CN118168178A

CN118168178A - Heat pump air conditioning system and operation method thereof

Info

Publication number: CN118168178A
Application number: CN202410371938.8A
Authority: CN
Inventors: 毕志书; 李梁; 彭晓阳; 吴腾腾
Original assignee: Jiangsu Jinbitian System Integration Co ltd
Current assignee: Jiangsu Jinbitian System Integration Co ltd
Priority date: 2024-03-29
Filing date: 2024-03-29
Publication date: 2024-06-11

Abstract

The invention discloses a heat pump air conditioning system and an operation method thereof.A first compressor is connected with a second compressor through a stop valve, and the second compressor is connected with a liquid separation heat exchanger through a four-way reversing valve; the light component outlet of the liquid separation heat exchanger is connected with the first expansion valve, and the heavy component outlet is connected with the second expansion valve; the first expansion valve is connected with the first flash tank, and the primary separation of light and heavy components is realized by adopting a liquid separation heat exchanger; the light and heavy components subjected to preliminary separation are subjected to multistage separation again through a two-stage flash tank, so that the temperature sliding effect is improved; the whole device adopts a double flash tank, so that the light and heavy components in the non-azeotropic coolant are subjected to multistage separation; the air injection enthalpy-increasing technology is adopted, so that the adaptability of the air conditioning system in a low-temperature environment is improved; the number of compressors is controlled according to the operation control logic, so that multi-stage starting is realized, and energy is saved.

Description

Heat pump air conditioning system and operation method thereof

Technical Field

The invention belongs to the technical field of air conditioning systems, and particularly relates to a heat pump air conditioning system and an operation method thereof.

Background

As a core working medium in the operation process of the air conditioner, an air conditioner refrigerant has been developed from the first generation to the fourth generation. Compared with the former two generations, the third generation refrigerant is a hydrofluorocarbon refrigerant, does not contain chlorine element, has no damage to an ozone layer, has a stronger climate warming effect and aggravates the greenhouse effect. The fourth generation refrigerant is hydrocarbon fluoride refrigerant, and compared with the third generation refrigerant, the fourth generation refrigerant has no damage to the ozone layer and almost has no climate warming effect.

The main air-conditioning refrigerants in the China market are the third generation refrigerants, mainly R32 and R410A, R. China has passed the Ke-cali amendment in 2021, which states that China has been required to cut down the production and use of third generation refrigerants in recent years. The fourth-generation refrigerant which is more environment-friendly has wide application prospect.

Compared with the fourth generation pure refrigerant, such as R290 only containing propane, the fourth generation non-azeotropic refrigerant is prepared by mixing 2 or more pure refrigerants, has the temperature sliding property, can more effectively utilize a low-temperature heat source, and improves the working efficiency of the air conditioner.

When the common air source heat pump air conditioner is used in a low-temperature period in winter in a cold region and a severe cold region, the energy efficiency of the air conditioner is reduced, the indoor temperature is difficult to meet the set requirement, the frosting phenomenon of the evaporator cannot be effectively treated in time, and the air conditioner cannot be used in severe cases. Even if a non-azeotropic refrigerant is adopted in the common air-injection enthalpy-increasing heat pump air conditioner, the temperature sliding effect is poor, and the air conditioner energy efficiency is low. When the air conditioner executes heating operation under the conditions of outdoor low temperature and frosting of an evaporator, fans in part of fan coils of the air conditioner are started at the same time, so that cold air blowing at an air outlet of the air conditioner occurs in an initial heating stage.

Disclosure of Invention

The invention aims to provide a heat pump air conditioning system and an operation method thereof, so as to solve the problems.

In order to achieve the above purpose, the present invention provides the following technical solutions: the heat pump air conditioning system comprises a first compressor, a stop valve, a second compressor, a four-way reversing valve, a liquid separation heat exchanger, a water pump, a water supply temperature sensor, a fan coil, a backwater temperature sensor, a first control valve, a first expansion valve, a first flash tank, a second control valve, a second expansion valve, a second flash tank, a third expansion valve, an outdoor heat exchanger, a fan, a three-way valve, an indoor air conditioning area, an air conditioning data processing center, an indoor data acquisition control center and an outdoor data acquisition control center;

The first compressor is connected with the second compressor through a stop valve, and the second compressor is connected with the liquid separation heat exchanger through a four-way reversing valve; the light component outlet of the liquid separation heat exchanger is connected with the first expansion valve, and the heavy component outlet is connected with the second expansion valve; the first expansion valve is connected with the first flash tank, the light component outlet of the first flash tank is connected with the first control valve, and the heavy component outlet of the first flash tank is connected with the second control valve; the second expansion valve and the second control valve are connected with the second flash tank; the light component outlet of the second flash tank is connected with the first control valve, and the heavy component outlet is connected with the third expansion valve; the first control valve is connected with the second compressor; the outdoor heat exchanger is matched with the fan and used for acquiring heat or cold in the air; the third expansion valve is connected with the four-way reversing valve through the outdoor heat exchanger, the four-way reversing valve is connected with the e end of the three-way valve, the f end of the three-way valve is connected with the first compressor, and the g end of the three-way valve is directly connected with the second compressor.

Preferably, the air conditioner data processing center comprises a data storage module, a data analysis processing module, a rule base module and a command sending module.

Preferably, the indoor data acquisition control center comprises an indoor information uploading module, an indoor command receiving module, an indoor temperature and humidity monitoring module, an indoor unit operation information acquisition module, a user command receiving module and an indoor unit operation state control module.

Preferably, the outdoor data acquisition control center comprises an outdoor information uploading module, an outdoor unit command receiving module, an outdoor temperature and humidity monitoring module, an outdoor heat exchanger frosting monitoring module, an outdoor unit operation information acquisition module and an outdoor unit operation state control module.

