Air conditioner refrigeration and heating automatic control system and method based on parallel condensation

Abstract

The invention discloses an air conditioner refrigeration and heating automatic control system and method based on parallel condensation. The refrigerant loop enables the compressor, the outdoor condenser and fan assembly, the heating ventilation air conditioner and the heat exchanger to be selectively communicated or not communicated through pipelines and valves to form an air conditioner air outlet temperature adjusting loop for preventing the temperature of an air conditioner air outlet from being too high or too low. The air conditioner air outlet temperature adjusting loop comprises a first adjusting branch loop and a second adjusting branch loop. The first adjusting branch loop comprises a compressor, an indoor condenser and a heating assembly of the heating ventilation air conditioner and an evaporator of the heating ventilation air conditioner which are connected in series through a pipeline and a valve; the second adjusting branch loop comprises a compressor, an outdoor condenser, a fan assembly, a heat exchanger and an evaporator which are connected in series through pipelines and valves. The first adjusting branch loop and the second adjusting branch loop are simultaneously opened to prevent the temperature of the air outlet of the air conditioner from being too high; the temperature of the air outlet of the air conditioner can be prevented from being too low by opening the first adjusting branch loop and closing the second adjusting branch loop.

Description

Technical Field

[0001] This invention relates to the field of thermal management system technology for new energy vehicles, specifically to an automatic control system and method for air conditioning cooling and heating based on parallel condensation. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the thermal management system of pure electric vehicles has undergone technological upgrades and optimizations. Direct cooling and direct heating thermal management systems have been widely used due to their significant potential for cost reduction and efficiency improvement. The core design intention of this system is to reduce the overall vehicle manufacturing cost and energy consumption by simplifying the system structure and eliminating the heating air circuit and battery water circuit in traditional thermal management systems, thus meeting the core requirements of pure electric vehicles for economy and range.

[0003] However, direct-cooling and direct-heating thermal management systems have revealed significant comfort deficiencies in practical applications, becoming a key issue restricting user experience. Specifically, traditional thermal management systems are equipped with a warm air circuit, which can achieve precise control of the outlet air temperature through the accurate adjustment of the mixed hot and cold air dampers to match user needs under different operating conditions; while direct-cooling and direct-heating systems adopt a direct heat pump architecture, and the adjustment of its hot and cold air dampers is strictly limited: improper adjustment can easily trigger the system's high-pressure protection mechanism, leading to degraded system operation or even direct shutdown, seriously affecting system stability.

[0004] The aforementioned structural characteristics and adjustment limitations make the system highly susceptible to temperature control inaccuracies under low-load conditions: in cooling mode, even when the cooling system's output capacity has been reduced to its minimum design value, the outlet air temperature remains consistently cold, failing to meet users' needs for gentle cooling; in heating mode, when the heating system's capacity is at its minimum output, the outlet air temperature remains high, causing discomfort for passengers. This lack of temperature control precision has generated numerous user complaints and has become a critical technical challenge that directly cooling and heating thermal management systems urgently need to address. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide an automatic control system and method for air conditioning cooling and heating based on parallel condensation that can meet the temperature control accuracy requirements of direct cooling and heating thermal management systems and will not cause degraded operation or shutdown due to high-pressure protection of the system.

[0006] To achieve this objective, the present invention designs an automatic air conditioning cooling and heating control system based on parallel condensation, comprising a refrigerant circuit and a coolant circuit. The refrigerant circuit includes a compressor, an outdoor condenser and fan assembly, a heating, ventilation, and air conditioning (HVAC) system, and a heat exchanger that exchanges heat with the coolant circuit. The refrigerant circuit can selectively connect or disconnect the compressor, the outdoor condenser and fan assembly, the HVAC system, and the heat exchanger through pipes and valves to form an air outlet temperature regulation circuit to prevent the air outlet temperature from being too high or too low. The air outlet temperature regulation circuit includes a first regulation sub-circuit and a second regulation sub-circuit. The first regulation sub-circuit includes the compressor, the indoor condenser and heating assembly of the HVAC system, and the evaporator of the HVAC system connected in series through pipes and valves. The second regulation sub-circuit includes the compressor, the outdoor condenser and fan assembly, the heat exchanger, and the evaporator connected in series through pipes and valves. Simultaneous activation of the first and second regulation sub-circuit can prevent the air outlet temperature from being too high. Activation of the first regulation sub-circuit and deactivation of the second regulation sub-circuit can prevent the air outlet temperature from being too low.

