Novel heating and hot water combined supply system and control method

Abstract

According to the novel heating and hot water combined supply system and the control method, the core key component is the double-temperature-zone plate type heat exchanger, hot water and a high-temperature refrigerant exchange heat in the heat exchanger, hot water or heating is conducted, and hot water heating and heating can also be achieved at the same time. For the hot water operation mode and the heating operation mode, a hot water temperature set value and a return water temperature set value are adopted as control targets to adjust the operation frequency of a compressor, and for the hot water and heating mode, the maximum value of the hot water temperature set value and the return water temperature set value is adopted as a target to control the operation frequency of the compressor. A water mixing proportion three-way valve is arranged between a heating water outlet pipe and a water return pipe, and when a hot water mode and a heating mode operate simultaneously and a hot water temperature set value serves as a control target, the three-way valve is adopted to adjust the heating water return temperature. Compared with a conventional heating, hot water and heat pump dual-combined supply unit, the unit is simple in structure, low in cost, capable of meeting the requirements for water heating and heating at the same time, free of shutdown switching and stable and reliable in operation.

Description

Technical Field

[0001] This invention relates to air source heat pump systems, and more specifically, to a novel dual-supply system for heating and hot water and its control method. Background Technology

[0002] With rapid economic development and the continuous improvement of people's living standards, the demand for heating equipment and water heaters is showing a rapid growth trend. Heat pump units, due to their mature technology, high comfort, and energy-saving and environmentally friendly characteristics, are gradually replacing traditional electric water heaters and coal-fired boilers, becoming the mainstream in the market. Currently, common heat pump products on the market mainly include air source water heaters and heating heat pumps, but these products have limited functions, only meeting domestic hot water or heating needs respectively. To simultaneously supply heating and domestic hot water, users usually need to install two independent systems. This not only increases purchase and installation costs but also leads to compatibility issues due to potential brand differences and occupies significant installation space.

[0003] To address these issues, multi-functional heat pumps have emerged, designed to simultaneously provide domestic hot water and heating. However, existing multi-functional heat pumps on the market still have significant drawbacks. For example, switching between domestic hot water and heating hot water typically relies on an electric three-way valve for mode conversion, meaning that hot water production and heating operation cannot occur simultaneously. To compensate for this deficiency, some products increase the tank volume to store hot water produced during the day to meet nighttime needs, but this method requires significant space and is particularly unsuitable for the dual-supply needs of ordinary domestic residences. Furthermore, existing dual-supply heat pump products generally use a water-to-water heat exchange design for their insulated water tanks, where heating water pipes are wrapped around the outer wall of the inner tank, and the water in the pipes heats the water in the tank. This design has low heat exchange efficiency, long heating time, and low energy efficiency, making it difficult to meet users' actual needs. Summary of the Invention

[0004] In view of this, in order to overcome the above-mentioned technical defects, the present invention proposes a novel dual-supply system for heating and hot water and a control method. The system uses a dual-temperature zone plate heat exchanger as the core component, and combines the integrated design of the heat pump host module, the heating water circulation system and the hot water circulation system to realize the function of simultaneously producing domestic hot water and heating, without the need to stop the machine to switch operating modes.

[0005] To achieve the above technical advantages, the technical solution of the present invention is as follows: A novel combined heating and hot water supply system includes a heat pump main unit module, a heating module, and a hot water module; the heat pump main unit module includes a variable frequency compressor, an oil separator, a four-way valve, a dual-temperature zone plate heat exchanger, an electronic expansion valve, an outdoor heat exchanger, and a gas-liquid separator connected in sequence, forming a refrigerant circulation main loop; The dual-temperature zone plate heat exchanger is provided with a heating heat exchange channel and a hot water heat exchange channel. The heating heat exchange channel is connected to the heating module, and the hot water heat exchange channel is connected to the hot water module. The heating heat exchange channel and the hot water heat exchange channel are respectively supplied with hot water, so that the heating module and the hot water module can exchange heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger independently or synchronously.

[0006] Furthermore, the heating module includes a hot water return pipe, a hot water outlet pipe, a proportional three-way valve, a heating water pump, and a buffer tank. The hot water return pipe and the hot water outlet pipe are respectively connected to the heating heat exchange channel. The heating water pump is installed on the hot water return pipe. The proportional three-way valve includes an a port, a b port, and an f port. The a port and b port of the proportional three-way valve are connected to the hot water return pipe, and the f port of the proportional three-way valve is connected to the hot water outlet pipe via the buffer tank. The proportional three-way valve adjusts the proportion of hot water flowing through the heating heat exchange channel and the buffer tank by adjusting the proportion of hot water flowing from the a port to the b port and the f port.

[0007] Furthermore, the hot water module includes a hot water tank and a hot water pump. The hot water tank is connected to the hot water heat exchange channel through a hot water circulation pipeline to form a hot water circulation loop. The hot water pump drives the hot water to circulate between the hot water tank and the dual-temperature zone plate heat exchanger, so that the hot water exchanges heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger.

[0008] Furthermore, the exhaust pipe of the variable frequency compressor is connected to the d-pipe of the four-way valve via an oil separator. The e-pipe of the four-way valve is connected to the inlet pipe of the dual-temperature zone plate heat exchanger via the main gas pipe. The liquid outlet pipe of the dual-temperature zone plate heat exchanger is connected to one end of the electronic expansion valve via the main liquid pipe. The other end of the electronic expansion valve is connected to one end of the outdoor heat exchanger. The other end of the outdoor heat exchanger is connected to the c-pipe of the four-way valve. The s-pipe of the four-way valve is connected to the inlet pipe of the gas-liquid separator. The outlet pipe of the gas-liquid separator is connected to the return gas pipe of the variable frequency compressor.

[0009] Furthermore, it also includes a temperature detection module, which comprises an exhaust temperature sensor, an ambient temperature sensor, a coil temperature sensor, a return air temperature sensor, a return water temperature sensor, an outlet water temperature sensor, and a hot water temperature sensor. The exhaust temperature sensor is used to detect the exhaust temperature T. d The ambient temperature sensor is used to detect the ambient temperature T. ao The coil temperature sensor is used to detect the coil temperature T. def The return gas temperature sensor is used to detect the return gas temperature T. s The return water temperature sensor is used to detect the return water temperature T. w,in The outlet water temperature sensor is used to detect the outlet water temperature T of the hot water flowing out of the heating heat exchange channel.w,out The hot water temperature sensor is used to detect the temperature T of the hot water in the hot water tank. tank .

