Jet Enthalpy-Enhanced Heat Pump Chilled Water System and Control Method

Abstract

The present invention provides a jet enthalpy-increasing heat pump chiller system and a control method. The system includes a jet enthalpy-increasing auxiliary circuit and an auxiliary circuit electronic expansion valve, and further includes: a compressor operation parameter detection module, an operation mode detection module, an outdoor ambient temperature detection module, an exhaust superheat acquisition module, and an auxiliary circuit superheat acquisition module; and a control module, which controls the opening or closing of the auxiliary circuit electronic expansion valve according to whether the detected operation time, operation frequency, operation mode, outdoor ambient temperature, and exhaust superheat meet the opening condition or closing condition of the auxiliary circuit electronic expansion valve. After the auxiliary circuit electronic expansion valve is opened, the opening degree of the auxiliary circuit electronic expansion valve is adjusted according to the comparison result between the auxiliary circuit superheat and the superheat preset value, and the adjustment starts from the initial opening degree of the auxiliary circuit electronic expansion valve as the minimum opening degree used. The present invention opens the auxiliary circuit electronic expansion valve through the above condition judgment, so that the system maintains the best operation state, ensuring the capacity, energy efficiency, and reliability of the unit.

Description

Technical Field

[0001] The present invention relates to the technical field of cold and hot water type air-conditioning heat pump units, and particularly to a jet enthalpy-increasing heat pump chilled water system and a control method therefor. Background Art

[0002] In the existing jet enthalpy-increasing heat pump units, the control conditions of the auxiliary electronic expansion valve cannot reflect the real-time oil temperature, resulting in that some liquid return cannot respond to the control in time; the hysteresis of the control conditions will cause the control action to lag; in addition, when the unit switches states or modes, such as entering or exiting defrosting, switching between refrigeration and heating, etc., controlling through the superheat at the inlet and outlet of the auxiliary circuit cannot ensure that the auxiliary electronic expansion valve is in a valve step without liquid return and there is hysteresis in the control, resulting in poor low-temperature heating capacity and operation reliability of the jet enthalpy-increasing heat pump unit. Summary of the Invention

[0003] Aiming at the above problems, the present invention provides a jet enthalpy-increasing heat pump chilled water system and a control method therefor. The opening or closing of the auxiliary electronic expansion valve is controlled according to whether the detected running time, running frequency, running mode, outdoor ambient temperature and exhaust superheat meet the opening condition or closing condition of the auxiliary electronic expansion valve. After the auxiliary electronic expansion valve is opened, the opening degree of the auxiliary electronic expansion valve is adjusted according to the comparison result between the auxiliary superheat and the preset value of superheat, and the adjustment starts from the initial opening degree of the auxiliary electronic expansion valve as the minimum opening degree used, so that the system maintains a better operating state, ensuring the capacity energy efficiency and reliability of the unit.

[0004] The present invention provides a jet enthalpy-increasing heat pump chilled water system, including a jet enthalpy-increasing auxiliary circuit, on which an auxiliary electronic expansion valve is provided. The jet enthalpy-increasing heat pump chilled water system further includes: a compressor operating parameter detection module for detecting the running time and running frequency of the compressor; a running mode detection module for detecting the running mode in which the jet enthalpy-increasing heat pump chilled water system is located; an outdoor ambient temperature detection module for detecting the outdoor ambient temperature; an exhaust superheat acquisition module for acquiring the exhaust superheat of the compressor; an auxiliary superheat acquisition module for acquiring the auxiliary superheat of the jet enthalpy-increasing auxiliary circuit; and a control module for controlling the opening or closing of the auxiliary electronic expansion valve according to whether the detected running time, running frequency, running mode, outdoor ambient temperature and exhaust superheat meet the opening condition or closing condition of the auxiliary electronic expansion valve, and after the auxiliary electronic expansion valve is opened, adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result between the auxiliary superheat and the preset value of superheat, and starting the adjustment from the initial opening degree of the auxiliary electronic expansion valve as the minimum opening degree used.