[0007] Furthermore, a first electronic expansion valve is installed on the pipe connected to the refrigerant inlet of the evaporator, and a second electronic expansion valve is installed on the pipe connected to the refrigerant outlet of the indoor condenser and heating assembly.

[0008] Furthermore, a first solenoid valve is installed on the pipeline connected to the refrigerant inlet of the outdoor condenser and fan assembly.

[0009] Furthermore, this invention also designs an automatic control method for air conditioning cooling and heating based on the above-described automatic control system for air conditioning cooling and heating based on parallel condensing, including an automatic control method for air conditioning outlet temperature that is too low and an automatic control method for air conditioning outlet temperature that is too high; the automatic control method for air conditioning outlet temperature that is too low includes: determining whether the air conditioning outlet temperature is too low; if the air conditioning outlet temperature is too low, then opening the first regulating sub-loop, closing the second regulating sub-loop, and adjusting the refrigerant flow rate entering the evaporator through the indoor condenser and heating component to increase the air conditioning outlet temperature; the automatic control method for air conditioning outlet temperature that is too high includes: determining whether the air conditioning outlet temperature is too high; if the air conditioning outlet temperature is too high, then simultaneously opening the first regulating sub-loop and the second regulating sub-loop, and adjusting the refrigerant flow rate passing through the indoor condenser and heating component to decrease the air conditioning outlet temperature.

[0010] Furthermore, the automatic control method for adjusting the air outlet temperature to be too low also includes: obtaining the actual evaporation temperature T4, setting the target evaporation temperature T2, and adjusting the refrigerant flow rate entering the evaporator after passing through the indoor condenser and heating components, so that the actual evaporation temperature T4 rises to the target evaporation temperature T2.

[0011] Furthermore, the automatic control method for excessively high outlet temperature also includes: obtaining the actual evaporation temperature T4, setting the target evaporation temperature T2, and adjusting the refrigerant flow rate through the indoor condenser and heating components to reduce the actual evaporation temperature T4 to the target evaporation temperature T2.

[0012] Furthermore, the method for determining whether the air conditioner outlet temperature is too low includes: obtaining the actual air outlet temperature T3 of the air conditioner outlet, setting a low temperature threshold TL and a duration TIME1 for the air conditioner outlet, and if T3≤TL and the duration reaches TIME1, then the air conditioner outlet temperature is too low; the method for determining whether the air conditioner outlet temperature is too high includes: obtaining the actual air outlet temperature T3 of the air conditioner outlet, setting a high temperature threshold TH and a duration TIME2 for the air conditioner outlet, and if T3≥TH and the duration reaches TIME2, then the air conditioner outlet temperature is too high.

[0013] Furthermore, the method of adjusting the refrigerant flow rate entering the evaporator through the indoor condenser and heating assembly to increase the air conditioner outlet temperature includes: setting a target air outlet temperature T1, calculating the difference between the target air outlet temperature T1 and the actual air outlet temperature T3, and reducing the refrigerant flow rate entering the evaporator through the indoor condenser and heating assembly according to an incremental PID control algorithm, so that the actual air outlet temperature T3 increases to the target air outlet temperature T1; the method of adjusting the refrigerant flow rate entering the evaporator through the indoor condenser and heating assembly to decrease the air conditioner outlet temperature includes: setting a target air outlet temperature T1, calculating the difference between the target air outlet temperature T1 and the actual air outlet temperature T3, and reducing the refrigerant flow rate through the indoor condenser and heating assembly according to an incremental PID control algorithm, so that the actual air outlet temperature T3 decreases to the target air outlet temperature T1.

[0014] Furthermore, the method for adjusting the refrigerant flow rate entering the evaporator through the indoor condenser and heating assembly includes: calculating the difference between the target evaporation temperature T2 and the actual evaporation temperature T4, and reducing the refrigerant flow rate entering the evaporator through the indoor condenser and heating assembly according to an incremental PID control algorithm.

[0015] Furthermore, the method for adjusting the refrigerant flow rate through the indoor condenser and heating assembly includes: calculating the difference between the target evaporation temperature T2 and the actual evaporation temperature T4, and reducing the refrigerant flow rate through the indoor condenser and heating assembly according to an incremental PID control algorithm.

