to absorb heat and evaporate into a low-temperature, low-pressure gaseous refrigerant. This process realizes the refrigeration cycle of the heat exchanger 3 of multiple indoor units.

[0042] Low-temperature, low-pressure gaseous refrigerant flowing from multiple heat exchangers 3 gathers together and passes through the main outlet C and then through the second ball valve 35. At this point, the low-temperature, low-pressure gaseous refrigerant flows out through the four-way reversing valve 12E port and then out through the S port. The low-temperature, low-pressure gaseous refrigerant from the S port enters the gas-liquid separator 36 for gas-liquid separation. The low-temperature, low-pressure gaseous refrigerant after gas-liquid separation flows out from the gas outlet of the gas-liquid separator 36. The low-temperature, low-pressure gaseous refrigerant then enters the fifth filter 39 and flows out. The low-temperature, low-pressure gaseous refrigerant then enters the fifth three-way valve 40, which divides the low-temperature, low-pressure gaseous refrigerant into two paths. One path enters the first magnetic levitation centrifugal compressor 1 and is compressed, while the other path enters the second magnetic levitation centrifugal compressor 2 and is drawn in and compressed. A multi-split air conditioning refrigeration cycle is realized by connecting two magnetic levitation centrifugal compressors in parallel. In this process, the low-temperature and low-pressure refrigerant liquid evaporates into low-temperature and low-pressure gaseous refrigerant through the plate heat exchanger 31 and enters the gas-liquid separator 36 for gas-liquid separation. This cycle increases the refrigerant mass flow rate and refrigerant enthalpy difference, i.e., the "heat recovery cycle" to improve the refrigeration capacity of the multi-split air conditioning system. The purpose of this refrigeration cycle is to increase the refrigeration capacity of the magnetic levitation centrifugal multi-split air conditioning system.

[0043] This sewage source magnetic levitation centrifugal multi-split air conditioning system uses urban sewage as the heat source for shell-and-tube heat exchanger 13. The temperature of urban sewage is generally greater than 10℃ and less than 40℃. During the summer cooling period, the shell-and-tube heat exchanger 13 acts as a heat-releasing condenser. The heat released by the shell-and-tube heat exchanger 13 exchanges heat with the urban sewage. Only the water pump 14 is needed to provide power, and there is no need for cooling towers, etc. After the urban sewage has passed through the sewage treatment system, including filtration, water treatment, and water temperature regulation, it exchanges heat with the first water pipe 16 in the second water pipe 17. The water temperature in the first water pipe 16 decreases while the sewage temperature increases. The water pump 14 provides the power for water circulation.

[0044] Low-temperature water in the first water pipe 16 flows into the shell-and-tube heat exchanger 13 through the water inlet and exchanges heat with the high-temperature, high-pressure refrigerant gas flowing into the liquid inlet of the shell-and-tube heat exchanger 13. This causes the refrigerant in the shell-and-tube heat exchanger 13 to condense and release heat into a high-temperature, high-pressure liquid refrigerant. In this invention, the sewage source magnetic levitation centrifugal multi-split air conditioning system uses two magnetic levitation centrifugal compressors connected in parallel to increase the cooling capacity of the multi-split system. The magnetic levitation multi-split unit does not require lubricating oil, overcoming the problem that ordinary compressors in multi-split air conditioners have difficulty returning oil due to long piping. Based on the refrigeration principle and refrigerant characteristics, it overcomes the shortcomings of insufficient cooling capacity in existing multi-split air conditioning systems with the same configuration, and improves the refrigeration cycle economy. The shell-and-tube heat exchanger 13 located on one side of the first water pipe 16 does not require a cooling tower. The heat exchanger 3 of the indoor unit is a direct expansion type, that is, the refrigerant directly evaporates and exchanges heat with the air, which is more energy-efficient and makes the sewage source magnetic levitation centrifugal multi-split air conditioning system operate stably and reliably.