Preferably, the first compressor and the second compressor are variable frequency compressors; the first expansion valve, the second expansion valve and the third expansion valve are electronic throttling expansion valves, and the opening degree can be adjusted; the first control valve, the second control valve and the three-way valve are all controlled by electromagnetism; the water pump is a variable-frequency regulating pump, and the motor is preferably a permanent magnet synchronous motor.

The operation method of the heat pump air conditioning system comprises the following specific steps:

Step S0: the air conditioning system is in a shutdown state and starts the flow;

Step S1: judging whether the air conditioner user instruction receiving module receives a user starting instruction, if the air conditioner system receives the starting instruction, entering a step S2, otherwise returning to the step S0;

Step S2: the indoor temperature and humidity monitoring module, the outdoor temperature and humidity monitoring module and the frosting monitoring module of the outdoor heat exchanger of the air conditioner are used for data acquisition and are respectively uploaded to the air conditioner data processing center through the indoor information uploading module and the outdoor information uploading module; at this time, the air conditioner is in a standby state. Then, the process proceeds to step S3;

Step S3: judging whether an air conditioner user instruction receiving module receives a heating or refrigerating instruction of a user or not; if the air conditioning system receives a heating or refrigerating instruction of a user, the step S3 is entered, otherwise, the step S3 is returned to;

step S4: the air conditioner data processing center invokes frosting coverage rate data of the surface of the outdoor heat exchanger at the latest moment, judges whether the frosting coverage rate exceeds a limit value, if so, enters a step S5, otherwise, enters a step S8;

step S5: judging whether the air conditioner meets the strong defrosting mode condition, if so, entering a step 6, otherwise, entering a step S7;

Step S6: the air conditioning system performs a strong defrost mode, as shown in fig. 4; returning to step S4;

step S7: the air conditioning system performs a weak defrosting mode; returning to step S4;

step S8: judging whether the heating or cooling instruction received by the user instruction receiving module is a heating instruction or not; if yes, entering a step S9, otherwise entering a step S20;

step S9: judging whether the indoor temperature TN is less than or equal to the air conditioning temperature TS set by a user; if TN is less than or equal to TS, the step S10 is carried out, otherwise, the step S16 is carried out;

step S10: the air conditioning system executes the max running state under the weak heating mode for 0-30 minutes; then, the process proceeds to step S11;

step S11: in the step S10, continuously running for 0-30 minutes, judging whether the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by a user minus a temperature value of 0.5 ℃, or if the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by the user minus a temperature value of 0.2 ℃ under the assumption that the step S10 continuously runs for 45 minutes; if TN is more than or equal to TS-0.5 ℃ or, entering a step S12, otherwise entering a step S13;

step S12: the air conditioning system executes an energy-saving running state under a weak heating mode; then, the process proceeds to step S31;

Step S13: judging whether the continuous operation time tS10 of the step S10 is within 30 minutes or not; if 0.ltoreq.tS10.ltoreq.30min, returning to step S10; if tS10>30min, go to step S14;

Step S14: executing a max running state under a forced heating mode for 0-30 minutes; then, the process proceeds to step S15;

Step S15: in the step S14, continuously running for 0-30 minutes, judging whether the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by a user minus a temperature value of 0.5 ℃, or if the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by the user minus a temperature value of 0.2 ℃ under the assumption that the step S14 continuously runs for 45 minutes, judging whether the limit convergence value of the indoor temperature TN within 45 minutes is larger than or equal to the limit convergence value of the indoor temperature TN within the 45 minutes. If TN is more than or equal to TS-0.5 ℃ or, entering step S16, otherwise returning to step S14;

step S16: and executing the energy-saving operation state in the forced hot mode. Then, the process proceeds to step S31;

Step S17: judging whether the indoor temperature TN is larger than or equal to the air-conditioning temperature TS set by a user plus a temperature value of 5 ℃, and simultaneously judging whether the indoor temperature TN is smaller than or equal to the outdoor temperature TW; if yes, go to step S18, otherwise go to step S19;

Step S18: the air conditioning system performs a weak cooling mode; then returns to step S9;

step S19: the air conditioner executes a blowing mode; and then returns to step S9.

Step S20: and judging whether the indoor temperature TN is greater than or equal to the air conditioning temperature TS set by a user. If TN is more than or equal to TS, entering step S21, otherwise entering step S28;

Step S21: the air conditioning system executes the max running state in the weak refrigeration mode for 0-30 minutes. Then, the process proceeds to step S22;

Step S22: in the step S21, continuously running for 0-30 minutes, judging whether the indoor temperature TN is smaller than or equal to the air conditioning temperature TS set by a user plus a temperature value of 0.5 ℃, or if the indoor temperature TN is smaller than or equal to the air conditioning temperature TS set by the user plus a temperature value of 0.2 ℃ under the assumption that the step S21 continuously runs for 45 minutes; if TN is less than or equal to TS+0.5deg.C or the temperature is lower than or equal to TS+0.5deg.C, the step S23 is performed, otherwise the step S24 is performed;

step S23, the air conditioning system executes an energy-saving running state in a weak refrigeration mode; then, the process proceeds to step S31;

Step S24: judging whether the continuous operation time tS21 of the step S21 is within 30 minutes or not; if 0.ltoreq.tS21.ltoreq.30min, returning to step S21; if tS21>30min, go to step S25;

step S25: executing a max running state in a strong refrigeration mode, wherein the time is 0-30 minutes; then, the process proceeds to step S26;

step S26: in the step S25, continuously running for 0-30 minutes, judging whether the indoor temperature TN is smaller than or equal to the air conditioning temperature TS set by a user plus a temperature value of 0.5 ℃, or if the indoor temperature TN is smaller than or equal to the air conditioning temperature TS set by the user plus a temperature value of 0.2 ℃ under the assumption that the step S25 continuously runs for 45 minutes; if TN is less than or equal to TS+0.5deg.C or the temperature is lower than or equal to TS+0.5deg.C, the step S27 is performed, otherwise the step S25 is performed;

Step S27: executing an energy-saving running state in a strong refrigeration mode; then, the process proceeds to step S31;

Step S28: judging whether the indoor temperature TN is less than or equal to the air conditioning temperature TS set by a user minus a temperature value of 5 ℃, and simultaneously judging whether the indoor temperature TN is greater than or equal to the outdoor temperature TW; if yes, go to step S29, otherwise go to step S30;

step S29: the air conditioning system executes a weak heating mode; then returns to step S20;

step S30: the air conditioning system executes a windless mode; then returns to step S20;

step S31: judging whether the user instruction receiving module 4025 receives a shutdown instruction of a user, if so, entering a step S32, otherwise, entering a step S8;

step S32: executing a shutdown command by the air conditioning system; then, the process proceeds to step S0.

