A composite system and control method for air conditioning units

Abstract

This application relates to the field of heat pump technology, and discloses an air conditioning unit composite system and its control method. The air conditioning unit composite system includes an air conditioning circulation loop, a power generation circulation loop, and a control system. The control method for the air conditioning unit composite system includes: the control system receiving an operating mode command; switching a four-way reversing valve to the corresponding position according to the operating mode command; starting the air conditioning circulation loop and the power generation circulation loop; adjusting the speed of the compressor and the working fluid pump, and adjusting the power generation power of the expander, based on temperature data; determining whether the power generation power of the power generation circulation loop and the power consumption power of the air conditioning circulation loop match; if they match, maintaining the current operating parameters; if they do not match, readjusting the operating parameters. This application has the effect of saving energy and improving energy efficiency.

Description

Technical Field

[0001] This application relates to the field of heat pump technology, and in particular to an air conditioning unit composite system and control method. Background Technology

[0002] The energy efficiency rating of an air conditioning unit is greatly affected by the ambient temperature: in summer, with the cooling temperature constant, the higher the ambient temperature, the lower the energy efficiency rating of the air conditioning unit; in winter, with the heating temperature constant, the lower the ambient temperature, the lower the energy efficiency rating of the air conditioning unit.

[0003] Common measures to improve the energy efficiency of air conditioning units include increasing the aerodynamic efficiency of the compressor, increasing the heat exchanger area, and changing the circulating refrigerant. However, these measures are technically difficult, have high production costs, and offer limited improvement in energy efficiency. They are all unable to overcome the negative impact of extreme ambient temperatures on energy efficiency. Summary of the Invention

[0004] In order to save energy and improve energy efficiency, this application provides a combined air conditioning unit system and control method.

[0005] The technical solution of the air conditioning unit composite system and control method provided in this application is as follows:

[0006] An air conditioning unit composite system includes an air conditioning circulation loop, a power generation circulation loop, and a control system, wherein:

[0007] The air conditioning circulation loop includes a compressor, an indoor air-cooled heat exchanger, and a plate heat exchanger.

[0008] The power generation cycle includes an expander, an outdoor air-cooled heat exchanger, a working fluid pump, and a plate heat exchanger.

[0009] The air conditioning circulation loop and the power generation circulation loop share the plate heat exchanger;

[0010] The low-temperature water inlet of the plate heat exchanger is connected to an underground water source;

[0011] The air conditioning circulation loop and the power generation circulation loop are equipped with multiple four-way reversing valves connected to the control system.

[0012] The air conditioning circulation loop and the power generation circulation loop operate in parallel, and the power generation circulation loop outputs electrical energy to compensate for the losses in the air conditioning circulation loop.

[0013] Optionally, when in heating mode, the working fluid in the air conditioning circulation loop circulates sequentially through the plate heat exchanger, compressor, indoor air-cooled heat exchanger, and plate heat exchanger.

[0014] The groundwater source in the plate heat exchanger heats the working fluid flowing through the plate heat exchanger in the air conditioning circulation loop and forms a superheated gaseous working fluid.

[0015] The compressor compresses the superheated gas into a high-temperature, high-pressure gaseous working fluid.

[0016] The indoor air-cooled heat exchanger condenses the high-temperature, high-pressure gaseous working fluid, releasing heat to form a liquid working fluid.

[0017] The liquid working fluid is depressurized and refluxed back to the plate heat exchanger.

[0018] Optionally, the working fluid in the power generation circulation loop circulates sequentially through the plate heat exchanger, expander, outdoor air-cooled heat exchanger, working fluid pump, and plate heat exchanger.

[0019] The groundwater source in the plate heat exchanger heats the working fluid flowing through the plate heat exchanger in the power generation circulation loop and forms a superheated gaseous working fluid.

[0020] The expander generates electricity under the action of a superheated gaseous working fluid.

[0021] The outdoor air-cooled heat exchanger condenses the superheated gaseous working fluid into a liquid working fluid.

[0022] The liquid working fluid is pressurized and refluxed back into the plate heat exchanger.

[0023] Optionally, when in cooling mode, the working fluid in the air conditioning circulation loop circulates sequentially between the plate heat exchanger, the indoor air-cooled heat exchanger, the compressor, and the plate heat exchanger.

