CN115560496A - Air jet enthalpy increasing heat pump cooling system and control method - Google Patents

Abstract

The invention provides a cooling water system and a control method for an air injection enthalpy-increasing heat pump. The system includes an auxiliary circuit for increasing enthalpy by air injection and an electronic expansion valve for the auxiliary circuit. The superheat degree acquisition module, the auxiliary road superheat degree acquisition module; and the control module, 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 auxiliary circuit electronic expansion valve. Open or close the electronic expansion valve of the auxiliary circuit, and after opening the electronic expansion valve of the auxiliary circuit, adjust the opening degree of the electronic expansion valve of the auxiliary circuit according to the comparison result of the superheat of the auxiliary circuit and the preset value of the superheat, and use the initial opening of the electronic expansion valve of the auxiliary circuit as the start to adjust the minimum opening. The present invention judges and opens the electronic expansion valve of the auxiliary circuit according to the above conditions, so that the system can be kept in the best operating state, and the capacity, energy efficiency and reliability of the unit can be guaranteed.

Description

Air jet enthalpy increasing heat pump cooling system and control method

technical field

The invention relates to the technical field of hot and cold water type air-conditioning heat pump units, in particular to a cooling water system and a control method for an air injection enthalpy increasing heat pump unit.

Background technique

In the existing air-injection enthalpy-increasing heat pump unit, the control condition of the auxiliary circuit electronic expansion valve cannot reflect the real-time oil temperature, resulting in partial liquid return that cannot be controlled in time; the hysteresis of the control condition will cause the control action to lag; When switching, such as entering and exiting defrosting, cooling and heating switching, etc., the control of the superheat of the auxiliary circuit inlet and outlet cannot ensure that the electronic expansion valve of the auxiliary circuit is in a valve step that does not return liquid and there is a hysteresis in the control, which leads to the air injection enthalpy increase heat pump unit. The low-temperature heating capacity and operational reliability are poor.

Contents of the invention

In view of the above problems, the present invention provides a cooling water system and control method of an air injection enthalpy heat pump, according to whether the detected operating time, operating frequency, operating mode, outdoor ambient temperature and exhaust superheat meet the opening conditions of the electronic expansion valve of the auxiliary circuit or closing conditions to control the opening or closing 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 of the auxiliary circuit superheat and the superheat preset value, and use the auxiliary circuit electronic expansion valve The initial opening is adjusted from the minimum opening used to keep the system in an optimal operating state and ensure the capacity, energy efficiency and reliability of the unit.

The invention provides a heat pump cooling system for increasing enthalpy by air injection, which includes an auxiliary road for increasing enthalpy by air injection. The auxiliary road for increasing enthalpy by air injection is equipped with an electronic expansion valve in the auxiliary circuit. Operating time and operating frequency; operating mode detection module, which detects the operating mode of the air injection heat pump cooling water system; outdoor ambient temperature detection module, which detects the outdoor ambient temperature; exhaust superheat acquisition module, which obtains the exhaust superheat of the compressor ;Auxiliary road superheat acquisition module, obtains the auxiliary road superheat degree of the auxiliary road for enthalpy-increasing; the control module, according to the detected running time, running frequency, running mode, outdoor ambient temperature and exhaust superheat, whether it meets the opening conditions of the auxiliary road electronic expansion valve or closing conditions to control the opening or closing 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 of the auxiliary circuit superheat and the superheat preset value, and use the auxiliary circuit electronic expansion valve The initial opening is the minimum opening used to start adjustment.