[0005] By detecting the running time of the compressor, the present invention can make the compressor run to the target frequency after a specified running time, ensuring that the unit reaches a stable state; by detecting the running frequency of the compressor, when the running frequency meets the opening condition, the auxiliary electronic expansion valve is opened, so that the compressor can ensure the service life of the compressor and the jet enthalpy increase auxiliary circuit does not need to be frequently opened and closed while meeting the system requirements, which is beneficial to extending the service life of the auxiliary electronic expansion valve of the jet enthalpy increase circuit; according to the mode in which the system is located and the outdoor ambient temperature, it is judged whether to open the auxiliary electronic expansion valve, while ensuring the system output capacity, the jet enthalpy increase auxiliary circuit does not need to be frequently opened; according to the exhaust superheat degree, it is judged whether to open the auxiliary electronic expansion valve, and the auxiliary circuit is opened when the system superheat degree is satisfied, reducing the liquid return risk of the jet enthalpy increase auxiliary circuit and extending the service life of the system. The opening degree of the auxiliary electronic expansion valve is adjusted according to the superheat degree of the auxiliary circuit, ensuring the superheat degree requirement of the jet enthalpy increase auxiliary circuit, and each time the opening degree of the auxiliary electronic expansion valve is adjusted starting from the minimum opening degree, ensuring that the system does not return liquid from the jet enthalpy increase auxiliary circuit, thereby ensuring the reliability of the system. The present invention ensures that the system is in a better operating state through the above aspects, and ensures the unit energy efficiency and reliability of the system; in addition, the jet enthalpy increase auxiliary circuit system ensures the heating capacity of the system under low temperature conditions.

[0006] In an alternative technical solution of the present invention, the opening conditions of the auxiliary electronic expansion valve include: whether the running time is greater than a specified time threshold, the exhaust superheat degree is greater than a specified superheat degree threshold, and the running frequency is greater than a specified frequency threshold; and in the heating mode, the outdoor ambient temperature is less than a first specified temperature threshold, in the cooling mode, the outdoor ambient temperature is greater than a second specified temperature threshold, and the running mode is a non-defrosting mode; the auxiliary electronic expansion valve is opened when all the opening conditions are met simultaneously, and is closed when any one of the opening conditions is not met.

[0007] According to this technical solution, when the running time of the compressor exceeds the specified time threshold, it can ensure that the compressor frequency reaches the target frequency. When the running frequency of the compressor is greater than the specified frequency threshold, it can meet the system requirements. When the exhaust superheat degree of the compressor is greater than the specified superheat degree threshold, it can ensure the superheat degree of the system and reduce the liquid return risk of the auxiliary circuit; according to the running mode in which the system is located and the outdoor ambient temperature, the auxiliary electronic expansion valve is opened in a timely manner, which is beneficial to ensuring the system output capacity. When all the above opening conditions are met, the auxiliary electronic expansion valve is opened, ensuring that the system is in a better energy efficiency range, which is beneficial to extending the service life of the system and ensuring the reliability of the system operation.

[0008] In an alternative technical solution of the present invention, adjusting the opening degree of the auxiliary circuit electronic expansion valve according to the comparison result between the superheat degree of the auxiliary circuit and the preset superheat degree value includes: when the superheat degree of the auxiliary circuit is greater than the first preset value, increasing the opening degree of the auxiliary circuit electronic expansion valve at the first speed; when the superheat degree of the auxiliary circuit is greater than the second preset value and less than the first preset value, increasing the opening degree of the auxiliary circuit electronic expansion valve at the second speed; when the superheat degree of the auxiliary circuit is greater than the third preset value and less than the second preset value, increasing the opening degree of the auxiliary circuit electronic expansion valve at the third speed, the first preset value, the second preset value, and the third preset value decrease in sequence, and the first speed, the second speed, and the third speed decrease in sequence.

[0009] According to this technical solution, by adjusting the opening speed of the auxiliary circuit electronic expansion valve at different adjustment speeds according to the range where the superheat degree of the auxiliary circuit is located, the system can tend to a stable state faster and maintain a better operating state, ensuring the energy efficiency and reliability of the system.

[0010] In an alternative technical solution of the present invention, adjusting the opening degree of the auxiliary circuit electronic expansion valve according to the comparison result between the superheat degree of the auxiliary circuit and the preset superheat degree value includes: when the superheat degree of the auxiliary circuit is less than the fourth preset value, closing the opening degree of the auxiliary circuit electronic expansion valve at the fourth speed; when the superheat degree of the auxiliary circuit is greater than the fourth preset value and less than the fifth preset value, closing the opening degree of the auxiliary circuit electronic expansion valve at the fifth speed, the fourth preset value is less than the fifth preset value, and the fourth speed is greater than the fifth speed.