[0016] The beneficial effects of this invention are:

[0017] Improved user comfort: This feature addresses the issue of excessively high or low air outlet temperatures caused by surplus heating or cooling capacity when the compressor speed is at its lowest, thus resolving user complaints about temperature comfort. For example, it prevents users from feeling too cold when cooling demand is low, and prevents users from feeling too hot when heating demand is low.

[0018] Optimizing compressor energy consumption: By using parallel condenser, the system high pressure is reduced, thus decreasing the compressor's suction and discharge pressure ratio. Since a higher pressure ratio results in higher energy consumption, the system designed in this invention optimizes compressor energy consumption, which can improve the overall vehicle range for electric vehicles, etc.

[0019] Reduced system shutdown risk: This solution addresses the issue of excessively high compressor pressure caused by excessively high low pressure when the air conditioner is turned on for heating in ambient temperatures, such as 20°C. This indirectly reduces the risk of the compressor shutting down due to excessively high pressure, thus avoiding user complaints.

[0020] Preventing evaporator frost: This solves the risk of evaporator frost when the air conditioner is turned on for cooling in low-temperature and high-humidity environments, such as in cloudy or rainy weather with an ambient temperature of 15°C, even though the compressor has already reduced to its lowest speed. This ensures the normal operation of the air conditioning system.

[0021] Simplified control strategy: When applying this invention, the air conditioning unit's cold and hot air dampers only need to be in two states: fully cold end and fully hot end. This simplifies the air conditioning unit's control strategy and reduces the risk of system high-pressure protection shutdown caused by damper step loss, air not passing through or not completely passing through the indoor condenser.

[0022] Precise temperature control: By adjusting the refrigerant flow distribution, excess heat when heating is too hot can be dissipated to the outside environment through the front-end module, or excess cooling when cooling is too cold can be neutralized by heat dissipation, achieving linear change in the air outlet temperature on the passenger compartment side, and enabling more precise control of the air conditioning outlet temperature.

[0023] Improved adjustment accuracy: The system designed in this invention has multiple operating modes. By switching between different modes and adjusting the refrigerant flow, it can meet the needs of different cooling / heating / humidity loads, making the control of indoor temperature more precise. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments disclosed in this invention, the accompanying drawings of the embodiments will be briefly described below. These drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0025] Figure 1 A schematic diagram of the automatic control system for air conditioning cooling and heating based on parallel condensation designed for this invention;

[0026] Figure 2 This is a flowchart of the automatic control method for air conditioning cooling and heating based on parallel condensing in the automatic control system for air conditioning cooling and heating of the present invention.

[0027] Among them, 1—compressor, 2—first solenoid valve, 3—outdoor condenser, 4—heat exchanger, 5—first electronic expansion valve, 6—evaporator, 7—second electronic expansion valve, 8—indoor condenser, 9—air PTC, 10—cooling fan, 11—low temperature radiator, 12—cooling water pump, 13—electric drive unit, 14—second solenoid valve, 15—gas-liquid separator. Detailed Implementation

[0028] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by way of listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In some embodiments, the present invention designs an automatic control system for air conditioning cooling and heating based on parallel condensation, including a refrigerant circuit and a coolant circuit. The refrigerant circuit includes a compressor 1, an outdoor condenser and fan assembly, a heating, ventilation and air conditioning system, and a heat exchanger 4 that exchanges heat with the coolant circuit. The refrigerant circuit can selectively connect or disconnect the compressor 1, the outdoor condenser and fan assembly, the heating, ventilation and air conditioning system, and the heat exchanger 4 through pipelines and valves to form an air conditioning outlet temperature regulation circuit to prevent the air outlet temperature from being too high or too low.

[0030] Example 1

[0031] A specific embodiment of an air conditioner outlet temperature regulation circuit is provided:

[0032] The air conditioner outlet temperature regulation circuit includes a first regulation sub-circuit and a second regulation sub-circuit.

[0033] like Figure 1As shown, the first regulating sub-circuit consists of: compressor 1, indoor condenser 8 of HVAC (indoor condenser 8 and air PTC9 together form indoor condenser and heating components), second electronic expansion valve 7, first electronic expansion valve 5, HVAC evaporator 6 and gas-liquid separator 15 connected in sequence through pipelines.

[0034] The second regulating sub-circuit consists of compressor 1, first solenoid valve 2, outdoor condenser 3 (outdoor condenser 3 and cooling fan 10 together form outdoor condenser and fan assembly), heat exchanger 4, first electronic expansion valve 5 and HVAC evaporator 6 connected in sequence through pipelines.