By detecting the running time of the compressor, the present invention can make the compressor run to the target frequency after the specified running time to ensure that the unit reaches a stable state; by detecting the running frequency of the compressor, when the running frequency meets the opening condition, the electronic expansion valve of the auxiliary circuit is opened , so that the compressor meets the system requirements, ensuring the life of the compressor and the air injection enthalpy increase auxiliary circuit without frequent opening and closing, which is conducive to prolonging the service life of the electronic expansion valve in the air injection enthalpy increase auxiliary circuit; according to the mode of the system and the outdoor environment The temperature judges whether to open the electronic expansion valve of the auxiliary circuit. While ensuring the output capacity of the system, it is not necessary to frequently open the auxiliary circuit for increasing enthalpy by gas injection; judge whether to open the electronic expansion valve of the auxiliary circuit according to the superheat of the exhaust gas, and open the auxiliary circuit when the superheat of the system is satisfied. The risk of liquid return in the auxiliary circuit of gas injection enthalpy increase prolongs the service life of the system, and the opening of the electronic expansion valve of the auxiliary circuit is adjusted according to the superheat of the auxiliary circuit to ensure the superheat requirement of the auxiliary circuit of gas injection enthalpy increase, and the electronic expansion valve of the auxiliary circuit is adjusted from the minimum opening each time. The opening of the expansion valve ensures that the system does not return liquid from the gas injection enthalpy increasing auxiliary path, 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 energy efficiency and reliability of the system unit; in addition, the air injection enthalpy increasing auxiliary circuit system ensures the heating capacity of the system under low temperature conditions.

In the optional technical solution of the present invention, the opening conditions of the auxiliary circuit electronic expansion valve include: whether the operating time is greater than the specified time threshold, whether the exhaust gas superheat is greater than the specified superheat threshold, and the operating frequency is greater than the specified frequency threshold; and in the heating mode, The outdoor ambient temperature is lower than the first specified temperature threshold. In cooling mode, the outdoor ambient temperature is greater than the second specified temperature threshold. The operation mode is non-defrosting mode. Closed when the condition is turned on.

According to the technical solution, when the operating time of the compressor exceeds the specified time threshold, the compressor frequency can be guaranteed to reach the target frequency, the operating frequency of the compressor is greater than the specified frequency threshold, which can meet the system requirements, and the superheat of the compressor exhaust is greater than the specified superheat The threshold value can ensure the superheat of the system and reduce the risk of liquid return in the auxiliary circuit; according to the operating mode of the system and the outdoor ambient temperature, opening the electronic expansion valve of the auxiliary circuit in a timely manner is conducive to ensuring the output capacity of the system. The expansion valve ensures that the system is in a better energy efficiency range, which is beneficial to prolonging the service life of the system and ensuring the reliability of the system operation.

In the optional technical solution of the present invention, adjusting the opening of the electronic expansion valve of the auxiliary circuit according to the comparison result of the superheat degree of the auxiliary circuit with the preset value of the superheat degree includes: the superheat degree of the auxiliary circuit is greater than the first preset value, and the auxiliary circuit is increased at the first speed. The opening degree of the electronic expansion valve; the superheat degree of the auxiliary circuit is greater than the second preset value and less than the first preset value, and the opening degree of the electronic expansion valve of the auxiliary circuit is increased at the second speed; the superheat degree of the auxiliary circuit is greater than the third preset value and less than the first preset value Two preset values, increase the opening degree of the electronic expansion valve of the auxiliary circuit at the third speed, the first preset value, the second preset value, and the third preset value decrease in sequence, the first speed, the second speed, the third speed in descending order.

According to this technical scheme, according to the range of the superheat of the auxiliary circuit, the opening speed of the electronic expansion valve of the auxiliary circuit can be adjusted according to different adjustment speeds, which can make the system tend to a stable state faster and keep it in a better operating state, ensuring the system capability energy efficiency and reliability.

In the optional technical solution of the present invention, according to the comparison result of the superheat degree of the auxiliary circuit and the preset value of the superheat degree, adjusting the opening degree of the electronic expansion valve of the auxiliary circuit includes: the superheat degree of the auxiliary circuit is less than the fourth preset value, and the auxiliary circuit is closed at the fourth speed The opening degree of the electronic expansion valve; the superheat degree of the auxiliary circuit is greater than the fourth preset value and less than the fifth preset value, and the opening degree of the electronic expansion valve of the auxiliary circuit is closed at the fifth speed, and the fourth preset value is smaller than the fifth preset value, The fourth speed is greater than the fifth speed.

According to this technical scheme, according to the range of the superheat of the auxiliary circuit, the closing speed of the electronic expansion valve of the auxiliary circuit can be adjusted according to different adjustment speeds, which can make the system tend to a stable state faster and keep it in a better operating state, ensuring that the system capability energy efficiency and reliability.

