Air source heat pump control system and control method thereof

Abstract

The present invention discloses an air source heat pump control system and a control method thereof. The air source heat pump control system comprises: a heat pump device, a first temperature sensor, a second temperature sensor and a controller. By setting the first temperature sensor and the second temperature sensor, the first temperature sensor is arranged in a water inlet to detect a water inlet temperature #imgabs0#, and the second temperature sensor is suitable for detecting an ambient temperature #imgabs1#. The controller controls the operating frequency #imgabs4# of the compressor, as well as the opening degree #imgabs5# of the first expansion valve and the opening degree #imgabs6# of the second expansion valve in real time according to the received water inlet temperature #imgabs2# and the ambient temperature #imgabs3#, so that the compressor can stably operate at an adapted frequency while meeting load requirements, and by adjusting the opening degree #imgabs7# of the first expansion valve and the opening degree #imgabs8# of the second expansion valve, it is ensured that the heat pump device outputs optimal heat, so as to increase the system circulation flow, thereby improving energy efficiency, and at the same time reducing the system exhaust temperature to ensure stable operation of the unit.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump systems, and in particular to an air source heat pump control system and a control method thereof. Background Art

[0002] A heat pump is a highly efficient energy-saving device that makes full use of low-grade thermal energy. It converts low-grade heat sources into high-grade heat sources using a reverse Carnot cycle. It consumes only a small amount of reverse cycle net work to obtain a large amount of heating, effectively utilizing low-grade thermal energy that is difficult to use to achieve energy-saving purposes.

[0003] When heat pumps are used in areas with low ambient temperatures, the heating effect is poor and the heating effect cannot be achieved. In areas with high ambient temperatures, the cooling effect of heat pumps is poor and cooling in high temperature environments cannot be achieved. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art that the heat pump has poor heating and / or cooling effects and cannot operate stably when applied to a high or low temperature environment, thereby providing an air source heat pump control system and a control method thereof.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0006] An air source heat pump control system, comprising: a heat pump device, a first temperature sensor, a second temperature sensor and a controller; the heat pump device comprises a compressor, a first heat exchanger and a second heat exchanger, and a first expansion valve and a second expansion valve arranged in series, the first expansion valve and the second expansion valve are arranged between the first heat exchanger and the second heat exchanger, the first heat exchanger is connected to an external heat device through a water supply pipeline, the first heat exchanger is provided with a water inlet and a water outlet; the first temperature sensor is arranged in the water inlet, so as to be suitable for detecting the inlet water temperature ; The second temperature sensor is suitable for detecting the ambient temperature The compressor, the first expansion valve, the second expansion valve, the first temperature sensor and the second temperature sensor are all connected to the controller in communication, and the controller is suitable for receiving the water inlet temperature and the ambient temperature , to control the operating frequency of the compressor , and controlling the opening of the first expansion valve and the opening degree of the second expansion valve .

[0007] According to some embodiments of the present invention, the air source heat pump control system further comprises a third temperature sensor, which is arranged in the water outlet to detect the outlet water temperature. The controller is preset with a target water outlet temperature threshold And the differential temperature The controller is adapted to receive the outlet water temperature , and according to the formula: , to control the compressor to start or stop.

[0008] According to some embodiments of the present invention, the heat pump device has a heating mode and a cooling mode. In the heating mode: the return temperature The value is positive; in cooling mode, the return temperature The value is negative.

[0009] According to some embodiments of the present invention, the heat pump device further comprises a vaporization device, the first expansion valve is disposed between the first heat exchanger and the vaporization device, and the second expansion valve is disposed between the vaporization device and the second heat exchanger;

[0010] In the heating mode: the heat exchange medium flows out of the compressor, flows through the first heat exchanger, the first expansion valve, the vaporizer, the second expansion valve and the second heat exchanger in sequence, and flows back into the compressor to form a first heating circuit; and flows through the first heat exchanger, the first expansion valve and the vaporizer in sequence, and flows back into the compressor to form a second heating circuit;

[0011] In the refrigeration mode: the heat exchange medium flows out through the compressor, flows through the second heat exchanger, the second expansion valve, the vaporizer, the first expansion valve and the first heat exchanger, and flows back to the compressor to form a first refrigeration circuit; and flows through the second heat exchanger, the second expansion valve and the vaporizer, and flows back to the compressor to form a second refrigeration circuit.

[0012] According to some embodiments of the present invention, the heat pump device further comprises a reversing valve body communicatively connected to the controller, the reversing valve body comprising a first valve port, a second valve port, a third valve port and a fourth valve port, the first valve port being communicated with a discharge port of the compressor, the second valve port being communicated with the first heat exchanger, the third valve port being communicated with a first return port of the compressor, and the fourth valve port being communicated with the second heat exchanger;

[0013] In the heating mode, the first valve port is communicated with the second valve port, and the third valve port is communicated with the fourth valve port; in the cooling mode, the first valve port is communicated with the fourth valve port, and the second valve port is communicated with the third valve port.