[0024] The groundwater source in the plate heat exchanger cools the superheated gaseous working fluid flowing through the plate heat exchanger in the air conditioning circulation loop into a liquid working fluid.

[0025] The liquid working fluid is depressurized and flows into the indoor air-cooled heat exchanger to evaporate and absorb heat;

[0026] The compressor compresses the gaseous working fluid into a high-temperature, high-pressure gaseous working fluid.

[0027] Optionally, the working fluid in the power generation cycle loop circulates between the plate heat exchanger, the working fluid pump, the outdoor air-cooled heat exchanger, the expander, and the plate heat exchanger.

[0028] The groundwater source in the plate heat exchanger cools the superheated gaseous working fluid flowing through the plate heat exchanger in the power generation circulation loop into a liquid working fluid.

[0029] The working fluid pump pressurizes and delivers the liquid working fluid to the outdoor air-cooled heat exchanger, where it evaporates to form a high-pressure gaseous working fluid.

[0030] After the high-pressure gaseous working fluid is used to generate electricity in the expander, it flows back to the plate heat exchanger for cooling.

[0031] Optionally, the working fluid in the air conditioning circulation loop and the power generation circulation loop is the same.

[0032] A control method for a combined air conditioning unit system, the control method comprising:

[0033] The control system receives operating mode commands;

[0034] Switch the four-way directional valve to the corresponding position according to the operating mode command;

[0035] Start the air conditioning circulation loop and the power generation circulation loop, and monitor the groundwater temperature, indoor ambient temperature, indoor set temperature and outdoor ambient temperature;

[0036] Based on temperature data, the speed of the compressor and working fluid pump is adjusted through the control system, and the power generation of the expander is also adjusted.

[0037] Determine whether the power generation of the generator loop and the power consumption of the air conditioning loop match. If they match, maintain the current operating parameters; otherwise, readjust the operating parameters.

[0038] Optionally, when the air conditioning circulation loop is in heating mode:

[0039] Each time the indoor ambient temperature exceeds the target temperature by 0.5℃, the compressor speed decreases by 5Hz until it reaches the minimum speed.

[0040] Each time the indoor ambient temperature is detected to be 0.5℃ lower than the target temperature, the compressor speed increases by 5Hz until it reaches the maximum speed;

[0041] When the air conditioner's circulation loop is in cooling mode:

[0042] Each time the indoor ambient temperature is detected to be 0.5℃ lower than the target temperature, the compressor speed is reduced by 5Hz until it reaches the minimum speed.

[0043] Each time the indoor ambient temperature exceeds the target temperature by 0.5℃, the compressor speed increases by 5Hz until it reaches the maximum speed.

[0044] Optionally, when the power generation cycle loop is in heating mode:

[0045] Each time the power generation is detected to be 0.5 kW greater than the rated power, the working fluid pump speed is reduced by 1 Hz until the minimum speed is reached;

[0046] Each time the power generation is detected to be 0.5 kW lower than the rated power, the working fluid pump speed is increased by 1 Hz until the maximum speed is reached.

[0047] In summary, this application includes at least one of the following beneficial technical effects:

[0048] 1. The air conditioning circulation loop and the power generation circulation loop share the same plate heat exchanger, allowing the stable heat or cooling capacity of the groundwater source to be utilized in both directions: in heating mode, the ground source heats the working fluid to form a superheated gaseous state, reducing compressor energy consumption; in cooling mode, the ground source cools the working fluid, reducing the compression load. Simultaneously, the power generation circulation loop recovers waste heat or cooling pressure differential from the air conditioning loop to generate electricity, converting energy that might otherwise be lost into electrical energy, directly compensating for the operating losses of the air conditioning system, thereby reducing the input demand on the external power grid.

[0049] 2. Through the coordinated control of the four-way valve and the expansion valve, rapid switching of operating modes and precise matching of dynamic loads are achieved, enhancing the system's response speed and operational stability. Based on real-time temperature feedback, the control system adjusts the compressor speed and expansion valve opening in stages to prevent equipment damage due to sudden load changes.

[0050] 3. Because the air conditioning and power generation circulation loops use the same working fluid, compatibility issues between different working fluids are reduced, and the types and complexity of seals, pipes, and valves are decreased. The flow rate of groundwater is independently regulated through the groundwater inlet valve of the evaporator, which avoids resource waste caused by excessive water extraction, reduces water pump energy consumption, and reduces the manpower and material investment in initial installation and subsequent maintenance. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the heating mode system according to an embodiment of this application.

