Control method of fluorine pump heat pipe air conditioner with double evaporators

Abstract

The invention discloses a control method of a fluorine pump heat pipe air conditioner with double evaporators, and relates to the technical field of automatic control, the control method comprises a control system, the control system automatically switches operation modes according to different temperature scenes, and the operation modes comprise a compressor mode, an energy-saving mode and a mixed refrigeration mode. The double-evaporator air conditioner has the advantages that the two evaporators are arranged, work at the same time in all the operation modes and operate according to the set superheat degree, the heat exchange efficiency is greatly improved, and when a traditional single-evaporator air conditioner faces complex indoor and outdoor environments and various cooling and heating load requirements, the heat exchange capacity is limited, and the heat exchange efficiency is poor. The double evaporators can rapidly and efficiently achieve indoor and outdoor heat exchange, in a large building, the cooling and heating load difference is large due to different room orientations and functions, the double evaporators can be adjusted according to the actual conditions of all areas, the indoor temperature is rapidly adjusted to the set value, and the comfort degree of a user is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of automatic control, and in particular to a control method for a fluorine pump heat pipe air conditioner with a double evaporator. Background Art

[0002] In many application scenarios, such as large data centers, commercial complexes, and high-end residences, there are strict requirements for the cooling and heating efficiency of air conditioners. Electronic equipment in large data centers continuously generates a large amount of heat. If the heat cannot be dissipated in a timely and efficient manner, it will seriously affect the normal operation and service life of the equipment; commercial complexes are large in space, densely populated, and complex in functional divisions. The cooling and heating loads in different areas vary significantly, requiring the air conditioning system to be able to quickly and accurately adjust the temperature. Traditional single-evaporator air conditioners gradually reveal their limitations when facing these complex thermal environments. At the same time, energy conservation issues have also attracted much attention. In the context of global advocacy of energy conservation and emission reduction, air conditioners, as a major energy consumer, are of vital importance in improving their energy-saving performance. The continuous increase in energy costs has also prompted people to actively seek more efficient and energy-saving air conditioning technologies. By optimizing the operating mode and control strategy of the air conditioning system and reducing energy consumption, it can not only save users a lot of operating costs, but also help alleviate the current energy shortage and achieve sustainable development.

[0003] The existing technology has certain defects. First, the existing technology is mostly a single evaporator with limited heat exchange capacity, which is difficult to adapt to complex environments and various cold and hot loads, and cannot quickly and accurately adjust the indoor temperature, resulting in poor comfort. Secondly, the traditional air-conditioning has a single operating mode and cannot automatically switch according to different temperature scenes and heat loads. It is difficult to maintain efficient operation under various working conditions and the usage scenarios are limited. Moreover, the existing air-conditioning has low refrigerant flow control accuracy, low evaporator working efficiency, and lacks an automatic mode switching mechanism, resulting in high energy consumption and low energy efficiency ratio. Finally, traditional air-conditioning is prone to shutdown when components fail, affecting comfort, and lacks precise monitoring and control. Pressure and temperature fluctuations are prone to failures, and the maintenance cost and downtime are long. For this reason, we propose a control method for a fluorine pump heat pipe air conditioner with a dual evaporator. Summary of the invention

[0004] The object of the present invention is to provide a control method for a fluorine pump heat pipe air conditioner with a double evaporator.

[0005] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: a control method for a fluorine pump heat pipe air conditioner with a dual evaporator, the control method comprising a control system, the control system automatically switches the operation mode according to different temperature scenes, the operation mode comprising a compressor mode, an energy-saving mode and a mixed refrigeration mode, characterized in that the control method has the following specific steps:

[0006] Step 1: Start preparation, start the control system, and then turn on the indoor EC speed-adjustable fan;

[0007] Step 2: Expansion valve control: for the compressor electronic expansion valve EEV2, according to the suction temperature 2 (T s2 ) and suction pressure 2(P s2 ) Calculate superheat S h2 , the calculation formula is:

[0008] S h2 =T s2 -T sat (P s2 )

[0009] Among them, T sat (P s2 ) is based on P s2 Check the value obtained from the refrigerant saturation temperature table to automatically adjust the opening of EEV2. For the heat pipe electronic expansion valve EEV1, according to the suction temperature 1 (T s1 ) and suction pressure 1(P s1 ) Calculate superheat S h1 , T sat (P s1 ) is based on P s1 Check the refrigerant saturation temperature table to obtain the value, and the calculation formula is:

[0010] S h1 =T s1 -T sat (P s1 )

[0011] Automatically control the opening of EEV1;

[0012] Step 3: Determine the operation mode according to different temperature scenarios. In compressor mode, open solenoid valve 1 and close solenoid valve 2. In energy-saving mode, open solenoid valve 2 and close solenoid valve 1. In mixed cooling mode, close solenoid valve 2 and open solenoid valve 1.

[0013] Step 4: Component operation control:

[0014] Compressor mode: Start the compressor and adjust the pressure according to the condensing pressure sensor data P C , adjust the outdoor unit variable frequency fan speed N through the PID control algorithm fan , the formula is:

[0015]

[0016] Among them, P set is the preset condensation pressure threshold, K p is the proportionality coefficient, ∫(P C -P set)dt represents the integral term from the start time to the current time, K i Indicates the integral coefficient, K d is the differential coefficient, dt is the time differential term, and d is the differential operation;

[0017] Energy-saving mode: turn on the outdoor unit fan, fluorine pump and fluorine pump solenoid valve, and adjust the heat pipe EEV1 to the maximum opening;

[0018] Mixed refrigeration mode: turn on the fluorine pump and close the fluorine pump solenoid valve, the heat pipe EEV1 works according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point;

[0019] Step 5: Mode switching. In automatic mode, the energy-saving mode, compressor mode and mixed refrigeration mode are automatically switched according to the preset switching time setting value, so that the system can operate efficiently under different working conditions and improve the energy efficiency ratio of the whole machine.

[0020] As a further solution of the present invention: in the compressor mode, the system opens solenoid valve 1 and closes solenoid valve 2. After starting the compressor, the outdoor unit variable frequency fan speed control output is automatically adjusted according to the pressure detected by the condensing pressure sensor, and the fluorine pump and the fluorine pump solenoid valve are in a closed state.

[0021] As a further solution of the present invention: in the energy-saving mode, the system opens the solenoid valve 2, closes the solenoid valve 1, turns on the outdoor fan, the fluorine pump and the fluorine pump solenoid valve are turned on and operated, and the heat pipe EEV1 operates at the maximum opening.

[0022] As a further solution of the present invention: in the mixed refrigeration mode, the system closes solenoid valve 2, opens solenoid valve 1, closes the fluorine pump solenoid valve, starts running the fluorine pump, the heat pipe EEV1 works according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point.

[0023] As a further solution of the present invention: in the automatic mode, the switching between the energy-saving mode, the compressor mode and the mixed refrigeration mode is performed according to the switching time setting value, and the switching steps are as follows:

[0024] S1, first turn on the indoor fan;

[0025] S2, open EEV1 and EEV2 respectively, and control their operation according to the corresponding suction pressure and suction temperature;

[0026] S3, control the opening and closing of solenoid valve 1 and solenoid valve 2 according to different mode requirements;

[0027] S4. Determine the outdoor fan operating speed based on the outdoor temperature and pipeline condensing pressure, and start the corresponding compressor and fluorine pump.

[0028] As a further solution of the present invention: the control method uses a central control main control board to control various components of the refrigeration system, including sending control instructions to the compressor drive board, various solenoid valves, electronic expansion valves, outdoor fans and fluorine pumps.

[0029] As a further solution of the present invention: the control method also includes collecting data through suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1 and suction temperature 2 sensors, and transmitting the data to the central control main control board to achieve precise control of each component.

[0030] As a further solution of the present invention: when the energy-saving mode, compressor mode and mixed refrigeration mode are running, the air supply fan is always kept on to provide refrigeration circulating air for the room.

[0031] As a further solution of the present invention: the control method also includes in each operating mode, when it is detected that any parameter among the suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1 and suction temperature 2 exceeds the preset safety threshold, the central control main control board issues an alarm and controls the corresponding components to adjust the operating status or stop operating to ensure the safe and stable operation of the air-conditioning system.

[0032] As a further solution of the present invention: Compressor mode:

[0033] When the system runs the compressor cooling mode, the control system first turns on the indoor EC speed-adjusting fan, the compressor electronic expansion valve EEV2 automatically controls the operation according to the superheat calculated by the suction temperature 2, and the heat pipe electronic expansion valve EEV1 automatically controls the operation according to the superheat calculated by the suction temperature 1. The system opens the solenoid valve 1 and closes the solenoid valve 2. After starting the compressor, the outdoor unit variable frequency fan speed control output is automatically adjusted according to the pressure detected by the condensing pressure sensor. The two evaporators work at the same time, each operating according to the set superheat.

[0034] As a further solution of the present invention: Energy saving mode:

[0035] When the system runs in energy-saving mode, the control system first turns on the indoor EC speed-adjusting fan, the compressor electronic expansion valve EEV2 automatically controls the operation according to the superheat calculated by the suction temperature 2, and the heat pipe electronic expansion valve EEV1 automatically controls the operation according to the superheat calculated by the suction temperature 1. The control system opens the solenoid valve 2 and closes the solenoid valve 1. The system turns on the outdoor unit fan, and the fluorine pump runs in energy-saving mode for cooling. The two evaporators work at the same time, each running according to the set superheat.

[0036] As a further solution of the present invention: mixed refrigeration:

[0037] When the system runs in mixed cooling mode, the control system first turns on the indoor EC speed-adjustable fan, the compressor electronic expansion valve EEV2 automatically controls the operation according to the superheat calculated by the suction temperature 2, and the heat pipe electronic expansion valve EEV1 automatically controls the operation according to the superheat calculated by the suction temperature 1. The control system closes the solenoid valve 2 and opens the solenoid valve 1. At this time, it is mixed mode cooling. The two evaporators work at the same time, each running according to the set superheat.

[0038] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0039] 1. The present invention provides two sets of evaporators and both of them work simultaneously in each operation mode, and each operates according to the set superheat. The present invention greatly improves the heat exchange efficiency. The traditional single-evaporator air conditioner has limited heat exchange capacity when facing complex indoor and outdoor environments and various cooling and heating load requirements. The dual evaporator of the present invention can realize indoor and outdoor heat exchange more quickly and efficiently, and accurately adapt to different areas or different working conditions. In large buildings, different room orientations and functions lead to large differences in cooling and heating loads. The dual evaporator can be accurately adjusted according to the actual conditions of each area, and the indoor temperature can be quickly adjusted to the set value, which significantly improves the user's comfort.

[0040] 2. The present invention automatically switches between compressor mode, energy-saving mode and hybrid refrigeration mode according to different temperature scenarios. The air-conditioning system can select the most suitable operation mode according to actual environmental conditions and heat load requirements. In a high-temperature environment, the compressor mode can provide powerful refrigeration capacity and quickly reduce the indoor temperature. In transitional seasons, the energy-saving mode can maintain a comfortable indoor temperature while reducing energy consumption. In an environment with high load and large temperature difference, the hybrid refrigeration mode gives full play to the synergistic effect of the compressor and the fluorine pump to achieve efficient refrigeration and heating. This multi-mode automatic switching mechanism ensures that the system can maintain efficient operation under various working conditions and effectively meet the use requirements in different scenarios.

[0041] 3. The present invention automatically controls the operation by calculating the superheat according to the suction temperature 2 through the compressor electronic expansion valve EEV2, and automatically controls the operation by calculating the superheat according to the suction temperature 1 through the heat pipe electronic expansion valve EEV1. The present invention can accurately adjust the refrigerant flow rate. Traditional air conditioners often have low evaporator working efficiency and energy waste due to improper refrigerant flow control. The present invention can accurately control the superheat so that the evaporator always works in the best state, improves energy utilization efficiency, and reduces operating costs. At the same time, in the automatic mode, it automatically switches between different operating modes according to the preset switching time setting value, can dynamically adjust energy consumption according to actual operating conditions, and automatically switch to energy-saving mode when the indoor heat load is low, thereby reducing the operating time of high-energy-consuming components such as compressors, and effectively improving the energy efficiency ratio (COP) of the whole machine.

