CN118347165A - Start control method and system of hot gas bypass system - Google Patents

Abstract

The embodiment of the invention discloses a method and a system for controlling the starting of a hot gas bypass system. The hot gas bypass system comprises a refrigeration module, a waterway module and a controller, wherein the refrigeration module comprises a compressor, a heat exchanger, a liquid storage tank and at least two throttle valves, an inlet and an outlet of the compressor are communicated through pipelines where the throttle valves are located, the inlet and the outlet of the compressor are communicated through pipelines where the heat exchanger and the liquid storage tank are located, the pipelines where the heat exchanger and the liquid storage tank are located are provided with at least one throttle valve, the waterway module comprises a water pump, the heat exchanger is communicated with the water pump, the compressor, the throttle valves and the water pump are all electrically connected with the controller, and the starting control method comprises the following steps: receiving a control instruction; and controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction so as to realize the quick start of the hot gas bypass system. The starting control method and the starting control system for the hot gas bypass system can ensure the rapid starting of the system.

Description

Start control method and system of hot gas bypass system

Technical Field

The embodiment of the invention relates to a hot gas bypass control technology, in particular to a starting control method and a starting control system of a hot gas bypass system.

Background

And the heat exchange of the hot gas bypass system, such as a heat pump system applied to the new energy automobile, is performed for the new energy automobile. At present, the starting control method of the existing hot gas bypass system has the problem that the high pressure of the system cannot be quickly lifted, so that the heating requirement of a passenger cabin or a battery of an automobile can be met only after a long time is needed, and after the hot gas bypass system is started and high-low pressure difference is established, the heat exchange power of the high pressure and the heat exchanger of the system is difficult to stably maintain, so that the high pressure and the low pressure of the system are greatly fluctuated, and further, the air outlet temperature of the passenger cabin and the water inlet and outlet temperature of the battery are greatly changed, and the control reliability is affected.

Disclosure of Invention

The embodiment of the invention provides a starting control method and a starting control system for a hot gas bypass system, which are used for ensuring the quick starting of the system.

In a first aspect, an embodiment of the present invention provides a start control method of a hot gas bypass system, where the hot gas bypass system includes a refrigeration module, a waterway module and a controller, the refrigeration module includes a compressor, a heat exchanger, a liquid storage tank and at least two throttles, an inlet and an outlet of the compressor are communicated through a pipeline where the throttles are located, the inlet and the outlet of the compressor are communicated through a pipeline where the heat exchanger and the liquid storage tank are located, at least one throttle is provided in a pipeline where the heat exchanger and the liquid storage tank are located, the waterway module includes a water pump, the heat exchanger is communicated with the water pump, and the compressor, the throttle and the water pump are all electrically connected with the controller, and the start control method includes:

receiving a control instruction;

And controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction so as to realize the rapid start of the hot gas bypass system.

Optionally, the heat exchanger comprises a first heat exchanger and a second heat exchanger, the throttle valve comprises a first throttle valve and a second throttle valve, and the waterway module comprises a first water pump and a second water pump; the inlet and the outlet of the compressor are communicated through a pipeline where the first throttle valve is located, the outlet of the compressor is communicated with the inlet of the compressor through the first heat exchanger, the liquid storage tank, the second throttle valve and the second heat exchanger in sequence, one end of the first water pump is communicated with the first heat exchanger, the other end of the first water pump is communicated with the first heat exchanger through corresponding loads, one end of the second water pump is communicated with the second heat exchanger, and the other end of the second water pump is communicated with the second heat exchanger through corresponding loads;

and controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction, wherein the working states comprise:

When the control command is a start control command, controlling the compressor and the second water pump to be started at respective target rotating speeds, enabling each throttle valve to work, enabling the first water pump to be closed, and adjusting the working state of the system when the control time reaches a preset first time; wherein the opening degree of the first throttle valve is larger than the opening degree of the second throttle valve.

Optionally, when the control time reaches a preset first time, adjusting the working state of the system includes:

When the control time reaches the preset first time, the rotating speed of the compressor and the starting rotating speed of the first water pump are controlled according to the system pressure, the opening of the second throttle valve is controlled according to the superheat degree of the inlet of the compressor, the opening of the first throttle valve is controlled to be reduced, the second water pump runs at the target rotating speed of the second water pump, and when the control time reaches the preset second time, the working state of the system is adjusted.

Optionally, when the control time reaches a preset second time, adjusting the working state of the system includes:

When the control time reaches a preset second time, the rotation speeds of the compressor and the first water pump and the opening of the first throttle valve are controlled according to the system pressure, the opening of the second throttle valve is controlled according to the superheat degree of the inlet of the compressor, and the second water pump is controlled to operate at the target rotation speed.

Optionally, the refrigeration module further comprises a gas-liquid separator, the heat exchanger comprises a condenser, a cooler and a third heat exchanger, the throttle valve comprises a third throttle valve and a fourth throttle valve, and the waterway module comprises a third water pump, a fourth water pump and a multi-way valve assembly; the inlet and the outlet of the compressor are communicated through a pipeline where the third throttle valve is located, the outlet of the compressor is communicated with the inlet of the gas-liquid separator through the condenser, the liquid storage tank, the third heat exchanger, the fourth throttle valve and the cooler in sequence, the outlet of the gas-liquid separator is communicated with the third heat exchanger, the third heat exchanger is communicated with the inlet of the compressor, the third water pump is communicated with the condenser, the fourth water pump is communicated with the cooler, the third water pump and the fourth water pump are communicated with the multi-way valve assembly, and the multi-way valve assembly is communicated with a load;

and controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction, wherein the working states comprise:

When the control command is a start control command, the compressor and the fourth water pump are controlled to be started at respective target rotating speeds, the opening degree of the third throttle valve and the opening rotating speed of the third water pump are controlled according to the system pressure, the opening degree of the fourth throttle valve is controlled according to the inlet superheat degree of the compressor, and when the control time reaches a preset third time, the working state of the system is adjusted.

