A dual-heat-storage coupled heat supply system and a control method thereof

Abstract

This application discloses a dual-heat storage coupled heating system and its control method. The heating system includes a heat pump unit, a gas generator, a water supply pipeline, a first heat storage device, and a second heat storage device. The first heat storage device is deployed on the medium circulation pipeline of the heat pump unit and connected to the gas generator. The first heat storage device stores the waste heat generated by the gas generator during operation and releases the stored waste heat to the heat pump unit during operation. The second heat storage device is connected to the water supply pipeline, so that a portion of the water supplied from the heat pump unit to the water supply pipeline is stored in the second heat storage device and then flows back to the heat pump unit. This application forms a dual-heat storage coupled system by setting up a first heat storage device and a second heat storage device. By storing the waste heat generated by the gas furnace during operation through the first heat storage device, the waste heat recovery and utilization are decoupled in time, avoiding waste of waste heat and improving energy utilization efficiency. The second heat storage device provides an energy buffer for the main heat source formed by the heat pump and gas unit, storing the heat energy generated by the heat pump during periods of low electricity prices and releasing it preferentially during periods of high energy prices. This reduces the operating cost of the heating system and also smooths out water temperature fluctuations during heat source switching, avoiding discomfort to users caused by heat source switching.

Description

Technical Field

[0001] This application relates to the field of heating technology, and in particular to a dual-heat storage coupled heating system and its control method. Background Technology

[0002] Gas-fired boiler and heat pump combined heating systems have attracted widespread attention due to their combination of high efficiency and stability. These systems can switch operating modes based on fluctuations in electricity and gas prices to reduce heating costs. However, existing gas-fired boiler and heat pump combined heating systems generally rely solely on switching between gas and electricity prices. During peak electricity price periods or at the moment of heat source switching, the system's output heat may fluctuate or even interrupt, affecting user experience. Furthermore, the operation of the gas boiler generates a large amount of waste heat from flue gas, which is usually directly released into the atmosphere, resulting in energy waste.

[0003] Therefore, existing technologies still need to be improved and enhanced. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a dual-heat storage coupled heating system and its control method, addressing the shortcomings of the existing technology.

[0005] To address the aforementioned technical problems, the first aspect of this application provides a dual-heat storage coupled heating system, wherein the dual-heat storage coupled heating system specifically includes: Heat pump devices; Gas appliances; The water supply pipeline is connected to both the water supply inlet of the heat pump device and the water supply inlet of the gas device. The first heat storage device is deployed on the medium circulation pipeline of the heat pump device and connected to the gas device; the first heat storage device is used to store the exhaust waste heat generated when the gas device is working, and release the stored exhaust waste heat to the heat pump device when the heat pump device is running. The second heat storage device is connected to the water supply pipeline, so that a portion of the water supplied by the heat pump device flowing into the water supply pipeline is stored in the second heat storage device and then flows back to the heat pump device.

[0006] The dual-heat storage coupled heating system includes a heat pump device comprising a compressor, a condenser, a throttling valve, and an evaporator. The compressor, condenser, throttling valve, and evaporator are connected in sequence to form a medium circulation loop. The first heat storage device is deployed on the medium circulation pipeline between the evaporator and the compressor. The exhaust port of the gas device is connected to the first heat storage device through a pipeline, so that the flue gas generated when the gas device is working stores the waste heat of the exhaust gas in the first heat storage device before being discharged.

[0007] A second aspect of this application provides a control method for a dual-heat storage coupled heating system, used to control the dual-heat storage coupled heating system as described above, the control method specifically including: Obtain user load, unit cost of heat pump heating, unit cost of gas-fired heating, and unit cost of second thermal storage device heating. With user load as a constraint and minimum heating cost as the objective, target heating equipment is selected in the dual-heat storage coupled heating system based on the unit cost of heat pump heating, gas device heating, and second heat storage device heating. Control the target heating equipment to supply heat.

[0008] The control method for the dual-heat storage coupled heating system, wherein selecting the target heating equipment in the dual-heat storage coupled heating system based on the unit cost of heat pump heating, the unit cost of gas heating device heating, and the unit cost of second heat storage device, with user load as a constraint and minimum heating cost as the objective, specifically includes: Based on the unit cost of heat pump heating, the unit cost of gas-fired heating, and the unit cost of the second heat storage device, the first heating device with the lowest unit cost is selected in the dual heat storage coupled heating system. If the first heating equipment meets the user's load, then the first heating equipment will be used as the target heating equipment. If the first heating equipment fails to meet the user load, a second heating equipment is selected based on the unit heating cost of other heating equipment besides the first heating equipment, and the first heating equipment and the second heating equipment are used as target heating equipment. If the first and second heating devices fail to meet the user load, then all heating devices in the dual-heat storage coupled heating system will be used as the target heating devices.