[0010] A novel control method for a combined heating and hot water supply system, the method comprising heating start-up conditions, hot water start-up conditions, and heating + hot water operation start-up conditions. If the preset heating start-up conditions are met, the system enters heating operation control, allowing the heating module to exchange heat with the refrigerant flowing through the dual-temperature-zone plate heat exchanger. If the preset hot water start-up conditions are met, the system enters hot water operation control, allowing the hot water module to exchange heat with the refrigerant flowing through the dual-temperature-zone plate heat exchanger. If the preset conditions for heating and hot water operation are met, the system enters synchronous operation control, allowing the heating module and hot water module to exchange heat synchronously with the refrigerant flowing through the dual-temperature zone plate heat exchanger. If the preset conditions for heating shutdown are met, the system enters hot water operation control. If the preset conditions for hot water shutdown are met, the system enters heating operation control.

[0011] Furthermore, the heating start-up conditions include the current return water temperature T detected by the return water temperature sensor. w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set The difference; The heating shutdown conditions include the current return water temperature T. w,in Greater than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set sum.

[0012] Furthermore, the hot water activation condition includes the current hot water temperature T in the water tank detected by the hot water temperature sensor. w,tank The water temperature is less than the target T set in the water tank. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set The difference; The hot water shut-off condition includes the current hot water temperature T in the water tank. w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set sum.

[0013] Furthermore, the conditions for starting the heating + hot water operation include the current return water temperature T detected by the return water temperature sensor. w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in The difference, and the current hot water temperature T detected by the hot water temperature sensor in the water tank. w,tankThe water temperature is less than the target T set in the water tank. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set The difference; The conditions for complete shutdown include the current return water temperature T. w,in Greater than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set The sum of the values, and the current hot water temperature T in the water tank. w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set sum.

[0014] Furthermore, the control method is configured with an operational control strategy, including... Obtain the set return water temperature target T w,in,set and the target temperature T of the hot water tank w,tank,set , When performing heating operation control, the target return water temperature T is used. w,in,set To adjust the operating frequency of the variable frequency compressor in order to achieve the control target; When controlling the hot water operation, the target hot water temperature T in the water tank is used. w,tank,set To adjust the operating frequency of the variable frequency compressor in order to achieve the control target; When performing synchronous operation control, the larger value of the return water temperature target and the hot water tank temperature target is compared and used as the compressor control target to adjust the operating frequency of the variable frequency compressor. If the return water temperature target is greater than the hot water tank temperature target, the proportional three-way valve is adjusted to control the mixing water. If the return water temperature target is less than the hot water tank temperature target, the proportional three-way valve does not participate in the adjustment.

[0015] Furthermore, the synchronous operation control is configured with a three-way valve proportional adjustment strategy, including: When the target temperature of the hot water in the water tank is T w,tank,set greater than the target return water temperature T w,in,set hour, If T is satisfied w,in <T w,in,set -ΔT w,in,set At that time, the proportional three-way valve allows flow from port a to port b, but not from port a to port f. When T is satisfied w,in,set -ΔT w,in,set ≤T w,in <T w,in,set +ΔT w,in,set At that time, flow occurs from port a to port b of the proportional three-way valve, and flow also occurs from port a to port f. When T is satisfied w,in ≥T w,in,set +ΔT w,in,setWhen the heating reaches the set temperature, the heating stops and the proportional three-way valve switches to flow from port a to port b, and stops flow from port a to port f. When the return water temperature target T w,in,set Greater than the target temperature T of the hot water in the water tank w,tank,set hour, The proportional three-way valve allows flow from port a to port b, but not from port a to port f.

[0016] Furthermore, define the circulation ratio X. ab The flow rate X represents the ratio of hot water flowing through port b to hot water flowing through port a. af The three-way valve proportional adjustment strategy includes a flow ratio adjustment sub-strategy to determine the ratio of hot water flowing through port f to hot water flowing through port a. This sub-strategy is executed when the proportional three-way valve flows from port a to port b and from port a to port f. When the current return water temperature T w,in If it increases, then the circulation ratio X ab Reduce, circulation ratio X af Increase the size, and the circulation ratio X ab A lower threshold is set, when X... ab After being lowered to the lower threshold, the return water temperature T w,in If it continues to rise, then the circulation ratio X ab Maintain the lower threshold; When the current return water temperature T w,in If it decreases, then the circulation ratio X ab Increase the circulation ratio X af Turn it down.

[0017] The main technical effects of this invention are reflected in the following aspects: In this invention, a dual-temperature zone plate heat exchanger serves as the core component, achieving highly efficient heat exchange between the refrigerant and water. It supports the simultaneous production of domestic hot water and heating hot water, avoiding the downtime issues caused by mode switching in traditional systems. Furthermore, the proportional three-way valve solves the problem of excessively high heating return water temperature through mixing control, improving system energy efficiency. In particular, the multi-mode operation mechanism supports three operating modes: heating, hot water, and hot water + heating, flexibly meeting diverse user needs. In addition, the system achieves intelligent control through various sensors and control algorithms, ensuring stable and reliable system operation and improving energy utilization efficiency. Attached Figure Description

[0018] Figure 1 A schematic diagram of the overall structure of a novel combined heating and hot water supply system; Figure 2 A schematic diagram of the system flow path of a novel combined heating and hot water supply system in heating operation mode; Figure 3 A schematic diagram of the system flow path of a novel combined heating and hot water supply system in hot water mode; Figure 4 A schematic diagram of the system flow path of a novel combined heating and hot water system in heating + hot water operation mode; Figure 5 A schematic diagram of the control process of a new type of combined heating and hot water supply system.

[0019] Figure label: 1. Variable frequency compressor; 2. High pressure sensor; 3. Oil separator; 4. Four-way valve; 5. Dual-zone plate heat exchanger; 6. Electronic expansion valve; 7. Outdoor heat exchanger; 8. Gas-liquid separator; 9. Oil return capillary tube; 10. Heating water pump; 11. Proportional three-way valve; 12. Buffer tank; 13. Exhaust temperature sensor; 14. Ambient temperature sensor; 15. Coil temperature sensor; 16. Return gas temperature sensor; 17. Return water temperature sensor; 18. Outlet water temperature sensor; 21. Hot water tank; 22. Hot water pump; 23. Hot water temperature sensor. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so that the technical solution of the present invention can be more easily understood and mastered.