Optionally, when the control time reaches a preset third time, adjusting the working state of the system includes:

When the control time reaches a preset third time, controlling the rotation speeds of the compressor and the third water pump according to the system pressure, controlling the opening of the fourth throttle valve according to the inlet superheat degree of the compressor, controlling the opening of the third throttle valve to be reduced, controlling the fourth water pump to run at the target rotation speed of the fourth water pump, and adjusting the working state of the system when the control time reaches the preset fourth time;

When the control time reaches a preset fourth time, the rotating speed of the compressor and the rotating speed of the third water pump are controlled according to the system pressure, the opening of the third throttle valve is controlled according to the system pressure, the opening of the fourth throttle valve is controlled according to the inlet superheat degree of the compressor, and the fourth water pump is controlled to operate at the target rotating speed.

In a second aspect, embodiments of the present invention provide a hot gas bypass system comprising: the refrigerating module comprises a compressor, a heat exchanger, a liquid storage tank and at least two throttle valves, wherein an inlet and an outlet of the compressor are communicated through a pipeline where the throttle valves are located, the inlet and the outlet of the compressor are communicated through the heat exchanger and the pipeline where the liquid storage tank is located, the heat exchanger and the pipeline where the liquid storage tank is located are provided with at least one throttle valve, the water path module comprises a water pump, the heat exchanger is communicated with the water pump, and the compressor, the throttle valves and the water pump are all electrically connected with the controller.

Optionally, the heat exchanger comprises a first heat exchanger and a second heat exchanger, the throttle valve comprises a first throttle valve and a second throttle valve, and the waterway module comprises a first water pump and a second water pump; the inlet and the outlet of the compressor are communicated through a pipeline where the first throttle valve is located, the outlet of the compressor is sequentially communicated with the first heat exchanger, the liquid storage tank, the second throttle valve and the second heat exchanger, one end of the first water pump is communicated with the first heat exchanger, the other end of the first water pump is communicated with the first heat exchanger through corresponding loads, one end of the second water pump is communicated with the second heat exchanger, and the other end of the second water pump is communicated with the second heat exchanger through corresponding loads.

Optionally, the refrigeration module further comprises a gas-liquid separator, the heat exchanger comprises a third heat exchanger, a fourth heat exchanger and a fifth heat exchanger, the throttle valve comprises a third throttle valve and a fourth throttle valve, and the waterway module comprises a third water pump, a fourth water pump and a multi-way valve assembly; the inlet and the outlet of the compressor are communicated through a pipeline where the third throttle valve is located, the outlet of the compressor is communicated with the inlet of the gas-liquid separator through the third heat exchanger, the liquid storage tank, the fourth heat exchanger, the fourth throttle valve and the fifth heat exchanger in sequence, the outlet of the gas-liquid separator is communicated with the fourth heat exchanger, the fourth heat exchanger is communicated with the inlet of the compressor, the third water pump is communicated with the third heat exchanger, the fourth water pump is communicated with the fifth heat exchanger, the third water pump and the fourth water pump are communicated with the multi-way valve assembly, and the multi-way valve assembly is communicated with a load.

Optionally, both the inlet and the outlet of the compressor are provided with pressure and temperature sensors.

The embodiment of the invention provides a starting control method and a system of a hot gas bypass system, wherein the hot gas bypass system comprises a refrigeration module, a waterway module and a controller, the refrigeration module comprises a compressor, a heat exchanger, a liquid storage tank and at least two throttle valves, an inlet and an outlet of the compressor are communicated through pipelines where one throttle valve is positioned, the inlet and the outlet of the compressor are communicated through pipelines where the heat exchanger and the liquid storage tank are positioned, the pipelines where the heat exchanger and the liquid storage tank are positioned are provided with at least one throttle valve, the waterway module comprises a water pump, the heat exchanger is communicated with the water pump, and the compressor, the throttle valves and the water pump are electrically connected with the controller: receiving a control instruction; and controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction so as to realize the quick start of the hot gas bypass system. According to the starting control method and system for the hot gas bypass system, provided by the embodiment of the invention, the working states of the compressor, the throttle valve and the water pump are controlled according to the control instruction, so that the hot gas bypass system can be started quickly, for example, the compressor is controlled to be started at a target rotating speed, and the rotating speed of the compressor is controlled according to the system pressure after the compressor is started for a preset time; the working state of controlling the water pump when controlling the compressor to start comprises the rotation speed of the water pump, and simultaneously controlling the opening of each throttle valve, for example, according to the superheat degree of the inlet of the compressor and the opening of each throttle valve regulated by the pressure of the system, the high pressure of the system can be rapidly increased, the high-low pressure difference can be rapidly established, the heat exchange requirement of the system is met, the system can reasonably distribute the flow of the refrigerant in a smooth mode after establishing the high-low pressure state of the system, and the system enters steady-state control under the condition of not causing obvious fluctuation of the water inlet and outlet temperature of the load, thereby ensuring the control reliability.