[0009] The control method for the dual-thermal-storage coupled heating system, wherein the unit cost of heating from the second thermal storage device is 0, or is calculated based on a preset energy storage electricity price threshold, wherein the process of obtaining the energy storage electricity price threshold specifically includes: To obtain the energy efficiency ratio of the heat pump unit, the gas price, the thermal efficiency of the gas furnace, and the insulation efficiency; The initial energy storage price is determined based on the energy efficiency ratio and the gas price, and the ratio of the initial energy storage price to the thermal efficiency of the gas furnace is multiplied by the insulation efficiency to obtain the energy storage price threshold.

[0010] The control method for the dual-heat storage coupled heating system, wherein when the target heating device is a heat pump device, controlling the heating of the target heating device specifically includes: Start the heat pump unit and monitor the real-time electricity price and current heat load; When the real-time electricity price is lower than the preset energy storage electricity price threshold and the current heat load is lower than the preload threshold, the second heat storage device is connected to the water supply pipeline, so that part of the hot water in the water supply pipeline flows through the second heat storage device for heat storage and part of the hot water is supplied to the user. When the real-time electricity price is lower than the preset energy storage electricity price threshold, or when the current heat load is equal to or higher than the preload threshold, the second heat storage device is disconnected from the water supply pipeline, so that all the hot water in the water supply pipeline is supplied to the user.

[0011] In the control method of the dual-heat storage coupled heating system, the preload threshold is determined based on the rated output of the heat pump device.

[0012] The control method for the dual-heat storage coupled heating system, wherein when the target heating device is a heat pump, controlling the heating of the target heating device further includes: When the real-time electricity price is equal to or higher than the preset energy storage electricity price threshold, the heat pump device is turned off or the heat pump load of the heat pump device is reduced, and the second heat storage device is connected to the water supply pipeline, and the water is supplied to the user side through the second heat storage device or the second heat storage device and the heat pump device. During the process of supplementing the heat pump device to supply the user side through the second heat storage device, the heat storage status of the second heat storage device is monitored, and the heat pump device is adjusted according to the heat storage status.

[0013] The control method for the dual-heat storage coupled heating system, wherein when the target heating device is a gas-fired device, controlling the heating of the target heating device specifically includes: Start the gas appliance and disconnect the second heat storage device from the water supply pipeline; The flue gas generated by the control gas device is discharged after passing through the first heat storage device, so that the first heat storage device stores the waste heat carried by the flue gas.

[0014] The control method for the dual-heat storage coupled heating system, wherein when the target heating equipment includes a heat pump device, during the operation of the heat pump device, the heat pump device uses the first heat storage device to preheat the circulating medium flowing into the evaporator of the heat pump device, so as to recover the exhaust waste heat stored in the first heat storage device.

[0015] A third aspect of this application provides a computer-readable storage medium storing one or more programs that can be executed by one or more processors to implement the steps in the cross-domain cluster system distributed secure formation control method as described above.

[0016] A fourth aspect of this application provides a terminal device, which includes: a processor and a memory; The memory stores a computer-readable program that can be executed by the processor; When the processor executes the computer-readable program, it implements the steps in the distributed secure formation control method for cross-domain cluster systems as described above.

[0017] Beneficial Effects: This application provides a dual-heat storage coupled heating system and its control method. The heating system includes a heat pump device, a gas generator, a water supply pipeline, a first heat storage device, and a second heat storage device. The first heat storage device is deployed on the medium circulation pipeline of the heat pump device and connected to the gas generator. The first heat storage device stores the waste heat generated by the gas generator during operation and releases the stored waste heat to the heat pump device during operation. The second heat storage device is connected to the water supply pipeline, so that a portion of the water supplied from the heat pump device to the water supply pipeline is stored in the second heat storage device and then flows back to the heat pump device. This application forms a dual-heat storage coupled system by setting up a first heat storage device and a second heat storage device. By storing the waste heat generated by the gas furnace during operation through the first heat storage device, the waste heat recovery and utilization are decoupled in time, avoiding waste of waste heat and improving energy utilization efficiency. Meanwhile, the second heat storage device provides an energy buffer for the main heat source formed by the heat pump and gas unit, storing the heat energy generated by the heat pump during periods of low electricity prices and releasing it preferentially during periods of high energy prices. This reduces the operating cost of the heating system and also smooths out water temperature fluctuations during heat source switching, avoiding discomfort to users caused by heat source switching. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a dual-heat storage coupled heating system provided in an embodiment of this application.