Another aspect of the present invention provides a control method for the air injection enthalpy-increasing heat pump cooling water system. The air injection enthalpy increasing heat pump cooling water system includes an air injection enthalpy increasing auxiliary road. The air injection enthalpy increasing auxiliary road is provided with an auxiliary electronic expansion valve. The control method includes the following steps:

Detect the running time and frequency of the compressor, detect the operating mode of the air injection enthalpy heat pump cooling water system, and detect the outdoor ambient temperature; obtain the exhaust superheat of the compressor and the auxiliary road superheat of the air injection enthalpy auxiliary road; according to the detected Whether the operating time, operating frequency, operating mode, outdoor ambient temperature and exhaust superheat meet the opening or closing conditions of the auxiliary circuit electronic expansion valve to control the opening or closing of the auxiliary circuit electronic expansion valve, and after opening the auxiliary circuit electronic expansion valve, follow the auxiliary circuit electronic expansion valve. The comparison result of the degree of superheat and the preset value of the degree of superheat adjusts the opening degree of the auxiliary circuit electronic expansion valve, and the initial opening degree of the auxiliary circuit electronic expansion valve is used as the minimum opening degree for adjustment.

In the optional technical solution of the present invention, the opening conditions of the auxiliary circuit electronic expansion valve include: whether the operating time is greater than the specified time threshold, whether the exhaust gas superheat is greater than the specified superheat threshold, and the operating frequency is greater than the specified frequency threshold; and in the heating mode, The outdoor ambient temperature is lower than the first specified temperature threshold. In cooling mode, the outdoor ambient temperature is greater than the second specified temperature threshold. The operation mode is non-defrosting mode. Closed when the condition is turned on.

In the optional technical solution of the present invention, the step of adjusting the opening degree of the electronic expansion valve of the auxiliary circuit according to the comparison result of the degree of superheat of the auxiliary circuit and the preset value of the degree of superheat includes: a large opening step: the degree of superheat of the auxiliary circuit is greater than the first preset value, and the second Increase the opening degree of the electronic expansion valve of the auxiliary circuit at a speed; the superheat degree of the auxiliary circuit is greater than the second preset value and less than the first preset value, increase the opening degree of the electronic expansion valve of the auxiliary circuit at the second speed; the superheat degree of the auxiliary circuit is greater than the third preset value set value and less than the second preset value, increase the opening 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, the first speed, the second Speed, the third speed in descending order.

In the optional technical solution of the present invention, the step of adjusting the opening degree of the electronic expansion valve of the auxiliary circuit according to the comparison result of the degree of superheat of the auxiliary circuit with the preset value of the degree of superheat includes: a small closing step: the degree of superheat of the auxiliary circuit is less than the fourth preset value, and the first Four speeds to close the opening of the electronic expansion valve of the auxiliary circuit; the superheat of the auxiliary circuit is greater than the fourth preset value and less than the fifth preset value, and the opening of the electronic expansion valve of the auxiliary circuit is closed at the fifth speed, and the fourth preset value is smaller than the fifth preset value. Five preset values, the fourth speed is greater than the fifth speed.

Description of drawings

Fig. 1 is a schematic structural diagram of a modularized air injection enthalpy-increasing heat pump cooling water system in an embodiment of the present invention.

Fig. 2 is a schematic diagram of the flow of refrigerant in the air-injection enthalpy-increasing heat pump cooling water system in the heating mode in the embodiment of the present invention.

Fig. 3 is a schematic diagram of refrigerant flow in the cooling mode of the air injection enthalpy-increasing heat pump cooling water system in the embodiment of the present invention.

Fig. 4 is a schematic flow chart diagram of a control method of an air injection enthalpy-increasing heat pump cooling water system in an embodiment of the present invention.