[0021] Example: A new type of combined heating and hot water supply system, please refer to... Figure 1 It includes a heat pump main unit module, a heating module and a hot water module; the heat pump main unit module includes a variable frequency compressor 1, an oil separator 3, a four-way valve 4, a dual-temperature zone plate heat exchanger 5, an electronic expansion valve 6, an outdoor heat exchanger 7 and a gas-liquid separator 8 connected in sequence, forming a refrigerant circulation main loop; The dual-temperature zone plate heat exchanger 5 is provided with a heating heat exchange channel and a hot water heat exchange channel. The heating heat exchange channel is connected to the heating module, and the hot water heat exchange channel is connected to the hot water module. The heating heat exchange channel and the hot water heat exchange channel are respectively supplied with hot water, so that the heating module and the hot water module can exchange heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger 5 independently or synchronously.

[0022] Furthermore, the heating module includes a hot water return pipe, a hot water outlet pipe, a proportional three-way valve 11, a heating water pump 10, and a buffer tank 12. The hot water return pipe and the hot water outlet pipe are respectively connected to the heating heat exchange channel. The heating water pump 10 is installed on the hot water return pipe. The proportional three-way valve 11 includes an a port, a b port, and an f port. The a port and b port of the proportional three-way valve 11 are connected to the hot water return pipe, and the f port of the proportional three-way valve 11 is connected to the hot water outlet pipe via the buffer tank 12. The proportional three-way valve 11 is used to adjust the proportion of hot water flowing through the heating heat exchange channel and the buffer tank 12.

[0023] Furthermore, the hot water module includes a hot water tank and a hot water pump. The hot water tank is connected to the hot water heat exchange channel through a hot water circulation pipeline to form a hot water circulation loop. The hot water pump drives the hot water to circulate between the hot water tank and the dual-temperature zone plate heat exchanger 5, so that the hot water exchanges heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger 5.

[0024] Furthermore, the exhaust pipe of the variable frequency compressor 1 is connected to the d pipe of the four-way valve 4 via the oil separator 3, the e pipe of the four-way valve 4 is connected to the inlet pipe of the dual-temperature zone plate heat exchanger 5 via the main gas pipe, the liquid outlet pipe of the dual-temperature zone plate heat exchanger 5 is connected to one end of the electronic expansion valve 6 via the main liquid pipe, the other end of the electronic expansion valve 6 is connected to one end of the outdoor heat exchanger 7, the other end of the outdoor heat exchanger 7 is connected to the c pipe of the four-way valve 4, the s pipe of the four-way valve 4 is connected to the inlet pipe of the gas-liquid separator 8, and the outlet pipe of the gas-liquid separator 8 is connected to the return gas pipe of the variable frequency compressor 1.

[0025] Furthermore, it also includes a temperature detection module, which comprises an exhaust temperature sensor, an ambient temperature sensor, a coil temperature sensor, a return gas temperature sensor, a return water temperature sensor, an outlet water temperature sensor, and a hot water temperature sensor 23. The exhaust temperature sensor is used to detect the exhaust temperature T. d The ambient temperature sensor is used to detect the ambient temperature T. ao The coil temperature sensor is used to detect the coil temperature T. def The return gas temperature sensor is used to detect the return gas temperature T. s The return water temperature sensor is used to detect the return water temperature T. w,in The outlet water temperature sensor is used to detect the outlet water temperature T of the hot water flowing out of the heating heat exchange channel. w,out The hot water temperature sensor 23 is used to detect the temperature T of the hot water in the hot water tank. w,tank .

[0026] The following section provides a further introduction based on the operating mode and the system's loop flow path: 1. Operating Mode 1.1 Heating Operation Mode When the unit receives the "heating" operation command, it starts the soft start operation mode. The heating water pump 10 starts, the hot water pump 22 stops, the variable frequency compressor 1 runs at a certain frequency, the fan of the outdoor heat exchanger 7 starts, and the electronic expansion valve 6 opens at a certain initial opening. After the soft start is completed, the variable frequency compressor 1 controls the operating frequency according to a certain return water temperature target, and the electronic expansion valve 6 adjusts the opening according to a certain return gas superheat target.

[0027] Heat pump heating circulation path combination Figure 2 The loop process is as follows: The refrigerant discharged from the variable frequency compressor 1 passes through the oil separator 3, the d-pipe of the four-way valve 4, and the e-pipe of the four-way valve 4 before entering the dual-temperature zone plate heat exchanger 5 for heat exchange. After heat exchange, the refrigerant passes through the electronic expansion valve 6, the outdoor heat exchanger 7, the c-pipe and the s-pipe of the four-way valve 4, and then returns to the variable frequency compressor 1 via the gas-liquid separator 8. The heating water pump 10 pumps hot water from the a-port of the proportional three-way valve 11 to the b-port. The proportional three-way valve 11 maintains X... ab =100% state, the hot water flowing out through interface b exchanges heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger 5 through the heating heat exchange channel. The hot water absorbs the heat released by the refrigerant, thus increasing the hot water temperature.

[0028] 1.2 Hot water operation mode When the unit receives the "hot water" operation command, it starts the soft start operation mode. The hot water pump 22 starts, the heating water pump 10 stops, the variable frequency compressor 1 runs at a certain frequency, the fan of the outdoor heat exchanger 7 starts, and the electronic expansion valve 6 opens at a certain initial opening. After the soft start is completed, the variable frequency compressor 1 controls the operating frequency according to a certain target hot water temperature in the water tank, and the electronic expansion valve 6 adjusts the opening according to a certain target return gas superheat.

[0029] Heat pump hot water heat circulation flow path combination Figure 3 The loop process is as follows: The refrigerant discharged from the variable frequency compressor 1 passes through the oil separator 3, the d-pipe of the four-way valve 4, and the e-pipe of the four-way valve 4 before entering the dual-temperature zone plate heat exchanger 5 for heat exchange. After heat exchange, the refrigerant passes through the electronic expansion valve 6, the outdoor heat exchanger 7, the c-pipe and the S-pipe of the four-way valve 4, and then returns to the variable frequency compressor 1 via the gas-liquid separator 8. The hot water pump 22 pumps hot water from the hot water tank 21 into the hot water heat exchange channel, where it exchanges heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger 5, absorbing the heat released by the refrigerant.

