A coupled solar heat storage heating system and a control method thereof

Abstract

A coupled solar heat storage heating system and a control method thereof, comprising a heating system body composed of a solar heat collector, an electrode hot water boiler, a heat storage water tank, a solar heat collector circulating water pump, a water distributor and a water collector, a hot water supply side of the solar heat collector is connected with a high temperature side of a tubular water-water heat exchanger arranged in the heat storage water tank through a heat storage water supply pipeline, a hot water return side of the solar heat collector is connected with a low temperature side of the tubular water-water heat exchanger arranged in the heat storage water tank through a heat storage water return pipeline with the solar heat collector circulating water pump, the heat storage water tank is connected with the water distributor and the water collector through a heating water supply pipeline and a heating water return pipeline respectively, the heating water supply pipeline and the heating water return pipeline are connected with a hot water supply side of the electrode hot water boiler and a hot water return side of the electrode hot water boiler respectively, and an electric switch valve, a circulating water pump and a full-automatic water filter are further arranged on the heating water return pipeline in sequence.

Description

Technical Field

[0001] This invention belongs to the field of integrated energy technology, and relates to a coupled solar thermal storage heating system and its control method, which is particularly suitable for heating systems in areas with abundant solar energy resources and stable heating needs. Background Technology

[0002] With the expansion of residential areas and the improvement of people's living standards, the demand for winter heating is rising daily. Heating is the world's largest end-use energy consumption sector. Data from the International Energy Agency shows that heating accounts for 50% of global end-use energy consumption and 40% of global carbon dioxide emissions. As a high-carbon emission industry, there is still huge room for energy conservation and emission reduction in heating. my country's energy resource endowment of being rich in coal, poor in oil, and lacking in gas dictates that heating in China must be based on the efficient utilization of coal. Currently, heating in northern cities mainly comes from combined heat and power (CHP) and heat produced by various coal-fired and gas-fired boilers. The proportion of coal burning is still relatively high, which generates a large amount of carbon dioxide, easily causing air pollution and resource waste, and is not conducive to building energy-saving and environmentally friendly cities.

[0003] Considering the enormous potential for energy conservation and emission reduction behind the increasing demand for heating and the relevant national "dual carbon" initiatives, this invention utilizes solar energy as a heat source, an electrode hot water boiler as an emergency heat source, and a hot water storage tank as an energy-saving regulating heat source. This improves the utilization rate of renewable energy, ensures the stability and reliability of the heating system, and reduces operating costs and carbon emissions, thus possessing broad application prospects. Therefore, a combined solar thermal storage heating system and its control method are designed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a coupled solar thermal storage heating system and its control method that has high renewable energy utilization, stable and reliable system, and high energy efficiency, in view of the above-mentioned defects of the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a coupled solar thermal storage heating system, comprising a heating system body, wherein the heating system body consists of a solar collector, an electrode hot water boiler, a hot water storage tank, a solar collector circulating water pump, a distributor, and a collector, which are connected by pipes. The hot water supply side of the solar collector is connected to the high-temperature side of a shell-and-tube water-to-water heat exchanger installed in the hot water storage tank through a thermal storage supply pipe, and the hot water return side of the solar collector is connected to the low-temperature side of a shell-and-tube water-to-water heat exchanger installed in the hot water storage tank through a thermal storage return pipe equipped with a solar collector circulating water pump. The hot water storage tank is connected to the distributor and collector through heating supply pipes and heating return pipes, respectively, and the heating supply pipes and heating return pipes are connected to the hot water supply side and the hot water return side of the electrode hot water boiler, respectively. An electric switch valve, a circulating water pump, and a fully automatic water filter are also sequentially installed on the heating return pipe.

[0006] Preferably, the solar collector's heat storage water supply pipe is equipped with an electric three-way regulating valve, which is connected to the high-temperature radiator via a bypass. Temperature sensor A and temperature sensor B are connected to the front and rear sides of the high-temperature radiator respectively to monitor its water temperature.

[0007] Preferably, an automatic constant pressure water supply unit is connected to the heat storage return water pipe of the solar collector between the solar collector circulating water pump and the hot water storage tank, and to the heating return water pipe of the hot water storage tank between the fully automatic water filter and the water collector.