Reference signs:

Compressor 1; four-way valve 11; subcooler 12; refrigerant/water heat exchanger 13; main electronic expansion valve 14; refrigerant cooling pipe 15; capillary tube 16; tube-fin heat exchanger 17; gas-liquid separator 18 Enthalpy auxiliary road 2; auxiliary road electronic expansion valve 21; compressor operating parameter detection module 31; operation mode detection module 32; outdoor environment temperature detection module 33; exhaust superheat degree acquisition module 34; auxiliary road superheat degree acquisition module 35.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to Fig. 1 and Fig. 2, the present invention provides a kind of air injection enthalpy heat pump cold water system, including compressor 1 and air injection enthalpy auxiliary road 2, the air injection enthalpy auxiliary road 2 is provided with auxiliary electronic expansion valve 21, air injection enthalpy increase The heat pump cold water system also includes: a compressor operating parameter detection module, which detects the running time and frequency of the compressor 1; an operating mode detection module 32, which detects the operating mode of the air injection heat pump cooling water system; an outdoor environment temperature detection module 33, Detect the outdoor ambient temperature; the exhaust superheat acquisition module 34 obtains the exhaust superheat of the compressor 1; the auxiliary road superheat acquisition module 35 acquires the auxiliary road superheat of the air injection enthalpy-increasing auxiliary road 2; the control module 36, according to the detected operation Whether the time, operating frequency, operating mode, outdoor ambient temperature and exhaust superheat meet the opening or closing conditions of the auxiliary circuit electronic expansion valve 21 to control the opening or closing of the auxiliary circuit electronic expansion valve 21, and after opening the auxiliary circuit electronic expansion valve 21, The opening degree of the auxiliary circuit electronic expansion valve 21 is adjusted according to the comparison result of the auxiliary circuit superheat degree and the superheat degree preset value, and the initial opening degree of the auxiliary circuit electronic expansion valve 21 is used as the minimum opening degree for adjustment.

By detecting the running time of the compressor 1, the present invention can make the compressor 1 run to the target frequency after a specified running time to ensure that the unit reaches a stable state; by detecting the running frequency of the compressor 1, when the running frequency meets the opening condition, the auxiliary circuit is opened The electronic expansion valve 21 enables the compressor 1 to ensure the life of the compressor 1 and the air injection enthalpy-increasing auxiliary circuit without frequent opening and closing when the compressor 1 meets the system requirements, which is beneficial to prolong the service life of the electronic expansion valve 21 in the air-injecting enthalpy-increasing auxiliary circuit; according to the system Judging whether to open the auxiliary circuit electronic expansion valve 21 according to the mode and the outdoor ambient temperature, while ensuring the system output capacity, it is not necessary to frequently open the auxiliary circuit 2 for increasing enthalpy by gas injection; judging whether to open the auxiliary circuit electronic expansion valve 21 according to the superheat of the exhaust gas to ensure the system When the superheat degree is satisfied, the auxiliary circuit is opened to reduce the risk of liquid return in the auxiliary circuit 2 for increasing enthalpy by air injection, and prolong the service life of the system. Requirements, and adjust the opening of the auxiliary circuit electronic expansion valve 21 from the minimum opening each time to ensure that the system does not return liquid from the gas injection enthalpy increasing 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 energy efficiency and reliability of the system unit; in addition, the air injection enthalpy increasing auxiliary circuit system ensures the heating capacity of the system under low temperature conditions.

As shown in Figure 2, in a specific embodiment of the present invention, the air injection enthalpy heat pump cold water system includes a compressor 1, a four-way valve 11, a subcooler 12 (specifically a plate heat exchanger), a refrigerant/water heat exchanger 13 , the main electronic expansion valve 14, the refrigerant cooling pipe 15, the capillary tube 16, the outdoor heat exchanger/tube-fin heat exchanger 17, and the refrigerant circulation system formed by the 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 (plate heat exchanger subcooling main circuit refrigerant, evaporation auxiliary circuit refrigerant) → main electronic expansion valve 14 (throttling, controlling the amount of air injection), the auxiliary circuit electronic expansion valve 21 is vaporized and sprayed back to the compressor 1 through the plate heat exchanger → the liquid subcooler cooling pipe 15 → the capillary tube 16 (throttling) → the outdoor heat exchanger/tube fin Heat exchanger 17 (evaporation) → four-way valve 11 (direction selection) → gas-liquid separator 18 (separate liquid to ensure return air dryness) → compressor 1.