[0014] According to some embodiments of the present invention, the heat pump device also includes a one-way valve and a capillary tube, the one-way valve and the capillary tube are arranged in series, and the one-way valve, the capillary tube and the first expansion valve are arranged in parallel to form a first throttling group, the one-way valve and the first expansion valve are connected to the port close to the first heat exchanger through the capillary tube, and the valve direction of the one-way valve is set in the direction of flow from the second heat exchanger to the first heat exchanger.

[0015] According to some embodiments of the present invention, a fourth temperature sensor is provided on the connecting pipeline between the first valve port and the exhaust port of the compressor, and the fourth temperature sensor is suitable for detecting the exhaust temperature of the compressor. A fifth temperature sensor is provided on the connecting pipe between the third valve port and the compressor, and the second temperature sensor is suitable for detecting the suction temperature of the compressor The second heat exchanger is provided with a sixth temperature sensor, the sixth temperature sensor is suitable for detecting the coil temperature in the second heat exchanger ;

[0016] The fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor are all in communication with the controller, and the controller is adapted to receive the exhaust temperature , Intake temperature and coil temperature ; to control the regulation speed of the first expansion valve and the regulation speed of the second expansion valve.

[0017] According to some embodiments of the present invention, the operating frequency of the compressor , the opening degree of the first expansion valve and the opening degree of the second expansion valve Both are consistent with the inlet water temperature A linear function relationship; and / or

[0018] The operating frequency of the compressor , the opening degree of the first expansion valve and the opening degree of the second expansion valve The ambient temperature A linear function relationship.

[0019] The present invention provides a control method for an air source heat pump control system, comprising the following steps:

[0020] Output cooling mode or heating mode command, the controller receives the water outlet temperature , and according to the formula: , to control the compressor to start in cooling mode or heating mode;

[0021] The controller receives the ambient temperature and initial water inlet temperature , based on the set frequency simulation table, the first expansion valve opening simulation table and the second expansion valve opening simulation table, calculate the ambient temperature The initial water inlet temperature The corresponding operating frequency of the compressor , and calculating the opening degree of the first expansion valve and the opening degree of the second expansion valve ;

[0022] The controller receives the real-time inlet water temperature , and based on the set frequency simulation table, the first expansion valve opening simulation table and the second expansion valve opening simulation table, the controller controls the ambient temperature in real time The real-time inlet water temperature The corresponding operating frequency of the compressor , and calculating the opening degree of the first expansion valve and the opening degree of the second expansion valve .

[0023] According to some embodiments of the present invention, the controller receives the suction temperature in real time and coil temperature The controller is provided with a target suction temperature And the first hysteresis threshold, the controller according to the formula:

[0024]

[0025] Get , when the The absolute value of the first hysteresis threshold is greater than the first hysteresis threshold, the controller controls the first expansion valve to accelerate the adjustment. The absolute value of is less than the first hysteresis threshold, the controller controls the first expansion valve to slow down and adjust; is a positive value, the controller controls the valve step of the first expansion valve to increase, and the is a negative value, the controller controls the valve step of the first expansion valve to decrease;

[0026] The controller receives the exhaust temperature in real time and outlet water temperature , the controller is provided with a target exhaust temperature And the second hysteresis threshold, according to the formula:

[0027]

[0028] Where ε is a constant, the controller calculates ; When the The absolute value of the second hysteresis threshold is greater than the second hysteresis threshold, the controller controls the second expansion valve to accelerate the adjustment. The absolute value of is less than the second hysteresis threshold, the controller controls the second expansion valve to decelerate and adjust; is a positive value, the controller controls the valve step of the second expansion valve to increase, and the is a negative value, the controller controls the valve step of the second expansion valve to decrease.

[0029] According to some embodiments of the present invention, the exhaust gas superheat parameter is set by the controller. and , set time parameters and , and set the regulating valve step parameters of the second expansion valve and , the heat pump equipment is initially started and the controller detects the exhaust temperature ;

[0030] when The controller controls the second expansion valve at a time parameter Internal regulating valve step ;

[0031] when When the controller controls the second expansion valve to Internal regulating valve step ;

[0032] when When the controller obtains After comparison with the set second hysteresis threshold, the valve step adjustment of the second expansion valve is controlled.

[0033] According to some embodiments of the present invention, the first expansion valve is regulated by PID control, and the controller sets a parameter for regulating the number of oscillations. And temperature range parameters and ,in Greater than ;

[0034] The controller calculates and obtains ,when as well as When the actual number of adjustment oscillations exceeds the number of adjustment oscillations parameter The controller performs transition control. During transition control, the proportional coefficient in the PID control adjustment Halved.