[0042] 4. When a key component in the system fails, the present invention can adjust the control strategy through the central control main control board, so that the system can continue to operate in a similar energy-saving mode. When a traditional air conditioner encounters a component failure, it often causes the entire system to shut down, affecting the comfort of the indoor environment. When a failure occurs, the present invention can still maintain the basic indoor refrigeration capacity to a certain extent, ensure the comfort of the indoor environment, and avoid the inconvenience caused by sudden failures. In addition, data is collected through sensors such as suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1, and suction temperature 2, and the data is transmitted to the central control main control board to achieve precise control of each component, and can monitor the operating status of the system in real time, and adjust the operating parameters of components such as the compressor, fluorine pump, and outdoor fan in time to ensure that the system can operate stably under different working conditions, reduce the probability of failures caused by pressure and temperature fluctuations, improve the reliability and stability of the system, and reduce maintenance costs and downtime. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the technical principle of the control method in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0045] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] Please see attached Figure 1 The present invention provides a control method for a fluorine pump heat pipe air conditioner with a dual evaporator, the control method comprising a control system, the control system automatically switches the operation mode according to different temperature scenes, the operation mode comprising a compressor mode, an energy-saving mode and a mixed refrigeration mode, and the control method comprises the following specific steps:

[0047] Step 1: Start preparation, start the control system, and then turn on the indoor EC speed-adjustable fan;

[0048] Step 2: Expansion valve control: for the compressor electronic expansion valve EEV2, according to the suction temperature 2 (T s2 ) and suction pressure 2(P s2 ) Calculate superheat S h2 , the calculation formula is:

[0049] S h2 =T s2 -T sat (P s2)

[0050] Among them, T sat (P s2 ) is based on P s2 Check the value obtained from the refrigerant saturation temperature table to automatically adjust the opening of EEV2. For the heat pipe electronic expansion valve EEV1, according to the suction temperature 1 (T s1 ) and suction pressure 1(P s1 ) Calculate superheat S h1 , T sat (P s1 ) is based on P s1 Check the refrigerant saturation temperature table to obtain the value, and the calculation formula is:

[0051] S h1 =T s1 -T sat (P s1 )

[0052] Automatically control the opening of EEV1;

[0053] Step 3: Determine the operation mode according to different temperature scenarios. In compressor mode, open solenoid valve 1 and close solenoid valve 2. In energy-saving mode, open solenoid valve 2 and close solenoid valve 1. In mixed cooling mode, close solenoid valve 2 and open solenoid valve 1.

[0054] Step 4: Component operation control:

[0055] Compressor mode: Start the compressor and adjust the pressure according to the condensing pressure sensor data P C , adjust the outdoor unit variable frequency fan speed N through the PID control algorithm fan , the formula is:

[0056]

[0057] Among them, P set is the preset condensation pressure threshold, K p is the proportionality coefficient, ∫(P C -P set )dt represents the integral term from the start time to the current time, K i Indicates the integral coefficient, K d is the differential coefficient, dt is the time differential term, and d is the differential operation;

[0058] Energy-saving mode: turn on the outdoor unit fan, fluorine pump and fluorine pump solenoid valve, and adjust the heat pipe EEV1 to the maximum opening;

[0059] Mixed refrigeration mode: turn on the fluorine pump and close the fluorine pump solenoid valve, the heat pipe EEV1 works according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point;

[0060] Step 5: Mode switching. In automatic mode, the energy-saving mode, compressor mode and mixed refrigeration mode are automatically switched according to the preset switching time setting value, so that the system can operate efficiently under different working conditions and improve the energy efficiency ratio of the whole machine.

[0061] In one embodiment of the present invention: in compressor mode, the system opens solenoid valve 1 and closes solenoid valve 2. After starting the compressor, the outdoor unit variable frequency fan speed control output is automatically adjusted according to the pressure detected by the condensing pressure sensor, and the fluorine pump and the fluorine pump solenoid valve are in a closed state.

[0062] In one embodiment of the present invention: in energy-saving mode, the system opens solenoid valve 2, closes solenoid valve 1, turns on the outdoor fan, the fluorine pump and the fluorine pump solenoid valve are turned on and operated, and the heat pipe EEV1 operates at the maximum opening.

[0063] In one embodiment of the present invention: in the mixed refrigeration mode, the system closes the solenoid valve 2, opens the solenoid valve 1, closes the fluorine pump solenoid valve, starts the fluorine pump, the heat pipe EEV1 operates according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point.