[0052] Figure 2 This is a schematic diagram of the cooling mode system in an embodiment of this application.

[0053] Figure 3 This is a flowchart of the heating mode control system in an embodiment of this application.

[0054] Figure 4 This is a flowchart of the heat pump circuit control in the heating mode in the embodiments of this application.

[0055] Figure 5 This is a flowchart of the power generation circuit control in the heating mode in the embodiments of this application.

[0056] Figure 6 This is a flowchart of the cooling mode control system in an embodiment of this application.

[0057] Figure 7 This is a flowchart of the heat pump circuit control in cooling mode in the embodiments of this application.

[0058] Figure 8 This is a flowchart of the cooling mode power generation circuit control in the embodiments of this application.

[0059] Marker explanation:

[0060] T101, Ground source water inlet temperature sensor;

[0061] T102, Ground source water outlet temperature sensor;

[0062] T201, Expander inlet temperature sensor;

[0063] T202, compressor inlet temperature sensor;

[0064] T301, Outdoor air heat exchanger temperature sensor;

[0065] T302, Outdoor air heat exchange temperature sensor;

[0066] T401, Indoor air heat exchanger temperature sensor;

[0067] T402, Indoor air heat exchange temperature sensor;

[0068] P201, Expander inlet pressure sensor;

[0069] P202, Compressor inlet pressure sensor;

[0070] Ev101, Ground source water inlet valve for evaporator;

[0071] Ev201, First expansion valve (expander inlet V-shaped pneumatic ball valve);

[0072] Ev202, Second expansion valve (compressor inlet V-shaped pneumatic ball valve);

[0073] Ev203, Third Expansion Valve (Electronic Expansion Valve for Heat Pump Circulation Loop);

[0074] Ev204, First four-way valve (heat pump circulation loop four-way reversing valve).

[0075] Ev205, Second Four-Way Valve (Power Generation Circulation Circuit Four-Way Reversing Valve).

[0076] Ev206, Third Four-Way Valve (Four-Way Reversing Valve for Working Fluid Pump Circulation Circuit). Detailed Implementation

[0077] The following is in conjunction with the appendix Figures 1-8 This application will be described in further detail.

[0078] This application discloses an air conditioning unit composite system.

[0079] An air conditioning unit composite system includes an air conditioning circulation loop, a power generation circulation loop, and a control system. The air conditioning circulation loop includes a compressor, an indoor air-cooled heat exchanger (i.e., a high-temperature condenser), and a plate heat exchanger (i.e., an evaporator). The power generation circulation loop includes an expander, an outdoor air-cooled heat exchanger (i.e., a low-temperature condenser), a working fluid pump, and a plate heat exchanger (i.e., an evaporator). The plate heat exchanger (i.e., the evaporator) is used as a shared component by both the air conditioning circulation loop and the power generation circulation loop, and is connected to an underground water source to achieve efficient heat exchange. This design reduces heat loss and improves the overall heat recovery rate.

[0080] The air conditioning circulation loop and the power generation circulation loop are equipped with multiple four-way reversing valves connected to the control system to flexibly switch the working fluid flow path. The air conditioning circulation loop and the power generation circulation loop operate in parallel. The power output of the power generation circulation loop directly compensates for the losses in the air conditioning circulation loop, thereby improving the overall system efficiency and reducing grid dependence. In this embodiment, the working fluid is R410a.

[0081] When in heating mode, the working fluid in the air conditioning circulation loop circulates sequentially through the plate heat exchanger (evaporator), compressor, indoor air-cooled heat exchanger (high-temperature condenser), and plate heat exchanger (evaporator). The groundwater source in the plate heat exchanger (evaporator) heats the working fluid flowing through it and forms a superheated gaseous working fluid. The temperature of the groundwater before entering the evaporator is measured by the groundwater inlet temperature sensor (T101), and the valve opening is adjusted in real time according to the air conditioning load and power generation requirements by the groundwater inlet valve (Ev101). The temperature of the groundwater after heat exchange in the evaporator is measured by the groundwater outlet temperature sensor (T102).