[0008] Preferably, the heating water supply pipe of the hot water storage tank is equipped with an electric switch valve and a temperature sensor C. The temperature sensor C is used to monitor the heating water temperature of the hot water storage tank. The heating return water pipe of the hot water storage tank consists of two parallel pipes. One pipe is equipped with at least one hot water storage tank circulating water pump, and the other pipe is equipped with at least one electrode hot water boiler circulating water pump. Electric switch valves are installed on the pipes before and after the hot water storage tank circulating water pump and the electrode hot water boiler circulating water pump, respectively.

[0009] Preferably, the number of circulating water pumps for the hot water storage tank and the electrode hot water boiler are both two, which are connected in parallel, with one in normal use and the other as a backup.

[0010] A control method for the above-mentioned coupled solar thermal storage heating system is provided. The control method divides the heating system into three heating modes and controls them accordingly. The first heating mode is heating by solar collectors and hot water storage tanks. The second heating mode is heating by electrode hot water boilers. The third heating mode is heating by electrode hot water boilers while using hot water storage tanks for thermal storage.

[0011] Preferably, in the first heating mode, the solar collector, high-temperature radiator, hot water storage tank, solar collector circulating water pump, hot water storage tank circulating water pump, automatic constant pressure water supply unit, and fully automatic water filter operate. Hot water generated by the solar collector using solar energy enters the hot water storage tank via a water-to-water heat exchanger, heats the stored water, and then returns to the solar collector under the action of the solar collector circulating water pump. The hot water in the storage tank is used as heating water and supplied to heating users via a distributor. The heating return water from the users returns to the collector, undergoes water quality treatment by the fully automatic water filter, and then is pumped back to the hot water storage tank. Returning to the hot water storage tank, when solar energy resources cannot be effectively guaranteed and the hot water supply temperature of the hot water storage tank can meet the heating demand, the solar collector, high-temperature radiator, and solar collector circulating water pump will stop operating, while the hot water storage tank, hot water storage tank circulating water pump, automatic constant pressure water supply unit, and fully automatic water filter will operate normally. In the first heating mode, when the water temperature T1 monitored by the temperature sensor before the electric three-way regulating valve on the hot water supply pipeline of the solar collector is greater than or equal to 95℃, the bypass water volume of the high-temperature radiator will be controlled by the electric three-way regulating valve to ensure that the water temperature T2 monitored by the temperature sensor after the electric three-way regulating valve is less than or equal to 85℃ and not lower than 80℃.

[0012] As a preferred option: In the second heating mode, the electrode hot water boiler, the electrode hot water boiler circulating water pump, the automatic constant pressure water supply unit, and the fully automatic water filter are in operation; the heating return water from the heating users returns to the water collector, is treated by the fully automatic water filter, and then returns to the electrode hot water boiler under the action of the electrode hot water boiler circulating water pump. After heat exchange, it is used as heating water and supplied to the heating users through the water distributor.

[0013] As a preferred option: In the third heating mode, the system includes an electrode hot water boiler, a hot water storage tank, an electrode hot water boiler circulating pump, an automatic constant pressure water supply unit, and a fully automatic water filter. After the heating return water from the heating users returns to the water collector, it undergoes water quality treatment by the fully automatic water filter and is then connected in parallel with the return water pipe of the hot water storage tank. Under the action of the electrode hot water boiler circulating pump, the hot water enters the electrode hot water boiler. After heat exchange, the hot water is distributed through the water supply header by the electric regulating valve. Part of the water is used as heating water and supplied to the heating users through the water distributor, while the other part is supplied to the hot water storage tank for heat storage.

[0014] As a preferred option: the first heating mode is used first among the three heating modes; when the solar energy resources of the first heating mode cannot be effectively guaranteed and the water supply temperature T3 of the hot water storage tank is less than 50℃, the second heating mode is switched to; the third heating mode is switched to during off-peak hours such as at night.

