CN114992907A - Control method of heat pump system, and readable storage medium - Google Patents

Control method of heat pump system, and readable storage medium Download PDF

Info

Publication number
CN114992907A
CN114992907A CN202110229411.8A CN202110229411A CN114992907A CN 114992907 A CN114992907 A CN 114992907A CN 202110229411 A CN202110229411 A CN 202110229411A CN 114992907 A CN114992907 A CN 114992907A
Authority
CN
China
Prior art keywords
refrigerant
heat exchange
exchange channel
heat
pump system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202110229411.8A
Other languages
Chinese (zh)
Other versions
CN114992907B (en
Inventor
刘加劲
陈柯壁
丁云霄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GD Midea Heating and Ventilating Equipment Co Ltd
Hefei Midea Heating and Ventilating Equipment Co Ltd
Original Assignee
GD Midea Heating and Ventilating Equipment Co Ltd
Hefei Midea Heating and Ventilating Equipment Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GD Midea Heating and Ventilating Equipment Co Ltd, Hefei Midea Heating and Ventilating Equipment Co Ltd filed Critical GD Midea Heating and Ventilating Equipment Co Ltd
Priority to CN202110229411.8A priority Critical patent/CN114992907B/en
Publication of CN114992907A publication Critical patent/CN114992907A/en
Application granted granted Critical
Publication of CN114992907B publication Critical patent/CN114992907B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B30/00—Heat pumps
    • F25B30/02—Heat pumps of the compression type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2513—Expansion valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

The invention provides a control method of a heat pump system, the heat pump system and a readable storage medium. The control method of the heat pump system comprises the following steps: acquiring the supercooling degree of a first heat exchanger, the temperature difference of a refrigerant at an inlet and an outlet of a first heat exchange channel and the exhaust superheat degree of a compressor; and adjusting the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree, and adjusting the flow of the refrigerant in the first heat exchange channel according to the temperature difference of the refrigerant and the exhaust superheat degree so as to enable the refrigerant flowing into the injection port of the compressor to be in a gas-liquid two-phase state. The refrigerant at the injection port is controlled to be in a gas-liquid two-phase state, so that the heat recovery quantity of the heat pump system is increased, the capacity and the energy efficiency of the heat pump system at low temperature are obviously improved, the controllability of the exhaust temperature of the compressor is improved under the working condition of higher pressure ratio, the exhaust temperature can be ensured to be within the reasonable range requirement, and the system energy efficiency is enabled to be the highest.