[0082] The compressor compresses superheated gas into a high-temperature, high-pressure gaseous working fluid. Before the superheated gas enters the compressor, the temperature of the low-boiling-point circulating working fluid before entering the compressor is measured by the compressor inlet temperature sensor (T202), and the pressure of the low-boiling-point circulating working fluid before entering the compressor is measured by the compressor inlet pressure sensor (P202). The indoor air-cooled heat exchanger (i.e., the high-temperature condenser) condenses the high-temperature, high-pressure gaseous working fluid, releasing heat to form a liquid working fluid. During the operation of the indoor air-cooled heat exchanger (i.e., the high-temperature condenser), the temperature of the outdoor air before entering the low-temperature condenser is measured by the indoor air pre-heat exchange temperature sensor (T401), and the temperature of the indoor air after passing through the high-temperature condenser is measured by the indoor air post-heat exchange temperature sensor (T402). The liquid working fluid is depressurized and flows back to the plate heat exchanger (i.e., the evaporator). This process utilizes the stable heat source of underground water, significantly improving heating efficiency and working fluid superheat, reducing compressor energy consumption, and avoiding temperature fluctuations.

[0083] Meanwhile, the working fluid in the power generation circulation loop circulates sequentially through the plate heat exchanger (i.e., evaporator), expander, outdoor air-cooled heat exchanger (i.e., low-temperature condenser), working fluid pump, and plate heat exchanger (i.e., evaporator). The groundwater source in the plate heat exchanger (i.e., evaporator) heats the working fluid flowing through the plate heat exchanger (i.e., evaporator) in the power generation circulation loop, forming a superheated gaseous working fluid. The temperature of the groundwater before entering the evaporator is measured by the groundwater inlet temperature sensor (i.e., T101), and the valve opening is adjusted in real time according to the air conditioning load and power generation demand by the groundwater inlet valve (i.e., Ev101). The temperature of the groundwater after heat exchange in the evaporator is measured by the groundwater outlet temperature sensor (i.e., T102).

[0084] The expander generates electricity under the action of superheated gaseous working fluid. Before the superheated gaseous working fluid enters the expander, the temperature of the low-boiling-point circulating working fluid before entering the expander is measured by the expander inlet temperature sensor (T201), and the pressure of the low-boiling-point circulating medium before entering the expander is measured by the expander inlet pressure sensor (P201). The superheated gaseous working fluid condenses into liquid working fluid in the outdoor air-cooled heat exchanger (i.e., low-temperature condenser). During the operation of the outdoor air-cooled heat exchanger (i.e., low-temperature condenser), the temperature of the outdoor air before entering the low-temperature condenser is measured by the outdoor air pre-heat exchange temperature sensor (T301), and the temperature of the outdoor air after passing through the low-temperature condenser is measured by the outdoor air post-heat exchange temperature sensor (T302). The liquid working fluid is pressurized and flows back to the plate heat exchanger (i.e., evaporator). This design recovers the waste heat of the air conditioning circuit for power generation, compensates for air conditioning losses, realizes energy reuse, reduces the total power consumption of the system, and improves the stability of power generation output through waste heat conversion.

[0085] When in cooling mode, the working fluid in the air conditioning circulation loop circulates sequentially between the plate heat exchanger (evaporator), the indoor air-cooled heat exchanger (high-temperature condenser), the compressor, and the plate heat exchanger (evaporator). The groundwater source in the plate heat exchanger (evaporator) cools the superheated gaseous working fluid flowing through it into a liquid state. The liquid working fluid is depressurized and flows to the indoor air-cooled heat exchanger (high-temperature condenser) to evaporate and absorb heat. The compressor compresses the gaseous working fluid into a high-temperature, high-pressure gaseous working fluid. The low-temperature characteristics of the groundwater source effectively cool the working fluid, reduce the compression load, improve cooling efficiency, and ensure rapid cooling response.