[0035] Opening the first and second regulating sub-circuits simultaneously can prevent the air conditioner outlet temperature from being too high; opening the first regulating sub-circuit and closing the second regulating sub-circuit can prevent the air conditioner outlet temperature from being too low.

[0036] The present invention also includes a second solenoid valve 14, which is connected to a pipeline. One end of the pipeline is simultaneously connected to the refrigerant outlet of the outdoor condenser 3 and the heat exchanger 4, and the other end is simultaneously connected to the refrigerant outlet of the evaporator 6 and the refrigerant inlet of the gas-liquid separator 15.

[0037] Example 2

[0038] Based on the parallel condenser automatic control system for air conditioning cooling and heating in Embodiment 1, a specific embodiment of an automatic control method for air conditioning cooling and heating is provided:

[0039] I. System Special Operating Strategies (When Cooling Outlet Air is Too Cold / Heating Outlet Air is Too Hot) In normal air conditioning operation mode, when the following two challenging situations occur: the outlet air temperature is too low during normal cooling (users feel too cold), or the outlet air temperature is too high during normal heating (users feel too hot), and the system can no longer reduce cooling / heating capacity through conventional methods such as reducing compressor speed, the passenger cabin controller will automatically trigger a "dehumidification request" signal, activating the core adjustment strategy designed in this patent. This strategy solves the problem through "parallel condensation + precise flow control," with the specific operating logic as follows:

[0040] Refrigerant cycle path (core energy regulation link)

[0041] Compression stage: Compressor 1 starts running and compresses the returned low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant to provide power for the system.

[0042] Parallel condensation stage: The high-pressure, high-temperature gaseous refrigerant is split into two paths here, entering the "parallel condensation" mode to achieve heat diversion and distribution.

[0043] First path (outdoor heat dissipation): The refrigerant enters the outdoor condenser 3 through the first solenoid valve 2 (the outdoor condenser 3 and the cooling fan 10 together form the outdoor condenser and fan assembly, and the cooling fan 10 provides forced airflow for heat exchange), and releases heat by exchanging heat with the outside air to complete the condensation process.

[0044] Second route (in-cabin heating): The refrigerant directly enters the indoor condenser 8 (the indoor condenser 8 and the air PTC9 together form the indoor condenser and heating components, and the air PTC9 is an auxiliary heating component, which can be started and stopped as needed under this condition), and releases heat by exchanging heat with the air in the passenger cabin to provide warm air for the cabin and achieve the heating effect.

[0045] The confluence and throttling stage: After condensation, both refrigerants become low-temperature, high-pressure subcooled liquid refrigerants. They converge in the pipeline and flow into the first electronic expansion valve 5. The first electronic expansion valve 5 performs throttling and pressure reduction functions here, converting the low-temperature, high-pressure liquid refrigerant into a low-temperature, low-pressure gas-liquid two-phase mixture, preparing for subsequent heat absorption.

[0046] Evaporation and reflux stage: The low-temperature, low-pressure refrigerant after throttling enters the evaporator 6, absorbs the heat from the air flowing through it (achieving air cooling), and finally completely vaporizes into gaseous refrigerant. After the gaseous refrigerant passes through the gas-liquid separator 15 to separate any possible residual liquid components (to prevent liquid slugging from damaging the compressor 1), it flows back to the compressor 1, completing the entire refrigerant cycle.

[0047] Air handling process (the process of forming the user's perceived temperature): The air introduced into the air conditioning unit (usually the vehicle's return air or fresh air from outside) needs to undergo precise temperature correction through a "cooling-heating" process before being delivered to the passenger compartment.

[0048] Step 1: Cooling and cooling down: The air first flows through the evaporator 6 and is cooled by the low-temperature refrigerant on the surface of the evaporator 6, thus reducing the temperature (removing some heat).

[0049] Step 2: Heating and warming up: The cooled air then flows through the indoor condenser 8 and is heated by the high-temperature refrigerant on the surface of the indoor condenser 8 (recovering some heat); if the temperature rise requirement is not met, the air PTC9 can start auxiliary heating to further increase the air temperature.

[0050] Step 3: Air delivery into the cabin: After precise adjustment of "cooling first and then heating", the air temperature reaches a comfortable range and is then delivered into the passenger cabin through the air duct to solve the problem of "too cold" or "too hot" in the normal mode.

