A heating system and method based on coupled phase change

Abstract

The present invention discloses a heating system and method based on coupled phase change, belonging to the field of civil heating, which includes a civil heating system and a solar heating system. It includes a first water circulation loop composed of a heat source, a heat substation and heat users connected in sequence. The heat storage device includes a box body, and a partition plate is arranged in the middle of the box body. The partition plate divides the interior of the box body into two areas, namely a first heat preservation area and a second heat preservation area. Both the first heat preservation area and the second heat preservation area are provided with an inlet end and an outlet end; both ends of the first heat preservation area are respectively connected to the heat substation and the heat source, and both ends of the second heat preservation area are respectively connected to the heat substation and the heat source; the first heat preservation area, the heater and the second heat preservation area together form a second water circulation loop. By maintaining a relatively high temperature in the second heat preservation area through the second water circulation loop, it is ensured that the water entering the heat substation is within a relatively high temperature range. Combining the phase change heat storage and the solar heating system can suppress the intermittent and unstable characteristics of solar energy, enable the phase change material to reach the phase change region faster, and reduce energy consumption.

Description

Technical Field

[0001] The present invention belongs to the field of civil heating, and relates to a heating system and method based on coupled phase change. Background Art

[0002] Currently, most residential heating adopts the all-day direct supply method. However, for the vast majority of heat users, they do not stay at home all day long. The uninterrupted heating when there is no one will inevitably cause waste of energy. Therefore, the heat metering operation method is the development trend of heating. Heat metering is a heating operation method that measures and charges according to the actual heat consumed by users. Heat users can adjust the heat supply according to their own needs, and charge for the actual heat consumption of heat users, which reduces the heat consumption cost of users and at the same time reduces the system energy consumption. However, the heat metering method will bring problems to the operation of the heat network. Frequent opening and closing of valves by multiple heat users will affect the stability of the heat network; and the lag of the heat network makes the heat source side unable to respond in time to the load changes brought by the opening and closing of valves on the user side, ultimately reducing the user experience.

[0003] At the same time, the use of renewable energy (solar energy, geothermal energy, wind energy, etc.) can further reduce energy consumption. However, due to the intermittency and instability of renewable energy, its direct combination with the heat network will exacerbate the fluctuations of the heat network and have a significant impact on its stable operation. Summary of the Invention

[0004] The purpose of the present invention is to overcome the disadvantages that the existing heating system combined with renewable energy heating and the heat metering method in the above-mentioned prior art will both affect the stability of the heat network, and provide a heating system and method based on coupled phase change.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A heating system based on coupled phase change includes a first water circulation loop composed of a heat source, a heat substation, and heat users connected in sequence. A heat storage device is connected to the inlet pipeline of each heat substation. The heat storage device is connected to a heater, and the outlet end of the heat substation is connected to the heat user; the heat storage device includes a box body, a partition plate is arranged in the middle of the box body, and the partition plate divides the inside of the box body into two areas, namely a first heat preservation area and a second heat preservation area. Both the first heat preservation area and the second heat preservation area are provided with an inlet end and an outlet end; both ends of the first heat preservation area are respectively connected to the heat substation and the heat source, and both ends of the second heat preservation area are respectively connected to the heat substation and the heat source;

[0007] The first heat preservation area, the heater, and the second heat preservation area are respectively connected in sequence through pipelines, and the second heat preservation area is connected to the first heat preservation area through a pipeline. The first heat preservation area, the heater, and the second heat preservation area together form a second water circulation loop.

[0008] Preferably, the first heat preservation area is filled with a low-temperature phase change material; the second heat preservation area is filled with a high-temperature phase change material.

[0009] More preferably, the low-temperature phase change material is fatty acid or paraffin; the high-temperature phase change material is an inorganic salt aqueous solution.

[0010] Preferably, valves are provided on the pipelines connecting the heat source, the heater, the heat station, the heat user, the first heat preservation area and the second heat preservation area.

[0011] Preferably, the inlet end of the second heat preservation area is connected to the outlet end of the heat source, and the outlet end of the second heat preservation area is connected to the inlet end of the heat station; the inlet end of the first heat preservation area is connected to the outlet end of the heat station, and the outlet end of the first heat preservation area is connected to the inlet end of the heat source.

[0012] Preferably, the heater is installed above the heat storage device.

[0013] Preferably, in the heat storage device, the first heat preservation area is located at the top of the second heat preservation area.

[0014] Preferably, in the water circulation loop, the outlet end of the first heat preservation area is connected to the inlet end of the heater, and the outlet end of the heater is connected to the inlet end of the second heat preservation area.

[0015] Preferably, the heater is a solar heater.

[0016] A heating method based on the above heating system includes:

[0017] The first water circulation loop starts to work, the valve at the outlet end of the heat source is opened, the hot water in the heat source flows into the second heat preservation area, and flows into the heat station through the pipeline in the second heat preservation area, and then flows to the heat user through the heat station to supply heat to the heat user; the water flowing out from the outlet end of the heat user flows through the heat station to the first heat preservation area, and the first heat preservation area returns the water to the heat source for continuous heating;

[0018] When the water flowing out from the outlet end of the heat user flows through the heat station to the first heat preservation area, the temperature of the first heat preservation area decreases, and the second water circulation loop starts to work. The temperature of the water in the second water circulation loop in the pipeline connecting the first heat preservation area and the heater decreases. The cooled water enters the heater for heating, and the heated heat flows into the pipeline of the second heat preservation area, so that the temperature of the second heat preservation area increases, and the water in the first water circulation loop flowing through the second heat preservation area enters the heat station at a relatively high temperature.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention discloses a heating system based on coupled phase change, which includes a first water circulation loop composed of a heat source, a heat substation, and heat users connected in sequence. The heat storage device includes a box body, and a partition plate is provided in the middle of the box body. The partition plate divides the inside of the box body into two areas, namely a first heat preservation area and a second heat preservation area. Both the first heat preservation area and the second heat preservation area are provided with an inlet end and an outlet end; both ends of the first heat preservation area are connected to the heat substation and the heat source respectively, and both ends of the second heat preservation area are connected to the heat substation and the heat source respectively; the first heat preservation area, the heater, and the second heat preservation area together form a second water circulation loop. By maintaining a relatively high temperature in the second heat preservation area through the second water circulation loop, the water entering the heat substation is ensured to be within a relatively high temperature range. When the heat source provides surplus heat, when the working medium carrying the excess heat flows through the heat storage device, this part of the heat will be stored in the first heat preservation area and the second heat preservation area, rather than directly entering the heat substation; moreover, due to the constant temperature property of the phase change process, even if this part of the heat is lost in the water supply pipeline, it will not significantly affect the temperature on the heat user side. When the heat load required by the heat network increases, for example, when a certain heat user suddenly opens their own heating valve and the heat in the heat network is no longer sufficient to support the current heat load. At this time, the heat in the first heat preservation area and the second heat preservation area is released to maintain the temperature of the heat network and eliminate the heat network fluctuations. That is, in the present invention, a double-layer heat storage material is set to match the water supply pipeline and the return water pipeline, which can realize the cascaded utilization of energy. At the same time, the system of the present invention can suppress the load fluctuations of the heat network, thereby solving the problem that the existing heating system combined with renewable energy heating or heat metering methods affects the stability of the heat network.

[0021] Furthermore, phase change heat storage is a technology for heat storage based on the latent heat of phase change of materials. Since the temperature of the material is nearly constant during the phase change process, it is easy to control the temperature; at the same time, due to the generally high latent heat of phase change of the heat storage material, the heat storage density of phase change heat storage is large, which has great advantages. Adopting a composite system of low-temperature phase change materials and high-temperature phase change materials can match the water supply pipeline and the return water pipeline with different temperatures, enabling both pipelines to be in the phase change zone simultaneously. While ensuring temperature stability, it realizes the cascaded utilization of energy.

[0022] Furthermore, valves are provided on the pipelines connecting the heat source, the heater, the heat substation, the heat users, the first heat preservation area, and the second heat preservation area, making the entire system easy to control and more practical.

[0023] Furthermore, the heater is installed above the heat storage device. In the heat storage device, the first heat preservation area is located at the top of the second heat preservation area, and the heated hot water enters the heater from bottom to top. The reason for choosing this flow direction is that the bottom-up heating method can cause natural convection due to the density difference during the phase change process of the heat storage material, strengthening heat transfer; at the same time, since two phase change materials are placed in the storage tank and their phase change temperatures decrease along the flow direction, according to the characteristics of the series arrangement of phase change materials, heat transfer can be further strengthened.

[0024] Furthermore, a solar heater is adopted as the heater to utilize the surplus solar energy for heating, thereby reducing the energy consumption of the system.

[0025] The present invention also discloses a heating method. The hot water from the heat source first flows through the heat storage device, then passes through the heat station, and finally reaches the heat user to achieve heating; while the return water from the heat user side first flows through the heat station, and then passes through the heat storage device and flows back to the heat source. In the heat storage device, the water supply pipe flows through the second heat preservation area, and the return water pipe flows through the first heat preservation area. The water in the second water circulation loop is heated in the heater to form hot water at a suitable temperature, and then successively flows through the second heat preservation area and the first heat preservation area, and finally flows back to the solar heater. Using the characteristics of the heat storage device to suppress the intermittency and instability of solar energy can reduce the energy consumption on the heat source side, and at the same time enable the phase change material to reach the phase change area faster, effectively improving the heat exchange efficiency. Description of the Drawings

[0026] Figure 1 is a schematic flow chart of the heating system of the present invention;

[0027] Figure 2 is a schematic structural diagram of the heat storage device in the heating system of the present invention.

[0028] Wherein: 1 - heat source; 2 - heat storage device; 21 - box body; 22 - partition board; 3 - heater; 4 - heat station; 5 - heat user; 6 - first heat preservation area; 7 - second heat preservation area. Detailed Embodiments

[0029] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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 of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] The present invention will be further described in detail below with reference to the accompanying drawings:

[0032] Embodiment 1

[0033] A heating system based on coupled phase change, as Figure 1 shown, includes a first water circulation loop composed of a heat source 1, a heat substation 4 and a heat user 5 connected in sequence. A heat storage device 2 is connected to the inlet pipeline of each heat substation 4. The heat storage device 2 is connected to a heater 3. The outlet end of the heat substation 4 is connected to the heat user 5; as Figure 2 shown, the heat storage device 2 includes a box body 21. A partition plate 22 is provided in the middle of the box body 21. The partition plate 22 divides the interior of the box body 21 into two zones, namely a first heat preservation zone 6 and a second heat preservation zone 7. Both the first heat preservation zone 6 and the second heat preservation zone 7 are provided with an inlet end and an outlet end; both ends of the first heat preservation zone 6 are respectively connected to the heat substation 4 and the heat source 1. Both ends of the second heat preservation zone 7 are respectively connected to the heat substation 4 and the heat source 1; the first heat preservation zone 6, the heater 3 and the second heat preservation zone 7 are respectively connected in sequence through pipelines. A pipeline is connected between the second heat preservation zone 7 and the first heat preservation zone 6. The first heat preservation zone 6, the heater 3 and the second heat preservation zone 7 together form a second water circulation loop. The first heat preservation zone 6 is filled with a low-temperature phase change material; the second heat preservation zone 7 is filled with a high-temperature phase change material. The low-temperature phase change material is fatty acid; the high-temperature phase change material is an inorganic salt aqueous solution.

[0034] Embodiment 2

[0035] Except for the following content, the rest are the same as those in Embodiment 1.

[0036] The inlet end of the second heat preservation zone 7 is connected to the outlet end of the heat source 1, and the outlet end of the second heat preservation zone 7 is connected to the inlet end of the heat power station 4; the inlet end of the first heat preservation zone 6 is connected to the outlet end of the heat power station 4, and the outlet end of the first heat preservation zone 6 is connected to the inlet end of the heat source 1. Valves are provided on the pipelines connecting the heat source 1, the heater 3, the heat power station 4, the heat user 5, the first heat preservation zone 6 and the second heat preservation zone 7. The low-temperature phase change material is paraffin wax; the high-temperature phase change material is an inorganic salt aqueous solution.

[0037] Example 3

[0038] Except for the following content, the rest are the same as those in Example 1.

[0039] The heater 3 is installed above the heat storage device 2. In the heat storage device 2, the first heat preservation zone 6 is located at the top of the second heat preservation zone 7. In the water circulation loop, the outlet end of the first heat preservation zone 6 is connected to the inlet end of the heater 3, and the outlet end of the heater 3 is connected to the inlet end of the second heat preservation zone 7. The heater 3 is a solar heater.

[0040] A heating method based on the above heating system is specifically as follows:

[0041] The first water circulation loop starts to work, the valve at the outlet end of the heat source 1 is opened, the hot water in the heat source 1 flows into the second heat preservation zone 7, and flows through the pipeline in the second heat preservation zone 7 into the heat power station 4, and then flows to the heat user 5 through the heat power station 4 to supply heat to the heat user 5; the water flowing out from the outlet end of the heat user 5 flows through the heat power station 4 to the first heat preservation zone 6, and the first heat preservation zone 6 returns the water to the heat source 1 for continuous heating;

[0042] When the water flowing out from the outlet end of the heat user 5 flows through the heat power station 4 to the first heat preservation zone 6, the temperature of the first heat preservation zone 6 decreases, and the second water circulation loop starts to work. The temperature of the water in the second water circulation loop in the pipeline connecting the first heat preservation zone 6 and the heater 3 decreases, and the cooled water enters the heater 3 for heating. The heated heat flows into the pipeline of the second heat preservation zone 7, so that the temperature of the second heat preservation zone 7 increases, and the water in the first water circulation loop flowing through the second heat preservation zone 7 enters the heat power station 4 while maintaining a relatively high temperature.

[0043] The working principle of the system of the present invention is as follows:

[0044] When the heat source provides surplus heat, when the working medium carrying the excess heat flows through the heat storage device, this part of the heat will be stored in the first heat insulation zone and the second heat insulation zone, rather than directly entering the heat station; and due to the constant temperature of the phase change process, even if this part of the heat is lost in the water supply pipeline, it will not significantly affect the temperature on the heat user side. When the heat load required by the heat network increases, for example, when a certain heat user suddenly opens their own heating valve, the heat in the heat network is no longer sufficient to support the current heat load. At this time, the heat in the first heat insulation zone and the second heat insulation zone is released to maintain the heat network temperature and eliminate the heat network fluctuations.

[0045] In summary, by using the system of the present invention, the heat storage device in the system is used to absorb the surplus heat of the heat network or supplement sufficient heat to the heat network. Moreover, due to the characteristic of constant temperature during the phase change process, the change of the heat in the heat network will not cause obvious fluctuations in the temperature on the heat user side. At the same time, combining the phase change heat storage with the solar heating system can smooth out the intermittent and unstable characteristics of solar energy, enable the phase change material to reach the phase change zone faster, and reduce energy consumption. Two heat storage materials are placed in the heat storage device, which can realize the cascade utilization of energy.

[0046] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention fall within the protection scope of the claims of the present invention.

Claims

1. A heating system based on coupled phase change, characterized in that, it includes a first water circulation loop composed of a heat source (1), a heat substation (4) and a heat user (5) connected in sequence. A heat storage device (2) is connected to the inlet pipeline of each heat substation (4). The heat storage device (2) is connected to a heater (3). The outlet end of the heat substation (4) is connected to the heat user (5); the heat storage device (2) includes a box body (21). A partition plate (22) is arranged in the middle of the box body (21). The partition plate (22) divides the interior of the box body (21) into two areas, namely a first heat preservation area (6) and a second heat preservation area (7). Both the first heat preservation area (6) and the second heat preservation area (7) are provided with an inlet end and an outlet end; both ends of the first heat preservation area (6) are respectively connected to the heat substation (4) and the heat source (1). Both ends of the second heat preservation area (7) are respectively connected to the heat substation (4) and the heat source (1); the first heat preservation area (6) is filled with a low-temperature phase change material; the second heat preservation area (7) is filled with a high-temperature phase change material; The first heat preservation area (6), the heater (3) and the second heat preservation area (7) are respectively connected in sequence through pipelines. A pipeline is connected between the second heat preservation area (7) and the first heat preservation area (6). The first heat preservation area (6), the heater (3) and the second heat preservation area (7) together form a second water circulation loop; valves are provided on the pipelines connecting the heat source (1), the heater (3), the heat substation (4), the heat user (5), the first heat preservation area (6) and the second heat preservation area (7).

2. The heating system according to claim 1, characterized in that, the low-temperature phase change material is fatty acid or paraffin; the high-temperature phase change material is an inorganic salt aqueous solution.

3. The heating system according to claim 1, characterized in that, the inlet end of the second heat preservation area (7) is connected to the outlet end of the heat source (1), and the outlet end of the second heat preservation area (7) is connected to the inlet end of the heat substation (4); the inlet end of the first heat preservation area (6) is connected to the outlet end of the heat substation (4), and the outlet end of the first heat preservation area (6) is connected to the inlet end of the heat source (1).

4. The heating system according to claim 1, characterized in that, the heater (3) is installed above the heat storage device (2).

5. The heating system according to claim 1, characterized in that, in the heat storage device (2), the first heat preservation area (6) is located at the top of the second heat preservation area (7).

6. The heating system according to claim 1, characterized in that, in the water circulation loop, the outlet end of the first heat preservation area (6) is connected to the inlet end of the heater (3), and the outlet end of the heater (3) is connected to the inlet end of the second heat preservation area (7).

7. The heating system according to claim 1, characterized in that, the heater (3) is a solar heater.

8. A heating method based on the heating system according to any one of claims 1 to 7, characterized in that, it includes: The first water circulation loop starts to work. The valve at the outlet end of the heat source (1) is opened, and the hot water in the heat source (1) flows into the second heat preservation area (7), and then flows into the heat supply station (4) through the pipeline in the second heat preservation area (7), and then flows to the heat user (5) through the heat supply station (4) to supply heat to the heat user (5); the water flowing out from the outlet end of the heat user (5) flows through the heat supply station (4) to the first heat preservation area (6), and the first heat preservation area (6) returns the water to the heat source (1) for continuous heating; When the water flowing out from the outlet end of the heat user (5) flows through the heat supply station (4) to the first heat preservation area (6), the temperature of the first heat preservation area (6) decreases, and the second water circulation loop starts to work. The temperature of the water in the second water circulation loop in the pipeline connected to the heater (3) in the first heat preservation area (6) decreases, and the cooled water enters the heater (3) for heating. The heated heat flows into the pipeline of the second heat preservation area (7), increasing the temperature of the second heat preservation area (7), so that the water in the first water circulation loop flowing through the second heat preservation area (7) enters the heat supply station (4) at a relatively high temperature.

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