[0011] According to this technical solution, by adjusting the closing speed of the auxiliary circuit electronic expansion valve at different adjustment speeds according to the range where the superheat degree of the auxiliary circuit is located, the system can tend to a stable state faster and maintain a better operating state, ensuring the energy efficiency and reliability of the system.

[0012] On the other hand, the present invention provides a control method for an ejector-enhanced heat pump chiller system. The ejector-enhanced heat pump chiller system includes an ejector-enhanced auxiliary circuit, and an auxiliary circuit electronic expansion valve is provided on the ejector-enhanced auxiliary circuit. The control method for the ejector-enhanced heat pump chiller system includes the following steps:

[0013] Detect the running time and running frequency of the compressor, detect the operating mode of the ejector-enhanced heat pump chiller system, and detect the outdoor ambient temperature; obtain the discharge superheat degree of the compressor and the superheat degree of the auxiliary circuit of the ejector-enhanced auxiliary circuit; control the opening or closing of the auxiliary circuit electronic expansion valve according to whether the detected running time, running frequency, operating mode, outdoor ambient temperature, and discharge superheat degree meet the opening condition or closing condition of the auxiliary circuit electronic expansion valve, and after opening the auxiliary circuit electronic expansion valve, adjust the opening degree of the auxiliary circuit electronic expansion valve according to the comparison result between the superheat degree of the auxiliary circuit and the preset superheat degree value, and start adjusting from the initial opening degree of the auxiliary circuit electronic expansion valve as the minimum opening degree used.

[0014] In an alternative technical solution of the present invention, the opening conditions of the auxiliary electronic expansion valve include: whether the running time is greater than a specified time threshold, the exhaust superheat degree is greater than a specified superheat degree threshold, and the running frequency is greater than a specified frequency threshold; and in the heating mode, the outdoor ambient temperature is less than a first specified temperature threshold, in the cooling mode, the outdoor ambient temperature is greater than a second specified temperature threshold, and the running mode is a non-defrosting mode; the auxiliary electronic expansion valve opens when all the opening conditions are satisfied simultaneously and closes when any one of the opening conditions is not satisfied.

[0015] In an alternative technical solution of the present invention, the steps of adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result between the auxiliary superheat degree and the preset superheat degree value include: the opening-up step: when the auxiliary superheat degree is greater than a first preset value, the opening degree of the auxiliary electronic expansion valve is increased at a first speed; when the auxiliary superheat degree is greater than a second preset value and less than the first preset value, the opening degree of the auxiliary electronic expansion valve is increased at a second speed; when the auxiliary superheat degree is greater than a third preset value and less than the second preset value, the opening degree of the auxiliary electronic expansion valve is increased at a third speed, the first preset value, the second preset value, and the third preset value decrease in sequence, and the first speed, the second speed, and the third speed decrease in sequence.

[0016] In an alternative technical solution of the present invention, the steps of adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result between the auxiliary superheat degree and the preset superheat degree value include: the closing-down step: when the auxiliary superheat degree is less than a fourth preset value, the opening degree of the auxiliary electronic expansion valve is decreased at a fourth speed; when the auxiliary superheat degree is greater than the fourth preset value and less than a fifth preset value, the opening degree of the auxiliary electronic expansion valve is decreased at a fifth speed, the fourth preset value is less than the fifth preset value, and the fourth speed is greater than the fifth speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the modularized jet-assisted enthalpy-increasing heat pump water chiller system in an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the refrigerant flow direction of the jet-assisted enthalpy-increasing heat pump water chiller system in the heating mode in an embodiment of the present invention.

[0019] Figure 3 It is a schematic diagram of the refrigerant flow direction of the jet-assisted enthalpy-increasing heat pump water chiller system in the cooling mode in an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of the flow chart of the control method of the jet-assisted enthalpy-increasing heat pump water chiller system in an embodiment of the present invention.

[0021] Reference Signs:

[0022] Compressor 1; four-way valve 11; subcooler 12; refrigerant / water heat exchanger 13; main electronic expansion valve 14; refrigerant heat dissipation pipe 15; capillary tube 16; finned tube heat exchanger 17; gas-liquid separator 18; jet enthalpy-increasing bypass 2; bypass electronic expansion valve 21; compressor operating parameter detection module 31; operating mode detection module 32; outdoor ambient temperature detection module 33; exhaust superheat acquisition module 34; bypass superheat acquisition module 35. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Please refer to Figure 1 、 Figure 2 As shown, the present invention provides a jet enthalpy-increasing heat pump water chiller system, including a compressor 1 and a jet enthalpy-increasing bypass 2. A bypass electronic expansion valve 21 is provided on the jet enthalpy-increasing bypass 2. The jet enthalpy-increasing heat pump water chiller system further includes: a compressor operating parameter detection module that detects the operating time and operating frequency of the compressor 1; an operating mode detection module 32 that detects the operating mode of the jet enthalpy-increasing heat pump water chiller system; an outdoor ambient temperature detection module 33 that detects the outdoor ambient temperature; an exhaust superheat acquisition module 34 that acquires the exhaust superheat of the compressor 1; a bypass superheat acquisition module 35 that acquires the bypass superheat of the jet enthalpy-increasing bypass 2; a control module 36 that controls the opening or closing of the bypass electronic expansion valve 21 according to whether the detected operating time, operating frequency, operating mode, outdoor ambient temperature, and exhaust superheat meet the opening condition or closing condition of the bypass electronic expansion valve 21, and after opening the bypass electronic expansion valve 21, adjusts the opening degree of the bypass electronic expansion valve 21 according to the comparison result between the bypass superheat and the preset superheat value, and starts the adjustment with the initial opening degree of the bypass electronic expansion valve 21 as the minimum opening degree used.

[0025] By detecting the operating time of the compressor 1, the present invention enables the compressor 1 to operate at the target frequency after a specified operating time, ensuring that the unit reaches a stable state; by detecting the operating frequency of the compressor 1, when the operating frequency meets the opening condition, the auxiliary electronic expansion valve 21 is opened, so that under the condition of meeting the system requirements, the life of the compressor 1 and the jet enthalpy increase auxiliary circuit are not frequently opened and closed, which is beneficial to extending the service life of the jet enthalpy increase auxiliary electronic expansion valve 21; according to the mode in which the system is located and the outdoor ambient temperature, it is judged whether to open the auxiliary electronic expansion valve 21, while ensuring the system output capacity, the jet enthalpy increase auxiliary circuit 2 is not frequently opened; according to the exhaust superheat degree, it is judged whether to open the auxiliary electronic expansion valve 21, and the auxiliary circuit is opened under the condition that the system superheat degree is satisfied, reducing the liquid return risk of the jet enthalpy increase auxiliary circuit 2 and extending the service life of the system. According to the auxiliary superheat degree, the opening degree of the auxiliary electronic expansion valve 21 is adjusted, ensuring the superheat degree requirement of the jet enthalpy increase auxiliary circuit 2, and each time the opening degree of the auxiliary electronic expansion valve 21 is adjusted starting from the minimum opening degree, ensuring that the system does not return liquid from the jet enthalpy increase auxiliary circuit 2, thereby ensuring the reliability of the system. The present invention ensures that the system is in a better operating state through the above aspects, and ensures the unit energy efficiency and reliability of the system; in addition, the jet enthalpy increase auxiliary circuit system ensures the heating capacity of the system under low temperature conditions.

[0026] As Figure 2 shown, in a specific embodiment of the present invention, the jet enthalpy increase heat pump water system includes a refrigerant circulation system formed by a compressor 1, a four-way valve 11, a subcooler 12 (specifically a plate heat exchanger), a refrigerant / water heat exchanger 13, a main electronic expansion valve 14, a refrigerant heat dissipation pipe 15, a capillary tube 16, an outdoor heat exchanger / finned tube heat exchanger 17, and a gas-liquid separator 18; in the heating mode, the refrigerant passes through the compressor 1 (compression) → four-way valve 11 (direction selection) → refrigerant / water heat exchanger 13 (condensation, heating water) → subcooler 12 (the plate heat exchanger subcools the main circuit refrigerant and evaporates the auxiliary circuit refrigerant) → main electronic expansion valve 14 (throttling, controlling the refrigerant injection volume), and then passes through the auxiliary electronic expansion valve 21 and is vaporized and sprayed back into the compressor 1 through the plate heat exchanger → liquid passes through the refrigerant heat dissipation pipe 15 → capillary tube 16 (throttling) → outdoor heat exchanger / finned tube heat exchanger 17 (evaporation) → four-way valve 11 (direction selection) → gas-liquid separator 18 (separating the liquid to ensure the dryness of the return gas) → compressor 1.