As shown in Figure 3, in cooling mode, compressor 1 (compression) → four-way valve 11 (direction selection) → outdoor heat exchanger/tube-fin heat exchanger 17 (condensation, heat dissipation) → capillary tube 16 (throttling) → Refrigerant radiating pipe 15 → main electronic expansion valve 14 (throttling, controlling the inlet temperature of the refrigerant radiator to prevent condensation), auxiliary circuit electronic expansion valve 21 is vaporized and sprayed back to compressor 1 through the plate heat exchanger → subcooler 12 ( plate heat exchanger subcooling main circuit refrigerant, evaporating auxiliary circuit refrigerant) → refrigerant/water heat exchanger 13 (evaporation heat absorption, cooling water) → four-way valve 11 (direction selection) → gas-liquid separator 18 (separate liquid to ensure return Air dryness) → compressor 1.

In a preferred embodiment of the present invention, the opening conditions of the auxiliary circuit electronic expansion valve 21 include: whether the operating time is greater than a specified time threshold, whether the exhaust gas superheat is greater than a specified superheat threshold, and the operating frequency is greater than a specified frequency threshold; and in heating mode, The outdoor ambient temperature is lower than the first specified temperature threshold. In cooling mode, the outdoor ambient temperature is greater than the second specified temperature threshold. The operation mode is the non-defrosting mode. Closed on an open condition.

Specifically, when the operating time of compressor 1 exceeds the specified time threshold (such as ≥Mmin), it can ensure that the operating frequency of compressor 1 reaches the target frequency; in cooling/heating mode, the operating frequency of compressor 1 is greater than the specified frequency Threshold d, open the auxiliary circuit electronic expansion valve 21, the operating frequency of compressor 1 is less than the specified frequency threshold d, close the auxiliary circuit electronic expansion valve 21; compressor 1 does not need to be opened when it meets the system requirements and operates in the better efficiency area For the air injection auxiliary circuit, in the cooling/heating mode, the specified frequency threshold d can be different. In the cooling/heating mode, if the exhaust superheat of compressor 1 is greater than the specified superheat threshold C°C, the auxiliary circuit electronic expansion valve 21 is opened, and the exhaust superheat of compressor 1 is greater than the specified superheat threshold C°C, and the auxiliary electronic expansion valve 21 is turned off. The expansion valve 21 can ensure the superheat degree of the system and reduce the risk of liquid return in the auxiliary circuit; in different modes, the prescribed superheat degree threshold C can be different. According to the operating mode of the system and the outdoor ambient temperature, timely opening the auxiliary circuit electronic expansion valve 21 is beneficial to ensure the output capacity of the system. For example, in cooling mode, the air injection auxiliary circuit can be opened when the outer ring temperature is above a°C, and the air injection auxiliary circuit can be closed below a°C; In the heating mode, when the outer ring temperature is above b°C, the auxiliary air injection circuit is closed, and the auxiliary air injection circuit can be opened below b°C; at the same time, when the above opening conditions are met, the electronic expansion valve 21 of the auxiliary circuit is opened to ensure that the system is in a better energy efficiency range, especially in refrigeration. The energy efficiency in heating mode is beneficial to prolong the service life of the system and ensure the reliability of the system operation.

In the preferred embodiment of the present invention, it also includes a first temperature sensor T1 arranged at the inlet of the tube-fin heat exchanger 17, a second temperature sensor T2 for detecting the outdoor ambient temperature, and a third temperature sensor arranged at the outlet of the compressor 1 T3, the fourth temperature sensor T4 installed at the outlet of the auxiliary road and the fifth temperature sensor T5 installed at the inlet of the auxiliary road. The superheat of the auxiliary road is the difference between the temperature at the outlet of the auxiliary road and the temperature at the inlet of the auxiliary road. The temperature difference between the inlet temperature of the compressor and the saturation temperature corresponding to the actual condensing pressure (obtained by a pressure sensor, wherein the pressure sensor is not shown) is used to calculate the exhaust superheat of the compressor 1 .