[0051] II. Control Flow of Air Conditioning-Related Mode Response Strategy in Thermal Management System (Closed-Loop Precise Control Logic) To achieve dynamic stability and precise control of the outlet air temperature, the system operates through a closed-loop process of "parameter reception - signal acquisition - status judgment - execution adjustment - real-time feedback." Each step has a clear control objective and operational logic, such as... Figure 2 As shown, the details are as follows:

[0052] Step S1: Receiving core parameters:

[0053] The system first receives three key command parameters from the air conditioning control module, which serve as the "target benchmark" for adjustment:

[0054] Dehumidification request: The core signal that triggers this strategy indicates that the regular mode can no longer meet the comfort requirements.

[0055] Target air outlet temperature T1: The ideal air outlet temperature preset by the user or system (e.g., 24℃), which is the ultimate goal of adjustment.

[0056] Target evaporation temperature T2: The ideal temperature (e.g., 5℃) that ensures efficient heat exchange in the evaporator 6 without frost formation is the core basis for compressor regulation.

[0057] Step S2: Real-time signal acquisition:

[0058] The thermal management system uses hardware such as temperature sensors to collect two key status signals in real time, which serve as the "current basis" for adjustment:

[0059] Actual outlet air temperature T3: Measured by the temperature sensor at the air outlet, it directly reflects the temperature of the air currently being delivered into the cabin.

[0060] Actual evaporation temperature T4: Measured by a temperature sensor on the tube wall or outlet of evaporator 6, reflecting the actual heat exchange state of evaporator 6.

[0061] Step S3: Air outlet temperature comfort judgment. The actual air outlet temperature T3 collected is compared with the system's preset minimum air outlet temperature threshold TL (e.g., 18℃, below which users will feel too cold) to determine whether the current temperature is within the basic comfort range, thereby determining the subsequent valve control logic.

[0062] Step S4: Valve Status Control (T3 > TL, Minimum Comfort Threshold Met) When the actual outlet air temperature T3 is not lower than the minimum threshold TL, it indicates that the current temperature is not too cold. The temperature needs to be adjusted by a combination of "outdoor heat dissipation + in-cabin heating": Open the first solenoid valve 2: allow the refrigerant to flow into the outdoor condenser 3, and dissipate excess heat through outdoor heat dissipation. Close the second solenoid valve 14: disconnect the refrigerant from other unnecessary circuits, ensuring that the refrigerant circulates according to the preset path.

[0063] Step S41: Valve Status Control (T3≤TL, Minimum Comfort Threshold Not Met) When the actual outlet air temperature T3 is lower than the minimum threshold TL, it indicates that the current temperature is too cold, and outdoor heat dissipation needs to be stopped to prioritize the heating of the cabin: Close the first solenoid valve 2: cut off the path of refrigerant flowing into the outdoor condenser 3 to prevent heat loss to the outside. Close the second solenoid valve 14: similarly cut off other unnecessary circuits to ensure that all refrigerant flows to the indoor condenser 8, maximizing the heating effect inside the cabin.

[0064] Step S5:

[0065] Second electronic expansion valve 7 opening adjustment (in conjunction with flow control in step S4):

[0066] The system calculates and adjusts the opening degree based on the difference between the target outlet temperature T1 and the actual outlet temperature T3 using the first set of incremental PID algorithms (a precise closed-loop control algorithm that can quickly approach the target value and avoid fluctuations; this algorithm is a common technique used by those skilled in the art and will not be elaborated further): If T3 > T1 (actual outlet temperature is too high): the opening degree of the second electronic expansion valve 7 is reduced → the refrigerant flow into the indoor condenser 8 decreases → the heat dissipation of the indoor condenser 8 decreases → the heating capacity of the air weakens → T3 decreases, approaching T1. Through this adjustment, a linear and stable change in outlet temperature is achieved, avoiding sudden cooling and heating. Note: At this time, the first solenoid valve 2 is in the open state. Since the circuit in which the first solenoid valve 2 is located (the second regulation sub-circuit) is open at the same time as the first regulation sub-circuit, the second electronic expansion valve 7 has no throttling effect. Overall, the opening degree of the second electronic expansion valve 7 mainly affects the refrigerant flow rate through the indoor condenser 8. The larger the opening degree of the second electronic expansion valve 7, the larger the flow rate through the indoor condenser 8, and the higher the outlet temperature.