[0045] Example 2

[0046] The difference between this embodiment and Embodiment 1 is that:

[0047] During the heating cycle, in the sewage source magnetic levitation centrifugal multi-split air conditioning system, the outdoor heating is carried out at the ambient temperature, and the refrigerant in the outdoor unit circulates in the copper pipes. The first balancing solenoid valve 4 and the second balancing solenoid valve 5 open when the pressure of the multi-split air conditioning system is too high, protecting the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2 to ensure stable and reliable operation.

[0048] The refrigerant is discharged as high-temperature, high-pressure refrigerant gas from the outlet of the first magnetic levitation centrifugal compressor 1 and transported through the first one-way valve 6. At the same time, the refrigerant is discharged as high-temperature, high-pressure refrigerant gas from the outlet of the second magnetic levitation centrifugal compressor 2. The high-temperature, high-pressure refrigerant gas is transported through the fourth one-way valve 41. The high-temperature, high-pressure refrigerant gas that has passed through the first one-way valve 6 and the fourth one-way valve 41 is transported to the inside of the first three-way valve 7 for mixing. When the mixed high-temperature, high-pressure refrigerant gas is transported through the outlet pipe of the first three-way valve 7, the high-pressure switch 8 is disconnected when the refrigeration exhaust pressure exceeds the set value, causing the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2 to stop, thus protecting the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2.

[0049] During heating, the D port and E port of the four-way reversing valve 12 are interconnected, and the C port and S port are interconnected. The first pressure sensor 11 monitors the exhaust pressure of the refrigeration system, which facilitates the control of the loading and unloading of the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2, ensuring stable system operation. The gas bypass solenoid valve 9 opens when the pressure of the multi-split air conditioning system is too high, protecting the first magnetic levitation centrifugal compressor 1 and the second magnetic levitation centrifugal compressor 2 to operate stably and reliably during cooling.

[0050] High-temperature and high-pressure refrigerant gas from port E of the four-way reversing valve 12 passes through the inside of the second ball valve 35 and then enters the heat exchangers 3 of multiple indoor units through the main outlet C for condensation and heat release, thereby enabling the heat exchangers 3 of multiple indoor units to provide heating. After condensation and heat release in the multiple heat exchangers 3, the high-temperature and high-pressure liquid refrigerant is mixed together under the action of multiple fourth electronic expansion valves 34 and flows through the main inlet B and the first ball valve 33. At the same time, the high-temperature and high-pressure liquid refrigerant is filtered by the fourth filter 32. Then, the high-temperature and high-pressure liquid refrigerant is recooled and subcooled from the liquid inlet end of the plate heat exchanger 31. The cooled low-temperature and high-pressure liquid refrigerant flows out from the liquid outlet end of the plate heat exchanger 31.

[0051] Meanwhile, the low-temperature, high-pressure liquid refrigerant is divided into two paths after passing through the fourth three-way valve 29. One path is the high-temperature, high-pressure liquid refrigerant entering the liquid receiver 28. Then, the high-temperature, high-pressure liquid refrigerant inside the liquid receiver 28 flows into the cooler 27. After cooling, the high-temperature, high-pressure liquid refrigerant enters the third three-way valve 26. At this time, the third one-way valve 25 is closed in reverse, and no refrigerant flows. The high-temperature, high-pressure liquid refrigerant passing through the third three-way valve 26 is divided into two paths. One path passes through the second filter 22 and enters the first electronic expansion valve 21, where it is throttled and depressurized into a low-temperature, low-pressure liquid refrigerant. Then, it enters the second three-way valve 20. The other path is the high-temperature, high-pressure liquid refrigerant flowing through the third filter 24 and entering the inner side of the second electronic expansion valve 23, where it is throttled and depressurized into a low-temperature, low-pressure liquid refrigerant. Both paths of low-temperature, low-pressure liquid refrigerant enter the inner side of the second three-way valve 20. Then, the low-temperature, low-pressure liquid refrigerant output from the liquid outlet of the second three-way valve 20 passes through the first filter 19 and enters the shell-and-tube heat exchanger 13 to absorb heat and evaporate into a low-temperature, low-pressure refrigerant gas.

