CN106765524B - Outer unit control system, heat pump unit and control method thereof - Google Patents

Outer unit control system, heat pump unit and control method thereof Download PDF

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Publication number
CN106765524B
CN106765524B CN201611175066.XA CN201611175066A CN106765524B CN 106765524 B CN106765524 B CN 106765524B CN 201611175066 A CN201611175066 A CN 201611175066A CN 106765524 B CN106765524 B CN 106765524B
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temperature
throttling element
detected
preset
throttling
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CN106765524A (en
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马剑
张光鹏
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Midea Group Co Ltd
GD Midea Heating and Ventilating Equipment Co Ltd
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Midea Group Co Ltd
GD Midea Heating and Ventilating Equipment Co Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
    • F24D19/00—Details
    • F24D19/10—Arrangement or mounting of control or safety devices
    • F24D19/1006—Arrangement or mounting of control or safety devices for water heating systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
    • F24D15/00—Other domestic- or space-heating systems
    • F24D15/04—Other domestic- or space-heating systems using heat pumps
    • 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
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • 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
    • F24—HEATING; RANGES; VENTILATING
    • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
    • F24D2200/00—Heat sources or energy sources
    • F24D2200/12—Heat pump
    • F24D2200/123—Compression type heat pumps

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Sorption Type Refrigeration Machines (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The invention provides an external machine control system, a heat pump unit and a control method thereof, wherein the external machine control system comprises a refrigerant loop formed by connecting a compressor, a heat exchange element, a throttling device, a condenser and a separator in series, the throttling device comprises a throttling element A and at least one throttling element B connected with the throttling element A in series, the refrigerant loop is connected with a liquid spraying pipeline in parallel, the inlet end of the liquid spraying pipeline is arranged between the heat exchange element and the throttling device, the outlet end of the liquid spraying pipeline is arranged between the condenser and the separator, the liquid spraying pipeline is provided with a liquid spraying valve for controlling the flow of the pipeline, the external machine control system also comprises a controller for connecting the throttling device and the liquid spraying valve, the output capacity of the external machine is adjusted by controlling the flow of the refrigerant passing through the throttling device, so as to prolong the time of the water supply temperature reaching the maximum set temperature and further reduce the frequency of starting and, the water temperature of the water supply is ensured to be stable.

Description

Outer unit control system, heat pump unit and control method thereof
Technical Field
The invention relates to the technical field of heat exchange, in particular to an external unit control system, a heat pump unit and a control method thereof.
Background
Along with the continuous improvement of consciousness of people to the quality of life, in winter, more and more people can select the mode of utilizing ground heating to carry out heating. For a constant-speed air-cooled cold-hot water heat pump unit, when the unit works under a small load (such as the outdoor environment temperature of about 10 ℃), the outlet water temperature can quickly reach a preset value, and a compressor is continuously started and stopped, so that the water supply temperature fluctuation is large, and the indoor temperature cannot reach a comfortable temperature for a long time.
For the above situation, there are two solutions: (1) replacing a constant speed product with a variable frequency product, and reducing capacity output by using a variable frequency control technology; (2) the buffer water tank is connected in series to prolong the shutdown time when reaching the preset temperature and reduce the change of the water supply temperature after shutdown. However, the frequency conversion is adopted to replace a constant speed product, so that the cost is greatly increased; the buffer water tanks are connected in series, so that the cost is greatly increased, and extra building area is occupied.
Disclosure of Invention
The invention mainly aims to provide an external unit control system, and aims to solve the problem that the water supply temperature fluctuation is large due to frequent starting and stopping of a heat pump unit under a low-load working condition.
In order to achieve the purpose, the outdoor unit control system provided by the invention comprises a refrigerant loop formed by connecting a compressor, a heat exchange element, a throttling device, a condenser and a separator in series, wherein the throttling device comprises a throttling element A and at least one throttling element B connected with the throttling element A in series;
the refrigerant loop is connected in parallel with a liquid spraying pipeline, the liquid spraying pipeline comprises an inlet end and an outlet end, the inlet end is arranged on a pipeline between the heat exchange element and the throttling device, the outlet end is arranged on a pipeline between the condenser and the separator, and the liquid spraying pipeline is provided with a liquid spraying valve for controlling the flow of the pipeline;
the controller is connected with the liquid spraying valve and the throttling element of the throttling device, controls the flow of the refrigerant passing through the throttling device and the liquid spraying valve, and adjusts the output capacity of the external unit.
Further, the control system of the external unit further comprises a detection module, and when the external unit is detected to be stopped when the running time of the external unit is less than the preset value for at least two times, the water supply temperature reaches the maximum set temperature, the controller is started.