Description

Control method of heat pump system, and readable storage medium
Technical Field
The invention belongs to the technical field of heat pump systems, and particularly relates to a control method of a heat pump system, the heat pump system and a readable storage medium.
Background
In the prior art, in order to improve the heating capacity of the heat pump at a low temperature, an enhanced vapor injection method is usually adopted, and air is supplied from a medium-pressure cavity of a compressor, so that the total refrigerant circulation quantity of the system is increased, and the total heating capacity of the system is improved. In the related art, under the working condition that the pressure ratio of a heat pump system is high, the exhaust temperature is too high, the controllability is poor, and the energy efficiency of the whole machine capacity is generally reduced.
Disclosure of Invention
The present invention has been made to solve one of the technical problems occurring in the prior art or the related art.
To this end, a first aspect of the invention proposes a control method of a heat pump system.
A second aspect of the present invention proposes a heat pump system.
A third aspect of the invention proposes a readable storage medium.
In view of the above, according to a first aspect of the present invention, a control method of a heat pump system is provided, the heat pump system including a compressor, a first heat exchanger, a second heat exchanger, and an economizer, the economizer including a first heat exchange passage and a second heat exchange passage, an inlet of the first heat exchange passage being connected to an outlet of the second heat exchange passage, an outlet of the first heat exchange passage being connected to an injection port of the compressor, and an outlet of the second heat exchange passage being connected to the second heat exchanger, the control method including: acquiring the supercooling degree of a first heat exchanger, the temperature difference of a refrigerant at an inlet and an outlet of a first heat exchange channel and the exhaust superheat degree of a compressor; and adjusting the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree, and adjusting the flow of the refrigerant in the first heat exchange channel according to the temperature difference of the refrigerant and the exhaust superheat degree so as to enable the refrigerant flowing into the injection port of the compressor to be in a gas-liquid two-phase state.
The invention provides a control method of a heat pump system, which is used for controlling the operation of the heat pump system. Wherein, the heat pump system includes compressor, first heat exchanger, second heat exchanger and economic ware. The compressor, the first heat exchanger and the second heat exchanger form a refrigerant loop, and the refrigerant absorbs heat, releases heat and is compressed in the refrigerant loop, so that the heat pump system can exchange heat with the outside. The economizer comprises a first heat exchange channel and a second heat exchange channel, an inlet and an outlet of the first heat exchange channel are respectively connected with an outlet of the second heat exchange channel and a jet orifice of the compressor, the first heat exchange channel is configured as an auxiliary path of the economizer, a refrigerant flows into the first heat exchange channel and then exchanges heat with the refrigerant in the second heat exchange channel, and the refrigerant after heat exchange flows out of the first heat exchange channel and then enters the jet orifice of the compressor, so that the compressor is sprayed to increase enthalpy. The inlet and the outlet of the second heat exchange channel are respectively connected with the first heat exchanger and the second heat exchanger, the second heat exchange channel is configured to be a main path of the economizer, the first heat exchanger is configured to be a condenser in the heat pump system, the second heat exchanger is configured to be an evaporator in the heat pump system, in the process that the refrigerant flowing out of the first heat exchanger passes through the first heat exchange channel of the economizer, the refrigerant exchanges heat with the second heat exchange channel, and the refrigerant after heat exchange enters the air return port of the compressor to be compressed again after flowing through the heat exchangers. The refrigerant in the first heat exchange channel exchanges heat through the second heat exchange channel, so that the enthalpy value of the refrigerant in the first heat exchange channel can be increased, and the enthalpy increasing effect on the injection of the compressor is improved.
The control method of the heat pump system provided by the invention controls the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger and the flow of the refrigerant in the first heat exchange channel, so that the refrigerant entering the injection port of the compressor is in a gas-liquid two-phase state. Through controlling the refrigerant at the injection port into a gas-liquid two-phase state, compared with a scheme of increasing vapor injection through a gaseous refrigerant in the related art, the controllability of the exhaust temperature of the compressor under the working condition of a high pressure ratio is improved, the exhaust temperature can be ensured to be within the requirement of a reasonable range, and the system energy efficiency is enabled to reach the highest. The exhaust temperature of the heat pump system at a high pressure ratio can be controlled, so that the heating capacity of the heat pump system is improved, and the running range of the system is widened. Because the refrigerant is subcooled by the second heat exchange channel of the economizer and then partially reenters the first heat exchange channel to evaporate and absorb heat, and the refrigerants in the first heat exchange channel and the second heat exchange channel of the economizer are both liquid refrigerants, the heat exchange quantity of the economizer is increased, the heat recovery quantity of the system is increased, and the capacity and the energy efficiency of the heat pump system at low temperature are obviously improved.
It can be understood that in the heat pump system for increasing vapor injection by gaseous refrigerant in the related art, in the case that the pressure ratio of the compressor is higher than 9, the exhaust temperature may be too high, resulting in poor controllability. The invention improves the controllability of the exhaust temperature by inputting the gas-liquid two-phase refrigerant into the jet orifice.
And controlling the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree of the first heat exchanger. In the operation process of the heat pump system, the supercooling degree of the first heat exchanger is continuously acquired, the flow of the refrigerant between the second heat exchangers is controlled according to the acquired supercooling degree, the refrigerants in the first heat exchange channel and the second heat exchange channel in the economizer can be guaranteed to be liquid refrigerants, the refrigerant of the injection path is guaranteed to reach the optimal state, and the heat recovery capacity of the heat pump system is improved. The flow of the refrigerant in the first heat exchange channel is controlled according to the temperature difference of the refrigerant at the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree of the compressor, so that the state of the refrigerant in the injection path is further controlled, and the heat pump system can operate at high energy efficiency.
In addition, according to the control method of the heat pump system in the above technical solution provided by the present invention, the following additional technical features may be further provided:
in a possible design, the step of obtaining the supercooling degree of the first heat exchanger specifically includes: acquiring an exhaust pressure value of a compressor, and acquiring a first temperature value at a refrigerant outlet of a first heat exchanger; and searching a corresponding saturation temperature value according to the exhaust pressure value, and determining the supercooling degree according to the saturation temperature value and the first temperature value.
In the design, the supercooling degree of the first heat exchanger is obtained in a calculation mode, and the specific formula is as follows:
T sc ＝T C－ T 1 。
wherein, T sc Is super-cooling degree, T C Is the saturation temperature value, T 1 Is a first temperature value.
The method comprises the steps of obtaining an exhaust pressure value of a compressor and a first temperature value at a refrigerant outlet of a first heat exchanger, finding a saturation temperature value corresponding to the exhaust pressure of the compressor in a table look-up mode, and calculating the supercooling degree of the first heat exchanger according to the saturation temperature value and the first temperature value. The supercooling degree of the first heat exchanger calculated by the method is accurate, and the heat recovery amount of the economizer and the injected refrigerant in a gas-liquid two-phase state can be ensured by controlling the refrigerant flow from the second heat exchange channel to the second heat exchanger according to the supercooling degree calculated by the formula.
In a possible design, the heat pump system further includes a throttling component, which is arranged on a pipeline between the outlet of the second heat exchange channel and the second heat exchanger, and the step of adjusting the flow rate of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree specifically includes: controlling the opening degree of the throttling component to be increased based on the supercooling degree being more than or equal to a first set supercooling degree; and controlling the opening degree of the throttling component to be reduced based on the supercooling degree less than or equal to a second set supercooling degree, wherein the first set supercooling degree is greater than the second set supercooling degree.
In the design, the heat pump system further comprises a throttling component, and the throttling component is arranged on a refrigerant pipeline between the second heat exchange channel and the second heat exchanger. The refrigerant flow between the outlet of the second heat exchange channel and the second heat exchanger can be directly adjusted by controlling the opening of the throttling component. The throttling component is adjusted according to the supercooling degree of the first heat exchanger in the following way:
and continuously acquiring the supercooling degree of the first heat exchanger, and when the supercooling degree is detected to be more than or equal to a first set supercooling degree, judging that the supercooling degree is overhigh at the moment, and controlling the throttle part to increase the opening degree. When the supercooling degree is detected to be less than or equal to a second set supercooling degree, the supercooling degree is judged to be too low at the moment, the expansion valve is controlled to reduce the opening degree, and the first set supercooling degree is greater than the second set supercooling degree. And when the obtained supercooling degree is within the numerical value range, judging that the opening degree of the throttling component does not need to be adjusted. The opening degree of the throttling component is adjusted through the supercooling degree of the outlet of the first heat exchanger, so that the heat recovery quantity of the economizer can be ensured, and the refrigerant at the injection port of the compressor is a gas-liquid two-phase refrigerant.
In one possible design, the heat pump system further includes: the expansion valve is arranged on a pipeline between an inlet of the first heat exchange channel and an outlet of the second heat exchange channel, and the step of adjusting the flow of the refrigerant in the first heat exchange channel according to the refrigerant temperature difference and the exhaust superheat degree specifically comprises the following steps: acquiring a target exhaust superheat interval and a set temperature difference; and adjusting the opening degree of the expansion valve to ensure that the temperature difference of the refrigerant is less than the set temperature difference and the exhaust superheat degree is within a target exhaust superheat degree interval.
In this design, the heat pump system further includes an expansion valve disposed on the refrigerant line between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel. The on-off state of the expansion valve is controlled, whether the refrigerant in the second heat exchange channel is guided into the first heat exchange channel can be controlled, and the opening degree of the expansion valve can be adjusted, so that the flow of the refrigerant entering the first heat exchange channel can be adjusted.
The step of adjusting the refrigerant flow in the first heat exchange channel according to the refrigerant temperature difference between the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree comprises the following steps: and acquiring a target superheat degree interval and a set temperature difference, and adjusting the opening degree of the expansion valve according to the numerical relationship between the refrigerant temperature difference and the set temperature difference and the numerical relationship between the exhaust superheat degree and the target superheat degree interval. The refrigerant temperature difference can be smaller than the set temperature difference by adjusting the opening degree of the expansion valve, and the exhaust superheat degree is in a target exhaust superheat degree interval.
It can be understood that, if the temperature difference is smaller than the set temperature difference, it can be determined that the state of the refrigerant at this time is a gas-liquid two-phase refrigerant. On the other hand, in order to reduce the temperature difference, the opening degree of the expansion valve needs to be increased as much as possible, and in order to avoid an excessively large opening degree of the expansion valve and an excessively low degree of superheat of the exhaust gas from the compressor, the opening degree of the expansion valve is adjusted again in accordance with the degree of superheat of the exhaust gas. The refrigerant at the injection port is in a gas-liquid two-phase state on the premise of ensuring the stable operation of the compressor. The overall capacity and energy efficiency of the heat pump system are improved, and the running stability of the heat pump system is also ensured.
In a possible design, the step of adjusting the opening degree of the expansion valve specifically includes: controlling the expansion valve to increase the opening degree based on the refrigerant temperature difference being greater than or equal to the set temperature difference; and determining that the exhaust superheat degree is smaller than the minimum value of the target exhaust superheat degree interval, and controlling the expansion valve to reduce the opening degree.
In the design, in the process of adjusting the opening degree of the expansion valve, the opening degree of the expansion valve needs to be adjusted according to the numerical relationship between the refrigerant temperature difference and the set temperature difference, and when the refrigerant temperature difference is lower than the set temperature difference, the opening degree of the expansion valve is adjusted according to the exhaust superheat degree of the compressor. In order to enable the refrigerant temperature difference to be lower than the set temperature difference, the opening degree of the expansion valve needs to be opened as large as possible, if the opening degree of the expansion valve is too large, the exhaust superheat degree of the compressor is too low, and therefore in the initial stage of operation of the heat pump system, the set temperature difference is adjusted to be lower than the set temperature difference through adjusting the expansion valve, and then the expansion valve is adjusted according to the exhaust superheat degree.
Specifically, after the heat pump system starts to operate and is in an operation state of increasing enthalpy of injection to the compressor, the refrigerant temperature difference of the first heat exchange channel is continuously collected, and after the refrigerant temperature difference is detected to be larger than a set temperature difference, the expansion opening degree is increased until the refrigerant temperature difference is smaller than the set temperature difference. Based on the working condition that the refrigerant temperature difference is smaller than the set temperature difference, the exhaust superheat degree of the compressor is obtained at the moment, the exhaust superheat degree is compared with a target exhaust superheat degree interval in a numerical value mode, when the exhaust superheat degree is smaller than the minimum value of the target exhaust superheat degree interval, the expansion valve is controlled to reduce the opening degree until the exhaust superheat degree is in the target exhaust superheat degree interval, the opening degree of the expansion valve is kept, and the refrigerant temperature difference and the exhaust superheat degree are continuously detected. In the subsequent operation, if the temperature difference of the refrigerant rises back to exceed the set temperature difference, the expansion valve is opened continuously, so that the state of the refrigerant flowing to the injection port of the compressor is a gas-liquid two-phase state. If the exhaust superheat degree of the compressor is not in the target exhaust superheat degree interval, the opening degree of the expansion valve is adjusted to enable the exhaust superheat degree to enter the target exhaust superheat degree interval, the stability of the operation of the compressor is guaranteed, and therefore the stability of the operation of the heat pump system is guaranteed.