[0020] Figure 2 A flowchart illustrating the control method of a dual-heat storage coupled heating system provided in an embodiment of this application. Detailed Implementation

[0021] This application provides a dual-heat storage coupled heating system and its control method. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.

[0022] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0023] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0024] It should be understood that the sequence number and size of each step in this embodiment do not imply the order of execution. The execution order of each process is determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application embodiment.

[0025] The application content will be further explained below with reference to the accompanying drawings and the description of the embodiments.

[0026] This embodiment provides a dual-heat storage coupled heating system, such as... Figure 1 As shown, the heating system specifically includes a heat pump device, a gas device, a water supply pipeline, a first heat storage device, and a second heat storage device. Both the heat pump device and the gas device are used to provide heat to users, and the water inlets of the heat pump device and the gas device are connected to the water supply pipeline to transport the generated hot water to the user side through the water supply pipeline.

[0027] The first heat storage device is deployed on the medium circulation pipeline of the heat pump unit and connected to the exhaust port of the gas unit via a flue gas pipe. This medium circulation pipeline provides the circulating medium (such as air, water, or other working fluid) to the evaporator of the heat pump unit. When the gas unit is operating, the flue gas generated by the gas unit flows through the first heat storage device before being discharged, allowing the first heat storage device to absorb and store the waste heat carried in the flue gas. When the heat pump unit is operating, the circulating medium flowing through the medium circulation pipeline first passes through the first heat storage device, using the waste heat stored in the first heat storage device to preheat the circulating medium, thereby increasing the evaporation temperature and operating efficiency of the heat pump unit, achieving the recovery and efficient utilization of waste heat. Simultaneously, by deploying the first heat storage device on the medium circulation pipeline, and then using the first heat storage device to store waste heat during gas operation and release the stored waste heat during heat pump operation, the time decoupling of waste heat recovery and utilization is achieved, avoiding the waste heat waste caused by the asynchronous operation of the gas unit and the heat pump unit.

[0028] In one embodiment, the heat pump device includes a compressor, a condenser, a throttling valve, and an evaporator. The compressor, condenser, throttling valve, and evaporator are connected in sequence to form a medium circulation loop. The first heat storage device is deployed on the medium circulation pipeline between the evaporator and the compressor. The exhaust port of the gas device is connected to the first heat storage device through a pipeline, so that the flue gas generated when the gas device is working stores the waste heat of the exhaust gas in the first heat storage device before being discharged. That is, the first heat storage device is used to store the waste heat carried by the flue gas generated by the gas device. Specifically, the first heat storage device may be equipped with a phase change heat storage material. When the flue gas generated by the gas device flows through the first heat storage device, the phase change heat storage material in the first heat storage device will absorb the waste heat of the flue gas and undergo a phase change, thereby storing the absorbed waste heat of the flue gas. When the heat pump device is running and the circulating medium flows through the first heat storage device, the phase change heat storage material will release the stored heat to preheat the circulating medium. This phase change heat storage method can store more heat per unit volume and maintain a relatively stable temperature during heat release, which is beneficial for improving the preheating effect and stability of the circulating medium, thereby ensuring that the heat pump device can operate continuously and efficiently.

[0029] The second thermal storage device is connected to the water supply pipeline via a branch pipeline, and a control valve is installed on the branch pipeline to control the opening and closing of the connection between the second thermal storage device and the water supply pipeline. This allows hot water generated by the heat pump to flow into the second thermal storage device through the branch pipeline, where it completes heat storage before flowing back to the inlet of the heat pump device for reheating. This converts low-priced electricity during off-peak hours into stored heat energy, and also stores excess heat generated by the heat pump device. Specifically, when the heat pump device is operating, if the unit heating cost of the heat pump device is lower than that of the second thermal storage device, and the current heat load is below the preload threshold, the control valve opens to connect the second thermal storage device to the water supply pipeline. A portion of the hot water produced by the heat pump device is diverted to the second thermal storage device, where it completes heat storage before flowing back to the inlet of the heat pump device for reheating. This converts low-priced electricity during off-peak hours into stored heat energy. In addition, the second thermal storage device also has an energy release function. When the unit heating cost of the second thermal storage device is lower than the unit heating cost of the heat pump device and the gas device, and the second thermal storage device can provide heat, the control valve opens to connect the second thermal storage device to the water supply pipeline. The supply water in the pipeline is then heated by the second thermal storage device before being supplied to the user. In this way, the second thermal storage device not only realizes the spatial and temporal transfer of heat energy produced by the heat pump device, effectively mitigating the impact of electricity price fluctuations on heating costs, but also plays an important buffering role during heat source switching, ensuring the stability and continuity of hot water supply to the user.