[0086] In the power generation cycle, the working fluid circulates between the plate heat exchanger (evaporator), the working fluid pump, the outdoor air-cooled heat exchanger (low-temperature condenser), the expander, and the plate heat exchanger (evaporator). The groundwater source in the plate heat exchanger (evaporator) cools the superheated gaseous working fluid flowing through the plate heat exchanger (evaporator) into a liquid working fluid. The working fluid pump pressurizes the liquid working fluid and delivers it to the outdoor air-cooled heat exchanger (low-temperature condenser) for evaporation to form a high-pressure gaseous working fluid. After generating electricity, the high-pressure gaseous working fluid expands and then flows back to the plate heat exchanger (evaporator) for cooling. This mode utilizes the pressure difference during the cooling process to generate electricity, recovers waste heat and converts it into electrical energy, further compensates for air conditioning energy consumption, enhances system economy, and optimizes the working fluid state transition process.

[0087] The air conditioning circulation loop and the power generation circulation loop use the same working fluid, which simplifies system design and ensures thermodynamic compatibility, reduces maintenance costs, and avoids working fluid mixing losses. The control system optimizes mode switching through a four-way reversing valve, improves response speed and stability, and ensures efficient system operation under dynamic loads. Overall, the shared plate heat exchanger (i.e., evaporator) and groundwater source achieve efficient heat recovery, significantly improving the energy efficiency ratio. The power generation compensation mechanism reduces grid dependence and expands the system's application scenarios to various environments.

[0088] To facilitate the regulation of the working fluid flow through the expander, compressor, indoor air-cooled heat exchanger (i.e., high-temperature condenser), and plate heat exchanger (i.e., evaporator), the working fluid is connected to the expander through the first expansion valve (i.e., Ev201), to the compressor through the second expansion valve (i.e., Ev202), and to the indoor air-cooled heat exchanger (i.e., high-temperature condenser) through the third expansion valve (i.e., Ev203). This configuration allows for precise control of the working fluid flow rate and pressure, preventing equipment overload and optimizing heat exchange efficiency, based on the principle that flow regulation can match load changes and reduce ineffective energy consumption.

[0089] To control the flow rate of groundwater through the plate heat exchanger (i.e., evaporator), the groundwater source is connected to the plate heat exchanger (i.e., evaporator) through the groundwater inlet valve. This ensures that the groundwater input is synchronized with the heat demand, avoids resource waste, and improves the heat recovery rate. The basis for this is that optimizing the water flow rate can maintain a stable temperature gradient.

[0090] To facilitate control of the working fluid flow, the four-way valve includes a first four-way valve (Ev204), a second four-way valve (Ev205), and a third four-way valve (Ev206). These valves work together to achieve rapid path switching.

[0091] The first four-way valve (i.e., Ev204) is located between the plate heat exchanger (i.e., evaporator) and the indoor air-cooled heat exchanger (i.e., high-temperature condenser), and connects the plate heat exchanger (i.e., evaporator) and the indoor air-cooled heat exchanger (i.e., high-temperature condenser). The compressor, the first four-way valve (i.e., Ev204), and the second expansion valve (i.e., Ev202) form a circulation loop. This structure ensures seamless flow of the working fluid in heating or cooling modes, reduces pressure drop loss, and improves indoor heat exchange efficiency. This is based on path optimization to shorten response time.

[0092] The second four-way valve (Ev205) is located between the plate heat exchanger (evaporator) and the outdoor air-cooled heat exchanger (low-temperature condenser), and connects the plate heat exchanger (evaporator) and the outdoor air-cooled heat exchanger (low-temperature condenser). The expander, the second four-way valve (Ev205) and the first expansion valve (Ev201) form a circulation loop, which provides flexible flow control, enhances the adaptability of the power generation circuit, and avoids working fluid stagnation, based on reducing energy loss during mode switching.

[0093] The third four-way valve (i.e., Ev206) is located between the plate heat exchanger (i.e., evaporator) and the working fluid pump, and connects the plate heat exchanger (i.e., evaporator) and the working fluid pump. The working fluid pump and the third four-way valve (i.e., Ev206) form a circulation loop. This design stabilizes the working fluid delivery pressure, ensures maximum pump efficiency and extends equipment life, based on the principle that closed-loop circuits reduce fluctuations.

