A heating system and its control method based on heat pump to enhance the temperature difference of energy storage

Abstract

A heating system and its control method based on a heat pump to enhance the temperature difference of energy storage, relating to the field of solar thermal energy storage heating technology. Solar collectors are connected to user-side hot water storage tanks to form a user-side decentralized heat collection-storage loop. The user-side hot water storage tanks are connected to hot water supply devices and radiant heat dissipation devices to form a user-side heating loop. The user-side hot water storage tanks are connected to the heating network to form a user-network loop. The auxiliary heating system includes buffer tanks, a water source heat pump, and a hot water storage tank. Based on the water temperature conditions of the solar collectors, user-side hot water storage tanks, buffer tanks, and hot water storage tanks, as well as changes in user demand, a suitable loop is selected for operation. The system offers multiple heating modes that can be switched according to user needs, enabling the sharing and absorption of heat from all users throughout the year, improving the system's heating reliability and overall energy utilization rate.

Description

Technical Field

[0001] This invention relates to the field of solar thermal energy storage and heating technology, specifically a heating system and its control method based on a heat pump to increase the temperature difference of energy storage. Background Technology

[0002] Solar thermal energy storage heating technology stores collected solar radiation energy in a thermal storage medium to provide heat to users. Compared with conventional solar heating technology, it can effectively overcome the shortcomings of intermittent and unstable solar energy and is one of the ways to achieve continuous and reliable operation of solar heating systems.

[0003] In solar thermal energy storage heating technology, water tank storage is widely used in large-scale solar thermal energy storage heating systems due to its advantages of high heat storage density and efficiency. It typically connects solar collectors directly to the hot water storage tank or indirectly via heat exchangers to store solar radiation energy in the tank. However, these systems generally suffer from three problems: First, land constraints around towns make it difficult to establish centralized solar collector fields, thus hindering the development of large-scale centralized solar heating systems. Second, the outlet water temperature of the solar collectors is greatly affected by solar radiation intensity, resulting in a short period of direct solar heating in winter, which limits the system's solar energy utilization rate. Furthermore, during the heating season, as the hot water storage tank continuously supplies heat to users, its temperature gradually decreases, potentially leading to insufficient heat supply. This often necessitates the activation of auxiliary heating equipment (such as boilers) to supplement the insufficient heat, resulting in low system reliability and overall energy utilization efficiency. Summary of the Invention

[0004] To address the shortcomings of the prior art, this invention provides a heating system and its control method based on a heat pump to enhance the temperature difference of energy storage. It features multiple heating modes that can be switched according to user needs, enabling the sharing and consumption of heat from all users throughout the year, thereby improving the system's heating reliability and overall energy utilization rate.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A heating system based on a heat pump to enhance the temperature difference of energy storage includes an auxiliary heating system for supplementing the heating network and multiple heating users connected in parallel with the heating network. The auxiliary heating system is equipped with a hot water storage tank. Each heating user is equipped with an outdoor solar collector and an indoor hot water supply device and radiant heat dissipation device. Each heating user is also equipped with a user-side hot water storage tank. The solar collector is connected to the user-side hot water storage tank and a first circulating water pump is installed to form a user-side decentralized heat collection-storage circulation loop. The user-side hot water storage tank is sequentially connected to a first electric valve, a second electric valve, and a third electric valve. A user-side heating circulation loop is formed by two circulating water pumps, a hot water supply device, and a radiant heat dissipation device. The hot water supply device and the radiant heat dissipation device are arranged in parallel. A third electric valve is installed upstream of the parallel branch of the hot water supply device, and a second electric valve is installed upstream of the parallel branch of the radiant heat dissipation device. The user-side hot water storage tank is also connected to the hot water pipe and return water pipe of the heating network and is equipped with a third circulating water pump to form a user-network circulation loop. The auxiliary heating system is equipped with a buffer storage tank and a water source heat pump. The buffer storage tank is connected to the hot water pipe and return water pipe of the heating network and is equipped with a fourth circulating water pump. A buffer tank-pipeline circulation loop is formed. The pipeline connecting the buffer tank and the hot water pipe is equipped with a fourth electric valve. The outlet of the hot water storage tank is connected to the buffer tank sequentially via a seventh electric valve, a sixth electric valve, and a fifth circulating water pump. The return end of the hot water storage tank is connected to the buffer tank sequentially via an eighth valve and a seventh valve. Together with the buffer tank-pipeline circulation loop, this forms a water tank heat storage-direct heating circulation loop. The water source heat pump is equipped with hot water pump pipes and cold water pump pipes. The outlet of the hot water pump pipe is connected to the buffer tank sequentially via a sixth electric valve and a fifth circulating water pump. The return end of the hot water pump pipe... The cold water pump pipe connects to the buffer tank via the sixth circulating water pump and the fifth electric valve. The outlet of the cold water pump pipe connects to the buffer tank via the seventh valve, and the return end of the cold water pump pipe connects to the buffer tank via the twelfth valve. Together with the buffer tank-pipeline circulation loop, they form the buffer tank-water source heat pump heating circulation loop. At the same time, the return end of the hot water pump pipe connects to the outlet of the hot water storage tank via the sixth circulating water pump and the eighth electric valve. The return end of the cold water pump pipe connects to the return end of the hot water storage tank via the eleventh valve. Together with the buffer tank-pipeline circulation loop, they form the hot water storage tank-water source heat pump heating circulation loop.