[0030] In one embodiment, the inlet of the second heat storage device is connected to the water supply pipeline via a branch pipe, and the connection between the branch pipe and the water supply pipeline is closer to the user side than the connection between the outlet of the heat pump device and the water supply pipeline. This allows the supply water to first pass through the heat pump device and then flow through the connection between the inlet of the second heat storage device and the water supply pipeline, so that the supply water heated by the heat pump device can flow into the second heat storage device. To ensure that the supply water heated by the heat pump device partially flows into the second heat storage device and partially supplies the user side, a first three-way valve can be installed at the connection between the branch pipe and the water supply pipeline. The opening degree of this first three-way valve controls the ratio of supply water flowing into the second heat storage device and supplying the user side.

[0031] Furthermore, a second three-way valve can be installed at the water outlet of the second thermal storage device. This valve connects the water outlet of the second thermal storage device to both the user side and the inlet of the heat pump device. Thus, when the second thermal storage device is in a thermal storage state, the supply water flowing into it can flow back to the inlet of the heat pump device. When the second thermal storage device is in an energy release state, the supply water flowing into it can flow to the user side. The second thermal storage device can contain a heat exchange component and a accumulator containing a heat storage medium (such as water or a phase change material). When the second thermal storage device is in a thermal storage state, the supply water, heated by the heat pump device, flows into the second thermal storage device and exchanges heat with the heat exchange component. The heat exchange component transfers heat to the heat storage medium in the accumulator, allowing the heat to be stored. When the second thermal storage device is in an energy release state, the supply water flowing into it exchanges heat with the heat exchange component, transferring the heat stored in the heat storage medium in the accumulator to the supply water, releasing the heat stored in the heat storage medium.

[0032] Based on the above-mentioned dual-heat storage coupled heating system, such as Figure 2 As shown in the figure, this application provides a control method for a dual-heat storage coupled heating system, which specifically includes: S10. Obtain user load, unit cost of heat pump heating, unit cost of gas-fired heating, and unit cost of second thermal storage device heating. S20. Taking user load as a constraint and minimizing heating cost as the objective, select the target heating equipment in the dual-heat storage coupling heating system based on the unit cost of heat pump heating, the unit cost of gas device heating, and the unit cost of second heat storage device heating. S30. Control the target heating equipment to supply heat.

[0033] Specifically, in step S10, the user load is the user's demand for heat energy, the magnitude of which is affected by various factors such as the number of users, the operating status of the heat-using equipment, and the ambient temperature. In practical applications, user load data can be collected in real time by heat metering devices installed at the user end and transmitted to the system controller, providing a basis for subsequent selection of heating equipment.

[0034] The unit cost of heat pump heating is the cost required for the heat pump device to generate 1 kWh of heat, which can be determined based on the real-time electricity price and the energy efficiency ratio (COP) of the heat pump device at the current ambient temperature. For example, if the real-time electricity price is 0.8 yuan / kWh and the COP of the heat pump device is 2.8 (ambient temperature -5℃), the unit cost of heat pump heating is approximately 0.8 / 2.8 ≈ 0.29 yuan / kWh.

[0035] The unit cost of gas-fired heating is the cost required for the gas-fired unit to generate 1 kWh of heat, which can be determined based on the gas price and the thermal efficiency of the gas-fired unit. For example, if the gas price is 0.4 yuan / m³, the gas boiler thermal efficiency is 0.9, and the lower calorific value of natural gas is 35.59 MJ / m³ (approximately 8.5 kWh / m³), then the unit cost of gas-fired heating is approximately 3.0 / (8.5 × 0.9) ≈ 0.39 yuan / kWh.

[0036] The unit cost of heating for the second thermal storage device is the cost required to generate 1 kWh of heat. Since the second thermal storage device stores some of the heat carried by the supply water generated by the heat pump when the rated heating capacity of the heat pump exceeds the user load, it can be used to recover excess heat generated by the heat pump. Therefore, the unit cost of heating for the second thermal storage device can be directly set to 0. Of course, in practical applications, since the heat pump also incurs costs in preparing the supply water flowing to the second thermal storage device, the cost can also be determined based on the energy storage electricity price threshold and the heat loss rate. For example, if the energy storage electricity price threshold for the second thermal storage device is 1.52 yuan / kWh and the heat loss rate during the storage process is 5%, then the unit cost of heating for the second thermal storage device is 1.52 / (1-5%)≈1.6 yuan / kWh. The process of obtaining the energy storage electricity price threshold specifically includes: To obtain the energy efficiency ratio of the heat pump unit, the gas price, the thermal efficiency of the gas furnace, and the insulation efficiency; The initial energy storage price is determined based on the energy efficiency ratio and the gas price, and the ratio of the initial energy storage price to the thermal efficiency of the gas furnace is multiplied by the insulation efficiency to obtain the energy storage price threshold.