Further, the throttling device comprises a throttling element A and a first throttling element B connected with the throttling element A in series, the throttling element A and the first throttling element B are both connected with the controller, and the inlet end of the liquid spraying pipeline is arranged on a pipeline between the throttling element A and the heat exchange element.
Further, when T is detected to be [0, TS－Tn1) In the interval, the throttling element A is controlled to keep a preset opening degree, and the first throttling element B is controlled to keep a full opening degree;
when T is detectedTS－Tn1When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be gradually reduced;
when T ═ T is detectedSWhen the engine is started, the external machine stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn1Is a first preset temperature of water supply temperature, and T is more than 0S－Tn1＜TST is in [0, TS]In the interval, the heat output by the external unit is larger than the heat absorbed by the load.
Further, when T is detected to be [0, TS－Tn1) In the interval, the throttling element A is controlled to keep a preset opening degree, and the first throttling element B is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be gradually reduced;
when T ═ T is detectedS－Tn11When the current opening degree of the first throttling element B is kept for a first preset time, the first throttling element B is controlled to be increased to full opening;
when T ═ T is detectedSWhen the engine is started, the external machine stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn1A first preset temperature, T, of the temperature of the water supplyS－Tn11Is the first saturation temperature of the water supply temperature, and 0 < TS－Tn1＜TS－Tn11＜TSWhen T is equal to TS－Tn11When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.
Further, when T is detected to be [0, TS－Tn1) In the interval, the throttling element A is controlled to keep a preset opening degree, and the first throttling element B is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be gradually reduced;
when T ═ T is detectedS－Tn2When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be increased to full opening;
when T ═ T is detectedSWhen the engine is started, the external machine stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn2Is the first temperature after the temperature of the supplied water is reduced, TS－Tn1Is a first preset temperature of water supply temperature, and T is more than 0S－Tn2＜TS－Tn1＜TST is at slave TS－Tn1Down to TS－Tn2During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.
Further, when T is detectedP≥TPH－Tn1When the valve is opened, the liquid spraying valve is controlled to be opened;
when T is detectedP≤TPH－Tn2When the valve is closed, the liquid spraying valve is controlled to be closed;
wherein, 0 < TPH－Tn2＜TPH－Tn1＜TPH，TPTo exhaust temperature, TPHTo preset a maximum exhaust temperature, TPH－Tn1Presetting the temperature, T, for the first exhaustPH－Tn2A preset temperature for the second exhaust.
The invention further provides a heat pump unit, which comprises the external unit control system.
Another objective of the present invention is to provide a control method for a heat pump unit as described above, which includes the following steps:
when the outdoor unit is detected to be stopped when the water supply temperature reaches the highest set temperature when the running time is less than the preset value for at least two times, the following control logics are operated:
before the water supply temperature reaches a first preset temperature, controlling the throttling element A to keep a preset opening degree, and controlling all the throttling elements B to keep full opening;
when the water supply temperature is detected to reach a first preset temperature, controlling the opening degree of at least one throttling element B to gradually decrease;
when the exhaust temperature is detected to be higher than the first exhaust preset temperature, controlling the liquid spraying valve to be opened, and when the exhaust temperature is detected to be lower than the second exhaust preset temperature, controlling the liquid spraying valve to be closed;
when the water supply temperature is detected to reach the highest set temperature, the external machine stops, the liquid spraying valve is controlled to be closed, when the external machine is started again, the throttling elements A are controlled to be adjusted to the preset opening degree, and the opening degrees of all the throttling elements B are controlled to be adjusted to the maximum.
Further, the throttling device includes a throttling element a and a first throttling element B connected in series with the throttling element a, and the step of controlling the opening degree of at least one throttling element B to gradually decrease when the water supply temperature is detected to reach a first preset temperature specifically includes:
when the water supply temperature is detected to reach a first preset temperature, controlling the opening degree of the first throttling element B to gradually decrease;
when the water supply temperature is detected not to rise any more, the heat output by the external machine is equal to the heat absorbed by the load, and the first throttling element B is controlled to be opened fully after the current opening degree is kept for a first preset time;
and when the water supply temperature is detected to be reduced, the heat output by the external machine is smaller than the heat absorbed by the load, and the opening degree of the first throttling element B is controlled to be increased to full open.