In some embodiments, the set temperature difference is set to 2 ℃.
In one possible design, the step of obtaining the target exhaust superheat interval specifically includes: acquiring a return air pressure value of the compressor and an exhaust pressure value of the compressor; calculating according to the return air pressure value and the exhaust air pressure value to obtain a target exhaust superheat degree; and determining a target exhaust superheat interval according to the target exhaust superheat.
In the design, the target exhaust superheat degree is obtained by acquiring the target exhaust superheat degree interval and calculating according to a required line, and then the exhaust superheat degree interval is determined according to the target exhaust superheat degree. The calculation of the target exhaust superheat degree needs to be performed according to a pressure ratio, wherein the pressure ratio is a ratio of the highest pressure to the lowest pressure in the heat pump system, the highest pressure in the heat pump system is the exhaust pressure of the compressor, and the lowest pressure in the heat pump system is the return pressure of the compressor, and the specific calculation formula is as follows:
DSH＝α×(P1/P2)；
wherein D is SH Is the target degree of superheat of the exhaust gas, P 1 Is the discharge pressure value, P, of the compressor 2 The value of the return air pressure of the compressor is obtained.
After the target exhaust superheat degree is obtained through calculation, the minimum value and the maximum value in the target exhaust superheat degree interval are obtained through adding and subtracting set values to the target exhaust superheat degree, and therefore the target exhaust superheat degree interval is determined. The value range of the set value is 3 to 5.
According to a second aspect of the present invention, a heat pump system is provided, the heat pump system includes a compressor, a first heat exchanger, and a second heat exchanger, the compressor, the first heat exchanger, and the second heat exchanger are configured to form a refrigerant circuit, and the heat pump system further includes: the economizer comprises a first heat exchange channel and a second heat exchange channel, wherein the inlet of the first heat exchange channel is connected with the outlet of the second heat exchange channel, the outlet of the first heat exchange channel is connected with the injection port of the compressor, and the outlet of the second heat exchange channel is connected with the second heat exchanger; a memory having a program or instructions stored thereon; a processor executing a program or instructions to implement the steps of the method of controlling a heat pump system as described in any one of the possible designs above.
The heat pump system provided by the invention comprises a compressor, a first heat exchanger, a second heat exchanger and an economizer. The compressor, the first heat exchanger and the second heat exchanger form a refrigerant loop, and the refrigerant absorbs heat, releases heat and is compressed in the refrigerant loop, so that the heat pump system can exchange heat with the outside. The economizer comprises a first heat exchange channel and a second heat exchange channel, an inlet and an outlet of the first heat exchange channel are respectively connected with an outlet of the second heat exchange channel and a jet orifice of the compressor, the first heat exchange channel is configured as an auxiliary path of the economizer, a refrigerant flows into the first heat exchange channel and then exchanges heat with the refrigerant in the second heat exchange channel, and the refrigerant after heat exchange flows out of the first heat exchange channel and then enters the jet orifice of the compressor, so that the compressor is sprayed to increase enthalpy. The inlet and the outlet of the second heat exchange channel are respectively connected with the first heat exchanger and the second heat exchanger, the second heat exchange channel is configured to be a main path of the economizer, the first heat exchanger is configured to be a condenser in the heat pump system, the second heat exchanger is configured to be an evaporator in the heat pump system, in the process that the refrigerant flowing out of the first heat exchanger passes through the first heat exchange channel of the economizer, the refrigerant exchanges heat with the second heat exchange channel, and the refrigerant after heat exchange enters the air return port of the compressor to be compressed again after flowing through the heat exchangers. The refrigerant in the first heat exchange channel is subjected to heat exchange through the second heat exchange channel, so that the enthalpy value of the refrigerant in the first heat exchange channel is increased, and the enthalpy increasing effect on the injection of the compressor is improved.
The heat pump system provided by the invention further comprises a memory and a processor, wherein the processor executes a program or an instruction stored in the memory and can control the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger and the flow of the refrigerant in the first heat exchange channel, so that the refrigerant flowing into the injection port of the compressor is in a gas-liquid two-phase state.
Specifically, the control method of the heat pump system provided by the invention controls the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger and the flow of the refrigerant in the first heat exchange channel, so that the refrigerant entering the injection port of the compressor is in a gas-liquid two-phase state. Through controlling the refrigerant at the injection port into a gas-liquid two-phase state, compared with a scheme of increasing vapor injection through a gaseous refrigerant in the related art, the controllability of the exhaust temperature of the compressor under the working condition of a high pressure ratio is improved, the exhaust temperature can be ensured to be within the requirement of a reasonable range, and the system energy efficiency is enabled to reach the highest. The exhaust temperature of the heat pump system at a high pressure ratio can be controlled, so that the heating capacity of the heat pump system is improved, and the running range of the system is widened. Because the refrigerant is supercooled by the second heat exchange channel of the economizer and then partially reenters the first heat exchange channel to be evaporated and absorb heat, and the refrigerants in the first heat exchange channel and the second heat exchange channel of the economizer are liquid refrigerants, the heat exchange quantity of the economizer is increased, the heat recovery quantity of the system is increased, and the capacity and the energy efficiency of the heat pump system at low temperature are obviously improved.
It can be understood that in the heat pump system for increasing vapor injection by gaseous refrigerant in the related art, in the case that the pressure ratio of the compressor is higher than 9, the exhaust temperature may be too high, resulting in poor controllability. The invention improves the controllability of the exhaust temperature by inputting the gas-liquid two-phase refrigerant into the jet orifice.
And controlling the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree of the first heat exchanger. In the operation process of the heat pump system, the supercooling degree of the first heat exchanger is continuously acquired, the flow of the refrigerant between the second heat exchangers is controlled according to the acquired supercooling degree, and the refrigerant of the injection passage can be ensured to reach the optimal state. The flow of the refrigerant in the first heat exchange channel is controlled according to the temperature difference of the refrigerant at the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree of the compressor, so that the state of the refrigerant in the injection path is further controlled, and the heat pump system can operate at high energy efficiency.
In addition, according to the heat pump system in the above technical solution provided by the present invention, the following additional technical features may be further provided:
in one possible design, the heat pump system further includes: the throttling component is arranged on a pipeline between the outlet of the second heat exchange channel and the second heat exchanger; and the expansion valve is arranged on a pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel.
In the design, the heat pump system further comprises a throttling component, and the throttling component is arranged on a refrigerant pipeline between the second heat exchange channel and the second heat exchanger. The refrigerant flow between the outlet of the second heat exchange channel and the second heat exchanger can be directly adjusted by controlling the opening of the throttling part. The adjusting mode of the throttling component according to the supercooling degree of the first heat exchanger is as follows:
and continuously acquiring the supercooling degree of the first heat exchanger, and when the supercooling degree is detected to be more than or equal to a first set supercooling degree, judging that the supercooling degree is overhigh at the moment, and controlling the throttle part to increase the opening degree. When the supercooling degree is detected to be less than or equal to the second set supercooling degree, the supercooling degree is judged to be too low, the expansion valve is controlled to reduce the opening degree, and the first set supercooling degree is greater than the second set supercooling degree. And when the obtained supercooling degree is in the numerical value interval, judging that the opening degree of the throttling component is not required to be adjusted. The opening degree of the throttling component is adjusted through the supercooling degree of the outlet of the first heat exchanger, so that the heat recovery quantity of the economizer can be ensured, and the refrigerant at the injection port of the compressor is a gas-liquid two-phase refrigerant.
The heat pump system also comprises an expansion valve, and the expansion valve is arranged on a refrigerant pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel. The on-off state of the expansion valve is controlled, whether the refrigerant in the second heat exchange channel is guided into the first heat exchange channel can be controlled, and the opening degree of the expansion valve can be adjusted, so that the flow of the refrigerant entering the first heat exchange channel can be adjusted.
The step of adjusting the refrigerant flow in the first heat exchange channel according to the refrigerant temperature difference between the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree comprises the following steps: and acquiring a target superheat degree interval and a set temperature difference, and adjusting the opening degree of the expansion valve according to the numerical relationship between the refrigerant temperature difference and the set temperature difference and the numerical relationship between the exhaust superheat degree and the target superheat degree interval. The temperature difference of the refrigerant can be smaller than the set temperature difference by adjusting the opening degree of the expansion valve, and the exhaust superheat degree is in a target exhaust superheat degree interval.
It can be understood that, if the temperature difference is smaller than the set temperature difference, it can be determined that the state of the refrigerant at this time is a gas-liquid two-phase refrigerant. On the other hand, in order to reduce the temperature difference, the opening degree of the expansion valve needs to be increased as much as possible, and in order to avoid an excessively large opening degree of the expansion valve and an excessively low degree of superheat of the exhaust gas from the compressor, the opening degree of the expansion valve is adjusted again in accordance with the degree of superheat of the exhaust gas. The refrigerant at the injection port is in a gas-liquid two-phase state on the premise of ensuring the stable operation of the compressor. The overall capacity and energy efficiency of the heat pump system are improved, and the running stability of the heat pump system is also ensured.
In one possible design, the heat pump system further includes: the first temperature acquisition device is arranged on a pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel; and the second temperature acquisition device is arranged at the outlet of the first heat exchange channel.
In this design, the heat pump system further includes a first temperature acquisition device and a second temperature acquisition device. The first temperature acquisition device is arranged on a refrigerant pipeline between an inlet of the first heat exchange channel and an outlet of the second heat exchange channel, and the second temperature acquisition device is arranged on the refrigerant pipeline between the outlet of the first heat exchange channel and the jet orifice of the compressor. The first temperature acquisition device can acquire the temperature of the refrigerant before entering the first heat exchange channel, and the second temperature acquisition device can acquire the temperature value of the refrigerant flowing out of the first heat exchange channel, so that the temperature difference of the refrigerant flowing through the first heat exchange channel can be calculated.
It can be understood that the refrigerant is closer to a liquid state as the refrigerant temperature difference is smaller, and the refrigerant can be considered to be in a gas-liquid two-phase state when the refrigerant temperature difference is smaller than the set temperature difference. The opening degree of the expansion valve is adjusted and controlled according to the refrigerant temperature difference, and the refrigerant passing through the first heat exchange channel can be ensured to be in a gas-liquid two-phase state, so that the heat exchange of the refrigerant passing through the second heat exchange channel in the first heat exchange channel is improved, the temperature of the refrigerant entering a jet orifice of the compressor can be increased, and the enthalpy increasing effect of the compressor injection is improved.
In one possible design, the heat pump system further includes: the first pressure acquisition device is arranged on a refrigerant pipeline between an exhaust port of the compressor and the first heat exchanger.
In the design, the heat pump system further comprises a first pressure acquisition device, the first pressure acquisition device is arranged on a refrigerant pipeline between an exhaust port of the compressor and the first heat exchanger, and the exhaust pressure value of the compressor can be acquired.
Acquiring an exhaust pressure value of a compressor, and acquiring a first temperature value at a refrigerant outlet of a first heat exchanger; and searching a corresponding saturation temperature value according to the exhaust pressure value, and determining the supercooling degree according to the saturation temperature value and the first temperature value. The method comprises the steps of obtaining an exhaust pressure value of a compressor and a first temperature value at a refrigerant outlet of a first heat exchanger, finding a saturation temperature value corresponding to the exhaust pressure of the compressor in a table look-up mode, and calculating the supercooling degree of the first heat exchanger according to the saturation temperature value and the first temperature value. The supercooling degree of the first heat exchanger calculated by the method is accurate, and the heat recovery amount of the economizer and the injected refrigerant in a gas-liquid two-phase state can be ensured by controlling the refrigerant flow from the second heat exchange channel to the second heat exchanger according to the supercooling degree calculated by the formula.
In a possible design, an inlet of the second heat exchange channel is connected to a refrigerant outlet of the first heat exchanger, and the heat pump system further includes: the third temperature acquisition device is arranged at the outlet of the refrigerant of the first heat exchanger; and the fourth temperature acquisition device is arranged at the inlet of the refrigerant of the first heat exchanger.
In the design, the refrigerant flowing out of the first heat exchanger directly flows into the inlet of the second heat exchange channel, and the refrigerant entering the second heat exchange channel can exchange heat with the refrigerant in the first heat exchange channel. Because the refrigerants in the first heat exchange channel and the second heat exchange channel of the economizer are liquid refrigerants, the refrigerants of the injection path are ensured to reach the optimal state, the heat recovery of the heat pump system is increased, and the capacity and energy efficiency at low temperature are obviously improved.
The heat pump system further comprises a third temperature acquisition device and a fourth temperature acquisition device. The third temperature acquisition device is arranged at a refrigerant outlet of the first heat exchanger, the refrigerant directly enters an inlet of a second heat exchange channel of the economizer after flowing out of the first heat exchanger, and the third temperature acquisition device can acquire the temperature of the refrigerant flowing out of the first heat exchanger. The fourth temperature acquisition device is arranged at a refrigerant inlet of the first heat exchanger and can acquire the temperature of the refrigerant flowing into the first heat exchanger.