[0094] The implementation principle of the air conditioning unit composite system in this application embodiment is as follows: In heating mode, the working fluid in the air conditioning circulation loop flows sequentially through the plate heat exchanger (i.e., evaporator) and is heated into a superheated gas by the groundwater source. It is then compressed into a high-temperature and high-pressure gas by the compressor. After condensing and releasing heat into a liquid state in the indoor air-cooled heat exchanger (i.e., high-temperature condenser), it is depressurized and flows back to the plate heat exchanger (i.e., evaporator). At the same time, the working fluid in the power generation circulation loop also flows sequentially through the plate heat exchanger (i.e., evaporator) and is heated into a superheated gas state by the groundwater source. It drives the expander to generate electricity. After condensing into a liquid state in the outdoor air-cooled heat exchanger (i.e., low-temperature condenser), it is pressurized by the working fluid pump and flows back to the plate heat exchanger (i.e., evaporator), thereby realizing waste heat recovery and directly compensating for air conditioning losses.

[0095] In cooling mode, the working fluid in the air conditioning circulation loop is cooled into a liquid state by the groundwater source in the plate heat exchanger (i.e., evaporator), then evaporates and absorbs heat in the indoor air-cooled heat exchanger (i.e., high-temperature condenser) after being depressurized, and finally compressed into a high-temperature and high-pressure gas by the compressor and flows back to the plate heat exchanger (i.e., evaporator).

[0096] The working fluid in the power generation cycle is cooled into a liquid state in the plate heat exchanger (i.e., evaporator), pressurized by the working fluid pump and sent to the outdoor air-cooled heat exchanger (i.e., low-temperature condenser) to evaporate into a high-pressure gas state. After driving the expander to generate electricity, it flows back to the plate heat exchanger (i.e., evaporator) to continue cooling. The pressure difference during the cooling process generates electricity to further compensate for the air conditioning energy consumption. Throughout the process, the control system achieves precise flow and direction control of the working fluid between the compressor, expander, indoor air-cooled heat exchanger (i.e., high-temperature condenser), outdoor air-cooled heat exchanger (i.e., low-temperature condenser), plate heat exchanger (i.e., evaporator), and groundwater source through the coordinated regulation of the first four-way valve (i.e., Ev204), the second four-way valve (i.e., Ev205), the third four-way valve (i.e., Ev206), the first expansion valve (i.e., Ev201), the second expansion valve (i.e., Ev202), the third expansion valve (i.e., Ev203), and the groundwater source valve. This ensures high energy efficiency, fast response, and low grid dependence during the parallel operation of air conditioning and power generation.

[0097] A control method for a combined air conditioning unit system, the control method comprising:

[0098] S1. The control system receives the operating mode command and initiates the system initialization process;

[0099] S2. Switch the four-way directional valve to the corresponding position according to the operating mode command to ensure that the working fluid flow path accurately matches the mode requirements;

[0100] S3. Simultaneously start the air conditioning circulation loop and the power generation circulation loop, and monitor the groundwater temperature, indoor ambient temperature, indoor set temperature and outdoor ambient temperature in real time to build a multi-parameter feedback network.

[0101] S4. Based on dynamic analysis of temperature data, the speed of the compressor and working fluid pump is adjusted by the control system to achieve load matching, and the power generation of the expander is adjusted in conjunction to optimize energy conversion efficiency.

[0102] S5. Continuously judge the balance between the power generation of the power generation loop and the power consumption of the air conditioning loop. If they match, maintain the current operating parameters to ensure steady-state operation. If they do not match, readjust the operating parameters to eliminate the energy deviation.

[0103] When the air conditioner's circulation loop is in heating mode:

[0104] Each time the indoor ambient temperature exceeds the target temperature by 0.5℃, the compressor speed is reduced in a 5Hz gradient until the minimum speed is reached. This step-by-step speed reduction strategy avoids temperature overshoot. After the compressor reaches the minimum speed, the opening of the second expansion valve (i.e., Ev202) is gradually reduced to a reasonable range. The throttling effect further suppresses the heating output, maintains temperature stability, and reduces energy consumption.

[0105] Each time the indoor ambient temperature is detected to be 0.5℃ lower than the target temperature, the opening of the second expansion valve (i.e., Ev202) is increased in a 5% gradient to 100% to fully release the working fluid flow potential. After the valve is fully open, the compressor speed is increased in a 5Hz gradient until the maximum speed. This phased adjustment strategy avoids sudden load changes in the equipment and extends the compressor life.

[0106] Each time the indoor ambient temperature is within the range of ±0.5℃ of the target value, the opening of the second expansion valve (i.e., Ev202) is gradually increased to 100% in a 5% increment. This preventive adjustment provides a reserve of adjustment margin in advance, enhancing the system's anti-interference capability.