The invention relates to an external machine control system, which comprises a refrigerant loop formed by connecting a compressor, a heat exchange element, a throttling device, a condenser and a separator in series, the throttling device comprises a throttling element A and at least one throttling element B connected with the throttling element A in series, the refrigerant loop is connected with a liquid spraying pipeline in parallel, the inlet end of the liquid spraying pipeline is arranged between the heat exchange element and the throttling device, the outlet end of the liquid spraying pipeline is arranged between the condenser and the separator, the liquid spraying pipeline is provided with a liquid spraying valve for controlling the flow of the pipeline, the outer machine control system also comprises a controller for connecting the throttling device and the liquid spraying valve, the output capacity of the external unit is adjusted by controlling the flow of the refrigerant passing through the throttling device and the liquid spraying valve, the time that the water supply temperature reaches the highest set temperature is prolonged, so that the frequency of starting and stopping the outdoor unit at a temperature is reduced, and the stability of the water supply temperature is ensured.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an embodiment of an external machine control system according to the present invention;
FIG. 2 is a control logic diagram of the control system of the peripheral of FIG. 1;
fig. 3 is a flowchart of an embodiment of a method for controlling a heat pump unit according to the present invention.
The reference numbers illustrate:
reference numerals Name (R) Reference numerals Name (R)
10 Outdoor machine 152 First throttling element B
11 Compressor with a compressor housing having a plurality of compressor blades 20 Refrigerant pipeline
12 Separator 21 Liquid spraying pipeline
13 Condenser 211 Liquid spraying valve
15 Throttle device 30 Heat exchange element
151 Throttling element A 40 Heating loop
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides an external unit control system which is applied to a heat pump unit.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of an external machine control system according to the present invention.
In the above embodiment, the outdoor unit control system includes the refrigerant loop 20 formed by connecting the compressor 11, the heat exchange element 30, the throttling device 15, the condenser 13, and the separator 12 in series, where the throttling device 15 includes the throttling element a151 and at least one throttling element B connected in series with the throttling element a 151;
the refrigerant loop 20 is connected in parallel with a liquid spraying pipeline 21, the liquid spraying pipeline 21 comprises an inlet end and an outlet end, the inlet end is arranged on a pipeline between the heat exchange element 30 and the throttling device 15, the outlet end is arranged on a pipeline between the condenser 13 and the separator 12, and the liquid spraying pipeline 21 is provided with a liquid spraying valve 211 for controlling the flow of the pipeline;
the outdoor unit control system further includes a controller (not shown) connected to the liquid discharge valve 211 and the throttling element of the throttling device 15, and configured to control the flow rate of the refrigerant passing through the throttling device 15 and the liquid discharge valve 211 and to adjust the output capacity of the outdoor unit 10.
In this embodiment, the outdoor unit control system is mainly used for controlling the output and temperature of a high-temperature and high-pressure gaseous refrigerant in a refrigerant loop 20 formed by connecting the compressor 11, the heat exchange element 30, the throttling device 15, the condenser 13 and the separator 12 in series, and controlling the flow rate and temperature of the refrigerant to adjust the change rate of the supply water temperature, thereby prolonging the operation time of the outdoor unit 10 composed of the compressor 11, the separator 12 and the condenser 13 and reducing the start-stop frequency thereof.
Further, the control system of the outdoor unit further includes a detection module (not shown) for starting the controller when the outdoor unit 10 is stopped when the supply water temperature reaches the maximum set temperature when the operation time is less than the preset value at least twice continuously.
In this embodiment, the control system of the external unit further includes a detection module for detecting the temperature of the supplied water, where the detection module may be a temperature sensor or an electronic thermometer connected to the electronic control system, so that when the external unit 10 is detected to be stopped when the operation time is less than the preset value at least once and the temperature of the supplied water reaches the maximum set value, the controller is started to enter the control logic, and the operation process of the external unit 10 in the next cycle is adjusted.
Further, referring to fig. 1, the throttling device 15 includes a throttling element a151 connected in series and a first throttling element B152 connected in series with the throttling element a151, both the throttling element a151 and the first throttling element B152 are connected to the controller, an inlet end of the liquid injection pipeline 21 is disposed in a pipeline between the throttling element a151 and the heat exchange element 30, and the controller controls opening degrees of the throttling element a151 and the first throttling element B152 to adjust an amount of refrigerant entering the condenser 13 and adjust an output amount of high-temperature and high-pressure refrigerant, so as to ensure stable water temperature of the supplied water.
Further, referring to FIGS. 1 and 2, when T is detected to be [0, TS－Tn1) In the interval, the throttling element A151 is controlled to keep a preset opening degree, and the first throttling element B152 is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the opening degree of the first throttling element B152 is controlled to be gradually reduced;
when T ═ T is detectedSWhen the engine is started, the outdoor unit 10 stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn1Is a first preset temperature of water supply temperature, and T is more than 0S－Tn1＜TST is in [0, TS]In the interval, the heat output by the external unit is larger than the heat absorbed by the load.
