# US 11,906,221 B2 · Defrosting control method of multifunctional multi-split system with double four-way valves

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- Number: US 11,906,221 B2
- Document ID: US11906221B2
- Status: Granted
- Kind: B2
- Application number: 17/564,333
- Filed: 2021-12-29
- Published: 2022-06-30
- Granted: 2024-02-20
- Earliest claimed: 2021-12-29
- Assignees: Guangdong Giwee Technology Co. Ltd.
- Applicants: Guangdong Giwee Technology Co. Ltd.
- Inventors: Min Zhou; Hongbin Liu
- Web page: https://patentgrep.com/patent/US11906221B2

## CPC

- F25B 47/025: {by reversing the cycle}
- F24F 11/42: of outdoor units
- F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02)
- F25B 41/20: Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31)
- F25B 41/345: by solenoids
- F25B 43/02: for separating lubricants from the refrigerant
- F25B 41/24: Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
- F25B 2313/003: Indoor unit with water as a heat sink or heat source
- F25B 2313/007: three pipes connecting the outdoor side to the indoor side with multiple indoor units
- F25B 2313/0231: with simultaneous cooling and heating
- F25B 2313/02742: using two four-way valves
- F25B 2600/2513: Expansion valves
- F25B 2600/2515: Flow valves
- F25B 2600/2519: On-off valves
- Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A defrosting control method of a multi-functional multi-split system with double four-way valves. The multi-functional multi-split system includes an outdoor unit, at least one set of hydraulic modules, and at least one set of indoor modules. When the multi-split system is switched from a normal operation mode to a defrosting mode, a first four-way valve and a second four-way valve are powered down, and operation modes of each set of indoor modules and each set of hydraulic modules, the on/off state of fans of an indoor heat exchanger and a hydraulic heat exchanger, opening degrees of a first electromagnetic valve of the indoor heat exchanger and a second electromagnetic valve of the hydraulic heat exchanger, and the on/off state of the first electromagnetic valve and the second electromagnetic valve are correspondingly adjusted based on the previous operation modes of each set of indoor modules and each set of hydraulic modules.

## Claims

### Claim 1

A defrosting control method of a multi-functional multi-split system with double four-way valves, the multi-split system comprising:
an outdoor unit (100),
at least one set of hydraulic modules (200),
at least one set of indoor modules (300),
a liquid pipe (7),
a high-low pressure gas pipe (8), and
a high-pressure gas pipe (9),
wherein the outdoor unit (100) comprises a compressor (1), a first four-way valve (2), a second four-way valve (3), and an outdoor heat exchanger (4),
wherein an output end of the compressor (1) is respectively connected to port D of the first four-way valve (2) and port D of the second four-way valve (3), an input end of the compressor (1) is respectively connected to port S of the first four-way valve (2) and port S of the second four-way valve (3), port E of the first four-way valve (2) is connected to port S of the second four-way valve (3) via a throttling unit, port C of the second four-way valve (3) is connected to port S of the first four-way valve (2) via a throttling unit, and port C of the first four-way valve (2) is connected to the outdoor heat exchanger (4);
wherein one end of the liquid pipe (7) is connected to the outdoor heat exchanger (4), and the other end of the liquid pipe (7) is respectively connected to the other end of a hydraulic heat exchanger (10) of each set of hydraulic modules (200) and the other end of an indoor heat exchanger (11) of each set of indoor modules (300);
wherein one end of the high-pressure gas pipe (9) is connected between the four-way valves and the output end of the compressor (1) by bypassing, and the other end of the high-pressure gas pipe (9) is connected to one end of the hydraulic heat exchanger (10) of each set of hydraulic modules (200);
wherein one end of the high-low pressure gas pipe (8) is connected to port E of the second four-way valve (3), and the other end of the high-low pressure gas pipe (8) is respectively connected to one end of the hydraulic heat exchanger (10) of each set of hydraulic modules (200) and one end of the indoor heat exchanger (11) of each set of indoor modules (300);
wherein a first electronic expansion valve (12) is arranged between the liquid pipe (7) and each hydraulic heat exchanger (10) and each indoor heat exchanger (11);
wherein a first electromagnetic valve (13) is arranged between the high-pressure gas pipe (9) and any one of the hydraulic heat exchangers (10);
wherein a second electromagnetic valve (14) is arranged between the high-low pressure gas pipe (8) and any one of the hydraulic heat exchangers (10);
the method comprising, when the multi-split system is switched from a normal operation mode to a defrosting mode, the first four-way valve (2) and the second four-way valve (3) are powered down, and operation modes of each set of indoor modules (300) and each set of hydraulic modules (200), the on/off state of fans of the indoor heat exchangers (11) and the hydraulic heat exchangers (10), opening degrees of the first electronic expansion valves (12) of the indoor heat exchangers (11) and the first electronic expansion valves (12) of the hydraulic heat exchangers (10), and the on/off state of the first electromagnetic valves (13) and the second electromagnetic valves (14) are correspondingly adjusted based on the previous operation modes of each set of indoor modules (300) and each set of hydraulic modules (200);
wherein when the first four-way valve (2) is powered down, the first port (D) thereof is in communication with the fourth port (C), and the third port (E) is in communication with the second port (S) and, when the second four way valve (3) is power down, the first port (D) thereof is in communication with the third port (C), and the fourth port (E) is in communication with the second port (S); and
wherein the adjusting comprises:
adjusting the first expansion valve (12) of each set of indoor modules (300) previously in an operating mode to a maximum opening degree;
each indoor module previously in an off state remaining off;
turning off the first electromagnetic valve (13), the second electromagnetic valve (14), and the first electronic expansion vale (12) of each set of hydraulic modules (200) previously in an off state; and
switching each set of hydraulic modules (200) previously in a water heating mode to a water refrigeration mode, and turning on the first electromagnetic vale 913) thereof, turning off the second electromagnetic valve (14) thereof, and adjusting the first electronic expansion vale (12) thereof to a maximum degree opening.