[0037] Specifically, the energy efficiency ratio (EER) of a heat pump unit can be obtained by consulting the product parameter manual or by conducting performance tests under standard operating conditions. For example, under conditions of an ambient temperature of 25°C and an inlet water temperature of 15°C, the heat pump unit can be continuously run, and its heating capacity and input power recorded to obtain the EER. The gas price is based on the gas price published by the gas supply department in the area where the dual-storage coupled heating system is located; for example, the gas price in a certain region is 4.2 yuan / cubic meter. The thermal efficiency of the gas boiler can be obtained from the product parameters of the gas appliance; for example, the thermal efficiency of the gas boiler is 0.9. The insulation efficiency is determined based on the thermal conductivity and thickness of the insulation material of the second heat storage device and the ambient temperature. For example, after heating the second heat storage device to the set temperature, the temperature drop per unit time is recorded without external heating, and the heat loss is calculated based on the heat capacity of the second heat storage device to obtain the insulation efficiency.

[0038] Furthermore, after obtaining the energy efficiency ratio (EER) of the heat pump device, the gas price, the thermal efficiency of the gas furnace, and the insulation efficiency, the energy storage electricity price threshold is calculated based on these parameters. The formula for calculating the energy storage electricity price threshold can be: , in, Indicates the energy efficiency ratio of a heat pump unit. Indicates the price of natural gas. Indicates the thermal efficiency of the gas furnace. This indicates the insulation efficiency.

[0039] For example: Gas price The energy efficiency ratio of the heat pump unit is 0.45 yuan / kWh. =3.2, gas furnace efficiency =0.9, insulation efficiency =0.95, then the energy storage electricity price threshold is (3.2×0.45) / 0.9×0.95≈1.52 yuan / kWh.

[0040] Furthermore, in step S20, when selecting the target heating equipment in the dual-heat storage coupled heating system, the goal is to minimize the heating cost of the dual-heat storage coupled heating system, while user load is used as a constraint to ensure a stable and demand-satisfying heat supply to the user side. In other words, when selecting the target heating equipment from the heat pump unit, gas furnace unit, and second heat storage unit in the dual-heat storage coupled heating system, the selection is based on minimizing operating costs while meeting user load requirements. For example, an objective function corresponding to the operating cost can be constructed first based on the unit cost of heat pump heating, gas furnace heating, and second heat storage unit heating, and then the objective function can be solved under the constraint of user load to select the target heating equipment.

[0041] In one embodiment, the selection of target heating equipment in the dual-heat storage coupled heating system, based on the unit cost of heat pump heating, gas boiler heating, and second heat storage device, with user load as a constraint and minimum heating cost as the objective, specifically includes: Based on the unit cost of heat pump heating, the unit cost of gas furnace heating, and the unit cost of the second heat storage device, the first heating device with the lowest unit cost is selected in the dual heat storage coupled heating system. If the first heating equipment meets the user's load, then the first heating equipment will be used as the target heating equipment. If the first heating equipment fails to meet the user load, a second heating equipment is selected based on the unit heating cost of other heating equipment besides the first heating equipment, and the first heating equipment and the second heating equipment are used as target heating equipment. If the first and second heating devices fail to meet the user load, then all heating devices in the dual-heat storage coupled heating system will be used as the target heating devices.

[0042] Specifically, the first heating device is the one with the lowest unit heating cost among the heat pump, gas, and second thermal storage devices at the current moment. In other words, the first heating device with the lowest unit heating cost is selected from these three options. Then, it is determined whether the maximum heating capacity of this first heating device can fully cover the user load. If the maximum heating capacity of the first heating device is greater than or equal to the user load, then the first heating device is designated as the target heating device, and it alone undertakes all heating tasks to achieve the lowest possible cost. If the maximum heating capacity of the first heating device cannot fully cover the user load, then the second heating device is selected from the remaining two types of heating devices (i.e., the heat pump, gas, or second thermal storage device remaining after the first heating device in the dual-thermal-storage coupled heating system) to achieve the second lowest unit heating cost at the current moment. Next, the maximum heating capacities of the first and second heating devices are added together to obtain the total heating capacity of the two devices. It is then determined whether this total heating capacity can fully cover the user load. If the total heating capacity can cover the user load, the first and second heating devices are selected as the target heating devices. The first and second heating devices operate collaboratively to meet the user load while minimizing costs. If the total heating capacity cannot cover the user load, all heating devices in the dual-heat storage coupled heating system are activated simultaneously—that is, the heat pump, gas unit, and second heat storage unit are activated. The combined operation of these three devices ensures that the user load is met.