[0107] When the air conditioner's circulation loop is in cooling mode:

[0108] Each time the indoor ambient temperature is detected to be 0.5℃ lower than the target temperature, the compressor speed is reduced to the minimum speed in a 5Hz gradient to match the decrease in cooling demand. When the compressor reaches the minimum speed, the opening of the second expansion valve (i.e., Ev202) is reduced by 5%, and the dual regulation mechanism accurately suppresses the overcooling phenomenon.

[0109] Each time the indoor ambient temperature is detected to be 0.5℃ higher than the target temperature, the opening of the second expansion valve (i.e., Ev202) is increased to 100% in a 5% gradient to improve the working fluid evaporation efficiency. After the valve is fully open, the compressor speed is increased to the maximum speed in a 5Hz gradient, and the step-by-step pressurization ensures a rapid cooling response.

[0110] Each time the indoor ambient temperature is within ±0.5℃ of the target value, the opening of the second expansion valve (i.e., Ev202) increases by 5% to maintain dynamic balance and prevent frequent start-stop cycles caused by temperature fluctuations.

[0111] When the power generation cycle is in heating mode:

[0112] Each time the power generation is greater than or equal to the rated power of 0.5 kW, the working fluid pump speed is reduced to the minimum speed in a 1 Hz gradient to reduce the working fluid delivery. After the working fluid pump reaches the minimum speed, if the target heating temperature is greater than the maximum heating temperature, the opening of the ground source water inlet valve to the evaporator is reduced by 10% to limit the input of ground source heat. Conversely, the target heating temperature is increased by 0.5℃ (manual confirmation required). This graded strategy prioritizes the stability of power generation and prevents equipment overheating.

[0113] Each time the power generation is detected to be 0.5 kW lower than the rated power, the working fluid pump speed is increased to the maximum speed in a 1 Hz gradient to maximize the working fluid circulation rate and enhance the power generation output.

[0114] Each time the power generation is within ±0.5kW of the target value, the current speed of the working fluid pump is maintained to ensure steady-state operation of the power generation circuit.

[0115] When the power generation cycle is in cooling mode:

[0116] Each time the power generation is greater than or equal to the rated power of 0.5 kW, the working fluid pump speed is reduced to the minimum speed in a 1 Hz gradient to reduce the working fluid delivery. After the working fluid pump reaches the minimum speed, if the target cooling temperature is less than the minimum cooling temperature, the opening of the ground source water inlet valve to the evaporator is reduced by 10% to limit the input of ground source heat. If the target cooling temperature is not less than the minimum cooling temperature, the target cooling temperature is reduced by 0.5℃ (manual confirmation required).

[0117] Each time the power generation is detected to be 0.5 kW lower than the rated power, the working fluid pump speed is increased to the maximum speed in a 1 Hz gradient to maximize the working fluid circulation rate and enhance the power generation output.

[0118] Each time the power generation is within the range of ±0.5kW of the rated power, the current speed of the working fluid pump is maintained to ensure steady-state operation of the power generation circuit.

[0119] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A combined air conditioning unit system, characterized in that: It includes an air conditioning circulation loop, a power generation circulation loop, and a control system, wherein: The air conditioning circulation loop includes a compressor, an indoor air-cooled heat exchanger, and a plate heat exchanger. The power generation cycle includes an expander, an outdoor air-cooled heat exchanger, a working fluid pump, and a plate heat exchanger. The air conditioning circulation loop and the power generation circulation loop share the plate heat exchanger; The low-temperature water inlet of the plate heat exchanger is connected to an underground water source; The air conditioning circulation loop and the power generation circulation loop are equipped with multiple four-way reversing valves connected to the control system. The air conditioning circulation loop and the power generation circulation loop operate in parallel, and the power generation circulation loop outputs electrical energy to compensate for the losses in the air conditioning circulation loop.

2. The air conditioning unit composite system according to claim 1, characterized in that: When in heating mode, the working fluid in the air conditioning circulation loop circulates sequentially through the plate heat exchanger, compressor, indoor air-cooled heat exchanger, and plate heat exchanger. The groundwater source in the plate heat exchanger heats the working fluid flowing through the plate heat exchanger in the air conditioning circulation loop and forms a superheated gaseous working fluid. The compressor compresses the superheated gas into a high-temperature, high-pressure gaseous working fluid. The indoor air-cooled heat exchanger condenses the high-temperature, high-pressure gaseous working fluid, releasing heat to form a liquid working fluid. The liquid working fluid is depressurized and refluxed back to the plate heat exchanger.