In a preferred embodiment of the present invention, the air injection enthalpy-increasing heat pump cold water system also includes a data processing module 37 and a judgment module 38. The data processing module 37 calculates the degree of superheat of the auxiliary road according to the obtained auxiliary road outlet temperature and auxiliary road inlet temperature, and according to the obtained compression Calculate the superheat of the exhaust gas based on the exhaust temperature of the machine, the pressure of the condenser and the corresponding saturation temperature. The judging module 38 is used to judge whether the compressor running time, running frequency, system running mode, outdoor ambient temperature and exhaust superheat meet the opening condition or closing condition of the auxiliary circuit electronic expansion valve 21 . Further, a memory (not shown in the figure) is also included for storing related preset values and judgment conditions.

In a preferred embodiment of the present invention, adjusting the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result of the superheat degree of the auxiliary circuit and the preset value of the superheat degree includes: the superheat degree of the auxiliary circuit is greater than the first preset value, and the auxiliary circuit is increased at a first speed The opening degree of the electronic expansion valve 21; the superheat degree of the auxiliary circuit is greater than the second preset value and less than the first preset value, and the opening degree of the electronic expansion valve 21 of the auxiliary circuit is increased at the second speed; the superheat degree of the auxiliary circuit is greater than the third preset value and If it is less than the second preset value, the opening degree of the auxiliary circuit electronic expansion valve 21 is increased at the third speed, and the first preset value, the second preset value, and the third preset value are sequentially decreased, and the first speed, the second speed, The third speed is sequentially decreasing.

Through the above method, according to the range of the superheat of the auxiliary circuit, the opening speed of the electronic expansion valve 21 of the auxiliary circuit can be adjusted according to different adjustment speeds, which can make the system tend to a stable state faster and keep it in a better operating state, ensuring that the system capability energy efficiency and reliability.

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

Through the above method, according to the range of the superheat of the auxiliary circuit, the closing speed of the electronic expansion valve 21 of the auxiliary circuit can be adjusted according to different adjustment speeds, which can make the system tend to a stable state faster and keep it in a better operating state, ensuring that the system capability energy efficiency and reliability.

In the preferred embodiment of the present invention, the 10HP integrated low-temperature variable frequency air source heat pump (chiller) unit ensures low temperature and strong heat, and at the same time realizes the secondary energy efficiency of heating and the primary refrigeration through the system combined with the electronic expansion valve control scheme of the auxiliary circuit. efficiency.

As shown in Figure 4, corresponding to the air injection enthalpy increasing heat pump cooling water system in the embodiment of the present invention, the present invention also provides a control method for the air injection enthalpy increasing heat pump cooling water system. The enthalpy-increasing auxiliary road is provided with an auxiliary road electronic expansion valve 21, and the control method of the air injection enthalpy-increasing heat pump cooling water system includes the following steps:

Detect the running time and frequency of compressor 1, detect the operating mode of the air injection enthalpy heat pump cooling water system, and detect the outdoor ambient temperature; obtain the exhaust superheat of compressor 1 and the auxiliary road superheat of the air injection enthalpy auxiliary road; according to the detection Check whether the operating time, operating frequency, operating mode, outdoor ambient temperature and exhaust superheat meet the opening or closing conditions of the auxiliary circuit electronic expansion valve 21 to control the opening or closing of the auxiliary circuit electronic expansion valve 21, and then open the auxiliary circuit electronic expansion valve. After 21, adjust the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result of the superheat degree of the auxiliary circuit and the preset value of the superheat degree, and start the adjustment with the initial opening degree of the auxiliary circuit electronic expansion valve 21 as the minimum opening used.

In a preferred embodiment of the present invention, the opening conditions of the auxiliary circuit electronic expansion valve 21 include: whether the operating time is greater than a specified time threshold, whether the exhaust gas superheat is greater than a specified superheat threshold, and the operating frequency is greater than a specified frequency threshold; and in heating mode, The outdoor ambient temperature is lower than the first specified temperature threshold. In cooling mode, the outdoor ambient temperature is greater than the second specified temperature threshold. The operation mode is the non-defrosting mode. Closed on an open condition.

In a preferred embodiment of the present invention, the step of adjusting the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result of the superheat degree of the auxiliary circuit and the preset value of the superheat degree includes: the step of opening larger: the superheat degree of the auxiliary circuit is greater than the first preset value, and the second Increase the opening degree of the auxiliary circuit electronic expansion valve 21 at a speed; the superheat degree of the auxiliary circuit is greater than the second preset value and less than the first preset value, increase the opening degree of the auxiliary circuit electronic expansion valve 21 at the second speed; the auxiliary circuit superheat degree is greater than the first preset value Three preset values and less than the second preset value, increase the opening 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 descending order.

