Coupled heating systems of PVT heat pumps, air source heat pumps and boilers

Abstract

This invention provides a coupled heating system of a PVT heat pump, an air source heat pump, and a boiler, comprising: a first loop consisting of a hot water storage tank and an air source heat pump; a second loop consisting of the hot water storage tank, the PVT heat pump, the boiler, and a heat exchanger, wherein the PVT heat pump and the boiler are connected by a cable; and a third loop consisting of the hot water storage tank, the heat exchanger, and the user. When the PVT heat pump in the second loop is insufficient to absorb energy, the air source heat pump in the first loop supplies heat to the hot water storage tank. The advantages are enhanced system stability and reliability through the complementary operation of multiple heat sources. The coupled system achieves dynamic switching of heat sources through the coordinated work of the PVT heat pump, the air source heat pump, and the boiler. Utilizing the solar power generation and heating characteristics of the PVT heat pump significantly reduces the consumption of fossil fuels, achieving the goal of prioritizing renewable energy utilization. The boiler, as an unrestricted heat source, is only started when necessary, reducing overall operating time and thus reducing carbon emissions, achieving low-carbon operation of the boiler.

Description

Technical Field

[0001] This utility model relates to the field of energy-saving heating, and in particular to a coupled heating system of a PVT heat pump, an air source heat pump and a boiler. Background Technology

[0002] With social development, newly built heating projects typically utilize new energy and renewable energy sources, or a combination of new and renewable energy sources with conventional energy sources. New heating projects prioritize renewable energy heating, promoting the orderly replacement of gas-fired heating facilities. From a corporate investment perspective, purely renewable or new energy heating faces challenges such as high investment costs and low stability and security. However, heating is a vital public service; therefore, boilers coupled with other renewable energy sources have become the preferred option. Furthermore, peak electricity prices are rising further, while off-peak electricity prices are falling further, resulting in a larger peak-valley price difference. Therefore, during peak electricity price periods, green electricity or off-peak electricity is preferred.

[0003] In existing technologies, the coupled heating system of air source heat pumps and gas boilers is a common implementation scheme. For example, Peng Li et al. proposed a parallel coupled system of air source heat pumps and gas boilers in their research and analysis of air source heat pump coupled gas boiler heating systems. This system achieves dynamic adjustment through three operating modes (gas boiler as base load, air source heat pump as base load, and equilibrium point temperature control). Studies show that the equilibrium point temperature control mode is optimal in terms of operating costs and energy-saving benefits, with an investment of approximately 77 yuan / ㎡ and a static payback period of 6.6 years. Yan Zhaoguo et al. further optimized the coupling form of such systems in their design of a high-efficiency coupled heating system of gas boilers and air source heat pumps. They proposed using a two-stage pump coupling method to adapt to different flow requirements. Through a life-cycle cost analysis, they pointed out that the economic efficiency is optimal when the air source heat pump installation ratio is 30%~40%, but the system still faces the problem of heat pump efficiency decline in low-temperature environments. In addition, Fang Yulong et al.'s research on the coupled heating system of gas boiler and air source heat pump in hot summer and cold winter regions showed that the coupled system has the lowest annual cost when the heat pump installed capacity is 40% to 50%, saving 14.1% to 16.9% of the operating cost compared with a single heat source system. However, it is significantly affected by the peak-valley electricity price difference, and the heat pump is less economical during peak hours.

[0004] Another type of technical solution focuses on the coupling of renewable energy with heat pumps. For example, the PV / T coupled heat pump system proposed by Zhou Dongdong et al. in their analysis of the operational characteristics of PV / T coupled heat pump systems simultaneously generates electricity and collects heat through photovoltaic thermal modules (PV / T), combining ground source heat pumps and air source heat pumps to achieve multi-energy complementarity. This system alleviates the problem of ground temperature decline during the non-heating season by storing heat in the soil, but requires the configuration of large-area photovoltaic modules (180m²). 2 (The above) is to maintain stable ground temperature, resulting in a significant increase in initial investment.

[0005] Although the above technical solutions have achieved certain energy-saving and economic benefits, they still have the following shortcomings: 1. Insufficient economic efficiency and policy compatibility: The initial investment of the existing air source heat pump coupled gas boiler system is relatively high, with a total investment of 6.16 million yuan (Research and Analysis of Air Source Heat Pump Coupled Gas Boiler Heating System), and the payback period is relatively long (6-7 years). Moreover, it does not make full use of renewable energy sources such as photovoltaic power generation, and it is difficult to meet the requirements for mandatory application of photovoltaics in new buildings.