[0027] As Figure 3As shown, in the refrigeration mode, the compressor 1 (compresses) → the four-way valve 11 (selects the direction) → the outdoor heat exchanger / finned tube heat exchanger 17 (condenses, dissipates heat) → the capillary tube 16 (throttles) → the refrigerant heat dissipation tube 15 → the main electronic expansion valve 14 (throttles, controls the inlet temperature of the refrigerant radiator to prevent condensation), the auxiliary electronic expansion valve 21, and then vaporizes and sprays back into the compressor 1 through the plate heat exchanger → the subcooler 12 (the plate heat exchanger subcools the main path refrigerant and evaporates the auxiliary path refrigerant) → the refrigerant / water heat exchanger 13 (evaporates and absorbs heat, cools the water) → the four-way valve 11 (selects the direction) → the gas-liquid separator 18 (separates the liquid to ensure the dryness of the return gas) → the compressor 1.

[0028] In the preferred embodiment of the present invention, the opening conditions of the auxiliary electronic expansion valve 21 include: whether the operating time is greater than the specified time threshold, the exhaust superheat degree is greater than the specified superheat degree threshold, and the operating frequency is greater than the specified frequency threshold; and in the heating mode, the outdoor ambient temperature is less than the first specified temperature threshold, in the refrigeration mode, the outdoor ambient temperature is greater than the second specified temperature threshold, and the operating mode is a non-defrosting mode; the auxiliary electronic expansion valve 21 opens when all the opening conditions are met simultaneously and closes when any one of the opening conditions is not met.

[0029] Specifically, when the operating time of the compressor 1 exceeds the specified time threshold (e.g., ≥ M min), it can ensure that the operating frequency of the compressor 1 reaches the target frequency; in the refrigeration / heating mode, when the operating frequency of the compressor 1 is greater than the specified frequency threshold d, the auxiliary electronic expansion valve 21 is opened, and when the operating frequency of the compressor 1 is less than the specified frequency threshold d, the auxiliary electronic expansion valve 21 is closed; when the compressor 1 operates in the better efficiency region while meeting the system requirements, there is no need to open the jet auxiliary path, and the specified frequency threshold d can be different in the refrigeration / heating mode. In the refrigeration / heating mode, when the exhaust superheat degree of the compressor 1 is greater than the specified superheat degree threshold C °C, the auxiliary electronic expansion valve 21 is opened, and when the exhaust superheat degree of the compressor 1 is greater than the specified superheat degree threshold C °C, the auxiliary electronic expansion valve 21 is closed, which can ensure the superheat degree of the system and reduce the risk of liquid return in the auxiliary path; the specified superheat degree threshold C can be different in different modes. According to the operating mode of the system and the outdoor ambient temperature, opening the auxiliary electronic expansion valve 21 in a timely manner is beneficial to ensuring the output capacity of the system. For example, in the refrigeration mode, above the outer ring temperature of a °C, the jet auxiliary path can be opened, and below a °C, it is closed; in the heating mode, above the outer ring temperature of b °C, the jet auxiliary path is closed, and below b °C, it can be opened; when all the above opening conditions are met simultaneously, the auxiliary electronic expansion valve 21 is opened, ensuring that the system is in a better energy efficiency range, especially the energy efficiency in the refrigeration / heating mode, which is beneficial to extending the service life of the system and ensuring the reliability of the system operation.

[0030] In a preferred embodiment of the present invention, it further includes a first temperature sensor T1 provided at the inlet of the tube-fin heat exchanger 17, a second temperature sensor T2 for detecting the outdoor ambient temperature, a third temperature sensor T3 provided at the outlet of the compressor 1, a fourth temperature sensor T4 provided at the outlet of the auxiliary circuit, and a fifth temperature sensor T5 provided at the inlet of the auxiliary circuit. The superheat of the auxiliary circuit is the difference between the temperature at the outlet of the auxiliary circuit and the temperature at the inlet of the auxiliary circuit. By obtaining the difference between the exhaust temperature of the compressor 1 and the saturation temperature corresponding to the inlet temperature and the actual condensation pressure of the condenser (obtained by a pressure sensor, where the pressure sensor is not shown), the exhaust superheat of the compressor 1 is calculated.

[0031] In a preferred embodiment of the present invention, the jet-enhanced heat pump chiller system further includes a data processing module 37 and a judgment module 38. The data processing module 37 calculates the superheat of the auxiliary circuit according to the obtained temperature at the outlet of the auxiliary circuit and the temperature at the inlet of the auxiliary circuit, and calculates the exhaust superheat according to the obtained exhaust temperature of the compressor, the condenser pressure and the corresponding saturation temperature. The judgment module 38 is used to judge whether the compressor operation time, operation frequency, system operation mode, outdoor ambient temperature and exhaust superheat meet the opening condition or closing condition of the auxiliary electronic expansion valve 21. Further, it also includes a memory (not shown in the figure) for storing the preset values and judgment conditions involved.