[0030] 1.3 Heating + Hot Water Operation Control Mode Upon receiving the "hot water + heating" operation command, the unit initiates a soft-start operation mode. Heating pump 10 and hot water pump 22 start, the variable frequency compressor 1 operates at a specific frequency, the outdoor heat exchanger 7's fan starts, and the electronic expansion valve 6 opens to a predetermined initial opening. After the soft-start operation concludes, the variable frequency compressor 1 adjusts its operating frequency according to the maximum set target hot water temperature in the tank and the set return water temperature. The electronic expansion valve 6 adjusts its opening according to a predetermined return gas superheat target. In this mode, when the target hot water temperature in the tank is greater than the set return water temperature, the flow ratio of the proportional three-way valve 11 is adjusted. When the target hot water temperature in the tank is less than or equal to the set return water temperature, the variable frequency compressor 1 adjusts its operating frequency according to the set return water temperature.

[0031] Combined hot water and heating system operation with heat circulation Figure 4 The loop process is as follows: The refrigerant discharged from the variable frequency compressor 1 passes through the oil separator 3, the d-pipe of the four-way valve 4, and the e-pipe of the four-way valve 4 before entering the dual-temperature zone plate heat exchanger 5 for heat exchange. After heat exchange, the refrigerant passes through the electronic expansion valve 6, the outdoor heat exchanger 7, the c-pipe and the s-pipe of the four-way valve 4, and then returns to the variable frequency compressor 1 via the gas-liquid separator 8.

[0032] When the target temperature of the hot water in the water tank is T w,tank,set greater than the target return water temperature T w,in,set At that time, the heating water pump 10 pumps hot water from port a to port b and port f of the proportional three-way valve 11. The proportional three-way valve 11 can adjust the proportion of hot water flowing out from port b and port f. The hot water flowing out from port b exchanges heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger 5 through the heating heat exchange channel. The hot water absorbs the heat released by the refrigerant and increases the hot water temperature. The hot water flowing out from port f merges with another hot water after passing through the buffer tank 12. When the return water temperature target T w,in,set Greater than the target temperature T of the hot water in the water tank w,tank,set At that time, the heating water pump 10 pumps hot water from port a to port b of the proportional three-way valve 11, and the proportional three-way valve 11 maintains X ab =100% state.

[0033] Hot water pump 22 pumps hot water from hot water tank 21 into hot water heat exchange channel, where it exchanges heat with the refrigerant flowing through dual-temperature plate heat exchanger 5 and absorbs the heat released by the refrigerant.

[0034] A novel control method for a combined heating and hot water supply system, the control method comprising: S1: Unit power-on initialization; S2: Configured with preset heating start conditions, hot water start conditions, and heating + hot water operation start conditions. If the heating start-up conditions are met, proceed to S3 for heating operation control; If the hot water activation conditions are met, proceed to step S4 to control the hot water operation. If the conditions for starting the heating and hot water operation are met, then proceed to S5 for synchronous operation control; S3: In heating mode, the target return water temperature T is set. w,in,set To control the target and adjust the operating frequency of the variable frequency compressor 1, a preset heating shutdown condition is configured. If the heating shutdown condition is met, the heating operation will stop. S4: In hot water mode, the target hot water temperature T in the water tank is set. w,tank,set To control the target and adjust the operating frequency of the variable frequency compressor 1, a preset hot water shut-off condition is configured. If the hot water shut-off condition is met, the hot water operation will stop. S5: In heating + hot water operation control mode, compare with the set return water temperature target T. w,in,set and the set target hot water temperature T in the water tank w,tank,set The variable frequency compressor 1 is adjusted by using a parameter with a larger value as the control target. It is configured with preset shutdown conditions, hot water shutdown conditions and heating shutdown conditions. If the shutdown condition is met, the heating module and the hot water module will both shut down. If the hot water shutdown condition is met, the hot water operation will stop and the process will enter S3 for heating operation control. If the heating shutdown condition is met, the heating operation will stop and the process will enter S4 for hot water operation control.

[0035] Furthermore, the heating start-up conditions include the current return water temperature T detected by the return water temperature sensor 17. w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set The difference; The heating shutdown conditions include the current return water temperature T. w,in Greater than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set sum.

[0036] Furthermore, the hot water activation condition includes the current hot water temperature T detected by the hot water temperature sensor 23 in the water tank. w,tank The water temperature is less than the target T set in the water tank. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set The difference; The hot water shut-off condition includes the current hot water temperature T in the water tank. w,tankThe target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set sum.

[0037] Furthermore, the conditions for starting the heating + hot water operation include the current return water temperature T detected by the return water temperature sensor 17. w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in The difference, and the current hot water temperature T detected by the hot water temperature sensor 23 in the water tank. w,tank The water temperature is less than the target T set in the water tank. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set The difference; The conditions for complete shutdown include the current return water temperature T. w,in Greater than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set The sum of the values, and the current hot water temperature T in the water tank. w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set sum.

[0038] Furthermore, in step S5, when the target temperature T of the hot water in the water tank... w,tank,set greater than the target return water temperature T w,in,set At that time, a three-way valve proportional regulation strategy is configured, defining the flow ratio X. ab The flow rate X represents the ratio of hot water flowing through port b to hot water flowing through port a. af The three-way valve proportional adjustment strategy includes the following: (1) To determine the ratio of hot water flowing through port f to hot water flowing through port a. If T is satisfied w,in <T w,in,set -ΔT w,in,set At that time, the proportional three-way valve flows from a to b, with a flow ratio of X. ab =100%, no flow from a to f, flow ratio X af =0; When T is satisfied w,in,set -ΔT w,in,set ≤T w,in <T w,in,set +ΔT w,in,set At that time, the proportional three-way valve distributes the flow according to a certain ratio, with flow from a to b and from a to f: when the current return water temperature T w,in If it increases, then the circulation ratio X ab Reduce, circulation ratio X af Increase the size, and the circulation ratio X abA lower threshold is set, when X... ab After being lowered to the lower threshold, the return water temperature T w,in If it continues to rise, then the circulation ratio X ab Maintain the lower threshold; when the current return water temperature T w,in If it decreases, then the circulation ratio X ab Increase the circulation ratio X af Turn it down; When T is satisfied w,in ≥T w,in,set +ΔT w,in,set When the heating reaches the set temperature, the heating system stops operating, and the proportional three-way valve switches to X. ab =100% state and maintain it.