[0006] 2. Poor adaptability to low-temperature environments and peak-valley electricity prices: The COP of air source heat pumps drops significantly in low-temperature environments, with the COP in Beijing as low as 1.67 in winter (design of a high-efficiency coupled heating system of gas boiler and air source heat pump). It needs to rely on gas boiler for peak shaving, while the operating cost of heat pumps during peak electricity price periods may be higher than that of gas boilers (experiment and analysis of coupled heating system of gas boiler and air source heat pump in hot summer and cold winter regions). It cannot effectively respond to the current time-of-use electricity price.

[0007] 3. Lack of cross-seasonal thermal storage technology: Existing solutions do not integrate solar thermal resources with cross-seasonal thermal storage technology, resulting in surplus solar energy during the non-heating season being unable to be stored, making it difficult to achieve efficient energy utilization throughout the year.

[0008] In summary, existing technologies fail to effectively integrate gas-fired boilers, air-source heat pumps, and solar thermal and photovoltaic systems, exhibiting significant deficiencies in terms of policy compliance and system sustainability.

[0009] Therefore, how to provide a coupled heating system that integrates the advantages of PVT heat pumps, air source heat pumps, boilers (including gas and electric boilers), and hot water storage tanks has become an urgent problem to be solved. Utility Model Content

[0010] This invention provides a coupled heating system of PVT heat pump, air source heat pump and boiler, which solves the problem that there is no existing technology that can integrate the advantages of gas boiler, air source heat pump and solar thermal and photovoltaic to improve heating efficiency and make efficient use of resources.

[0011] To achieve the above objectives, this utility model provides a coupled heating system of a PVT heat pump, an air source heat pump, and a boiler, comprising: a first circuit consisting of a hot water storage tank and an air source heat pump; a second circuit consisting of the hot water storage tank, the PVT heat pump, the boiler, and a heat exchanger, wherein the PVT heat pump and the boiler are connected by a cable; a third circuit consisting of the hot water storage tank, the heat exchanger, and the user; when the PVT heat pump in the second circuit is insufficient to absorb energy, the air source heat pump in the first circuit and / or the boiler in the second circuit supply heat to the hot water storage tank.

[0012] As a preferred embodiment of the above technical solution, preferably, a first one-way valve is provided on the pipeline from the hot water storage tank to the air source heat pump in the first circuit.

[0013] As a preferred embodiment of the above technical solution, preferably, a first bidirectional valve is provided on the pipeline from the hot water storage tank to the PVT heat pump in the second circuit.

[0014] As a preferred embodiment of the above technical solution, a second bidirectional valve is provided on the pipeline from the boiler to the heat exchanger in the second circuit.

[0015] As a preferred embodiment of the above technical solution, a second one-way valve is provided on the pipeline in the third circuit that switches to the user direction.

[0016] As a preferred embodiment of the above technical solution, when the ambient temperature of the air source heat pump is higher than the temperature of the hot water storage tank, and the temperature of the PVT heat pump is lower than or equal to the temperature of the hot water storage tank, the first one-way valve opens, the first two-way valve on the pipeline from the hot water storage tank to the PVT heat pump in the second circuit closes, and the second two-way valve on the pipeline from the boiler to the heat exchanger in the second circuit opens, so that water flows from the boiler to the heat exchanger.

[0017] As a preferred embodiment of the above technical solution, when the ambient temperature of the PVT heat pump and the ambient temperature of the air source heat pump are both lower than the temperature of the hot water storage tank, the first one-way valve is closed, the second two-way valve is opened, and the first two-way valve is partially opened.

[0018] As a preferred embodiment of the above technical solution, preferably, the power output interface of the PVT heat pump is connected to the power interface of the boiler via the cable.

[0019] This utility model provides a coupled heating system of a PVT heat pump, an air source heat pump, and a boiler, comprising: a first circuit consisting of a hot water storage tank and an air source heat pump; a second circuit consisting of the hot water storage tank, the PVT heat pump, the boiler, and a heat exchanger, wherein the PVT heat pump and the boiler are connected by a cable; a third circuit consisting of the hot water storage tank, the heat exchanger, and the user; when the PVT heat pump in the second circuit is insufficient to absorb energy, the air source heat pump in the first circuit supplies heat to the hot water storage tank.

