Double-evaporator air conditioning system of new energy automobile and control method

Abstract

The invention provides a double-evaporator air conditioning system of a new energy automobile and a control method, and relates to the technical field of new energy automobile air conditioning design and control, the double-evaporator air conditioning system comprises a compressor, a condenser, a liquid storage tank, a front expansion valve, a rear expansion valve, a front evaporator and a rear evaporator, refrigerant enters the liquid storage tank through the condenser, the liquid storage tank respectively enters the front expansion valve and the rear expansion valve through the three-way valve, the front expansion valve is connected with the front evaporator, the rear expansion valve is connected with the rear evaporator, and the front evaporator and the rear evaporator are connected with the compressor to form a complete cycle. According to the invention, the problems of non-uniform temperature in the vehicle, high energy consumption of the whole vehicle and frosting protection of the evaporator are solved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of air-conditioning design and control of new energy vehicles, and in particular to a dual-evaporator air-conditioning system and a control method for a new energy vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] There are currently two mainstream solutions for the air conditioning system of new energy VAN models in the industry: The first solution is the traditional single compressor, single evaporator fixed frequency control method, but this method has the following disadvantages:

[0004] 1) Compressor fixed frequency control leads to high energy consumption, easy frost protection of evaporator, and frequent start and stop of compressor;

[0005] 2) The single evaporator is installed at the front of the vehicle, resulting in good cooling effect in the driving area and poor cooling effect in the passenger area, resulting in uneven temperature in the vehicle;

[0006] The first solution is to use a dual compressor and dual evaporator variable frequency control method. This method can solve the shortcomings of the first method, but it will also cause new problems, including:

[0007] 1) The second method is more expensive, the material cost of each vehicle increases, and the cost of purchasing a vehicle for customers increases, which customers are unwilling to accept, resulting in low vehicle sales;

[0008] 2) The pipeline layout of the whole vehicle is complicated, resulting in waste of vehicle space. Summary of the invention

[0009] In order to solve the above problems, the present invention proposes a dual-evaporator air-conditioning system and control method for a new energy vehicle, which adopts a single compressor and dual-evaporator variable frequency control, and adjusts the compressor speed, the front expansion valve opening, the rear expansion valve opening, the front evaporator wind speed and the rear evaporator wind speed through the control method of the air-conditioning controller, thereby realizing the temperature control of the whole vehicle.

[0010] According to some embodiments, the present disclosure adopts the following technical solutions:

[0011] A dual-evaporator air-conditioning system for a new energy vehicle comprises a compressor, a condenser, a liquid storage tank, a front expansion valve, a rear expansion valve, a front evaporator and a rear evaporator, wherein the compressor is connected to the condenser, the refrigerant enters the liquid storage tank through the condenser, the liquid storage tank enters the front expansion valve and the rear expansion valve respectively through a three-way valve, the front expansion valve is connected to the front evaporator, the rear expansion valve is connected to the rear evaporator, the front evaporator and the rear evaporator are connected to the compressor to form a complete cycle.

[0012] According to some embodiments, the present disclosure adopts the following technical solutions:

[0013] A control method for a dual-evaporator air conditioning system of a new energy vehicle, comprising:

[0014] Get the temperature of the front evaporator return air outlet, set the difference between the front evaporator return air outlet temperature and the set temperature in the car, and the difference between the rear evaporator return air outlet temperature and the set temperature in the car. Each time the compressor is started, set the compressor speed, and then start sending speed requests to the compressor according to the compressor speed change rate. After a period of time, automatically adjust the speed according to the working mode; adjust the gear according to the temperature. If it is already the lowest or highest gear, the gear remains unchanged. When jumping out of the current temperature range, the gear is reset to zero to realize the variable frequency control of the compressor.

[0015] Furthermore, the front evaporator core temperature and the rear evaporator core temperature sensor are used to obtain the rear evaporator core. According to the core temperature range, the compressor enters the frequency reduction mode, and the frequency operation is reduced by running for 20 seconds each time the frequency drops one level. In the compressor frequency reduction mode, the compressor frequency operation mode is adjusted according to the defrost temperature setting. After defrost protection, when it is detected that the defrost temperature exceeds the threshold, the defrost protection is exited; the compressor resumes normal operation to realize the defrost protection control of the compressor.