The invention has the technical effects and advantages that: the patent is not limited to be used in an air source heat pump system, an outdoor heat exchanger and a fan in the system can be replaced by an underground heat exchanger of a ground source heat pump and a water source system, and the outdoor heat exchanger in the system can be replaced by a cooling tower for heat exchange; the fan coil in the indoor air conditioning unit area can be used for running a coolant besides water in the pipeline to prepare a split fluorine system air conditioner;

The liquid separation heat exchanger is adopted to realize the primary separation of light and heavy components; the light and heavy components subjected to preliminary separation are subjected to multistage separation again through a two-stage flash tank, so that the temperature sliding effect is improved; according to the severe outdoor winter conditions, part of the light-component coolant can be directly led into the second compressor without passing through the outdoor heat exchanger, so that the indoor condition temperature is improved;

The whole device adopts a double flash tank, so that the light and heavy components in the non-azeotropic coolant are subjected to multistage separation; the air injection enthalpy-increasing technology is adopted, so that the adaptability of the air conditioning system in a low-temperature environment is improved; the number of compressors is controlled according to the operation control logic, so that multi-stage starting is realized, and energy is saved.

Drawings

FIG. 1 is a diagram of an air conditioning system according to the present invention;

FIG. 2 is a control diagram of the operation of the air conditioning system of the present invention;

FIG. 3 is a forced heat pattern diagram of an air conditioning system according to the present invention;

FIG. 4 is a diagram of a strong defrost mode for an air conditioning system according to the present invention;

FIG. 5 is a diagram of a strong cooling mode of the air conditioning system of the present invention;

Fig. 6 is a logic diagram of an air conditioning system operation control according to the present invention.

In the figure: the first compressor 201, the stop valve 202, the second compressor 203, the four-way reversing valve 204, the liquid-separating heat exchanger 205, the water pump 206, the water supply temperature sensor 207, the fan coil 208, the backwater temperature sensor 209, the first control valve 210, the first expansion valve 211, the first flash tank 212, the second control valve 213, the second expansion valve 214, the second flash tank 215, the third expansion valve 216, the outdoor heat exchanger 217, the fan 218, the three-way valves 219 and 301 are an indoor air conditioning area, an air conditioning data processing center 401, an indoor data acquisition control center 402 and an outdoor data acquisition control center 403;

A data storage module 4011, a data analysis processing module 4012, a rule base module 4013, and a command transmission module 4014;

An indoor information uploading module 4021, an indoor command receiving module 4022, an indoor temperature and humidity monitoring module 4023, an indoor unit operation information acquisition module 4024, a user command receiving module 4025 and an indoor unit operation state control module 4026;

the outdoor unit comprises an outdoor information uploading module 4031, an outdoor unit command receiving module 4032, an outdoor temperature and humidity monitoring module 4033, an outdoor heat exchanger frosting monitoring module 4034, an outdoor unit operation information acquisition module 4035 and an outdoor unit operation state control module 4036.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a heat pump air conditioning system as shown in the figure, which comprises a first compressor 201, a stop valve 202, a second compressor 203, a four-way reversing valve 204, a liquid separation heat exchanger 205, a water pump 206, a water supply temperature sensor 207, a fan coil 208, a backwater temperature sensor 209, a first control valve 210, a first expansion valve 211, a first flash tank 212, a second control valve 213, a second expansion valve 214, a second flash tank 215, a third expansion valve 216, an outdoor heat exchanger 217, a fan 218, a three-way valve 219, an indoor air conditioning area 301, an air conditioning data processing center 401, an indoor data acquisition control center 402 and an outdoor data acquisition control center 403;

The first compressor 201 is connected with the second compressor 203 through a stop valve 202, and the second compressor 203 is connected with a liquid-separating heat exchanger 205 through a four-way reversing valve 204; the light component outlet of the liquid-separating heat exchanger 205 is connected with a first expansion valve 211, and the heavy component outlet is connected with a second expansion valve 214; the first expansion valve 211 is connected with the first flash tank 212, the light component outlet of the first flash tank 212 is connected with the first control valve 210, and the heavy component outlet of the first flash tank 212 is connected with the second control valve 213; the second expansion valve 214 and the second control valve 213 are connected to the second flash tank 215; the light fraction outlet of the second flash tank 215 is connected to the first control valve 210 and the heavy fraction outlet is connected to the third expansion valve 216; the first control valve 210 is connected to the second compressor 203; the outdoor heat exchanger 217 is matched with the fan 218 and used for acquiring heat or cold in the air; the third expansion valve 216 is connected to the four-way selector valve 204 through the outdoor heat exchanger 217, the four-way selector valve 204 is connected to the e-terminal of the three-way valve 219, the f-terminal of the three-way valve 219 is connected to the first compressor 201, and the g-terminal of the three-way valve 219 is directly connected to the second compressor 203.

Specifically, the air-conditioning data processing center 401 includes a data storage module 4011, a data analysis processing module 4012, a rule base module 4013, and a command sending module 4014.

Specifically, the indoor data acquisition control center 402 includes an indoor information uploading module 4021, an indoor command receiving module 4022, an indoor temperature and humidity monitoring module 4023, an indoor unit operation information acquisition module 4024, a user command receiving module 4025, and an indoor unit operation state control module 4026.

