Multi-split parallel system without stopping indoor fan during defrosting

Abstract

The utility model discloses a multi-split air-conditioning parallel system without stopping an indoor fan during defrosting, which relates to the field of air-conditioning systems and comprises a plurality of indoor units arranged in parallel, a defrosting system and a heat supply system, the defrosting system and the heat supply system are respectively connected with the indoor units in parallel, the defrosting system operates at low frequency, and the heat supply system operates at high frequency to ensure sufficient refrigerant. During defrosting, one outdoor unit switches the four-way valve to defrost, and other outdoor units still operate in a normal heating mode; in this way, through effective control, the outdoor units are sequentially defrosted, continuous heat supply can be achieved, it is guaranteed that the indoor unit fan does not stop due to cold air, and the comfort of the indoor environment is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of air conditioning systems, in particular to a multi-connected parallel system for defrosting without stopping indoor fans. Background Art

[0002] Most of the existing defrosting modes of multi-split parallel systems (with at least two or more outdoor units) are to switch the four-way valve to defrost by stopping (or reducing the frequency). This defrosting method has the following two disadvantages:

[0003] 1. During the defrosting process, the indoor unit fan stops running to prevent wind cooling, and the indoor unit coil acts as an evaporator, absorbing heat, causing the indoor temperature to drop, resulting in large temperature fluctuations and poor user experience;

[0004] 2. During the defrosting process, a large amount of liquid refrigerant returns to the suction side of the air-conditioning system, increasing the possibility of liquid return to the compressor. Liquid return to the compressor poses a risk of burning the compressor, and liquid return can easily cause the compressor to lack oil and be damaged. Utility Model Content

[0005] The purpose of the utility model is to overcome the shortcomings of the prior art and to provide a multi-split parallel system that defrosts without stopping the indoor fan. During defrosting, one outdoor unit switches the four-way valve to defrost, and the other outdoor units are still in normal heating operation. In this way, through effective control, the outdoor units enter defrosting in turn, and continuous and uninterrupted heat supply can be achieved to ensure that the indoor fan does not stop due to cold wind, thereby ensuring the comfort of the indoor environment.

[0006] The purpose of the utility model is to achieve the following technical solution: the multi-split parallel system without stopping the indoor fan for defrosting comprises a plurality of indoor units arranged in parallel and a defrosting system and a heating system respectively connected in parallel with each indoor unit.

[0007] The heating system includes an outdoor heat exchanger on the heating side, a heating four-way valve, a gas-liquid separator on the heating side, a heating compressor and an oil separator on the heating side. The low-temperature refrigerant flowing out of the outlet of each indoor unit is connected to the inlet of the outdoor heat exchanger on the heating side through a pipeline. The outlet of the outdoor heat exchanger on the heating side is connected to the C port of the heating four-way valve. The S port of the heating four-way valve is connected to the inlet of the gas-liquid separator on the heating side. The outlet of the gas-liquid separator on the heating side is connected to the air intake port of the heating compressor through a pipeline. The exhaust port of the heating compressor discharges the high-temperature refrigerant and is connected to the oil separator on the heating side. The oil separator on the heating side is connected to the D port of the heating four-way valve through a pipeline. The E port of the heating four-way valve is connected to the inlet of each indoor unit through a pipeline.

[0008] The defrost system includes a defrost four-way valve, a defrost side gas-liquid separator, a defrost compressor, a defrost side oil separator and a defrost side outdoor heat exchanger. The high-temperature refrigerant flowing out of the E port of the heating four-way valve is also connected to the E port of the defrost four-way valve through a pipeline. The S port of the defrost four-way valve is connected to the inlet of the defrost side gas-liquid separator. The outlet of the defrost side gas-liquid separator is connected to the suction port of the defrost compressor through a pipeline. The exhaust port of the defrost compressor is connected to the defrost side oil separator. The defrost side oil separator is connected to the D port of the defrost four-way valve through a pipeline. The C port of the defrost four-way valve is connected to the inlet of the outdoor heat exchanger on the defrost side. After heat exchange, the low-temperature refrigerant discharged from the outlet of the outdoor heat exchanger on the defrost side is connected to the inlet of the outdoor heat exchanger on the heating side through a pipeline, forming a whole refrigerant flow cycle.

[0009] The defrosting system operates at a low frequency and the heating system operates at a high frequency to ensure sufficient refrigerant.

[0010] As a further technical solution, an electronic expansion valve assembly is connected to the outlet pipe of the outdoor heat exchanger on the defrost side and the inlet pipe of the outdoor heat exchanger on the heating side. The electronic expansion valve assembly includes an electronic expansion valve and a one-way valve connected in parallel.