Drawings

FIG. 1 is a flow chart of a method for controlling the start-up of a hot gas bypass system according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method for controlling the start-up of a hot gas bypass system according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a hot gas bypass system according to a second embodiment of the present invention;

Fig. 4 is a schematic diagram of a throttle opening and a system pressure change according to a second embodiment of the present invention;

FIG. 5 is a flow chart of a method for controlling the start-up of a hot gas bypass system according to a third embodiment of the present invention;

FIG. 6 is a schematic illustration of a hot gas bypass system provided in accordance with a third embodiment of the present invention;

FIG. 7 is a schematic illustration of a hot gas bypass system in a first stage according to a third embodiment of the present invention;

FIG. 8 is a schematic diagram of a hot gas bypass system in a second stage and a third stage according to a third embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

Example 1

Fig. 1 is a flowchart of a start control method of a hot gas bypass system according to an embodiment of the present invention, where the embodiment is applicable to aspects such as start control of the hot gas bypass system, and the hot gas bypass system includes a refrigeration module, a water path module, and a controller, where the refrigeration module includes a compressor, a heat exchanger, a liquid storage tank, and at least two throttles, an inlet and an outlet of the compressor are connected through a pipeline where the throttles are located, the inlet and the outlet of the compressor are connected through a pipeline where the heat exchanger and the liquid storage tank are located, the pipeline where the heat exchanger and the liquid storage tank are located is provided with at least one throttle, the water path module includes a water pump, the heat exchanger is connected with the water pump, and the compressor, the throttle and the water pump are all electrically connected with the controller, and the method can be performed by the controller in the hot gas bypass system, and the controller can be implemented in software and/or hardware, and the method specifically includes the following steps:

step 110, receiving a control instruction.

The control command may be a start control command of the system, and the control command may be externally input to the controller. The inlet and the outlet of the compressor can be provided with pressure temperature sensors, the pressure temperature sensors can acquire pressure data and temperature data, and the controller is electrically connected with each pressure temperature sensor in the system so as to acquire real-time data of each pressure temperature sensor.

And 120, controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction so as to realize the quick start of the hot gas bypass system.

Specifically, when the control command is an opening control command, the working states of the compressor, the throttle valve and the water pump are controlled, for example, the compressor is controlled to start at a target rotation speed, and the rotation speed of the compressor is controlled according to the system pressure after a preset time, for example, 1min after the start. The working state of controlling the water pump while controlling the compressor to start comprises the rotation speed of the water pump, and simultaneously controlling the opening of each throttle valve, for example, controlling the opening of the throttle valve communicating the outlet and the inlet of the compressor to be maximum, wherein the opening of the other throttle valve can be adjusted according to the superheat degree of the inlet of the compressor, and the opening of the throttle valve communicating the outlet and the inlet of the compressor is reduced after the preset working time of 1min, the opening of the throttle valve is reduced to the target opening within a certain time period, and then the opening of the throttle valve is adjusted according to the system pressure, so that the system can be started quickly.

It should be noted that the specific duration of the preset time may be determined according to the actual control requirement, which is not limited herein.

According to the start control method of the hot gas bypass system, the working states of the compressor, the throttle valve and the water pump are controlled according to the control instruction, so that the hot gas bypass system can be started quickly, for example, the compressor is controlled to be started at a target rotating speed, and the rotating speed of the compressor is controlled according to the system pressure after the compressor is started for a preset time; the working state of controlling the water pump when controlling the compressor to start comprises the rotation speed of the water pump, and simultaneously controlling the opening of each throttle valve, for example, according to the superheat degree of the inlet of the compressor and the opening of each throttle valve regulated by the pressure of the system, the high pressure of the system can be rapidly increased, the high-low pressure difference can be rapidly established, the heat exchange requirement of the system is met, the system can reasonably distribute the flow of the refrigerant in a smooth mode after establishing the high-low pressure state of the system, and the system enters steady-state control under the condition of not causing obvious fluctuation of the water inlet and outlet temperature of the load, thereby ensuring the control reliability.

Example two

Fig. 2 is a flowchart of a startup control method of a hot gas bypass system provided by a second embodiment of the present invention, where the embodiment is applicable to aspects such as startup control of the hot gas bypass system, and the hot gas bypass system includes a refrigeration module, a waterway module and a controller, the refrigeration module includes a compressor, a heat exchanger, a liquid storage tank and at least two throttles, an inlet and an outlet of the compressor are communicated through a pipeline where the throttle valve is located, the inlet and the outlet of the compressor are communicated through a pipeline where the heat exchanger and the liquid storage tank are located, the pipeline where the heat exchanger and the liquid storage tank are located is provided with at least one throttle valve, the waterway module includes a water pump, the heat exchanger is communicated with the water pump, the compressor, the throttle valve and the water pump are all electrically connected with the controller, and the method can be performed by the controller in the hot gas bypass system, and the controller can be implemented in software and/or hardware, and the method specifically includes the following steps:

step 210, receiving a control instruction.

The control command may be a start control command of the system, and the control command may be externally input to the controller. The inlet and the outlet of the compressor can be provided with pressure temperature sensors, the pressure temperature sensors can acquire pressure data and temperature data, and the controller is electrically connected with each pressure temperature sensor in the system so as to acquire real-time data of each pressure temperature sensor.

Fig. 3 is a schematic diagram of a hot gas bypass system according to a second embodiment of the present invention. Referring to fig. 3, the hot gas bypass system may be applied to an electric vehicle, the refrigeration module includes a compressor 10, a heat exchanger 20, a liquid storage tank 30 and at least two throttles 40, an inlet and an outlet of the compressor 10 are communicated through a pipeline where the throttles 40 are located, an inlet and an outlet of the compressor 10 are communicated through a pipeline where the heat exchanger 20 and the liquid storage tank 30 are located, at least one throttles 40 are provided in a pipeline where the heat exchanger 20 and the liquid storage tank 30 are located, the waterway module includes a water pump 50, the heat exchanger 20 is communicated with the water pump 50, and the compressor 10, the throttles 40 and the water pump 50 are all electrically connected with a controller (not shown in the figure). Wherein the heat exchanger 20 comprises a first heat exchanger 21 and a second heat exchanger 22, the throttle valve 40 comprises a first throttle valve 41 and a second throttle valve 41, and the waterway module comprises a first water pump 51 and a second water pump 52; the first throttle valve 41 is a hot gas bypass valve, the inlet and the outlet of the compressor 10 are communicated through a pipeline where the first throttle valve 41 is located, the outlet of the compressor 10 is communicated with the inlet of the compressor 10 through the first heat exchanger 21, the liquid storage tank 30, the second throttle valve 42 and the second heat exchanger 22 in sequence, one end of the first water pump 51 is communicated with the first heat exchanger 21, the other end of the first water pump 51 is communicated with the first heat exchanger 21 through a corresponding load, one end of the second water pump 52 is communicated with the second heat exchanger 22, and the other end of the second water pump 52 is communicated with the second heat exchanger 22 through a corresponding load.