[0064] In one embodiment of the present invention: in the automatic mode, the switching between the energy-saving mode, the compressor mode and the mixed refrigeration mode is performed according to the switching time setting value, and the switching steps are as follows:

[0065] S1, first turn on the indoor fan;

[0066] S2, open EEV1 and EEV2 respectively, and control their operation according to the corresponding suction pressure and suction temperature;

[0067] S3, control the opening and closing of solenoid valve 1 and solenoid valve 2 according to different mode requirements;

[0068] S4. Determine the outdoor fan operating speed based on the outdoor temperature and pipeline condensing pressure, and start the corresponding compressor and fluorine pump.

[0069] In one embodiment of the present invention: the control method uses a central control main control board to control various components of the refrigeration system, including sending control instructions to the compressor drive board, various solenoid valves, electronic expansion valves, outdoor fans and fluorine pumps.

[0070] In one embodiment of the present invention: the control method also includes collecting data through suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1 and suction temperature 2 sensors, and transmitting the data to the central control main control board to achieve precise control of each component.

[0071] In one embodiment of the present invention, when the energy-saving mode, the compressor mode and the mixed cooling mode are operated, the blower is always kept on to provide refrigeration circulating air for the room.

[0072] In one embodiment of the present invention: the control method also includes in each operating mode, when it is detected that any parameter among the suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1, and suction temperature 2 exceeds the preset safety threshold, the central control main control board issues an alarm and controls the corresponding components to adjust the operating status or stop operating to ensure the safe and stable operation of the air-conditioning system.

[0073] Example 1, please refer to the attached Figure 1 , compressor mode operation in high temperature environment

[0074] In summer, the outdoor temperature reaches 38℃, the indoor heat load is large, the indoor set temperature is 26℃, and the actual temperature reaches 30℃. After the air conditioning system is started, it enters the compressor mode. After the central control main control board receives the indoor EC speed regulating fan start signal, it starts the fan and sets the fan speed to 1200r / min. The data is obtained through the suction temperature 1 and suction temperature 2 sensors. The suction temperature 1 is 20℃ and the suction temperature 2 is 22℃. At the same time, the pressure value of the refrigerant at the outlet of the corresponding evaporator is obtained through the pressure sensor. According to the pressure value, the pre- The refrigerant thermodynamic property data stored in the controller is queried, and the saturation temperature of the refrigerant corresponding to the suction pressure 1 is 15°C, and the saturation temperature of the refrigerant corresponding to the suction pressure 2 is 17°C. According to the superheat calculation formula: superheat = actual suction temperature - saturation temperature, the superheat 1 controlled by EEV1 corresponding to the heat pipe evaporator is calculated to be = suction temperature 1 - corresponding saturation temperature 1 = 20°C - 15°C = 5°C, and the superheat 2 controlled by EEV2 corresponding to the compressor evaporator is = suction temperature 2 - corresponding saturation temperature 2 = 22°C - 17°C = 5°C;

[0075] The calculated superheat is compared with the preset superheat value (set to 5°C), and the opening of the heat pipe electronic expansion valve EEV1 and the compressor electronic expansion valve EEV2 are automatically adjusted according to the comparison results. When the actual superheat is greater than the preset superheat, it means that the refrigerant in the evaporator is fully evaporated and the refrigerant flow rate may be too small. At this time, the central control main control board will issue an instruction to appropriately increase the opening of the electronic expansion valve (EEV1 or EEV2) to allow more refrigerant to enter the evaporator. If the actual superheat is less than the preset superheat, it means that the refrigerant in the evaporator may not be completely evaporated and the refrigerant flow rate is too large. The main control board controls the electronic expansion valve to reduce the opening and reduce the refrigerant flow rate, so as to ensure that the evaporator operates stably under the set superheat.

[0076] At this time, the system opens solenoid valve 1, closes solenoid valve 2, starts the compressor, and the condensing pressure sensor monitors the pressure in real time. The condensing pressure is 1.8MPa. The main control board automatically adjusts the speed of the outdoor unit variable frequency fan to 1500r / min according to the pressure to speed up heat dissipation. The two sets of evaporators work efficiently at the same time, each operating according to the set superheat to quickly reduce the indoor temperature.