[0011] As a further technical solution, an outlet filter is also arranged on the outlet pipe of the outdoor heat exchanger on the defrost side, and an inlet filter is also arranged on the inlet pipe of the outdoor heat exchanger on the heating side; the E port of the defrost four-way valve is connected to an inlet filter, and the E port of the heating four-way valve is connected to an outlet filter.

[0012] As a further technical solution, a branch bypass is set on the connecting pipeline between the defrost side gas-liquid separator and the defrost compressor to connect to the defrost side oil separator, and a branch bypass is also set on the connecting pipeline between the heating side gas-liquid separator and the heating compressor to connect to the heating side oil separator. Both branches are connected with capillaries and a third filter.

[0013] As a further technical solution, the oil drain ports of both the defrosting compressor and the heating compressor are connected to the corresponding exhaust ports through pipeline bypass.

[0014] As a further technical solution, a one-way valve is arranged on the pipeline between the defrost side oil separator and the D port of the defrost four-way valve, and a one-way valve is also arranged on the pipeline between the heating side oil separator and the D port of the heating four-way valve.

[0015] As a further technical solution, an electronic expansion valve is provided on the outlet pipeline of each indoor unit.

[0016] As a further technical solution, the defrost system and the heating system back up each other, and the circulation flow mode of the refrigerant is adjusted by the different flow directions of the defrost four-way valve and the heating four-way valve.

[0017] The beneficial effects of the utility model are:

[0018] 1. The indoor heating mechanism is uninterrupted, the heating effect is continuous and good, ensuring small indoor temperature fluctuations and good user experience;

[0019] 2. Because other outdoor units in the system are still running in heating mode, the refrigerant system is just the opposite of the defrosting system, so the refrigerant returned to the defrosting compressor is a high-temperature gaseous refrigerant, without the risk of liquid compression; reduce the risk of liquid return during unit defrosting to damage the compressor or liquid return to cause oil shortage and damage the compressor;

[0020] 3. The defrosting outdoor unit has a higher enthalpy value of inhaled refrigerant, the compressor is highly efficient, the defrosting efficiency is faster, and the defrosting time is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the utility model.

[0022] Figure 2 It is a structural schematic diagram of the defrosting system in the utility model.

[0023] Explanation of the reference numerals in the accompanying drawings: defrost system 100, heating system 200, indoor unit 1, electronic expansion valve 2, inlet filter 31, outlet filter 32, third filter 33, defrost four-way valve 41, heating four-way valve 42, defrost side outdoor heat exchanger 51, heating side outdoor heat exchanger 52, defrost compressor 61, heating compressor 62, defrost side gas-liquid separator 71, heating side gas-liquid separator 72, defrost side oil separator 81, heating side oil separator 82, one-way valve 9, capillary tube 10. DETAILED DESCRIPTION

[0024] The utility model will be described in detail below with reference to the accompanying drawings:

[0025] Example: As attached Figure 1 , 2 As shown, the multi-split parallel system with defrosting without stopping the indoor fan includes a defrost system 100, a heating system 200, an indoor unit 1, an electronic expansion valve 2, an inlet filter 31, an outlet filter 32, a third filter 33, a defrost four-way valve 41, a heating four-way valve 42, a defrost side outdoor heat exchanger 51, a heating side outdoor heat exchanger 52, a defrost compressor 61, a heating compressor 62, a defrost side gas-liquid separator 71, a heating side gas-liquid separator 72, a defrost side oil separator 81, a heating side oil separator 82, a one-way valve 9 and a capillary tube 10.

[0026] Reference Figure 1 , four (four in this embodiment, or other numbers) indoor units 1 are arranged in parallel, and the defrosting system 100 and the heating system 200 are respectively connected in parallel with each indoor unit 1.

[0027] The heating system 200 includes a heating side outdoor heat exchanger 52, a heating four-way valve 42, a heating side gas-liquid separator 72, a heating compressor 62, and a heating side oil separator 82. The low-temperature refrigerant flowing out of the outlet of each indoor unit 1 is connected to the inlet of the heating side outdoor heat exchanger 52 through a pipeline, the outlet of the heating side outdoor heat exchanger 52 is connected to the heating four-way valve 42C port, the heating four-way valve 42S port is connected to the inlet of the heating side gas-liquid separator 72, the outlet of the heating side gas-liquid separator 72 is connected to the suction port of the heating compressor 62 through a pipeline, the exhaust port of the heating compressor 62 discharges the high-temperature refrigerant and is connected to the heating side oil separator 82, the heating side oil separator 82 is connected to the heating four-way valve 42D port through a pipeline, and the heating four-way valve 42E port is connected to the inlet of each indoor unit 1 through a pipeline;