Specifically, the load that first water pump 51 communicates includes the air conditioning case, the air conditioning case includes water-cooled heat exchanger 61 and evaporimeter 62, evaporimeter 62 is kept away from water-cooled heat exchanger 61 one side and is provided with air-blower 63, be provided with temperature sensor T1 in the pipeline of load intercommunication first heat exchanger 21, the load that second water pump 52 communicates includes another water-cooled heat exchanger 64, water-cooled heat exchanger 64 one side is provided with air suction fan 65, be provided with another temperature sensor T2 in the pipeline of load intercommunication second heat exchanger 22, the export and the entry of compressor all are provided with pressure temperature sensor PT. The refrigerant flowing out of the outlet of the compressor 10 exchanges heat through the first heat exchanger 21 (the heat of the refrigerant is transferred to the waterway, the passenger compartment or the battery of the electric vehicle is heated through the first water pump 51, the water-cooled heat exchanger 61 and the water temperature sensor T1), then the refrigerant passes through the liquid storage tank 3 and then passes through the first throttle valve 4 to be throttled and expanded to be a refrigerant in a low-temperature low-pressure state, the refrigerant in the low-temperature low-pressure state passes through the second heat exchanger 22 (the refrigerant absorbs air or the heat of the electric drive circuit is returned to the refrigerant through the second water pump 52, the water-cooled heat exchanger 64 and the water temperature sensor T2), and finally enters the inlet of the compressor 10 to start the next heat exchange cycle. The hot gas bypass circuit, namely the circuit in which the first throttle valve 41 is positioned, is connected in parallel with the circuit in which the heat exchange circuit, namely the two heat exchangers are positioned, and the high-temperature refrigerant directly returns to the inlet of the compressor 10 through the first throttle valve 41, is mixed with the refrigerant in the heat exchange circuit and then directly enters the compressor 10 to start the next bypass cycle. The circuit where the load connected to the first water pump 51 is located is a load circuit that needs to be heated, such as a passenger cabin heating circuit or a battery pack heating circuit (not shown in the figure) of the electric vehicle. The circuit where the load connected by the second water pump 52 is located is a load circuit providing a heat source, such as an air heat source and an electric driving heat source (not shown), and the selection of different heat sources is realized through different waterway structures.

Step 220, when the control command is a start control command, controlling the compressor and the second water pump to be started at respective target rotating speeds, enabling each throttle valve to work, enabling the first water pump to be closed, and adjusting the working state of the system when the control time reaches a preset first time; wherein the opening degree of the first throttle valve is larger than the opening degree of the second throttle valve.

Fig. 4 is a schematic diagram illustrating a throttle opening and a system pressure change according to a second embodiment of the present invention. Referring to fig. 4, curves L1 to L5 are an opening curve of the second throttle valve, an opening curve of the first throttle valve, an actual rotation speed curve of the compressor, an actual high pressure curve, and an actual low pressure curve, respectively, and a preset first time is 1min, and for a first stage, that is, a stage in which the compressor is started to a preset first time, for rapidly increasing the system high pressure and the refrigerant circulation speed, a target high pressure of the compressor may be set to 22Bar (calibration value 1), and the maximum increase rotation speed per second is 1000 rotations (calibration value 2). The calibration value 1 is set for rapidly increasing the rotation speed of the compressor, the target rotation speed is as high as 1000r/s, the corresponding pressure is usually set to be more than 20bar, and the corresponding saturation temperature is 67 ℃, so that the heating requirements of the passenger cabin and the battery can be rapidly met. The rotational speed of the compressor climbs and is related to the compressor itself, the supply voltage, the ambient temperature and the different refrigerants and oil content factors, since the first stage requires the system high pressure to be lifted as soon as possible, the calibration value 2 is set by climbing at the maximum rotational speed of the compressor. The controller is according to the entry degree of superheat of compressor, if the degree of superheat of entry is kept at 7 degrees (calibration value 3), controls the aperture of second choke valve, and the great promotion that can influence refrigerant flow of compressor entry degree of superheat, undersize then has the risk of compressor suction liquid-carrying, in order to avoid the compressor suction liquid-carrying condition to appear, the entry degree of superheat of compressor needs to set up at 5 to 7 degrees. The controller controls the opening of the first throttle valve to be 100% of the maximum opening (calibration value 4), the calibration value 4 determines the starting time of the hot gas bypass system, the opening of the throttle valve is large, the flow rate of the refrigerant is large, the work-doing speed of the compressor is fast to lift, the high pressure is fast to lift, but the high pressure overshoot regulation of the system is easy to cause, the high pressure of the compressor is too high to protect and stop, and therefore the calibration value 4 needs to slowly lift the calibration opening according to the maturity of the overall parameters of the system. The ambient temperature of the loop where the second water pump is located is 5 degrees higher than the water temperature (calibration value 5), and the second water pump is started 50 percent, namely the starting rotating speed is 50 percent of the rated rotating speed (calibration value 6). The calibration value of 5 may represent the endothermic effect of an ambient heat source, the greater the calibration value, the more likely the load will absorb heat from the environment. The more heat is absorbed from the environment, the easier it is to raise the system low pressure and thus the system high pressure. Therefore, under the condition of meeting the heat absorption condition, the time for lifting the system by the system to high pressure can be further shortened by absorbing effective heat as much as possible. The heat exchange efficiency of the environmental heat source is determined by the opening degree of the water pump, and the calibration value 6 is not required to be too small in order to improve the heat exchange efficiency of the heat exchanger. The first water pump is turned off and the load such as a blower can be controlled normally. Because the first stage is a system heat storage stage, the first water pump needs to be turned off to quickly raise the high pressure of the system.

