CN103913000B - A kind of phase-change thermal storage solar water heater with water route one-way circulation structure - Google Patents

Abstract

The invention relates to a phase-change heat storage solar water heater with a waterway unidirectional circulation structure, which includes a phase-change heat storage solar water heater, an overheat protection device with an evaporation medium inside, and a waterway unidirectional circulation structure. The overheat protection device includes The evaporating pipe and the condensing pipe, the outlet end of the evaporating pipe is connected with the inlet end of the condensing pipe, the outlet end of the condensing pipe is connected with the inlet end of the evaporating pipe, and the evaporating pipe is buried in the phase change heat storage solar water heater, and the water circuit unidirectional circulation structure includes Water inlet pipe, water return pipe, heat exchange pipe and one-way conduction element, water inlet pipe and return pipe are connected by heat exchange pipe, evaporation pipe and heat exchange pipe are in heat transfer contact, heat exchange pipe is in phase change with phase change heat storage solar water heater The heat storage material performs heat exchange; the present invention can realize automatic circulation in the absence of water source and power supply, so that the internal temperature of the phase change heat storage solar water heater will not be too high, and ensure that the temperature of the water heater is uniform everywhere, which helps Enhance heat dissipation.

Description

A phase-change heat storage solar water heater with a waterway unidirectional circulation structure

[technical field]

The invention relates to the technical field of solar water heaters, in particular to a phase-change thermal storage solar water heater with a waterway unidirectional circulation structure.

[Background technique]

With the rapid development of China's economy and the continuous improvement of people's living standards, the demand for energy is also increasing. The current energy consumption is mainly fossil fuels such as coal, oil and natural gas. Due to the limited oil reserves in our country, nearly 50% of crude oil is currently imported, and coal is still the main source of fuel and power in our country. The environmental problems caused by coal burning have become a problem that must be taken seriously in our sustainable development strategy. Solar energy is a huge energy source that does not pollute the environment. The solar energy that the earth obtains every second is equivalent to the energy emitted by burning 5 million tons of high-quality coal.

my country is one of the countries with the most abundant solar energy in the world. The total amount of solar radiation in my country is greater than 5.02 million kilojoules square meters, and the area with annual sunshine hours of 2,200 hours accounts for more than 2/3 of my country's land area, especially in the western region. The sunshine time is more than 3000 hours. my country has made remarkable achievements in the use of solar energy, among which the solar water heater industry has developed particularly rapidly and is becoming a new industry.

In recent years, solar water heaters have grown at an annual rate of 20% to 30%. my country's solar energy industry started relatively late and is still in the early stages of development. There is a big gap with foreign counterparts. At present, the application of solar energy is mainly concentrated in the utilization of low-quality solar energy. Glass vacuum tube solar water heater and heat pipe glass vacuum tube solar water heater, etc. In recent years, there are also low-end solar collectors using plastic-water pipes. The disadvantages of these low-end solar water heaters, which use vacuum glass plates/tubes to directly discharge water, are poor thermal insulation performance, many joints are prone to water leakage, poor resistance to low temperature, fragile and easy to burst, large in size, heavy in weight, and low in thermal efficiency.

Phase change energy storage and technology can store energy in phase change materials (PhaseChangeMaterials, PCMs) in the form of phase change latent heat, and realize energy conversion between different time and space. Utilizing the phase change latent heat of phase change materials to realize energy storage and utilization is helpful to improve energy utilization efficiency and develop renewable energy. It is a very active frontier research direction in the fields of energy science and material science in recent years. Compared with sensible heat energy storage technology, phase change energy storage technology has the advantages of high energy storage density, small size, constant temperature control, remarkable energy saving effect, wide selection range of phase change temperature, and easy control. Heating and air conditioning, optimization of power supply systems, medical engineering, military engineering, thermal storage buildings, and clothing for extreme environments hold great promise.

Existing anti-overheating measures for phase-change thermal storage solar water heaters generally use T/P valves to fix temperature and drain water or sunshade curtains to prevent overheating; using T/P valves to fix temperature and waterproof needs to ensure that phase-change thermal storage solar water heaters and tap water are unimpeded. When the house has not been delivered or is unoccupied for a long time, there is a danger of overheating caused by the lack of tap water, and a large amount of hot water needs to be discharged when the overheating protection is activated, resulting in waste; the automatic sunshade method is used, the system is complicated, the investment is large, the failure rate is high, and the consumption is high. Electric energy; and the above two measures all have the disadvantage of being unable to ensure that the phase change heat storage solar water heater has a uniform temperature throughout.

[Content of the invention]

The purpose of the present invention is to solve the above-mentioned deficiencies and provide a phase-change thermal storage solar water heater with a waterway unidirectional circulation structure, which can realize automatic circulation not only in the absence of water source and power supply, but also make the phase-change thermal storage solar water heater The internal temperature will not be too high, and it ensures that the temperature of the water heater is uniform throughout, and helps to strengthen heat dissipation.

In order to achieve the above purpose, a phase-change heat storage solar water heater with a waterway unidirectional circulation structure is designed, which includes a phase-change heat storage solar water heater, an overheat protection device with an evaporation medium inside, and a waterway unidirectional circulation structure. The overheating protection device is installed on the upper part of the phase change heat storage solar water heater, and the one-way circulation structure of the water channel is arranged inside the phase change heat storage solar water heater. Condensate into a condensing tube for evaporating medium, the outlet end of the evaporating tube communicates with the inlet end of the condensing tube, the outlet end of the condensing tube communicates with the inlet end of the evaporating tube, and the evaporating tube is fully or partially buried in the phase change storage In the thermal solar water heater, the waterway unidirectional circulation structure includes the water inlet pipe entering the phase change heat storage solar water heater, the return water pipe flowing out of the phase change heat storage solar water heater, the heat exchange pipe and the one-way conducting element, the water inlet pipe and the return pipe The water pipes are connected through heat exchange pipes, the inlet pipe and the return pipe are respectively equipped with one-way conduction elements, the evaporation pipes are in heat transfer contact with the heat exchange pipes, and the heat exchange pipes are in contact with the phase change heat storage solar water heater. The heat storage material is used for heat exchange.

The unidirectional conduction element includes a unidirectional conduction element 1 and a unidirectional conduction element 2, the unidirectional conduction element 1 is installed on the water inlet pipe, the unidirectional conduction element 2 is installed on the return pipe, and the unidirectional conduction element 2 is installed on the water return pipe. The water inlet is connected to the water outlet of the one-way conducting element one, and the water outlet of the return pipe is connected to the water inlet of the one-way conducting element two.

The water inlet of the first unidirectional conducting element communicates with the water outlet of the second unidirectional conducting element.

The outlet end of the condensing pipe is connected to the inlet end of the evaporating pipe through a pipeline, or the inlet end of the condensing pipe is connected to the outlet end of the evaporating pipe through a pipeline, and an air tank is connected to the pipeline or the condensing pipe.

The water supply pipe and the air tank 2 are communicated between the water inlet of the first unidirectional conductive element and the water outlet of the second unidirectional conductive element.

The one-way conducting element is a one-way valve or an electric valve.

The evaporation medium is a material with a boiling point less than or equal to 150°C.

The evaporation medium is water, alcohol, antifreeze, liquid ammonia, ether, acetone, methanol or isopropanol.

The evaporation tube is copper tube, aluminum tube, stainless steel tube or finned tube.

The condensation pipe is a copper pipe, an aluminum pipe, a stainless steel pipe or a finned pipe.

Compared with the prior art, the present invention has a simple structure. An overheat protection device filled with evaporation medium is installed on the upper part of the phase change heat storage solar water heater. In the case of water source and power supply, it will automatically circulate to ensure that the internal temperature of the phase change thermal storage solar water heater will not be too high, which can save water and electricity; moreover, the phase change thermal storage solar water heater is equipped with a waterway unidirectional circulation structure inside, and the waterway is single The directional circulation structure adopts the water inlet pipe, heat exchange pipe, return water pipe and two unidirectional conduction elements to form a circulation loop, so that when the temperature of the water heater reaches a certain value, the pressure of the water in the heat exchange pipe increases due to heating, and at the same time, the evaporation pipe continues to dissipate heat. This reduces the temperature and cooling pressure of the part of the heat exchange tube that is in contact with it, forms a pressure difference in the circuit, and promotes the unidirectional circulation of water in the circuit, ensuring uniform temperature throughout the water heater and helping to strengthen heat dissipation; in addition, the air tank It is set up for strong radiation, when the amount of steam is large, because the gas can be compressed, too much air will enter the air tank to form compressed air, thus forming a buffer, and the performance is very reliable.

[Description of drawings]

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of waterway unidirectional circulation structure among the present invention;

In the figure: 1, phase change heat storage solar water heater 2, evaporation pipe 3, air tank 4, condensation pipe 5, pipeline 6, return pipe 7, water inlet pipe 8, one-way conduction element two 9, one-way conduction element one 10 , Heat exchange tube.

[detailed description]

Below in conjunction with accompanying drawing, the present invention will be further described as follows:

As shown in the drawings, the present invention includes: a phase change heat storage solar water heater 1, an overheat protection device with an evaporation medium inside and a waterway unidirectional circulation structure, the overheat protection device is installed on the upper part of the phase change heat storage solar water heater, The waterway one-way circulation structure is set inside the phase change heat storage solar water heater. The overheating protection device includes the evaporation tube 2 that evaporates the evaporation medium into a gas and the condensation tube 4 that condenses the gas into an evaporation medium. The inlet end of the pipe is connected, the outlet end of the condensation pipe is connected with the inlet end of the evaporating pipe, and the evaporating pipe is completely or partially buried in the phase change heat storage solar water heater. 7. The return pipe flowing out of the phase-change heat storage solar water heater 6. The heat exchange pipe 10 that connects the water inlet pipe and the return water pipe and performs heat exchange with the phase-change heat storage material in the phase-change heat storage solar water heater and a plurality of unidirectional conductive elements , the one-way conduction element can be but not limited to a one-way valve or an electric valve, the water inlet pipe and the return pipe are connected through a heat exchange pipe inside the phase-change heat storage solar water heater, and a one-way conduction element is installed on the water inlet pipe and the return pipe respectively, The evaporation tube is in heat transfer contact with the heat exchange tube.

In the present invention, the unidirectional conduction element comprises a unidirectional conduction element 9 and a unidirectional conduction element 2 8, the unidirectional conduction element 1 is installed on the water inlet pipe, the unidirectional conduction element 2 is installed on the return water pipe, and the water inlet of the water inlet pipe Connect the water outlet of the one-way conducting element one, and connect the water outlet of the return pipe to the water inlet of the one-way conducting element two. The water inlet of the unidirectional conductive element 1 connected to the water inlet pipe is connected to the water outlet of the unidirectional conductive element 2 connected to the return pipe, and the water supply pipe and the air tank 2 can be connected in the middle. The outlet end of the condensation pipe is connected to the inlet end of the evaporation pipe through a pipeline 5, or the inlet end of the condensation pipe is connected to the outlet end of the evaporation pipe through a pipeline. The air tank 3 is connected to the pipeline or the condensation pipe. This pipeline is for evaporation The connection between the tube and the condenser tube is convenient; the evaporating medium is a material with a boiling point less than or equal to 150°C, such as but not limited to water, alcohol, antifreeze, liquid ammonia, ether, acetone, methanol or isopropanol, and the evaporating tube It can be but not limited to copper tube, aluminum tube, stainless steel tube or finned tube, and the condensation tube can be but not limited to copper tube, aluminum tube, stainless steel tube or finned tube.

The characteristics of the phase-change thermal storage solar water heater are: when the user does not use it, there is no water flow inside the phase-change thermal storage solar water heater, and the solar radiation energy is converted into thermal energy and stored in the phase-change thermal storage material. When the user uses it, the water flows through the phase change heat storage solar water heater, the water flow and the phase change heat storage material perform heat exchange, and the heat is carried out of the phase change heat storage solar water heater along with the water flow. If the radiation is strong and the user is not using the phase change heat storage solar water heater, the energy accumulation of the phase change heat storage material will increase too much, which will increase the temperature of the phase change heat storage material, which will damage the phase change heat storage due to overheating solar water heaters. Therefore, the present invention designs a circulation loop composed of evaporation tubes and condensation tubes. Since the evaporation tubes are buried in the phase-change thermal storage solar water heater, the evaporation tubes are in close contact with the heat exchange tubes inside the water heater. As the phase-change thermal storage solar water heater As the temperature of the phase-change heat storage material in the water heater increases, the temperature of the evaporation medium in the evaporation tube will also increase. When the temperature of the water heater reaches a certain value, the evaporation medium becomes steam to take away heat, and then the steam enters the condensation tube. The condensing pipe is set outside the phase change heat storage solar water heater, and the structure of the condensing pipe is that the tubular member is equipped with multiple cooling fins, so the steam condenses in the condensing pipe to become a liquid evaporation medium, thereby passing through the phase change heat storage material. Too much heat will be taken out of the phase change heat storage solar water heater due to the phase change of the evaporation medium, and finally prevent the internal temperature of the solar water heater from being too high through self-circulation.

In the present invention, the purpose of setting up the air tank on the pipeline or condensing pipe is to cause an impact on the circuit formed by the evaporating pipe and the condensing pipe due to the excessive amount of steam formed by the evaporation of the evaporating medium when the radiation is strong. , When the amount of steam is large, because the gas can be compressed, too much air will enter the air tank to form compressed air, thus forming a buffer.

The unidirectional circulating waterway designed by the present invention is composed of water inlet pipe, heat exchange pipe, return water pipe, unidirectional conductive element 1 and unidirectional conductive element 2. When the temperature of the water heater reaches a certain value, the pressure of the water in the heat exchange tube increases due to heating, and at the same time, the evaporator tube continues to dissipate heat so that the part of the heat exchange tube in contact with it cools down and the cooling pressure decreases, forming a pressure difference in the circuit. The water is pushed to circulate in one direction in the loop, thereby ensuring that the temperature of the phase-change heat-storage material in the phase-change heat-storage solar water heater is uniform everywhere.

The present invention is not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the present invention. within the scope of protection.

Claims (8)

1. A phase-change heat storage solar water heater with a waterway unidirectional circulation structure, characterized in that: it comprises a phase-change heat storage solar water heater, an internal overheating protection device with an evaporation medium and a waterway unidirectional circulation structure, so The overheat protection device is installed on the upper part of the phase change heat storage solar water heater, and the one-way circulation structure of the water channel is arranged inside the phase change heat storage solar water heater. The body condenses into a condensation tube of the evaporation medium, the outlet end of the evaporation tube is connected with the inlet end of the condensation tube, the outlet end of the condensation tube is connected with the inlet end of the evaporation tube, and the evaporation tube is completely or partially buried in the phase change In the heat storage solar water heater, the waterway unidirectional circulation structure includes the water inlet pipe entering the phase change heat storage solar water heater, the return water pipe flowing out of the phase change heat storage solar water heater, the heat exchange pipe and the one-way conducting element. The return pipe is connected by a heat exchange pipe, the inlet pipe and the return pipe are respectively equipped with one-way conducting elements, the evaporation pipe is in heat transfer contact with the heat exchange pipe, and the heat exchange pipe is in contact with the phase change heat storage solar water heater. phase change heat storage material for heat exchange, the unidirectional conductive element includes unidirectional conductive element 1 and unidirectional conductive element 2, the unidirectional conductive element 1 is installed on the water inlet pipe, and the unidirectional conductive element 2 is installed on the On the return pipe, the water inlet of the water inlet pipe is connected to the water outlet of the one-way conduction element one, the water outlet of the return water pipe is connected to the water inlet of the two-way conduction element two, and the water inlet of the one-way conduction element one is connected to the one-way conduction element one. It is connected to the water outlet of the conduction element 2. 2. The phase change heat storage solar water heater according to claim 1, characterized in that: the outlet end of the condensation pipe is connected to the inlet end of the evaporation pipe through a pipeline, or the inlet end of the condensation pipe is connected to the evaporation pipe through a pipeline. At the outlet end of the pipe, the pipeline or condensing pipe is connected with an air tank. 3. The phase-change heat storage solar water heater according to claim 2, characterized in that: the water inlet of the one-way conducting element one and the water outlet of the one-way conducting element two are connected with a water supply pipe and an air tank two. 4. The phase change heat storage solar water heater according to claim 3, characterized in that: the one-way conducting element is a one-way valve or an electric valve. 5. The phase change heat storage solar water heater according to claim 4, characterized in that: the evaporation medium is a material with a boiling point less than or equal to 150°C. 6. The phase-change thermal storage solar water heater according to claim 5, wherein the evaporating medium is water, alcohol, antifreeze, liquid ammonia, ether, acetone, methanol or isopropanol. 7. The phase-change thermal storage solar water heater as claimed in claim 6, wherein the evaporation tube is a copper tube, an aluminum tube, a stainless steel tube or a finned tube. 8. The phase-change heat storage solar water heater according to claim 7, wherein the condensing pipe is a copper pipe, an aluminum pipe, a stainless steel pipe or a finned pipe.