[0035] The technical solution of the present invention has the following advantages:

[0036] 1. The air source heat pump control system provided by the present invention is provided with a first temperature sensor and a second temperature sensor. The first temperature sensor is provided in the water inlet to detect the water inlet temperature. , the second temperature sensor is suitable for detecting the ambient temperature The controller receives the water inlet temperature and ambient temperature , real-time control of the compressor operating frequency , and the opening degree of the first expansion valve and the opening of the second expansion valve , so that the compressor can run stably at an adaptive frequency while meeting the load demand, and the opening of the first expansion valve is adjusted and the opening of the second expansion valve , to ensure that the heat pump equipment outputs optimal heat, to increase the system circulation flow, thereby improving energy efficiency, while reducing the system exhaust temperature to ensure stable operation of the unit.

[0037] 2. The control method of the air source heat pump control system provided by the present invention, the controller is based on the outlet water temperature Control the start of the compressor cooling mode or heating mode, and control the operating frequency of the compressor in real time based on the set frequency simulation table, the first expansion valve opening simulation table and the second expansion valve opening simulation table , and calculating the opening degree of the first expansion valve and the opening degree of the second expansion valve , so that the operating frequency of the compressor , the opening of the first expansion valve and the opening of the second expansion valve Matching the operating conditions of the heat pump equipment, the compressor can operate stably at an adapted frequency while meeting the load demand, ensuring that the heat pump equipment outputs optimal heat to increase the system circulation flow, thereby improving energy efficiency, while reducing the system exhaust temperature to ensure stable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1A schematic diagram of a heat pump device in a heating mode provided in some embodiments of the present invention;

[0040] Figure 2 A schematic diagram of a heat pump device in a cooling mode provided in some embodiments of the present invention;

[0041] Figure 3 It is a schematic diagram of the structure of a vaporization device provided in some embodiments of the present invention;

[0042] Figure 4 It is a structural schematic diagram of a reversing valve body provided in some embodiments of the present invention;

[0043] Figure 5 This is a flow chart of a control method of an air source heat pump control system provided in some embodiments of the present invention.

[0044] Explanation of the reference numerals: 1. compressor; 2. first heat exchanger; 3. second heat exchanger; 4. vaporization device; 5. first throttling group; 6. second throttling group; 7. reversing valve body; 8. fan; 41. first port; 42. second port; 43. third port; 51. first expansion valve; 52. one-way valve; 53. capillary tube; 61. second expansion valve; 62. filter; 71. first valve port; 72. second valve port; 73. third valve port; 74. fourth valve port. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Reference Figures 1 to 5 As shown, in some embodiments of the present invention, an air source heat pump control system is provided, comprising: a heat pump device, a first temperature sensor, a second temperature sensor and a controller; the heat pump device comprises a compressor 1, a first heat exchanger 2 and a second heat exchanger 3, and a first expansion valve 51 and a second expansion valve 61 arranged in series, the first expansion valve 51 and the second expansion valve 61 are arranged between the first heat exchanger 2 and the second heat exchanger 3, the first heat exchanger 2 is connected to an external heat device through a water supply pipeline, and the first heat exchanger 2 is provided with a water inlet and a water outlet; the first temperature sensor is arranged in the water inlet to detect the inlet water temperature ; The second temperature sensor is suitable for detecting the ambient temperature The compressor 1, the first expansion valve 51, the second expansion valve 61, the first temperature sensor and the second temperature sensor are all connected to the controller for communication, and the controller is adapted to receive the water inlet temperature and ambient temperature , to control the operating frequency of compressor 1 , and controlling the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 .

[0050] Specifically, a first temperature sensor and a second temperature sensor are provided, wherein the first temperature sensor is provided in the water inlet to detect the water inlet temperature. , the second temperature sensor is suitable for detecting the ambient temperature , the controller receives the water inlet temperature and ambient temperature , real-time control of the operating frequency of compressor 1 , and the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 , so that the compressor 1 can run stably at an adapted frequency while meeting the load demand, and the opening of the first expansion valve 51 can be adjusted. and the opening degree of the second expansion valve 61 , to ensure that the heat pump equipment outputs optimal heat, to increase the system circulation flow, thereby improving energy efficiency, while reducing the system exhaust temperature to ensure stable operation of the unit.

[0051] In some embodiments of the present invention, the air source heat pump control system further includes a third temperature sensor, which is arranged in the water outlet to detect the outlet water temperature. , the controller has a preset target water outlet temperature threshold And the differential temperature , the controller is adapted to receive the outlet water temperature , and according to the formula: , to control compressor 1 to start or stop.

