CN106595126B

CN106595126B - Outer unit control system, heat pump unit and control method thereof

Info

Publication number: CN106595126B
Application number: CN201611175068.9A
Authority: CN
Inventors: 马剑; 张光鹏
Original assignee: Midea Group Co Ltd; GD Midea Heating and Ventilating Equipment Co Ltd
Current assignee: Midea Group Co Ltd; GD Midea Heating and Ventilating Equipment Co Ltd
Priority date: 2016-12-16
Filing date: 2016-12-16
Publication date: 2019-12-20
Anticipated expiration: 2036-12-16
Also published as: CN106595126A

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 main path throttling element and at least one branch path throttling element connected with the main path throttling element in parallel, the branch path throttling element is connected with an electromagnetic valve 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, the external machine control system also comprises a controller, the flow and the temperature of the refrigerant entering the compressor are adjusted by controlling the opening and closing of the electromagnetic valve and the liquid spraying valve, and further the output capacity of an external machine is adjusted to prolong the time of, thereby reducing the frequency of the external unit to warm start and stop and ensuring the stability of water supply temperature.

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, and is characterized in that the throttling device comprises a main path throttling element and at least one branch path throttling element connected with the main path throttling element in parallel, and the branch path throttling element is connected with an electromagnetic valve 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 outer machine control system further comprises a controller, wherein the controller is connected with the liquid spraying valve and the electromagnetic valve, controls the liquid spraying valve and the electromagnetic valve to be opened and closed, and adjusts the output capacity of the outer machine.

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 first branch throttling element and a second branch throttling element which are connected with the main branch throttling element in parallel, a first electromagnetic valve connected with the first branch throttling element in series, and a second electromagnetic valve connected with the second branch throttling element in series, wherein the first electromagnetic valve and the second electromagnetic valve are connected with the controller.

Further, the method can be used for preparing a novel materialWhen detecting that T is [0, T_S－T_n3) During interval, controlling the first electromagnetic valve and the second electromagnetic valve to be kept open;

when T ═ T is detected_S－T_n3When the first electromagnetic valve or the second electromagnetic valve is closed, the first electromagnetic valve or the second electromagnetic valve is controlled to be closed;

when T ═ T is detected_S－T_n1When the first electromagnetic valve or the second electromagnetic valve in the non-closed state is controlled to be closed;

when T ═ T is detected_SWhen the engine is started, the external machine stops;

wherein T is the temperature of the supplied water, T_STo the maximum set temperature, T_S－T_n3A first preset temperature, T, of the temperature of the water supply_S－T_n1A second preset temperature of water supply temperature, and T is more than 0_S－T_n3＜T_S－T_n1＜T_ST is in [0, T_S]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, T_S－T_n3) During interval, controlling the first electromagnetic valve and the second electromagnetic valve to be kept open;

when T ═ T is detected_S－T_n31When the electromagnetic valve is opened, the first electromagnetic valve or the second electromagnetic valve which is controlled to be closed is kept closed for a first preset time and then opened;

wherein T is the temperature of the supplied water, T_STo the maximum set temperature, T_S－T_n3A first preset temperature, T, of the temperature of the water supply_S－T_n31A first saturation temperature of 0 < T_S－T_n3＜T_S－T_n31＜T_S，

At T ═ T_S－T_n31When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.

when T ═ T is detected_S－T_n1When the electromagnetic valve is opened, the first electromagnetic valve or the second electromagnetic valve which is controlled to be opened is closed;

when T ═ T is detected_S－T_n11When the first electromagnetic valve and the second electromagnetic valve are controlled to be closed for a second preset time, the first electromagnetic valve and/or the second electromagnetic valve are controlled to be opened;

wherein T is the temperature of the supplied water, T_STo the maximum set temperature, T_S－T_n3A first preset temperature, T, of the temperature of the water supply_S－T_n1A second preset temperature, T, for the temperature of the water supply_S－T_n11A second saturation temperature of 0 < T_S－T_n3＜T_S－T_n1＜T_S－T_n11＜T_SWhen T is equal to T_S－T_n11When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.

when T ═ T is detected_S－T_n2When the first electromagnetic valve and/or the second electromagnetic valve are/is controlled to be opened;

wherein T is the temperature of the supplied water, T_STo the maximum set temperature, T_S－T_n3A first preset temperature, T, of the temperature of the water supply_S－T_n1A second preset temperature, T, for the temperature of the water supply_S－T_n2For the second temperature after the temperature of the supplied water is reduced, T is more than 0_S－T_n3＜T_S－T_n2＜T_S－T_n1＜T_ST is at slave T_S－T_n1Down to T_S－T_n2During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.

when T ═ T is detected_S－T_n4When the electromagnetic valve is closed, the first electromagnetic valve or the second electromagnetic valve which is controlled to be closed is opened;

wherein T is the temperature of the supplied water, T_STo the maximum set temperature, T_S－T_n3A first preset temperature, T, of the temperature of the water supply_S－T_n4Is the first temperature after the temperature of the supplied water is reduced, T is more than 0_S－T_n4＜T_S－T_n3＜T_ST is at slave T_S－T_n3Down to T_S－T_n4During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.