And 230, when the control time reaches the preset first time, controlling the rotating speed of the compressor and the starting rotating speed of the first water pump according to the system pressure, controlling the opening of the second throttle valve according to the superheat degree of the inlet of the compressor, controlling the opening of the first throttle valve to be reduced, controlling the second water pump to operate at the target rotating speed of the second water pump, and when the control time reaches the preset second time, adjusting the working state of the system.

Specifically, referring to fig. 4, the preset second time is 10min, and for the second stage, that is, the stage from the preset first time to the preset second time, the battery or the passenger compartment starts to absorb heat, the circulation speed of the refrigerant and the high pressure of the system are maintained, and after the rotation speed of the compressor is increased, the rotation speed is closed-loop controlled according to the difference between the target pressure and the actual high pressure of the system. The opening degree of the first throttle valve is adjusted according to the inlet superheat degree of the compressor so that the inlet superheat degree of the compressor is 7 degrees (a calibration value 3), and when the actual high pressure exceeds the calibration value (a calibration value 12), the first stage is ended and the second stage control is performed. The opening degree of the first regulating valve is reduced to a calibration position (calibration value 8) in a unit time (calibration value 7). In order to avoid the first stage high voltage overshoot, it is necessary to exit the first stage start-up control after the actual high voltage reaches the calibrated value 12. The calibration value 12 varies somewhat from ambient temperature to ambient temperature, typically to a maximum of not more than 20bar. Since the refrigerant flow in the system is very large at high rotation speed of the compressor, the small change of the first throttle valve has a great influence on the refrigerant flow, so that the adjustment speed of the first throttle valve needs to be controlled, and obvious fluctuation of high and low pressures of the system is avoided. Because the second throttle valve continuously controls the superheat degree of the system, the opening degree of the second throttle valve has no definite directivity, and in order to distribute heat to the heat exchanger loop, the opening degree of the first throttle valve needs to be controlled to be reduced so as to avoid the oscillation phenomenon of the first throttle valve and the second throttle valve in the control process. The ambient temperature of the loop where the second water pump is located is 5 degrees higher than the water temperature (calibration value 5), and the second water pump is opened by 50 percent (calibration value 6). After the high pressure exceeds 20bar (calibration value 9), the first water pump is started to calibrate the opening degree according to the actual high pressure (calibration value 10). When the system compressor works at the maximum capacity, the heat exchange treatment of the passenger cabin or the battery loop needs to be started as soon as possible, the high pressure is limited to break through the upper protection limit, and the heating requirement of the thermal system is met. Typically, the upper limit of the high-pressure protection is around 25bar, and the calibration value 9 does not exceed 20bar. The opening speed of the first water pump determines the heat exchange efficiency of the first heat exchanger, the water temperature is low in the initial stage, the heat exchange efficiency is high, the upper limit of the opening of the first water pump needs to be slowly lifted according to the actual high pressure, and the high pressure oscillation of the system is avoided.

And 240, when the control time reaches a preset second time, controlling the rotating speeds of the compressor and the first water pump and the opening of the first throttle valve according to the system pressure, controlling the opening of the second throttle valve according to the superheat degree of the inlet of the compressor, and controlling the second water pump to operate at the target rotating speed.

Specifically, as shown in fig. 4, for the third stage, i.e. the stage after the preset second time, the transient control of the hot gas bypass is excessive to the steady-state control, and after the rotation speed of the compressor is increased, the closed-loop control of the rotation speed is performed according to the difference between the target pressure and the actual high pressure of the system. The high pressure of the system may be the compressor outlet pressure and the low pressure of the system may be the compressor inlet pressure. The degree of superheat at the inlet of the compressor is made 7 degrees (calibration value 3) by adjusting the opening degree of the second throttle valve. The system target low pressure is made to be in the range of 2-5Bar (calibration value 11) by adjusting the opening degree of the first throttle valve. The opening of the first throttle valve in the third stage needs to be reduced to a certain range, a target low pressure calibration value 11 is determined according to the system target pressure, and when the system target pressure is higher, the control target value of the target low pressure is properly reduced, so that the flow of the refrigerant is reduced within the system capacity range, and the high pressure control requirement of the system is met; when the target pressure of the system is lower, the target low pressure value of the system can be properly increased, and the power generation capacity of the compressor can be improved as much as possible. The first water pump is started to calibrate the opening degree (calibration value 10) according to the actual high pressure, the second water pump is positioned in a loop, the ambient temperature is 5 degrees higher than the water temperature (calibration value 5), and the second water pump is started by 50 percent (calibration value 6).

It should be noted that, in this embodiment, specific duration of each preset time, and specific size of the parameter corresponding to each calibration value may be determined according to actual control requirements, which is not limited herein.