[0007] A control method for a heating system based on a heat pump to increase the temperature difference of energy storage includes the following steps:

[0008] During the summer and transitional seasons, only domestic hot water is supplied. The first circulating water pump, the first electric valve, the second circulating water pump, and the third electric valve are turned on. Only the user-side decentralized heat collection-storage circulation loop and the user-side heating circulation loop are in operation. The user-side hot water storage tank stores hot water heated by the solar collector and delivers it to the hot water supply device. If there is excess heat in the user-side hot water storage tank in addition to supplying domestic hot water, the third circulating water pump, the fourth circulating water pump, the fourth electric valve, the fifth circulating water pump, the sixth electric valve, the seventh valve, the seventh electric valve, and the eighth valve are turned on at the same time. The user-pipeline circulation loop and the water tank storage-direct heating circulation loop are also in operation simultaneously, sending the hot water with excess heat in the user-side hot water storage tank to the hot water storage tank for centralized storage.

[0009] At the beginning of the heating season, domestic hot water is supplied simultaneously with heating. When the solar collectors can meet the demand, the first circulating water pump, the first electric valve, the second circulating water pump, the second electric valve, and the third electric valve are opened. There is no heat exchange with the heating network. Only the user-side decentralized collector-storage circulation loop and the user-side heating circulation loop are in operation. When the solar collectors are insufficient to meet the demand, the third circulating water pump, the fourth circulating water pump, the fourth electric valve, the fifth electric valve, the fifth circulating water pump, the sixth electric valve, the seventh valve, the water source heat pump, the sixth circulating water pump, and the twelfth valve are opened simultaneously. The user-network circulation loop and the buffer tank-water source heat pump heating circulation loop are also in operation. The water source heat pump heats the water in the buffer tank and then sends it to the heating users with insufficient heating through the heating network.