Further, when T is detected_P≥T_PH－T_n1When the valve is opened, the liquid spraying valve is controlled to be opened;

when T is detected_P≤T_PH－T_n2When the valve is closed, the liquid spraying valve is controlled to be closed;

wherein, 0 < T_PH－T_n2＜T_PH－T_n1＜T_PH，T_PTo exhaust temperature, T_PHTo preset a maximum exhaust temperature, T_PH－T_n1Presetting the temperature, T, for the first exhaust_PH－T_n2For the second exhaust gasThe temperature is set.

The invention also 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:

when the water supply temperature is lower than a first preset temperature, all the electromagnetic valves are controlled to be kept open, and the liquid spraying valve is controlled to be kept closed;

when the water supply temperature is detected to reach a first preset temperature, controlling at least one electromagnetic valve to be closed;

when the exhaust temperature is detected to be greater than or equal to a first exhaust preset temperature, the liquid spraying valve is controlled to be opened, and when the exhaust temperature is detected to be less than or equal to a second exhaust preset temperature, the liquid spraying valve is controlled to be closed;

when the water supply temperature is detected to reach a second preset temperature, all the electromagnetic valves are controlled to be closed;

and 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, and when the external machine is restarted, all the electromagnetic valves are controlled to be opened.

Further, the control method includes the steps of:

Further, when it is detected that the water supply temperature reaches a first preset temperature, the step of controlling the at least one electromagnetic valve to close specifically includes:

when the water supply temperature is detected to reach a first preset temperature, controlling the first electromagnetic valve or the second electromagnetic valve to be closed;

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 electromagnetic valve or the second electromagnetic valve in the closed state is controlled to be closed for a first preset time and then opened;

and when the temperature of the supplied water is detected to be reduced, the heat output by the external machine is smaller than the heat absorbed by the load, and the first electromagnetic valve or the second electromagnetic valve in the closed state is controlled to be opened.

Further, when it is detected that the water supply temperature reaches a second preset temperature, the step of controlling all the electromagnetic valves to be closed specifically comprises:

when the water supply temperature is detected to reach a second preset temperature, the first electromagnetic valve and the second electromagnetic valve are controlled to be closed;

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 electromagnetic valve and/or the second electromagnetic valve are controlled to be opened after the first electromagnetic valve and the second electromagnetic valve are controlled to be closed for a second preset time;

and when the temperature of the supplied water is detected to be reduced, the heat output by the external machine is smaller than the heat absorbed by the load, and the first electromagnetic valve and/or the second electromagnetic valve are controlled to be opened.

The invention relates to an outdoor unit 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, wherein the throttling device comprises a main path throttling element and at least one branch path throttling element connected with the main path throttling element in parallel, the branch path throttling element is connected with an electromagnetic valve 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 outdoor unit control system also comprises a controller for connecting the electromagnetic valve and the liquid spraying valve, the flow and the temperature of the refrigerant entering the compressor are adjusted by controlling the opening and closing of the electromagnetic valve and the liquid spraying valve, and the output capacity of an outdoor unit is further adjusted to prolong the time, thereby reducing the frequency of the external unit to warm start and stop and ensuring the stability of water supply temperature.

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 a method for controlling a heat pump unit according to an embodiment of the present invention;

FIG. 4 is a flowchart illustrating another 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	154	First electromagnetic valve
11	Compressor with a compressor housing having a plurality of compressor blades	155	Second electromagnetic valve
				12	Liquid separator	20	Refrigerant circuit
13	Condenser	21	Liquid spraying pipeline
				15	Throttle device	211	Liquid spraying valve
151	A first throttling element	30	Heat exchange element
				152	First branch throttling element	40	Heating loop
153	Second branch throttling element

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 this embodiment, the outdoor unit control system includes a refrigerant circuit 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, where the throttling device 15 includes a main path throttling element 151 and at least one branch path throttling element connected in parallel with the main path throttling element 151, and the branch path throttling element is connected in series with a solenoid valve;

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 spray valve 211 and the electromagnetic valve, and controlling the liquid spray valve 211 and the electromagnetic valve to open and close, thereby adjusting the output capacity of the outdoor unit 10.

In this embodiment, the outdoor unit control system is mainly used for controlling the output of 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 refrigerant flow rate to adjust the change rate of the water supply 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.

In this embodiment, the throttling device 15 includes a main throttling element 151 and at least one branch throttling element connected in parallel with the main throttling element 151, the branch throttling element is connected in series with an electromagnetic valve, the refrigerant circuit 20 is connected in parallel with a liquid injection pipeline 21, the liquid injection pipeline 21 includes an inlet end and an outlet end, the inlet end is disposed on a pipeline between the heat exchange element 30 and the throttling device 15, the outlet end is disposed on a pipeline between the condenser 13 and the separator 12, the liquid injection pipeline 21 is provided with a liquid injection valve 211 for controlling the refrigerant to enter, so as to deliver the low-temperature liquid refrigerant after heat exchange between the heat exchange element 30 and the water to be heated in the heating circuit 40 to the refrigerant circuit 20 through the liquid injection pipeline 21, and neutralize the low-temperature liquid refrigerant with the gaseous refrigerant evaporated from the heat of the external environment in the condenser 13, so as to reduce the exhaust temperature in the external machine control system, and reducing the frequency of the shutdown of the external unit to the warm state.

Further, a controller is arranged in the control system of the external unit, the controller is connected with a liquid spraying valve 211 on a liquid spraying pipeline 21 and an electromagnetic valve in the throttling device 15, and the flow rate and the temperature of the refrigerant in the refrigerant loop 20 are adjusted by controlling the opening and closing of the electromagnetic valve and the liquid spraying valve 211, so that the change rate of the water supply temperature can be 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.