In some embodiments, the flow rate of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger is adjusted according to the supercooling degree. And controlling the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree of the first heat exchanger. In the operation process of the heat pump system, the supercooling degree of the first heat exchanger is continuously acquired, the flow of the refrigerant between the second heat exchangers is controlled according to the acquired supercooling degree, and the refrigerant of the injection passage can be ensured to reach the optimal state.
According to a third aspect of the present invention, a readable storage medium is proposed, on which a program or instructions are stored, which when executed by a processor implement the steps of the control method of a heat pump system as in any one of the possible designs described above. Therefore, the control method of the heat pump system in any possible design has all the beneficial technical effects, and will not be described in detail herein.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a schematic flow chart showing a control method of a heat pump system in a first embodiment of the present invention;
fig. 2 shows one of schematic flowcharts of a control method of the heat pump system in the second embodiment of the invention;
fig. 3 shows a second schematic flow chart of a method for controlling a heat pump system according to a second embodiment of the present invention;
fig. 4 shows one of schematic flowcharts of a control method of the heat pump system in the third embodiment of the invention;
fig. 5 shows a second schematic flow chart of a control method of the heat pump system in the third embodiment of the invention;
fig. 6 shows a third schematic flow chart of a control method of a heat pump system in a third embodiment of the invention;
fig. 7 is a schematic structural view showing a heat pump system according to a fourth embodiment of the present invention;
fig. 8 shows a schematic block diagram of a heat pump system in a fourth embodiment of the invention;
fig. 9 shows one of schematic flowcharts of a control method of the heat pump system in the fifth embodiment of the invention;
fig. 10 shows a second schematic flowchart of a method for controlling a heat pump system according to a fifth embodiment of the present invention.
Wherein, the correspondence between the reference numbers and the names of the components in fig. 7 is:
700 heat pump system, 702 compressor, 704 first heat exchanger, 706 second heat exchanger, 708 economizer, 7082 first heat exchange path, 7084 second heat exchange path, 710 throttle, 712 expansion valve, 714 first temperature acquisition device, 716 second temperature acquisition device, 718 first pressure acquisition device, 724 third temperature acquisition device, 726 fourth temperature acquisition device.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
A heat pump system, a control method of the heat pump system, and a readable storage medium according to some embodiments of the present invention are described below with reference to fig. 1 to 10.
The first embodiment is as follows:
as shown in fig. 1, in one embodiment of the present invention, a control method of a heat pump system is provided, the heat pump system includes a compressor, a first heat exchanger, a second heat exchanger, and an economizer, the economizer includes a first heat exchange channel and a second heat exchange channel, an inlet of the first heat exchange channel is connected to an outlet of the second heat exchange channel, an outlet of the first heat exchange channel is connected to an injection port of the compressor, and an outlet of the second heat exchange channel is connected to the second heat exchanger.
The control method of the heat pump system comprises the following steps:
102, acquiring the temperature difference of a refrigerant at an inlet and an outlet of a first heat exchange channel, the supercooling degree of a first heat exchanger and the exhaust superheat degree of a compressor;
104, adjusting the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree;
and 106, adjusting the refrigerant flow in the first heat exchange channel according to the refrigerant temperature difference and the exhaust superheat degree.
In this embodiment, the present invention provides a control method of a heat pump system for controlling the operation of the heat pump system. Wherein, the heat pump system includes compressor, first heat exchanger, second heat exchanger and economic ware. The compressor, the first heat exchanger and the second heat exchanger form a refrigerant loop, and the refrigerant absorbs heat, releases heat and is compressed in the refrigerant loop, so that the heat pump system can exchange heat with the outside. The economizer comprises a first heat exchange channel and a second heat exchange channel, an inlet and an outlet of the first heat exchange channel are respectively connected with an outlet of the second heat exchange channel and a jet orifice of the compressor, the first heat exchange channel is configured as an auxiliary path of the economizer, a refrigerant flows into the first heat exchange channel and then exchanges heat with the refrigerant in the second heat exchange channel, and the refrigerant after heat exchange flows out of the first heat exchange channel and then enters the jet orifice of the compressor, so that the compressor is subjected to injection enthalpy increasing. The inlet and the outlet of the second heat exchange channel are respectively connected with the first heat exchanger and the second heat exchanger, the second heat exchange channel is configured to be a main path of the economizer, the first heat exchanger is configured to be a condenser in the heat pump system, the second heat exchanger is configured to be an evaporator in the heat pump system, in the process that the refrigerant flowing out of the first heat exchanger passes through the first heat exchange channel of the economizer, the refrigerant exchanges heat with the second heat exchange channel, and the refrigerant after heat exchange enters the air return port of the compressor to be compressed again after flowing through the heat exchangers. The refrigerant in the first heat exchange channel is subjected to heat exchange through the second heat exchange channel, so that the enthalpy value in the first heat exchange channel can be increased, and the enthalpy increasing effect on the injection of the compressor is improved.
The control method for the heat pump system provided by the invention controls the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger and the flow of the refrigerant in the first heat exchange channel, so that the refrigerant entering the injection port of the compressor is in a gas-liquid two-phase state. Through controlling the refrigerant at the injection port into a gas-liquid two-phase state, compared with a scheme of increasing vapor injection through a gaseous refrigerant in the related art, the controllability of the exhaust temperature of the compressor under the working condition of a high pressure ratio is improved, the exhaust temperature can be ensured to be within the requirement of a reasonable range, and the system energy efficiency is enabled to reach the highest. The exhaust temperature of the heat pump system at a high pressure ratio can be controlled, so that the heating capacity of the heat pump system is improved, and the running range of the system is widened. Because the refrigerant is subcooled by the second heat exchange channel of the economizer and then partially reenters the first heat exchange channel to evaporate and absorb heat, and the refrigerants in the first heat exchange channel and the second heat exchange channel of the economizer are both liquid refrigerants, the heat exchange quantity of the economizer is increased, the heat recovery quantity of the system is increased, and the capacity and the energy efficiency of the heat pump system at low temperature are obviously improved.
It can be understood that in the heat pump system for increasing vapor injection by gaseous refrigerant in the related art, in the case that the pressure ratio of the compressor is higher than 9, the exhaust temperature may be too high, resulting in poor controllability. The invention improves the controllability of the exhaust temperature by inputting the gas-liquid two-phase refrigerant into the jet orifice.
And controlling the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree of the first heat exchanger. In the operation process of the heat pump system, the supercooling degree of the first heat exchanger is continuously acquired, the flow of the refrigerant between the second heat exchangers is controlled according to the acquired supercooling degree, the refrigerants in the first heat exchange channel and the second heat exchange channel in the economizer can be guaranteed to be liquid refrigerants, the refrigerant of the injection path is guaranteed to reach the optimal state, and the heat recovery capacity of the heat pump system is improved. The flow of the refrigerant in the first heat exchange channel is controlled according to the temperature difference between the refrigerant at the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree of the compressor, so that the state of the refrigerant in the injection path is further controlled, and the heat pump system can operate at high energy efficiency.
Example two:
as shown in fig. 2, on the basis of the control method of the heat pump system in the first embodiment, the step of obtaining the supercooling degree of the first heat exchanger specifically includes:
202, acquiring a discharge pressure value of a compressor and a first temperature value at a refrigerant outlet of a first heat exchanger;
step 204, searching a corresponding saturation temperature value according to the exhaust pressure value;
and step 206, determining the supercooling degree according to the saturation temperature value and the first temperature value.
In this embodiment, the supercooling degree of the first heat exchanger is obtained by calculation, and the specific formula is as follows:
T sc ＝T C－ T 1 。
wherein, T sc Is super-cooling degree, T C Is the saturation temperature value, T 1 Is a first temperature value.
The method comprises the steps of obtaining an exhaust pressure value of a compressor and a first temperature value at a refrigerant outlet of a first heat exchanger, finding a saturation temperature value corresponding to the exhaust pressure of the compressor in a table look-up mode, and calculating the supercooling degree of the first heat exchanger according to the saturation temperature value and the first temperature value. The supercooling degree of the first heat exchanger calculated by the method is accurate, and the heat recovery amount of the economizer and the injected refrigerant in a gas-liquid two-phase state can be ensured by controlling the refrigerant flow from the second heat exchange channel to the second heat exchanger according to the supercooling degree calculated by the formula.
In any of the above embodiments, the heat pump system further includes a throttling component disposed on a pipeline between an outlet of the second heat exchange channel and the second heat exchanger;
as shown in fig. 3, the step of adjusting the refrigerant flow between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree specifically includes:
step 302, determining that the supercooling degree is more than or equal to a first set supercooling degree, and controlling the opening degree of the throttling component to increase;
and 304, determining that the supercooling degree is less than or equal to a second set supercooling degree, and controlling the opening degree of the throttling component to be reduced.
Wherein the first set supercooling degree is greater than the second set supercooling degree.
In this embodiment, the heat pump system further includes a throttling component, and the throttling component is disposed on the refrigerant pipeline between the second heat exchange channel and the second heat exchanger. The refrigerant flow between the outlet of the second heat exchange channel and the second heat exchanger can be directly adjusted by controlling the opening of the throttling component. The adjusting mode of the throttling component according to the supercooling degree of the first heat exchanger is as follows:
and continuously acquiring the supercooling degree of the first heat exchanger, and when the supercooling degree is detected to be more than or equal to a first set supercooling degree, judging that the supercooling degree is overhigh at the moment, and controlling the throttle part to increase the opening degree. When the supercooling degree is detected to be less than or equal to the second set supercooling degree, the supercooling degree is judged to be too low, the expansion valve is controlled to reduce the opening degree, and the first set supercooling degree is greater than the second set supercooling degree. And when the obtained supercooling degree is in the numerical value interval, judging that the opening degree of the throttling component is not required to be adjusted. The opening degree of the throttling component is adjusted through the supercooling degree of the outlet of the first heat exchanger, so that the heat recovery quantity of the economizer can be ensured, and the refrigerant at the injection port of the compressor is a gas-liquid two-phase refrigerant.
Example three:
on the basis of the control method of the heat pump system in the first embodiment, the heat pump system further includes: and the expansion valve is arranged on a pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel.
As shown in fig. 4, the step of adjusting the refrigerant flow rate in the first heat exchange channel according to the refrigerant temperature difference and the exhaust superheat degree specifically includes:
step 402, acquiring a target exhaust superheat degree interval and a set temperature difference;
and step 404, adjusting the opening degree of the expansion valve so that the temperature difference of the refrigerant is smaller than the set temperature difference, and the exhaust superheat degree is within the target exhaust superheat degree interval.
In this embodiment, the heat pump system further includes an expansion valve disposed on the refrigerant pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel. The on-off state of the expansion valve is controlled, whether the refrigerant in the second heat exchange channel is guided into the first heat exchange channel can be controlled, and the opening degree of the expansion valve can be adjusted, so that the flow of the refrigerant entering the first heat exchange channel can be adjusted.
The step of adjusting the refrigerant flow in the first heat exchange channel according to the refrigerant temperature difference between the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree comprises the following steps: and acquiring a target superheat degree interval and a set temperature difference, and adjusting the opening degree of the expansion valve according to the numerical relationship between the refrigerant temperature difference and the set temperature difference and the numerical relationship between the exhaust superheat degree and the target superheat degree interval. The temperature difference of the refrigerant can be smaller than the set temperature difference by adjusting the opening degree of the expansion valve, and the exhaust superheat degree is in a target exhaust superheat degree interval.
It can be understood that, if the temperature difference is smaller than the set temperature difference, it can be determined that the state of the refrigerant at this time is a gas-liquid two-phase refrigerant. On the other hand, in order to reduce the temperature difference, the opening degree of the expansion valve needs to be increased as much as possible, and in order to avoid an excessively large opening degree of the expansion valve and an excessively low degree of superheat of the exhaust gas of the compressor, the opening degree of the expansion valve is adjusted again in accordance with the degree of superheat of the exhaust gas. The refrigerant at the injection port is in a gas-liquid two-phase state on the premise of ensuring the stable operation of the compressor. The overall capacity and energy efficiency of the heat pump system are improved, and the running stability of the heat pump system is also ensured.
As shown in fig. 5, in any of the above embodiments, the step of adjusting the opening degree of the expansion valve specifically includes:
step 502, determining that the temperature difference of the refrigerant is greater than or equal to a set temperature difference, and controlling an expansion valve to increase the opening degree;
and step 504, determining that the exhaust superheat degree is smaller than the minimum value of the target exhaust superheat degree interval, and controlling the expansion valve to reduce the opening degree.
In this embodiment, in the process of adjusting the opening degree of the expansion valve, the opening degree of the expansion valve needs to be adjusted according to the numerical relationship between the refrigerant temperature difference and the set temperature difference, and when the refrigerant temperature difference is lower than the set temperature difference, the opening degree of the expansion valve needs to be adjusted according to the exhaust superheat degree of the compressor. In order to enable the refrigerant temperature difference to be lower than the set temperature difference, the opening degree of the expansion valve needs to be opened as large as possible, if the opening degree of the expansion valve is too large, the exhaust superheat degree of the compressor is too low, and therefore in the initial stage of operation of the heat pump system, the set temperature difference is adjusted to be lower than the set temperature difference through adjusting the expansion valve, and then the expansion valve is adjusted according to the exhaust superheat degree.