[0052] In some embodiments of the present invention, the heat pump device has a heating mode and a cooling mode. In the heating mode, the return temperature The value is positive; in cooling mode, the return temperature The value is negative.

[0053] Reference Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments of the present invention, the heat pump device further includes a vaporization device 4, a first expansion valve 51 is disposed between the first heat exchanger 2 and the vaporization device 4, and a second expansion valve 61 is disposed between the vaporization device 4 and the second heat exchanger 3;

[0054] In the heating mode: the heat exchange medium flows out through the compressor 1, flows through the first heat exchanger 2, the first expansion valve 51, the vaporizer 4, the second expansion valve 61 and the second heat exchanger 3 in sequence, and flows back into the compressor 1 to form a first heating circuit; and flows through the first heat exchanger 2, the first expansion valve 51 and the vaporizer 4 in sequence, and flows back into the compressor 1 to form a second heating circuit;

[0055] In the refrigeration mode: the heat exchange medium flows out through the compressor 1, flows through the second heat exchanger 3, the second expansion valve 61, the vaporizer 4, the first expansion valve 51 and the first heat exchanger 2, and flows back to the compressor 1 to form a first refrigeration circuit; and flows through the second heat exchanger 3, the second expansion valve 61 and the vaporizer 4, and flows back to the compressor 1 to form a second refrigeration circuit.

[0056] Specifically, in the heating mode, the heat exchange medium passes through the first throttling group 5 for a first throttling, enters the vaporizing device 4 to achieve gas-liquid separation, the liquid heat exchange medium passes through the second throttling group 6 for a second throttling, enters the second heat exchanger 3 for heat exchange, and then flows back to the compressor 1 to form a first heating circuit, and the gaseous heat exchange medium flows back directly from the vaporizing device 4 to the compressor 1; in the cooling mode, the heat exchange medium flows through the second heat exchanger 3, realizes the first throttling in the first throttling group 5, enters the vaporizing device 4 to achieve gas-liquid separation, the liquid heat exchange medium enters the first heat exchanger 2 for heat exchange after the second throttling in the second throttling group 6, and then flows back to the compressor 1 to form a first cooling circuit, and the gaseous heat exchange medium flows back directly from the vaporizing device 4 to the compressor 1 to form a second cooling circuit. By setting the second heating circuit and the second cooling circuit, the gaseous heat exchange medium flows back to the medium pressure chamber of the compressor 1, reducing the system operation compression ratio, thereby increasing the system circulation flow, improving energy efficiency, and reducing the system exhaust temperature to ensure stable operation of the unit. While realizing secondary throttling, two-stage compression is achieved through the principle of air supplement and enthalpy increase, thereby improving the efficiency of compressor 1 to ensure efficient heating and cooling capabilities in high or low temperature environments, allowing the heat pump system to operate stably.

[0057] It can be understood that the working principle of air replenishment and enthalpy increase is to inhale a part of the intermediate pressure gas during the operation of the compressor 1, mix it with the partially compressed heat exchange medium and then compress it to achieve two-stage compression, thereby improving the efficiency of the compressor 1.

[0058] Reference Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments of the present invention, the vaporizer 4 includes a first port 41, a second port 42 and a third port 43, the first port 41 is arranged on the side wall of the vaporizer 4, the second port 42 is arranged at the bottom of the vaporizer 4, the third port 43 is arranged at the top of the vaporizer 4, the first port 41 is connected to the first throttling group 5, the second port 42 is connected to the second throttling group 6, and the third port 43 is connected to the compressor 1.

[0059] Specifically, the vaporizer 4 is a flash evaporator. The heat exchange medium after throttling by the first throttling group 5 or the second throttling group 6 flashes in the vaporizer 4 to separate the heat exchange medium in saturated gaseous state and saturated liquid state. The third port 43 is connected to the compressor 1. The saturated gaseous heat exchange medium flows back to the medium-pressure chamber of the compressor 1 through the third port 43, thereby reducing the system operation compression ratio, thereby increasing the system circulation flow, improving energy efficiency, and reducing the system exhaust temperature at the same time, ensuring stable operation of the unit.

[0060] Reference Figure 4As shown, in some embodiments of the present invention, the heat pump device further includes a reversing valve body 7 that is communicatively connected to the controller, the reversing valve body 7 includes a first valve port 71, a second valve port 72, a third valve port 73 and a fourth valve port 74, the first valve port 71 is communicated with the discharge port of the compressor 1, the second valve port 72 is communicated with the first heat exchanger 2, the third valve port 73 is communicated with the first reflux port of the compressor 1, and the fourth valve port 74 is communicated with the second heat exchanger 3;

[0061] In the heating mode, the first valve port 71 is connected to the second valve port 72 , and the third valve port 73 is connected to the fourth valve port 74 ; in the cooling mode, the first valve port 71 is connected to the fourth valve port 74 , and the second valve port 72 is connected to the third valve port 73 .