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 supplied water temperature reaches the highest set value continuously at least twice when the operation time is less than the preset 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.

With further reference to fig. 1, the throttling device 15 includes a first branch throttling element 152 and a second branch throttling element 153 connected in parallel with the main branch throttling element 151, a first solenoid valve 154 connected in series with the first branch throttling element 152, and a second solenoid valve 155 connected in series with the second branch throttling element 153, wherein the first solenoid valve 154 and the second solenoid valve 155 are connected to the controller (not shown).

In this embodiment, the throttling device 15 includes a first branch throttling element 152 and a second branch throttling element 153 connected in parallel with the main path throttling element 151, a first solenoid valve 154 in series with the first bypass restriction 152 and a second solenoid valve 155 in series with the second bypass restriction 153, the first and second electromagnetic valves 154 and 155 are connected to a controller of the external machine control system, the controller controls the opening and closing of the first and second solenoid valves 154 and 155, adjusts the amount of refrigerant introduced into the condenser 13, thereby controlling the quantity of the refrigerant for heat absorption and evaporation in the condenser 13, further adjusting the output quantity of the high-temperature and high-pressure gaseous refrigerant, ensuring the stability of the water temperature of the supplied water, in other embodiments, the throttling device 15 may further comprise more branch throttling elements in parallel with the main throttling element 151, solenoid valves in series with the branch throttling elements.

Further, referring to FIGS. 1 and 2, when T is detected to be [0, T_S－T_n3) During the interval, the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be kept open;

when T ═ T is detected_S－T_n3When the first electromagnetic valve 154 or the second electromagnetic valve 155 is closed, the first electromagnetic valve 154 or the second electromagnetic valve 155 is controlled to be closed;

when T ═ T is detected_S－T_n1At this time, the first solenoid valve 154 or the second solenoid valve 155 that controls the non-closed state is closed;

when T ═ T is detected_SWhen the engine is started, the outdoor unit 10 stops;

In this embodiment, the external unit 10 enters the control logic as shown in fig. 2 when being turned on, the detection module detects the water supply temperature T, and the water supply temperature T does not reach the first preset temperature T_S－T_n3Before, the controller controls the first electromagnetic valve 154 and the second electromagnetic valve 155 to be kept in the open state, so that the maximum refrigerant quantity in the refrigerant circuit 20 absorbs heat from the external environment in the condenser 13 and evaporates into a gaseous refrigerant, and after entering the compressor 11 for compression, the gaseous refrigerant outputting high temperature and high pressure and the water to be heated in the heating circuit 40 realize heat exchange in the heat exchange element 30, so that the water supply temperature rapidly reaches the first preset temperature T_S－T_n3At the water supply temperature T reaching T_S－T_n3In order to prolong the operation time of the outer unit 10, the first electromagnetic valve 154 or the second electromagnetic valve 155 is controlled to be closed to reduce the flow rate of the gaseous refrigerant entering the compressor 11, and further reduce the rising rate of the water supply temperature, in general, after the first electromagnetic valve 154 or the second electromagnetic valve 155 is controlled to be closed, the heat output by the outer unit 10 is still greater than the heat absorbed by the heating load, and the water supply temperature T continues to rise until the second preset temperature T is reached_S－T_n1At this time, in order to extend the operation time of the outdoor unit 10 again, the first electromagnetic valve 154 or the second electromagnetic valve 155 which is still in the open state is controlled to be closed, and if the heat output by the outdoor unit 10 is still greater than the heat absorbed by the heating load at this time, the water supply temperature T continues to rise along with the operation of the outdoor unit 10 until the maximum set temperature T is reached_SI.e. in (T)_S－T_n1，T_S) In the interval, the first solenoid valve 154 and the second solenoid valve 155 are controlled at all timesKeeping the closing state, and detecting that the water supply temperature T reaches the maximum set temperature T_SMeanwhile, the outer unit 10 is automatically stopped until the next logic cycle is started, and the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be opened. After the first solenoid valve 154 and/or the second solenoid valve 155 are/is closed, if the refrigerant in the refrigerant circuit 20 that is less in heat exchange absorbs a large amount of external heat, the exhaust temperature T is increased_PReaches a first preset exhaust temperature T_PH－T_n1To avoid reaching T due to exhaust gas temperature_PHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input to reduce the exhaust temperature, and the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is higher than the preset value, the liquid spraying valve 211 is controlled to be closed, and T is more than 0_S－T_n3＜T_S－T_n1＜T_ST is in [0, T_S]In the interval, the heat output by the external unit is larger than the heat absorbed by the load.

when T ═ T is detected_S－T_n31Meanwhile, the first electromagnetic valve 154 or the second electromagnetic valve 155 which controls the closed state is opened after being kept closed for a first preset time;