[0052] Low-temperature, low-pressure refrigerant gas enters the four-way reversing valve 12 through port C and flows out from port S. The low-temperature, low-pressure refrigerant gas from port S enters the gas-liquid separator 36 for gas-liquid separation. After gas-liquid separation, the low-temperature, low-pressure refrigerant gas enters the fifth filter 39 and then flows out. The low-temperature, low-pressure refrigerant gas enters the fifth three-way valve 40, which divides the low-temperature, low-pressure refrigerant gas into two streams. One stream enters the first magnetic levitation centrifugal compressor 1 and is drawn in and compressed, while the other stream enters the second magnetic levitation centrifugal compressor 2 and is drawn in and compressed, thus realizing a multi-split air conditioning heating cycle with two magnetic levitation centrifugal compressors in parallel.

[0053] In this process, the high-pressure liquid refrigerant is throttled and depressurized into a low-temperature, low-pressure liquid refrigerant by the action of the third electronic expansion valve 30. The low-temperature, low-pressure liquid refrigerant enters the plate heat exchanger 31 and evaporates into a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant enters the gas-liquid separator 36 for gas-liquid separation and is finally drawn into the compressor. This cycle increases the refrigerant mass flow rate and refrigerant enthalpy difference, i.e., the "heat recovery cycle" to improve the cooling capacity of the multi-split unit. The purpose of this heating cycle is to increase the heating capacity of the magnetic levitation centrifugal multi-split unit.

[0054] This sewage-source magnetic levitation centrifugal multi-split air conditioning system uses urban sewage as the heat source for the shell-and-tube heat exchanger 13. The temperature of the urban sewage is generally greater than 10℃ and less than 40℃. During winter heating, the shell-and-tube heat exchanger 13 acts as a heat-absorbing evaporator. The heat absorbed by the shell-and-tube heat exchanger 13 comes from the heat of the hot water in the shell-and-tube heat exchanger 13. The hot water in the shell-and-tube heat exchanger 13 exchanges heat with the urban sewage, further increasing the water temperature in the shell-and-tube heat exchanger 13. Only the water pump 14 is needed to provide power; no cooling tower is required. After undergoing sewage treatment processes including filtration, water quality treatment, and water temperature regulation, the urban sewage exchanges heat with the first water pipe 16 in the second water pipe 17. The water temperature in the first water pipe 16 increases, while the water temperature in the second water pipe 17 decreases.

[0055] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. It should be noted that implementations not illustrated or described in the drawings or the main text of the specification are forms known to those skilled in the art and are not described in detail. Furthermore, the definitions of the components described above are not limited to the various specific structures, shapes, or methods mentioned in the embodiments, and those skilled in the art can easily modify or substitute them.