[0062] Specifically, the reversing valve body 7 is an electric four-way reversing valve, and the valve port of the reversing valve body 7 is switched by a controller to achieve switching between the cooling mode and the heating mode.

[0063] In some embodiments of the present invention, the heat pump device also includes a one-way valve 52 and a capillary tube 53. The one-way valve 52 and the capillary tube 53 are arranged in series, and the one-way valve 52, the capillary tube 53 and the first expansion valve 51 are arranged in parallel to form a first throttling group 5. The one-way valve 52 and the first expansion valve 51 are connected to the port close to the first heat exchanger 2 through the capillary tube 53, and the valve direction of the one-way valve 52 is set in the direction of flow from the second heat exchanger 3 to the first heat exchanger 2.

[0064] In some embodiments of the present invention, after the heat exchange medium passes through the first throttling group 5 and enters the vaporizing device 4 from the first port 41, the heat exchange medium forms a saturated gas state and a saturated liquid state in the vaporizing device 4, and the saturated gaseous heat exchange medium flows back to the compressor 1 through the third port 43 to form a first heating loop, and the saturated liquid heat exchange medium flows out through the second port 42, flows through the second throttling group 6 and the second heat exchanger 3, and flows back to the compressor 1 to form a second heating loop;

[0065] After the heat exchange medium passes through the second heat exchanger 3 and the second throttling group 6 and enters the vaporizing device 4 from the second port 42, the heat exchange medium forms a saturated gas and a saturated liquid in the vaporizing device 4. The saturated gaseous heat exchange medium flows back to the compressor 1 through the third port 43 to form a first refrigeration circuit. The saturated liquid heat exchange medium flows through the second port 42, the first throttling group 5 and the first heat exchanger 2, and flows back to the compressor 1 to form a second refrigeration circuit.

[0066] In some embodiments of the present invention, the second throttling group 6 includes a second expansion valve 61 and a filter 62 which are arranged in series, and the filter 62 is located between the second heat exchanger 3 and the second expansion valve 61 .

[0067] Specifically, the first expansion valve 51 is used as the primary throttling in the heating mode. To ensure the stable operation of the unit at -35°C, a small-flow electronic expansion valve is used. However, in cooling, the first expansion valve 51 is used as the secondary throttling. To increase the system evaporation temperature and the cooling capacity, a one-way valve 52 is connected in parallel. The one-way valve 52 is connected to the port of the first expansion valve 51 close to the heat exchanger through a capillary 53, and the valve direction of the one-way valve 52 is set from the second heat exchanger 3 to the first heat exchanger 2, so as to increase the system flow in the cooling mode and ensure the stable operation of the system.

[0068] In some embodiments of the present invention, the heat pump system further comprises a fan 8, which is arranged opposite to the second heat exchanger 3. In the heating circuit, the fan 8 is in an on state.

[0069] Specifically, in the cooling mode, the fan 8 is started to cool the heat exchange medium, and in the heating mode, the fan 8 is started to absorb heat from the air for the heat exchange medium, while avoiding frosting of the second heat exchanger 3 and improving the defrosting efficiency.

[0070] In some embodiments of the present invention, the first heat exchanger 2 is a condenser, the second heat exchanger 3 is an evaporator, and one end of the first heat exchanger 2 is connected to an external heat-using device through a water supply pipe.

[0071] In some embodiments of the present invention, the first heat exchanger 2 is a plate heat exchanger and / or the second heat exchanger 3 is a fin heat exchanger.

[0072] In some embodiments of the present invention, a fourth temperature sensor is provided on the connecting pipe between the first valve port 71 and the exhaust port of the compressor 1, and the fourth temperature sensor is suitable for detecting the exhaust temperature of the compressor 1. A fifth temperature sensor is provided on the connecting pipe between the third valve port 73 and the compressor 1, and the second temperature sensor is suitable for detecting the suction temperature of the compressor 1 The second heat exchanger 3 is provided with a sixth temperature sensor, which is suitable for detecting the coil temperature in the second heat exchanger 3 ;

[0073] The fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor are all connected to the controller, and the controller is adapted to receive the exhaust temperature , Intake temperature and coil temperature ; To control the adjustment speed of the first expansion valve 51 and the adjustment speed of the second expansion valve 61.

[0074] In some embodiments of the present invention, the operating frequency of the compressor 1 is , the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 Inlet water temperature A linear function relationship; and / or

[0075] Operating frequency of compressor 1 , the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 Both with ambient temperature A linear function relationship.