[0067] Step S51:

[0068] The opening of the second electronic expansion valve 7 is adjusted (in conjunction with the flow control in step S41): The system calculates and adjusts the opening based on the difference between the target outlet temperature T1 and the actual outlet temperature T3 using the second set of incremental PID algorithms. If T3 < T1 (actual outlet air is too cold): the opening of the second electronic expansion valve 7 is reduced → the refrigerant flow into the indoor condenser 8 decreases → the compressor discharge pressure increases → the temperature of the air heated by the refrigerant after passing through the indoor condenser 8 is higher → the heating capacity of the air is enhanced → T3 increases, approaching T1. Note: At this time, the first solenoid valve 2 is closed, and only the second adjustment sub-loop exists. The second electronic expansion valve 7 has a throttling effect. Overall, the opening of the second electronic expansion valve 7 mainly affects the discharge pressure of the compressor 1. The higher the discharge pressure of the compressor 1, the higher the refrigerant temperature through the indoor condenser 8, and the higher the outlet air temperature of the air entering the passenger compartment after passing through the indoor condenser.

[0069] Steps S6 and S61: State control of the first electronic expansion valve 5 Under the above two valve control scenarios (S4 and S41), the first electronic expansion valve 5 remains in the fully open state. This is because the core adjustment object of this strategy is "the refrigerant flow rate through the indoor condenser 8 and the exhaust pressure of the compressor 1" (through the second electronic expansion valve 7), and the main function of the first electronic expansion valve 5 is to provide a stable throttling and pressure reduction effect for the evaporator 6. The fully open state can ensure that the evaporator 6 obtains sufficient refrigerant supply and guarantees its cooling capacity foundation.

[0070] After the compressor 1 starts, its rotational speed (which directly determines the refrigerant circulation volume and the system heat exchange capacity) is incrementally PID-adjusted based on the difference between the target evaporation temperature T2 and the actual evaporation temperature T4:

[0071] Step S7: If T4 > T2 (the actual evaporation temperature is too high and the heat exchange capacity of the evaporator 6 is insufficient): Increase the rotational speed of the compressor 1 → Increase the refrigerant circulation volume → Strengthen the heat exchange of the evaporator 6 → Decrease T4 and approach T2.

[0072] Step S71: If T4 < T2 (the actual evaporation temperature is too low and there is a risk of frosting): Decrease the rotational speed of the compressor 1 → Decrease the refrigerant circulation volume → Weaken the heat exchange of the evaporator 6 → Increase T4 and approach T2. Generally, a lower T4 can enhance the cooling and dehumidification effect of the evaporator 6, but it needs to be controlled within the range of not frosting.

[0073] Step S8: Real-time feedback and cyclic regulation The system continuously monitors the actual outlet air temperature T3 and compares it with the preset upper limit TH of the thermal comfort outlet air temperature (such as 28°C, above which users will feel overheated) to form a closed-loop regulation: If T3 ≥ TH (the outlet air is too hot): Return to step S4, open the first solenoid valve 2 to start outdoor heat dissipation, and at the same time adjust the outlet air temperature by the second electronic expansion valve 7. If T3 < TH (the outlet air is not overheated): Return to step S41, close the first solenoid valve 2 to stop outdoor heat dissipation, and give priority to ensuring temperature stability. Through this cyclic judgment and regulation, the system can dynamically respond to temperature changes and always control the outlet air temperature within the comfortable range of [TL, TH].

[0074] In summary, the automatic control system and method for air-conditioning refrigeration and heating based on parallel condensation designed by the present invention have the following technical advantages:

[0075] I. Precise resolution of temperature imbalance and extreme improvement of comfort experience

[0076] To address the issue of traditional systems where the compressor still has excess capacity even at its lowest speed, this invention precisely solves the problems of excessively cold cooling airflow and excessively hot heating airflow by selectively opening and closing and coordinating the operation of dual-loop regulation. When the outlet air temperature is too high, both loops open simultaneously, diverting excess heat through the outdoor condenser 3; when the temperature is too low, only the indoor loop opens, focusing on heating within the cabin. Combined with the differentiated regulation of the second electronic expansion valve 7 based on a PID algorithm—regulating the flow rate of the indoor condenser 8 when both loops are open, and adjusting the discharge pressure of the compressor 1 when only one loop is open—linear changes in outlet air temperature are achieved, completely eliminating user complaints about uncomfortable temperatures.

[0077] II. Optimize system operating parameters to significantly reduce energy consumption.