[0020] The advantages of this invention are enhanced system stability and reliability through complementary operation of multiple heat sources. The coupled system achieves dynamic switching of heat sources through the coordinated operation of the PVT heat pump, air source heat pump 3, and boiler. Utilizing the characteristics of the PVT heat pump in generating and heating electricity through solar energy significantly reduces fossil fuel consumption, achieving the goal of prioritizing renewable energy use. The boiler, as an unrestricted heat source (peak-shaving heat source), only starts when necessary, reducing overall operating time and thus lowering carbon emissions, achieving low-carbon operation of the boiler. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This utility model provides a structural schematic diagram of a coupled heating system of a PVT heat pump, an air source heat pump, and a boiler. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] like Figure 1 As shown, the present invention provides a coupled heating system of a PVT heat pump, an air source heat pump and a boiler, including a hot water storage tank 1, an air source heat pump 3, a PVT heat pump 2, a boiler 5, a plate heat exchanger 6 and a user 7.

[0025] The piping structure of this utility model is described with the hot water storage tank 1 as the center: The hot water storage tank 1 and the air source heat pump 3 form a first circuit, wherein a first one-way valve 8 is provided on the pipeline from the hot water storage tank 1 to the air source heat pump 3.

[0026] The hot water storage tank 1, PVT heat pump 2, boiler 5, and plate heat exchanger 6 form a second circuit. PVT heat pump 2 and boiler 5 are connected by a cable. A first bidirectional valve 7 is installed on the pipe from the hot water storage tank 1 to the PVT heat pump 2 in the second circuit. A second bidirectional valve 9 is installed on the pipe from the boiler 5 to the plate heat exchanger 6 in the second circuit.

[0027] The hot water storage tank 1, the heat exchanger 6, and the user 7 form a third circuit. In this circuit, a second one-way valve 4 is installed on the pipeline from the heat exchanger 6 to the user 7.

[0028] The power output interface of the PVT heat pump 2 is connected to the power interface of the boiler 5 through the cable, and the PVT heat pump 2 supplies power to the boiler 5 as an auxiliary power source.

[0029] For the first loop, when the ambient temperature of the air source heat pump is higher than the temperature of the hot water storage tank 1, and the temperature of the PVT heat pump 2 is lower than or equal to the temperature of the hot water storage tank 1, the second loop starts to provide auxiliary heating. At this time, the first one-way valve opens, the first two-way valve 7 on the pipeline from the hot water storage tank 1 to the PVT heat pump 2 in the second loop closes, and the second two-way valve 9 on the pipeline from the boiler 5 to the heat exchanger 6 in the second loop opens, so that water flows from the boiler 5 to the heat exchanger 6.

[0030] For the first loop, when the ambient temperature of both the PVT heat pump 2 and the air source heat pump 3 is lower than the temperature of the hot water storage tank 1, the first one-way valve is closed, the second two-way valve 9 is opened, the boiler 5 is used for heating, and the first two-way valve 7 is partially opened to prevent the PVT heat pump 2 from being damaged due to low temperature.

[0031] Furthermore, when the PVT heat pump 2 in the second circuit is insufficient to absorb energy, the air source heat pump 3 in the first circuit and / or the boiler 5 in the second circuit can supply heat to the hot water storage tank.

[0032] Among them, the heat exchanger 6 is connected to the hot water storage tank 1, the heat exchanger 6 is connected to the user 7, and the heat exchanger 6 is connected to the boiler 5 through pipes to form a loop. This loop is used to provide the boiler 5 with stored hot water to the hot water storage tank 1 and heat to the user 7 through pipes when neither the air source heat pump nor the PVT heat pump 2 can provide heat.

[0033] The present invention is described below with reference to a specific embodiment. Specifically, boiler 5 serves as a traditional heat source, providing stable heat energy, and acts as an auxiliary heat source during extreme weather or peak system demand. In PVT heat pump 2, the PV section converts solar energy into electrical energy, which can be used for the system's power needs or connected to the power grid. The T section collects solar thermal energy for heating the circulating medium of the heating system. Air source heat pump 3 utilizes the thermal energy in the ambient air for heating, serving as the primary heat source during mild weather or when sunlight is insufficient. Plate heat exchanger 6 is used for heat energy transfer between different heat sources, ensuring efficient transfer of heat energy to the circulating medium of the heating system. Circulation pump is used to drive the circulating medium of the heating system to circulate within the system.