According to the start control method of the hot gas bypass system, the compressor is controlled to start at the target rotating speed according to the control instruction, and the rotating speed of the compressor is controlled according to the system pressure after the compressor is started for a preset time; the working state of controlling the water pump when controlling the compressor to start comprises the rotation speed of the water pump, and simultaneously controlling the opening of each throttle valve, including adjusting the opening of each throttle valve according to the superheat degree of the inlet of the compressor and the pressure of the system, the system can be rapidly started and rapidly lifted by the high pressure of the system, the high-low pressure difference is rapidly established, the heat exchange requirement of the system is met, the system can reasonably distribute the flow of the refrigerant in a smooth mode after establishing the high-low pressure state of the system, and the system enters steady-state control under the condition of not causing obvious fluctuation of the water inlet and outlet temperature of the load, thereby ensuring the control reliability.

Example III

Fig. 5 is a flowchart of a startup control method of a hot gas bypass system provided by a third embodiment of the present invention, where the embodiment is applicable to aspects such as startup control of the hot gas bypass system, and the hot gas bypass system includes a refrigeration module, a waterway module and a controller, the refrigeration module includes a compressor, a heat exchanger, a liquid storage tank and at least two throttles, an inlet and an outlet of the compressor are communicated through a pipeline where the throttle valve is located, the inlet and the outlet of the compressor are communicated through a pipeline where the heat exchanger and the liquid storage tank are located, the pipeline where the heat exchanger and the liquid storage tank are located is provided with at least one throttle valve, the waterway module includes a water pump, the heat exchanger is communicated with the water pump, the compressor, the throttle valve and the water pump are all electrically connected with the controller, and the method can be performed by the controller in the hot gas bypass system, and the controller can be implemented in software and/or hardware, and the method specifically includes the following steps:

Step 310, receiving a control instruction.

The control command may be a start control command of the system, and the control command may be externally input to the controller. The inlet and the outlet of the compressor can be provided with pressure temperature sensors, the pressure temperature sensors can acquire pressure data and temperature data, and the controller is electrically connected with each pressure temperature sensor in the system so as to acquire real-time data of each pressure temperature sensor.

Illustratively, FIG. 6 is a schematic diagram of a hot gas bypass system provided in accordance with a third embodiment of the present invention. Referring to fig. 6, the refrigeration module further includes a gas-liquid separator 70, the heat exchanger 20 includes a third heat exchanger 23, a condenser 24, and a cooler 25, the throttle valve 40 includes a third throttle valve 43 and a fourth throttle valve 44, and the waterway module includes a third water pump 53, a fourth water pump 54, and a multi-way valve assembly 80; the inlet and the outlet of the compressor 10 are communicated through a pipeline where the third throttle valve 43 is located, the outlet of the compressor 10 is communicated with the inlet of the air-liquid separator 70 through the condenser 24, the liquid storage tank 30, the third heat exchanger 23, the fourth throttle valve 44 and the cooler 25 in sequence, the outlet of the air-liquid separator 70 is communicated with the third heat exchanger 23, the third heat exchanger 23 is communicated with the inlet of the compressor 10, the third water pump 53 is communicated with the condenser 24, the fourth water pump 54 is communicated with the cooler 25, the third water pump 53 and the fourth water pump 54 are communicated with the multi-way valve assembly 80, the multi-way valve assembly 80 is communicated with a load, and the load comprises a battery pack assembly 91 and a warm air core 92. Specifically, in the hot gas bypass heating mode, the low-temperature low-pressure refrigerant becomes high-temperature high-pressure refrigerant after being worked by the compressor, and then is divided into two paths, the main path releases heat to the cooling liquid side in the condenser 24, and the multi-way valve assembly 80 is used for conveying the heat to the battery pack assembly 91 and the warm air core 92, so that the purposes of battery heating and cabin heating are achieved. The auxiliary passage is throttled by the third throttle valve 43 and then is sucked by the compressor 10 after merging with the low-temperature refrigerant from the coaxial tube heat exchanger, i.e., the third heat exchanger 23 (if the apparatus is selected). The refrigerant flowing out of the condenser 24 flows through the liquid storage tank 30 (if a liquid storage tank is selected, a gas-liquid separator is not arranged), then enters the coaxial pipe heat exchanger (if the equipment is selected) for heat exchange, enters the cooler 25 for absorbing the heat of the cooling liquid side after being throttled by the fourth throttle valve 44, and flows through the gas-liquid separator 70 (if the liquid storage tank is selected, the liquid storage tank is not arranged) to be sucked again by the compressor 10. The coolant on the water path side of the cooler 25 flows through the fourth water pump 54, the multi-way valve assembly 80 and the low temperature radiator 93 in this order, absorbs heat from the ambient air by the cooling fan 94, flows through the motor assembly 95 and the high pressure water heater 96 (which may be optionally turned on or off) as supplemental heat sources, and finally flows back to the cooler 25 for the next cycle.

And 320, when the control command is a start control command, controlling the compressor and the fourth water pump to be started at respective target rotating speeds, controlling the opening degree of the third throttle valve and the opening rotating speed of the third water pump according to the system pressure, controlling the opening degree of the fourth throttle valve according to the inlet superheat degree of the compressor, and adjusting the working state of the system when the control time reaches a preset third time.

Illustratively, FIG. 7 is a schematic illustration of a hot gas bypass system in a first stage provided in accordance with a third embodiment of the present invention. And the first stage of hot gas bypass, namely the stage of starting the compressor until the control time reaches the preset third time, rapidly increasing the system high pressure and the refrigerant circulation speed, performing rotating speed closed-loop control according to the difference value between the system target pressure and the actual high pressure after the rotating speed is increased by the compressor, controlling the opening degree of a fourth throttle valve to enable the inlet superheat degree of the compressor to be 7 degrees (calibration value 3), and after the actual high pressure of the system exceeds the calibration value 12, ending the first stage and entering the second stage of control. And (3) reducing the actual opening of the third throttle valve to a calibration position (calibration value 8) in unit time (calibration value 7), starting the calibration opening of the third water pump according to the actual high pressure after the high pressure exceeds 20bar (calibration value 9), starting the air source heat absorption circuit of the fourth water pump at an ambient temperature 5 degrees higher than the water temperature (calibration value 5) and starting the fourth water pump at 50 percent (calibration value 6).

