Hot water constant-pressure water supply system based on solar energy

Abstract

The invention discloses a hot water constant-pressure water supply system based on solar energy, which comprises a water tank water replenishing system, a heating circulation system, a constant-pressure water supply system and a control system, the water tank water replenishing system comprises a water replenishing electric valve, a preheating water tank, a hot water transition pump, a water supply tank and a liquid level transmitter; the heating circulation system comprises a solar heat collector, a temperature transmitter, an exhaust valve, a circulation pump set, an air energy heat source pump set, an air energy heat source pump circulation pump, a heater circulation pump, a rapid water heater, a hot water frequency conversion pressure pump and a pressure transmitter. The control system comprises a PLC (Programmable Logic Controller), a touch screen, an analog quantity module, a circuit breaker, an alternating current contactor, an intermediate relay and a thermal relay; a triple heating mode of the solar heat collector, the air energy heat source pump and the rapid water heater is adopted, limitation of weather conditions is avoided, it is ensured that hot water is stably supplied under various weather conditions, solar energy is preferentially used, the air energy heat source pump is used in an auxiliary mode, and energy consumption is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of secondary water supply, in particular to a hot water constant pressure water supply system based on solar energy. BACKGROUND

[0002] At present, the water temperature of the user end of the secondary water supply system on the market is normal temperature, and if the user needs to use hot water, a water heater and an electric heater need to be installed independently.

[0003] This hot water supply mode has defects: Firstly, the cost is high, and the user needs to additionally invest in equipment purchase and installation costs; Secondly, the work efficiency is low, and the decentralized heating cannot realize large-scale supply, which cannot meet the centralized hot water demand of schools, hotels and commercial buildings; Thirdly, the resource waste is serious, the energy utilization rate of independent heating equipment is low, and there is a lack of unified energy-saving control mechanism.

[0004] In order to solve the above problems, it is necessary to design a hot water constant pressure water supply system with integration, automation and energy saving. SUMMARY

[0005] The present application provides a hot water constant pressure water supply system based on solar energy, which can stably supply hot water, keep the water temperature constant and reduce resource waste.

[0006] In order to achieve the above purpose, the technical scheme of the present application is: A hot water constant pressure water supply system based on solar energy, comprising a water tank water replenishing system, a heating circulation system, a constant pressure water supply system and a control system, The water tank water replenishing system comprises a water replenishing electric valve, a preheating water tank temperature transmitter, a preheating water tank, a hot water transition pump, a preheating water tank liquid level transmitter, a water supply tank and a hot water tank liquid level transmitter, the water replenishing electric valve is arranged on the water inlet pipeline of the preheating water tank, the preheating water tank liquid level transmitter is arranged in the preheating water tank, and the hot water tank liquid level transmitter is arranged in the water supply tank, The heating circulation system includes a solar collector, a collector temperature transmitter, an exhaust valve, a circulation pump set, an air source heat pump unit, an air source heat pump circulation pump, a first hot water tank temperature transmitter, a heater circulation pump, a second hot water tank temperature transmitter, a rapid water heater, a hot water frequency conversion pressurization pump, and a pressure transmitter. The solar collector is connected to the preheating water tank via pipelines. The collector temperature transmitter is located at the beginning of the pipeline from the solar collector to the preheating water tank, and the preheating water tank temperature transmitter is located at the beginning of the pipeline from the preheating water tank to the solar collector. The circulation pump set is located on the pipeline between the preheating water tank output and the solar collector input. The air source heat pump unit is connected to the preheating water tank and the supply water tank via pipelines. A hot water transition pump is installed in the pipeline between the output end of the preheating water tank and the input end of the air source heat pump unit. The air source heat pump circulation pump is installed in the pipeline between the output end of the water supply tank and the input end of the air source heat pump unit. The first water supply tank temperature transmitter is installed at the beginning of the pipeline from the water supply tank to the air source heat pump unit. The output end of the rapid water heater is connected to the input end of the water supply tank through a pipeline. The heater circulation pump is installed in the pipeline between the output end of the water supply tank and the input end of the rapid water heater. The second water supply tank temperature transmitter is installed at the beginning of the pipeline from the water supply tank to the rapid water heater. The hot water variable frequency booster pump is located on the outlet pipeline of the water supply tank. The pressure transmitter is installed on the pipeline at the output end of the hot water variable frequency booster pump. The control system includes a PLC controller, a touch screen, analog modules, circuit breakers, AC contactors, intermediate relays, and thermal relays. The programmable controller is electrically connected to the touch screen, analog modules, AC contactors, and intermediate relays. The analog modules are electrically connected to each temperature transmitter, level transmitter, and pressure transmitter. The AC contactors are electrically connected to each pump. The circuit breakers are used to control the on / off state of the power circuits of each device. The thermal relays are used for overload protection of the pump motor.

[0007] Furthermore, two units are respectively installed for the circulating pump group, hot water transition pump, air source heat pump circulating pump, heater circulating pump and hot water variable frequency booster pump, which operate alternately.

[0008] Furthermore, the water replenishment electric valve is internally equipped with an over-torque limit, a valve opening limit, a closing torque limit, and a valve closing limit.

[0009] Furthermore, the PLC controller communicates with the frequency converter of the hot water variable frequency booster pump via MODBUS-RTU to collect motor frequency, operating voltage, and operating current parameters in real time, which are then displayed on a touch screen.

[0010] Furthermore, the PLC controller performs PID calculations based on the 4~20mA analog signal collected by the pressure transmitter and the set pressure value, and outputs a 0~10V signal to control the frequency converter frequency to adjust the water pump speed.

[0011] Furthermore, the control system is equipped with a manual / automatic switch. When the manual / automatic switch is in manual mode, the start and stop of each pump group and valve are controlled by a rotary switch.

[0012] Furthermore, the control system is equipped with a flashing buzzer, which activates an audible and visual alarm when a water pump malfunction, water shortage malfunction, overpressure malfunction, or pipe burst malfunction is detected.

[0013] Furthermore, an ultraviolet sterilizer is installed at the beginning of the water outlet pipe of the water supply tank.

[0014] Compared with the prior art, the present invention has the following advantages: It adopts a triple heating mode of solar collector, air source heat pump and rapid water heater, which is not limited by weather conditions and ensures a stable supply of hot water in sunny, rainy or snowy weather, and the water temperature remains constant.

[0015] Solar energy is prioritized, supplemented by air source heat pumps, and rapid water heaters are activated in special circumstances, effectively reducing energy consumption from traditional electric or gas heating and minimizing resource waste.

[0016] It adopts a full variable frequency constant pressure water supply mode and adjusts the water pump speed in real time through PID regulation algorithm to keep the water supply pressure within the set range. This avoids the problem of unstable water flow caused by pressure fluctuations and can meet the centralized hot water supply needs of various places such as schools, hotels, office buildings, and residential communities. Users do not need to install heating equipment separately. Attached Figure Description

[0017] Figure 1 This is a partial structural diagram of the present invention; Figure 2 This is another partial structural diagram of the present invention; Figure 3 This is a schematic diagram of the circulating pump set, hot water transfer pump, and air source heat pump circulating pump of the present invention; Figure 4 This is a schematic diagram of the hot water variable frequency booster pump of the present invention; Figure 5 This is the control circuit diagram of the pump of the present invention; Figure 6 This is a control loop diagram of the valve and transmitter of the present invention; Figure 7 This is the control loop diagram of the PLC of the present invention; Figure 8This is a schematic diagram of the analog quantity module of the present invention; Figure 9 This is a flowchart illustrating the automatic water replenishment process of the present invention. Figure 10 This is a flowchart illustrating the solar-powered circulating heating process of the present invention. Figure 11 This is a flowchart illustrating the water replenishment process of the present invention. Figure 12 This is a flowchart illustrating the water supply tank heating process of the present invention. Figure Labels

[0018] 1. Solar collector, 2. Collector temperature transmitter, 3. Exhaust valve 4. Circulating pump set; 5. Electric water supply valve; 6. Temperature transmitter for preheated water tank. 7. Preheating water tank; 8. Hot water transfer pump; 9. Preheating water tank level transmitter. 10. Control system, 11. Air source heat pump unit, 12. Water supply tank. 13. Hot water tank level transmitter; 14. Air source heat pump circulation pump. 15. Temperature transmitter for the first hot water supply tank; 16. Heater circulation pump. 17. Temperature transmitter for the second hot water supply tank; 18. Rapid-action water heater. 19 Hot water variable frequency booster pump, 20 Pressure transmitter, 21 Ultraviolet sterilizer. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This embodiment proposes a solar-based constant-pressure hot water supply system, such as... Figure 1 and Figure 2 As shown, it includes a water tank replenishment system, a heating circulation system, a constant pressure water supply system, and a control system. All systems work together to achieve a stable supply of hot water, constant temperature, and constant pressure.

[0021] The control system 10 can realize the functions of automatic water replenishment, automatic heating, automatic constant pressure and fault alarm. Specifically, it includes a PLC controller, touch screen HMI, analog module, circuit breaker, AC contactor, intermediate relay and thermal relay.

[0022] The PLC controller is the control center, with built-in preset programs. It receives analog signals collected by various transmitters and switch signals from equipment status feedback. After processing, it outputs control commands to control the start-up, shutdown, and operation status of each pump group and valve.

[0023] The touchscreen HMI is a human-machine interface that can intuitively display parameters such as pump operating status, water supply temperature, water tank level, motor frequency, current, and voltage. It also supports users in setting various control parameters, such as valve opening level, valve closing level, pump start temperature, pump stop temperature, pump increase frequency, and pump decrease frequency.

[0024] The analog module converts the 4~20mA analog signals collected by the temperature transmitter, level transmitter, and pressure transmitter into digital signals and transmits them to the PLC controller for processing.

[0025] Circuit breakers are used to control the on / off of power circuits for various pump groups, valves, and frequency converters, and to provide overload and short-circuit protection for the circuits.

[0026] The AC contactor receives control commands from the PLC controller to control the energization and de-energization of each pump group motor and the water supply electric valve 5, thereby realizing the start-up and shutdown control of the equipment.

[0027] Intermediate relays amplify, convert, and interlock control signals to ensure the stable operation of the control system, such as interlock protection between manual and automatic modes.

[0028] Thermal relays are used for overload protection of the motors in each pump group. When the motor is overloaded, the thermal relay will trip and cut off the power supply to the motor to prevent damage.

[0029] like Figure 1 and Figure 2 As shown, the water tank replenishment system maintains a constant liquid level in the preheating water tank 7 and the supply water tank 12 to prevent the heating equipment from running dry and being damaged or the water supply from being interrupted due to lack of water. Specifically, it includes a water replenishment electric valve 5, a preheating water tank 7, a preheating water tank level transmitter 9, a supply water tank 12, and a supply water tank level transmitter 13.

[0030] The water supply electric valve 5 receives instructions from the control system 10 and, based on the real-time liquid level data collected by the preheating water tank level transmitter 9, realizes automated control of opening the valve to supply water when the liquid level is low and closing the valve to stop supplying water when the liquid level is high. The valve opening and closing liquid levels can be set via the touch screen HMI, which allows the hot water tank level transmitter 13 to monitor the liquid level of the water supply tank 12 and provides signals for the start and stop control of the hot water transfer pump 8.

[0031] The heating cycle system includes a solar collector heating system, an air heat source heating system, and a rapid water heating system.

[0032] Solar collector 1 absorbs solar heat to heat the internal water. Solar collector temperature transmitter 2 and preheating water tank temperature transmitter 6 collect the outlet water temperature of solar collector 1 and the water temperature in preheating water tank 7, respectively. When the temperature difference between the two reaches the set value or the water temperature in preheating water tank is lower than the set value, the circulation pump group 4 starts to transport the hot water in solar collector 1 to preheating water tank 7 to achieve heat transfer. The exhaust valve 3 is installed at the high point of the pipeline in this embodiment to remove the air released in the pipeline due to the rise in water temperature, and to prevent gas accumulation from causing poor water flow, pressure fluctuation or pipeline deformation.

[0033] The air source heat source heating system is a backup system for solar heating and is suitable for cloudy and rainy weather. When the water temperature in the water supply tank 12 is lower than the set value, the air source heat source pump unit 11 and the air source heat source pump circulation pump 14 are started to heat the water in the preheating water tank 7 and then deliver it to the water supply tank 12 to maintain a constant water temperature in the water supply tank 12.

[0034] The rapid water heating system is an emergency heating device. When the water temperature in the water supply tank 12 does not reach the set value after the air source heat pump unit 11 is started, the heater circulation pump 16 and the rapid water heater 18 are started to raise the water temperature.

[0035] The constant pressure water supply system stably delivers hot water from the water supply tank 12 to the user end, maintaining a constant water supply pressure. Specifically, it includes a hot water variable frequency booster pump 19, a pressure transmitter 20, and an ultraviolet sterilizer 21. The hot water supply pressure transmitter 20 collects the outlet pressure of the water supply pipeline in real time and transmits a 4~20mA analog signal to the control system 10. The ultraviolet sterilizer 21 disinfects the output hot water.

[0036] The PLC controller uses a PID control algorithm to compare the actual pressure value with the set pressure value and outputs a 0~10V control signal to the frequency converter. The frequency converter adjusts the operating frequency of the hot water variable frequency booster pump 19 from 0~50HZ according to the signal to change the pump speed and water supply.

[0037] When the actual pressure is lower than the set value, the frequency of the inverter increases, the speed of the water pump increases, and the water supply increases. When the actual pressure is higher than the set value, the frequency of the inverter decreases, the speed of the water pump slows down, and the water supply decreases.

[0038] When using this embodiment, please refer to the process. Figures 9 to 12 The preheating water tank level transmitter 9 collects the liquid level data of the preheating water tank 7 in real time and transmits it to the PLC controller.

[0039] When the liquid level is lower than the valve opening level set by the touch screen HMI, the PLC controller controls the AC contactor KM9 to open the water supply electric valve 5 and supply water to the preheating water tank 7; when the liquid level reaches the set valve closing level, the PLC controller controls the AC contactor KM10 to close the water supply electric valve 5 and stop water supply.

[0040] The water supply electric valve 5 is equipped with an over-torque limit switch STO, a valve opening limit switch SLO, a closing torque limit switch STC, and a valve closing limit switch SLC to prevent the valve from being damaged due to excessive torque or prolonged energization of the coil.

[0041] The solar collector temperature transmitter 2 and the preheating water tank temperature transmitter 6 collect water temperature data from the solar collector 1 and the preheating water tank 7, respectively, and transmit them to the PLC controller.

[0042] When the temperature difference between the solar collector 1 and the preheating water tank 7 reaches the set value, or when the water temperature in the preheating water tank 7 is lower than the set pump start temperature, the PLC controller controls the solar collector 1 circulation pump group 4 to start, realizing hot water circulation heating between the solar collector 1 and the preheating water tank 7; when the temperature difference is less than the set value, or when the water temperature in the preheating water tank 7 reaches the set pump stop temperature, the circulation pump group 4 stops running.

[0043] When the liquid level in the preheating water tank 7 is lower than the minimum set liquid level, the circulating pump group 4 will automatically stop to prevent the water pump from running dry due to lack of water. The two solar circulating pump groups 4 adopt a one-in-one standby, automatic alternation, and automatic fault reactivation mode to ensure heating continuity.

[0044] The hot water tank level transmitter 13 collects the water level data of the water supply tank 12 in real time. When the water level is lower than the set low water level, the PLC controller first stops the air source heat pump circulation pump 14, and then starts the hot water transition pump 8 and the air source heat pump unit 11 to replenish the water supply tank 12 with the water in the preheated water tank 7 after heating. When the liquid level reaches the set high water level, the hot water transition pump 8 stops running. The two hot water transition pumps 8 adopt a one-in-one standby, automatic alternation, and automatic start-up mode in case of failure.

[0045] When the water level in the water supply tank is normal, the temperature transmitter 15 of the first water supply tank collects water temperature data. If the water temperature is lower than the set value, the PLC controller starts the air source heat pump circulation pump 14 and the air source heat pump unit 11 to heat the water in the water supply tank. If the water temperature is higher than the set value, all the above equipment stops operating.

[0046] When the air source heat pump unit is started, the water temperature collected by the temperature transmitter 17 of the second hot water tank is still lower than the set value. The PLC controller starts the heater circulation pump 16 and the fast water heater 18 to further heat the water to the set temperature and then stops.

[0047] The two air source heat pump circulation pumps 14 and the two heater circulation pumps 16 all adopt a one-in-one standby, automatic alternation, and automatic fault switching mode.

[0048] The hot water supply pressure transmitter 20 collects the outlet pressure data of the water supply pipeline in real time and transmits it to the PLC controller. The PID controller of the PLC controller compares the actual pressure value with the set pressure value and outputs a 0~10V control signal to the frequency converter of the hot water variable frequency booster pump 19. The frequency converter adjusts the output frequency according to the control signal, changes the speed of the hot water variable frequency booster pump 19 to adjust the water supply, and keeps the actual water supply pressure within the set range.

[0049] When the speed of one hot water variable frequency booster pump 19 reaches its maximum value but still cannot meet the water supply pressure demand, the PLC controller starts another hot water variable frequency booster pump 1, and the two pumps adjust their frequencies synchronously. When water consumption decreases and water supply pressure exceeds the set value, the frequency converter reduces the frequency. When the water consumption continues to decrease, the PLC controller shuts down the hot water variable frequency booster pump 19 one by one according to the first-to-first-to-stop principle until only one hot water variable frequency booster pump 19 is running. If only one hot water variable frequency booster pump 19 is running and the water consumption further decreases, turn off this hot water variable frequency booster pump 19 and put it into sleep mode. When the water supply pressure is lower than the set value, the main pump is activated and resumed operation.

[0050] The circuit working principle of this embodiment is as follows: Appendix Figure 3 In this circuit, circuit breakers QF1, QF2, QF3, QF4, QF5, QF6, QF7, and QF8 respectively connect / disconnect the power supply circuits of the first solar circulating pump M1, the second solar circulating pump M2, the first hot water transition pump M3, the second hot water transition pump M4, the first heat source circulating pump M5, the second heat source circulating pump M6, the first heater circulating pump M7, and the second heater circulating pump M8; the main contacts of AC contactors KM1 to KM8 respectively control the energization and de-energization of water pumps M1 to M8.

[0051] Appendix Figure 4 In the middle, circuit breakers QF9 and QF10 are connected to the power input terminals of the first hot water booster pump frequency converter VVVF1 and the second hot water booster pump frequency converter VVVF2, respectively, and are responsible for connecting and disconnecting the power circuits of each frequency converter. The output terminals of frequency converters VVVF1 and VVVF2 are respectively connected to the hot water booster pump motors M9 and M10, which are responsible for controlling and regulating the start-up, shutdown, and operating speed of the hot water booster pump.

[0052] Circuit breaker QF11 is responsible for connecting and disconnecting the power circuit of the solar preheating water tank water supply valve FM1; AC contactor KM9's main contacts control the energization and de-energization of the water supply valve FM1's opening function; AC contactor KM10's main contacts control the energization and de-energization of the water supply valve FM1's closing function.

[0053] Appendix Figure 4 Appendix Figure 5 In the circuit, fuse FU2 is used for overcurrent and short-circuit protection; changeover switch SA1 is a manual / automatic control selector switch. When switch SA1 is in manual mode, the coil of intermediate relay KA8 is energized and the normally open contact is closed. At this time, the auxiliary circuit can be controlled by manual rotary switches SA2~SA9 respectively. Figure 7 The coils of AC contactors KM1~KM8 engage and disengage to control the start and stop of water pumps M1~M8. Manual rotary switches SA10~SA11 control the auxiliary... Figure 7 When the coils of intermediate relays KA1 and KA2 are energized, the normally open contacts of the corresponding intermediate relays are closed, controlling the start of frequency converters VVVF1 and VVVF2 respectively, thereby controlling the start of water pumps M9 and M10.

[0054] Appendix Figure 6 In the middle, manual rotary switch SA12 controls the opening function of the water supply valve FM1 of the solar preheating and preheating water tank, or manual rotary switch SA13 controls the closing function of the water supply valve FM1 of the solar preheating and preheating water tank. When switch SA1 is in the automatic state, the coils of intermediate relays KA5~KA7 are energized and connected, and the normally open contact of intermediate relay KA7 is energized. At this time, it can be controlled by the attached... Figure 7 The programmable logic controller (PLC) automatically controls the coils of AC contactors KM1~KM8 and intermediate relays KA1~KA4 to activate and control the corresponding water pumps / valves to meet the constant pressure water supply function.

[0055] The normally closed contacts of intermediate relays KA5~KA7 are manual / automatic switching interlock contacts to prevent mechanical failure or personal injury caused by malfunction. The power indicator HL1 is the power indicator for the control circuit. The power indicator HL1 is lit when the control circuit is energized and off when there is no power.

[0056] Appendix Figure 6 In the circuit, the switching power supply S converts AC 220V to DC 24V to supply the preheating water tank level transmitter 9 (P1), the preheating water tank temperature transmitter 6 (P2), the collector temperature transmitter 2 (P3), the hot water supply tank level transmitter 13 (P4), the first hot water supply tank temperature transmitter 15 (P5), the second hot water supply tank temperature transmitter 17 (P6), the pressure transmitter 20 (P7), the touch screen HMI, and the analog module AE04.

[0057] Appendix Figure 6In the diagram, STO, SLO, STC, and SLC are internal devices of the water supply electric valve 5 (FM1). STO is the over-torque limit switch, which automatically disconnects and cuts off the external power supply to protect the valve when the valve exceeds the torque limit during opening. SLO is the valve open-to-position limit switch, which automatically disconnects and cuts off the external power supply after the valve is fully opened to prevent the valve coil from overheating and damaging the valve due to prolonged energization. STC is the over-torque limit switch, which automatically disconnects and cuts off the external power supply to protect the valve when the valve exceeds the torque limit during closing. SLC is the valve close-to-position limit switch, which automatically disconnects and cuts off the external power supply after the valve is fully closed to prevent the valve coil from overheating and damaging the valve due to prolonged energization.

[0058] The PLC controller is programmed to implement automatic water replenishment, automatic heating, and automatic constant pressure control functions. Fuse FU1 is used for overcurrent and short-circuit protection of the PLC controller circuit. The touch screen HMI is the display and setting unit of the control system. The collected water pump status, water supply temperature, water tank level, motor frequency, current, and voltage parameters can be displayed intuitively on the touch screen HMI. The corresponding parameters such as valve opening level, valve closing level, pump start temperature, pump stop temperature, pump increase frequency, pump decrease frequency, sleep frequency, pump increase delay, pump decrease delay, sleep delay, and rotation time parameters can also be set through the touch screen HMI.

[0059] The HL2 flashing buzzer is a fault alarm indicator with sound and light. When the PLC controller detects a fault in the control system (such as water pump failure, water shortage, overpressure, or pipe burst), the HL2 flashing buzzer will be activated. The HL2 flashes and emits a buzzing alarm sound to remind staff to check and repair the faulty equipment in time.

[0060] The normally open contacts of AC contactors KM1~KM8 and thermal relays KH1~KH8 are used for water pump operation and fault feedback. The PLC controller automatically adjusts the output based on the received signals. RO1C and RO1B are the control terminals of frequency converters VVVF1 and VVVF2, which are defined as the operation output. When the frequency converter is running, RO1C and RO1B are automatically turned on. When the frequency converter stops, RO1C and RO1B are automatically turned off, and the switch signal is fed back to the PLC controller.

[0061] RO2C and RO2B are the control terminals of the frequency converter VVVF1 and VVVF2. They are defined as fault outputs. When the frequency converter fails, RO2C and RO2B will automatically connect. When the frequency converter is not faulty, RO2C and RO2B will automatically disconnect and feed back the switch signal to the PLC controller. The PLC controller will automatically determine whether to start or stop the corresponding water pump based on the operation / fault signal fed back by the frequency converter.

[0062] B is the communication interface of the PLC controller, which is connected to the control terminals of each water pump frequency converter. The PLC controller communicates with the frequency converters VVVF1 and VVVF2 via MODBUS-RTU to collect various parameters of the hot water booster pump motor in real time, such as motor frequency, operating voltage, and operating current, and display them on the touch screen HMI.

[0063] Appendix Figure 8 The AM04 analog signal acquisition module in the PLC converts the 4~20mA analog signals collected by the preheating water tank level transmitter 9 (P1), preheating water tank temperature transmitter 6 (P2), collector temperature transmitter 2 (P3), hot water supply tank level transmitter 13 (P4), first hot water supply tank temperature transmitter 15 (P5), second hot water supply tank temperature transmitter 17 (P6), and pressure transmitter 20 (P7) into digital signals and outputs them to the PLC controller. The PLC controller performs mathematical calculations on the collected data and displays it intuitively on the touch screen HMI. These data can be compared with the data preset on the touch screen HMI, and the PLC controller controls the start and stop of each water pump and the opening and closing of the valves according to the program.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solar-powered constant-pressure hot water supply system, characterized in that, This includes a water tank replenishment system, a heating and circulation system, a constant pressure water supply system, and a control system. The water tank replenishment system includes a water replenishment electric valve (5), a preheating water tank temperature transmitter (6), a preheating water tank (7), a hot water transfer pump (8), a preheating water tank level transmitter (9), a water supply tank (12), and a water supply tank level transmitter (13). The water replenishment electric valve (5) is installed on the inlet pipe of the preheating water tank (7), the preheating water tank level transmitter (9) is installed inside the preheating water tank (7), and the water supply tank level transmitter (13) is installed inside the water supply tank (12). The heating circulation system includes a solar collector (1), a collector temperature transmitter (2), an exhaust valve (3), a circulation pump group (4), an air source heat pump unit (11), an air source heat pump circulation pump (14), a first hot water tank temperature transmitter (15), a heater circulation pump (16), a second hot water tank temperature transmitter (17), a rapid water heater (18), a hot water frequency conversion pressurization pump (19), and a pressure transmitter (20). The solar collector (1) is connected to the preheated water tank via pipelines. The solar collector (7) is connected to the preheating tank (7). The collector temperature transmitter (2) is installed at the beginning of the pipeline from the solar collector (1) to the preheating tank (7). The preheating tank temperature transmitter (6) is installed at the beginning of the pipeline from the preheating tank (7) to the solar collector (1). The circulating pump set (4) is installed on the pipeline between the output end of the preheating tank (7) and the input end of the solar collector (1). The air source heat pump unit (11) is connected to the preheating tank (7) and the water supply tank (12) through pipelines respectively. The hot water transition pump (8) is installed in the pipeline between the output end of the preheating water tank (7) and the input end of the air source heat pump unit (11). The air source heat pump circulation pump (14) is installed in the pipeline between the output end of the water supply tank (12) and the input end of the air source heat pump unit (11). The first water supply tank temperature transmitter (15) is installed at the beginning of the pipeline from the water supply tank (12) to the air source heat pump unit (11). The output end of the rapid water heater (18) is connected to the water supply tank via a pipeline. The water tank (12) is connected to the input end. The heater circulation pump (16) is installed on the pipeline between the output end of the water supply tank (12) and the input end of the rapid water heater (18). The second water supply tank temperature transmitter (17) is installed at the beginning of the pipeline from the water supply tank (12) to the rapid water heater (18). The hot water frequency conversion booster pump (19) is located on the outlet pipeline of the water supply tank (12). The pressure transmitter (20) is installed on the pipeline at the output end of the hot water frequency conversion booster pump (19). The control system (10) includes a PLC controller, a touch screen, an analog module, a circuit breaker, an AC contactor, an intermediate relay, and a thermal relay. The programmable controller is electrically connected to the touch screen, the analog module, the AC contactor, and the intermediate relay, respectively. The analog module is electrically connected to each temperature transmitter, level transmitter, and pressure transmitter. The AC contactor is electrically connected to each pump. The circuit breaker is used to control the on / off state of the power supply circuit of each device. The thermal relay is used for overload protection of the pump motor.

2. The solar-based constant-pressure hot water supply system according to claim 1, characterized in that, Two units of each of the circulating pump group (4), hot water transition pump (8), air source heat pump circulating pump (14), heater circulating pump (16) and hot water variable frequency booster pump (19) are installed and operate alternately.

3. The solar-based constant-pressure hot water supply system according to claim 1, characterized in that, The water supply electric valve (5) is equipped with an over-torque limit (STO), a valve open-to-position limit (SLO), a closing torque limit (STC), and a valve close-to-position limit (SLC).

4. The solar-based constant-pressure hot water supply system according to claim 1, characterized in that, The PLC controller communicates with the inverter of the hot water variable frequency booster pump (19) via MODBUS-RTU to collect motor frequency, operating voltage and operating current parameters in real time, and the parameters are displayed on the touch screen.

5. The solar-based constant-pressure hot water supply system according to claim 4, characterized in that, The PLC controller performs PID calculations based on the 4~20mA analog signal collected by the pressure transmitter (20) and the set pressure value, and outputs a 0~10V signal to control the frequency converter frequency in order to adjust the water pump speed.

6. The solar-based constant-pressure hot water supply system according to claim 1, characterized in that, The control system (10) is equipped with a manual-automatic switch (SA1). When the manual-automatic switch (SA1) is in manual mode, the start and stop of each pump group and valve are controlled by the rotary switches (SA2~SA13).

7. The solar-based constant-pressure hot water supply system according to claim 1, characterized in that, The control system (10) is equipped with a flashing buzzer (HL2). When a water pump failure, water shortage failure, overpressure failure or pipe burst failure is detected, the flashing buzzer (HL2) will activate an audible and visual alarm.

8. The solar-based constant-pressure hot water supply system according to claim 1, characterized in that, The water supply tank (12) is equipped with an ultraviolet sterilizer (21) at the beginning of the water outlet pipe.

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