[0078] Utilizing parallel condensation technology, the system effectively distributes the refrigerant condensation load, significantly reducing system high pressure and decreasing the suction and discharge pressure ratio of compressor 1. Since pressure ratio is positively correlated with energy consumption, this design directly optimizes compressor energy consumption, making it particularly suitable for new energy vehicles and significantly improving overall vehicle range. Simultaneously, the compressor 1 speed is dynamically adjusted based on the difference between the target and actual evaporation temperatures, avoiding ineffective energy consumption and further enhancing energy-saving effects.

[0079] III. Simplify the control logic architecture and reduce system operation risks.

[0080] The system innovatively adopts a dual-state control system for the air conditioning unit's cold and hot air dampers, eliminating complex damper adjustment strategies and fundamentally reducing the risk of high-pressure protection shutdowns caused by damper step loss and insufficient heat exchange. For special operating conditions, the second solenoid valve 14 cuts off unnecessary circuits, ensuring refrigerant circulation along a preset path; the first electronic expansion valve 5 remains fully open to guarantee basic heat exchange in the evaporator 6. These multiple design features significantly reduce the probability of system failure and improve operational stability.

[0081] IV. Adapting to complex working conditions and enhancing system environmental adaptability

[0082] It perfectly addresses operational challenges in diverse environments: for example, when heating at 20°C, it reduces high pressure through diversion condensation to prevent the compressor from shutting down due to excessive pressure; or when cooling at 15°C in cloudy or rainy weather, it precisely controls the evaporation temperature to prevent frost formation on the evaporator. The coordinated control of dual loops and valves enables the system to operate stably under complex conditions such as low load and high humidity, making it far more adaptable than traditional systems.

[0083] It should be noted that the above description of the technical solutions is exemplary, and this specification may be embodied in different forms and should not be construed as limiting itself to the technical solutions set forth herein. Rather, providing these descriptions will ensure that the disclosure of this invention is thorough and complete, and will fully convey the scope of this specification to those skilled in the art. Furthermore, the technical solutions of this invention are defined only by the scope of the claims. When using terms such as "comprising," "having," and "including" as described in this specification, there may also be another part or other components, and the terms used are generally singular but may also represent plural forms. It should be pointed out that although various different components may appear and be described in this specification using terms such as "first," "second," "top," "bottom," "one side," "the other side," "one end," "the other end," etc., these components and parts should not be limited by these terms. These terms are only used to distinguish one component and part from another component and part. For example, without departing from the scope of this specification, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component; top and bottom components may, in certain cases, be interchanged or converted; components at one end and at the other end may have the same or different performance characteristics.

[0084] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention should be considered within the protection scope of the present invention.

Claims

1. An automatic control system for air conditioning cooling and heating based on parallel condensation, comprising a refrigerant circuit and a coolant circuit, wherein the refrigerant circuit includes a compressor (1), an outdoor condenser and fan assembly, a heating, ventilation and air conditioning system, and a heat exchanger (4) that exchanges heat with the coolant circuit; characterized in that: The refrigerant circuit can be connected or disconnected from the compressor (1), the outdoor condenser and fan assembly, the HVAC and the heat exchanger (4) through pipelines and valves to form an air conditioner outlet temperature regulation circuit to prevent the air conditioner outlet temperature from being too high or too low. The air conditioner outlet temperature regulation circuit includes a first regulation sub-circuit and a second regulation sub-circuit. The first regulating sub-circuit includes the compressor (1), the indoor condenser and heating components of the HVAC system, and the evaporator (6) of the HVAC system, which are connected in series through pipelines and valves. The second regulating sub-circuit includes the compressor (1), the outdoor condenser and fan assembly, the heat exchanger (4) and the evaporator (6) connected in series by pipelines and valves. The simultaneous opening of the first and second regulating sub-circuits can prevent the air conditioner outlet temperature from being too high; the opening of the first regulating sub-circuit and the closing of the second regulating sub-circuit can prevent the air conditioner outlet temperature from being too low.

2. The automatic control system for air conditioning cooling and heating based on parallel condensation as described in claim 1, characterized in that: A first electronic expansion valve (5) is provided on the pipe connected to the refrigerant inlet of the evaporator (6), and a second electronic expansion valve (7) is provided on the pipe connected to the refrigerant outlet of the indoor condenser and heating assembly.

3. The automatic control system for air conditioning cooling and heating based on parallel condensation as described in claim 1, characterized in that: A first solenoid valve (2) is installed on the pipeline connected to the refrigerant inlet of the outdoor condenser and fan assembly.