[0016] According to some embodiments, the present disclosure adopts the following technical solutions:

[0017] A non-transitory computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by a processor, a control method for a dual-evaporator air-conditioning system of a new energy vehicle is implemented.

[0018] According to some embodiments, the present disclosure adopts the following technical solutions:

[0019] An electronic device comprises: a processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory so that the electronic device executes the control method for a dual-evaporator air-conditioning system of a new energy vehicle.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention adopts a single compressor and dual evaporator variable frequency control scheme, and the air conditioning system of the scheme mainly includes: compressor, condenser, liquid storage tank, front expansion valve, front evaporator, front evaporator fan, rear expansion valve, rear evaporator, and rear evaporator fan. The compressor frequency and refrigerant flow time-varying control strategy is adopted, and the input signals of the strategy mainly include the current front evaporator core temperature, front evaporator return air outlet temperature, front evaporator set temperature, rear evaporator core temperature, rear evaporator return air outlet temperature, rear evaporator set temperature, front evaporator fan set wind speed, and rear evaporator fan set wind speed; the output signals mainly include the compressor speed of the control target, the front expansion valve opening, the rear expansion valve opening, the front evaporator fan wind speed, and the rear evaporator fan wind speed, which can solve the problems of uneven temperature in the car, high energy consumption of the whole vehicle, evaporator frosting protection, etc., and can also solve the problems of high vehicle cost, complex layout, and space waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure.

[0023] Figure 1 A schematic diagram of system structure connection of an embodiment of the present disclosure;

[0024] Figure 2 A schematic diagram of signal composition of a system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0026] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0027] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0028] Example 1

[0029] In one embodiment of the present disclosure, a dual-evaporator air-conditioning system for a new energy vehicle is provided, including a compressor, a condenser, a liquid storage tank, a front expansion valve, a rear expansion valve, a front evaporator and a rear evaporator. The compressor is connected to the condenser, and the refrigerant enters the liquid storage tank through the condenser. The liquid storage tank enters the front expansion valve and the rear expansion valve respectively through a three-way valve. The front expansion valve is connected to the front evaporator, and the rear expansion valve is connected to the rear evaporator. The front evaporator and the rear evaporator are connected to the compressor to form a complete cycle.

[0030] As an embodiment, the compressor is connected to the condenser through a pipeline, the condenser is connected to the liquid storage tank, the refrigerant comes out of the liquid storage tank and passes through a three-way valve to be connected to the front expansion valve and the rear expansion valve respectively, the front expansion valve is connected to the front evaporator, the rear expansion valve is connected to the rear evaporator, and finally the refrigerant returns to the compressor through the evaporator; single compressor, single condenser, double evaporators, the double evaporators are designed in parallel;

[0031] Furthermore, the opening of the front expansion valve and the rear expansion valve is controlled by the air-conditioning controller to achieve real-time adjustment; the compressor can be controlled by the air-conditioning controller to achieve variable frequency operation; and a time-varying control strategy for the compressor frequency and refrigerant flow is implemented.

[0032] As an embodiment, the air-conditioning system is connected to a temperature sensor, and multiple temperature sensors are set, which are respectively set at the front evaporator core, the front evaporator return air outlet, the rear evaporator core and the rear evaporator return air outlet. The sensors are used to collect the temperature of the front evaporator core, the temperature of the front evaporator return air outlet, the front evaporator set temperature, the temperature of the rear evaporator core, the temperature of the rear evaporator return air outlet and the rear evaporator set temperature.

[0033] The air-conditioning system also includes an air-conditioning controller, which is connected to a temperature sensor. The temperature sensor transmits collected temperature data to the air-conditioning controller. The air-conditioning controller analyzes the temperature data and formulates control instructions. The instructions control and adjust the compressor speed, the front expansion valve opening, the rear expansion valve opening, the front evaporator wind speed, and the rear evaporator wind speed to achieve vehicle temperature control.

[0034] The air conditioning controller obtains the temperature of the front evaporator return air outlet through the temperature sensor of the front evaporator return air outlet, sets the difference between the front evaporator return air outlet temperature and the set temperature in the car, and the difference between the rear evaporator return air outlet temperature and the set temperature in the car, sets the speed of the compressor each time the compressor is started, starts sending speed requests to the compressor according to the speed change rate of the compressor, and automatically adjusts the speed according to the working mode after a period of time.