[0076] Specifically, the frequency simulation table, the opening simulation table of the first expansion valve 51, and the opening simulation table of the second expansion valve 61 are set according to the characteristics of the heat pump device and the determined linear function relationship. The specific settings of the frequency simulation table, the opening simulation table of the first expansion valve 51, and the opening simulation table of the second expansion valve 61 are related to the type of the selected compressor 1, the type of the first expansion valve 51, and the type of the second expansion valve 61, and the specific values ​​are not intended to limit the present invention.

[0077] Reference Figure 5 As shown, the present invention provides a control method for an air source heat pump control system, comprising the following steps:

[0078] Output cooling mode or heating mode command, the controller receives the outlet water temperature , and according to the formula: , to control compressor 1 to start in cooling mode or heating mode;

[0079] Controller receives ambient temperature and initial water inlet temperature Based on the set frequency simulation table, the opening degree simulation table of the first expansion valve 51 and the opening degree simulation table of the second expansion valve 61, the calculation is performed at the ambient temperature. Initial water inlet temperature The corresponding operating frequency of compressor 1 , and calculate the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 ;

[0080] The controller receives the real-time inlet water temperature Based on the set frequency simulation table, the opening degree simulation table of the first expansion valve 51 and the opening degree simulation table of the second expansion valve 61, the controller controls the ambient temperature in real time. Real-time water inlet temperature The corresponding operating frequency of compressor 1 , and calculate the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 .

[0081] Specifically, the controller uses the outlet water temperature Control the start of the cooling mode or heating mode of the compressor 1, and control the operating frequency of the compressor 1 in real time based on the set frequency simulation table, the opening simulation table of the first expansion valve 51 and the opening simulation table of the second expansion valve 61 , and calculate the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 , so that the operating frequency of compressor 1 , the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 Matching with the operating conditions of the heat pump equipment, the compressor 1 can operate stably at an adapted frequency while meeting the load demand, ensuring that the heat pump equipment outputs optimal heat, thereby increasing the system circulation flow, thereby improving energy efficiency, and reducing the system exhaust temperature to ensure stable operation of the unit.

[0082] It is understandable that when ; The controller calculates the current ambient temperature And water inlet temperature , calculate the operating frequency of compressor 1 , and calculate the opening degree of the first expansion valve 51 and the opening degree of the second expansion valve 61 The controller controls the compressor 1 to operate at the frequency Continuous operation ensures the continuous output of the heat pump equipment, reduces temperature fluctuations, improves comfort, and avoids shutdown of the heat pump equipment and repeated startup, thereby reducing energy consumption.

[0083] In some embodiments of the present invention, the controller receives the suction temperature in real time and coil temperature , the controller has a target suction temperature And the first hysteresis threshold, the controller according to the formula:

[0084]

[0085] Get ,when When the absolute value of The absolute value of is less than the first hysteresis threshold, and the controller controls the first expansion valve 51 to decelerate and adjust; is a positive value, the controller controls the valve step of the first expansion valve 51 to increase. is a negative value, the controller controls the valve step of the first expansion valve 51 to decrease;

[0086] Specifically, when the calculated When it is positive, the controller controls the valve step of the first expansion valve 51 to increase. The absolute value of is greater than the first hysteresis threshold, the controller accelerates the adjustment of the first expansion valve 51 until After decreasing to less than or equal to the first hysteresis threshold, the controller decelerates and adjusts the first expansion valve 51; =0, the controller controls the first expansion valve 51 to operate at the current valve step.

[0087] The controller receives the exhaust temperature in real time and outlet water temperature , the controller has a target exhaust temperature And the second hysteresis threshold, according to the formula:

[0088]

[0089] Where ε is a constant, the controller calculates ;when When the absolute value of The absolute value of is less than the second hysteresis threshold, and the controller controls the second expansion valve 61 to decelerate and adjust; is a positive value, the controller controls the valve step of the second expansion valve 61 to increase. When it is a negative value, the controller controls the valve step of the second expansion valve 61 to decrease.

[0090] Similarly, when the calculated When it is positive, the controller controls the valve step of the first expansion valve 51 to increase. The absolute value of is greater than the second hysteresis threshold, the controller accelerates the adjustment of the second expansion valve 61 until After decreasing to less than or equal to the second hysteresis threshold, the controller decelerates and adjusts the second expansion valve 61; =0, the controller controls the second expansion valve 61 to operate at the current valve step.

[0091] In some embodiments of the present invention, the exhaust gas superheat parameter is set by the controller. and , set time parameters and , and set the regulating valve step parameters of the second expansion valve 61 and , the heat pump equipment is initially started and the controller detects the exhaust temperature ;

[0092] when , the controller controls the second expansion valve 61 at the time parameter Internal regulating valve step ;

[0093] when When the controller controls the second expansion valve 61 at the time parameter Internal regulating valve step ;

[0094] when When the controller obtains After comparison with the set second hysteresis threshold, the valve step adjustment of the second expansion valve 61 is controlled.