[0015] The beneficial technical effects of the present invention are as follows: (1) By using solar energy resources coupled with a hot water storage tank, the present invention can improve the utilization rate of renewable energy and reduce the primary energy consumption of the heating system, thereby reducing the carbon emissions of the heating system; (2) By using an electrode hot water boiler as an emergency heat source, the heating system can be guaranteed to operate stably and reliably while further reducing the consumption of primary energy; (3) By using the hot water storage tank as an energy-saving regulating heat source, the operating cost of the heating system can be effectively reduced, which is conducive to the comprehensive and efficient utilization of energy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the coupled solar thermal storage heating system described in this invention; Figure 2 This is a schematic diagram of the process under the first heating mode; Figure 3 This is a flowchart illustrating the process under the second heating mode. Figure 4 This is a schematic diagram of the process under the third heating mode. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the invention. Figure 1As shown, a coupled solar thermal storage heating system includes a heating system body, which consists of a solar collector 1, an electrode hot water boiler 2, a hot water storage tank 3, a solar collector circulating water pump 4, a water distributor 10, and a water collector 11, all connected by pipes. The hot water supply side of the solar collector 1 is connected to the high-temperature side of a shell-and-tube water-to-water heat exchanger 12 installed in the hot water storage tank 3 via a thermal storage water supply pipe 21. The hot water return side of the solar collector 1 is connected to a pipe... The low-temperature side of the shell-type water-to-water heat exchanger 12 is connected to the heat storage return water pipe 22 with a solar collector circulating water pump 4. The hot water storage tank 3 is connected to the water distributor 10 and the water collector 11 through the heating water supply pipe 23 and the heating water return pipe 24 respectively. The heating water supply pipe 23 and the heating water return pipe 24 are connected to the hot water supply side and the hot water return side of the electrode hot water boiler 2 respectively. An electric switch valve, a circulating water pump and a fully automatic water filter 9 are also installed in sequence on the heating water return pipe 24.

[0020] The solar collector 1 is equipped with an electric three-way regulating valve F7 on its heat storage water supply pipe 21. The electric three-way regulating valve F7 is connected to the high-temperature radiator 7 via a bypass, and temperature sensors A13 and B14 are connected to the front and rear sides of the high-temperature radiator 7 respectively to monitor its water temperature.

[0021] Automatic pressure water supply unit 8 is connected to the heat storage return water pipe 22 of the solar collector 1 between the solar collector circulating water pump 4 and the hot water storage tank 3, and to the heating return water pipe 24 of the hot water storage tank 3 between the fully automatic water filter 9 and the water collector 11.

[0022] The heating water supply pipe 23 of the hot water storage tank 3 is equipped with an electric switch valve and a temperature sensor C15. The temperature sensor C15 is used to monitor the heating water temperature of the hot water storage tank. The heating return water pipe 24 of the hot water storage tank 3 consists of two parallel pipes. One pipe is equipped with at least one hot water storage tank circulating water pump 5, and the other pipe is equipped with at least one electrode hot water boiler circulating water pump 6. Electric switch valves are installed on the pipes before and after the hot water storage tank circulating water pump 5 and the electrode hot water boiler circulating water pump 6, respectively.

[0023] The hot water storage tank circulating water pump 5 and the electrode hot water boiler circulating water pump 6 are both in pairs, arranged in parallel, with one in normal use and the other as a backup.

[0024] Reference Figure 1As shown, an electric switch valve F1 is installed on the hot water supply side of the electrode hot water boiler 2, and an electric switch valve F2 is installed on the heating return water pipe after the circulating water pump 5 of the hot water storage tank. An electric regulating valve F3 is installed on the inlet header of the water distributor 10. Electric switch valves F6 and F4 are respectively installed on the outlet header of the water collector 11 after the fully automatic water filter 9 connected in parallel before the electrode hot water boiler circulating water pump 6 and the return water pipe of the hot water storage tank 3. An electric switch valve F5 is installed on the heating return water pipe connected to the outlet header of the water collector 11 after the fully automatic water filter 9 before the circulating water pump 5 of the hot water storage tank. An electric three-way regulating valve F7 is installed on the heat storage water supply pipe of the solar collector 1 and is connected to the high-temperature radiator 7 in a bypass connection.

[0025] A control method for the above-mentioned coupled solar thermal storage heating system is provided. The control method divides the heating system into three heating modes and controls them accordingly. The first heating mode is heating by solar collectors and hot water storage tanks. The second heating mode is heating by electrode hot water boilers. The third heating mode is heating by electrode hot water boilers while using hot water storage tanks for thermal storage.

[0026] Reference Figure 2 As shown, in the first heating mode, the solar collector, high-temperature radiator, hot water storage tank, solar collector circulating water pump, hot water storage tank circulating water pump, automatic constant pressure water supply unit, and fully automatic water filter are in operation. Hot water generated by the solar collector using solar energy enters the hot water storage tank via a water-to-water heat exchanger, heats the stored water in the tank, and then returns to the solar collector under the action of the solar collector circulating water pump. The hot water in the storage tank is used as heating water and supplied to heating users through a distributor. The heating return water from the users returns to the collector, undergoes water quality treatment by the fully automatic water filter, and then is pumped back to the storage tank by the hot water storage tank circulating water pump. Returning to the hot water storage tank, when solar energy resources cannot be effectively guaranteed and the hot water supply temperature of the hot water storage tank can meet the heating demand, the solar collector, high-temperature radiator, and solar collector circulating water pump will stop operating, while the hot water storage tank, hot water storage tank circulating water pump, automatic constant pressure water supply unit, and fully automatic water filter will operate normally. In the first heating mode, when the water temperature T1 monitored by the temperature sensor before the electric three-way regulating valve on the hot water supply pipeline of the solar collector is greater than or equal to 95℃, the bypass water volume of the high-temperature radiator will be controlled by the electric three-way regulating valve to ensure that the water temperature T2 monitored by the temperature sensor after the electric three-way regulating valve is less than or equal to 85℃ and not lower than 80℃.

[0027] Reference Figure 3As shown, in the second heating mode, the electrode hot water boiler, the electrode hot water boiler circulating water pump, the automatic constant pressure water supply unit, and the fully automatic water filter are in operation. The heating return water from the heating users returns to the water collector, is treated by the fully automatic water filter, and then returns to the electrode hot water boiler under the action of the electrode hot water boiler circulating water pump. After heat exchange, it is used as heating water and supplied to the heating users through the water distributor.

[0028] Reference Figure 4 As shown, in the third heating mode, the system consists of an electrode hot water boiler, a hot water storage tank, an electrode hot water boiler circulating pump, an automatic constant pressure water supply unit, and a fully automatic water filter. The heating return water from the users returns to the water collector and undergoes water quality treatment by the fully automatic water filter before being connected in parallel with the hot water storage tank return water pipe. Under the action of the electrode hot water boiler circulating pump, the hot water enters the electrode hot water boiler. After heat exchange, the hot water is distributed through the water supply header by an electric regulating valve. Part of this water is used as heating water and supplied to the users via a distributor, while the other part is supplied to the hot water storage tank for heat storage.

[0029] The first heating mode is preferred among the three heating modes. When the solar energy resources of the first heating mode cannot be effectively guaranteed and the water supply temperature T3 of the hot water storage tank is less than 50℃, the second heating mode is switched to. The third heating mode is switched to during off-peak hours at night.

[0030] The valve opening status under different heating modes is shown in the table below: The specific embodiments described herein are merely illustrative of the principles and effects of the invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A coupled solar thermal storage heating system, comprising a heating system body, characterized in that: The heating system consists of a solar collector (1), an electrode hot water boiler (2), a hot water storage tank (3), a solar collector circulating water pump (4), a water distributor (10), and a water collector (11), all connected by pipes. The hot water supply side of the solar collector (1) is connected to the high-temperature side of the shell-and-tube water-to-water heat exchanger (12) installed in the hot water storage tank (3) via a heat storage water supply pipe (21). The hot water return side of the solar collector (1) is connected to the low-temperature side of the shell-and-tube water-to-water heat exchanger (12) installed in the hot water storage tank (3) via a water storage supply pipe (21). A heat storage return water pipe (22) with a solar collector circulating water pump (4) is connected. The hot water storage tank (3) is connected to the water distributor (10) and the water collector (11) through the heating water supply pipe (23) and the heating water return pipe (24). The heating water supply pipe (23) and the heating water return pipe (24) are connected to the hot water supply side of the electrode hot water boiler (2) and the hot water return side of the electrode hot water boiler (2) respectively. An electric switch valve, a circulating water pump and a fully automatic water filter (9) are also installed in sequence on the heating water return pipe (24). An electric three-way regulating valve (F7) is installed on the heat storage water supply pipe (21) of the solar collector (1). The electric three-way regulating valve (F7) is connected to the high temperature radiator (7) in a bypass connection. Temperature sensor A (13) and temperature sensor B (14) are connected to the front and rear sides of the high temperature radiator (7) respectively to monitor its water temperature. Furthermore, on the heat storage water supply pipe (21) of the solar collector (1), when the water temperature T1 monitored by the temperature sensor A (13) located in front of the electric three-way regulating valve (F7) is greater than or equal to 95°C, the bypass water volume of the high-temperature radiator (7) is controlled by the electric three-way regulating valve (F7) to ensure that the water temperature T2 monitored by the temperature sensor B (14) located behind the electric three-way regulating valve (F7) is less than or equal to 85°C and not lower than 80°C; the heating water supply pipe (23) of the heat storage tank (3) is equipped with an electric The electric switch valve and temperature sensor C (15) are used to monitor the heating water temperature of the hot water storage tank. The heating return water pipe (24) of the hot water storage tank (3) consists of two parallel pipes. One pipe is equipped with at least one hot water storage tank circulating water pump (5), and the other pipe is equipped with at least one electrode hot water boiler circulating water pump (6). Electric switch valves are installed on the pipes before and after the hot water storage tank circulating water pump (5) and the electrode hot water boiler circulating water pump (6).