In this embodiment, the external unit 10 enters the control logic as shown in fig. 2 when being turned on, and the detection module detects the water supply temperature T, and when the water supply temperature T does not reach the first preset temperature T ═ T_S－T_n3Before, the controller controls the first electromagnetic valve 154 and the second electromagnetic valve 155 to be kept in the open state, so that the maximum refrigerant quantity in the refrigerant circuit 20 absorbs heat from the external environment in the condenser 13 and evaporates into a gaseous refrigerant, and after entering the compressor 11 for compression, the gaseous refrigerant outputting high temperature and high pressure and the water to be heated in the heating circuit 40 realize heat exchange in the heat exchange element 30, so that the water supply temperature quickly reaches the first preset temperature T ═ T_S－T_n3When the water supply temperature T reaches T ═ T_S－T_n3Meanwhile, in order to extend the operation time of the outer unit 10, the first solenoid valve 154 or the second solenoid valve 155 is controlled to be closed to reduce the flow rate of the gaseous refrigerant entering the compressor 11, thereby reducing the rising rate of the supply water temperature, and the supply water temperature T continues to rise until reaching the first saturation temperature T of the supply water temperature_S－T_n31When the heat output by the outdoor unit 10 is equal to the heat absorbed by the heating load, the water supply temperature T is not increased, and the water supply temperature T is detected to be T at T to ensure efficient operation of the outdoor unit 10_S－T_n31When the temperature of the water supply is not increased any more, the first electromagnetic valve 154 or the second electromagnetic valve 155, which is controlled to be closed, is kept closed for a first preset time and then opened, at this time, the heat output by the outer unit 10 is again greater than the heat absorbed by the heating load, and the water supply temperature T is continuously increased again until the maximum set temperature T is reached_SI.e. in (T)_S－T_n31，T_S) In the interval, the first solenoid valve 154 and the second solenoid valve 155 are both kept in the open state, and when the water supply temperature T is detected to reach the maximum set temperature T_SMeanwhile, the outer unit 10 is automatically stopped until the next logic cycle is started, and the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be opened. After the first solenoid valve 154 or the second solenoid valve 155 is controlled to be closed, if the exhaust temperature T in the refrigerant circuit 20 is lower than the predetermined temperature_PReaches a first preset exhaust temperature T_PH－T_n1To avoid reaching T due to exhaust gas temperature_PHCausing the outdoor unit 10 to stop and controlling the liquid discharge valve 211 to open so as to be lowered through the heat exchange member 30Inputting warm liquid refrigerant, reducing exhaust temperature, and detecting exhaust temperature T_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is higher than the preset value, the liquid spraying valve 211 is controlled to be closed, and T is more than 0_S－T_n3＜T_S－T_n31＜T_SWhen T is equal to T_S－T_n31When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.

In this embodiment, the external unit 10 enters the control logic as shown in fig. 2 when being turned on, and the detection module detects the water supply temperature T, and when the water supply temperature T does not reach the first preset temperature T ═ T_S－T_n3The first solenoid valve 154 and the second solenoid valve 155 are controlled by the controller to be kept open so as to maximize the refrigerant in the refrigerant circuit 20The heat absorbed from the external environment in the condenser 13 is evaporated into a gaseous refrigerant, and after entering the compressor 11 for compression, the gaseous refrigerant with high temperature and high pressure is output to exchange heat with the water to be heated in the heating loop 40 in the heat exchange element 30, so that the temperature of the supplied water rapidly reaches a first preset temperature T ═ T_S－T_n3When the water supply temperature T reaches T ═ T_S－T_n3Meanwhile, in order to extend the operation time of the outer unit 10, the first solenoid valve 154 or the second solenoid valve 155 is controlled to be closed to reduce the flow rate of the gaseous refrigerant entering the compressor 11, and further reduce the rising rate of the supply water temperature, and if the heat output by the outer unit 10 is greater than the heat absorbed by the heating load, the supply water temperature T will continue to rise until reaching the second preset temperature T_S－T_n1In order to extend the operation time of the outdoor unit 10, the first solenoid valve 154 or the second solenoid valve 155, which is controlled to be opened, is closed to further reduce the rising rate of the supply water temperature, and the supply water temperature T is raised to the second saturation temperature T of the supply water temperature_S－T_n11At this time, the heat output from the outdoor unit 10 is equal to the heat absorbed by the heating load, and the temperature of the supplied water is not increased any more, i.e., (T)_S－T_n1，T_S－T_n11) In the interval, the first and second electromagnetic valves 154 and 155 are controlled to be kept closed, and in order to ensure efficient operation of the outer unit 10, the water supply temperature T is detected to be T at T_S－T_n11When the temperature of the water supply water is not increased any more, after the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be closed for a second preset time, the first electromagnetic valve and/or the second electromagnetic valve are controlled to be opened, at this time, the heat output by the outer unit 10 is larger than the heat absorbed by the heating load again, and the water supply temperature T is continuously increased again until the maximum set temperature T is reached_SI.e. in (T)_S－T_n11，T_S) In the interval, the first solenoid valve 154 and/or the second solenoid valve 155 are/is kept in an open state, and when the water supply temperature T is detected to reach the maximum set temperature T_SMeanwhile, the outer unit 10 is automatically stopped until the next logic cycle is started, and the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be opened. After the first solenoid valve 154 and/or the second solenoid valve 155 are/is controlled to be closed, a large amount of external heat is absorbed by a small amount of refrigerant that undergoes heat exchange in the refrigerant circuit 20Heat and thus exhaust temperature T_PReaches a first preset exhaust temperature T_PH－T_n1To avoid reaching T due to exhaust gas temperature_PHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input to reduce the exhaust temperature, and the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is higher than the preset value, the liquid spraying valve 211 is controlled to be closed, and T is more than 0_S－T_n3＜T_S－T_n1＜T_S－T_n11＜T_SWhen T is equal to T_S－T_n1When the load is in use, the heat output by the external unit is equal to the heat absorbed by the load.