[0095] In some embodiments of the present invention, the first expansion valve 51 is regulated by PID control, and the controller sets the oscillation frequency adjustment parameter And temperature range parameters and ,in Greater than ;

[0096] Controller calculation acquisition ,when as well as When the actual number of adjustment oscillations exceeds the adjustment oscillation number parameter , the controller performs transition control. During transition control, the proportional coefficient in the PID control adjustment Halved.

[0097] Specifically, at the initial start-up of the heat pump equipment, The controller will speed up the valve step adjustment of the first expansion valve 51 due to negative feedback regulation. Due to the hysteresis of PID control regulation, the regulating valve step will exceed the target valve step, resulting in regulation oscillation. The controller detects the actual number of regulation oscillations and compares it with the preset regulation oscillation number parameter. When the actual number of adjustment oscillations exceeds the adjustment oscillation number parameter When the controller performs transition control, the proportional coefficient in the PID regulation Halved, so that the valve step tends to the target value.

[0098] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A control method for an air source heat pump control system, It is characterized in that Air source heat pump control system includes: A heat pump device, comprising a compressor (1), a first heat exchanger (2) and a second heat exchanger (3), and a first expansion valve (51) and a second expansion valve (61) arranged in series, wherein the first expansion valve (51) and the second expansion valve (61) are arranged between the first heat exchanger (2) and the second heat exchanger (3), the first heat exchanger (2) is connected to an external heat-using device via a water supply pipeline, and the first heat exchanger (2) is provided with a water inlet and a water outlet; A first temperature sensor is provided in the water inlet to detect the inlet water temperature. ; A second temperature sensor, the second temperature sensor is adapted to detect the ambient temperature ; A controller, wherein the compressor (1), the first expansion valve (51), the second expansion valve (61), the first temperature sensor and the second temperature sensor are all connected to the controller for communication, and the controller is adapted to receive the water inlet temperature and the ambient temperature , to control the operating frequency of the compressor (1) , and controlling the opening degree of the first expansion valve (51) and the opening degree of the second expansion valve (61) ; The control method comprises the following steps: Output cooling mode or heating mode command, the controller receives the outlet water temperature , and according to the formula: , controlling the compressor (1) to start a cooling mode or a heating mode; The controller receives the ambient temperature and initial water inlet temperature Based on the set frequency simulation table, the opening degree simulation table of the first expansion valve (51) and the opening degree simulation table of the second expansion valve (61), the calculation is performed at the ambient temperature. The initial water inlet temperature The corresponding operating frequency of the compressor (1) , and calculating the opening degree of the first expansion valve (51) and the opening degree of the second expansion valve (61) ; The controller receives the real-time inlet water temperature Based on the set frequency simulation table, the first expansion valve (51) opening simulation table and the second expansion valve (61) opening simulation table, the controller controls the ambient temperature in real time. The real-time inlet water temperature The corresponding operating frequency of the compressor (1) , and calculating the opening degree of the first expansion valve (51) and the opening degree of the second expansion valve (61) ; The controller receives the suction temperature in real time and coil temperature The controller is provided with a target suction temperature And the first hysteresis threshold, the controller according to the formula: To obtain ; When the The absolute value of the first hysteresis threshold is greater than the first hysteresis threshold, the controller controls the first expansion valve (51) to accelerate the adjustment. The absolute value of which is less than the first hysteresis threshold, the controller controls the first expansion valve (51) to decelerate and adjust; is a positive value, the controller controls the valve step of the first expansion valve (51) to increase, and the is a negative value, the controller controls the valve step of the first expansion valve (51) to decrease; The controller receives the exhaust temperature in real time and outlet water temperature , the controller is provided with a target exhaust temperature And the second hysteresis threshold, according to the formula: Where ε is a constant, the controller calculates ; When the The absolute value of the second hysteresis threshold is greater than the second hysteresis threshold, the controller controls the second expansion valve (61) to accelerate the adjustment. The absolute value of which is less than the second hysteresis threshold, the controller controls the second expansion valve (61) to decelerate and adjust; is a positive value, the controller controls the valve step of the second expansion valve (61) to increase, and the is a negative value, the controller controls the valve step of the second expansion valve (61) to decrease.

2. The control method of the air source heat pump control system according to claim 1, It is characterized in that The air source heat pump control system also includes a third temperature sensor, which is arranged in the water outlet to detect the outlet water temperature. The controller is preset with a target water outlet temperature threshold And the differential temperature The controller is adapted to receive the outlet water temperature , and according to the formula: , to control the compressor (1) to start or stop.

3. The control method of the air source heat pump control system according to claim 2, It is characterized in that The heat pump device has a heating mode and a cooling mode. In the heating mode: the return temperature The value is positive; in cooling mode, the return temperature The value is negative.