[0010] During the heating season, when the heat from the solar collectors and the buffer tank heated by the water source heat pump cannot meet the heating demand, the fifth circulating water pump, the sixth electric valve, the seventh valve, the seventh electric valve, and the eighth valve are activated. The user-pipeline circulation loop and the water tank storage-direct heating circulation loop operate, extracting heat directly from the hot water storage tank and supplementing the insufficient heating through the heating pipeline network until the water temperature in the hot water storage tank drops to a level that cannot meet the heating demand. At this point, the fifth circulating water pump, the sixth electric valve, the seventh valve, the eighth electric valve, the eleventh valve, and the sixth circulating water pump are activated simultaneously, and the hot water storage tank-water source heat pump heating circulation loop also operates synchronously. The water source heat pump raises the water temperature in the hot water storage tank and then delivers it to the buffer tank, where it is supplemented by the insufficient heating through the heating pipeline network.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. This invention sets up a user-side decentralized heat collection-storage circulation loop, a user-side heating circulation loop, and a user-pipeline circulation loop. By collecting solar heat at decentralized individual user sides and using the pipeline network to link the heat transmission of each user side, an auxiliary heating system is set up to coordinate the differences in heat utilization among different users, so as to realize the sharing and consumption of heat from all users throughout the year and fully improve the utilization rate of solar energy.

[0013] 2. Multiple heating modes are set up. Based on the water temperature of the solar collector, user-side hot water storage tank, buffer tank, and hot water storage pool, as well as changes in user-side demand, the appropriate circulation loop is selected to operate, so that the system's heat supply matches the user's heat demand, effectively improving the system's heating reliability.

[0014] 3. By setting up a shared water source heat pump in the buffer tank-water source heat pump heating loop and the hot water storage tank-water source heat pump heating loop, the water temperature of the buffer tank and the hot water storage tank is increased, the heating time is extended, the heat storage capacity is fully utilized, the use of auxiliary heat sources is effectively reduced, and the overall energy utilization rate of the system is improved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the heating system of the present invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] like Figure 1As shown, a heating system based on a heat pump to enhance the temperature difference of energy storage includes an auxiliary heating system for supplementing the heating network and multiple heating users connected in parallel with the heating network. The auxiliary heating system is equipped with a hot water storage tank 27. Each heating user is equipped with an outdoor solar collector 1 and an indoor hot water supply device 9 and a radiant heat dissipation device 12. Each heating user is equipped with a user-side hot water storage tank 4. The solar collector 1 and the user-side hot water storage tank 4 are connected and equipped with a first circulating water pump 2 to form a user-side decentralized heat collection-storage circulation loop. The user-side hot water storage tank 4 is sequentially connected to a first electric valve 5, a second circulating water pump 6, and a heat pump... The water supply device 9 and the radiant heat dissipation device 12 constitute a user-side heating circulation loop. The hot water supply device 9 and the radiant heat dissipation device 12 are arranged in parallel. A third electric valve 8 is installed upstream of the parallel branch of the hot water supply device 9, and a second electric valve 7 is installed upstream of the parallel branch of the radiant heat dissipation device 12. The user-side hot water storage tank 4 is also connected to the hot water pipe and return water pipe of the heating network and is equipped with a third circulating water pump 14 to form a user-network circulation loop. The auxiliary heating system is equipped with a buffer storage tank 18 and a water source heat pump 31. The buffer storage tank 18 is connected to the hot water pipe and return water pipe of the heating network and is equipped with a fourth circulating water pump 16 to form a buffer storage tank-network circulation loop. The circulation loop includes a fourth electric valve 17 connecting the buffer tank 18 to the hot water pipe. The outlet of the hot water storage tank 27 is connected to the buffer tank 18 via a seventh electric valve 24, a sixth electric valve 22, and a fifth circulating water pump 21. The return end of the hot water storage tank 27 is connected to the buffer tank 18 via an eighth valve 25 and a seventh valve 23. Together with the buffer tank-pipeline circulation loop, this forms a water tank heat storage-direct heating circulation loop. The water source heat pump 31 includes hot water pump pipes and cold water pump pipes. The outlet of the hot water pump pipe is connected to the buffer tank 18 via a sixth electric valve 22 and a fifth circulating water pump 21. The return end of the hot water pump pipe... The cold water pump pipe is connected to the buffer tank 18 via the sixth circulating water pump 32 and the fifth electric valve 19. The outlet of the cold water pump pipe is connected to the buffer tank 18 via the seventh valve 23, and the return end of the cold water pump pipe is connected to the buffer tank 18 via the twelfth valve 33. Together with the buffer tank-pipeline circulation loop, they form the buffer tank-water source heat pump heating circulation loop. At the same time, the return end of the hot water pump pipe is connected to the outlet of the hot water storage tank 27 via the sixth circulating water pump 32 and the eighth electric valve 29. The return end of the cold water pump pipe is connected to the return end of the hot water storage tank 27 via the eleventh valve 30. Together with the buffer tank-pipeline circulation loop, they form the hot water storage tank-water source heat pump heating circulation loop.