when T ═ T is detected_S－T_n1At this time, the first electromagnetic valve 154 or the second electromagnetic valve 155 that controls the open state is closed;

when T ═ T is detected_S－T_n2When the first electromagnetic valve 154 and/or the second electromagnetic valve 155 are/is controlled to be opened;

In this embodiment, when the outdoor unit 10 is turned on, the control logic shown in fig. 2 is entered,detect water supply temperature T by detection module, not reach first temperature T ═ T in water supply temperature T and predetermine temperature T ═ T_S－T_n3Before, the controller controls the first electromagnetic valve 154 and the second electromagnetic valve 155 to be kept in the open state, so that the maximum refrigerant quantity in the refrigerant circuit 20 absorbs external environment heat in the condenser 13 and is evaporated into a gaseous refrigerant, and after entering the compressor 11 for compression, the gaseous refrigerant outputting high temperature and high pressure and the water to be heated in the heating circuit 40 realize heat exchange in the heat exchange element 30, so that the water supply temperature quickly reaches the first preset temperature T ═ T_S－T_n3When the water supply temperature T reaches T ═ T_S－T_n3Meanwhile, in order to extend the operation time of the outdoor unit 10, the first solenoid valve 154 or the second solenoid valve 155 is controlled to be closed, and if the heat output by the outdoor unit 10 is greater than the heat absorbed by the heating load, the water supply temperature T will continue to rise along with the operation of the outdoor unit 10 until the water supply temperature T reaches the second preset temperature T_S－T_n1When, that is to say at (T)_S－T_n3，T_S－T_n1) In the interval, one of the first and second solenoid valves 154 and 155 is maintained in a closed state when the temperature of the supplied water reaches a second preset temperature T_S－T_n1Meanwhile, the first solenoid valve 154 or the second solenoid valve 155, which controls the open state, is closed, and if the heat output from the outer unit 10 is less than the heat absorbed by the heating load, that is, the first solenoid valve 154 and the second solenoid valve 155 are both closed, the temperature of the supplied water tends to decrease, that is, at (T)_S－T_n1，T_S－T_n2) In the interval, the first and second solenoid valves 154 and 155 are kept in a closed state, and in order to ensure the stability of the supply water temperature T, the supply water temperature T is detected to reach T_S－T_n2In this case, the first solenoid valve 154 or the second solenoid valve 155, which is controlled to be closed, is opened, and the heat output from the outer unit 10 is again larger than the heat absorbed by the heating load, so that the water temperature rises, and T ═ T is detected_S－T_n1Then, the first solenoid valve 154 or the second solenoid valve 155 for controlling the open state is closed, the first predetermined time is repeatedly performed, and then the open state of the first solenoid valve 154 and the second solenoid valve 155 is adjusted back, after which the water supply temperature T is continuously increased again until the maximum set temperature T is reached_SWhen the water supply temperature T is detected to reach the maximum set temperature T_SMeanwhile, the outer unit 10 is automatically stopped until the next logic cycle is started, and the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be opened. After the first solenoid valve 154 and/or the second solenoid valve 155 are/is closed, if the refrigerant in the refrigerant circuit 20 that is less in heat exchange absorbs a large amount of external heat, the exhaust temperature T is increased_PReaches a first preset exhaust temperature T_PH－T_n1To avoid reaching T due to exhaust gas temperature_PHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input to reduce the exhaust temperature, and the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is higher than the preset value, the liquid spraying valve 211 is controlled to be closed, and T is more than 0_S－T_n3＜T_S－T_n2＜T_S－T_n1＜T_ST is at slave T_S－T_n1Down to T_S－T_n2During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.

when T ═ T is detected_S－T_n4At this time, the first electromagnetic valve 154 or the second electromagnetic valve 155 that controls the closed state is opened;