[0039] In step S5, when the return water temperature reaches the target T w,in,set Greater than the target temperature T of the hot water in the water tank w,tank,set At that time, the proportional three-way valve 11a flows to b, with a flow ratio of X. ab =100%, no flow from a to f, flow ratio X af =0.

[0040] The following section provides further details on specific operating modes: 2. Control of various operating modes 2.1 Heating Operation Control 2.1.1 Activation Conditions Upon receiving the "heating" operation command, the heating water pump 10 starts running. Simultaneously, the return water temperature sensor 17 and the outlet water temperature sensor 18 detect the return water temperature T. w,in and outlet water temperature T w,out The unit will start providing heating if all of the following heating start conditions are met.

[0041] 1) The current return water temperature T detected by return water temperature sensor 17 w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT with return water temperature w,in,set The difference, i.e.: T w,in <T w,in,set -ΔT w,in,set hysteresis ΔT w,in Generally, 1-2℃ is used; 2) The flow switch detected that the water flow rate was normal; 3) No fault was detected in the unit, and the shutdown lasted for more than 3 minutes.

[0042] 2.1.2 Operation Control When all the above heating start-up conditions are met, the unit starts running, the compressor starts, the fan on the outdoor heat exchanger 7 starts running, the hot water pump 22 stops, and the electronic expansion valve 6 adjusts its opening according to a certain superheat, as follows: The variable frequency compressor 1 first performs soft start control. After starting and running at the reference frequency Fr0, the variable frequency compressor 1 runs at this frequency for a soft start time t0, and then runs at the set return water temperature target T. w,in,set The frequency is adjusted to control the target.

[0043] When the current return water temperature T w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT with return water temperature w,in,set When the difference is T w,in <T w,in,set -ΔT w,in,set The variable frequency compressor 1 operates at a certain frequency ramp rate Fr up Adjustments are made at regular intervals t. ad Adjust once.

[0044] When the current return water temperature T w,in Greater than or equal to the set target return water temperature T w,in,set Hysteresis ΔT with return water temperature w,in,set The difference, but less than or equal to the set target return water temperature T. w,in,set When, i.e., T w,in,set -ΔT w,in,set ≤T w,in ≤T w,in,set The variable frequency compressor 1 maintains its current operating frequency.

[0045] When the current return water temperature T w,in Greater than the set return water temperature target T w,in,set However, it is less than or equal to the set target return water temperature T. w,in,set Hysteresis ΔT with return water temperature w,in,set When the sum is T, that is, when T is T w,in,set <T w,in ≤T w,in,set +ΔT w,in At that time, the compressor operates at a certain frequency reduction rate Fr down Adjustments are made at regular intervals t. ad Adjust once.

[0046] When the current return water temperature T w,in Greater than the set return water temperature target T w,in,set Add the return water temperature hysteresis ΔT w,in,set (Generally taken as 1-2℃), that is: T w,in >T w,in,set +ΔTw,in,set This indicates that the unit has reached the set control target, the unit stops running, the variable frequency compressor 1 stops, the fan of the outdoor heat exchanger 7 stops running, and the heating water pump 10 runs for a period of time. on-off Then stop.

[0047] During the soft start phase, the main unit's electronic expansion valve 6 opens to a certain initial degree, set to V0. After the soft start operation is completed, the intake superheat target value ΔT is reached. s,set To adjust its opening degree, superheat ΔT s Defined as the inhalation temperature T detected by the inhalation temperature sensor s Subtract the temperature T detected by the coil temperature sensor 15 of the outdoor heat exchanger 7. def .

[0048] 2.2 Hot water operation control 2.2.1 Activation Conditions When the unit receives the "hot water" operation command, hot water pump 22 starts running, heating water pump 10 stops running, and at the same time, hot water temperature sensor 23 detects the hot water temperature T. w,tank The unit will start producing hot water if all of the following hot water start conditions are met.

[0049] 1) The current hot water temperature T detected by hot water temperature sensor 23 in the water tank w,tank The water temperature is less than the target T set in the water tank. w,tank,set Subtract the hysteresis ΔT of the hot water temperature w,tank,set (Generally taken as 1-2℃), that is: T w,tank <T w,tank,set -ΔT w,tank,set ; 2) The flow switch detected that the water flow rate was normal; 3) No fault was detected in the unit, and the shutdown lasted for more than 3 minutes.

[0050] 2.2.2 Operation Control When the unit starts up, the variable frequency compressor 1 starts, the fan on the outdoor heat exchanger 7 starts running, the heating water pump 10 stops, and the electronic expansion valve 6 adjusts its opening according to a certain superheat. The specific control is as follows: The variable frequency compressor 1 first performs soft start control, and after starting and running at the reference frequency Fr0, it runs at this frequency for a soft start time t0, and then runs at the set target hot water temperature T in the water tank. w,tank,set The frequency is adjusted to control the target.

[0051] When the current hot water temperature in the water tank is T w,tank The water temperature is less than the target T set in the water tank. w,in,set Hysteresis ΔT with hot water temperature w,tank,set When the difference is Tw,tank <T w,tank,set -ΔT w,tank,set The variable frequency compressor 1 adjusts according to a certain frequency increase rate, and at regular intervals t... ad Adjust once.

[0052] When the current hot water temperature in the water tank is T w,tank Greater than or equal to the set target hot water temperature T in the water tank w,tank,set Hysteresis ΔT with the set hot water temperature w,tank,set The difference, but less than or equal to the set target hot water temperature T in the water tank. w,tank,set When, i.e., T w,tank,set -ΔT w,tank,set ≤T w,tank ≤T w,tank,set The variable frequency compressor 1 maintains its current operating frequency.

[0053] When the current hot water temperature in the water tank is T w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set However, it is less than or equal to the set target hot water temperature T in the water tank. w,tank,set Hysteresis ΔT with hot water temperature w,tank,set When the sum is T, that is, when T is T w,tank,set <T w,tank ≤T w,tank,set +ΔT w,tank,set At that time, the variable frequency compressor 1 adjusts according to a certain frequency reduction rate, and at certain intervals t... ad Adjust once.

[0054] When the current hot water temperature in the water tank is T w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Add the hysteresis ΔT of hot water temperature w,tank.set (Generally taken as 1-2℃), that is: T w,tank >T w,tank,set +ΔT w,tank,set This indicates that the unit has reached the set control target, the unit stops running, the variable frequency compressor 1 stops, the fan on the outdoor heat exchanger 7 stops running, and the hot water pump 22 runs for a period of time. on-off Then stop.