Specifically, after the heat pump system starts to operate and is in an operation state of increasing the enthalpy of the compressor, the refrigerant temperature difference of the first heat exchange channel is continuously collected, and when the refrigerant temperature difference is detected to be larger than a set temperature difference, the expansion opening degree is increased until the refrigerant temperature difference is smaller than the set temperature difference. Based on the working condition that the refrigerant temperature difference is smaller than the set temperature difference, the exhaust superheat degree of the compressor is obtained at the moment, the exhaust superheat degree is compared with a target exhaust superheat degree interval in a numerical value mode, when the exhaust superheat degree is smaller than the minimum value of the target exhaust superheat degree interval, the expansion valve is controlled to reduce the opening degree until the exhaust superheat degree is in the target exhaust superheat degree interval, the opening degree of the expansion valve is kept, and the refrigerant temperature difference and the exhaust superheat degree are continuously detected. In the subsequent operation, if the temperature difference of the refrigerant rises back to exceed the set temperature difference, the expansion valve is opened continuously, so that the state of the refrigerant flowing to the injection port of the compressor is a gas-liquid two-phase state. If the exhaust superheat degree of the compressor is not in the target exhaust superheat degree interval, the opening degree of the expansion valve is adjusted to enable the exhaust superheat degree to enter the target exhaust superheat degree interval, the stability of the operation of the compressor is guaranteed, and therefore the stability of the operation of the heat pump system is guaranteed.
In some embodiments, the set temperature difference is set to 2 ℃.
As shown in fig. 6, in any of the above embodiments, the step of obtaining the target exhaust superheat degree interval specifically includes:
step 602, acquiring a return air pressure value of a compressor and a discharge air pressure value of the compressor;
step 604, calculating a target exhaust superheat degree according to the return air pressure value and the exhaust pressure value;
and 606, determining a target exhaust superheat degree interval according to the target exhaust superheat degree.
In the embodiment, the target exhaust superheat degree is obtained by acquiring a target exhaust superheat degree interval needing linear calculation, and then the exhaust superheat degree interval is determined according to the target exhaust superheat degree. The calculation of the target exhaust superheat degree needs to be performed according to a pressure ratio, wherein the pressure ratio is a ratio of the highest pressure to the lowest pressure in the heat pump system, the highest pressure in the heat pump system is the exhaust pressure of the compressor, and the lowest pressure in the heat pump system is the return pressure of the compressor, and the specific calculation formula is as follows:
D SH ＝α×(P 1 /P 2 )；
wherein D is SH Is the target degree of superheat of the exhaust gas, P 1 Is the discharge pressure value, P, of the compressor 2 The value of the return air pressure of the compressor is obtained.
After the target exhaust superheat degree is obtained through calculation, the minimum value and the maximum value in the target exhaust superheat degree interval are obtained through adding or subtracting set values to the target exhaust superheat degree, and therefore the target exhaust superheat degree interval is determined. The value range of the set value is 3 to 5.
It will be appreciated that the return air pressure value of the compressor is calculated from the ambient temperature, the outlet temperature of the second heat exchanger and the operating parameters of the compressor. A corresponding pressure sensor can be arranged at the return air port of the compressor, and the pressure value of the return air port of the compressor can be directly acquired through the pressure sensor.
Example four:
as shown in fig. 7 and 8, in another embodiment of the present invention, a heat pump system 700 is provided, the heat pump system 700 includes a compressor 702, a first heat exchanger 704 and a second heat exchanger 706 forming a refrigerant circuit, and the heat pump system 700 further includes: the economizer 708 comprises a first heat exchange channel 7082 and a second heat exchange channel 7084, wherein the inlet of the first heat exchange channel 7082 is connected with the outlet of the second heat exchange channel 7084, the outlet of the first heat exchange channel 7082 is connected with the injection port of the compressor 702, and the outlet of the second heat exchange channel 7084 is connected with the second heat exchanger 706; a memory 720, the memory 720 having programs or instructions stored thereon; processor 722, processor 722 executing a program or instructions implements the steps of a method of controlling a heat pump system as in any of the embodiments above.
As shown in fig. 7, the heat pump system 700 provided by the present invention includes a compressor 702, a first heat exchanger 704, a second heat exchanger 706, and an economizer 708. The compressor 702, the first heat exchanger 704 and the second heat exchanger 706 constitute a refrigerant loop, and the refrigerant performs heat absorption, heat release and compression processes in the refrigerant loop, so that the heat pump system 700 can exchange heat with the outside. The economizer 708 comprises a first heat exchange channel 7082 and a second heat exchange channel 7084, an inlet and an outlet of the first heat exchange channel 7082 are respectively connected with an outlet of the second heat exchange channel 7084 and an injection port of the compressor 702, the first heat exchange channel 7082 is configured as an auxiliary path of the economizer 708, a refrigerant flows into the first heat exchange channel 7082 and then exchanges heat with the refrigerant in the second heat exchange channel 7084, and the refrigerant after heat exchange flows out of the first heat exchange channel 7082 and then enters the injection port of the compressor 702, so that the compressor 702 is subjected to injection enthalpy increase. An inlet and an outlet of the second heat exchange channel 7084 are respectively connected to the first heat exchanger 704 and the second heat exchanger 706, the second heat exchange channel 7084 is configured as a main path of the economizer 708, the first heat exchanger 704 is configured as a condenser in the heat pump system 700, the second heat exchanger 706 is configured as an evaporator in the heat pump system 700, refrigerant flowing out of the first heat exchanger 704 exchanges heat with the second heat exchange channel 7084 in a process of passing through the first heat exchange channel 7082 of the economizer 708, and the refrigerant after heat exchange enters a return air port of the compressor 702 after passing through the heat exchangers and is compressed again. The refrigerant in the first heat exchange channel 7082 can be subjected to heat exchange through the second heat exchange channel 7084, so that the enthalpy value of the refrigerant in the first heat exchange channel 7082 can be increased, and the enthalpy increasing effect on the injection of the compressor 702 is improved.
As shown in fig. 8, the heat pump system 700 further includes a memory 720 and a processor 722, and the processor 722 executes a program or a command stored in the memory to control the flow rate of the refrigerant between the outlet of the second heat exchange passage 7084 and the second heat exchanger 706 and the flow rate of the refrigerant in the first heat exchange passage 7082, so that the refrigerant flowing into the injection port of the compressor 702 is in a gas-liquid two-phase state.
Specifically, the method for controlling the heat pump system according to the present invention controls the flow rate of the refrigerant between the outlet of the second heat exchange passage 7084 and the second heat exchanger 706, and controls the flow rate of the refrigerant in the first heat exchange passage 7082, so that the refrigerant entering the injection port of the compressor 702 is in a gas-liquid two-phase state. By controlling the refrigerant at the injection port to be in a gas-liquid two-phase state, compared with a scheme of increasing vapor injection through a gaseous refrigerant in the related art, the controllability of the exhaust temperature of the compressor 702 under the working condition of a high pressure ratio is improved, the exhaust temperature can be ensured to be within the requirement of a reasonable range, and the system energy efficiency is enabled to be the highest. The exhaust temperature of the heat pump system 700 at a high pressure ratio can be controlled, so that the heating capacity of the heat pump system 700 is improved, and meanwhile, the operation range of the system is widened. Because the part of the refrigerant after being subcooled by the second heat exchange channel 7084 of the economizer 708 reenters the first heat exchange channel 7082 to evaporate and absorb heat, and the refrigerants in the first heat exchange channel 7082 and the second heat exchange channel 7084 of the economizer 708 are both liquid refrigerants, the heat exchange amount of the economizer 708 is increased, the heat recovery amount of the system is increased, and the capacity and energy efficiency of the heat pump system 700 at low temperature are obviously improved.
It is understood that in the heat pump system 700 for increasing vapor injection by gaseous refrigerant in the related art, in the case that the pressure ratio of the compressor 702 is higher than 9, the exhaust temperature is too high, and the controllability is deteriorated. The invention improves the controllability of the exhaust temperature by inputting the gas-liquid two-phase refrigerant into the jet orifice.
And controlling the flow of the refrigerant between the outlet of the second heat exchange channel 7084 and the second heat exchanger 706 according to the supercooling degree of the first heat exchanger 704. In the operation process of the heat pump system 700, the supercooling degree of the first heat exchanger 704 is continuously acquired, the flow rate of the refrigerant between the second heat exchangers 706 is controlled according to the acquired supercooling degree, and it can be ensured that the refrigerants in the first heat exchange channel 7082 and the second heat exchange channel 7084 in the economizer are both liquid refrigerants, so that the refrigerant of the injection passage is ensured to reach the optimal state, and the heat recovery amount of the heat pump system 700 is increased. The flow rate of the refrigerant in the first heat exchange channel 7082 is controlled according to the temperature difference between the refrigerant at the inlet and the outlet of the first heat exchange channel 7082 and the exhaust superheat degree of the compressor 702, so that the state of the refrigerant in the injection passage is further controlled, and the heat pump system 700 operates with high energy efficiency.
In any of the above embodiments, the heat pump system 700 further comprises: the throttling part 710 is arranged on a pipeline between the outlet of the second heat exchange channel 7084 and the second heat exchanger 706; an expansion valve 712 is provided in a line between an inlet of the first heat exchange passage 7082 and an outlet of the second heat exchange passage 7084.
In this embodiment, the heat pump system 700 further includes a throttling component 710, and the throttling component 710 is disposed on the refrigerant pipeline between the second heat exchanging channel 7084 and the second heat exchanger 706. The refrigerant flow between the outlet of the second heat exchange passage 7084 and the second heat exchanger 706 can be directly adjusted by controlling the opening degree of the throttling component 710. The throttling component 710 is adjusted according to the supercooling degree of the first heat exchanger 704 in the following manner:
and continuously acquiring the supercooling degree of the first heat exchanger 704, and when detecting that the supercooling degree is greater than or equal to a first set supercooling degree, determining that the supercooling degree is too high at the moment, and controlling the throttle part 710 to increase the opening degree. When the supercooling degree is detected to be less than or equal to the second set supercooling degree, it is determined that the supercooling degree is too low, the expansion valve 712 is controlled to reduce the opening degree, and the first set supercooling degree is greater than the second set supercooling degree. And when the obtained supercooling degree is in the numerical value interval, judging that the opening degree of the throttling component 710 does not need to be adjusted. The opening degree of the throttle unit 710 is adjusted by the supercooling degree of the outlet of the first heat exchanger 704, so that the heat recovery amount of the economizer 708 can be ensured, and the refrigerant at the injection port of the compressor 702 is a gas-liquid two-phase refrigerant.
The heat pump system 700 further includes an expansion valve 712, and the expansion valve 712 is disposed on a refrigerant pipeline between an inlet of the first heat exchange passage 7082 and an outlet of the second heat exchange passage 7084. Whether the refrigerant in the second heat exchange channel 7084 is guided into the first heat exchange channel 7082 or not can be controlled by controlling the on-off state of the expansion valve 712, and the flow rate of the refrigerant entering the first heat exchange channel 7082 can be adjusted by adjusting the opening degree of the expansion valve 712.
The step of adjusting the refrigerant flow rate in the first heat exchange passage 7082 according to the refrigerant temperature difference between the inlet and the outlet of the first heat exchange passage 7082 and the exhaust superheat degree includes: the target superheat degree interval and the set temperature difference are obtained, and the opening degree of the expansion valve 712 is adjusted according to the numerical relationship between the refrigerant temperature difference and the set temperature difference and according to the numerical relationship between the exhaust superheat degree and the target superheat degree interval. The opening degree of the expansion valve 712 is adjusted to make the refrigerant temperature difference smaller than the set temperature difference, and the exhaust superheat degree is within the target exhaust superheat degree interval.
It can be understood that, if the temperature difference is smaller than the set temperature difference, it can be determined that the state of the refrigerant at this time is a gas-liquid two-phase refrigerant. On the other hand, in order to reduce the temperature difference, the opening degree of the expansion valve 712 needs to be increased as much as possible, and in order to avoid an excessively large opening degree of the expansion valve 712 and an excessively low degree of superheat of the exhaust gas of the compressor 702, the opening degree of the expansion valve 712 is adjusted again in accordance with the degree of superheat of the exhaust gas. The refrigerant at the injection port is in a gas-liquid two-phase state on the premise of ensuring the stable operation of the compressor 702. Not only improves the overall energy efficiency of the heat pump system 700, but also ensures the stability of the operation of the heat pump system 700.
In any of the above embodiments, the heat pump system 700 further comprises: a first temperature acquiring device 714 arranged on a pipeline between the inlet of the first heat exchange channel 7082 and the outlet of the second heat exchange channel 7084; and the second temperature acquisition device 716 is arranged at the outlet of the first heat exchange channel 7082.
In this embodiment, the heat pump system 700 further includes a first temperature capture device 714 and a second temperature capture device 716. The first temperature obtaining device 714 is arranged on a refrigerant pipeline between the inlet of the first heat exchange channel 7082 and the outlet of the second heat exchange channel 7084, and the second temperature obtaining device 716 is arranged on a refrigerant pipeline between the outlet of the first heat exchange channel 7082 and the injection port of the compressor 702. The first temperature obtaining device 714 can obtain the temperature of the refrigerant before entering the first heat exchange channel 7082, and the second temperature obtaining device 716 can obtain the temperature value of the refrigerant flowing out of the first heat exchange channel 7082, and accordingly the temperature difference of the refrigerant flowing through the first heat exchange channel 7082 can be calculated.
It can be understood that the refrigerant is closer to a liquid state as the refrigerant temperature difference is smaller, and the refrigerant can be considered to be in a gas-liquid two-phase state when the refrigerant temperature difference is smaller than the set temperature difference. The opening degree of the expansion valve 712 is adjusted and controlled according to the refrigerant temperature difference, and the refrigerant passing through the first heat exchange channel 7082 can be ensured to be in a gas-liquid two-phase state, so that the heat exchange of the refrigerant passing through the second heat exchange channel 7084 in the first heat exchange channel 7082 is improved, the enthalpy value in the first heat exchange channel 7082 can be increased, and the enthalpy increasing effect on the compressor 702 is improved.