[0028] like Figure 1 , 2 As shown, Figure 2 The specific structure of the defrost system 100 is shown in the figure. The heating system 200 also adopts the same structure (only the label names are inconsistent). The defrost system 100 includes a defrost four-way valve 41, a defrost side gas-liquid separator 71, a defrost compressor 61, a defrost side oil separator 81 and a defrost side outdoor heat exchanger 51. The high-temperature refrigerant flowing out from the heating four-way valve 42E port is also connected to the defrost four-way valve 41E port through a pipeline, the defrost four-way valve 41S port is connected to the inlet of the defrost side gas-liquid separator 71, the defrost side gas-liquid separator 71 outlet is connected to the defrost compressor 61 suction port through a pipeline, the defrost compressor 61 exhaust port is connected to the defrost side oil separator 81, the defrost side oil separator 81 is connected to the defrost four-way valve 41D port through a pipeline, the defrost four-way valve 41C port is connected to the inlet of the defrost side outdoor heat exchanger 51, after heat exchange, the low-temperature refrigerant discharged from the outlet of the defrost side outdoor heat exchanger 51 is connected to the inlet of the heating side outdoor heat exchanger 52 through a pipeline, forming a complete refrigerant flow cycle.

[0029] Preferably, during defrosting, the defrost system 100 operates at a lower frequency and the heating system 200 operates at a higher frequency to ensure that sufficient refrigerant is provided to both the defrost unit (defrost system 100) and the indoor unit (heating system).

[0030] Furthermore, an electronic expansion valve assembly is connected to the outlet pipe of the defrosting side outdoor heat exchanger 51 and the inlet pipe of the heating side outdoor heat exchanger 52, and the electronic expansion valve assembly includes an electronic expansion valve 2 and a check valve 9 connected in parallel. An outlet filter 32 is also provided on the outlet pipe of the defrosting side outdoor heat exchanger 51, and an inlet filter 31 is also provided on the inlet pipe of the heating side outdoor heat exchanger 52; the defrosting four-way valve 41E port is connected to an inlet filter 31, and the heating four-way valve 42E port is connected to an outlet filter 32.

[0031] Preferably, a branch is provided on the connection pipeline between the defrost side gas-liquid separator 71 and the defrost compressor 61 to bypass the defrost side oil separator 81, and a branch is also provided on the connection pipeline between the heating side gas-liquid separator 72 and the heating compressor 62 to bypass the heating side oil separator 82, and the two branches are connected with a capillary tube 10 and a third filter 33. The oil drain ports of both the defrost compressor 61 and the heating compressor 62 are bypassed to the corresponding exhaust ports through the pipeline. A one-way valve 9 is provided on the pipeline between the defrost side oil separator 81 and the defrost four-way valve 41D port, and a one-way valve 9 is also provided on the pipeline between the heating side oil separator 82 and the heating four-way valve 42D port. An electronic expansion valve 2 is provided on the outlet pipeline of each indoor unit 1.

[0032] In this parallel system, the defrost system 100 and the heating system 200 back up each other, and the circulation flow mode of the refrigerant is adjusted by the different flow directions of the defrost four-way valve 41 and the heating four-way valve 42. That is, after switching the four-way valve, the original defrost system 100 can be used as a new heating system, and the original heating system 200 can be used as a new defrost system.

[0033] The working process of this utility model:

[0034] When defrosting and heating are running synchronously, the unit that needs to be defrosted will be exhausted by the high-temperature and high-pressure refrigerant of this system through the corresponding compressor, and then flow to the outdoor heater for defrosting after passing through the four-way valve. At the same time, the unit system that does not need to be defrosted (i.e. the heating system) continues to be exhausted by the high-temperature and high-pressure refrigerant of the non-defrosting system through the corresponding compressor, and then pass through the four-way valve to the indoor unit to provide heat to the indoor unit, ensuring that the indoor unit can continue to heat. Since the indoor unit heats continuously, the heating effect is continuous and good, ensuring that the indoor temperature fluctuates little, which can effectively improve the user experience.

[0035] It is understandable that, for those skilled in the art, any equivalent replacement or change to the technical solution and the concept of the utility model should fall within the protection scope of the claims attached to the utility model.

Claims

1. A multi-connection parallel system for defrosting without stopping indoor fans, characterized in that: The invention comprises a plurality of indoor units (1) arranged in parallel, and a defrosting system (100) and a heating system (200) respectively connected in parallel with each indoor unit (1). The heating system (200) comprises a heating side outdoor heat exchanger (52), a heating four-way valve (42), a heating side gas-liquid separator (72), a heating compressor (62) and a heating side oil separator (82); the low-temperature refrigerant flowing out of the outlet of each indoor unit (1) is connected to the inlet of the heating side outdoor heat exchanger (52) through a pipeline; the outlet of the heating side outdoor heat exchanger (52) is connected to the C port of the heating four-way valve (42); the S port of the heating four-way valve (42) is connected to the inlet of the heating side gas-liquid separator (72); the outlet of the heating side gas-liquid separator (72) is connected to the air intake port of the heating compressor (62) through a pipeline; the exhaust port of the heating compressor (62) discharges the high-temperature refrigerant and is connected to the heating side oil separator (82); the heating side oil separator (82) is connected to the D port of the heating four-way valve (42) through a pipeline; and the E port of the heating four-way valve (42) is connected to the inlet of each indoor unit (1) through a pipeline; The defrost system (100) includes a defrost four-way valve (41), a defrost side gas-liquid separator (71), a defrost compressor (61), a defrost side oil separator (81) and a defrost side outdoor heat exchanger (51). The high-temperature refrigerant flowing out of the E port of the heating four-way valve (42) is also connected to the E port of the defrost four-way valve (41) through a pipeline. The S port of the defrost four-way valve (41) is connected to the inlet of the defrost side gas-liquid separator (71), and the outlet of the defrost side gas-liquid separator (71) is connected to the defrost side gas-liquid separator (71) through a pipeline. The compressor (61) suction port and the defrost compressor (61) exhaust port are connected to the defrost side oil separator (81), the defrost side oil separator (81) is connected to the defrost four-way valve (41) D port through a pipeline, and the defrost four-way valve (41) C port is connected to the defrost side outdoor heat exchanger (51) inlet. After heat exchange, the low-temperature refrigerant discharged from the defrost side outdoor heat exchanger (51) outlet is connected to the heating side outdoor heat exchanger (52) inlet through a pipeline, forming a whole refrigerant flow cycle; The defrosting system (100) operates at a low frequency, and the heating system (200) operates at a high frequency, to ensure sufficient refrigerant.

2. The multi-connection parallel system for defrosting without stopping the indoor fans according to claim 1, characterized in that: The outlet pipeline of the defrosting side outdoor heat exchanger (51) and the inlet pipeline of the heating side outdoor heat exchanger (52) are both connected to an electronic expansion valve assembly, and the electronic expansion valve assembly includes an electronic expansion valve (2) and a one-way valve (9) connected in parallel.

3. The multi-connection parallel system for defrosting without stopping indoor fans according to claim 2, characterized in that: An outlet filter (32) is also provided on the outlet pipeline of the outdoor heat exchanger (51) on the defrosting side, and an inlet filter (31) is also provided on the inlet pipeline of the outdoor heat exchanger (52) on the heating side; the E port of the defrosting four-way valve (41) is connected to an inlet filter (31), and the E port of the heating four-way valve (42) is connected to an outlet filter (32).

4. The multi-connection parallel system for defrosting without stopping indoor fans according to claim 1, characterized in that: A branch is provided on the connecting pipeline between the defrost side gas-liquid separator (71) and the defrost compressor (61) to bypass and connect to the defrost side oil separator (81); a branch is also provided on the connecting pipeline between the heating side gas-liquid separator (72) and the heating compressor (62) to bypass and connect to the heating side oil separator (82); both branches are connected to a capillary tube (10) and a third filter (33).

5. The multi-connection parallel system for defrosting without stopping indoor fans according to claim 1, characterized in that: The oil drain ports of both the defrosting compressor (61) and the heating compressor (62) are connected to the corresponding exhaust ports through pipeline bypass.

6. The multi-connection parallel system for defrosting without stopping indoor fans according to claim 1, characterized in that: A one-way valve (9) is arranged on the pipeline between the defrosting side oil separator (81) and the D port of the defrosting four-way valve (41), and a one-way valve (9) is also arranged on the pipeline between the heating side oil separator (82) and the D port of the heating four-way valve (42).

7. The multi-connection parallel system for defrosting without stopping indoor fans according to claim 1, characterized in that: An electronic expansion valve (2) is arranged on the outlet pipeline of each indoor unit (1).

8. The multi-connection parallel system for defrosting without stopping indoor fans according to any one of claims 1 to 7, characterized in that: The defrosting system (100) and the heating system (200) serve as backup for each other, and the circulation flow of the refrigerant is adjusted by means of different flow directions of the defrosting four-way valve (41) and the heating four-way valve (42).

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