Specifically, the outdoor data acquisition control center 403 includes an outdoor information uploading module 4031, an outdoor unit command receiving module 4032, an outdoor temperature and humidity monitoring module 4033, an outdoor heat exchanger frosting monitoring module 4034, an outdoor unit operation information acquisition module 4035, and an outdoor unit operation state control module 4036.

Specifically, the first compressor 201 and the second compressor 203 are variable frequency compressors; the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 are all electronic throttling expansion valves, and the opening degree can be adjusted; the first control valve 210, the second control valve 213, and the three-way valve 219 are all electromagnetically controlled; the water pump 206 is a variable frequency regulating pump, and the motor is preferably a permanent magnet synchronous motor.

step S1: judging whether the air conditioner user instruction receiving module 4025 receives a user starting instruction, if the air conditioner system receives the starting instruction, entering a step S2, otherwise returning to the step S0;

Step S2: the indoor temperature and humidity monitoring module 4023 of the air conditioner collects indoor temperature and humidity data once every 1 minute, and the indoor temperature and humidity data is uploaded to the air conditioner data processing center 401 through the indoor information uploading module 4021; the outdoor temperature and humidity monitoring module 4033 of the air conditioner collects indoor temperature and humidity data once every 1 minute, and the indoor temperature and humidity data are uploaded to the air conditioner data processing center 401 through the outdoor information uploading module 4031. The frosting coverage rate of the surface of the outdoor heat exchanger 217 is collected by the outdoor heat exchanger frosting monitoring module 4034 every 1 minute, and is uploaded to the air-conditioning data processing center 401 through the outdoor information uploading module 4031. At this time, the air conditioner is in a standby state. Then, the process proceeds to step S3;

Step S3: whether the air conditioner user instruction receiving module 4025 receives a heating or cooling instruction of a user is determined. If the air conditioning system receives a heating or refrigerating instruction of a user, the step S3 is entered, otherwise, the step S3 is returned to;

Step S4: the air-conditioning data processing center 401 retrieves the frosting coverage rate data of the surface of the outdoor heat exchanger 217 at the latest moment, judges whether the frosting coverage rate exceeds a limit value, if so, enters a step S5, otherwise, enters a step S8;

step S6: the air conditioning system performs a strong defrost mode, as shown in fig. 4. Returning to step S4;

step S7: the air conditioning system performs a weak defrost mode. Returning to step S4;

Step S8: the heating or cooling instruction received by the user instruction receiving module 4025 is determined, specifically, whether the heating instruction is a heating instruction. If yes, entering a step S9, otherwise entering a step S20;

Step S9: and judging whether the indoor temperature TN is less than or equal to the air conditioning temperature TS set by a user. If TN is less than or equal to TS, the step S10 is carried out, otherwise, the step S16 is carried out;

Step S10: the air conditioning system executes the max running state under the weak heating mode for 0-30 minutes. Then, the process proceeds to step S11;

step S11: and in the step S10, continuously running for 0-30 minutes, judging whether the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by a user minus a temperature value of 0.5 ℃, or if the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by the user minus a temperature value of 0.2 ℃ under the assumption that the step S10 continuously runs for 45 minutes, judging whether the limit convergence value of the indoor temperature TN within 45 minutes is larger than or equal to the limit convergence value of the indoor temperature TN within the 45 minutes. If TN is more than or equal to TS-0.5 ℃ or, entering a step S12, otherwise entering a step S13;

step S12: the air conditioning system performs an energy saving operation state in the weak heating mode. Then, the process proceeds to step S31;

step S13: it is determined whether the continuous operation time tS10 of step S10 is within 30 minutes. If 0.ltoreq.tS10.ltoreq.30min, returning to step S10; if tS10>30min, go to step S14;

step S14: and executing the max running state under the forced hot mode for 0-30 minutes. Then, the process proceeds to step S15;

Step S17: and judging whether the indoor temperature TN is larger than or equal to the air conditioning temperature TS set by a user plus a temperature value of 5 ℃, and meanwhile, judging whether the indoor temperature TN is smaller than or equal to the outdoor temperature TW. If yes, go to step S18, otherwise go to step S19;

Step S18: the air conditioning system performs a weak cooling mode. Then returns to step S9;

step S19: the air conditioner performs a blowing mode. And then returns to step S9.

step S22: in the step S21, whether the indoor temperature TN is smaller than or equal to the air conditioning temperature TS set by the user plus a temperature value of 0.5 ℃ is judged in 0-30 minutes or whether the limit convergence value of the indoor temperature TN in 45 minutes is smaller than or equal to the air conditioning temperature TS set by the user plus a temperature value of 0.2 ℃ is judged on the assumption that the step S21 is continuously operated for 45 minutes. If TN is less than or equal to TS+0.5deg.C or the temperature is lower than or equal to TS+0.5deg.C, the step S23 is performed, otherwise the step S24 is performed;

Step S23, the air conditioning system executes the energy-saving operation state in the weak refrigeration mode. Then, the process proceeds to step S31;

step S24: it is determined whether the continuous operation time tS21 of step S21 is within 30 minutes. If 0.ltoreq.tS21.ltoreq.30min, returning to step S21; if tS21>30min, go to step S25;

step S25: and executing the max running state in the strong refrigeration mode for 0-30 minutes. Then, the process proceeds to step S26;

Step S26: in the step S25, whether the indoor temperature TN is smaller than or equal to the air conditioning temperature TS set by the user plus a temperature value of 0.5 ℃ is judged in 0-30 minutes or whether the limit convergence value of the indoor temperature TN in 45 minutes is smaller than or equal to the air conditioning temperature TS set by the user plus a temperature value of 0.2 ℃ is judged on the assumption that the step S25 is continuously operated for 45 minutes. If TN is less than or equal to TS+0.5deg.C or the temperature is lower than or equal to TS+0.5deg.C, the step S27 is performed, otherwise the step S25 is performed;

step S27: and executing the energy-saving operation state in the strong refrigeration mode. Then, the process proceeds to step S31;

Step S28: and judging whether the indoor temperature TN is less than or equal to the air conditioning temperature TS set by a user minus a temperature value of 5 ℃, and meanwhile, judging whether the indoor temperature TN is greater than or equal to the outdoor temperature TW. If yes, go to step S29, otherwise go to step S30;

Step S29: the air conditioning system performs a weak heating mode. Then returns to step S20;

step S30: the air conditioning system performs a windless mode. Then returns to step S20;

step S32: the air conditioning system executes a shutdown command. Then, the process proceeds to step S0.