In any of the above embodiments, the heat pump system 700 further comprises: the first pressure obtaining device 718 is disposed on the refrigerant pipeline between the exhaust port of the compressor 702 and the first heat exchanger 704.
In this embodiment, the heat pump system 700 further includes a first pressure obtaining device 718, and the first pressure obtaining device 718 is disposed on the refrigerant pipeline between the exhaust port of the compressor 702 and the first heat exchanger 704, and is capable of collecting a pressure value of the exhaust gas of the compressor 702.
Acquiring a discharge pressure value of the compressor 702, and acquiring a first temperature value at a refrigerant outlet of the first heat exchanger 704; and searching a corresponding saturation temperature value according to the exhaust pressure value, and determining the supercooling degree according to the saturation temperature value and the first temperature value. The method comprises the steps of obtaining a discharge pressure value of the compressor 702 and a first temperature value at a refrigerant outlet of the first heat exchanger 704, finding a saturation temperature value corresponding to the discharge pressure of the compressor 702 in a table look-up mode, and calculating the supercooling degree of the first heat exchanger 704 according to the saturation temperature value and the first temperature value. The supercooling degree of the first heat exchanger 704 calculated in the above manner is accurate, and the heat recovery amount of the economizer 708 and the injected refrigerant in a gas-liquid two-phase state can be ensured by controlling the refrigerant flow from the second heat exchange passage 7084 to the second heat exchanger 706 according to the supercooling degree calculated by the above formula.
In any of the above embodiments, the inlet of the second heat exchanging channel 7084 is connected to the refrigerant outlet of the first heat exchanger 704, and the heat pump system 700 further includes: a third temperature obtaining device 724 arranged at the outlet of the refrigerant of the first heat exchanger 704; the fourth temperature obtaining device 726 is disposed at an inlet of the refrigerant of the first heat exchanger 704.
In this embodiment, the refrigerant flowing out of the first heat exchanger 704 directly flows into the inlet of the second heat exchange passage 7084, and the refrigerant entering the second heat exchange passage 7084 can exchange heat with the refrigerant in the first heat exchange passage 7082. Since the refrigerant in the economical first heat exchange channel 7082 and the economical second heat exchange channel 7084 is liquid refrigerant, the heat exchange amount of the economizer 708 is increased, the refrigerant of the injection path is ensured to reach the optimal state, the heat recovery amount of the heat pump system 700 is increased, and the capacity and energy efficiency at low temperature are obviously improved.
The heat pump system 700 further comprises a third temperature obtaining device 724, a fourth temperature obtaining device 726. The third temperature obtaining device 724 is disposed at the refrigerant outlet of the first heat exchanger 704, the refrigerant directly enters the inlet of the second heat exchange channel 7084 of the economizer 708 after flowing out of the first heat exchanger 704, and the third temperature obtaining device 724 is capable of collecting the temperature of the refrigerant flowing out of the first heat exchanger 704. The fourth temperature obtaining device 726 is disposed at a refrigerant inlet of the first heat exchanger 704, and the fourth temperature obtaining device 726 is capable of collecting a temperature of a refrigerant flowing into the first heat exchanger 704.
In some embodiments, the flow rate of the refrigerant between the outlet of the second heat exchange passage 7084 and the second heat exchanger 706 is adjusted according to the supercooling degree. And controlling the flow of the refrigerant between the outlet of the second heat exchange channel 7084 and the second heat exchanger 706 according to the supercooling degree of the first heat exchanger 704. In the operation process of the heat pump system 700, the supercooling degree of the first heat exchanger 704 is continuously obtained, the flow rate of the refrigerant between the second heat exchangers 706 is controlled according to the obtained supercooling degree, the refrigerants in the first heat exchange channel and the second heat exchange channel in the economizer can be guaranteed to be liquid refrigerants, the refrigerant in the injection path is guaranteed to reach the optimal state, and the heat recovery capacity of the heat pump system 700 is improved.
Example five:
in a complete embodiment of the present invention, a method for controlling a heat pump system is provided, which is used to control the heat pump system in the fourth embodiment.
As shown in fig. 9, a control method for controlling a throttle member of a heat pump system includes:
step 902, controlling the heat pump system to start up in a heating mode;
904, acquiring the supercooling degree of the first heat exchanger, and determining the relation between the supercooling degree and a set supercooling degree interval;
step 906, controlling the throttling component to keep the current opening degree based on the supercooling degree in the target supercooling degree interval;
step 908, controlling the opening degree of the throttling component to increase based on the supercooling degree being more than or equal to the maximum value of the supercooling degree interval;
step 910, controlling the throttling component to reduce the opening degree based on the supercooling degree being less than or equal to the minimum value of the supercooling degree interval;
in step 912, the current state is maintained until the operation is finished.
In the embodiment, the throttling component is controlled according to the supercooling degree of the outlet of the first heat exchanger. And calculating to obtain the actual supercooling degree, comparing the actual supercooling degree with a target supercooling degree interval set by the system, and adjusting the throttling component according to the size relationship between the actual supercooling degree and the target supercooling degree interval.
And continuously acquiring the supercooling degree of the first heat exchanger, and when the supercooling degree is detected to be more than or equal to a first set supercooling degree, judging that the supercooling degree is overhigh at the moment, and controlling the throttle part to increase the opening degree. When the supercooling degree is detected to be less than or equal to the second set supercooling degree, the supercooling degree is judged to be too low, the expansion valve is controlled to reduce the opening degree, and the first set supercooling degree is greater than the second set supercooling degree. And when the obtained supercooling degree is within the numerical value range, judging that the opening degree of the throttling component does not need to be adjusted. The opening degree of the throttling component is adjusted through the supercooling degree of the outlet of the first heat exchanger, so that the heat recovery quantity of the economizer can be ensured, and the refrigerant at the injection port of the compressor is a gas-liquid two-phase refrigerant.
The step of obtaining the supercooling degree of the first heat exchanger specifically comprises the following steps: acquiring an exhaust pressure value of a compressor, and acquiring a first temperature value at a refrigerant outlet of a first heat exchanger; and searching a corresponding saturation temperature value according to the exhaust pressure value, and determining the supercooling degree according to the saturation temperature value and the first temperature value.
The supercooling degree of the first heat exchanger is obtained in a calculation mode, and the specific formula is as follows:
T sc ＝T C－ T 1 。
wherein, T sc Is super-cooling degree, T C Is the saturation temperature value, T 1 Is a first temperature value.
The method comprises the steps of obtaining an exhaust pressure value of a compressor and a first temperature value at a refrigerant outlet of a first heat exchanger, finding a saturation temperature value corresponding to the exhaust pressure of the compressor in a table look-up mode, and calculating the supercooling degree of the first heat exchanger according to the saturation temperature value and the first temperature value. The supercooling degree of the first heat exchanger calculated by the method is accurate, and the heat recovery amount of the economizer and the injected refrigerant in a gas-liquid two-phase state can be ensured by controlling the refrigerant flow from the second heat exchange channel to the second heat exchanger according to the supercooling degree calculated by the formula.
As shown in fig. 10, a method of controlling an expansion valve of a heat pump system includes:
step 1002, controlling a compressor to be in an injection enthalpy-increasing operation state;
step 1004, adjusting the opening degree of the expansion valve;
step 1006, judging whether the refrigerant temperature difference is less than the set temperature difference, if so, executing step 1008, and if not, returning to execute step 1004;
step 1008, judging whether the exhaust superheat degree is in a target exhaust superheat degree interval, if so, executing step 1010, and if not, returning to execute step 1004;
and step 1010, keeping the current state until the operation is finished.
In this embodiment, after the expansion valve is opened, the initial opening degree is small, the refrigerant flow of the injection path is small, the refrigerant in the first heat exchange channel in the economizer absorbs heat and turns into a gaseous state, and the refrigerant injected into the compressor is the gaseous refrigerant. The opening degree of the expansion valve is increased, the flow rate of the refrigerant of the injection path is gradually increased, the state of the refrigerant injected into the compressor is in a gas-liquid two-phase state, and the temperature difference of the refrigerant is gradually reduced in the valve opening process. When the temperature difference of the refrigerant is less than the set temperature difference, the refrigerant state can be judged to be a gas-liquid two-phase state, and the set temperature difference is 2 ℃. At this time, the state of the refrigerant at the injection port is almost optimal, and the expansion valve opening degree is optimal.
If the opening of the expansion valve is increased again, the flow of the injection path is increased, the power of the compressor is obviously increased, and the performance of the whole machine is reduced.
The heat pump system also comprises an expansion valve, and the expansion valve is arranged on a refrigerant pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel. The on-off state of the expansion valve is controlled, whether the refrigerant in the second heat exchange channel is guided into the first heat exchange channel can be controlled, and the opening degree of the expansion valve can be adjusted, so that the flow of the refrigerant entering the first heat exchange channel can be adjusted.
The step of adjusting the refrigerant flow in the first heat exchange channel according to the refrigerant temperature difference between the inlet and the outlet of the first heat exchange channel and the exhaust superheat degree comprises the following steps: and acquiring a target superheat degree interval and a set temperature difference, and adjusting the opening degree of the expansion valve according to the numerical relationship between the refrigerant temperature difference and the set temperature difference and the numerical relationship between the exhaust superheat degree and the target superheat degree interval. The refrigerant temperature difference can be smaller than the set temperature difference by adjusting the opening degree of the expansion valve, and the exhaust superheat degree is in a target exhaust superheat degree interval.
It can be understood that, if the temperature difference is smaller than the set temperature difference, it can be determined that the state of the refrigerant at this time is a gas-liquid two-phase refrigerant. On the other hand, in order to reduce the temperature difference, the opening degree of the expansion valve needs to be increased as much as possible, and in order to avoid an excessively large opening degree of the expansion valve and an excessively low degree of superheat of the exhaust gas from the compressor, the opening degree of the expansion valve is adjusted again in accordance with the degree of superheat of the exhaust gas. The refrigerant at the injection port is in a gas-liquid two-phase state on the premise of ensuring the stable operation of the compressor. The overall capacity and energy efficiency of the heat pump system are improved, and the running stability of the heat pump system is also ensured.
In the process of adjusting the opening degree of the expansion valve, the opening degree of the expansion valve needs to be adjusted according to the numerical relationship between the refrigerant temperature difference and the set temperature difference, and when the refrigerant temperature difference is lower than the set temperature difference, the opening degree of the expansion valve is adjusted according to the exhaust superheat degree of the compressor. In order to enable the refrigerant temperature difference to be lower than the set temperature difference, the opening degree of the expansion valve needs to be opened as large as possible, if the opening degree of the expansion valve is too large, the exhaust superheat degree of the compressor is too low, and therefore in the initial stage of operation of the heat pump system, the set temperature difference is adjusted to be lower than the set temperature difference through adjusting the expansion valve, and then the expansion valve is adjusted according to the exhaust superheat degree.
Specifically, after the heat pump system starts to operate and is in an operation state of increasing the enthalpy of the compressor, the refrigerant temperature difference of the first heat exchange channel is continuously collected, and when the refrigerant temperature difference is detected to be larger than a set temperature difference, the expansion opening degree is increased until the refrigerant temperature difference is smaller than the set temperature difference. Based on the working condition that the refrigerant temperature difference is smaller than the set temperature difference, the exhaust superheat degree of the compressor is obtained at the moment, the exhaust superheat degree is compared with a target exhaust superheat degree interval in a numerical value mode, when the exhaust superheat degree is smaller than the minimum value of the target exhaust superheat degree interval, the expansion valve is controlled to reduce the opening degree until the exhaust superheat degree is in the target exhaust superheat degree interval, the opening degree of the expansion valve is kept, and the refrigerant temperature difference and the exhaust superheat degree are continuously detected. In the subsequent operation, if the temperature difference of the refrigerant rises back to exceed the set temperature difference, the expansion valve is opened continuously, so that the state of the refrigerant flowing to the injection port of the compressor is a gas-liquid two-phase state. If the exhaust superheat degree of the compressor is not in the target exhaust superheat degree interval, the opening degree of the expansion valve is adjusted to enable the exhaust superheat degree to enter the target exhaust superheat degree interval, the stability of the operation of the compressor is guaranteed, and therefore the stability of the operation of the heat pump system is guaranteed.
Example six:
in still another embodiment of the present invention, a readable storage medium is provided, on which a program is stored, which when executed by a processor implements the control method of the heat pump system as in any of the above embodiments, thereby having all the advantageous technical effects of the control method of the heat pump system as in any of the above embodiments.
The readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.
It is to be understood that, in the claims, the specification and the drawings of the specification of the present invention, the term "plurality" means two or more, unless explicitly defined otherwise, the terms "upper", "lower", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for the purpose of more conveniently describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element so referred to must have the particular orientation described, be constructed in a particular orientation, and be operated, and thus the description should not be construed as limiting the present invention; the terms "connect," "mount," "secure," and the like are to be construed broadly, and for example, "connect" may refer to a fixed connection between multiple objects, a removable connection between multiple objects, or an integral connection; the multiple objects may be directly connected to each other or indirectly connected to each other through an intermediate. The specific meanings of the above terms in the present invention can be understood by those of ordinary skill in the art based on the above data.
In the claims, specification and drawings of the specification, the description of the term "one embodiment," "some embodiments," "specific embodiments," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In the claims, specification and drawings of the present application, schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (12)