[0077] Example 2, please refer to the attached Figure 1 , energy-saving mode operation during transition seasons

[0078] In the transitional season of spring and autumn, the outdoor temperature is around 20℃, and there is only slight heat accumulation indoors. The actual indoor temperature is 24℃, and the set temperature is 25℃. The system starts the energy-saving mode, and the indoor EC speed-regulating fan is turned on. The fan speed is set to 800r / min. EEV1 and EEV2 calculate the superheat according to the suction temperature 1 and the suction temperature 2 respectively and automatically control the opening. The suction temperature 1 is 18℃, and the suction temperature 2 is 19℃. After obtaining the corresponding pressure value through the pressure sensor, it is found that the corresponding saturation temperature 1 is 14℃, and the saturation temperature 2 is 15℃. The superheat is calculated, and the superheat 1 = 18℃-14℃ = 4℃, the superheat 2 = 19℃-15℃ = 4℃, and the superheat is set to 4℃. Among them, the heat pipe EEV1 operates at the maximum opening, and the maximum opening is set to 80%;

[0079] The system opens solenoid valve 2, closes solenoid valve 1, turns on the outdoor unit fan, fluorine pump and fluorine pump solenoid valve, sets the fan speed to 1000r / min, and the fluorine pump drives the refrigerant circulation to absorb indoor heat through two sets of evaporators, maintaining a comfortable indoor temperature with lower energy consumption.

[0080] Example 3, please refer to the attached Figure 1 , Hybrid cooling mode operation under high load and large temperature difference environment (large data center)

[0081] The equipment in some areas generates a lot of heat. The actual indoor temperature reaches 35℃, the set temperature is 22℃, and the temperature difference between indoor and outdoor is large. The outdoor temperature is 15℃. The system adopts mixed cooling mode. After the indoor EC speed-regulating fan is turned on, the fan speed is set to 1500r / min. EEV1 and EEV2 automatically adjust the opening according to the suction temperature and pressure. The suction temperature 1 is 25℃, and the suction temperature 2 is 27℃. The corresponding saturation temperature 1 is 19℃, the saturation temperature 2 is 21℃, and the superheat is set to 6℃. It is calculated that superheat 1 = 25℃-19℃ = 6℃, superheat 2 = 27℃-21℃ = 6℃. The system closes solenoid valve 2, opens solenoid valve 1, starts the compressor and fluorine pump, the fluorine pump solenoid valve is closed, the compressor and fluorine pump work together, and the two sets of evaporators run at full capacity. They efficiently cool according to the superheat set by each, quickly take away the indoor heat, and meet the high requirements of the data center for temperature control.

[0082] Example 4, please refer to the attached Figure 1 , automatic mode switching process (energy saving mode to compressor mode)

[0083] At night, the outdoor temperature gradually decreases, and the air conditioning system initially operates in energy-saving mode. As the indoor heat load increases, the indoor temperature rises from 25°C to 28°C, reaching the preset mode switching time setting value, which is set to switch after 30 minutes of operation;

[0084] The central control main control board issues a command to first keep the indoor EC speed-adjustable fan running, and the fan speed is increased from 800r / min to 1000r / min. Then the control mode of EEV1 and EEV2 is adjusted. EEV1 switches from the maximum opening to the operation based on the superheat calculated according to the suction temperature 1 and the suction pressure 1. The suction temperature 1 is 20℃, the saturation temperature corresponding to the suction pressure 1 is 15℃, and the superheat is set to 5℃. The calculation shows that superheat 1 = 20℃-15℃ = 5℃. EEV2 continues to operate according to the suction temperature 2 and the suction pressure 1. Force 2 runs automatically, the suction temperature 2 is 22℃, the saturation temperature corresponding to the suction pressure 2 is 17℃, and the superheat is also set to 5℃. It is calculated that superheat 2 = 22℃-17℃ = 5℃, then close solenoid valve 2, open solenoid valve 1, close the fluorine pump and the fluorine pump solenoid valve, start the compressor, and adjust the speed of the outdoor unit variable frequency fan according to the condensing pressure. The condensing pressure is 1.5MPa, and the speed of the outdoor unit variable frequency fan is adjusted to 1200r / min, completing the switch from energy-saving mode to compressor mode to ensure stable indoor cooling effect.