[0035] The air conditioning controller obtains the front evaporator core temperature through the front evaporator core temperature sensor and the rear evaporator core temperature through the rear evaporator core temperature sensor, and selects the frequency operation mode of the compressor according to the obtained core temperatures to realize defrost protection control of the compressor.

[0036] As an embodiment, the air conditioning system mainly includes: a compressor, a condenser, a liquid storage tank, a front expansion valve, a front evaporator, a front evaporating fan, a rear expansion valve, a rear evaporator, and a rear evaporating fan. The compressor is connected to the condenser, the refrigerant enters the liquid storage tank through the condenser, the liquid storage tank enters the front expansion valve and the rear expansion valve respectively through the three-way valve, the front expansion valve is connected to the front evaporator, the rear expansion valve is connected to the rear evaporator, the front evaporator and the rear evaporator are connected to the compressor, thus forming a complete cycle.

[0037] The control strategy of the air-conditioning system includes: by collecting the current front evaporator core temperature, front evaporator return air outlet temperature, front evaporator set temperature, rear evaporator core temperature, rear evaporator return air outlet temperature, rear evaporator set temperature, front evaporator set wind speed, rear evaporator set wind speed and other information, and adjusting the compressor speed, front expansion valve opening, rear expansion valve opening, front evaporator wind speed, rear evaporator wind speed through the control strategy of the air-conditioning controller, thereby achieving vehicle temperature control and solving problems such as uneven temperature in the vehicle, high vehicle energy consumption, and evaporator frost protection.

[0038] When the set temperature in the car is 26℃, the temperature inside the car is balanced and the cooling effect is consistent front and rear.

[0039] (1) The air conditioning controller obtains the temperature of the front evaporator return air outlet through the front evaporator return air outlet temperature sensor. Let △T1 be the difference between the front evaporator return air outlet temperature and the set temperature in the car, and △T2 be the difference between the rear evaporator return air outlet temperature and the set temperature in the car. Each time the compressor is started, the compressor speed is set to 3000 rpm, and then the speed request is sent to the compressor according to the compressor speed change rate. After 30 seconds, the speed is automatically adjusted according to the working mode. When △t≥2℃, the compressor gear is in the same temperature range for more than 2 minutes, and the speed is increased by one gear until the highest gear. Similarly, when △t≤-2℃, the speed is reduced by one gear until the lowest gear. If it is already the lowest gear or the highest gear, the gear remains unchanged. When jumping out of the current temperature range, the gear is reset. The compressor works at one gear for at least 30 seconds. This strategy realizes the variable frequency control of the compressor.

[0040] (2) The air conditioning controller obtains the front evaporator core temperature through the front evaporator core temperature sensor and the rear evaporator core temperature through the rear evaporator core temperature sensor. When the core temperature is <=4 degrees, the compressor enters the frequency reduction mode and reduces the frequency by 20 seconds for each frequency reduction. In the compressor frequency reduction mode, when the defrost temperature is >=7 degrees, the compressor frequency reduction mode is exited. When the defrost temperature is <=2 degrees, the compressor enters the speed limit mode and the compressor runs at 1500 rpm. In the speed limit mode, if the defrost temperature is detected to be <=1 degree, or the defrost temperature is <=2 degrees for 120 seconds, the defrost protection mode is entered and the compressor stops. After the defrost protection, when the defrost temperature is detected to be >=5 degrees, the defrost protection is exited. The compressor resumes normal operation. This strategy implements the defrost protection control of the compressor.

[0041] As follows, compressor speed table 1:

[0042] Maximum compressor speed J4 (advanced parameter setting)

[0043] Minimum compressor speed J5 (advanced parameter setting)

[0044] Minimum adjustment range: F = (J4-J5) / 24.

[0045] When heating up, the compressor gear D corresponds to the speed: J5-F+F*2*D

[0046] When cooling down, the compressor gear position d corresponds to the speed: J5+F*2*(d-1)

[0047] Table 1 Compressor speed table

[0048]

[0049]

[0050] (3) Let △T3 be the difference between the return air outlet temperature of the front evaporator and the return air outlet temperature of the rear evaporator. According to the difference of △T3, the existing PID control algorithm is used to adjust the opening of the front expansion valve and the rear expansion valve, so as to finally achieve the same return air outlet temperature of the front and rear evaporators, and then achieve the temperature balance in the car. This strategy realizes the uniform control of the front and rear temperatures in the car.

[0051] Example 2

[0052] An embodiment of the present disclosure provides a control method for a dual-evaporator air conditioning system of a new energy vehicle, including:

[0053] Get the temperature of the front evaporator return air outlet, set the difference between the front evaporator return air outlet temperature and the set temperature in the car, and the difference between the rear evaporator return air outlet temperature and the set temperature in the car. Each time the compressor is started, set the compressor speed, and then start sending speed requests to the compressor according to the compressor speed change rate. After a period of time, automatically adjust the speed according to the working mode; adjust the gear according to the temperature. If it is already the lowest or highest gear, the gear remains unchanged. When jumping out of the current temperature range, the gear is reset to zero to realize the variable frequency control of the compressor.

[0054] The front evaporator core temperature and the rear evaporator core temperature sensor are used to obtain the rear evaporator core. According to the core temperature range, the compressor enters the frequency reduction mode, and the frequency operation is reduced by running for 20 seconds at each frequency reduction. In the compressor frequency reduction mode, the compressor frequency operation mode is adjusted according to the defrost temperature setting. After defrost protection, when it is detected that the defrost temperature exceeds the threshold, the defrost protection is exited; the compressor resumes normal operation to realize the defrost protection control of the compressor.

[0055] Specifically, when the set temperature in the car is 26°C, the temperature inside the car is balanced and the cooling effect is consistent between the front and rear.

[0056] (1) The air conditioning controller obtains the temperature of the front evaporator return air outlet through the front evaporator return air outlet temperature sensor. Let △T1 be the difference between the front evaporator return air outlet temperature and the set temperature in the car, and △T2 be the difference between the rear evaporator return air outlet temperature and the set temperature in the car. Each time the compressor is started, the compressor speed is set to 3000 rpm, and then the speed request is sent to the compressor according to the compressor speed change rate. After 30 seconds, the speed is automatically adjusted according to the working mode. When △t≥2℃, the compressor gear is in the same temperature range for more than 2 minutes, and the speed is increased by one gear until the highest gear. Similarly, when △t≤-2℃, the speed is reduced by one gear until the lowest gear. If it is already the lowest gear or the highest gear, the gear remains unchanged. When jumping out of the current temperature range, the gear is reset. The compressor works at one gear for at least 30 seconds. This strategy realizes the variable frequency control of the compressor.

[0057] (2) The air conditioning controller obtains the front evaporator core temperature through the front evaporator core temperature sensor and the rear evaporator core temperature through the rear evaporator core temperature sensor. When the core temperature is <=4 degrees, the compressor enters the frequency reduction mode and reduces the frequency by 20 seconds for each frequency reduction. In the compressor frequency reduction mode, when the defrost temperature is >=7 degrees, the compressor frequency reduction mode is exited. When the defrost temperature is <=2 degrees, the compressor enters the speed limit mode and the compressor runs at 1500 rpm. In the speed limit mode, if the defrost temperature is detected to be <=1 degree, or the defrost temperature is <=2 degrees for 120 seconds, the defrost protection mode is entered and the compressor stops. After the defrost protection, when the defrost temperature is detected to be >=5 degrees, the defrost protection is exited. The compressor resumes normal operation. This strategy implements the defrost protection control of the compressor.

[0058] (3) Let △T3 be the difference between the return air outlet temperature of the front evaporator and the return air outlet temperature of the rear evaporator. According to the difference of △T3, the existing PID control algorithm is used to adjust the opening of the front expansion valve and the rear expansion valve, so as to finally achieve the same return air outlet temperature of the front and rear evaporators, and then achieve the temperature balance in the car. This strategy realizes the uniform control of the front and rear temperatures in the car.

[0059] Example 3

[0060] An embodiment of the present disclosure provides a non-transitory computer-readable storage medium, which is used to store computer instructions. When the computer instructions are executed by a processor, a control method for a dual-evaporator air-conditioning system of a new energy vehicle is implemented.

[0061] Example 4

[0062] An embodiment of the present disclosure provides an electronic device, including: a processor, a memory, and a computer program; wherein the processor is connected to the memory, and the computer program is stored in the memory. When the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes the control method for a dual-evaporator air-conditioning system of a new energy vehicle.

[0063] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0064] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0065] Although the above describes the specific implementation methods of the present disclosure in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present disclosure. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims

1. A dual-evaporator air-conditioning system for new energy vehicles, characterized in that: It includes a compressor, a condenser, a liquid storage tank, a front expansion valve, a rear expansion valve, a front evaporator and a rear evaporator. The compressor is connected to the condenser, and the refrigerant enters the liquid storage tank through the condenser. The liquid storage tank enters the front expansion valve and the rear expansion valve respectively through a three-way valve. The front expansion valve is connected to the front evaporator, and the rear expansion valve is connected to the rear evaporator. The front evaporator and the rear evaporator are connected to the compressor to form a complete cycle.

2. A dual-evaporator air-conditioning system for a new energy vehicle according to claim 1, characterized in that: The front expansion valve and the rear expansion valve are connected in parallel.

3. The dual-evaporator air-conditioning system for a new energy vehicle according to claim 1, characterized in that: The air conditioning system is connected to a temperature sensor, which is used to collect the temperature of the front evaporator core, the front evaporator return air outlet temperature, the front evaporator set temperature, the temperature of the rear evaporator core, the rear evaporator return air outlet temperature and the rear evaporator set temperature.

4. The dual-evaporator air-conditioning system for a new energy vehicle according to claim 1, characterized in that: The air-conditioning system also includes an air-conditioning controller, which is connected to a temperature sensor. The temperature sensor transmits the collected temperature data to the air-conditioning controller. The air-conditioning controller analyzes the temperature data and formulates control instructions. The instructions control and adjust the compressor speed, the front expansion valve opening, the rear expansion valve opening, the front evaporator wind speed, and the rear evaporator wind speed to achieve vehicle temperature control.

5. A dual-evaporator air-conditioning system for a new energy vehicle as claimed in claim 4, characterized in that: The air conditioning controller obtains the front evaporator return air outlet temperature through the front evaporator return air outlet temperature sensor, sets the difference between the front evaporator return air outlet temperature and the set temperature in the vehicle, and the difference between the rear evaporator return air outlet temperature and the set temperature in the vehicle. It sets the compressor speed each time the compressor is started, starts sending speed requests to the compressor based on the compressor speed change rate, and automatically adjusts the speed according to the working mode after a period of time.

6. A dual-evaporator air-conditioning system for a new energy vehicle as claimed in claim 4, characterized in that: The air conditioning controller obtains the front evaporator core temperature through the front evaporator core temperature sensor and the rear evaporator core temperature through the rear evaporator core temperature sensor, and selects the frequency operation mode of the compressor according to the obtained core temperature to realize the defrost protection control of the compressor.

7. A control method for a dual-evaporator air-conditioning system for a new energy vehicle according to any one of claims 1 to 6, characterized in that: include: Get the front evaporator return air outlet temperature, set the difference between the front evaporator return air outlet temperature and the set temperature in the car, and the difference between the rear evaporator return air outlet temperature and the set temperature in the car. Each time the compressor is started, set the compressor speed, and then start sending speed requests to the compressor according to the compressor speed change rate. After a period of time, the speed is automatically adjusted according to the working mode; adjust the gear according to the temperature. If it is already the lowest or highest gear, the gear remains unchanged. When jumping out of the current temperature range, the gear is reset to zero to realize the variable frequency control of the compressor.

8. The method according to claim 7, wherein: include: The front evaporator core temperature and the rear evaporator core temperature sensor are used to obtain the rear evaporator core temperature. Based on the core temperature range, the compressor enters the frequency reduction mode and reduces the frequency by 20 seconds for each frequency reduction. In the compressor frequency reduction mode, the compressor frequency operation mode is adjusted according to the defrost temperature setting. After the defrost protection is in effect, if the defrost temperature exceeds the threshold, the defrost protection is exited. The compressor resumes normal operation, realizing the defrost protection control of the compressor.

9. A non-transitory computer-readable storage medium, characterized in that The non-transitory computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by the processor, the control method of the dual-evaporator air-conditioning system of a new energy vehicle as described in any one of claims 7-8 is implemented.

10. An electronic device, characterized in that: include: A processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to execute a control method for a dual-evaporator air-conditioning system of a new energy vehicle as described in any one of claims 7-8.

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