1. A control method of a heat pump system is characterized in that the heat pump system comprises a compressor, a first heat exchanger, a second heat exchanger and an economizer, the economizer comprises a first heat exchange channel and a second heat exchange channel, an inlet of the first heat exchange channel is connected with an outlet of the second heat exchange channel, an outlet of the first heat exchange channel is connected with an injection port of the compressor, and an outlet of the second heat exchange channel is connected with the second heat exchanger, the control method comprises the following steps:
acquiring the supercooling degree of the first heat exchanger, the temperature difference of a refrigerant at an inlet and an outlet of the first heat exchange channel and the exhaust superheat degree of the compressor;
and adjusting the flow of the refrigerant between the outlet of the second heat exchange channel and the second heat exchanger according to the supercooling degree, and adjusting the flow of the refrigerant in the first heat exchange channel according to the temperature difference of the refrigerant and the exhaust superheat degree so as to enable the refrigerant flowing into the injection port of the compressor to be in a gas-liquid two-phase state.
2. The method for controlling a heat pump system according to claim 1, wherein the step of obtaining the supercooling degree of the first heat exchanger specifically includes:
acquiring an exhaust pressure value of the compressor, and acquiring a first temperature value at a refrigerant outlet of the first heat exchanger;
and searching for a corresponding saturation temperature value according to the exhaust pressure value, and determining the supercooling degree according to the saturation temperature value and the first temperature value.
3. The method of claim 2, wherein the heat pump system further includes a throttling component disposed in a pipeline between an outlet of the second heat exchange passage and the second heat exchanger, and the step of adjusting the refrigerant flow rate between the outlet of the second heat exchange passage and the second heat exchanger according to the supercooling degree includes:
controlling the throttle component to increase the opening degree based on the supercooling degree being greater than or equal to a first set supercooling degree;
and controlling the throttling component to reduce the opening degree based on the supercooling degree smaller than or equal to a second set supercooling degree, wherein the first set supercooling degree is larger than the second set supercooling degree.
4. The control method of the heat pump system according to any one of claims 1 to 3, characterized in that the heat pump system further includes: the expansion valve is arranged on a pipeline between an inlet of the first heat exchange channel and an outlet of the second heat exchange channel, and the step of adjusting the flow of the refrigerant in the first heat exchange channel according to the refrigerant temperature difference and the exhaust superheat degree specifically comprises the following steps:
acquiring a target exhaust superheat interval and a set temperature difference;
and adjusting the opening degree of the expansion valve to ensure that the temperature difference of the refrigerant is less than the set temperature difference and the exhaust superheat degree is within the target exhaust superheat degree interval.
5. The method for controlling a heat pump system according to claim 4, wherein the step of adjusting the opening degree of the expansion valve specifically includes:
controlling the expansion valve to increase the opening degree based on the refrigerant temperature difference being greater than or equal to a set temperature difference;
and determining that the exhaust superheat degree is smaller than the minimum value of the target exhaust superheat degree interval, and controlling the expansion valve to reduce the opening degree.
6. The method for controlling the heat pump system according to claim 4, wherein the step of obtaining the target exhaust superheat degree interval specifically includes:
acquiring a return air pressure value of the compressor and a discharge air pressure value of the compressor;
calculating according to the return air pressure value and the exhaust air pressure value to obtain a target exhaust superheat degree;
and determining the target exhaust superheat interval according to the target exhaust superheat.
7. A heat pump system, characterized in that, the heat pump system includes a compressor, a first heat exchanger and a second heat exchanger for forming a refrigerant circuit, the heat pump system further includes:
the economizer comprises a first heat exchange channel and a second heat exchange channel, wherein the inlet of the first heat exchange channel is connected with the outlet of the second heat exchange channel, the outlet of the first heat exchange channel is connected with the injection port of the compressor, and the outlet of the second heat exchange channel is connected with a second heat exchanger;
a memory having a program or instructions stored thereon;
a processor executing the program or instructions to carry out the steps of a method of controlling a heat pump system according to any one of claims 1 to 6.
8. The heat pump system of claim 7, further comprising:
the throttling component is arranged on a pipeline between the outlet of the second heat exchange channel and the second heat exchanger;
and the expansion valve is arranged on a pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel.
9. The heat pump system of claim 8, further comprising:
the first temperature acquisition device is arranged on a pipeline between the inlet of the first heat exchange channel and the outlet of the second heat exchange channel;
and the second temperature acquisition device is arranged at the outlet of the first heat exchange channel.
10. The heat pump system according to any one of claims 7-9, further comprising:
and the first pressure acquisition device is arranged on a refrigerant pipeline between the exhaust port of the compressor and the first heat exchanger.
11. The heat pump system of claim 7, wherein an inlet of the second heat exchange channel is connected to a refrigerant outlet of the first heat exchanger, the heat pump system further comprising:
the third temperature acquisition device is arranged at the outlet of the refrigerant of the first heat exchanger;
and the fourth temperature acquisition device is arranged at the inlet of the refrigerant of the first heat exchanger.
12. A readable storage medium, characterized in that the readable storage medium has stored thereon a program or instructions which, when executed by a processor, implement the steps of a method of controlling a heat pump system according to any one of claims 1 to 6.
CN202110229411.8A 2021-03-02 2021-03-02 Control method of heat pump system, heat pump system and readable storage medium Active CN114992907B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110229411.8A CN114992907B (en) 2021-03-02 2021-03-02 Control method of heat pump system, heat pump system and readable storage medium