[0055] During the soft start phase, the main unit's electronic expansion valve 6 opens to a certain initial degree, set to V0. After the soft start operation is completed, the intake superheat target value ΔT is reached. s,set To adjust its opening degree, superheat ΔT s Defined as the inhalation temperature T detected by the inhalation temperature sensor s Subtract the temperature T detected by the coil temperature sensor of the outdoor heat exchanger. def .

[0056] 2.3 Hot water + heating operation control 2.3.1 Activation Conditions Upon receiving the "heating + hot water" operation command, the heating water pump 10 and the hot water pump 22 start operation. Simultaneously, the return water temperature sensor 17 and the outlet water temperature sensor 18 detect the return water temperature and outlet water temperature, respectively, while the hot water temperature sensor 23 detects the hot water temperature T. w,tank If all of the following conditions for heating and hot water operation are met, the unit will start producing hot water and providing heating.

[0057] 1) The current return water temperature T detected by return water temperature sensor 17 w,in Less than the set return water temperature target T w,in,set Subtract the hysteresis ΔT of the return water temperature w,in That is: T w,in <T w,in,set -ΔT w,in .

[0058] 2) The current hot water temperature T detected by hot water temperature sensor 23 in the water tank w,tank The water temperature is less than the target T set in the water tank. w,tank,set Subtract the hysteresis ΔT of the hot water temperature w,tank,set That is: T w,tank <T w,tank,set -ΔT w,tank,set .

[0059] 3) The flow switch detected that the water flow rate was normal; 4) No fault was detected in the unit, and the shutdown lasted for more than 3 minutes.

[0060] If all the above conditions for starting heating and hot water operation are met, the unit will start operating in "heating and hot water" mode.

[0061] If the above conditions cannot be met simultaneously, the "hot water" start-up condition and the "heating" start-up condition will be determined separately. If the start-up conditions of each of the above operating modes are met, the corresponding operating modes will be controlled.

[0062] 2.3.2 Operation Control When the above heating and hot water operation conditions are met simultaneously, the unit starts running, the variable frequency compressor 1 starts, the fan on the outdoor heat exchanger 7 starts running, the heating water pump 10 starts running, the hot water pump 22 starts running, and the main unit's electronic expansion valve 6 opens to a certain initial degree.

[0063] 1) Operation control of variable frequency compressor 1 If the conditions for starting heating and hot water operation are met, compare the set water temperature T of the hot water operation mode. w,tank,set Heating operation mode setting and return water set temperature T w,in,setTake the larger target value max{T} w,tank,set ,T w,in,set} As the control target, control the operating frequency of variable frequency compressor 1.

[0064] The variable frequency compressor 1 first performs soft start control, and after starting and running at the reference frequency Fr0, it runs at this frequency for a soft start time t0, and then at max{T}... w,tank,set ,T w,in,set} Adjust the frequency to control the target.

[0065] First scenario: Hot water temperature T in hot water operation mode w,tank,set The return water temperature T is greater than the target temperature of the heating operation mode. w,in,set The control of variable frequency compressor 1 is as follows: The variable frequency compressor 1 first performs soft start control, and after starting and running at the reference frequency Fr0, it runs at this frequency for a soft start time t0, and then runs at the set target hot water temperature T in the water tank. w,tank,set The frequency is adjusted to control the target.

[0066] When the current hot water temperature in the water tank is T w,tank The water temperature is less than the target T set in the water tank. w,tank,set Hysteresis ΔT with hot water temperature w,tank,set When the difference is T, that is: w,tank <T w,tank,set -ΔT w,tank.set The variable frequency compressor 1 adjusts according to a certain frequency ramp-up rate, and at regular intervals t... ad Adjust once.

[0067] When the current hot water temperature in the water tank is T w,tank Greater than or equal to the set target hot water temperature T in the water tank w,tank,set Hysteresis ΔT with the set hot water temperature w,tank,set The difference, but less than or equal to the set target hot water temperature T in the water tank. w,tank,set When, i.e., T w,tank,set -ΔT w,tank,set ≤T w,tank ≤T w,tank,set The variable frequency compressor 1 maintains its current operating frequency.

[0068] When the current hot water temperature in the water tank is T w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set However, it is less than or equal to the set target hot water temperature T in the water tank. w,tank,set Hysteresis ΔT with hot water temperature w,tank,set When the sum is T, that is, when T is T w,tank,set <T w,tank ≤T w,tank,set+ΔT w,tank,set At that time, the variable frequency compressor 1 adjusts according to a certain frequency reduction rate, and at certain intervals t... ad Adjust once.

[0069] When the current hot water temperature in the water tank is T w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Add the hysteresis ΔT of hot water temperature w,tank,set (Generally taken as 1-2℃), that is: T w,tank >T w,tank,set +ΔT w,tank,set This indicates that the unit has reached the set control target, the hot water heating has stopped, and the hot water pump 22 has been running for a period of time. on-off Then stop.

[0070] Next, the heating operation mode is determined. If the heating shutdown conditions are not met, the heating operation mode is maintained, and the control method follows the heating operation mode control. If both operation modes meet the shutdown conditions, the unit stops operating.

[0071] When both modes are running simultaneously, for heating operation mode: A, target return water temperature T w,in,set Higher than the target temperature T of the hot water in the water tank w,tank,set At that time, the frequency of variable frequency compressor 1 is set according to the target return water temperature T. w,in,set To adjust, there is no need to adjust the proportional three-way valve 11, and at this time, the flow from a to b in the proportional three-way valve is proportional to X. ab =100%, no flow from a to f, flow ratio X af =0, otherwise, adjusting both the frequency of the variable frequency compressor 1 and the proportional three-way valve 11 will make it difficult for the system to operate stably. B. Target hot water temperature T in the water tank w,tank,set Higher than the target return water temperature T w,in,set At that time, because the variable frequency compressor 1 operates at a frequency according to the set target hot water temperature T in the water tank. w,tank,set To ensure stable water temperature on the heating side, reduce the number of times the heating side reaches the desired temperature, and avoid frequent system start-ups and shutdowns, a proportional three-way valve 11 is used for mixing control. The proportional three-way valve 11 participates in mixing control, regulating the flow rate of return water into the dual-temperature zone plate heat exchanger 5. The specific control is as follows: If T w,in <T w,in,set -ΔT w,in,set At that time, the proportional three-way valve flows from a to b, with a flow ratio of X. ab =100%, no flow from a to f, flow ratio X af =0; When T is satisfied w,in,set -ΔT w,in,set ≤T w,in <Tw,in,set +ΔT w,in,set At that time, the proportional three-way valve distributes the flow according to a certain ratio, with flow from a to b and from a to f: when the current return water temperature T w,in If it increases, then the circulation ratio X ab Reduce, circulation ratio X af Increase the size, and the circulation ratio X ab A lower threshold is set, when X... ab After being lowered to the lower threshold, the return water temperature T w,in If it continues to rise, then the circulation ratio X ab Maintain the lower threshold; when the current return water temperature T w,in If it decreases, then the circulation ratio X ab Increase the circulation ratio X af Turn it down; When T is satisfied w,in >T w,in,set +ΔT w,in,set When the heating reaches the set temperature, the heating system stops operating, and the proportional three-way valve switches to X. ab =100% state and maintain it.

[0072] The second scenario: Target return water temperature T for heating operation mode w,in,set The target hot water temperature T in the water tank is greater than the hot water operation mode. w,tank,set The variable frequency compressor 1 is controlled as follows: The variable frequency compressor 1 first performs soft start control, and after starting and running at the reference frequency Fr0, it runs at this frequency for a soft start time t0, and then runs at the set return water temperature target T. w,in,set The frequency is adjusted to control the target.

[0073] When the current return water temperature T w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT with return water temperature w,in,set When the difference is T w,in <T w,in,set -ΔT w,in,set The compressor adjusts its frequency according to a certain rate of increase, and at regular intervals t... ad Adjust once.

[0074] When the current return water temperature T w,in Greater than or equal to the set target return water temperature T w,in,set Hysteresis ΔT with return water temperature w,in,set The difference, but less than or equal to the set target return water temperature T. w,in,set When, i.e., T w,in,set -ΔT w,in,set ≤T w,in ≤Tw,in,set The variable frequency compressor 1 maintains its current operating frequency.

[0075] When the current return water temperature T w,in Greater than the set return water temperature target T w,in,set However, it is less than or equal to the set target return water temperature T. w,in,set Hysteresis ΔT with return water temperature w,in,set When the sum is T, that is, when T is T w,in,set <T w,in ≤T w,in,set +ΔT w,in At that time, the compressor operates at a certain frequency reduction rate Fr down Adjustments are made at regular intervals t. ad Adjust once.

[0076] When the current return water temperature T w,in Greater than the set return water temperature target T w,in,set Add the return water temperature hysteresis ΔT w,in,set (Generally taken as 1-2℃), that is: T w,in >T w,in,set +ΔT w,in,set This indicates that the unit has reached the set control target, heating operation has stopped, and heating water pump 10 has been running for a period of time. on-off Then stop.

[0077] In this case, the proportional three-way valve 11 does not participate in the regulation, and the flow ratio X is [not specified]. ab =100%.

[0078] The system determines the hot water operation mode. If the shutdown conditions are not met, the hot water operation mode is maintained, and the control method follows the hot water operation mode control. If both operation modes simultaneously meet the shutdown conditions, the unit stops operating.

[0079] 2) Control of electronic expansion valve 6 During the soft start phase, the electronic expansion valve 6 opens to a certain initial degree, set to V0. After the soft start operation is completed, it operates according to a certain target value of suction superheat ΔT. s,set To adjust its opening degree, superheat ΔT s Defined as the inhalation temperature T detected by the inhalation temperature sensor s Subtract the temperature T detected by the coil temperature sensor of the outdoor heat exchanger. def .

[0080] 2.4 Added Operating Mode When the heating operation mode is activated, the "hot water" function is turned on. The control method is the same as that in 2.3. The larger value between the target hot water temperature in the water tank and the target return water temperature in the two operation modes is used as the control target for the operating frequency of the variable frequency compressor 1.

[0081] Similarly, when the hot water operation mode is activated, the "heating" function is turned on, and the control method is the same as that in 2.3. The larger value of the target hot water temperature in the water tank and the target return water temperature in the two operation modes is used as the control target for the operating frequency of the variable frequency compressor 1.

[0082] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A novel combined heating and hot water supply system, characterized in that: It includes a heat pump main unit module, a heating module and a hot water module; the heat pump main unit module includes a variable frequency compressor (1), an oil separator (3), a four-way valve (4), a dual-temperature zone plate heat exchanger (5), an electronic expansion valve (6), an outdoor heat exchanger (7) and a gas-liquid separator (8) connected in sequence, forming a refrigerant circulation main loop; The dual-temperature zone plate heat exchanger (5) is provided with a heating heat exchange channel and a hot water heat exchange channel. The heating heat exchange channel is connected to the heating module, and the hot water heat exchange channel is connected to the hot water module. The heating heat exchange channel and the hot water heat exchange channel are respectively supplied with hot water, so that the heating module and the hot water module can exchange heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger (5) independently or synchronously.

2. The novel combined heating and hot water supply system according to claim 1, characterized in that: The heating module includes a hot water return pipe, a hot water outlet pipe, a proportional three-way valve (11), a heating water pump (10), and a buffer tank (12). The hot water return pipe and the hot water outlet pipe are respectively connected to the heating heat exchange channel. The heating water pump (10) is installed on the hot water return pipe. The proportional three-way valve (11) includes an a port, a b port, and an f port. The a port and b port of the proportional three-way valve (11) are connected to the hot water return pipe. The f port of the proportional three-way valve (11) is connected to the hot water outlet pipe via the buffer tank (12). The proportional three-way valve (11) adjusts the proportion of hot water flowing through the heating heat exchange channel and the buffer tank (12) by adjusting the proportion of hot water flowing from the a port to the b port and the f port.

3. The novel combined heating and hot water supply system according to claim 1, characterized in that: The hot water module includes a hot water tank (21) and a hot water pump (22). The hot water tank is connected to the hot water heat exchange channel through a hot water circulation pipeline to form a hot water circulation loop. The hot water pump drives the hot water to circulate between the hot water tank and the dual-temperature plate heat exchanger (5), so that the hot water exchanges heat with the refrigerant flowing through the dual-temperature plate heat exchanger (5).

4. The novel combined heating and hot water supply system according to claim 1, characterized in that: The exhaust pipe of the variable frequency compressor (1) is connected to the d pipe of the four-way valve (4) via the oil separator (3). The e pipe of the four-way valve (4) is connected to the inlet pipe of the dual-temperature zone plate heat exchanger (5) via the main gas pipe. The liquid outlet pipe of the dual-temperature zone plate heat exchanger (5) is connected to one end of the electronic expansion valve (6) via the main liquid pipe. The other end of the electronic expansion valve (6) is connected to one end of the outdoor heat exchanger (7). The other end of the outdoor heat exchanger (7) is connected to the c pipe of the four-way valve (4). The s pipe of the four-way valve (4) is connected to the inlet pipe of the gas-liquid separator (8). The outlet pipe of the gas-liquid separator (8) is connected to the return pipe of the variable frequency compressor (1).

5. The novel combined heating and hot water supply system according to claim 3, characterized in that: It also includes a temperature detection module, which comprises an exhaust temperature sensor (13), an ambient temperature sensor (14), a coil temperature sensor (15), a return air temperature sensor (16), a return water temperature sensor (17), an outlet water temperature sensor (18), and a hot water temperature sensor (23). The exhaust temperature sensor (13) is used to detect the exhaust temperature T. d The ambient temperature sensor (14) is used to detect the ambient temperature T. ao The coil temperature sensor (15) is used to detect the coil temperature T. def The return gas temperature sensor (16) is used to detect the return gas temperature T. s The return water temperature sensor (17) is used to detect the return water temperature T. w,in The outlet water temperature sensor (18) is used to detect the outlet water temperature T of the hot water flowing out of the heating heat exchange channel. w,out The hot water temperature sensor (23) is used to detect the temperature T of the hot water in the hot water tank. w,tank .

6. A novel control method for a combined heating and hot water supply system, applied to the novel combined heating and hot water supply system as described in any one of claims 1-5, characterized in that: The control method is configured with heating start-up conditions, hot water start-up conditions, and heating + hot water operation start-up conditions. If the preset heating start-up conditions are met, the heating operation control will be activated, allowing the heating module to exchange heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger (5). If the preset hot water start-up conditions are met, the hot water operation control is activated, allowing the hot water module to exchange heat with the refrigerant flowing through the dual-temperature zone plate heat exchanger (5). If the preset heating + hot water operation start conditions are met, synchronous operation control is entered, so that the heating module and hot water module exchange heat synchronously with the refrigerant flowing through the dual-temperature zone plate heat exchanger (5). If the preset heating shutdown adjustment is met, hot water operation control is entered. If the preset hot water shutdown conditions are met, heating operation control is entered.

7. The control method for the novel combined heating and hot water supply system according to claim 6, characterized in that, The control method is configured with an operational control strategy, including: Obtain the set return water temperature target T w,in,set and the target temperature T of the hot water tank w,tank,set , When performing heating operation control, the target return water temperature T is used. w,in,set To adjust the operating frequency of the variable frequency compressor (1) in order to achieve the control target; When controlling the hot water operation, the target hot water temperature T in the water tank is used. w,tank,set To adjust the operating frequency of the variable frequency compressor (1) in order to achieve the control target; When performing synchronous operation control, the larger value of the return water temperature target and the hot water tank temperature target is compared and used as the compressor control target to adjust the operating frequency of the variable frequency compressor (1). If the return water temperature target is greater than the hot water tank temperature target, the proportional three-way valve is adjusted to perform water mixing control. If the return water temperature target is less than the hot water tank temperature target, the proportional three-way valve does not participate in the adjustment.

8. The control method for the novel combined heating and hot water supply system according to claim 7, characterized in that, The synchronous operation control is configured with a three-way valve proportional adjustment strategy, including: When the target temperature of the hot water in the water tank is T w,tank,set greater than the target return water temperature T w,in,set hour, If T is satisfied w,in <T w,in,set -ΔT w,in,set At that time, the proportional three-way valve (11) allows flow from port a to port b, but not from port a to port f. When T is satisfied w,in,set -ΔT w,in,set ≤T w,in <T w,in,set +ΔT w,in,set At that time, the proportional three-way valve (11) flows from port a to port b, and from port a to port f. When T is satisfied w,in ≥T w,in,set +ΔT w,in,set When the heating reaches the set temperature, the heating stops and the proportional three-way valve switches to flow from port a to port b, and stops flow from port a to port f. When the return water temperature target T w,in,set Greater than the target temperature T of the hot water in the water tank w,tank,set hour, The proportional three-way valve (11) allows flow from port a to port b, but not from port a to port f.

9. The control method for the novel combined heating and hot water supply system according to claim 8, characterized in that: Define the circulation ratio X ab The flow rate X represents the ratio of hot water flowing through port b to hot water flowing through port a. af The ratio of hot water flowing through port f to hot water flowing through port a is defined by the three-way valve proportional adjustment strategy, which includes a flow ratio adjustment sub-strategy. This sub-strategy is executed when the proportional three-way valve (11) flows from port a to port b and from port a to port f. When the current return water temperature T w,in If it increases, then the circulation ratio X ab Reduce, circulation ratio X af Increase the size, and the circulation ratio X ab A lower threshold is set, when X... ab After being lowered to the lower threshold, the return water temperature T w,in If it continues to rise, then the circulation ratio X ab Maintain the lower threshold; When the current return water temperature T w,in If it decreases, then the circulation ratio X ab Increase the circulation ratio X af Turn it down.

10. The control method for the novel combined heating and hot water supply system according to claim 6, characterized in that: The heating start-up conditions include the current return water temperature T detected by the return water temperature sensor (17). w,in Less than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set The difference; The heating shutdown conditions include the current return water temperature T. w,in Greater than the set return water temperature target T w,in,set Hysteresis ΔT from the preset return water temperature w,in,set sum; The hot water activation condition includes the current hot water temperature T detected by the hot water temperature sensor (23) in the water tank. w,tank The water temperature is less than the target T set in the water tank. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set The difference; The hot water shut-off condition includes the current hot water temperature T in the water tank. w,tank The target hot water temperature T in the water tank is greater than the set temperature. w,tank,set Hysteresis ΔT from the preset hot water temperature w,tank,set sum; When both the heating start-up condition and the hot water start-up condition are met simultaneously, it is considered that the heating + hot water operation start-up condition is met.

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