[0056] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0057] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sewage source magnetic suspension centrifugal multi-connected air conditioning system, comprising a first magnetic suspension centrifugal compression machine (1) and a second magnetic suspension centrifugal compression machine (2), characterized in that: The first magnetic levitation centrifugal compression molding machine (1) is provided with a gas-liquid separator (36) on one side, a shell-and-tube heat exchanger (13) is provided on one side of the gas-liquid separator (36), a second water pipe (17) is provided on one side of the shell-and-tube heat exchanger (13), and a plate heat exchanger (31) is provided on the other side of the shell-and-tube heat exchanger (13). The first magnetic levitation centrifugal compression molding machine (1) has a first three-way valve (7) connected to its outlet end via a copper pipe. A first one-way valve (6) is connected between the first magnetic levitation centrifugal compression molding machine (1) and the first three-way valve (7) via a copper pipe. A fifth three-way valve (40) is connected to the inlet end of the first magnetic levitation centrifugal compression molding machine (1) via a copper pipe. The second magnetic levitation centrifugal compressor (2) has its outlet end connected to the inlet end of the first three-way valve (7) via a copper pipe. A fourth one-way valve (41) is connected between the second magnetic levitation centrifugal compressor (2) and the first three-way valve (7) via a copper pipe. The inlet end of the second magnetic levitation centrifugal compressor (2) is connected to the outlet end of the fifth three-way valve (40) via a copper pipe. A first balancing solenoid valve (4) is connected between the outlet end and the inlet end of the first magnetic levitation centrifugal compression molding machine (1). A second balancing solenoid valve (5) is connected between the outlet end and the inlet end of the second magnetic levitation centrifugal compressor (2) via a copper pipe. The first three-way valve (7) is connected to a four-way reversing valve (12) through a copper pipe at its outlet end. A high-pressure switch (8), a second check valve (10) and a first pressure sensor (11) are connected between the first three-way valve (7) and the four-way reversing valve (12) through a copper pipe. The four-way reversing valve (12) is provided with C port, D port, E port and S port on its outer side. The outlet of the four-way reversing valve (12) is connected to the inlet of the gas-liquid separator (36) through a copper pipe. The outlet of the gas-liquid separator (36) is connected to the inlet of the fifth three-way valve (40) through a copper pipe. A temperature sensor (37), a second pressure sensor (38), and a fifth filter (39) are connected between the gas-liquid separator (36) and the fifth three-way valve (40) through a copper pipe. The second one-way valve (10) is connected to the gas-liquid separator (36) via a copper pipe, and a gas bypass solenoid valve (9) is connected to one end of the four-way reversing valve (12) via a copper pipe, and a second ball valve (35) is connected to one end of the four-way reversing valve (12). The inlet of the shell-and-tube heat exchanger (13) is connected to a first water pipe (16) via a water pipe. The outer side of the first water pipe (16) is inserted into the inner side of a second water pipe (17). A water supply valve (18) is connected between the inlet of the shell-and-tube heat exchanger (13) and the first water pipe (16) via a water pipe. A water pump (14) is connected between the outlet of the shell-and-tube heat exchanger (13) and the first water pipe (16) via a water pipe. The inlet of the plate heat exchanger (31) is connected to a fourth three-way valve (29) and a third electronic expansion valve (30) via copper pipes. The inlet of the two fourth three-way valves (29) is connected to the outlet of the reservoir (28) and one end of the third electronic expansion valve (30), respectively. The outlet of one of the plate heat exchangers (31) is connected to a four-way reversing valve (12), and the other plate heat exchanger (31) is connected to several heat exchangers (3).

2. The sewage source magnetic levitation centrifugal multi-split air conditioning system according to claim 1, characterized in that: The inlet of the second water pipe (17) is connected to the sewage processor (15) through a water pipe. The inlet of the sewage processor (15) is connected to the inlet of the urban sewage network through a water pipe. The outlet of the second water pipe (17) is connected to the outlet of the urban sewage network through a water pipe.

3. A sewage source magnetic levitation centrifugal multi-split air conditioning system according to claim 2, characterized in that: The outlet end of the shell-and-tube heat exchanger (13) is connected to a cooler (27) via a copper tube, and the outlet end of the cooler (27) is connected to a reservoir (28) via a copper tube. One end of the four-way reversing valve (12) is connected to the inlet end of the shell-and-tube heat exchanger (13) via a copper tube.

4. A sewage source magnetic levitation centrifugal multi-split air conditioning system according to claim 3, characterized in that: The shell-and-tube heat exchanger (13) is provided with a second tee (20) and a third tee (26) on one side. The liquid outlet of the third tee (26) is connected to a second electronic expansion valve (23), a third filter (24), a first electronic expansion valve (21), and a second filter (22) through copper pipes. One end of the second filter (22) and the third filter (24) is connected to the third tee (26) through copper pipes. A third check valve (25) is provided between the second tee (20) and the third tee (26). A first filter (19) is provided between the second tee (20) and the shell-and-tube heat exchanger (13).

5. A sewage source magnetic levitation centrifugal multi-split air conditioning system according to claim 4, characterized in that: A fourth filter (32), a first ball valve (33) and a fourth electronic expansion valve (34) are provided between several heat exchangers (3) and plate heat exchangers (31), and several heat exchangers (3) are connected to a second ball valve (35) through copper pipes.

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