[0032] In a preferred embodiment of the present invention, adjusting the opening degree of the auxiliary electronic expansion valve 21 according to the comparison result between the superheat of the auxiliary circuit and the preset superheat value includes: when the superheat of the auxiliary circuit is greater than the first preset value, increasing the opening degree of the auxiliary electronic expansion valve 21 at the first speed; when the superheat of the auxiliary circuit is greater than the second preset value and less than the first preset value, increasing the opening degree of the auxiliary electronic expansion valve 21 at the second speed; when the superheat of the auxiliary circuit is greater than the third preset value and less than the second preset value, increasing the opening degree of the auxiliary electronic expansion valve 21 at the third speed. The first preset value, the second preset value, and the third preset value decrease in sequence, and the first speed, the second speed, and the third speed decrease in sequence.

[0033] By the above method, according to the range where the superheat of the auxiliary circuit is located, adjusting the opening speed of the auxiliary electronic expansion valve 21 at different adjustment speeds can enable the system to reach a stable state faster and maintain a better operating state, ensuring the energy efficiency and reliability of the system.

[0034] In a preferred embodiment of the present invention, adjusting the opening degree of the auxiliary electronic expansion valve 21 according to the comparison result between the superheat of the auxiliary circuit and the preset superheat value includes: when the superheat of the auxiliary circuit is less than the fourth preset value, closing the auxiliary electronic expansion valve 21 at the fourth speed; when the superheat of the auxiliary circuit is greater than the fourth preset value and less than the fifth preset value, closing the auxiliary electronic expansion valve 21 at the fifth speed. The fourth preset value is less than the fifth preset value, and the fourth speed is greater than the fifth speed.

[0035] In the above manner, according to the range of the superheat degree of the auxiliary circuit, the closing speed of the electronic expansion valve 21 of the auxiliary circuit is adjusted at different adjustment speeds, which can make the system tend to a stable state faster, maintain a better operating state, and ensure the energy efficiency and reliability of the system.

[0036] In the preferred embodiment of the present invention, a 10HP integral low-temperature variable-frequency air source heat pump (chilled water) unit ensures low-temperature strong heating, and at the same time realizes the second-level energy efficiency in heating and the first-level energy efficiency in cooling through the combination of this system and the control scheme of the auxiliary circuit electronic expansion valve.

[0037] Such as Figure 4 As shown, corresponding to the jet-injected heat pump chilled water system of the embodiment of the present invention, the present invention further provides a control method for a jet-injected heat pump chilled water system. The jet-injected heat pump chilled water system includes a jet-injected auxiliary circuit, and an electronic expansion valve 21 of the auxiliary circuit is provided on the jet-injected auxiliary circuit. The control method for the jet-injected heat pump chilled water system includes the following steps:

[0038] Detect the running time and running frequency of the compressor 1, detect the operating mode of the jet-injected heat pump chilled water system, and detect the outdoor ambient temperature; obtain the exhaust superheat degree of the compressor 1 and the superheat degree of the auxiliary circuit of the jet-injected auxiliary circuit; according to whether the detected running time, running frequency, operating mode, outdoor ambient temperature, and exhaust superheat degree meet the opening condition or closing condition of the electronic expansion valve 21 of the auxiliary circuit, control the opening or closing of the electronic expansion valve 21 of the auxiliary circuit, and after opening the electronic expansion valve 21 of the auxiliary circuit, adjust the opening degree of the electronic expansion valve 21 of the auxiliary circuit according to the comparison result between the superheat degree of the auxiliary circuit and the preset superheat degree value, and start adjusting with the initial opening degree of the electronic expansion valve 21 of the auxiliary circuit as the minimum opening degree used.

[0039] In the preferred embodiment of the present invention, the opening conditions of the electronic expansion valve 21 of the auxiliary circuit include: whether the running time is greater than the specified time threshold, the exhaust superheat degree is greater than the specified superheat degree threshold, and the running frequency is greater than the specified frequency threshold; and in the heating mode, the outdoor ambient temperature is less than the first specified temperature threshold, in the cooling mode, the outdoor ambient temperature is greater than the second specified temperature threshold, and the operating mode is a non-defrosting mode; the electronic expansion valve 21 of the auxiliary circuit opens when all the opening conditions are met and closes when any of the opening conditions is not met.