[0085] Example 5, please refer to the attached Figure 1 , automatic mode switching process (compressor mode to mixed cooling mode)

[0086] During the day, the air conditioning system first operates in compressor mode. When the indoor and outdoor temperatures and heat load change, the indoor temperature rises from 26°C to 29°C, and the outdoor temperature rises from 25°C to 28°C, the mode switching condition is triggered. The setting value is to switch when the indoor temperature is higher than 28°C and the outdoor temperature is higher than 25°C.

[0087] The central control main control panel controls the EC speed regulating fan in the room to work continuously, and the fan speed increases from 1200r / min to 1300r / min, maintaining the automatic control mode of EEV1 and EEV2. The suction temperature 1 is 22℃, and the corresponding saturation temperature is 17℃. The suction temperature 2 is 24℃, and the corresponding saturation temperature is 19℃. The superheat is set to 5℃. It is calculated that superheat 1 = 22℃-17℃ = 5℃, and superheat 2 = 24℃-19℃ = 5℃.

[0088] Close solenoid valve 1, open solenoid valve 2, start the fluorine pump, keep the compressor running, close the fluorine pump solenoid valve, and adjust the speed of the outdoor unit variable frequency fan according to the outdoor temperature and condensing pressure. The condensing pressure is 1.6MPa, and the speed of the outdoor unit variable frequency fan is adjusted to 1400r / min to achieve a smooth switch from compressor mode to mixed cooling mode and improve the system cooling efficiency.

[0089] Example 6, please refer to the attached Figure 1 , emergency operation in case of failure

[0090] During operation, if the compressor fails, the system detects that the compressor current increases abnormally and exceeds 1.5 times the rated current. After the central control main control board detects the relevant fault signal, if it is currently in compressor mode or mixed cooling mode, it will immediately make adjustments;

[0091] Turn off the compressor and related control circuits, adjust the control strategy, open solenoid valve 2, close solenoid valve 1, adjust the heat pipe EEV1 to the maximum opening, and EEV2 continues to automatically control according to the suction temperature 2 and the suction pressure 2. The suction temperature 2 is 20°C, the saturation temperature corresponding to the suction pressure 2 is 16°C, and the superheat is set to 4°C. It is calculated that superheat 2 = 20°C - 16°C = 4°C;

[0092] Start the fluorine pump and the fluorine pump solenoid valve, keep the outdoor unit fan running, set the fan speed to 1100r / min, and allow the system to continue running in a similar energy-saving mode. When the compressor fails, it can still provide a certain cooling capacity for the room, ensure the basic comfort of the indoor environment, and wait for maintenance personnel to handle it.

[0093] Embodiment 7, please refer to the attached Figure 1 , mode and component working status description

[0094] 1. In the compressor cooling mode, the compressor EEV2 operates according to its set superheat, and the heat pipe EEV1 works at the same time, and it operates according to the superheat set by the heat pipe EEV1;

[0095] 2. In energy-saving mode, the heat pipe EEV1 operates at the maximum opening, and the compressor EEV2 works at the same time, and it operates according to the superheat set by the compressor EEV2;

[0096] 3. In the mixed cooling mode, the heat pipe EEV1 works according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point.

[0097]

[0098] Embodiment 8, please refer to the attached Figure 1In automatic mode, the switching between the energy-saving mode, compressor mode and mixed cooling mode is carried out according to the switching time setting value, as shown in the following table:

[0099]

[0100]

[0101] According to the above embodiments, it can be concluded that by setting up dual evaporators and making them work simultaneously according to the set superheat, automatically switching multiple modes, accurately controlling the refrigerant flow, and intelligent fault response and precise component control, the cooling and heating efficiency of the air conditioner is effectively improved, energy consumption is reduced, and the system stability and reliability are enhanced. In addition, by closely cooperating with each control link, the air conditioner usage requirements in different scenarios can be met. The present invention has significant technical advantages and broad application prospects.