[0018] To facilitate the disconnection of pipelines in case of electric valve failure or other special circumstances, valves can be installed on each pipeline for manual control. For example, a first valve 3 can be installed on the user-side distributed heat collection-storage circulation loop, a fourth valve 13 can be installed on the user-side heating circulation loop, a second valve 10 can be installed downstream of the parallel branch of the hot water supply device 9, a third valve 11 can be installed downstream of the parallel branch of the radiant heat dissipation device 12, a fifth valve 15 can be installed on the user-pipeline circulation loop, a sixth valve 20 can be installed on the buffer tank-pipeline circulation loop, and a ninth valve 26 and a tenth valve 28 can be installed at the outlet and return ends of the hot water storage tank 27, respectively.

[0019] like Figure 1 As shown, a control method for a heating system based on a heat pump to increase the temperature difference of energy storage includes the following operating conditions:

[0020] During the summer and transitional seasons, only domestic hot water is supplied. The first circulating water pump 2, the first electric valve 5, the second circulating water pump 6, and the third electric valve 8 are turned on. Only the user-side decentralized heat collection-storage circulation loop and the user-side heating circulation loop are in operation. The user-side hot water storage tank 4 stores the hot water heated by the solar collector 1 and delivers it to the hot water supply device 9. If the user-side hot water storage tank 4 has excess heat in addition to supplying domestic hot water, the third circulating water pump 14, the fourth circulating water pump 16, the fourth electric valve 17, the fifth circulating water pump 21, the sixth electric valve 22, the seventh valve 23, the seventh electric valve 24, and the eighth valve 25 are turned on at the same time. The user-pipeline circulation loop and the water tank storage-direct heating circulation loop are also in operation at the same time, and the hot water with excess heat in the user-side hot water storage tank 4 is sent to the hot water storage tank 27 for centralized storage.

[0021] At the beginning of the heating season, domestic hot water is supplied while heating is being provided. When the solar collector 1 can meet the demand simultaneously, the first circulating water pump 2, the first electric valve 5, the second circulating water pump 6, the second electric valve 7, and the third electric valve 8 are turned on. There is no heat exchange with the heating network. Only the user-side decentralized heat collection-storage circulation loop and the user-side heating circulation loop are in operation. When the solar collector 1 is insufficient to meet the demand simultaneously, the third circulating water pump 14, the fourth circulating water pump 16, the fourth electric valve 17, the fifth electric valve 19, the fifth circulating water pump 21, the sixth electric valve 22, the seventh valve 23, the water source heat pump 31, the sixth circulating water pump 32, and the twelfth valve 33 are turned on simultaneously. The user-network circulation loop and the buffer tank-water source heat pump heating circulation loop are also in operation. The water source heat pump 31 heats the water in the buffer tank 18 and then sends it to the heating users with insufficient heating through the heating network.