### Claim 2 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, wherein when the multi-split system only has one or more sets of indoor modules (300) switched from a heating mode to the defrosting mode, the first four-way valve (2) and the second four-way valve (3) are powered down, all the indoor modules (300) are switched to a refrigeration mode for operation and the fan of each indoor heat exchanger (11) is turned off, the first electronic expansion valve (12) of each indoor heat exchanger (11) is adjusted to a maximum opening degree, the first electromagnetic valves (13) and the second electromagnetic valves (14) of all the hydraulic modules (200) are turned off, and the first electronic expansion valves (12) of all the hydraulic heat exchangers (10) are turned off.

### Claim 3 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, wherein when the multi-split system only has one or more sets of hydraulic modules (200) switched from a water heating mode to the defrosting mode, the first four-way valve (2) and the second four-way valve (3) are powered down, each set of indoor modules (300) previously in an off state remains off, each set of indoor modules (300) previously in an air supply state remains the on state of its fan and the first electronic expansion valve (12) of the indoor heat exchanger (11) thereof is adjusted to a maximum opening degree; the first electromagnetic valve (13), the second electromagnetic valve (14), and the first electronic expansion valve (12) of each set of hydraulic modules (200) previously in an off state are turned off; each set of hydraulic modules (200) previously in the water heating mode is switched to a water refrigeration mode, and the first electromagnetic valve (13) thereof is turned on, the second electromagnetic valve (14) thereof is turned off, and the first electronic expansion valve (12) thereof is adjusted to a maximum opening degree.

### Claim 4 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, wherein when the multi-split system has one or more sets of indoor modules (300) switched from a heating mode to the defrosting mode and one or more sets of hydraulic modules (200) switched from a water heating mode to the defrosting mode, the first four-way valve (2) and the second four-way valve (3) are powered down, each set of indoor modules (300) previously in an off state remains off, each set of indoor modules (300) previously in the heating mode has its fan turned off and the first electronic expansion valve (12) thereof is adjusted to a maximum opening degree; the first electromagnetic valve (13), the second electromagnetic valve (14), and the first electronic expansion valve (12) of each set of hydraulic modules (200) previously in an off state are turned off; each set of hydraulic modules (200) previously in the water heating mode is switched to a water refrigeration mode, and the first electromagnetic valve (13) thereof is turned on, the second electromagnetic valve (14) thereof is turned off, and the first electronic expansion valve (12) thereof is adjusted to a maximum opening degree.

### Claim 5 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, wherein when the multi-split system has one or more sets of indoor modules (300) switched from a refrigeration mode to the defrosting mode and one or more sets of hydraulic modules (200) switched from a water heating mode to the defrosting mode, the first four-way valve (2) and the second four-way valve (3) are powered down, each set of indoor modules (300) previously in an off state remains off, each set of indoor modules (300) previously in an air supply state and the refrigeration mode remains the on state of its fan and the first electronic expansion valve (12) of the indoor heat exchanger (11) thereof is adjusted to a maximum opening degree; the first electromagnetic valve (13), the second electromagnetic valve (14), and the first electronic expansion valve (12) of each set of hydraulic modules (200) previously in an off state are turned off; each set of hydraulic modules (200) previously in the water heating mode is switched to a water refrigeration mode, and the first electromagnetic valve (13) thereof is turned on, the second electromagnetic valve (14) thereof is turned off, and the first electronic expansion valve (12) thereof is adjusted to a maximum opening degree.

### Claim 6 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, further comprising: an oil separator (5) arranged at the output end of the compressor (1).

### Claim 7 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, further comprising: a gas-liquid separator (6) arranged at the input end of the compressor (1).

### Claim 8 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, comprising: at least two compressors (1) arranged in parallel.

### Claim 9 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, wherein an outdoor unit electronic expansion valve is arranged at one end of the liquid pipe (7) adjacent to the outdoor heat exchanger (4).

### Claim 10 (depends on 1)

The defrosting control method of a multi-functional multi-split system with double four-way valves according to claim 1, wherein the high-low pressure gas pipe (8) is connected to one end of the hydraulic heat exchanger (10) and the indoor heat exchanger (11) through a branch pipe, and the liquid pipe (7) is respectively connected to the hydraulic heat exchanger (10) and the indoor heat exchanger (11).