Further:

in the step S4, the limit value of the frosting coverage rate of the air conditioner is 5%;

In the step S5, the strong defrosting mode condition is: the frosting coverage rate of the surface of the outdoor heat exchanger 217 is more than or equal to 10 percent, or the frosting coverage rate of the surface of the outdoor heat exchanger 217 is more than 5 percent, and the temperature of the air near the surface of the outdoor heat exchanger 217 is less than or equal to minus 10 ℃;

In the above step S9, the indoor temperature TN is the indoor air temperature, and is measured by the temperature sensor in the indoor temperature and humidity monitoring module 4023. TS is the air conditioning temperature set by the user, and the instruction is received by the user instruction receiving module 4025. The indoor temperature TN is acquired and uploaded by the indoor temperature and humidity monitoring module 4023 once every 1 minute;

In the above step S10, the weak heating mode max operation state is: on the basis of the weak heating mode, the running state of the whole air conditioning system is in the maximum heating amount state. The operating frequency of the water pump 206 is 50Hz, the fan in the fan coil 208 is operated at the rated frequency, the second compressor 203 is operated at the rated frequency, the opening degrees of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 are all maximum allowable values, and the first control valve 210 is in a full-open state;

In the step S11, based on the analysis and processing of the indoor temperature TN data in the period of time corresponding to the continuous operation of the step S10 in the period of time corresponding to 0 to 30 minutes, the air conditioning data processing center 401 obtains the limit convergence value of the corresponding indoor temperature TN when the step S10 is 45 minutes, which is denoted as:

in the step S12, the weak heating mode is in an energy-saving operation state: on the basis of a weak heating mode, the absolute value of the difference between the indoor temperature TN and the air conditioner set temperature TS is ensured to be less than or equal to 0.5 ℃, namely, the operation frequency of the water pump 206 and the second compressor 203 is changed, the fan frequency in the fan coil 208 is changed, the opening degree of the first expansion valve 211, the second expansion valve 214, the third expansion valve 216 and the like are changed through the coordination of the air conditioner data processing center 401, the indoor data acquisition control center 402 and the outdoor data acquisition control center 403, so that the whole air conditioner system equipment is in a high-efficiency operation state, and the waste of the heating amount of the air conditioner is reduced.

In the above step S14, the forced thermal mode max operating state is: on the basis of the forced heating mode, the running state of the whole air conditioning system is in a state with the maximum heating capacity. The running frequency of the water pump 206 is 50Hz, the fans in the fan coil 208 run at the rated frequency, the opening degrees of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 are all maximum values allowed, the first control valve 210 is in a full-open state, and the first compressor 201 and the second compressor 203 run at the rated power;

In the above step S15, if the return to step S14 is always performed and the step S16 cannot be performed, the meaning is that: even if the air conditioning system is operated at the maximum heating amount, the indoor temperature cannot always reach the air conditioning temperature set by the user. At this time, step S15 can ensure that the air conditioning system is always operated at the maximum heating amount. The representation is: based on the state of continuously operating the step S14 and within the corresponding time period of 0-30 minutes, the air-conditioning data processing center 401 analyzes and processes the indoor temperature TN data within the time period to obtain the limit convergence value of the corresponding indoor temperature TN when the step S14 is assumed to be 45 minutes;

in the step S16, the forced hot mode energy-saving operation state is: on the basis of the forced heating mode, the absolute value of the difference between the indoor temperature TN and the air conditioner set temperature TS is ensured to be smaller than or equal to 0.5 ℃, namely, the operation frequency of the water pump 206, the first compressor 201 and the second compressor 203 is changed, the fan frequency in the fan coil 208 is changed, the opening degree of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 is changed, and the like through the coordination of the air conditioner data processing center 401, the indoor data acquisition control center 402 and the outdoor data acquisition control center 403, so that the whole air conditioning system equipment is in a high-efficiency operation state, and the waste of heating capacity of the air conditioner is reduced.

In the step S19, the air conditioning blowing mode is as follows: the outdoor unit of the air conditioner is not operated, and only the fan in the fan coil 208 of the indoor unit is operated under rated power, so that the indoor human body sensory temperature is reduced, and the dryness heat is reduced.

In the above step S21, the weak cooling mode max operation state is: and on the basis of the weak refrigeration mode, the running state of the whole air conditioning system is in a state of maximum refrigeration capacity. The operating frequency of the water pump 206 is 50Hz, the fans in the fan coil 208 are operated at the rated frequency, the opening degrees of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 are all maximum values allowed, and the second compressor 203 is operated at the rated frequency;

In the step S22, based on the analysis and processing of the indoor temperature TN data in the period of time corresponding to the continuous operation of the step S21 in the period of time corresponding to 0 to 30 minutes, the air conditioning data processing center 401 obtains the limit convergence value of the corresponding indoor temperature TN when the step S21 is assumed to be 45 minutes, and the limit convergence value is recorded as:

in the above step S23, the weak cooling mode energy saving operation state is: on the basis of a weak refrigeration mode, the absolute value of the difference value between the indoor temperature TN and the air conditioner set temperature TS is ensured to be less than or equal to 0.5 ℃, namely, the operation frequency of the water pump 206 and the second compressor 203 is changed, the fan frequency in the fan coil 208 is changed, and the opening operations of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 are changed through the coordination of the air conditioner data processing center 401, the indoor data acquisition control center 402 and the outdoor data acquisition control center 403, so that the whole air conditioning system equipment is in a high-efficiency operation state, and the waste of the heating capacity of the air conditioner is reduced;