[0022] During the heating season, when the heat from the solar collector 1 and the buffer storage tank 18 heated by the water source heat pump 31 is insufficient to meet the heating demand, the fifth circulating water pump 21, the sixth electric valve 22, the seventh valve 23, the seventh electric valve 24 and the eighth valve 25 are activated. The user-pipeline circulation loop and the water tank storage-direct heating circulation loop operate. Heat is directly extracted from the hot water storage tank 27 and supplemented through the heating pipeline network to make up for the insufficient heating. When the water temperature in the hot water storage tank 27 drops to a level that cannot meet the heating demand, the fifth circulating water pump 21, the sixth electric valve 22, the seventh valve 23, the eighth electric valve 29, the eleventh valve 30 and the sixth circulating water pump 32 are activated simultaneously. The hot water storage tank-water source heat pump heating circulation loop also operates synchronously. The water source heat pump 31 is used to raise the water temperature in the hot water storage tank 27 and then deliver it to the buffer storage tank 18, and then supplement the insufficient heating through the heating pipeline network.

[0023] This solution targets regions rich in solar energy resources, such as Tibet. It involves installing decentralized solar collectors 1 and user-side hot water storage tanks 4 at heating users (especially suitable for scattered individual buildings in urban areas). Solar heat is collected on the roofs of these scattered individual buildings, and the heat transfer between users is interconnected via a pipeline network. Simultaneously, centralized heat storage and supply coordinate the differences in heat utilization among different users. In summer and transitional seasons, in addition to domestic hot water supply, excess solar heat is transferred through the pipeline network to a cross-seasonal hot water storage tank 27 for storage. In winter, this is used to supplement the heating and domestic hot water needs that the decentralized solar collectors 1 cannot meet, thus achieving year-round heat sharing and utilization among all users and maximizing solar energy utilization. Furthermore, by installing a water source heat pump 31, the heating time of the buffer tank 18 and the hot water storage tank 27 is extended, maximizing the utilization of stored heat, effectively reducing the use of auxiliary heat sources, and improving the overall energy efficiency of the system.

[0024] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and not restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0025] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A heating system based on a heat pump to enhance the temperature difference of energy storage, comprising an auxiliary heating system for supplementing the heating network and multiple heating users connected in parallel with the heating network, wherein the auxiliary heating system is equipped with a hot water storage tank (27), and each heating user is equipped with an outdoor solar collector (1) and an indoor hot water supply device (9) and a radiant heat dissipation device (12), characterized in that: Each heating user is equipped with a user-side hot water storage tank (4). The solar collector (1) is connected to the user-side hot water storage tank (4) and a first circulating water pump (2) is installed to form a user-side decentralized heat collection-storage circulation loop. The user-side hot water storage tank (4) is sequentially connected to a first electric valve (5), a second circulating water pump (6), a hot water supply device (9), and a radiant heat dissipation device (12) to form a user-side heating circulation loop. The hot water supply device (9) and the radiant heat dissipation device (12) are arranged in parallel, and a third electric valve (8) is installed upstream of the parallel branch of the hot water supply device (9). 2) A second electric valve (7) is installed upstream of the parallel branch. The user-side hot water storage tank (4) is also connected to the hot water pipe and return water pipe of the heating network and a third circulating water pump (14) is installed to form a user-network circulation loop. The auxiliary heating system is equipped with a buffer storage tank (18) and a water source heat pump (31). The buffer storage tank (18) is connected to the hot water pipe and return water pipe of the heating network and a fourth circulating water pump (16) is installed to form a buffer storage tank-network circulation loop. The pipe connecting the buffer storage tank (18) and the hot water pipe is equipped with a fourth electric valve (17). The outlet of the hot water storage tank (27) passes through a seventh electric valve (24) and a sixth electric valve in sequence. The electric valve (22) and the fifth circulating water pump (21) are connected to the buffer tank (18). The return water end of the hot water storage tank (27) is connected to the buffer tank (18) in sequence through the eighth valve (25) and the seventh valve (23), and together with the buffer tank-pipeline circulation loop, they form a water tank heat storage-direct heating circulation loop. The water source heat pump (31) is equipped with a hot water pump pipe and a cold water pump pipe. The outlet end of the hot water pump pipe is connected to the buffer tank (18) in sequence through the sixth electric valve (22) and the fifth circulating water pump (21), and the return water end of the hot water pump pipe is connected to the buffer tank (18) in sequence through the sixth circulating water pump (32) and the fifth electric valve (19). The cold water pump pipe outlet is connected to the buffer tank (18) via the seventh valve (23), and the cold water pump pipe return is connected to the buffer tank (18) via the twelfth valve (33). Together with the buffer tank-pipeline circulation loop, they form the buffer tank-water source heat pump heating circulation loop. Meanwhile, the hot water pump pipe return is connected to the outlet of the hot water storage tank (27) via the sixth circulating water pump (32) and the eighth electric valve (29). The cold water pump pipe return is connected to the return of the hot water storage tank (27) via the eleventh valve (30). Together with the buffer tank-pipeline circulation loop, they form the hot water storage tank-water source heat pump heating circulation loop.