[0043] Furthermore, in step S30, when the target heating device is a heat pump device, controlling the heating of the target heating device specifically includes: Start the heat pump unit and monitor the real-time electricity price and current heat load; When the real-time electricity price is lower than the preset energy storage electricity price threshold and the current heat load is lower than the preload threshold, the second heat storage device is connected to the water supply pipeline, so that part of the hot water in the water supply pipeline flows through the second heat storage device for heat storage and part of the hot water is supplied to the user. When the real-time electricity price is lower than the preset energy storage electricity price threshold, or when the current heat load is equal to or higher than the preload threshold, the second heat storage device is disconnected from the water supply pipeline, so that all the hot water in the water supply pipeline is supplied to the user.

[0044] Specifically, the current heat load refers to the user load at the current moment, and the real-time electricity price is the electricity price actually charged by the power grid at the current moment. The preload threshold is preset, which can be determined based on the utilization load data or based on the rated output of the heat pump device at the current moment. In the embodiments of this application, the preload threshold is determined based on the rated output of the heat pump device at the current moment, and the preload threshold is less than the rated output of the heat pump device at the current moment. For example, the preload threshold is 80% of the rated output of the heat pump device at the current moment.

[0045] It is understood that, in this embodiment, considering the heat storage cost of the second heat storage device, when the heat pump device is used as the target heating equipment for standalone heating, the real-time electricity price is compared with the energy storage electricity price threshold, and the current heat load is compared with the preload threshold to determine whether the heat storage requirements of the second heat storage device are met. These requirements are that the real-time electricity price is lower than the preset energy storage electricity price threshold, and the current heat load is equal to or higher than the preload threshold. Therefore, when the real-time electricity price is lower than the preset energy storage electricity price threshold, or the current heat load is equal to or higher than the preload threshold, it indicates that the heat storage requirements are met, meaning that it is suitable to use the heat pump device for heat storage as the second heat storage device to reduce heat pump operation during periods of higher electricity prices, thereby reducing the overall heating cost. The use of the energy storage electricity price threshold and the preload threshold for constraint is to ensure that the second heat storage device is used when the heat storage cost is low, while meeting user load demands, thus avoiding the impact on heating performance due to excessive heat storage.

[0046] For example, assuming the preload threshold is 80% of the current rated output of the heat pump device, when the real-time electricity price is lower than the energy storage electricity price threshold, and the current heat load is lower than 80% of the current rated output of the heat pump device, the heat pump device is started, and the second heat storage device is connected to the water supply pipeline. Part of the hot water produced by the heat pump device is supplied to the user side, and part flows into the second heat storage device for heat storage. The amount of hot water supplied to the user side and the amount of hot water flowing into the second heat storage device can be determined based on the relationship between the current heat load and the current rated output of the heat pump device. This is adjusted by controlling the opening of the first three-way valve used to connect the second heat storage device and the water supply pipeline. For example, if the current heat load is 70% of the current rated output of the heat pump device, then 70% of the hot water is supplied to the user side, and 30% flows into the second heat storage device.

[0047] Furthermore, when the real-time electricity price is lower than the preset energy storage electricity price threshold, or when the current heat load is equal to or higher than the preload threshold, it indicates that the heat storage requirements of the second heat storage device are not met. In this case, the second heat storage device is disconnected from the water supply pipeline, so that all the hot water in the water supply pipeline is supplied to the user.

[0048] It should be noted that in practical applications, the heat storage cost of the second heat storage device can be disregarded, i.e., the heat storage cost of the second heat storage device can be recorded as 0. Then, when the heat pump device is used as the target heating equipment for independent heating, only the preload threshold can be used as a constraint condition. That is, when the current heat load is lower than the preload threshold, the second heat storage device is connected to the water supply pipeline, so that part of the hot water in the water supply pipeline flows through the second heat storage device for heat storage, and part of the hot water is supplied to the user; conversely, when the current heat load is equal to or higher than the preload threshold, the second heat storage device is disconnected from the water supply pipeline, so that all the hot water in the water supply pipeline is supplied to the user.

[0049] Furthermore, in actual operation, when the target heating equipment is a heat pump device, in addition to storing heat for the second heat storage device through the heat pump device, the second heat storage device can also be used to supplement the heat pump device to reduce operating costs. Therefore, when the target heating equipment is a heat pump device, controlling the heating supply of the target heating equipment further includes: When the real-time electricity price is equal to or higher than the preset energy storage electricity price threshold, the heat pump device is turned off or the heat pump load of the heat pump device is reduced, and the second heat storage device is connected to the water supply pipeline, and the water is supplied to the user side through the second heat storage device or the second heat storage device and the heat pump device. During the process of supplementing the heat pump device to supply the user side through the second heat storage device, the heat storage status of the second heat storage device is monitored, and the heat pump device is adjusted according to the heat storage status.

[0050] Specifically, a preset energy storage electricity price threshold is used as the basis for determining whether supplementary heating can be provided by a second thermal storage device. When the real-time electricity price is equal to or higher than the preset energy storage electricity price threshold, it indicates that the operating cost of using the second thermal storage device for heating is lower than that of using a heat pump device. In this case, supplementary heating can be provided by the second thermal storage device, with the heat pump device serving as the target heating device and the second thermal storage device as a temporary supplementary heating device. Conversely, when the real-time electricity price is lower than the energy storage electricity price threshold, supplementary heating cannot be provided by the second thermal storage device, and it can be determined whether a heat pump device can be used to store heat for the second thermal storage device.

[0051] Furthermore, when supplementing heat supply through the second heat storage device, the decision to shut down or reduce the heat pump load can be determined based on the heat storage status of the second heat storage device. Specifically, if the heat storage status of the second heat storage device can meet the user load, the heat pump device is shut down; if the heat storage status of the second heat storage device is that it stores heat but cannot meet the user load, the heat pump load is reduced. Then, during the process of supplementing the heat pump device's supply to the user side through the second heat storage device, the heat storage status of the second heat storage device is monitored in real time, and the heat pump device is adjusted according to the heat storage status (such as increasing the heat pump load or starting the heat pump device) to ensure the continuity and stability of heating supply.

[0052] For example: Suppose the heat storage state of the second heat storage device is the outlet water temperature of the second heat storage device, and the lower limit of the outlet water temperature of the second heat storage device is 45°. Then, after the second heat storage device is started, while adjusting the heat pump device according to the heat storage state of the second heat storage device, the outlet water temperature of the second heat storage device will be compared with 45°. When the outlet water temperature of the second heat storage device reaches 45°, the second heat storage device will be stopped from supplying the user side, and the heat exchange device will be used alone to supply the user side.

[0053] In one embodiment, when the target heating device is a gas-fired device, controlling the target heating device to supply heat specifically includes: Start the gas appliance and disconnect the second heat storage device from the water supply pipeline; The flue gas generated by the control gas device is discharged after passing through the first heat storage device, so that the first heat storage device stores the waste heat carried by the flue gas.

[0054] Specifically, when using a gas-fired heating system, the gas-fired system directly supplies heated water to the user side to ensure a stable supply of high-temperature hot water. Furthermore, during the gas-fired heating process, the second heat storage device is disconnected from the water supply pipeline. The flue gas generated by the gas-fired system passes through the first heat storage device before being discharged, allowing the first heat storage device to store the waste heat carried by the flue gas. This waste heat is used to preheat the circulating medium in the heat pump system.

[0055] It is understood that when the target heating equipment includes a heat pump device, the heat pump device uses the first heat storage device to preheat the circulating medium flowing into the evaporator in the heat pump device, so as to recover the waste heat of flue gas stored in the first heat storage device. That is, the circulating medium compressed by the compressor will first flow into the first heat storage device, and after being preheated by the waste heat of flue gas stored in the first heat storage device, it will flow into the evaporator. This application stores the waste heat of flue gas generated by the gas furnace in the first heat storage device, and then uses the waste heat of flue gas to preheat the circulating medium to be flowing into the evaporator. By storing the waste heat of flue gas generated during the operation of the gas furnace in the first heat storage device, the waste heat recovery and utilization are decoupled in time, avoiding the waste of waste heat of flue gas and improving energy utilization efficiency.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A dual-heat storage coupled heating system, characterized in that, The aforementioned dual-heat storage coupled heating system specifically includes: Heat pump devices; Gas appliances; The water supply pipeline is connected to both the water supply inlet of the heat pump device and the water supply inlet of the gas device. The first heat storage device is deployed on the medium circulation pipeline of the heat pump device and connected to the gas device; the first heat storage device is used to store the exhaust waste heat generated when the gas device is working, and release the stored exhaust waste heat to the heat pump device when the heat pump device is running. The second heat storage device is connected to the water supply pipeline, so that a portion of the water supplied by the heat pump device flowing into the water supply pipeline is stored in the second heat storage device and then flows back to the heat pump device.

2. The dual-heat storage coupled heating system according to claim 1, characterized in that, The heat pump device includes a compressor, a condenser, a throttle valve, and an evaporator. The compressor, condenser, throttle valve, and evaporator are connected in sequence to form a medium circulation loop. The first heat storage device is deployed on the medium circulation pipeline between the evaporator and the compressor. The exhaust port of the gas device is connected to the first heat storage device through a pipeline, so that the flue gas generated when the gas device is working can be discharged after storing the exhaust waste heat through the first heat storage device.

3. A control method for a dual-heat storage coupled heating system, characterized in that, The control method for controlling the dual thermal storage coupled heating system as described in any one of claims 1-2 specifically includes: Obtain user load, unit cost of heat pump heating, unit cost of gas-fired heating, and unit cost of second thermal storage device heating. With user load as a constraint and minimum heating cost as the objective, target heating equipment is selected in the dual-heat storage coupled heating system based on the unit cost of heat pump heating, gas device heating, and second heat storage device heating. Control the target heating equipment to supply heat.

4. The control method for the dual-heat storage coupled heating system according to claim 3, characterized in that, The selection of target heating equipment in the dual-heat storage coupled heating system, based on the user load constraint and the goal of minimizing heating costs, according to the unit costs of heat pump heating, gas-fired heating, and the second heat storage device, specifically includes: Based on the unit cost of heat pump heating, the unit cost of gas-fired heating, and the unit cost of the second heat storage device, the first heating device with the lowest unit cost is selected in the dual heat storage coupled heating system. If the first heating equipment meets the user's load, then the first heating equipment will be used as the target heating equipment. If the first heating equipment fails to meet the user load, a second heating equipment is selected based on the unit heating cost of other heating equipment besides the first heating equipment, and the first heating equipment and the second heating equipment are used as target heating equipment. If the first and second heating devices fail to meet the user load, then all heating devices in the dual-heat storage coupled heating system will be used as the target heating devices.

5. The control method for the dual thermal storage coupled heating system according to claim 3 or 4, characterized in that, The unit cost of heating provided by the second thermal storage device is 0, or it is calculated based on a preset energy storage electricity price threshold. The process of obtaining the energy storage electricity price threshold specifically includes: To obtain the energy efficiency ratio of the heat pump unit, the gas price, the thermal efficiency of the gas furnace, and the insulation efficiency; The initial energy storage price is determined based on the energy efficiency ratio and the gas price, and the ratio of the initial energy storage price to the thermal efficiency of the gas furnace is multiplied by the insulation efficiency to obtain the energy storage price threshold.

6. The control method for the dual-heat storage coupled heating system according to claim 3, characterized in that, When the target heating equipment is a heat pump device, controlling the heating of the target heating equipment specifically includes: Start the heat pump unit and monitor the real-time electricity price and current heat load; When the real-time electricity price is lower than the preset energy storage electricity price threshold and the current heat load is lower than the preload threshold, the second heat storage device is connected to the water supply pipeline, so that part of the hot water in the water supply pipeline flows through the second heat storage device for heat storage and part of the hot water is supplied to the user. When the real-time electricity price is lower than the preset energy storage electricity price threshold, or when the current heat load is equal to or higher than the preload threshold, the second heat storage device is disconnected from the water supply pipeline, so that all the hot water in the water supply pipeline is supplied to the user.

7. The control method for the dual-heat storage coupled heating system according to claim 6, characterized in that, The preload threshold is determined based on the rated output of the heat pump unit.

8. The control method for the dual-heat storage coupled heating system according to claim 6, characterized in that, When the target heating device is a heat pump, controlling the heating of the target heating device further includes: When the real-time electricity price is equal to or higher than the preset energy storage electricity price threshold, the heat pump device is turned off or the heat pump load of the heat pump device is reduced, and the second heat storage device is connected to the water supply pipeline, and the water is supplied to the user side through the second heat storage device or the second heat storage device and the heat pump device. During the process of supplementing the heat pump device to supply the user side through the second heat storage device, the heat storage status of the second heat storage device is monitored, and the heat pump device is adjusted according to the heat storage status.

9. The control method for the dual-heat storage coupled heating system according to claim 3, characterized in that, When the target heating device is a gas-fired device, controlling the heating supply of the target heating device specifically includes: Start the gas appliance and disconnect the second heat storage device from the water supply pipeline; The flue gas generated by the control gas device is discharged after passing through the first heat storage device, so that the first heat storage device stores the waste heat carried by the flue gas.

10. The control method for a dual-heat storage coupled heating system according to claim 3 or 9, characterized in that, When the target heating equipment includes a heat pump device, during the operation of the heat pump device, the heat pump device uses the first heat storage device to preheat the circulating medium flowing into the evaporator of the heat pump device, so as to recover the waste heat of flue gas stored in the first heat storage device.

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