In this embodiment, the external unit 10 enters the control logic as shown in fig. 2 when turned on again, the detection module detects the water supply temperature T, and the water supply temperature T does not reach the first preset temperature TS－Tn1Before, the controller controls the first throttling element B152 to be fully opened, the throttling element a151 system is automatically adjusted to a preset opening degree, so that the maximum refrigerant quantity in the refrigerant loop 20 absorbs heat from the external environment in the condenser 13 and is evaporated into a gaseous refrigerant, the gaseous refrigerant with high temperature and high pressure is output after entering the compressor 11, heat exchange is realized between the gaseous refrigerant with high pressure and the water to be heated in the heating loop 40 in the heat exchange element 30, and the water supply temperature quickly reaches the first preset temperature TS－Tn1When the water supply temperature T reaches a first preset temperature TS－Tn1In order to prolong the operation time of the outer unit 10, the opening degree of the first throttling element B152 is controlled to be gradually reduced, the opening degree of the throttling element a151 is kept unchanged, so as to reduce the flow rate of the gaseous refrigerant entering the compressor 11 and reduce the rising rate of the water supply temperature T, and generally, if the opening degree of the first throttling element B152 is continuously reduced, the heat output by the outer unit 10 is still larger than the heat absorbed by the heating load, that is, T is [0, T [, ] TS]In intervals of timeThe heat output by the outdoor unit is always greater than the heat absorbed by the heating load, and the water supply temperature T can continuously rise until the maximum set temperature T is reachedSWhen the outdoor unit 10 is stopped, the opening degree of the first throttling element B152 is decreased, and then a small amount of refrigerant in the refrigerant circuit 20, which is subjected to heat exchange, absorbs a large amount of external heat, thereby increasing the discharge temperature TPReaches a first preset exhaust temperature TPH－Tn1To avoid reaching T due to exhaust gas temperaturePHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant is input to reduce the exhaust temperature, and the exhaust temperature T is detectedPReducing to a second preset exhaust temperature TPH－Tn2When the pressure is higher than the preset pressure, the liquid spraying valve 211 is controlled to be closed, wherein T is more than 0PH－Tn2＜TPH－Tn1＜TPH，TPTo exhaust temperature, TPHIs a preset maximum exhaust temperature.
Further, referring to FIGS. 1 and 2, when T is detected to be [0, TS－Tn1) In the interval, the throttling element A151 is controlled to keep a preset opening degree, and the first throttling element B152 is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the opening degree of the first throttling element B152 is controlled to be gradually reduced;
when T ═ T is detectedS－Tn11When the current opening degree is maintained for the first preset time, the first throttling element B152 is controlled to be increased to full opening;
when T ═ T is detectedSWhen the engine is started, the outdoor unit 10 stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn1A first preset temperature, T, of the temperature of the water supplyS－Tn11Is the first saturation temperature of the water supply temperature, and 0 < TS－Tn1＜TS－Tn11＜TSWhen T is equal to TS－Tn11When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.
In this embodiment, when the outdoor unit 10 is turned on again, the control logic shown in fig. 2 is entered, and the detection module detects the temperature of the supplied waterDetecting the temperature T, and detecting when the water supply temperature T does not reach a first preset temperature TS－Tn1Before, the controller controls the first throttling element B152 to be fully opened, the throttling element a151 system is automatically adjusted to a preset opening degree, so that the maximum refrigerant quantity in the refrigerant loop 20 absorbs heat from the external environment in the condenser 13 and is evaporated into a gaseous refrigerant, the gaseous refrigerant with high temperature and high pressure is output after entering the compressor 11, heat exchange is realized between the gaseous refrigerant with high pressure and the water to be heated in the heating loop 40 in the heat exchange element 30, and the water supply temperature quickly reaches the first preset temperature TS－Tn1When the water supply temperature T reaches a first preset temperature TS－Tn1Meanwhile, in order to extend the operation time of the outer unit 10, the opening degree of the first throttling element B152 is controlled to be gradually decreased, and the opening degree of the throttling element a151 is kept unchanged to decrease the flow rate of the gaseous refrigerant entering the compressor 11, decrease the rising rate of the feed water temperature T, and rise to the first saturation temperature T of the feed water temperature T at the feed water temperature TS－Tn11When the temperature of the water supply is higher than the preset temperature T, the first throttling element B152 is opened to a full state after the first throttling element B152 is opened for a first preset time, the opening system of the throttling element a151 is automatically adjusted, the output heat of the outdoor unit 10 is higher than the heat absorbed by the heating load, and the water supply temperature T is increased until the maximum set temperature T is reachedSWhen the outdoor unit 10 is stopped, the opening degree of the first throttling element B152 is decreased, and then a small amount of refrigerant in the refrigerant circuit 20, which is subjected to heat exchange, absorbs a large amount of external heat, thereby increasing the discharge temperature TPReaches a first preset exhaust temperature TPH－Tn1To avoid reaching T due to exhaust gas temperaturePHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant is input to reduce the exhaust temperature, and the exhaust temperature T is detectedPReducing to a second preset exhaust temperature TPH－Tn2When the pressure is higher than the preset pressure, the liquid spraying valve 211 is controlled to be closed, wherein T is more than 0PH－Tn2＜TPH－Tn1＜TPH，TPTo exhaust temperature, TPHIs a preset maximum exhaust temperature.
Further, referring to FIGS. 1 and 2, when T is detected to be [0, TS－Tn1) In the interval, the throttling element A151 is controlled to keep a preset opening degree, and the first throttling element B152 is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the opening degree of the first throttling element B152 is controlled to be gradually reduced;
when T ═ T is detectedS－Tn2When the first throttling element B152 is opened, the opening degree of the first throttling element B152 is controlled to be increased to full opening;
when T ═ T is detectedSWhen the engine is started, the outdoor unit 10 stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn2Is the first temperature after the temperature of the supplied water is reduced, TS－Tn1Is a first preset temperature of water supply temperature, and T is more than 0S－Tn2＜TS－Tn1＜TST is at slave TS－Tn1Down to TS－Tn2During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.
In this embodiment, the external unit 10 enters the control logic as shown in fig. 2 when turned on again, the detection module detects the water supply temperature T, and the water supply temperature T does not reach the first preset temperature TS－Tn1Before, the controller controls the first throttling element B152 to be fully opened, the throttling element a151 system is automatically adjusted to a preset opening degree, so that the maximum refrigerant quantity in the refrigerant loop 20 absorbs heat from the external environment in the condenser 13 and is evaporated into a gaseous refrigerant, the gaseous refrigerant with high temperature and high pressure is output after entering the compressor 11, heat exchange is realized between the gaseous refrigerant with high pressure and the water to be heated in the heating loop 40 in the heat exchange element 30, and the water supply temperature quickly reaches the first preset temperature TS－Tn1When the water supply temperature T reaches a first preset temperature TS－Tn1Meanwhile, in order to extend the operation time of the outer unit 10, the opening degree of the first throttling element B152 is controlled to be gradually reduced, the opening degree of the throttling element a151 is kept unchanged to reduce the flow rate of the gaseous refrigerant entering the compressor 11, and the rising rate of the feed water temperature T is reduced, wherein the opening degree of the first throttling element B152 is gradually reduced from full opening to small openingDuring the adjustment, when the supply water temperature T is reduced to a first temperature T after the supply water temperature is reducedS－Tn2In this case, the heat output from the outdoor unit 10 is smaller than the heat absorbed by the heating load, and T ═ T is detected to stabilize the supply water temperatureS－Tn2When the opening degree of the first throttling element B152 is controlled to be increased, the output heat of the outer unit 10 is again larger than the heat absorbed by the heating load, the feed water temperature T is increased, and T ═ T is detectedS－Tn1When the opening degree of the first throttling element B152 is controlled to be gradually reduced, the opening degree of the throttling element A151 is kept unchanged, and when T is detected to be T ═ TS－Tn11When the current opening degree of the first throttling element B152 is maintained for a first preset time, the first throttling element B is controlled to be increased to be fully opened, and the opening degree of the throttling element A151 is automatically adjusted by a system; if the balance point of the output and the load of the external machine cannot be obtained, after the operation is repeatedly carried out for the second preset time, the opening degree of the first throttling element B152 is increased to be fully opened, the opening degree of the throttling element A151 is automatically adjusted by the system, and the water supply temperature T can continuously rise until the maximum set temperature T is reachedSWhen the outdoor unit 10 is stopped, the opening degree of the first throttling element B152 is decreased, and then a small amount of refrigerant in the refrigerant circuit 20, which is subjected to heat exchange, absorbs a large amount of external heat, thereby increasing the discharge temperature TPReaches a first preset exhaust temperature TPH－Tn1To avoid reaching T due to exhaust gas temperaturePHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant is input to reduce the exhaust temperature, and the exhaust temperature T is detectedPReducing to a second preset exhaust temperature TPH－Tn2When the pressure is higher than the preset pressure, the liquid spraying valve 211 is controlled to be closed, wherein T is more than 0PH－Tn2＜TPH－Tn1＜TPH，TPTo exhaust temperature, TPHIs a preset maximum exhaust temperature.
The invention also provides a heat pump unit which comprises the external unit control system.
Referring to fig. 1, the heat pump unit of this embodiment includes the above-mentioned external unit control system, the external unit control system includes a refrigerant loop 20 formed by connecting a compressor 11, a heat exchange element 30, a throttling device 15, a condenser 13, and a separator 12 in series, the throttling device 15 includes a throttling element a151 and at least one throttling element B connected in series with the throttling element a151, the refrigerant loop 20 is connected in parallel with a liquid injection pipeline 21, an inlet end of the liquid injection pipeline 21 is disposed between the heat exchange element 30 and the throttling device 15, an outlet end of the liquid injection pipeline is disposed between the condenser 13 and the separator 12, the liquid injection pipeline 21 is provided with a liquid injection valve 211 for controlling a flow rate of the pipeline, the external unit control system further includes a controller for connecting the throttling element of the throttling device 15 and the liquid injection valve 211, and adjusts a refrigerant flow rate in the refrigerant loop 20 by controlling an opening of the liquid injection valve 211 and an opening degree of the throttling element, and then the change rate of the water supply temperature is controlled, the running time of the external unit 10 is prolonged, the starting and stopping frequency of the external unit is reduced, and the stability of the water supply temperature is ensured.
The invention further provides a control method of the heat pump unit.
Referring to fig. 3, fig. 3 is a flowchart of an embodiment of a control method of a heat pump unit according to the present invention.
In this embodiment, the method for controlling the heat pump unit includes the following steps:
s10: when the outdoor unit is detected to be stopped when the water supply temperature reaches the highest set temperature when the running time is less than the preset value for at least two times, the following control logics are operated:
s11: before the water supply temperature reaches a first preset temperature, controlling the throttling element A to keep a preset opening degree, and controlling all the throttling elements B to keep full opening;
s12: when the water supply temperature is detected to reach a first preset temperature, controlling the opening degree of at least one throttling element B to gradually decrease;
s13: when the exhaust temperature is detected to be higher than the first exhaust preset temperature, controlling the liquid spraying valve to be opened, and when the exhaust temperature is detected to be lower than the second exhaust preset temperature, controlling the liquid spraying valve to be closed;
s14: when the water supply temperature is detected to reach the highest set temperature, the external machine stops, the liquid spraying valve is controlled to be closed, when the external machine is started again, the throttling elements A are controlled to be adjusted to the preset opening degree, and the opening degrees of all the throttling elements B are controlled to be adjusted to the maximum.
Before the water supply temperature reaches a first preset temperature, the controller controls the first throttling element B152 to be kept fully open, the throttling element A151 is automatically adjusted to a preset opening degree by a system, so that the maximum refrigerant quantity in the refrigerant loop 20 absorbs heat from the external environment in the condenser 13 to be evaporated into gaseous refrigerant, the gaseous refrigerant with high temperature and high pressure is output after entering the compressor 11 to exchange heat with the water to be heated in the heating loop 40 in the heat exchange element 30, the preset first water supply temperature is reached, preliminary heating is realized, in order to prolong the running time of the outer unit 10 and delay the speed of reaching the maximum set temperature of the water supply temperature, when the water supply temperature is detected to reach the first preset temperature, the opening degree of at least one throttling element B is controlled to be gradually reduced so as to reduce the refrigerant flow passing through the throttling device 15 and further reduce the refrigerant flow entering the compressor 11, and if a small amount of heat exchange in the refrigerant loop 20 absorbs a large amount of external heat at the moment, so that exhaust gas is Temperature TPReaches a first preset exhaust temperature TPH－Tn1To avoid reaching T due to exhaust gas temperaturePHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant is input to reduce the exhaust temperature, and the exhaust temperature T is detectedPReducing to a second preset exhaust temperature TPH－Tn2When the pressure is high, the liquid discharge valve 211 is controlled to be closed. If the heat output by the external unit 10 is still greater than the heat absorbed by the heating load, the water supply temperature continues to rise, when the water supply temperature reaches the maximum set temperature, the external unit 10 is automatically stopped, when the external unit 10 is detected to be restarted, the throttling element A is controlled to be adjusted to the preset opening, the openings of all the throttling elements B are controlled to be adjusted to the maximum, and next control logic circulation is carried out.
Further, referring to fig. 3, the throttling device includes a throttling element a and a first throttling element B connected in series with the throttling element a, and step S12 specifically includes:
when the water supply temperature is detected to reach a first preset temperature, controlling the opening degree of the first throttling element B to gradually decrease;
when the water supply temperature is detected not to rise any more, the heat output by the external machine is equal to the heat absorbed by the load, and the first throttling element B is controlled to be opened fully after the current opening degree is kept for a first preset time;
and when the water supply temperature is detected to be reduced, the heat output by the external machine is smaller than the heat absorbed by the load, and the opening degree of the first throttling element B is controlled to be increased to full open.
In the present embodiment, with further reference to fig. 1 and 2, the throttling device 15 includes a throttling element a151 and a first throttling element B152 connected in series with the throttling element a151, and when it is detected that the temperature of the supplied water reaches a first preset temperature, the opening degree of the first throttling element B152 is controlled to be adjusted from full opening to small opening, and the opening degree of the throttling element a151 is kept unchanged; if the refrigerant in the refrigerant circuit 20 is less to take part in the heat exchange, a large amount of external heat is absorbed to make the exhaust temperature TPReaches a first preset exhaust temperature TPH－Tn1To avoid reaching T due to exhaust gas temperaturePHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant is input to reduce the exhaust temperature, and the exhaust temperature T is detectedPReducing to a second preset exhaust temperature TPH－Tn2When the pressure is high, the liquid spraying valve 211 is controlled to be closed; if the heat output by the outer machine 10 is still greater than the heat absorbed by the heating load, the water supply temperature will continue to rise, and when the water supply temperature is detected not to rise any more, the heat output by the outer machine 10 is equal to the heat absorbed by the heating load, in order to ensure the efficient operation of the outer machine 10, the first throttling element B152 is controlled to maintain the current opening degree for a first preset time and then is increased to be fully open, and the opening degree of the throttling element a151 is automatically adjusted by the system, so that the outer machine 10 is stopped when the water supply temperature reaches the highest set temperature, and the normal start and stop of the outer machine 10 are ensured; if the output heat of the outer unit 10 is smaller than the heat absorbed by the heating load after the opening degree of the first throttling element B152 is decreased, the supply water temperature is decreased, and when the decrease in the supply water temperature is detected, the opening degree of the first throttling element B152 is controlled to be increased, so that the supply water temperature is increasedThe temperature T is increased, when the water supply temperature is detected to reach a first preset temperature, the opening degree of the first throttling element B152 is controlled to be gradually reduced, the opening degree of the throttling element A151 is kept unchanged, when the water supply temperature is detected not to be increased any more, the first throttling element B152 is controlled to be kept at the current opening degree for a first preset time and then is controlled to be increased to be fully opened, and the opening degree of the throttling element A151 is automatically adjusted by a system; if the balance point of the output and the load of the external machine is not obtained, after the operation is repeatedly performed for the second preset time, the opening degree of the first throttling element B152 is increased to be fully opened so as to ensure that the water supply temperature is kept within the preset temperature range.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (8)

1. An outdoor unit control system comprises a refrigerant loop formed by connecting a compressor, a heat exchange element, a throttling device, a condenser and a separator in series, and is characterized in that the throttling device comprises a throttling element A and at least one first throttling element B connected with the throttling element A in series;
the refrigerant loop is connected in parallel with a liquid spraying pipeline which comprises an inlet end and an outlet end, the inlet end is arranged on a pipeline between the heat exchange element and the throttling element A, the outlet end is arranged on a pipeline between the condenser and the separator, and the liquid spraying pipeline is provided with a liquid spraying valve for controlling the flow of the pipeline;
the outdoor unit control system also comprises a controller and a detection module, wherein the controller is connected with the liquid spraying valve and a throttling element of the throttling device, controls the flow of a refrigerant passing through the throttling device and the liquid spraying valve, and adjusts the output capacity of the outdoor unit, and the throttling element A and the first throttling element B are both connected with the controller; and the detection module detects that the running time of the external unit is less than the preset value at least twice continuously, the water supply temperature reaches the highest set temperature and the external unit is shut down, and then the controller is started.
2. The outdoor unit control system according to claim 1,
when T is detected to be [0, TS－Tn1) In the interval, the throttling element A is controlled to keep a preset opening degree, and the first throttling element B is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be gradually reduced;
when T ═ T is detectedSWhen the engine is started, the external machine stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn1Is a first preset temperature of water supply temperature, and T is more than 0S－Tn1＜TST is in [0, TS]In the interval, the heat output by the external unit is larger than the heat absorbed by the load.
3. The outdoor unit control system according to claim 1,
when T is detected to be [0, TS－Tn1) In the interval, the throttling element A is controlled to keep a preset opening degree, and the first throttling element B is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be gradually reduced;
when T ═ T is detectedS－Tn11When the current opening degree of the first throttling element B is kept for a first preset time, the first throttling element B is controlled to be increased to full opening;
when T ═ T is detectedSWhen the engine is started, the external machine stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn1A first preset temperature, T, of the temperature of the water supplyS－Tn11Is the first saturation temperature of the water supply temperature, and 0 < TS－Tn1＜TS－Tn11＜TSWhen T is equal to TS－Tn11When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.
4. The outdoor unit control system according to claim 1,
when T is detected to be [0, TS－Tn1) In the interval, the throttling element A is controlled to keep a preset opening degree, and the first throttling element B is controlled to keep a full opening degree;
when T ═ T is detectedS－Tn1When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be gradually reduced;
when T ═ T is detectedS－Tn2When the first throttling element B is opened, the opening degree of the first throttling element B is controlled to be increased to full opening;
when T ═ T is detectedSWhen the engine is started, the external machine stops;
wherein T is the temperature of the supplied water, TSTo the maximum set temperature, TS－Tn2Is the first temperature after the temperature of the supplied water is reduced, TS－Tn1Is a first preset temperature of water supply temperature, and T is more than 0S－Tn2＜TS－Tn1＜TST is at slave TS－Tn1Down to TS－Tn2During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.
5. The outdoor unit control system according to any one of claims 1 to 4,
when T is detectedP≥TPH－Tn1When the valve is opened, the liquid spraying valve is controlled to be opened;
when T is detectedP≤TPH－Tn2When the valve is closed, the liquid spraying valve is controlled to be closed;
wherein, 0 < TPH－Tn2＜TPH－Tn1＜TPH，TPTo exhaust temperature, TPHTo preset a maximum exhaust temperature, TPH－Tn1Presetting the temperature, T, for the first exhaustPH－Tn2A preset temperature for the second exhaust.
6. A heat pump unit comprising the external unit control system according to claim 5.
7. A control method for a heat pump unit according to claim 6, characterized in that the control method comprises the following steps:
when the outdoor unit is detected to be stopped when the water supply temperature reaches the highest set temperature when the running time is less than the preset value for at least two times, the following control logics are operated:
before the water supply temperature reaches a first preset temperature, controlling the throttling element A to keep a preset opening degree, and controlling all the throttling elements B to keep full opening;
when the water supply temperature is detected to reach a first preset temperature, controlling the opening degree of at least one throttling element B to gradually decrease;
when the exhaust temperature is detected to be greater than or equal to a first exhaust preset temperature, controlling the liquid spraying valve to be opened, and when the exhaust temperature is detected to be less than or equal to a second exhaust preset temperature, controlling the liquid spraying valve to be closed;
when the water supply temperature is detected to reach the highest set temperature, the external machine stops, the liquid spraying valve is controlled to be closed, when the external machine is started again, the throttling elements A are controlled to be adjusted to the preset opening degree, and the opening degrees of all the throttling elements B are controlled to be adjusted to the maximum.
8. The heat pump unit control method according to claim 7, wherein the throttling device includes a throttling element A and a first throttling element B connected in series with the throttling element A, and the step of controlling the opening of at least one throttling element B to gradually decrease when the supply water temperature is detected to reach a first preset temperature specifically includes:
when the water supply temperature is detected to reach a first preset temperature, controlling the opening degree of the first throttling element B to gradually decrease;
when the water supply temperature is detected not to rise any more, the heat output by the external machine is equal to the heat absorbed by the load, and the first throttling element B is controlled to be opened fully after the current opening degree is kept for a first preset time;
and when the water supply temperature is detected to be reduced, the heat output by the external machine is smaller than the heat absorbed by the load, and the opening degree of the first throttling element B is controlled to be increased to full open.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102705964A (en) * 2012-05-22 2012-10-03 Tcl空调器(中山)有限公司 Air conditioner and control method thereof
CN203964434U (en) * 2014-03-27 2014-11-26 广东美的暖通设备有限公司 Heat pump air conditioner
CN104807229A (en) * 2015-04-27 2015-07-29 广东美的暖通设备有限公司 Multi-split air conditioner and control method thereof
CN106247652A (en) * 2016-09-29 2016-12-21 广东美的制冷设备有限公司 Air conditioning system and control method thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7178362B2 (en) * 2005-01-24 2007-02-20 Tecumseh Products Cormpany Expansion device arrangement for vapor compression system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102705964A (en) * 2012-05-22 2012-10-03 Tcl空调器(中山)有限公司 Air conditioner and control method thereof
CN203964434U (en) * 2014-03-27 2014-11-26 广东美的暖通设备有限公司 Heat pump air conditioner
CN104807229A (en) * 2015-04-27 2015-07-29 广东美的暖通设备有限公司 Multi-split air conditioner and control method thereof
CN106247652A (en) * 2016-09-29 2016-12-21 广东美的制冷设备有限公司 Air conditioning system and control method thereof

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