In the above step S25, the strong cooling mode max is operated as follows: on the basis of the forced cooling mode, the running state of the whole air conditioning system is in a state with the maximum refrigerating capacity. The operating frequency of the water pump 206 is 50Hz, the fans in the fan coil 208 are operated under the rated frequency, the opening degrees of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 are all maximum values allowed, and the first compressor 201 and the second compressor 203 are operated under the rated power;

In the above step S26, if the return to step S25 is always performed and the step S27 cannot be performed, the meaning is that: even if the air conditioning system is operated at the maximum cooling capacity, the indoor temperature cannot always reach the air conditioning temperature set by the user. At this time, step S26 can ensure that the air conditioning system is always operated at the maximum cooling capacity. The representation is: based on the state of continuously operating the step S25, in the corresponding time of 0-30 minutes, the air-conditioning data processing center 401 analyzes and processes the indoor temperature TN data in the time to obtain the limit convergence value of the corresponding indoor temperature TN when the step S25 is assumed to be 45 minutes;

In the step S27, the forced cooling mode energy-saving operation state is: on the basis of the forced cooling mode, the absolute value of the difference between the indoor temperature TN and the air conditioner set temperature TS is ensured to be smaller than or equal to 0.5 ℃, namely, the operation frequency of the water pump 206, the first compressor 201 and the second compressor 203 is changed, the fan frequency in the fan coil 208 is changed, the opening degree of the first expansion valve 211, the second expansion valve 214 and the third expansion valve 216 is changed, and the like through the coordination of the air conditioner data processing center 401, the indoor data acquisition control center 402 and the outdoor data acquisition control center 403, so that the whole air conditioning system equipment is in a high-efficiency operation state, and the waste of the heating capacity of the air conditioner is reduced.

In the step S30, the airless mode of the air conditioner is: the air conditioning outdoor units are all turned off, the indoor units are also all turned off, and the fans in the fan coil 208 are turned off. At this time, the indoor temperature TN is lower than the air conditioning temperature TS set by the user, but the temperature difference is within 5 ℃, and the indoor temperature TN is lower than the outdoor temperature TW, and since the outdoor temperature is higher than the indoor temperature, the outdoor heat will spontaneously transfer to the indoor, and the indoor human body will spontaneously dissipate heat, which will jointly cause the indoor temperature to rise.

Working principle:

Embodiment one: in the forced hot mode, the air conditioning system is started simultaneously with the first compressor 201 and the second compressor 203; the e and f ends of the three-way valve 219 are opened, and the g end is closed; the end a of the four-way reversing valve 204 is communicated with the end b, and the end d is communicated with the end c; the first flash tank 212 and the second flash tank 215 are operated simultaneously; the first control valve 210 and the second control valve 213 are opened; the blower 218 is turned on; the water pump 206 is turned on and the fans within the fan coil 208 are turned on; the first expansion valve 211, the second expansion valve 214, and the third expansion valve 216 are all opened.

In the forced heat mode, as shown in fig. 3, the working medium of the air conditioning system operates, the zeotropic refrigerant forms high-pressure superheated gas through the first compressor 201 and the second compressor 203, enters the liquid-separating heat exchanger 205 for condensation through the a end and the b end of the four-way reversing valve 204, the refrigerant rich in high-boiling components is condensed first and timely discharged to the second expansion valve 214, and the refrigerant rich in low-boiling components is condensed and discharged to the first expansion valve 211. The high-pressure saturated liquid rich in low-boiling components becomes a medium-pressure gas-liquid mixed state coolant through the throttling expansion effect of the first expansion valve 211, enters the first flash tank 212, and through the flash evaporation effect, the medium-pressure saturated gaseous coolant extremely rich in low-boiling components is led to the first control valve 210,2, and the medium-pressure saturated liquid state coolant rich in high-boiling components is returned to the second flash tank 215 through the second control valve 213. The high-pressure refrigerant rich in high boiling point components flowing out of the liquid-dividing heat exchanger 206 is changed into a medium-pressure gas-liquid mixed state refrigerant by the throttling expansion action of the second expansion valve 214, and is converged with the high boiling point components passing through the second control valve 213, flows into the second flash tank 215, passes through the flash evaporation action of the second flash tank 215, and the medium-pressure saturated gaseous refrigerant rich in low boiling point components is led to the first control valve 210, and the medium-pressure saturated liquid refrigerant extremely rich in high boiling point components flows into the third expansion valve 216. The medium pressure saturated gaseous coolant enriched in low boiling components from the first flash tank 212, the second flash tank 215 is collected, returned to the second compressor 203 through the first control valve 210, and subjected to enhanced vapor injection. The medium pressure saturated liquid refrigerant from the second flash tank 215, which is extremely rich in high boiling components, passes through the third expansion valve 216 to become a low pressure gas-liquid mixed state refrigerant, then passes through the outdoor heat exchanger 217 to become a low pressure saturated gas refrigerant, passes through the d and c ends of the four-way reversing valve 204, and finally passes through the e and f ends (g ends are closed) of the three-way valve 219 to flow into the first compressor 201. The water pump 206 is started, water in the chilled water pipe network circulates, and a fan in the fan coil 208 is started to provide heat for the indoor air-conditioning area 301;

Embodiment two: in the weak heating mode, the air conditioning system is turned off the first compressor 201 and the second compressor 203 is turned on; the e and g ends of the three-way valve 219 are opened, and the f end is closed; the end a of the four-way reversing valve 204 is communicated with the end b, and the end d is communicated with the end c; the first flash tank 212 and the second flash tank 215 are operated simultaneously; the first control valve 210 and the second control valve 213 are opened; the blower 218 is turned on; the water pump 206 is turned on and the fans within the fan coil 208 are turned on; the first expansion valve 211, the second expansion valve 214, and the third expansion valve 216 are all opened;

compared with the forced heating mode, the working medium running condition of the air conditioning system in the weak heating mode is different in that the first compressor 201 is closed, the three-way valves e and g are opened, the f is closed, and the coolant flowing through the outdoor heat exchanger 217 and the four-way reversing valve 204 flows in through the three-way valve e and flows out of the g. The shutoff valve 202 is for preventing the coolant from flowing backward into the second compressor 203;

embodiment III: in the strong defrosting mode of the air conditioning system, the first compressor 201 is turned off, and the second compressor 203 is turned on; the end a of the four-way reversing valve 204 is communicated with the end d, and the end b is communicated with the end c; the first control valve 210 and the second control valve 213 are opened; the blower 218 is turned on; the water pump 206 is off and the fan within the fan coil 208 is off; the first expansion valve 211 and the second expansion valve 214 are closed, and the third expansion valve 216 is opened; the first flash tank 212 and the second flash tank 215 are operated simultaneously;

In the strong defrosting mode, the working medium operation condition of the air conditioning system is shown in fig. 4. The non-azeotropic refrigerant forms high pressure superheated gas through the second compressor 203, forms high pressure saturated liquid coolant through the external heat exchanger 217 through the a and d ends of the four-way reversing valve 204, and flows through the third expansion valve 216 to become mist medium pressure gas-liquid mixed state coolant, and flows into the second flash tank 215. Medium pressure saturated gaseous refrigerant enriched in low boiling components is withdrawn from the upper outlet of the second flash tank 215 and flows to the first control valve 210. The medium-pressure liquid coolant rich in high boiling point components is discharged from the outlet at the other end of the second flash tank 215, and since the second expansion valve 214 is in a closed state, the liquid coolant flows only to the second control valve 213, and the second control valve 213 is in an open state, by adjusting the opening degree of the second control valve 213, a part of the liquid coolant flows to the first flash tank 212 to be flashed. The medium pressure saturated gaseous refrigerant rich in low boiling point components is discharged from the upper end outlet of the first flash tank 212 and flows to the first control valve 210, and the liquid refrigerant in the first flash tank 212 is stored in the tank due to the closed state of the first expansion valve 211. Medium pressure saturated gaseous refrigerant enriched in low boiling components from the first flash tank 212, the second flash tank 215, is returned to the second compressor 203 through the first control valve 210, forming a complete refrigerant cycle;

Embodiment four: in the weak defrosting mode of the air conditioning system, the first compressor 201 is turned off, and the second compressor 203 is turned on; the end a of the four-way reversing valve 204 is communicated with the end d, and the end b is communicated with the end c; the first control valve 210 is opened and the second control valve 213 is closed; the blower 218 is turned on; the water pump 206 is off and the fan within the fan coil 208 is off; the first expansion valve 211 and the second expansion valve 214 are closed, and the third expansion valve 216 is opened; the second flash tank 215 is operational and the first flash tank 212 is not operational;

The air conditioning system working medium operation in the weak defrost mode is different from that in the strong defrost mode in that the second control valve 213 is closed and the first flash tank 212 is not operated. The weak defrosting mode is only flash-evaporated once, while the strong defrosting mode is flash-evaporated twice;

Fifth embodiment: in the forced cooling mode, the air conditioning system is started simultaneously with the first compressor 201 and the second compressor 203; the e and f ends of the three-way valve 219 are opened, and the g end is closed; the end a of the four-way reversing valve 204 is communicated with the end d, and the end b is communicated with the end c; the first control valve 210 and the second control valve 213 are closed; the blower 218 is turned on; the water pump 206 is turned on and the fans within the fan coil 208 are turned on; the first expansion valve 211, the second expansion valve 214, and the third expansion valve 216 are all opened; the first flash tank 212 and the second flash tank 215 are not intentionally operated by the flash operation, and only the coolant is passed through the two tanks;

In the forced cooling mode, as shown in fig. 5, the working medium of the air conditioning system operates, the zeotropic refrigerant forms a high-pressure superheated gaseous refrigerant through the first compressor 201 and the second compressor 203, forms a high-pressure saturated liquid refrigerant through the outdoor heat exchanger 217 through the a end and the d end of the four-way reversing valve 204, flows through the third expansion valve 216 to form a mist medium-pressure gas-liquid mixed state refrigerant, and flows into the second flash tank 215. Because the second flash tank 215 has larger space and lower pressure, a small part of the coolant mainly comprising low boiling point components is evaporated into medium-pressure saturated gaseous coolant and is discharged from an outlet at the upper end of the second flash tank 215, because the first control valve 210 is closed, the medium-pressure saturated gaseous coolant only enters the first flash tank 212, and because the second control valve 213 is closed, the medium-pressure coolant in the first flash tank 212 flows through the first expansion valve 211 to become low-pressure coolant in a mist gas-liquid mixed state and then flows into the liquid-dividing heat exchanger 205. Most of the coolant in the second flash tank 215 will flow out of the other end outlet to the second expansion valve 214 in a liquid state, become a mist-like gas-liquid mixed state coolant, and then enter the liquid-splitting heat exchanger 205. The coolant from the first expansion valve 211 and the second expansion valve 214 absorbs heat and evaporates in the liquid-splitting heat exchanger 205 to become low-pressure gaseous coolant, and flows in from the b end and the c end of the four-way reversing valve 204, flows in from the e end and the f end of the three-way valve 219, and finally returns to the first compressor 201; chilled water flowing through the liquid heat exchanger 205 and the water pump 206 has a reduced temperature, and the temperature of the indoor air conditioning area 301 is reduced by the rotation of the fan in the fan coil 208;

Example six: in the weak cooling mode, the first compressor 201 is turned off and the second compressor 203 is started; the e and f ends of the three-way valve 219 are opened, and the g end is closed; the end a of the four-way reversing valve 204 is communicated with the end d, and the end b is communicated with the end c; the second control valve 213 is closed; the blower 218 is turned on; the water pump 206 is turned on and the fans within the fan coil 208 are turned on; the first expansion valve 211, the second expansion valve 214, and the third expansion valve 216 are all opened; the first flash tank 212 and the second flash tank 215 are not intentionally operated by the flash operation, and only the coolant is passed through the two tanks;

The difference between the working medium running condition of the air conditioning system in the weak refrigeration mode and the forced cooling mode is that the first compressor 201 is turned off and the second compressor 203 is started; the three-way valves e and g are opened, and the f is closed; the coolant flows in through the end e of the three-way valve and flows out through the end g. The shutoff valve 202 is for preventing the coolant from flowing backward into the second compressor 203;

In the heating and cooling modes, according to the actual cold and hot load demands of the air conditioning system, the operating range of the working condition of the air conditioning system can be widened by adjusting the opening degrees of the first expansion valve 211 and the second expansion valve 214 and adjusting the working frequency of the compressor, so that the efficient energy-saving operation under different loads is realized;

In the defrosting mode, according to the actual defrosting requirement of the air conditioning system, the operating range of the working condition of the air conditioning system can be widened by adjusting the opening degrees of the first control valve 210 and the second control valve 213 and adjusting the working frequency of the compressor, so that the efficient energy-saving operation under different loads is realized.

Finally, it should be noted that: the foregoing description is only illustrative of the preferred embodiments of the present invention, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements or changes may be made without departing from the spirit and principles of the present invention.

Claims

1. A heat pump air conditioning system, characterized by: the system comprises a first compressor (201), a stop valve (202), a second compressor (203), a four-way reversing valve (204), a liquid separation heat exchanger (205), a water pump (206), a water supply temperature sensor (207), a fan coil (208), a backwater temperature sensor (209), a first control valve (210), a first expansion valve (211), a first flash tank (212), a second control valve (213), a second expansion valve (214), a second flash tank (215), a third expansion valve (216), an outdoor heat exchanger (217), a fan (218), a three-way valve (219), an indoor air conditioning area (301), an air conditioning data processing center (401), an indoor data acquisition control center (402) and an outdoor data acquisition control center (403);

The first compressor (201) is connected with the second compressor (203) through a stop valve (202), and the second compressor (203) is connected with the liquid-separating heat exchanger (205) through a four-way reversing valve (204); the light component outlet of the liquid separation heat exchanger (205) is connected with the first expansion valve (211), and the heavy component outlet is connected with the second expansion valve (214); the first expansion valve (211) is connected with the first flash tank (212), a light component outlet of the first flash tank (212) is connected with the first control valve (210), and a heavy component outlet of the first flash tank (212) is connected with the second control valve (213); the second expansion valve (214) and the second control valve (213) are connected with the second flash tank (215); the light component outlet of the second flash tank (215) is connected with the first control valve (210), and the heavy component outlet is connected with the third expansion valve (216); the first control valve (210) is connected with the second compressor (203); the outdoor heat exchanger (217) is matched with the fan (218) and is used for acquiring heat or cold in the air; the third expansion valve (216) is connected with the four-way reversing valve (204) through the outdoor heat exchanger (217), the four-way reversing valve (204) is connected with the e end of the three-way valve (219), the f end of the three-way valve (219) is connected with the first compressor (210), and the g end of the three-way valve (219) is directly connected with the second compressor (203).

2. A heat pump air conditioning system according to claim 1, comprising: the air-conditioning data processing center (401) comprises a data storage module (4011), a data analysis processing module (4012), a rule base module (4013) and a command sending module (4014).

3. A heat pump air conditioning system according to claim 1, comprising: the indoor data acquisition control center (402) comprises an indoor information uploading module (402), an indoor command receiving module (4022), an indoor temperature and humidity monitoring module (4023), an indoor unit operation information acquisition module (4024), a user command receiving module (4025) and an indoor unit operation state control module (4026).

4. A heat pump air conditioning system according to claim 1, characterized in that: the outdoor data acquisition control center (403) comprises an outdoor information uploading module (4031), an outdoor unit command receiving module (4032), an outdoor temperature and humidity monitoring module (4033), an outdoor heat exchanger frosting monitoring module (4034), an outdoor unit operation information acquisition module (4035) and an outdoor unit operation state control module (4036).

5. A heat pump air conditioning system according to claim 1, characterized in that: the first compressor (201) and the second compressor (203) are variable frequency compressors; the first expansion valve (211), the second expansion valve (214) and the third expansion valve (216) are electronic throttling expansion valves, and the opening degree can be adjusted; the first control valve (210), the second control valve (213) and the three-way valve (219) are all controlled by electromagnetism; the water pump 206 is a variable frequency regulating pump, and the motor is preferably a permanent magnet synchronous motor.

6. A method of operating a heat pump air conditioning system according to any of claims 1-5, comprising the steps of:

Step S1: judging whether an air conditioner user instruction receiving module (4025) receives a user starting instruction, if the air conditioner system receives the starting instruction, entering a step S2, otherwise, returning to the step S0;

Step S2: the indoor temperature and humidity monitoring module (4023) of the air conditioner, the outdoor temperature and humidity monitoring module (4033) of the air conditioner and the frosting monitoring module (4034) of the outdoor heat exchanger of the air conditioner are used for data acquisition and are uploaded to the air conditioner data processing center (401) through the indoor information uploading module (4021) and the outdoor information uploading module (4031) respectively; at this time, the air conditioner is in a standby state. Then, the process proceeds to step S3;

Step S3: judging whether the air conditioner user instruction receiving module 4025 receives a heating or cooling instruction of a user; if the air conditioning system receives a heating or refrigerating instruction of a user, the step S3 is entered, otherwise, the step S3 is returned to;

Step S4: the air conditioner data processing center (401) retrieves frosting coverage rate data of the surface of the outdoor heat exchanger (217) at the latest moment, judges whether the frosting coverage rate exceeds a limit value, if so, enters a step S5, otherwise, enters a step S8;

Step S8: judging whether the heating or cooling instruction received by the user instruction receiving module 4025 is specifically a heating instruction; if yes, entering a step S9, otherwise entering a step S20;