4. An automatic control method for air conditioning cooling and heating based on the parallel condensing automatic control system for air conditioning cooling and heating according to any one of claims 1-3, characterized in that: It includes automatic control methods for air conditioner outlet temperature that is too low and automatic control methods for air conditioner outlet temperature that is too high. The automatic control method for the air conditioner outlet temperature being too low includes: determining whether the air conditioner outlet temperature is too low; if the air conditioner outlet temperature is too low, opening the first adjustment sub-circuit, closing the second adjustment sub-circuit, adjusting the refrigerant flow rate entering the evaporator (6) through the indoor condenser and heating components, and increasing the air conditioner outlet temperature. The automatic control method for excessively high air outlet temperature includes: determining whether the air outlet temperature is too high; if the air outlet temperature is too high, simultaneously opening the first regulating sub-circuit and the second regulating sub-circuit to adjust the refrigerant flow through the indoor condenser and heating components, thereby reducing the air outlet temperature.

5. The automatic control method for air conditioning cooling and heating based on parallel condensing automatic control system as described in claim 4, characterized in that: The automatic control method for adjusting the air outlet temperature to be too low also includes: obtaining the actual evaporation temperature T4, setting the target evaporation temperature T2, and adjusting the refrigerant flow rate entering the evaporator (6) after passing through the indoor condenser and heating components, so that the actual evaporation temperature T4 is raised to the target evaporation temperature T2.

6. The automatic control method for air conditioning cooling and heating based on parallel condensing automatic control system as described in claim 4, characterized in that: The automatic control method for excessively high outlet temperature further includes: obtaining the actual evaporation temperature T4, setting the target evaporation temperature T2, and adjusting the refrigerant flow rate through the indoor condenser and heating components to reduce the actual evaporation temperature T4 to the target evaporation temperature T2.

7. The automatic control method for air conditioning cooling and heating based on parallel condensing automatic control system as described in claim 4, characterized in that: The method for determining whether the air conditioner outlet temperature is too low includes: obtaining the actual air outlet temperature T3 of the air conditioner outlet, setting the low temperature threshold TL and duration TIME1 of the air conditioner outlet, and if T3≤TL and the duration reaches TIME1, then the air conditioner outlet temperature is too low. The method for determining that the air conditioner outlet temperature is too high includes: obtaining the actual air outlet temperature T3 of the air conditioner outlet, setting the high temperature threshold TH and duration TIME2 of the air conditioner outlet, and if T3≥TH and the duration reaches TIME2, then the air conditioner outlet temperature is too high.

8. The automatic control method for air conditioning cooling and heating based on parallel condensing automatic control system as described in claim 7, characterized in that: The method of adjusting the refrigerant flow rate entering the evaporator (6) through the indoor condenser and heating components to increase the air outlet temperature includes: setting a target air outlet temperature T1, calculating the difference between the target air outlet temperature T1 and the actual air outlet temperature T3, and reducing the refrigerant flow rate entering the evaporator (6) through the indoor condenser and heating components according to the incremental PID control algorithm, so that the actual air outlet temperature T3 of the air outlet increases to the target air outlet temperature T1 of the air outlet. The method for adjusting the refrigerant flow rate through the indoor condenser and heating components to reduce the air conditioner outlet temperature includes: setting a target air outlet temperature T1, calculating the difference between the target air outlet temperature T1 and the actual air outlet temperature T3, and reducing the refrigerant flow rate through the indoor condenser and heating components according to an incremental PID control algorithm, so that the actual air outlet temperature T3 is reduced to the target air outlet temperature T1.

9. The automatic control method for air conditioning cooling and heating based on parallel condensing automatic control system as described in claim 5, characterized in that: The method for adjusting the refrigerant flow rate entering the evaporator (6) after passing through the indoor condenser and heating components includes: calculating the difference between the target evaporation temperature T2 and the actual evaporation temperature T4, and reducing the refrigerant flow rate entering the evaporator (6) after passing through the indoor condenser and heating components according to the incremental PID control algorithm.

10. The automatic control method for air conditioning cooling and heating based on parallel condensing automatic control system as described in claim 6, characterized in that: The method for adjusting the refrigerant flow rate through the indoor condenser and heating assembly includes: calculating the difference between the target evaporation temperature T2 and the actual evaporation temperature T4, and reducing the refrigerant flow rate through the indoor condenser and heating assembly according to an incremental PID control algorithm.

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