[0102] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A control method for a fluorine pump heat pipe air conditioner with dual evaporators, the control method comprising a control system, the control system automatically switches the operation mode according to different temperature scenes, the operation mode comprising a compressor mode, an energy-saving mode and a mixed refrigeration mode, characterized in that: The specific steps of the control method are as follows: Step 1: Start preparation, start the control system, and then turn on the indoor EC speed-adjustable fan; Step 2: Expansion valve control: for the compressor electronic expansion valve EEV2, according to the suction temperature 2 (T s2 ) and suction pressure 2(P s2 ) Calculate superheat S h2 , the calculation formula is: S h2 =T s2 -T sat (P s2 ) Among them, T sat (P s2 ) is based on P s2 Check the value obtained from the refrigerant saturation temperature table to automatically adjust the opening of EEV2. For the heat pipe electronic expansion valve EEV1, according to the suction temperature 1 (T s1 ) and suction pressure 1(P s1 ) Calculate superheat S h1 , T sat (P s1 ) is based on P s1 Check the refrigerant saturation temperature table to obtain the value, and the calculation formula is: S h1 =T s1 -T sat (P s1 ) Automatically control the opening of EEV1; Step 3: Determine the operation mode according to different temperature scenarios. In compressor mode, open solenoid valve 1 and close solenoid valve 2. In energy-saving mode, open solenoid valve 2 and close solenoid valve 1. In mixed cooling mode, close solenoid valve 2 and open solenoid valve 1. Step 4: Component operation control: Compressor mode: Start the compressor and adjust the pressure according to the condensing pressure sensor data P C , adjust the outdoor unit variable frequency fan speed N through the PID control algorithm fan , the formula is: Among them, P set is the preset condensation pressure threshold, K p is the proportionality coefficient, ∫(P C -P set )dt represents the integral term from the start time to the current time, K i Indicates the integral coefficient, K d is the differential coefficient, dt is the time differential term, and d is the differential operation; Energy-saving mode: turn on the outdoor unit fan, fluorine pump and fluorine pump solenoid valve, and adjust the heat pipe EEV1 to the maximum opening; Mixed refrigeration mode: turn on the fluorine pump and close the fluorine pump solenoid valve, the heat pipe EEV1 works according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point; Step 5: Mode switching. In automatic mode, the energy-saving mode, compressor mode and mixed cooling mode are automatically switched according to the preset switching time setting value.

2. The control method of a fluorine pump heat pipe air conditioner with double evaporators according to claim 1, characterized in that: In the compressor mode, the system opens solenoid valve 1 and closes solenoid valve 2. After starting the compressor, the outdoor unit variable frequency fan speed control output is automatically adjusted according to the pressure detected by the condensing pressure sensor, and the fluorine pump and the fluorine pump solenoid valve are in the closed state.

3. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: In the energy-saving mode, the system opens solenoid valve 2, closes solenoid valve 1, turns on the outdoor fan, the fluorine pump and the fluorine pump solenoid valve are turned on and operated, and the heat pipe EEV1 operates at the maximum opening.

4. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: In the mixed refrigeration mode, the system closes solenoid valve 2, opens solenoid valve 1, closes the fluorine pump solenoid valve, starts running the fluorine pump, the heat pipe EEV1 operates according to the set superheat, and the compressor EEV2 operates according to the compression superheat set point.

5. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: In the automatic mode, the switching between the energy-saving mode, the compressor mode and the mixed cooling mode is performed according to the switching time setting value, and the switching steps are as follows: S1, first turn on the indoor fan; S2, open EEV1 and EEV2 respectively, and control their operation according to the corresponding suction pressure and suction temperature; S3, control the opening and closing of solenoid valve 1 and solenoid valve 2 according to different mode requirements; S4. Determine the outdoor fan operating speed based on the outdoor temperature and pipeline condensing pressure, and start the corresponding compressor and fluorine pump.

6. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: The control method uses a central control main control board to control various components of the refrigeration system, including sending control instructions to the compressor drive board, various solenoid valves, electronic expansion valves, outdoor fans and fluorine pumps.

7. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: The control method further includes collecting data through suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1 and suction temperature 2 sensors, and transmitting the data to a central control main control board.

8. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: When the energy-saving mode, compressor mode and mixed cooling mode are in operation, the air supply fan is always kept on to provide refrigeration circulating air for the room.

9. The control method of a fluorine pump heat pipe air conditioner with dual evaporators according to claim 1, characterized in that: The control method also includes in each operating mode, when it is detected that any parameter among the suction pressure 1, suction pressure 2, condensing pressure, suction temperature 1, and suction temperature 2 exceeds the preset safety threshold, the central control main control board issues an alarm and controls the corresponding components to adjust the operating status.

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