In this embodiment, when the external unit 10 is turned on, the control logic shown in fig. 2 is entered, the detection module detects the water supply temperature T, and when the water supply temperature T does not reach the first preset temperature T ═ T_S－T_n3Before, the controller controls the first electromagnetic valve 154 and the second electromagnetic valve 155 to be kept in the open state, so that the maximum refrigerant quantity in the refrigerant circuit 30 absorbs external environment heat in the condenser 12 and evaporates into a gaseous refrigerant, and after entering the compressor 11 for compression, the gaseous refrigerant outputting high temperature and high pressure and the water to be heated in the heating circuit 40 realize heat exchange in the heat exchange element 30, so that the water supply temperature quickly reaches the first preset temperature T ═ T_S－T_n3When the water supply temperature T reaches T ═ T_S－T_n3Meanwhile, in order to extend the operation time of the outdoor unit 10, the first solenoid valve 154 or the second solenoid valve 155 is controlled to be closed, and if the heat output from the outdoor unit 10 is less than the heat absorbed by the heating load, that is, the first solenoid valve 154 or the second solenoid valve 155 is closed, the water supply temperature shows a downward trend (T) at which (T) the operation time is longer_S－T_n3，T_S－T_n4) In the interval, one of the first and second solenoid valves 154 and 155 is kept in a closed state, and in order to ensure the stability of the supply water temperature T, the supply water temperature T is detected to reach T_S－T_n4In this case, the first solenoid valve 154 or the second solenoid valve 155, which is controlled to be closed, is opened, and at this time, the heat output from the outer unit 10 is again greater than the heat absorbed by the heating load, the water supply temperature T is continuously increased again, and the water temperature T is increased to T ═ T_S－T_n3Then, the first electromagnetic valve 154 or the second electromagnetic valve 155 is controlled to close, the first electromagnetic valve 154 and the second electromagnetic valve 155 are adjusted back to the open state after the above-mentioned control is repeatedly performed for the second preset time, and then the outlet water temperature rises until the maximum set temperature T is reached_SWhen the water supply temperature T is detected to reach the maximum set temperature T_SIn time, the outer unit 10 is automatically stopped until the next logic cycle is started. After the first solenoid valve 154 or the second solenoid valve 155 is controlled to be closed, if the refrigerant in the refrigerant circuit 20 that is less in heat exchange absorbs a large amount of external heat, the exhaust temperature T is increased_PReaches a first preset exhaust temperature T_PH－T_n1When is, isAvoid the temperature of the exhaust gas from reaching T_PHThe outdoor unit 10 is stopped, the liquid injection valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input to reduce the exhaust temperature, and the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is higher than the preset value, the liquid spraying valve 211 is controlled to be closed, and T is more than 0_S－T_n4＜T_S－T_n3＜T_ST is at slave T_S－T_n3Down to T_S－T_n4During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.

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 main path throttling element 151, at least one branch path throttling element connected in parallel with the main path throttling element 151, the branch path throttling element is connected in series with an electromagnetic valve, the refrigerant loop 20 is connected in parallel with a liquid spraying pipeline 21, an inlet end of the liquid spraying pipeline 21 is disposed between the heat exchange element 30 and the throttling device 15, an outlet end of the liquid spraying pipeline 21 is disposed between the condenser 13 and the separator 12, the liquid spraying pipeline 21 is provided with a liquid spraying valve 211 for controlling a flow rate of the pipeline, the external unit control system further includes a controller for connecting the electromagnetic valve and the liquid spraying valve 211, and by controlling opening and closing of the electromagnetic valve and the liquid spraying, the flow rate and temperature of the refrigerant entering the compressor 11 are adjusted, and the output capacity of the outdoor unit 10 is adjusted to prolong the time that the water supply temperature reaches the maximum set temperature, so that the frequency of the outdoor unit 10 starting and stopping at a temperature 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: when the water supply temperature is lower than a first preset temperature, all the electromagnetic valves are controlled to be kept open, and the liquid spraying valve is controlled to be kept closed;

s12: when the water supply temperature is detected to reach a first preset temperature, controlling at least one electromagnetic valve to be closed;

s13: when the exhaust temperature is detected to be greater than or equal to a first exhaust preset temperature, the liquid spraying valve is controlled to be opened, and when the exhaust temperature is detected to be less than or equal to a second exhaust preset temperature, the liquid spraying valve is controlled to be closed;

s14: when the water supply temperature is detected to reach a second preset temperature, all the electromagnetic valves are controlled to be closed;

s15: and 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, and when the external machine is restarted, all the electromagnetic valves are controlled to be opened.

In this embodiment, referring to fig. 1 to 2, when the heat pump unit operates to realize heating, in order to reduce the frequent start and stop of the external unit 10 of the heat pump unit during operation to a certain extent, which causes the fluctuation of the temperature of the supplied water to be large, when detecting that the operation time of the external unit 10 is less than the preset value at least twice continuously, so that the temperature of the supplied water reaches the maximum set temperature and the external unit stops operating, referring to the following control logic, before the temperature of the supplied water reaches the first preset temperature, the electromagnetic valves are all kept open, and the liquid injection valve 211 is closed, so that the maximum refrigerant quantity in the refrigerant loop 20 absorbs the heat of the external environment in the condenser 13, evaporates and is compressed by the compressor 11, and then can output high-temperature and high-pressure gaseous refrigerant, so that the water to be heated in the heating loop 40 can exchange heat with high-temperature and high-pressure gaseous refrigerant in the heat exchange element, the water supply temperature reaches the preset first water supply temperature, primary heating is realized, in order to prolong the running time of the outdoor unit 10 and delay the speed of the water supply temperature reaching the maximum set temperature, the water supply temperature is detected to reach the maximum set temperatureWhen the first preset temperature is reached, at least one electromagnetic valve is controlled to be closed, the flow of the refrigerant entering the compressor 11 is reduced, if a small amount of refrigerant participating in heat exchange in the refrigerant loop 20 absorbs a large amount of external heat at the moment, and then the exhaust temperature reaches the first exhaust preset temperature, in order to avoid stopping the outer unit 10 due to the fact that the exhaust temperature reaches the preset maximum exhaust temperature, the liquid spraying valve 211 is controlled to be opened, low-temperature liquid refrigerant passing through the heat exchange element 30 is input to reduce the exhaust temperature, and when the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is high, the liquid discharge valve 211 is controlled to be closed. After controlling at least one electromagnetic valve to be closed, if the heat output by the outdoor unit 10 is greater than the heat absorbed by the heating load, the water supply temperature will continue to rise along with the operation of the outdoor unit 10, in order to further prolong the operation time of the outdoor unit 10 and prolong the time when the water supply temperature reaches the maximum set temperature, when the water supply temperature reaches a second preset temperature, all the electromagnetic valves are controlled to be closed, the flow of the refrigerant passing through the condenser 13 is minimum, if the refrigerant in the refrigerant loop 20 that is less in heat exchange absorbs a large amount of external heat, and the exhaust temperature reaches a first preset exhaust temperature, in order to avoid the stop of the outdoor unit 10 caused by the exhaust temperature reaching the maximum preset exhaust temperature, the liquid spraying valve 211 is controlled to be opened, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input, so as to reduce the exhaust temperature_PReducing to a second preset exhaust temperature T_PH－T_n2When the electromagnetic valve is fully closed, if the output heat of the outdoor unit is greater than the heat absorbed by a heating load, the water supply temperature can continue to rise, when the water supply temperature reaches the maximum set temperature, the outdoor unit 10 is automatically stopped, when the outdoor unit 10 is detected to be restarted, all the electromagnetic valves are controlled to be opened, and the next control logic cycle is entered.