2. The coupled solar thermal storage heating system according to claim 1, characterized in that: Automatic pressure water supply unit (8) is connected to the heat storage return water pipe (22) of the solar collector (1) between the solar collector circulating water pump (4) and the hot water storage tank (3), and to the heating return water pipe (24) of the hot water storage tank (3) between the fully automatic water filter (9) and the water collector (11).

3. The coupled solar thermal storage heating system according to claim 2, characterized in that: The number of circulating water pumps (5) for the hot water storage tank and the circulating water pumps (6) for the electrode hot water boiler are both two, and they are arranged in parallel. One is used normally and the other is used as a backup.

4. A control method for a coupled solar thermal storage heating system as described in any one of claims 1 to 3, characterized in that: The control method divides the heating system into three heating modes and controls them accordingly. The first heating mode is heating by solar collectors and hot water storage tanks. The second heating mode is heating by electrode hot water boilers. The third heating mode is heating by electrode hot water boilers while using hot water storage tanks for heat storage.

5. The control method according to claim 4, characterized in that: In the first heating mode, the solar collector, high-temperature radiator, hot water storage tank, solar collector circulating water pump, hot water storage tank circulating water pump, automatic constant pressure water supply unit, and fully automatic water filter are in operation. The hot water generated by the solar collector using solar energy enters the hot water storage tank through the heat storage water supply pipeline and enters the shell-and-tube water-to-water heat exchanger built into the hot water storage tank to heat the stored water. Then, under the action of the solar collector circulating water pump, it returns to the solar collector. The hot water in the hot water storage tank is used as heating water and is supplied to heating users through the water distributor. The heating return water from the heating users returns to the water collector and is treated by the fully automatic water filter before returning to the hot water storage tank under the action of the hot water storage tank circulating water pump. When solar energy resources cannot be effectively guaranteed and the hot water supply temperature of the hot water storage tank can meet the heating demand, the solar collector, high-temperature radiator, and solar collector circulating water pump stop operating, while the hot water storage tank, hot water storage tank circulating water pump, automatic constant pressure water supply unit, and fully automatic water filter operate normally.

6. The control method according to claim 4, characterized in that: In the second heating mode, the electrode hot water boiler, the electrode hot water boiler circulating water pump, the automatic constant pressure water supply unit, and the fully automatic water filter are in operation. The heating return water from the heating users returns to the water collector, is treated by the fully automatic water filter, and then returns to the electrode hot water boiler under the action of the electrode hot water boiler circulating water pump. After heat exchange, it is used as heating water and supplied to the heating users through the water distributor.

7. The control method according to claim 4, characterized in that: In the third heating mode, the electrode hot water boiler, the hot water storage tank, the electrode hot water boiler circulating water pump, the automatic constant pressure water supply unit, and the fully automatic water filter are in operation. The heating return water from the heating users returns to the water collector, is treated by the fully automatic water filter, and is then connected in parallel with the return water pipe of the hot water storage tank. Under the action of the electrode hot water boiler circulating water pump, it enters the electrode hot water boiler. After heat exchange, the hot water is distributed by the electric regulating valve through the water supply header. Part of it is used as heating water and supplied to the heating users through the water distributor, while the other part is supplied to the hot water storage tank for heat storage.

8. The control method according to claim 4, characterized in that: The first heating mode is preferred among the three heating modes; when the solar energy resources of the first heating mode cannot be effectively guaranteed and the water supply temperature T3 of the hot water storage tank is less than 50℃, the second heating mode is switched to; during off-peak hours at night, the third heating mode is switched to.

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