2. A control method for a heating system based on a heat pump to increase the temperature difference of energy storage, characterized in that: The control method of the heating system according to claim 1 includes the following steps: During the summer and transitional seasons, only domestic hot water is supplied. The first circulating water pump (2), the first electric valve (5), the second circulating water pump (6), and the third electric valve (8) are turned on. Only the user-side decentralized heat collection-storage circulation loop and the user-side heating circulation loop are in operation. The user-side hot water storage tank (4) stores hot water heated by the solar collector (1) and delivers it to the hot water supply device (9). If the user-side hot water storage tank (4) has excess heat in addition to supplying domestic hot water, the third circulating water pump (14), the fourth circulating water pump (16), the fourth electric valve (17), the fifth circulating water pump (21), the sixth electric valve (22), the seventh valve (23), the seventh electric valve (24), and the eighth valve (25) are turned on at the same time. The user-pipeline circulation loop and the water tank heat storage-direct heating circulation loop are also in operation at the same time. The hot water with excess heat in the user-side hot water storage tank (4) is sent to the hot water storage pool (27) for centralized storage. At the beginning of the heating season, domestic hot water is supplied while heating is being provided. When the solar collector (1) can meet the demand simultaneously, the first circulating water pump (2), the first electric valve (5), the second circulating water pump (6), the second electric valve (7), and the third electric valve (8) are turned on. There is no heat exchange with the heating network. Only the user-side decentralized heat collection-storage circulation loop and the user-side heating circulation loop are in operation. When the solar collector (1) is insufficient to meet the demand simultaneously, the third circulating water pump (14) is turned on at the same time. The fourth circulating water pump (16), the fourth electric valve (17), the fifth electric valve (19), the fifth circulating water pump (21), the sixth electric valve (22), the seventh valve (23), the water source heat pump (31), the sixth circulating water pump (32) and the twelfth valve (33), the user-pipeline circulation loop and the buffer tank-water source heat pump heating circulation loop also operate synchronously. The water source heat pump (31) heats the water in the buffer tank (18) and then sends it to the heating users with insufficient heating through the heating pipeline network. During the heating season, when the heat from the solar collector (1) and the buffer storage tank (18) heated by the water source heat pump (31) is insufficient to meet the heating demand, the fifth circulating water pump (21), the sixth electric valve (22), the seventh valve (23), the seventh electric valve (24), and the eighth valve (25) are activated. The user-pipeline circulation loop and the water tank storage-direct heating circulation loop operate, and heat is directly extracted from the hot water storage tank (27) and supplemented through the heating pipeline network to meet the insufficient heating demand until the heat supply is fully supplied. When the water temperature in the hot water storage tank (27) drops to a level that cannot meet the heating demand, the fifth circulating water pump (21), the sixth electric valve (22), the seventh valve (23), the eighth electric valve (29), the eleventh valve (30), and the sixth circulating water pump (32) are opened simultaneously. The hot water storage tank-water source heat pump heating circulation loop also operates synchronously. The water source heat pump (31) is used to raise the water temperature in the hot water storage tank (27) and then transport it to the buffer storage tank (18). The insufficient heating is then supplemented through the heating network.

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