Referring to fig. 4, fig. 4 is a flowchart of another embodiment of the control method of the heat pump unit of the present invention.

In this embodiment, with further reference to fig. 1-2, when the heat pump unit is operating to provide heating, in order to reduce the frequent start and stop of the outdoor unit 10 of the heat pump unit in the running process to a certain extent, which causes the great fluctuation of the water temperature of the water supply, when the water supply temperature reaches the maximum set temperature and stops when the operation time of the outdoor unit 10 is less than the preset value for at least two consecutive times in the continuous operation process, the following control logic is referred to for operation, before the water supply temperature reaches the first preset temperature, the control solenoid valves are all kept open, and the liquid spraying valve 211 is controlled to be closed, so that the maximum refrigerant quantity in the refrigerant circuit 20 absorbs the heat of the external environment in the condenser 13 and is evaporated into a gaseous refrigerant with a higher temperature, so that the refrigerant gas is compressed by the compressor 11 and then outputs high-temperature and high-pressure gaseous refrigerant, so that the water to be heated in the heating circuit 40 can exchange heat with the high-temperature and high-pressure gaseous refrigerant in the heat exchange element 30 in the shortest time.When the water supply temperature reaches the first preset temperature, controlling at least one electromagnetic valve to close to reduce the flow of the refrigerant entering the compressor 11, after controlling the at least one electromagnetic valve to close, if the heat output by the outdoor unit 10 is greater than the heat absorbed by the heating load, the water supply temperature will continue to rise along with the operation of the outdoor unit 10, in order to further prolong the operation time of the outdoor unit 10, and prolong the time when the water supply temperature reaches the maximum preset temperature, when detecting that the water supply temperature reaches the second preset temperature, controlling all the electromagnetic valves to close, at this moment, the flow of the refrigerant passing through the condenser 13 is minimum, and if at this moment, when the exhaust temperature reaches the first exhaust preset temperature due to the fact that less refrigerant participating in heat exchange in the refrigerant loop 20 absorbs a large amount of external heat, in order to avoid the shutdown of the external unit 10 caused by the exhaust temperature reaching the preset maximum exhaust temperature, the liquid injection valve 211 is controlled to be opened to input the low-temperature liquid refrigerant passing through the heat exchange element 30 to reduce the exhaust temperature, and the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the water supply temperature reaches the maximum set temperature, the outer unit 10 is automatically stopped, and when the outer unit 10 is detected to be restarted, all the electromagnetic valves are controlled to be opened to enter the next control logic cycle.

Further, throttling arrangement includes first solenoid valve and second solenoid valve, when detecting supply water temperature reaches first preset temperature, the step of controlling at least one solenoid valve to close specifically includes:

In the present embodiment, referring to fig. 1, the throttling device 15 includes a first electromagnetic valve 154 and a second electromagnetic valve 155, and when the water supply temperature is detected to reach a first preset temperature, the first electromagnetic valve 154 or the second electromagnetic valve 155 is controlled to be closed; if a small amount of refrigerant participating in heat exchange in the refrigerant circuit 20 absorbs a large amount of external heat and the exhaust temperature reaches the first preset exhaust temperature, in order to avoid the shutdown of the external unit 10 due to the exhaust temperature reaching the preset maximum exhaust temperature, the liquid spraying valve 211 is controlled to open, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input, and the exhaust temperature is reduced when the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is high, the liquid spraying valve 211 is controlled to be closed; when the water supply temperature is detected not to rise any more, the output heat of the outdoor unit 10 is equal to the heat absorbed by the heating load, and in order to ensure the efficient operation of the outdoor unit 10, the first electromagnetic valve 154 or the second electromagnetic valve 155 which is in the closed state is controlled to be closed for a first preset time and then opened, so that the outdoor unit 10 is stopped when the water supply temperature reaches the highest set temperature, and the normal start and stop of the outdoor unit 10 are ensured; if the first electromagnetic valve 154 or the second electromagnetic valve 155 is closed, the output heat of the external unit 10 is smaller than the heat absorbed by the heating load, the water supply temperature will exhibit a downward trend, when the water supply temperature is detected to decrease, the first electromagnetic valve 154 or the second electromagnetic valve 155 in the closed state is controlled to open, when the water temperature rises to a first preset temperature, the first electromagnetic valve 154 or the second electromagnetic valve 155 is controlled to close, the first preset time is repeatedly executed, the first electromagnetic valve 154 and the second electromagnetic valve 155 are turned back to the open state, and then the water outlet temperature rises to a stop state, so as to ensure that the water supply temperature is kept within a preset temperature range.