In a preferred embodiment of the present invention, the step of adjusting the opening degree of the auxiliary circuit electronic expansion valve 21 according to the comparison result of the degree of superheat of the auxiliary circuit and the preset value of the degree of superheat includes: a small closing step: the degree of superheat of the auxiliary circuit is less than the fourth preset value, and the first Turn down the opening degree of the electronic expansion valve 21 of the auxiliary circuit at four speeds; the superheat of the auxiliary circuit is greater than the fourth preset value and less than the fifth preset value, and the opening degree of the electronic expansion valve 21 of the auxiliary circuit is closed at the fifth speed, and the fourth preset value Less than the fifth preset value, the fourth speed is greater than the fifth speed.

In a preferred embodiment of the present invention, it also includes cyclically detecting the operating time and operating frequency of the compressor 1, detecting the operating mode of the air injection enthalpy heat pump cooling water system, detecting the outdoor ambient temperature; obtaining the exhaust superheat of the compressor 1, The superheat of the auxiliary circuit for increasing enthalpy by air injection; according to whether the detected operating time, operating frequency, operating mode, outdoor ambient temperature and exhaust superheat meet the opening or closing conditions of the electronic expansion valve 21 of the auxiliary circuit, the electronic expansion valve 21 of the auxiliary circuit is controlled to open or close. expansion valve 21, and after the auxiliary circuit electronic expansion valve 21 is opened, the opening of the auxiliary circuit electronic expansion valve 21 is adjusted according to the comparison result of the auxiliary circuit superheat and the superheat preset value, and the initial opening of the auxiliary circuit electronic expansion valve 21 is used as the The minimum opening starts to adjust.

The above are only 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 principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (8)

1. The utility model provides an enhanced vapor injection heat pump cooling water system, includes enhanced vapor injection auxiliary road, be equipped with auxiliary road electronic expansion valve on the enhanced vapor injection auxiliary road, its characterized in that, enhanced vapor injection heat pump cooling water system still includes:

the compressor operation parameter detection module is used for detecting the operation time and the operation frequency of the compressor;

the operation mode detection module is used for detecting the operation mode of the enhanced vapor injection heat pump cold water system;

an outdoor environment temperature detection module for detecting the outdoor environment temperature;

the exhaust superheat degree acquisition module is used for acquiring the exhaust superheat degree of the compressor;

the auxiliary passage superheat degree acquisition module is used for acquiring the auxiliary passage superheat degree of the enhanced vapor injection auxiliary passage;

and the control module is used for controlling the opening or closing of the auxiliary electronic expansion valve according to whether the detected running time, the running frequency, the running mode, the outdoor environment temperature and the exhaust superheat degree accord with the opening condition or the closing condition of the auxiliary electronic expansion valve, adjusting the opening of the auxiliary electronic expansion valve according to the comparison result of the auxiliary superheat degree and a preset superheat degree value after the auxiliary electronic expansion valve is opened, and starting to adjust by taking the initial opening of the auxiliary electronic expansion valve as the used minimum opening.

2. The enhanced vapor injection heat pump chilled water system of claim 1, wherein the opening conditions of the auxiliary electronic expansion valve comprise: whether the operation time is greater than a specified time threshold, the exhaust superheat degree is greater than a specified superheat degree threshold, and the operation frequency is greater than a specified frequency threshold; in the heating mode, the outdoor environment temperature is smaller than a first specified temperature threshold value, in the cooling mode, the outdoor environment temperature is larger than a second specified temperature threshold value, and the operation mode is a non-defrosting mode; and the auxiliary electronic expansion valve is opened when the opening conditions are met simultaneously, and is closed when any one of the opening conditions is not met.