And 330, controlling the rotation speeds of the compressor and the third water pump according to the system pressure when the control time reaches the preset third time, controlling the opening of the fourth throttle valve according to the inlet superheat degree of the compressor, controlling the opening of the third throttle valve to be reduced, controlling the fourth water pump to run at the target rotation speed of the fourth water pump, and adjusting the working state of the system when the control time reaches the preset fourth time.

Illustratively, FIG. 8 is a schematic diagram of a hot gas bypass system in a second stage and a third stage according to a third embodiment of the present invention. The second stage of hot gas bypass, namely the stage of controlling time from the preset third time to the preset fourth time, the battery or the passenger cabin starts to absorb heat, the circulation speed of the refrigerant and the high pressure of the system are maintained, after the rotation speed of the compressor is increased, the rotation speed is controlled in a closed loop mode according to the difference value between the target pressure and the actual high pressure of the system, the opening degree of the fourth throttle valve is controlled to enable the superheat degree of the inlet of the compressor to be 7 degrees (a calibration value of 3), and when the actual high pressure of the system exceeds the calibration value of 12, the first stage is ended, and the second stage of control is carried out. And (3) reducing the actual opening of the third throttle valve to a calibration position (calibration value 8) in unit time (calibration value 7), starting the calibration opening of the third water pump according to the actual high pressure after the high pressure exceeds 20bar (calibration value 9), starting the air source heat absorption circuit of the fourth water pump at an ambient temperature 5 degrees higher than the water temperature (calibration value 5) and starting the fourth water pump at 50 percent (calibration value 6).

And 340, when the control time reaches a preset fourth time, controlling the rotating speed of the compressor and the rotating speed of the third water pump according to the system pressure, controlling the opening of the third throttle valve according to the system pressure, controlling the opening of the fourth throttle valve according to the inlet superheat degree of the compressor, and controlling the fourth water pump to operate at the target rotating speed.

Specifically, in the third stage of hot gas bypass, namely, the stage after the control time reaches the preset fourth time, the transient control of hot gas bypass is excessive to the steady-state control, after the rotating speed of the compressor is increased, the rotating speed is controlled in a closed loop mode according to the difference value between the target pressure and the actual high pressure of the system, the opening degree of the fourth throttle valve is controlled to enable the superheat degree of the inlet of the compressor to be 7 degrees (a calibration value 3), and meanwhile, the opening degree of the third throttle valve is controlled to enable the target low pressure of the system to be in a range of 2-5Bar (a calibration value 11). After the high pressure exceeds 20bar (calibration value 9), the third water pump is started to calibrate the opening degree according to the actual high pressure (calibration value 10), the air source heat absorption loop where the fourth water pump is positioned is higher than the water temperature by 5 degrees (calibration value 5), and the fourth water pump is started by 50 percent (calibration value 6).

It should be noted that, in this embodiment, the specific duration of each preset time may be determined according to the actual control requirement, which is not limited herein.

According to the start control method of the hot gas bypass system, the compressor is controlled to start at the target rotating speed according to the control instruction, and the rotating speed of the compressor is controlled according to the system pressure after the compressor is started for a preset time; the working state of controlling the water pump when controlling the compressor to start comprises the rotation speed of the water pump, and simultaneously controlling the opening of each throttle valve, including adjusting the opening of each throttle valve according to the superheat degree of the inlet of the compressor and the pressure of the system, the system can be rapidly started and rapidly lifted by the high pressure of the system, the high-low pressure difference is rapidly established, the heat exchange requirement of the system is met, the system can reasonably distribute the flow of the refrigerant in a smooth mode after establishing the high-low pressure state of the system, and the system enters steady-state control under the condition of not causing obvious fluctuation of the water inlet and outlet temperature of the load, thereby ensuring the control reliability.

Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements, combinations, and substitutions can be made by those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.

Claims (10)

1. The utility model provides a start control method of hot gas bypass system, its characterized in that, hot gas bypass system includes refrigeration module, water route module and controller, refrigeration module includes compressor, heat exchanger, liquid storage pot and two at least choke valves, the entry and the export of compressor are through a choke valve place pipeline intercommunication, the compressor entry and the export are through heat exchanger with liquid storage pot place pipeline intercommunication, heat exchanger with liquid storage pot place pipeline is provided with at least one choke valve, the water route module includes the water pump, the heat exchanger with the water pump intercommunication, the compressor, choke valve and the water pump all with the controller electricity is connected, start control method includes:

receiving a control instruction;

And controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction so as to realize the rapid start of the hot gas bypass system.

2. The start-up control method of claim 1, wherein the heat exchanger comprises a first heat exchanger and a second heat exchanger, the throttle valve comprises a first throttle valve and a second throttle valve, and the waterway module comprises a first water pump and a second water pump; the inlet and the outlet of the compressor are communicated through a pipeline where the first throttle valve is located, the outlet of the compressor is communicated with the inlet of the compressor through the first heat exchanger, the liquid storage tank, the second throttle valve and the second heat exchanger in sequence, one end of the first water pump is communicated with the first heat exchanger, the other end of the first water pump is communicated with the first heat exchanger through corresponding loads, one end of the second water pump is communicated with the second heat exchanger, and the other end of the second water pump is communicated with the second heat exchanger through corresponding loads;

and controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction, wherein the working states comprise:

When the control command is a start control command, controlling the compressor and the second water pump to be started at respective target rotating speeds, enabling each throttle valve to work, enabling the first water pump to be closed, and adjusting the working state of the system when the control time reaches a preset first time; wherein the opening degree of the first throttle valve is larger than the opening degree of the second throttle valve.