4. The control method of the air source heat pump control system according to claim 1, It is characterized in that The heat pump device further comprises a vaporizing device (4), the first expansion valve (51) being arranged between the first heat exchanger (2) and the vaporizing device (4), and the second expansion valve (61) being arranged between the vaporizing device (4) and the second heat exchanger (3); In the heating mode: the heat exchange medium flows out of the compressor (1), flows through the first heat exchanger (2), the first expansion valve (51), the vaporizer (4), the second expansion valve (61) and the second heat exchanger (3) in sequence, and flows back into the compressor (1) to form a first heating circuit; and flows through the first heat exchanger (2), the first expansion valve (51) and the vaporizer (4) in sequence, and flows back into the compressor (1) to form a second heating circuit; In the refrigeration mode: the heat exchange medium flows out of the compressor (1), flows through the second heat exchanger (3), the second expansion valve (61), the vaporizer (4), the first expansion valve (51) and the first heat exchanger (2), and flows back into the compressor (1) to form a first refrigeration circuit; and flows through the second heat exchanger (3), the second expansion valve (61) and the vaporizer (4), and flows back into the compressor (1) to form a second refrigeration circuit.

5. The control method of the air source heat pump control system according to claim 4, It is characterized in that The heat pump device further comprises a reversing valve body (7) communicatively connected to the controller, the reversing valve body (7) comprising a first valve port (71), a second valve port (72), a third valve port (73) and a fourth valve port (74), the first valve port (71) being in communication with a discharge port of the compressor (1), the second valve port (72) being in communication with the first heat exchanger (2), the third valve port (73) being in communication with a first return port of the compressor (1), and the fourth valve port (74) being in communication with the second heat exchanger (3); In the heating mode, the first valve port (71) is in communication with the second valve port (72), and the third valve port (73) is in communication with the fourth valve port (74); in the cooling mode, the first valve port (71) is in communication with the fourth valve port (74), and the second valve port (72) is in communication with the third valve port (73).

6. The control method of the air source heat pump control system according to claim 5, It is characterized in that The heat pump device further comprises a one-way valve (52) and a capillary tube (53); the one-way valve (52) and the capillary tube (53) are arranged in series, and the one-way valve (52), the capillary tube (53) and the first expansion valve (51) are arranged in parallel to form a first throttling group (5); the one-way valve (52) and the first expansion valve (51) are connected to the port close to the first heat exchanger (2) through the capillary tube (53); and the valve direction of the one-way valve (52) is arranged in the direction of flow from the second heat exchanger (3) to the first heat exchanger (2).

7. The control method of the air source heat pump control system according to claim 6, It is characterized in that A fourth temperature sensor is provided on a connecting pipe between the first valve port (71) and the exhaust port of the compressor (1), wherein the fourth temperature sensor is suitable for detecting the exhaust temperature of the compressor (1). A fifth temperature sensor is provided on the connecting pipeline between the third valve port (73) and the compressor (1), and the second temperature sensor is suitable for detecting the suction temperature of the compressor (1). The second heat exchanger (3) is provided with a sixth temperature sensor, and the sixth temperature sensor is suitable for detecting the coil temperature in the second heat exchanger (3). ; The fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor are all in communication with the controller, and the controller is adapted to receive the exhaust temperature , Intake temperature and coil temperature ; to control the regulation speed of the first expansion valve (51) and the regulation speed of the second expansion valve (61).

8. The control method of the air source heat pump control system according to claim 7, It is characterized in that The operating frequency of the compressor (1) , the opening degree of the first expansion valve (51) and the opening degree of the second expansion valve (61) Both are consistent with the inlet water temperature A linear function relationship; and / or The operating frequency of the compressor (1) , the opening degree of the first expansion valve (51) and the opening degree of the second expansion valve (61) The ambient temperature A linear function relationship.

9. The control method of the air source heat pump control system according to claim 1, It is characterized in that Set the exhaust superheat parameters through the controller and , set time parameters and , and setting the regulating valve step parameters of the second expansion valve (61) and , the heat pump equipment is initially started and the controller detects the exhaust temperature ; when The controller controls the second expansion valve (61) at a time parameter Internal regulating valve step ; when When the controller controls the second expansion valve (61) to Internal regulating valve step ; when When the controller obtains After comparison with a set second hysteresis threshold, the valve step adjustment of the second expansion valve (61) is controlled.

10. The control method of the air source heat pump control system according to claim 1, It is characterized in that The first expansion valve (51) is regulated by PID control, and the controller sets a parameter for regulating the number of oscillations. And temperature range parameters and ,in Greater than ; The controller calculates and obtains ,when as well as When the actual number of adjustment oscillations exceeds the number of adjustment oscillations parameter The controller performs transition control. During transition control, the proportional coefficient in the PID control adjustment Halved.

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