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110229411.8A CN114992907B (en) 2021-03-02 2021-03-02 Control method of heat pump system, heat pump system and readable storage medium

Publications (2)

Publication Number Publication Date
CN114992907A true CN114992907A (en) 2022-09-02
CN114992907B CN114992907B (en) 2024-03-19

Family

ID=83018238

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110229411.8A Active CN114992907B (en) 2021-03-02 2021-03-02 Control method of heat pump system, heat pump system and readable storage medium

Country Status (1)

Country Link
CN (1) CN114992907B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108800562A (en) * 2018-06-20 2018-11-13 青岛海信日立空调系统有限公司 Heat-production control method, the apparatus and system of hot water heat pump system
CN109140826A (en) * 2018-08-13 2019-01-04 珠海格力电器股份有限公司 Enthalpy-increasing heat pump, air compensation amount control method and system thereof, computer equipment and storage medium
CN109798627A (en) * 2019-01-15 2019-05-24 广东美的暖通设备有限公司 The control method and device of multi-line system
CN110285598A (en) * 2019-06-28 2019-09-27 广东美的暖通设备有限公司 Air injection enthalpy-increasing air-conditioning system, method and air injection enthalpy-increasing air-conditioning and readable storage medium storing program for executing

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108800562A (en) * 2018-06-20 2018-11-13 青岛海信日立空调系统有限公司 Heat-production control method, the apparatus and system of hot water heat pump system
CN109140826A (en) * 2018-08-13 2019-01-04 珠海格力电器股份有限公司 Enthalpy-increasing heat pump, air compensation amount control method and system thereof, computer equipment and storage medium
CN109798627A (en) * 2019-01-15 2019-05-24 广东美的暖通设备有限公司 The control method and device of multi-line system
CN110285598A (en) * 2019-06-28 2019-09-27 广东美的暖通设备有限公司 Air injection enthalpy-increasing air-conditioning system, method and air injection enthalpy-increasing air-conditioning and readable storage medium storing program for executing

Also Published As

Publication number Publication date
CN114992907B (en) 2024-03-19

Similar Documents

Publication Publication Date Title
CN200996753Y (en) Refrigerating system of intermediate air-compensating compressor with economizer
CN109373497B (en) Refrigerant quantity adjusting method, device and system of temperature adjusting equipment and air conditioner
CN114322106B (en) Air conditioning system
CN211781668U (en) Partial heat recovery unit of ultra-low temperature air cooling module machine
CN110953757A (en) Liquid-spraying enthalpy-increasing heat pump unit and control method thereof
CN211372807U (en) Refrigerating system of semiconductor temperature control device
CN114992907B (en) Control method of heat pump system, heat pump system and readable storage medium
CN201265919Y (en) Air Conditioning system
CN116390430A (en) Multi-connected liquid cooling source
CN118189425A (en) Air supplementing and enthalpy increasing energy storage thermal management system for direct evaporation of intermediate refrigerant
CN112013472A (en) Air conditioner and control method thereof
CN116007242A (en) Energy storage heat management system using intermediate heat exchange of flash tank
CN214701327U (en) Centrifugal cascade high-pressure ratio series unit
CN113513852B (en) Cooling system, refrigeration equipment and cooling method
CN215765972U (en) Refrigerating system and condensing unit
CN215571358U (en) Compound refrigerating system with natural cooling function
EP3945266A1 (en) Refrigeration system and control method therefor
CN112880228B (en) Liquid return prevention device and method for air conditioner
CN110173934B (en) Control method of gas heat pump multi-split air conditioner supercooling structure
CN211120090U (en) Self-overlapping air source heat pump system for defrosting by utilizing low-boiling-point working medium hot gas
CN109539614B (en) Air conditioning system and energy adjusting method thereof
CN208075369U (en) A kind of air-conditioning refrigerator combined system of central refrigerating fission cooling
CN110762874A (en) Self-overlapping air source heat pump system for defrosting by utilizing low-boiling-point working medium hot gas
CN114992908B (en) Heat pump system, control method of heat pump system, and readable storage medium
CN218936733U (en) Air supplementing and enthalpy increasing energy storage heat management device with intermediate refrigerant cooling and evaporating at first

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant