A new type of molten salt thermal energy storage water heater

Abstract

The present invention relates to the technical field of water heaters, and particularly relates to a novel molten salt heat storage water heater, comprising: a housing, a plurality of temperature sensors, a molten salt storage and heat exchange integrated tank, an electric heater, a cold water buffer tank, a cold water buffer tank, a plurality of water pipelines, and a water pump. The molten salt storage and heat exchange integrated tank is arranged in the accommodation space and fixedly connected to the bottom wall of the housing. The electric heater is fixedly connected to the upper end of the molten salt storage and heat exchange integrated tank. The cold water buffer tank and the hot water buffer tank are arranged at the upper end of the molten salt storage and heat exchange integrated tank. An inlet, an outlet, an air inlet, a sewage outlet, and an exhaust port are provided on the housing. The plurality of temperature sensors are electrically connected to the controller. The present invention applies molten salt heat storage to the field of water heaters, saving water resources and electric energy, and at the same time reducing potential safety hazards. The water pipelines and the water tank are made of metal materials, reducing the weight of the materials and the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of water heaters, and particularly to a novel molten salt thermal storage water heater. Background Art

[0002] Existing electric water heaters mainly include two types: storage electric water heaters and instant electric water heaters. The power of instant electric water heaters is relatively high. When used during peak electricity consumption hours, the electricity cost is high, and it will also affect the simultaneous use of other electrical appliances, especially high-power electrical appliances, and is prone to overload tripping.

[0003] Storage electric water heaters are generally divided into large-capacity storage electric water heaters and small-capacity storage electric water heaters. Although large-capacity storage electric water heaters can provide a sufficient amount of hot water, they are large in volume, high in cost, long in heating time, high in energy consumption, and long in waiting time for users to take a bath or use hot water; small-capacity storage electric water heaters are difficult to provide a sufficient amount of hot water in a short time. Moreover, since the electric heating tube of an electric water heater is immersed in water, it is very difficult to achieve separation of water and electricity, and there is a risk of electric leakage and electric shock.

[0004] Molten salt refers to salts that are solid at standard temperature and atmospheric pressure and exist in the liquid phase after the temperature rises. The molten body formed after the salt melts, such as the molten bodies of halides, nitrates, and sulfates of alkali metals and alkaline earth metals; molten salt is a molten body composed of metal cations and non-metal anions. There are more than 80 kinds of cations that can form molten salt, and more than 30 kinds of anions. The molten salts combined can reach more than 2,400 kinds. Due to the advantages of "three highs and three lows" such as high use temperature, high thermal stability, high specific heat capacity, high convective heat transfer coefficient, low viscosity, low saturated vapor pressure, and low price, molten salt has become one of the most recognized heat transfer and storage media in the current field of solar thermal power generation.

[0005] Molten salt can be used for solar thermal power generation. This technology uses powerful mirror focusing to collect solar heat to generate steam, which then drives a power generation turbine. The excess heat generated during the day can be used to heat a large amount of salt, which can absorb a considerable amount of heat. When the sun sets or the day is cloudy, the heat stored in the molten salt is used again to generate steam to drive the power generation turbine. And the molten salt only loses nearly 0.5% of its heat after more than 12 hours, and its heat loss is quite small, which also ensures its considerable economy. With the in-depth research and verification of demonstration projects, in addition to the field of solar thermal power generation, more application scenarios have been developed for molten salt energy storage, and it has great application prospects in aspects such as peak shaving and frequency modulation, building heating, valley electricity heating, and wind power consumption.

[0006] The existing molten salt thermal energy storage heating system is designed for centralized heating and steam supply, and the process flow is customized according to specific scenario parameters. The currently emerging molten salt thermal energy storage systems are mainly used to output steam, including molten salt storage tanks, heat exchangers, steam drums, steam pipeline laying, control cabinets, etc., which require a large investment and dedicated site configuration. Summary of the Invention

[0007] To solve the above technical problems, the present invention provides a new type of molten salt thermal energy storage water heater.

[0008] The technical problems solved by the present invention can be realized by the following technical solutions:

[0009] A new type of molten salt thermal energy storage water heater, characterized by comprising:

[0010] A housing, within which there is a receiving space;

[0011] Multiple temperature sensors, which at least include a first temperature sensor, a second temperature sensor, and a third temperature sensor;

[0012] A molten salt storage and heat exchange integrated tank, installed in the receiving space and fixedly connected to the bottom wall of the housing. The first temperature sensor is installed on the molten salt storage and heat exchange integrated tank, and the molten salt storage and heat exchange integrated tank is used for filling molten salt;

[0013] An electric heater, fixedly connected to the upper end of the molten salt storage and heat exchange integrated tank;

[0014] A cold water buffer tank, installed on the upper end of the molten salt storage and heat exchange integrated tank. The second temperature sensor is installed on the cold water buffer tank;

[0015] A hot water buffer tank, installed on the upper end of the molten salt storage and heat exchange integrated tank. The third temperature sensor is installed on the hot water buffer tank;

[0016] Multiple water pipelines, which at least include a first water pipeline, a second water pipeline, a third water pipeline, a fourth water pipeline, a fifth water pipeline, a sixth water pipeline, and a seventh water pipeline, installed in the receiving space;

[0017] The inner surface of the housing is lined with aluminum foil. The housing is provided with a water inlet, a water outlet, an air inlet, a sewage outlet, and an exhaust outlet. The water inlet, the air inlet, and the exhaust outlet are arranged on the upper end face of the housing. The water outlet is fixedly arranged opposite to a mixing water solenoid valve. The second one-way valve is installed on the pipeline between the exhaust outlet and the cold water buffer tank. The sewage outlet is arranged at the bottom of the left end face of the housing; a water pump is installed on the water pipeline and electrically connected to a controller;

[0018] A plurality of the temperature sensors are electrically connected to the controller.

[0019] Preferably, it further includes:

[0020] A plurality of one-way valves, which at least include a first one-way valve, a second one-way valve, a third one-way valve, and a fourth one-way valve, and are installed on the water pipeline;

[0021] A plurality of liquid level switches, which at least include a first liquid level switch, a second liquid level switch, a third liquid level switch, a fourth liquid level switch, and a fifth liquid level switch, and are installed on the water pipeline;

[0022] The plurality of liquid level switches are electrically connected to the controller.

[0023] Preferably, the first water pipeline is connected to the water inlet and extends to be fixedly connected to the cold water buffer tank; a solenoid valve is fixedly installed on the first water pipeline and is electrically connected to the controller.

[0024] Preferably, one end of the second water pipeline is connected to the cold water buffer tank, the other end of the second water pipeline is connected to a first opening of a three-way solenoid valve, a second opening of the three-way solenoid valve is connected to one end of the third water pipeline, a third opening of the three-way solenoid valve is installed with the first one-way valve and extends to the sewage outlet through a pipeline structure, and the three-way solenoid valve is electrically connected to the controller; the other end of the third water pipeline penetrates through the molten salt storage and heat exchange integrated tank and is connected to the hot water buffer tank through the third one-way valve, and the other end of the third water pipeline is also fixedly connected to the air inlet through the fourth one-way valve.

[0025] Preferably, one end of the fourth water pipeline is fixedly connected to the third opening of the three-way solenoid valve through the first liquid level switch, and the other end of the fourth water pipeline is fixedly connected to the cold water buffer tank.

[0026] Preferably, one end of the fifth water pipeline is fixedly connected to the cold water buffer tank, and the other end of the fifth water pipeline is fixedly connected to the hot water buffer tank; the cold water buffer tank is installed with the second liquid level switch and the third liquid level switch, and the hot water buffer tank is installed with the fourth liquid level switch and the fifth liquid level switch.

[0027] Preferably, one end of the sixth water pipeline is connected to the cold water buffer tank, the other end of the sixth water pipeline is connected to one end of the mixing water solenoid valve, the other end of the mixing water solenoid valve is connected to one end of the seventh water pipeline, and the other end of the seventh water pipeline penetrates through the molten salt storage and heat exchange integrated tank and is fixedly connected to the lower end of the hot water buffer tank.

[0028] Preferably, when the electric heater is turned on, the electric heater converts electric power into heat energy and stores it in the molten salt. The first temperature sensor transmits temperature data to the controller. When the temperature of the integrated molten salt storage and heat exchange tank reaches a first preset value, the first temperature sensor transmits a signal to the controller, and the controller controls the electric heater to start heating. When the temperature of the integrated molten salt storage and heat exchange tank reaches a second preset value, the first temperature sensor transmits a signal to the controller, and the controller controls the electric heater to stop heating.

[0029] Preferably, it further includes a cold water heating circuit. Water flows into the cold water buffer tank from the water inlet through the first water pipeline, and then reaches the three-way solenoid valve through the second water pipeline. The first opening and the second opening of the three-way solenoid valve are opened, and the water flows into the third water pipeline of the integrated molten salt storage and heat exchange tank for heat exchange. The hot water enters the hot water buffer tank through the third water pipeline and the third one-way valve.

[0030] Preferably, it further includes a drain standby circuit. By closing the first opening of the three-way solenoid valve, opening the second opening and the third opening of the three-way solenoid valve, and turning on the water pump, the water that is not fully heated in the third water pipeline flows back through the second opening and the third opening of the three-way solenoid valve, the first one-way valve, the water pump and flows through the fourth water pipeline into the cold water buffer tank until the liquid level in the cold water buffer tank is low enough to trigger the first liquid level switch. The first liquid level switch transmits a signal back to the controller, and the controller controls the water pump and the three-way solenoid valve to close.

[0031] The beneficial effects are as follows:

[0032] The present invention can better achieve the separation of water and electricity, and at the same time has a small volume, low cost, short heating time, can provide hot water in a short time, save water resources and electric energy, and reduce potential safety hazards. Brief Description of the Drawings

[0033] Figure 1 It is a schematic internal structure diagram of a new type of molten salt heat storage water heater provided by the present invention;

[0034] Figure 2 It is a front view of a new type of molten salt heat storage water heater provided by the present invention. Detailed Embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0036] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0037] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but it is not limited to the present invention.

[0038] Refer to Figure 1-2 A structural diagram of a novel molten salt heat storage water heater provided by the present invention includes: a housing 1, and an accommodation space is provided inside the housing 1;

[0039] A plurality of temperature sensors, and the temperature sensors at least include a first temperature sensor 8, a second temperature sensor 14, and a third temperature sensor 19;

[0040] A molten salt storage and heat exchange integrated tank 2, which is installed in the accommodation space and fixedly connected to the bottom wall of the housing 1. The first temperature sensor 8 is installed on the molten salt storage and heat exchange integrated tank 2, and the molten salt storage and heat exchange integrated tank 2 is used for filling molten salt;

[0041] An electric heater 7, which is fixedly connected to the upper end of the molten salt storage and heat exchange integrated tank 2;

[0042] A cold water buffer tank 11, which is installed at the upper end of the molten salt storage and heat exchange integrated tank 2, and the second temperature sensor 14 is installed on the cold water buffer tank 11;

[0043] A hot water buffer tank 20, which is installed at the upper end of the molten salt storage and heat exchange integrated tank 2, and the third temperature sensor is installed on the hot water buffer tank 20;

[0044] A plurality of water pipelines, and the water pipelines at least include a first water pipeline T1, a second water pipeline T2, a third water pipeline T3, a fourth water pipeline T4, a fifth water pipeline T5, a sixth water pipeline T6, and a seventh water pipeline T7, which are installed in the accommodation space;

[0045] The inner surface of the housing 1 is pasted with aluminum foil. The housing 1 is provided with a water inlet 23, a water outlet 25, an air inlet 24, a sewage outlet 26, and an exhaust port 27. The water inlet 23, the air inlet 24, and the exhaust port 27 are arranged on the upper end surface of the housing 1. The water outlet 25 is fixedly arranged opposite to a mixing solenoid valve 9. The second one-way valve 13 is installed on the pipeline between the exhaust port 27 and the cold water buffer tank 11. The sewage outlet 26 is arranged at the bottom of the left end surface of the housing 1.

[0046] A water pump 3 is installed on the water pipeline and is electrically connected to a controller 10;

[0047] Multiple temperature sensors are electrically connected to the controller 10.

[0048] Specifically, the independent settings of the cold water buffer tank 11, the hot water buffer tank 20, and the molten salt storage and heat exchange integrated tank 2 isolate the cold water and hot water in different boxes, eliminating temperature interference and maintaining the stability of the hot water temperature. The main body is provided with the molten salt storage and heat exchange integrated tank 2, the cold water buffer tank 11, and the hot water buffer tank 20, and the water pipeline, valves, etc. are arranged according to the positional relationship of the pipelines of the molten salt storage and heat exchange integrated tank 2, the cold water buffer tank 11, and the hot water buffer tank 20 to connect them. At the same time, various data signals are transmitted to the controller 10 and controlled and monitored by the controller 10. In the system, the working pressure is basically 0, and weld cracks and water leakage will not be caused by thermal expansion and contraction. The heat exchange pipeline is filled with steam during long-term operation, which may cause the water tank to explode; both the water pipeline and the water tank are made of metal materials, and the material can be thinned to reduce costs; the molten salt is directly heated by the electric heater 7 to achieve separation of water and electricity and improve energy utilization; due to the general physical law of heat rising and cold falling, the overflow heat of the molten salt storage and heat exchange integrated tank 2 is used to preheat the cold water buffer tank 11 and keep the hot water buffer tank 20 warm. Aluminum foil is installed inside the outer shell 1 to further insulate and reduce the surface temperature of the outer shell 1 by reflecting radiation and scattering.

[0049] Furthermore, it also includes:

[0050] Multiple one-way valves, and the one-way valves at least include a first one-way valve 4, a second one-way valve 13, a third one-way valve 21, and a fourth one-way valve 22, which are installed on the water pipeline;

[0051] Multiple liquid level switches, and the liquid level switches at least include a first liquid level switch 5, a second liquid level switch 15, a third liquid level switch 16, a fourth liquid level switch 17, and a fifth liquid level switch 18, which are installed on the water pipeline;

[0052] Multiple liquid level switches are electrically connected to the controller 10.

[0053] Specifically, the water inlet 23 is connected to the municipal tap water system, and the water inlet is controlled by the solenoid valve 12. The water outlet 25 is connected to the mixing solenoid valve 9 through the sixth water pipeline T6 for mixing and then supplied to users. The cold water buffer tank 11 and the hot water buffer tank 20 have a maximum liquid level limit, and the upper part is a gas phase space. The fifth water pipeline T5 is provided to connect them to make the gas phase spaces of the cold water buffer tank 11 and the hot water buffer tank 20 communicate. The exhaust port 27 discharges the gas to the outside to maintain an atmospheric pressure state.

[0054] Further, the first water pipeline T1 is connected to the water inlet 23 and extends to the cold water buffer tank 11 and is fixedly connected to the cold water buffer tank 11; a solenoid valve 12 is fixedly installed on the first water pipeline T1 and is electrically connected to the controller 10.

[0055] Further, one end of the second water pipeline T2 is connected to the cold water buffer tank 11, the other end of the second water pipeline T2 is connected to the first opening 31 of a three-way solenoid valve 6, the second opening 62 of the three-way solenoid valve 6 is connected to one end of the third water pipeline T3, the third opening 63 of the three-way solenoid valve 6 is equipped with a first check valve 4, and extends to the sewage outlet 26 through a pipeline structure, and the three-way solenoid valve 6 is electrically connected to the controller 10; the other end of the third water pipeline T3 penetrates through the molten salt storage and heat exchange integrated tank 2 and is connected to the hot water buffer tank 20 through a third check valve 21, and the other end of the third water pipeline T3 is also fixedly connected to the air inlet 24 through a fourth check valve 22.

[0056] Further, one end of the fourth water pipeline T4 is fixedly connected to the third opening of the three-way solenoid valve 6 through a first liquid level switch 5, and the other end of the fourth water pipeline T4 is fixedly connected to the cold water buffer tank 11.

[0057] Further, one end of the fifth water pipeline T5 is fixedly connected to the cold water buffer tank 11, and the other end of the fifth water pipeline T5 is fixedly connected to the hot water buffer tank 20; the cold water buffer tank 11 is equipped with a second liquid level switch 15 and a third liquid level switch 16, and the hot water buffer tank 20 is equipped with a fourth liquid level switch 17 and a fifth liquid level switch 18.

[0058] Further, one end of the sixth water pipeline T6 is connected to the cold water buffer tank 11, the other end of the sixth water pipeline T6 is connected to one end of a mixing water solenoid valve 9, the other end of the mixing water solenoid valve 9 is connected to one end of the seventh water pipeline T7, and the other end of the seventh water pipeline T7 penetrates through the molten salt storage and heat exchange integrated tank 2 and is fixedly connected to the lower end of the hot water buffer tank 20.

[0059] Further, when the electric heater 7 is turned on, the electric heater 7 converts electric power into heat energy and stores it in the molten salt. The first temperature sensor 8 transmits temperature data to the controller 10. When the temperature of the molten salt storage and heat exchange integrated tank 2 reaches a first preset value, the first temperature sensor 8 transmits a signal to the controller 10, and the controller 10 controls the electric heater 7 to start heating; when the temperature of the molten salt storage and heat exchange integrated tank 2 reaches a second preset value, the first temperature sensor 8 transmits a signal to the controller 10, and the controller 10 controls the electric heater 7 to stop heating.

[0060] Specifically, during the off-peak electricity period at night, the electric heater 7 is turned on to convert electric power into heat energy and store it in the molten salt. A first temperature sensor 8 is provided on the integrated molten salt storage and heat exchange tank 2. The first temperature sensor 8 transmits temperature data to the controller 10. When the temperature reaches the set minimum temperature, the first temperature sensor 8 transmits a signal to the controller 10, and the controller 10 controls the electric heater 7 to start heating. When the temperature reaches the set maximum temperature, the first temperature sensor 8 transmits a signal to the controller 10, and the controller 10 controls the electric heater 7 to stop heating.

[0061] During the peak electricity period when energy is used, the cold water heating circuit is turned on. Water flows through the integrated molten salt storage and heat exchange tank 2, and the heat of the integrated molten salt storage and heat exchange tank 2 is transferred to the medium water through heat exchange to obtain the required hot water. Then the water will enter the hot water buffer tank 20 through the water pipeline and be temperature-adjusted by the mixing solenoid valve 9 to supply the constant temperature hot water to the user for use.

[0062] Furthermore, it also includes a cold water heating circuit. Water flows through the first water pipeline T1 and enters the cold water buffer tank 11 from the water inlet 23, and then reaches the three-way solenoid valve 6 through the second water pipeline T2. The first opening 61 and the second opening 62 of the three-way solenoid valve 6 are opened, and the water flows into the third water pipeline T3 of the integrated molten salt storage and heat exchange tank 2 for heat exchange. The hot water enters the hot water buffer tank 20 through the third water pipeline T3 and the third one-way valve 21.

[0063] Specifically, the municipal tap water system flows into the cold water buffer tank 11 from the water inlet 23 through the first water pipeline T1, and then reaches the three-way solenoid valve 6 through the second water pipeline T2. The first opening 61 and the second opening 62 of the three-way solenoid valve 6 are opened, and the water flows into the third water pipeline T3 of the integrated molten salt storage and heat exchange tank 2 for heat exchange. The hot water enters the hot water buffer tank 20 through the third water pipeline T3 and the third one-way valve 21. When water enters, the gas in the third water pipeline T3 is squeezed by the incoming water and enters the hot water buffer tank 20 through the third one-way valve 21, and then enters the cold water buffer tank 11 through the fifth water pipeline T5 between the hot water buffer tank 20 and the cold water buffer tank 11 to preheat the cold water. The cooled gas enters the gas phase space of the cold water buffer tank 11. If there is pressure, it triggers the second one-way valve 13, and the gas enters the atmospheric environment to maintain the normal pressure state. When the user uses water, the hot water in the hot water buffer tank 20 flows through the seventh water pipeline T7 to reach the mixing solenoid valve 9. At the same time, the cold water in the cold water buffer tank 11 flows through the sixth water pipeline T6 to reach the mixing solenoid valve 9, and the hot water that meets the user's requirements flows out through temperature adjustment and mixing.

[0064] Further, it also includes a drain standby circuit. By closing the first opening 61 of the three-way solenoid valve 6, opening the second opening 62 and the third opening 63 of the three-way solenoid valve 6, and turning on the water pump 3, the water that is not fully heated in the third water pipeline T3 flows back through the second opening 62 and the third opening 63 of the three-way solenoid valve 6, the first one-way valve 4, the water pump 3 and flows through the fourth water pipeline T4 into the cold water buffer tank 11 until the liquid level in the third water pipeline T3 is low enough to trigger the first liquid level switch 5. The first liquid level switch 5 sends a signal back to the controller 10, and the controller 10 controls the water pump 3 and the three-way solenoid valve 6 to close.

[0065] Specifically, in the standby state of suspending water use or when the hot water tank is full and the water consumption is very small, it is necessary to drain the water pipeline. By closing the first opening 61 of the three-way solenoid valve 6, opening the second opening 62 and the third opening 63 of the three-way solenoid valve 6, and turning on the water pump 3, the water that is not fully heated in the third water pipeline T3 flows back through the second opening 62 and the third opening 63 of the three-way solenoid valve 6, the first one-way valve 4, the water pump 3 and flows through the fourth water pipeline T4 into the cold water buffer tank 11 until the liquid level in the third water pipeline T3 is low enough to trigger the first liquid level switch 5. The first liquid level switch 5 sends a signal back to the controller 10, and the controller 10 controls the water pump 3 and the three-way solenoid valve 6 to close; since the third one-way valve 21 is closed, negative pressure is generated when the flowing water is drained, triggering the fourth one-way valve at the top to intake air, and the air enters the space of the third water pipeline T3, making the third water pipeline T3 inflated and in standby for heat preservation. If the gas heat exchange expands to generate pressure, the hot air enters the hot water buffer tank 20 through the third one-way valve 21, enters the cold water buffer tank 11 through the fifth water pipeline T5 between the hot water buffer tank 20 and the cold water buffer tank 11 to preheat the cold water, and the cooled gas enters the gas phase space of the cold water buffer tank 11. If there is pressure, it triggers the second one-way valve 13, and the gas enters the atmospheric environment to maintain the normal pressure state.

[0066] In a preferred embodiment of the present invention, taking a barbershop as an example, it takes 10 minutes to wash one's hair, and 2 liters of water are used before and after the haircut. If 50 customers are received daily, then 100L of hot water is required. If 250 customers are received, 500L of hot water is required. For large barbershops, it is more than 1000L. This calculation example demonstrates according to 100L and 1000L:

[0067] It is calculated that: the energy required for 100L of 50°C hot water is 21000KJ, and about 58kg of molten salt is required. The volume is 33L.

[0068] Converting 21000KJ into electricity is about 60Kwh. For 1000L, it is also 60Kwh. If the valley electricity duration at night is 8 hours, then the electric heating power of the electric heater can be calculated as 750w, and for 1000L, it is 7.5Kw.

[0069] According to the building water supply and drainage design specifications, the rated water flow rate of a sanitary ware is 0.15L / S, that is, 9L / min. The flow rate of a common small handheld shower is about 5L / Min. Assuming that the demand system produces 10L / min of hot water, the enthalpy value of 50℃ hot water is 210KJ / Kg.

[0070] Perform heat balance: Q = W (I out - I in) = 10 L / min * 210 KJ / Kg = 2100 KJ / min.

[0071] Ignoring radiation heat transfer, the heat transfer mode is: convection-conduction-conduction.

[0072] The thermal conductivity of stainless steel is 10-30W / (m.℃), and it is 16.2W / (m.℃) at 304℃; the thermal conductivity of air is 0.024W / (m.℃), which is relatively small, which is not conducive to thermal conduction, but is conducive to thermal insulation; the thermal conductivity of water at 50℃ is 0.566W / (m.℃), and at 0℃ it is: 0.55W / (m.℃); the thermal conductivity of molten salt: 150℃ is 0.462W / (m.℃), and 400℃ is 0.330W / (m.℃).

[0073] It can be seen that the thermal conductivity of air is extremely low, so the emptying loop uses air to fill the water pipe, which is safe and has a heat preservation effect. The heat transfer coefficient changes with the temperature, and heat transfer is a dynamic process. Increasing the heat exchange area is conducive to increasing the heat exchange load, but when the heat exchange area increases to a certain extent, the Reynolds number becomes smaller, and the turbulent flow may change to laminar flow, which will reduce the heat transfer coefficient and reduce the heat load. This effect is sometimes even worse than the effect of heat exchange with the original area. The heat exchange efficiency is affected by the flow pattern, which is related to the Reynolds number, which is related to the flow rate, and the flow rate is related to the pipe diameter.

[0074] Heat transfer calculation: effective heat exchange area A=Q / kK*△tm, where: A is the effective heat exchange area of ​​the heat exchanger; Q is the total heat exchange capacity; k is the fouling coefficient, generally 0.8-0.9; K is the heat transfer coefficient; △tm is the logarithmic mean temperature difference. According to heat exchange area=pipe diameter*pipe length, the flow rate, Reynolds number, heat transfer coefficient, etc. are calculated by reverse calculation based on the pipe diameter, and the pipe diameter and length of the water pipe are adjusted until the required flow rate is met.

[0075] In summary, flow rate and velocity are design conditions. The structure of the heat exchange tube is designed according to the required hot water flow rate to ensure that the required hot water flow rate is met. The system will use the target flow rate, such as 9L / min or other parameters of 50℃ hot water, to reversely calculate the required length of the heat exchange tube. By increasing the local thickness of the cylinder and improving the flow state of the pipeline to laminar flow through soft streamlines, a low heat transfer coefficient is obtained to achieve the result of slow release of heat energy.

[0076] In a preferred embodiment, an automatic water replenishing mechanism is provided in the cold water buffer tank 11. When the water level rises to the highest liquid level line, the second liquid level switch 15 is triggered, and the trigger signal is sent back to the controller 10. The controller 10 controls the solenoid valve 12 to close according to the trigger signal to stop the water inlet; when the water level in the upper part of the cold water buffer tank drops to the lowest liquid level line, the third liquid level switch 16 is triggered, and the trigger signal is sent back to the controller 10. The controller 10 controls the solenoid valve 12 to open according to the trigger signal to supplement cold water.

[0077] An automatic water replenishing mechanism is also provided in the hot water buffer tank 20. When the water level rises to a certain height, the fifth liquid level switch 18 is triggered, and the trigger signal is sent back to the controller 10. The controller 10 controls the three-way solenoid valve 6 to close the first opening 61 of the three-way solenoid valve 6 and open the second opening 62 and the third opening 63 of the three-way solenoid valve 6, and turns on the water pump 3; when discharging hot water, the water level in the upper part of the water tank drops to the lowest liquid level line, the fourth liquid level switch 17 is triggered, and the trigger signal is sent back to the controller 10. The controller 10 controls the first one-way valve 4 to open the third opening 63 of the three-way solenoid valve 6 to start the process of supplementing hot water during the water heat exchange process.

[0078] The molten salt storage and heat exchange integrated tank 2 needs to complete two processes of heat charging and heat discharging during the operation of the whole system. A water pipeline for heat exchange is provided in the molten salt storage and heat exchange integrated tank 2, and an electric heater 7 is installed inside. Water flows through the coil and exchanges heat with the high-temperature liquid molten salt in the molten salt storage and heat exchange integrated tank 2 to obtain hot water. Before the operation of the new molten salt thermal storage water heater, it is necessary to use off-peak electricity to heat the molten salt in the molten salt storage and heat exchange integrated tank 2 to the set value, which is the heat charging process.

[0079] The above are only preferred embodiments of the present invention, and do not limit the implementation manners and protection scope of the present invention accordingly. For those skilled in the art, it should be able to realize that all equivalent replacements and obvious changes made by using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A new type of molten salt thermal energy storage water heater, characterized in that, Comprising: A housing, within which there is a receiving space; Multiple temperature sensors, which at least include a first temperature sensor, a second temperature sensor, and a third temperature sensor; A molten salt storage and heat exchange integrated tank, installed within the receiving space and fixedly connected to the bottom wall of the housing. The first temperature sensor is installed on the molten salt storage and heat exchange integrated tank, and the molten salt storage and heat exchange integrated tank is used for filling molten salt; An electric heater, fixedly connected to the upper end of the molten salt storage and heat exchange integrated tank; A cold water buffer tank, installed at the upper end of the molten salt storage and heat exchange integrated tank. The second temperature sensor is installed on the cold water buffer tank; A hot water buffer tank, installed at the upper end of the molten salt storage and heat exchange integrated tank. The third temperature sensor is installed on the hot water buffer tank; Multiple water pipelines, which at least include a first water pipeline, a second water pipeline, a third water pipeline, a fourth water pipeline, a fifth water pipeline, a sixth water pipeline, and a seventh water pipeline, installed within the receiving space; Multiple one-way valves, which at least include a first one-way valve, a second one-way valve, a third one-way valve, and a fourth one-way valve, installed on the water pipelines; Multiple liquid level switches, which at least include a first liquid level switch, a second liquid level switch, a third liquid level switch, a fourth liquid level switch, and a fifth liquid level switch, installed on the water pipelines; The multiple liquid level switches are electrically connected to a controller; The inner surface of the housing is lined with aluminum foil. The housing is provided with a water inlet, a water outlet, an air inlet, a sewage outlet, and an exhaust outlet. The water inlet, the air inlet, and the exhaust outlet are arranged on the upper end face of the housing. The water outlet is fixedly arranged opposite to a mixing water solenoid valve. The second one-way valve is installed on the pipeline between the exhaust outlet and the cold water buffer tank. The sewage outlet is arranged at the bottom of the left end face of the housing; A water pump, installed on the water pipeline and electrically connected to a controller; The multiple temperature sensors are electrically connected to the controller; One end of the second water pipeline is connected to the cold water buffer tank, and the other end of the second water pipeline is connected to the first opening of a three-way solenoid valve. The second opening of the three-way solenoid valve is connected to one end of the third water pipeline. The third opening of the three-way solenoid valve is equipped with the first one-way valve and extends to the sewage outlet through a pipeline structure. The three-way solenoid valve is electrically connected to the controller; The other end of the third water pipeline penetrates through the molten salt storage and heat exchange integrated tank and is connected to the hot water buffer tank through the third one-way valve. The other end of the third water pipeline is also fixedly connected to the air inlet through the fourth one-way valve; It further includes a standby loop. By closing the first opening of the three-way solenoid valve, opening the second and third openings of the three-way solenoid valve, and starting the water pump, the incompletely heated water in the third water pipeline flows back through the second and third openings of the three-way solenoid valve, the first one-way valve, the water pump and through the fourth water pipeline into the cold water buffer tank until the liquid level in the third water pipeline drops to trigger the first liquid level switch. The first liquid level switch sends a signal back to the controller, and the controller controls the water pump and the three-way solenoid valve to close. One end of the fourth water pipeline is fixedly connected to the third opening of the three-way solenoid valve through the first liquid level switch, and the other end of the fourth water pipeline is fixedly connected to the cold water buffer tank.

2. The novel molten salt heat storage water heater according to claim 1, characterized in that, The first water pipeline is connected to the water inlet and extends to the cold water buffer tank and is fixedly connected to the cold water buffer tank; a solenoid valve fixing device is arranged on the first water pipeline and is electrically connected to the controller.

3. A novel molten salt heat storage water heater according to claim 1, characterized in that, One end of the fifth water pipeline is fixedly connected to the cold water buffer tank, and the other end of the fifth water pipeline is fixedly connected to the hot water buffer tank; the cold water buffer tank is provided with the second liquid level switch and the third liquid level switch, and the hot water buffer tank is provided with the fourth liquid level switch and the fifth liquid level switch.

4. A novel molten salt heat storage water heater according to claim 1, characterized in that, One end of the sixth water pipeline is connected to the cold water buffer tank, the other end of the sixth water pipeline is connected to one end of the mixing solenoid valve, the other end of the mixing solenoid valve is connected to one end of the seventh water pipeline, and the other end of the seventh water pipeline penetrates through the molten salt storage and heat exchange integrated tank and is fixedly connected to the lower end of the hot water buffer tank.

5. A novel molten salt heat storage water heater according to claim 1, characterized in that, When the electric heater is turned on, the electric heater converts electric energy into heat energy and stores it in the molten salt. The first temperature sensor transmits temperature data to the controller. When the temperature of the molten salt storage and heat exchange integrated tank reaches a first preset value, the first temperature sensor transmits a signal to the controller, and the controller controls the electric heater to start heating; when the temperature of the molten salt storage and heat exchange integrated tank reaches a second preset value, the first temperature sensor transmits a signal to the controller, and the controller controls the electric heater to stop heating.

6. A novel molten salt thermal energy storage water heater according to claim 1, characterized in that, It further includes a cold water heating loop. Water flows into the cold water buffer tank from the water inlet through the first water pipeline, then reaches the three-way solenoid valve through the second water pipeline. The first and second openings of the three-way solenoid valve are opened, and the water flows into the third water pipeline of the molten salt storage and heat exchange integrated tank for heat exchange. The hot water enters the hot water buffer tank through the third water pipeline and the third one-way valve.

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