3. The enhanced vapor injection heat pump cold water system according to claim 1, wherein the adjusting the opening of the auxiliary electronic expansion valve according to the comparison result of the superheat degree of the auxiliary and a preset superheat degree value comprises:

the degree of superheat of the auxiliary circuit is greater than a first preset value, and the opening of the auxiliary circuit electronic expansion valve is increased at a first speed; the degree of superheat of the auxiliary road is greater than a second preset value and smaller than the first preset value, and the opening of the auxiliary road electronic expansion valve is increased at a second speed; and the degree of superheat of the auxiliary circuit is greater than a third preset value and less than a second preset value, the opening of the auxiliary circuit electronic expansion valve is increased at a third speed, the first preset value, the second preset value and the third preset value are sequentially decreased, and the first speed, the second speed and the third speed are sequentially decreased.

4. The control method of the enhanced vapor injection heat pump cold water system according to claim 1, wherein the step of adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result of the auxiliary superheat degree and a preset superheat degree value comprises the following steps:

the degree of superheat of the auxiliary road is less than a fourth preset value, and the opening of the auxiliary road electronic expansion valve is reduced at a fourth speed; and the degree of superheat of the auxiliary road is greater than a fourth preset value and less than a fifth preset value, the opening degree of the auxiliary road electronic expansion valve is reduced 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.

5. The utility model provides a control method of enhanced vapor injection heat pump cooling water system, enhanced vapor injection heat pump cooling water system includes enhanced vapor injection auxiliary road, be equipped with auxiliary road electronic expansion valve on the enhanced vapor injection auxiliary road, its characterized in that, enhanced vapor injection heat pump cooling water system's control method includes following step:

detecting the running time and the running frequency of a compressor, detecting the running mode of a cold water system of the enhanced vapor injection heat pump, and detecting the outdoor environment temperature;

acquiring the exhaust superheat degree of a compressor and the auxiliary path superheat degree of the enhanced vapor injection auxiliary path;

and controlling to open or close the auxiliary electronic expansion valve according to whether the detected running time, the running frequency, the running mode, the outdoor environment temperature and the exhaust superheat degree accord with the opening condition or the closing condition of the auxiliary electronic expansion valve, adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result of the auxiliary superheat degree and a preset superheat degree value after the auxiliary electronic expansion valve is opened, and starting to adjust by taking the initial opening degree of the auxiliary electronic expansion valve as the used minimum opening degree.

6. The method for controlling the enhanced vapor injection heat pump cold water system according to claim 5, wherein the opening conditions of the auxiliary electronic expansion valve comprise: whether the operation time is greater than a specified time threshold, the exhaust superheat is greater than a specified superheat threshold, and the operation frequency is greater than a specified frequency threshold; in the heating mode, the outdoor environment temperature is smaller than a first specified temperature threshold value, in the cooling mode, the outdoor environment temperature is larger than a second specified temperature threshold value, and the operation mode is a non-defrosting mode; and the auxiliary electronic expansion valve is opened when the opening conditions are met at the same time, and is closed when any one opening condition is not met.

7. The control method of the enhanced vapor injection heat pump cold water system according to claim 5, wherein the adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result of the auxiliary superheat degree and a preset superheat degree comprises:

opening a big step: the degree of superheat of the auxiliary road is greater than a first preset value, and the opening degree of the auxiliary road electronic expansion valve is increased at a first speed; the degree of superheat of the auxiliary road is greater than a second preset value and smaller than the first preset value, and the opening of the auxiliary road electronic expansion valve is increased at a second speed; and the degree of superheat of the auxiliary road is greater than a third preset value and less than the second preset value, the opening degree of the auxiliary road electronic expansion valve is increased at a third speed, the first preset value, the second preset value and the third preset value are sequentially decreased, and the first speed, the second speed and the third speed are sequentially decreased.

8. The control method of the enhanced vapor injection heat pump cold water system according to claim 5, wherein the adjusting the opening degree of the auxiliary electronic expansion valve according to the comparison result of the auxiliary superheat degree and a preset superheat degree comprises:

a closing step: the degree of superheat of the auxiliary road is smaller than a fourth preset value, and the opening degree of the auxiliary road electronic expansion valve is reduced at a fourth speed; and the degree of superheat of the auxiliary circuit is greater than a fourth preset value and less than a fifth preset value, the opening of the auxiliary circuit electronic expansion valve is reduced 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.

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