Further, throttling arrangement includes first solenoid valve and second solenoid valve, when detecting supply water temperature reaches the second and predetermines the temperature, the step of controlling all solenoid valves to close specifically includes:

In the present embodiment, referring to fig. 1, the throttling device 15 includes a first electromagnetic valve 154 and a second electromagnetic valve 155, and when the water supply temperature is detected to reach a second preset temperature, the first electromagnetic valve 154 and the second electromagnetic valve 155 are controlled to be closed; if a small amount of refrigerant participating in heat exchange in the refrigerant circuit 20 absorbs a large amount of external heat and the exhaust temperature reaches the first preset exhaust temperature, in order to avoid the shutdown of the external unit 10 due to the exhaust temperature reaching the preset maximum exhaust temperature, the liquid spraying valve 211 is controlled to open, so that the low-temperature liquid refrigerant passing through the heat exchange element 30 is input to reduce the exhaust temperature, and when the exhaust temperature T is detected_PReducing to a second preset exhaust temperature T_PH－T_n2When the pressure is high, the liquid spraying valve 211 is controlled to be closed; when the water supply temperature is detected not to rise any more, the output heat of the outdoor unit 10 is equal to the heat absorbed by the heating load, and in order to ensure efficient operation of the outdoor unit 10, after the first electromagnetic valve 154 and the second electromagnetic valve 155 are kept closed for a second preset time, the second electromagnetic valve 154 and/or the second electromagnetic valve 155 are controlled to be opened, so that the outdoor unit 10 is stopped when the water supply temperature reaches the maximum set temperature, and normal start and stop of the outdoor unit 10 are ensured; if the output heat of the outer unit 10 is less than the heat absorbed by the heating load after the first and second electromagnetic valves 154 and 155 are closed, the water supply temperature may be decreased, and when the decrease in the water supply temperature is detected, the first and second electromagnetic valves 154 and 155 that are closed are controlled to be closedThe water temperature is partially opened, when the water temperature rises to reach a second preset temperature, the first electromagnetic valve 154 or the second electromagnetic valve 155 which controls the opening state is closed, the opening state of the first electromagnetic valve 154 and the opening state of the second electromagnetic valve 155 are adjusted back after the control is repeatedly executed for the second preset time, and the water temperature rises to be stopped so as to ensure that the water supply temperature is kept within a 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

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 main path throttling element and at least one branch path throttling element connected with the main path throttling element in parallel, and the branch path throttling element is connected with an electromagnetic valve in series;

the controller is connected with the liquid spraying valve and the electromagnetic valve, controls the liquid spraying valve and the electromagnetic valve to be opened and closed, and adjusts the output capacity of the external unit;

the control system of the external unit also comprises a detection module, and the controller is started when the external unit is detected to be stopped when the running time of the external unit is less than a preset value and the water supply temperature reaches the highest set temperature for at least two times.

2. The outdoor unit control system according to claim 1, wherein the throttling means includes a first branch throttling element, a second branch throttling element connected in parallel with the main path throttling element, a first solenoid valve connected in series with the first branch throttling element, and a second solenoid valve connected in series with the second branch throttling element, the first solenoid valve and the second solenoid valve being connected to the controller.

3. The outdoor unit control system according to claim 2,

when T is detected to be [0, T_S－T_n3) During interval, controlling the first electromagnetic valve and the second electromagnetic valve to be kept open;

4. The outdoor unit control system according to claim 2,

5. The outdoor unit control system according to claim 2,

6. The outdoor unit control system according to claim 2,

when examiningMeasuring T at [0, T_S－T_n3) During interval, controlling the first electromagnetic valve and the second electromagnetic valve to be kept open;

7. The outdoor unit control system according to claim 2,

wherein T is the temperature of the supplied water, T_STo the maximum set temperature, T_S－T_n3Is a first preset temperature of the water supply temperatureDegree, T_S－T_n4Is the first temperature after the temperature of the supplied water is reduced, T is more than 0_S－T_n4＜T_S－T_n3＜T_ST is at slave T_S－T_n3Down to T_S－T_n4During the period, the heat output by the outer machine is smaller than the heat absorbed by the load.

8. The outdoor unit control system according to any one of claims 1 to 7,

when T is detected_P≥T_PH－T_n1When the valve is opened, the liquid spraying valve is controlled to be opened;

wherein, 0 < T_PH－T_n2＜T_PH－T_n1＜T_PH，T_PTo exhaust temperature, T_PHTo preset a maximum exhaust temperature, T_PH－T_n1Presetting the temperature, T, for the first exhaust_PH－T_n2A preset temperature for the second exhaust.

9. A heat pump unit comprising the external unit control system according to claim 8.

10. A control method for a heat pump unit according to claim 9, characterized in that the control method comprises the steps of:

11. The heat pump unit control method according to claim 10, wherein the step of controlling at least one electromagnetic valve to close when the supply water temperature is detected to reach a first preset temperature specifically comprises:

12. The heat pump unit control method according to claim 10, wherein the step of controlling all the electromagnetic valves to be closed when the supply water temperature is detected to reach a second preset temperature specifically comprises: