An electric heat storage device for heating with multiple heat sources

Abstract

The embodiment of the present invention provides an electric heat storage device with multiple heat sources for heating, which relates to the field of thermal energy technology. It includes a heat preservation cavity, a heat energy driven heat pump, a gas-liquid heat exchanger, a low-grade heat collector, a heat exchanger, and a heat storage medium built into the heat preservation cavity. The heat storage medium is connected to an external power supply device through a heating element. The gas-liquid heat exchanger is installed in the heat preservation cavity and connected to an external liquid supply pipe. The heat energy driven heat pump is installed at the air outlet of the gas-liquid heat exchanger. The low-grade heat collector is installed outside the heat preservation cavity. The heat exchanger is connected to the low-grade heat collector and installed in the heat preservation cavity. The heat preservation cavity is a sealed cavity. The low-temperature air discharged from the gas-liquid heat exchanger passes through the heat energy driven heat pump and then passes through the heat storage medium and the heat exchanger to exchange heat with the fluid in the gas-liquid heat exchanger again. The electric heat storage device with multiple heat sources for heating provided by the embodiment of the present invention realizes the cascade utilization of heat, improves the utilization efficiency of heat, and reduces electricity costs.

Description

Technical Field

[0001] The invention relates to the field of thermal energy technology, and in particular to an electric heat storage device for heating with multiple heat sources. Background Art

[0002] With the rapid development of the power industry, more and more power station systems have emerged in China. The load is reduced during the off-peak period, resulting in a large amount of surplus off-peak electricity. The characteristics of power products are that production, supply and sales are completed at the same time. The large amount of surplus off-peak electricity leads to the waste of power resources, which is not conducive to energy conservation and environmental protection. For this reason, different electricity prices are used for off-peak electricity and peak electricity to urge people to use electricity at off-peak times, improve energy utilization and reduce waste.

[0003] Hot water or hot oil is often used in cold winter and industrial production. Traditionally, electric heating is used to provide hot water and hot oil. At present, some electric heat storage devices have also appeared. They convert cheap off-peak electricity into heat energy through heating elements and store it in the heat storage medium; in the peak electricity stage with the highest price, the heat of the heat storage medium is transferred to water, thermal oil and other media through air and other media, so as to supply hot water or hot oil to users and industrial producers, thereby reducing electricity costs. However, the existing electric heat storage devices have low heat storage efficiency and the electricity consumption is still high. Summary of the invention

[0004] The embodiment of the present invention provides an electric heat storage device for heating with multiple heat sources, which is used to solve the defect of high electricity cost of domestic and industrial hot water and hot oil in the prior art, realize peak-shifting electricity consumption, and improve heat storage efficiency.

[0005] An embodiment of the present invention provides an electric heat storage device for heating with multiple heat sources, comprising a heat preservation cavity, a heat energy driven heat pump, a gas-liquid heat exchanger, a low-grade heat collector, a heat exchanger and a heat storage medium built into the heat preservation cavity, wherein the heat storage medium is connected to an external power supply device through a heating element, the gas-liquid heat exchanger is installed in the heat preservation cavity and communicated with an external liquid supply pipe, the heat energy driven heat pump is installed at the air outlet of the gas-liquid heat exchanger, the low-grade heat collector is installed outside the heat preservation cavity, the heat exchanger is connected to the low-grade heat collector and installed in the heat preservation cavity, the heat preservation cavity is a sealed cavity, and the low-temperature air discharged from the gas-liquid heat exchanger passes through the heat energy driven heat pump and then passes through the heat storage medium and the heat exchanger to exchange heat with the fluid in the gas-liquid heat exchanger again.

[0006] According to an electric heat storage device with multiple heat sources for heating according to one embodiment of the present invention, one end of the heating element is installed inside the heat storage medium, and the other end of the heating element extends out of the heat preservation cavity.

[0007] According to an electric heat storage device with multiple heat sources for heating according to an embodiment of the present invention, there are multiple heating elements.

[0008] According to an electric heat storage device with multiple heat sources for heating according to one embodiment of the present invention, the heat preservation cavity includes an outer wall and an inner wall, the outer wall is located outside the inner wall, and the accommodating space formed by connecting the inner wall and the outer wall is filled with heat preservation material.

[0009] According to the electric heat storage device with multiple heat sources for heating according to one embodiment of the present invention, the heat storage medium is any one of magnesium bricks, steel balls, molten salt and paraffin.