[0040] In a preferred embodiment of the present invention, the steps of adjusting the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result between the superheat degree of the auxiliary circuit and the preset value of the superheat degree include: the opening-up step: when the superheat degree of the auxiliary circuit is greater than the first preset value, increasing the opening degree of the auxiliary circuit electronic expansion valve 21 at the first speed; when the superheat degree of the auxiliary circuit is greater than the second preset value and less than the first preset value, increasing the opening degree of the auxiliary circuit electronic expansion valve 21 at the second speed; when the superheat degree of the auxiliary circuit is greater than the third preset value and less than the second preset value, increasing the opening degree of the auxiliary circuit electronic expansion valve 21 at the third speed, the first preset value, the second preset value, and the third preset value decrease in sequence, and the first speed, the second speed, and the third speed decrease in sequence.

[0041] In a preferred embodiment of the present invention, the steps of adjusting the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result between the superheat degree of the auxiliary circuit and the preset value of the superheat degree include: the closing-down step: when the superheat degree of the auxiliary circuit is less than the fourth preset value, closing down the opening degree of the auxiliary circuit electronic expansion valve 21 at the fourth speed; when the superheat degree of the auxiliary circuit is greater than the fourth preset value and less than the fifth preset value, closing down the opening degree of the auxiliary circuit electronic expansion valve 21 at the fifth speed, the fourth preset value is less than the fifth preset value, and the fourth speed is greater than the fifth speed.

[0042] In a preferred embodiment of the present invention, it further includes cyclically detecting the running time and running frequency of the compressor 1, detecting the running mode of the jet enthalpy-increasing heat pump chiller system, and detecting the outdoor ambient temperature; obtaining the exhaust superheat degree of the compressor 1 and the superheat degree of the auxiliary circuit of the jet enthalpy-increasing auxiliary circuit; controlling the opening or closing of the auxiliary circuit electronic expansion valve 21 according to whether the detected running time, running frequency, running mode, outdoor ambient temperature, and exhaust superheat degree meet the opening condition or closing condition of the auxiliary circuit electronic expansion valve 21, and after opening the auxiliary circuit electronic expansion valve 21, adjusting the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result between the superheat degree of the auxiliary circuit and the preset value of the superheat degree, and starting the adjustment with the initial opening degree of the auxiliary circuit electronic expansion valve 21 as the minimum opening degree used.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A jet-increased enthalpy heat pump chilled water system, including a jet-increased enthalpy auxiliary circuit, wherein an auxiliary circuit electronic expansion valve is provided on the jet-increased enthalpy auxiliary circuit, characterized in that, The jet enthalpy-increasing heat pump chiller system further includes: A compressor operation parameter detection module for detecting the operation time and operation frequency of the compressor; An operation mode detection module for detecting the operation mode of the jet enthalpy-increasing heat pump chiller system; An outdoor ambient temperature detection module for detecting the outdoor ambient temperature; An exhaust superheat acquisition module for acquiring the exhaust superheat of the compressor; An auxiliary path superheat acquisition module for acquiring the superheat of the auxiliary path of the jet enthalpy-increasing auxiliary path; A control module for controlling the opening or closing of the auxiliary path electronic expansion valve according to whether the detected operation time, operation frequency, operation mode, outdoor ambient temperature and exhaust superheat meet the opening condition or closing condition of the auxiliary path electronic expansion valve, and after opening the auxiliary path electronic expansion valve, adjusting the opening degree of the auxiliary path electronic expansion valve according to the comparison result between the superheat of the auxiliary path and the preset superheat value, and starting the adjustment with the initial opening degree of the auxiliary path electronic expansion valve as the minimum opening degree used; The opening condition of the auxiliary path electronic expansion valve includes: the operation time is greater than a specified time threshold, the exhaust superheat is greater than a specified superheat threshold, the operation frequency is greater than a specified frequency threshold; and in the heating mode, the outdoor ambient temperature is less than a first specified temperature threshold, in the cooling mode, the outdoor ambient temperature is greater than a second specified temperature threshold, and the operation mode is a non-defrost mode; the auxiliary path electronic expansion valve opens when all the opening conditions are met simultaneously and closes when any of the opening conditions is not met.