3. The method for controlling start-up according to claim 2, wherein adjusting the operating state of the system when the control time reaches a preset first time comprises:

When the control time reaches the preset first time, the rotating speed of the compressor and the starting rotating speed of the first water pump are controlled according to the system pressure, the opening of the second throttle valve is controlled according to the superheat degree of the inlet of the compressor, the opening of the first throttle valve is controlled to be reduced, the second water pump runs at the target rotating speed of the second water pump, and when the control time reaches the preset second time, the working state of the system is adjusted.

4. The start-up control method according to claim 3, wherein adjusting the operating state of the system when the control time reaches a preset second time includes:

When the control time reaches a preset second time, the rotation speeds of the compressor and the first water pump and the opening of the first throttle valve are controlled according to the system pressure, the opening of the second throttle valve is controlled according to the superheat degree of the inlet of the compressor, and the second water pump is controlled to operate at the target rotation speed.

5. The start-up control method of claim 1, wherein the refrigeration module further comprises a gas-liquid separator, the heat exchanger comprises a condenser, a cooler, and a third heat exchanger, the throttle valve comprises a third throttle valve and a fourth throttle valve, and the waterway module comprises a third water pump, a fourth water pump, and a multi-way valve assembly; the inlet and the outlet of the compressor are communicated through a pipeline where the third throttle valve is located, the outlet of the compressor is communicated with the inlet of the gas-liquid separator through the condenser, the liquid storage tank, the third heat exchanger, the fourth throttle valve and the cooler in sequence, the outlet of the gas-liquid separator is communicated with the third heat exchanger, the third heat exchanger is communicated with the inlet of the compressor, the third water pump is communicated with the condenser, the fourth water pump is communicated with the cooler, the third water pump and the fourth water pump are communicated with the multi-way valve assembly, and the multi-way valve assembly is communicated with a load;

and controlling the working states of the compressor, the throttle valve and the water pump according to the control instruction, wherein the working states comprise:

When the control command is a start control command, the compressor and the fourth water pump are controlled to be started at respective target rotating speeds, the opening degree of the third throttle valve and the opening rotating speed of the third water pump are controlled according to the system pressure, the opening degree of the fourth throttle valve is controlled according to the inlet superheat degree of the compressor, and when the control time reaches a preset third time, the working state of the system is adjusted.

6. The method for controlling start-up according to claim 5, wherein adjusting the operating state of the system when the control time reaches a preset third time includes:

When the control time reaches a preset third time, controlling the rotation speeds of the compressor and the third water pump according to the system pressure, controlling the opening of the fourth throttle valve according to the inlet superheat degree of the compressor, controlling the opening of the third throttle valve to be reduced, controlling the fourth water pump to run at the target rotation speed of the fourth water pump, and adjusting the working state of the system when the control time reaches the preset fourth time;

When the control time reaches a preset fourth time, the rotating speed of the compressor and the rotating speed of the third water pump are controlled according to the system pressure, the opening of the third throttle valve is controlled according to the system pressure, the opening of the fourth throttle valve is controlled according to the inlet superheat degree of the compressor, and the fourth water pump is controlled to operate at the target rotating speed.

7. A hot gas bypass system, comprising: the refrigerating module comprises a compressor, a heat exchanger, a liquid storage tank and at least two throttle valves, wherein an inlet and an outlet of the compressor are communicated through a pipeline where the throttle valves are located, the inlet and the outlet of the compressor are communicated through the heat exchanger and the pipeline where the liquid storage tank is located, the heat exchanger and the pipeline where the liquid storage tank is located are provided with at least one throttle valve, the water path module comprises a water pump, the heat exchanger is communicated with the water pump, and the compressor, the throttle valves and the water pump are all electrically connected with the controller.

8. The hot gas bypass system of claim 7, wherein the heat exchanger comprises a first heat exchanger and a second heat exchanger, the throttle valve comprises a first throttle valve and a second throttle valve, and the waterway module comprises a first water pump and a second water pump; the inlet and the outlet of the compressor are communicated through a pipeline where the first throttle valve is located, the outlet of the compressor is sequentially communicated with the first heat exchanger, the liquid storage tank, the second throttle valve and the second heat exchanger, one end of the first water pump is communicated with the first heat exchanger, the other end of the first water pump is communicated with the first heat exchanger through corresponding loads, one end of the second water pump is communicated with the second heat exchanger, and the other end of the second water pump is communicated with the second heat exchanger through corresponding loads.

9. The hot gas bypass system of claim 7, wherein the refrigeration module further comprises a gas-liquid separator, the heat exchangers including a third heat exchanger, a fourth heat exchanger, and a fifth heat exchanger, the throttle valve including a third throttle valve and a fourth throttle valve, the water circuit module including a third water pump, a fourth water pump, and a multi-way valve assembly; the inlet and the outlet of the compressor are communicated through a pipeline where the third throttle valve is located, the outlet of the compressor is communicated with the inlet of the gas-liquid separator through the third heat exchanger, the liquid storage tank, the fourth heat exchanger, the fourth throttle valve and the fifth heat exchanger in sequence, the outlet of the gas-liquid separator is communicated with the fourth heat exchanger, the fourth heat exchanger is communicated with the inlet of the compressor, the third water pump is communicated with the third heat exchanger, the fourth water pump is communicated with the fifth heat exchanger, the third water pump and the fourth water pump are communicated with the multi-way valve assembly, and the multi-way valve assembly is communicated with a load.

10. The hot gas bypass system of claim 7, wherein both the inlet and outlet of the compressor are provided with pressure temperature sensors.