[0010] According to an electric heat storage device with multiple heat sources for heating according to one embodiment of the present invention, the thermal energy driven heat pump is a Villemire heat pump, wherein the medium temperature chamber and the high temperature chamber of the Villemire heat pump are located in the insulation chamber, the room temperature chamber of the Villemire is located outside the insulation chamber, and the medium temperature chamber of the Villemire heat pump is located at the air outlet of the gas-liquid heat exchanger.

[0011] The electric heat storage device for heating with multiple heat sources according to one embodiment of the present invention further includes a circulation fan, and the thermal energy driven heat pump is located between the impeller of the circulation fan and the air outlet of the gas-liquid heat exchanger.

[0012] According to an electric heat storage device with multiple heat sources for heating according to one embodiment of the present invention, the circulating fan includes an impeller, a rotating shaft and a driving member, the driving member is located outside the thermal insulation cavity, the impeller is a high-temperature impeller arranged in the thermal insulation cavity, and the high-temperature impeller is connected to the driving member through the rotating shaft.

[0013] According to an electric heat storage device with multiple heat sources for heating according to one embodiment of the present invention, when the heat source temperature is higher than the required heat flow temperature, the heat exchanger is installed on the air outlet side of the heat storage medium, and when the heat source temperature is lower than the required heat flow temperature, the heat exchanger is installed on the air inlet side of the heat storage medium.

[0014] An electric heat storage device with multiple heat sources for heating is provided in an embodiment of the present invention. A thermal energy driven heat pump and a low-grade heat collector are introduced into the electric heat storage device. Heat is absorbed from a low-temperature heat source and heat is released at a high-temperature heat source at a heat level that is several times the energy consumption, thereby reducing the power consumption of the electric heat storage device and lowering the electricity cost. At the same time, the low-temperature air coming out of the gas-liquid heat exchanger enters the thermal energy driven heat pump for preheating, and then enters the heat storage medium and heat exchanger with a higher temperature, thereby realizing the step-by-step utilization of heat, improving the utilization efficiency of heat, and further reducing the power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic structural diagram of an electric heat storage device for heating with multiple heat sources provided in an embodiment of the present invention;

[0017] Figure 2 It is a schematic structural diagram of an electric heat storage device for supplying heat from multiple heat sources provided in another embodiment of the present invention.

[0018] Reference numerals:

[0019] 10. Insulation cavity; 11. Outer wall; 12. Inner wall; 13. Insulation material; 20. Thermal energy driven heat pump; 21. Room temperature cavity; 22. Medium temperature cavity; 23. High temperature cavity; 30. Gas-liquid heat exchanger; 31. Liquid flow channel; 40. Low-grade heat collector; 50. Heat exchanger; 60. Heat storage medium; 70. Heating element; 80. Circulation fan; 81. Impeller; 82. Rotating shaft; 83. Driving part. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "first" and "second" are for the purpose of clearly describing the numbering of product components and do not represent any substantial difference. The directions of "up", "down", "left" and "right" are all based on the directions shown in the accompanying drawings. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0022] Combine the following Figure 1 and Figure 2 The structure of the electric heat storage device for heating with multiple heat sources according to an embodiment of the present invention is described. The object to be heated may be any desired fluid such as liquid or gas, and the embodiment of the present invention does not specifically limit it. For example, the fluid may be domestic water or industrial oil. For the convenience of description, the following description is made by taking hot water as an example.

[0023] like Figure 1 As shown, the electric heat storage device with multiple heat sources for heating provided by the embodiment of the present invention includes a heat preservation cavity 10, a heat energy driven heat pump 20, a gas-liquid heat exchanger 30, a low-grade heat collector 40, a heat exchanger 50 and a heat storage medium 60. The heat storage medium 60 is built into the heat preservation cavity 10, and the heat storage medium 60 is connected to an external power supply device through a heating element 70. The external power supply device is electrically connected to the heating element 70, and the heat storage medium 60 is heated by the heating element 70 to store heat in the heat storage medium 60. The heat energy driven heat pump 20 is installed at the air outlet of the gas-liquid heat exchanger 30. The low-grade heat collector 40 is located outside the heat preservation cavity 10, and the heat exchanger 50 is located in the heat preservation cavity 10 and is connected to the low-grade heat collector 40. The gas-liquid heat exchanger 30 is installed in the heat preservation cavity 10 and is connected to the external liquid supply pipe. The heat preservation cavity 10 is a sealed cavity. The low-temperature air discharged from the gas-liquid heat exchanger 30 passes through the heat energy driven heat pump 20 and then passes through the heat storage medium 60 and the heat exchanger 50 to exchange heat with the fluid in the gas-liquid heat exchanger 30 again. Figure 1 As shown, the gas-liquid heat exchanger 30 includes a liquid flow channel 31 , and both ends of the liquid flow channel 31 extend out of the heat preservation cavity 10 .

[0024] It should be noted that the order in which the circulating air passes through the heat exchanger 50 and the heat storage medium 60 is not specifically limited. Depending on the required fluid temperature and the heat source temperature, the circulating air may first pass through the heat exchanger 50 and then pass through the heat storage medium 60, or the air may first pass through the heat storage medium 60 and then pass through the heat exchanger 50. The low-grade heat collector 40 absorbs low-grade heat such as external solar energy or waste heat, and transfers the heat to the circulating air in the heat preservation cavity 10 through the heat exchanger 50.

[0025] When in use, in the off-peak electricity stage, the heat-driven heat pump 20 and the low-grade heat collector 40 are in operation, and the heating element 70 continuously heats the heat storage medium 60, converting the electrical energy into heat energy and storing it in the heat storage medium 60. At the same time, the air discharged from the gas-liquid heat exchanger 30 is initially heated by the heat-driven heat pump 20, and then heat-exchanged with the heat storage medium 60 through the heat exchanger 50 to form high-temperature air, and the high-temperature air exchanges heat with the low-temperature water in the gas-liquid heat exchanger 30, thereby providing the required hot water for the user. The air in the gas-liquid heat exchanger 30 that has released heat is preheated again by the heat-driven heat pump 20, and then heat-exchanged with the heat storage medium 60 through the heat exchanger 50, and hot water is provided in a reciprocating cycle. During the peak electricity stage, the heating element 70 stops heating, the thermal energy driven heat pump 20 and the low-grade heat collector 40 continue to operate, and the low-temperature air coming out of the gas-liquid heat exchanger 30 enters the thermal energy driven heat pump 20 for preheating, and further enters the heat exchanger 50 and the heat storage medium 60 to absorb heat to form high-temperature air. The high-temperature air exchanges heat with the fluid inside the gas-liquid heat exchanger 30 in the gas-liquid heat exchanger 30, and the temperature is reduced, and the cycle is repeated in sequence.

[0026] The electric heat storage device with multiple heat sources for heating provided in the embodiment of the present invention converts cheap off-peak electricity into thermal energy through the heating element 70 and stores it in the heat storage medium 60. The thermal energy driven heat pump 20 uses thermal energy as the driving force, which further reduces the energy consumption compared with the vapor compression heat pump driven by electrical energy. During the peak electricity stage with the highest price, the air in the insulation cavity 10 circulates, and the low-temperature fluid on the user side is heated by the air in the gas-liquid heat exchanger 30. At the same time, the low-grade heat collector 40 absorbs solar energy or industrial waste heat, and transfers the heat to the circulating air in the insulation cavity 10 through the heat exchanger 50, further reducing the energy consumption. The electric heat storage device with multiple heat sources for heating introduces a heat-driven heat pump 20 and a low-grade heat collector 40 into the electric heat storage device, absorbs heat from the low-temperature heat source and releases heat several times the energy consumption at the high-temperature heat source, thereby reducing the power consumption of the electric heat storage device and lowering the electricity cost; at the same time, the low-temperature air coming out of the gas-liquid heat exchanger 30 enters the heat-driven heat pump 20 for preheating, and then enters the heat storage medium 60 and the heat exchanger 50 with a higher temperature, thereby realizing the step-by-step utilization of heat, improving the utilization efficiency of heat, and helping to further reduce the power consumption.

[0027] Specifically, the heat-driven heat pump 20 is a Villemire heat pump, which includes a room temperature chamber 21, a medium temperature chamber 22 and a high temperature chamber 23. The room temperature chamber 21 is located outside the heat-insulating chamber 10, and the medium temperature chamber 22 and the high temperature chamber 23 are located inside the heat-insulating chamber 10, and the medium temperature chamber 22 is arranged corresponding to the air outlet of the gas-liquid heat exchanger 30. The low-temperature air coming out of the gas-liquid heat exchanger 30 enters the medium temperature chamber 22 of the heat-driven heat pump 20 for preheating, and then enters the heat storage medium 60 and the high temperature chamber 23 with a higher temperature to absorb heat to form high-temperature air. The high-temperature air exchanges heat with the fluid in the gas-liquid heat exchanger 30 to release heat, and the fluid absorbs heat to supply the heat to the user. Among them, the heat storage medium 60 and the high temperature chamber 23 can be thermally connected, and there is no specific limitation on this.

[0028] One end of the heating element 70 is installed inside the heat storage medium 60, and the other end of the heating element 70 extends out of the heat preservation cavity 10. Figure 1 As shown, the heating element 70 penetrates the entire heat storage medium 60 in the transverse direction, and extends through the heat preservation cavity 10 to the outside of the heat preservation cavity 10 so as to be connected to the electrical lead of the external power supply device.

[0029] Based on any of the above embodiments, there can be multiple heating elements 70. Multiple heating elements 70 are arranged in parallel to facilitate connection with the electrical leads of the external power supply device. Of course, multiple heating elements 70 can be arranged in different directions, such as some heating elements 70 are arranged in the horizontal direction and other heating elements 70 are arranged in the longitudinal direction. With the help of multiple heating elements 70, the heat storage medium 60 is heated at the same time, so that the heat storage medium 60 can quickly accumulate a large amount of heat and heat up quickly.

[0030] The heat preservation cavity 10 includes an outer wall 11 and an inner wall 12. The outer wall 11 is located outside the inner wall 12. The accommodation space formed between the inner wall 12 and the outer wall 11 is filled with heat preservation material 13. Figure 1 As shown, the inner wall 12 and the outer wall 11 are connected to each other and form a certain accommodation space between the two. The accommodation space is filled with a heat-insulating material 13 to prevent heat from diffusing outward and improve the utilization rate of heat energy. The heat-insulating material 13 can be any one or a combination of multiple types of polyester foam, glass wool and rock wool, which is not specifically limited in the embodiment of the present invention.

[0031] In an embodiment of the present invention, the heat storage medium 60 uses solid heat storage materials such as magnesium bricks and steel balls or phase change heat storage materials such as molten salt and paraffin, and has a high heat storage density. For example, the heat storage medium 60 is formed by stacking a plurality of magnesium bricks or steel blocks. For another example, the heat storage medium 60 uses high-temperature molten salt, and the high-temperature molten salt is stored in a shell-like structure. Of course, the heat storage medium 60 can also use thermochemical heat storage materials or adsorption heat storage materials.

[0032] Based on any of the above embodiments, the electric heat storage device for multi-heat source heating provided in the embodiment of the present invention further includes a circulating fan 80, and the heat energy driven heat pump 20 is installed between the impeller of the circulating fan 80 and the air outlet of the gas-liquid heat exchanger 30. Figure 1 As shown, the low-temperature air discharged from the air outlet of the gas-liquid heat exchanger 30 is preheated by the medium-temperature chamber 22 of the heat-driven heat pump 20, such as the Villemire heat pump, and then flows in the reverse direction under the action of the circulating fan 80, and exchanges heat with the heat storage medium 60 to form high-temperature air. With the help of the circulating fan 80, the air flow direction in the heat preservation cavity 10 can be effectively controlled to prevent the air flowing through the medium-temperature chamber 22 from directly flowing back to the gas-liquid heat exchanger 30 for heat exchange and reducing the heat utilization rate.

[0033] Specifically, Figure 1 As shown, the circulating fan 80 includes an impeller 81, a rotating shaft 82 and a driving member 83. The impeller 81 is arranged in the heat preservation cavity 10. In order to adapt to the high temperature air in the heat preservation cavity 10, the impeller 81 is made of high temperature resistant material. The driving member 83 can be a rotating motor or other rotating driving member. The driving member 83 is located outside the heat preservation cavity 10, and its driving end is connected to the impeller 81 through the rotating shaft 82. The rotating shaft 82 is rotatably mounted on the wall of the heat preservation cavity 10, and is sealed at the connection to prevent air from escaping.

[0034] Among them, Figure 1 As shown, when the heat source temperature is higher than the required heat flow temperature, the heat exchanger 50 is installed on the air outlet side of the heat storage medium 60. When the heat source temperature is lower than the required heat flow temperature, as shown in Figure 2 As shown, the heat exchanger 50 is installed on the air inlet side of the heat storage medium 60. Figure 1As shown, when the temperature of the heat source is higher than the required heat flow temperature, the heat exchanger 50 is installed on the left side. In the off-peak power stage, during the off-peak power period, the electric energy is converted into heat energy and stored in the heat storage medium 60 through the heating element 70 and the heat energy driven heat pump 20, and the circulating fan 80 is continuously operated. The circulating air circulates counterclockwise inside the heat preservation cavity 10 to play a role in heat transfer; at the same time, low-grade heat such as solar energy and industrial waste heat collected by the low-grade heat collector 40 also exists in the heat storage medium 60. In the peak power stage, the heating element 70 stops working, and the heat energy driven heat pump 20 and the low-grade heat collector 40 keep running continuously; the low-temperature air coming out of the gas-liquid heat exchanger 30 enters the heat energy driven heat pump 20 for preheating, and further enters the heat storage medium 60 through the impeller 81 of the circulating fan 80, and then enters the heat exchanger 50. The high-temperature air coming out of the heat exchanger 50 is cooled down after heat exchange with the fluid inside the gas-liquid heat exchanger 30, and circulates in sequence. The low-temperature fluid enters from the fluid inlet of the liquid flow channel 31, is heated by the high-temperature air passing through the gas-liquid heat exchanger 30, and then is discharged from the fluid outlet to be supplied to the user. Figure 2 As shown, when the heat source temperature is lower than the required heat flow temperature, the heat exchanger 50 is installed on the right side, and its operation process in the valley power and peak power stages is similar to the above and will not be repeated.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electric heat storage device with multiple heat sources for heating, characterized in that: It includes a heat preservation cavity, a heat energy driven heat pump, a gas-liquid heat exchanger, a low-grade heat collector, a heat exchanger and a heat storage medium built into the heat preservation cavity, the heat storage medium is connected to an external power supply device through a heating element, the gas-liquid heat exchanger is installed in the heat preservation cavity and communicated with an external liquid supply pipe, the heat energy driven heat pump is installed at the air outlet of the gas-liquid heat exchanger, the low-grade heat collector is installed outside the heat preservation cavity, the heat exchanger is connected to the low-grade heat collector and installed in the heat preservation cavity, the heat preservation cavity is a sealed cavity, and the low-temperature air discharged from the gas-liquid heat exchanger passes through the heat energy driven heat pump and then passes through the heat storage medium and the heat exchanger to exchange heat with the fluid in the gas-liquid heat exchanger again; The thermal energy driven heat pump is a Villemire heat pump, wherein the medium temperature chamber and the high temperature chamber of the Villemire heat pump are located in the insulation chamber, the room temperature chamber of the Villemire heat pump is located outside the insulation chamber, the medium temperature chamber of the Villemire heat pump is located at the air outlet of the gas-liquid heat exchanger; the heat storage medium is thermally connected to the high temperature chamber.

2. The electric heat storage device with multiple heat sources for heating according to claim 1, characterized in that: One end of the heating element is installed inside the heat storage medium, and the other end of the heating element extends out of the heat preservation cavity.

3. The electric heat storage device with multiple heat sources for heating according to claim 2, characterized in that: The number of the heating elements is multiple.

4. The electric heat storage device with multiple heat sources for heating according to claim 1, characterized in that: The heat-insulating cavity comprises an outer wall and an inner wall, wherein the outer wall is located outside the inner wall, and a receiving space formed by connecting the inner wall and the outer wall is filled with heat-insulating material.

5. The electric heat storage device with multiple heat sources for heating according to claim 1, characterized in that: The heat storage medium is any one of magnesium bricks, steel balls, molten salt and paraffin.

6. The electric heat storage device for multi-heat source heating according to any one of claims 1 to 5, characterized in that: It also includes a circulation fan, and the heat energy driven heat pump is located between the impeller of the circulation fan and the air outlet of the gas-liquid heat exchanger.

7. The electric heat storage device with multiple heat sources for heating according to claim 6, characterized in that: The circulating fan includes an impeller, a rotating shaft and a driving member, wherein the driving member is located outside the heat preservation cavity, and the impeller is a high-temperature impeller arranged in the heat preservation cavity, and the high-temperature impeller is connected to the driving member through the rotating shaft.

8. The electric heat storage device with multiple heat sources for heating according to any one of claims 1 to 5, characterized in that: When the heat source temperature is higher than the required heat flow temperature, the heat exchanger is installed on the air outlet side of the heat storage medium. When the heat source temperature is lower than the required heat flow temperature, the heat exchanger is installed on the air inlet side of the heat storage medium.

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