2. The jet-increased enthalpy heat pump chilled water system according to claim 1, wherein The "adjusting the opening degree of the auxiliary path electronic expansion valve according to the comparison result between the superheat of the auxiliary path and the preset superheat value" includes: When the superheat of the auxiliary path is greater than a first preset value, increasing the opening degree of the auxiliary path electronic expansion valve at a first speed; when the superheat of the auxiliary path is greater than a second preset value and less than the first preset value, increasing the opening degree of the auxiliary path electronic expansion valve at a second speed; when the superheat of the auxiliary path is greater than a third preset value and less than the second preset value, increasing the opening degree of the auxiliary path electronic expansion valve at a third speed, the first preset value, the second preset value, and the third preset value decrease in sequence, and the first speed, the second speed, and the third speed decrease in sequence.

3. The control method of the jet enthalpy-increasing heat pump chiller system according to claim 1, wherein The "adjusting the opening degree of the auxiliary path electronic expansion valve according to the comparison result between the superheat of the auxiliary path and the preset superheat value" includes: When the superheat of the auxiliary path is less than a fourth preset value, closing the opening degree of the auxiliary path electronic expansion valve at a fourth speed; when the superheat of the auxiliary path is greater than the fourth preset value and less than a fifth preset value, closing the opening degree of the auxiliary path electronic expansion valve at a fifth speed, the fourth preset value is less than the fifth preset value, and the fourth speed is greater than the fifth speed.

4. A control method for a jet-injected enthalpy-increasing heat pump chiller system, the jet-injected enthalpy-increasing heat pump chiller system includes a jet-injected enthalpy-increasing auxiliary circuit, and an auxiliary electronic expansion valve is provided on the jet-injected enthalpy-increasing auxiliary circuit, characterized in that, The control method of the jet enthalpy-increasing heat pump chiller system includes the following steps: Detecting the operation time and operation frequency of the compressor, detecting the operation mode of the jet enthalpy-increasing heat pump chiller system, and detecting the outdoor ambient temperature; Acquiring the exhaust superheat of the compressor and the superheat of the auxiliary path of the jet enthalpy-increasing auxiliary path; Control the opening or closing of the auxiliary electronic expansion valve according to whether the detected running time, running frequency, running mode, outdoor ambient temperature, and exhaust superheat degree meet the opening condition or closing condition of the auxiliary electronic expansion valve. After opening the auxiliary electronic expansion valve, adjust the opening degree of the auxiliary electronic expansion valve according to the comparison result between the auxiliary superheat degree and the preset superheat degree value, and start adjusting with the initial opening degree of the auxiliary electronic expansion valve as the minimum opening degree used; The opening conditions of the auxiliary electronic expansion valve include: the running time is greater than the specified time threshold, the exhaust superheat degree is greater than the specified superheat degree threshold, and the running frequency is greater than the specified frequency threshold; and in the heating mode, the outdoor ambient temperature is less than the first specified temperature threshold, in the cooling mode, the outdoor ambient temperature is greater than the second specified temperature threshold, and the running mode is a non-defrosting mode; the auxiliary electronic expansion valve opens when all the opening conditions are met and closes when any of the opening conditions is not met.

5. The control method of the jet enthalpy-increasing heat pump chiller system according to claim 4, wherein, The "adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result between the auxiliary superheat degree and the preset superheat degree value" includes: Opening-up step: When the auxiliary superheat degree is greater than the first preset value, increase the opening degree of the auxiliary electronic expansion valve at the first speed; when the auxiliary superheat degree is greater than the second preset value and less than the first preset value, increase the opening degree of the auxiliary electronic expansion valve at the second speed; when the auxiliary superheat degree is greater than the third preset value and less than the second preset value, increase the opening degree of the auxiliary electronic expansion valve at the third speed. The first preset value, the second preset value, and the third preset value decrease in sequence, and the first speed, the second speed, and the third speed decrease in sequence.

6. The control method of the jet enthalpy-increasing heat pump chiller system according to claim 4, characterized in that, The "adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result between the auxiliary superheat degree and the preset superheat degree value" includes: Closing-down step: When the auxiliary superheat degree is less than the fourth preset value, reduce the opening degree of the auxiliary electronic expansion valve at the fourth speed; when the auxiliary superheat degree is greater than the fourth preset value and less than the fifth preset value, reduce the opening degree of the auxiliary electronic expansion valve at the fifth speed. The fourth preset value is less than the fifth preset value, and the fourth speed is greater than the fifth speed.

Images