3. The air conditioning unit composite system according to claim 2, characterized in that: The working fluid in the power generation cycle loop circulates sequentially through the plate heat exchanger, expander, outdoor air-cooled heat exchanger, working fluid pump, and plate heat exchanger. The groundwater source in the plate heat exchanger heats the working fluid flowing through the plate heat exchanger in the power generation circulation loop and forms a superheated gaseous working fluid. The expander generates electricity under the action of a superheated gaseous working fluid. The outdoor air-cooled heat exchanger condenses the superheated gaseous working fluid into a liquid working fluid. The liquid working fluid is pressurized and refluxed back into the plate heat exchanger.

4. The air conditioning unit composite system according to claim 1, characterized in that: When in cooling mode, the working fluid in the air conditioning circulation loop circulates sequentially between the plate heat exchanger, the indoor air-cooled heat exchanger, the compressor, and the plate heat exchanger. The groundwater source in the plate heat exchanger cools the superheated gaseous working fluid flowing through the plate heat exchanger in the air conditioning circulation loop into a liquid working fluid. The liquid working fluid is depressurized and flows into the indoor air-cooled heat exchanger to evaporate and absorb heat; The compressor compresses the gaseous working fluid into a high-temperature, high-pressure gaseous working fluid.

5. The air conditioning unit composite system according to claim 4, characterized in that: The working fluid in the power generation cycle loop circulates between the plate heat exchanger, the working fluid pump, the outdoor air-cooled heat exchanger, the expander, and the plate heat exchanger. The groundwater source in the plate heat exchanger cools the superheated gaseous working fluid flowing through the plate heat exchanger in the power generation circulation loop into a liquid working fluid. The working fluid pump pressurizes and delivers the liquid working fluid to the outdoor air-cooled heat exchanger, where it evaporates to form a high-pressure gaseous working fluid. After the high-pressure gaseous working fluid is used to generate electricity in the expander, it flows back to the plate heat exchanger for cooling.

6. The air conditioning unit composite system according to claim 1, characterized in that: The working fluid used in both the air conditioning circulation loop and the power generation circulation loop is the same.

7. A control method for an air conditioning unit composite system, wherein the control method is applied to an air conditioning unit composite system according to any one of claims 1-6, characterized in that: The control method includes: The control system receives operating mode commands; Switch the four-way directional valve to the corresponding position according to the operating mode command; Start the air conditioning circulation loop and the power generation circulation loop, and monitor the groundwater temperature, indoor ambient temperature, indoor set temperature and outdoor ambient temperature; Based on temperature data, the speed of the compressor and working fluid pump is adjusted through the control system, and the power generation of the expander is also adjusted. Determine whether the power generation of the generator loop and the power consumption of the air conditioning loop match. If they match, maintain the current operating parameters; otherwise, readjust the operating parameters.

8. The control method for a composite system of an air conditioning unit according to claim 7, characterized in that: When the air conditioner's circulation loop is in heating mode: Each time the indoor ambient temperature exceeds the target temperature by 0.5℃, the compressor speed decreases by 5Hz until it reaches the minimum speed. Each time the indoor ambient temperature is detected to be 0.5℃ lower than the target temperature, the compressor speed increases by 5Hz until it reaches the maximum speed; When the air conditioner's circulation loop is in cooling mode: Each time the indoor ambient temperature is detected to be 0.5℃ lower than the target temperature, the compressor speed is reduced by 5Hz until it reaches the minimum speed. Each time the indoor ambient temperature exceeds the target temperature by 0.5℃, the compressor speed increases by 5Hz until it reaches the maximum speed.

9. The control method for a combined air conditioning unit system according to claim 7, characterized in that: When the power generation cycle loop is in heating mode: Each time the power generation is detected to be 0.5 kW greater than the rated power, the working fluid pump speed is reduced by 1 Hz until the minimum speed is reached; Each time the power generation is detected to be 0.5 kW lower than the rated power, the working fluid pump speed is increased by 1 Hz until the maximum speed is reached.

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