[0034] Specifically, when there is sufficient sunlight: PVT heat pump 2 prioritizes solar energy for heating, the electricity generated by the PV part can be used to drive other equipment in the system, such as boiler (electric boiler) 5, and the remaining heat energy demand can be supplemented by air source heat pump 3.

[0035] Please explain based on the specific circumstances: spring: Springtime typically brings warmer temperatures, with increased sunlight and rising air temperatures. However, the air temperature is usually lower than that of the hot water storage tank 1, resulting in a weaker ability of the PV portion of the PVT heat pump 2 to convert solar energy into electricity (equivalent to the PVT heat pump 2's temperature being lower than or equal to that of the hot water storage tank 1). At this time, the one-way valve in the first loop closes to prevent the air source heat pump 3 from dissipating the heat energy in the hot water storage tank 1. The second two-way valve 9 between the boiler 5 and the plate heat exchanger 6 opens, and the second one-way valve 4 between the user 7 and the plate heat exchanger 6 opens. The boiler 5 supplies heat to the hot water storage tank 1 and the user 7 via the plate heat exchanger 6. The main cycle is: Boiler 5 - Plate Heat Exchanger 6 - Hot Water Storage Tank 1 - Plate Heat Exchanger 6 - User 7 - Plate Heat Exchanger 6 - Boiler 5. Within this main cycle, there can be smaller cycles between the hot water storage tank 1 and the plate heat exchanger 6, and between the plate heat exchanger 6 and the user 7.

[0036] summer: In summer, temperatures typically rise rapidly. Sunlight intensity is high, and air temperature is also high, usually significantly higher than that of the hot water storage tank 1. The PV component of the PVT heat pump 2 has a strong ability to convert solar energy into electrical energy (equivalent to the PVT heat pump 2 being at a higher temperature than the hot water storage tank 1). At this time, the first bidirectional valve 7 opens, the first one-way valve opens, the second one-way valve 4 opens, and the second bidirectional valve 9 is selected to open / close.

[0037] PVT heat pump 2 is used to simultaneously supply heat to the hot water storage tank 1 through solar energy and air heat energy, along with the air source heat pump. The heat is then supplied to the user 7 via plate heat exchanger 6. The PV part of PVT heat pump 2 converts solar energy into electrical energy to supply power to boiler 5. The second two-way valve 9 is closed, and boiler 5 stores the electrical energy generated by solar energy for use in cold weather.

[0038] autumn: Autumn typically sees a slow decrease in temperature, with reduced sunlight intensity but high air temperature, usually significantly higher than that of the hot water storage tank 1. The T section of the PVT heat pump 2 collects as much solar thermal energy as possible as an auxiliary heat source for the hot water storage tank 1. At this time, the first bidirectional valve 7 opens periodically (e.g., during periods of strong sunlight like midday), the first one-way valve opens, and the second one-way valve 4 opens. Depending on the actual needs of autumn, the second bidirectional valve 9 is opened to supply heat to user 7 or closed directly. The boiler 5 continues to store the electrical energy converted by the PV section of the PVT heat pump 2 for use during cold weather.

[0039] winter: In winter, the air temperature is low and sunlight is weak, with the air temperature significantly lower than that of the hot water storage tank 1. At this time, the T section of the PVT heat pump 2 collects solar thermal energy to maintain its operation. The opening of the first bidirectional valve 7 allows the hot water storage tank 1 to supply heat to the PVT heat pump 2 to maintain its normal operation and prevent freezing. The first one-way valve opens intermittently to ensure smooth water flow in the pipeline of the first loop formed by the hot water storage tank 1 and the air source heat pump 3. The second bidirectional valve 9 is normally open, and the boiler 5, as the main heat source, supplies heat to the hot water storage tank 1 and the user 7 via the plate heat exchanger 6. At this time, the boiler 5 utilizes stored solar power.

[0040] In summary, the system provided by this invention uses the air source heat pump 3 as the main heat source for heating when sunlight is insufficient, while the T section of the PVT heat pump 2 still collects solar thermal energy as an auxiliary heat source. During extreme weather or peak system demand, the boiler 5 starts up to provide a stable supplementary heat energy. The control system intelligently schedules the output ratio of each heat source to meet heating needs and optimize energy consumption.

[0041] This system can also be configured with a control system to monitor and control the operation of the entire heating system. Based on factors such as outside temperature, sunlight conditions, and heating demand, it intelligently adjusts the output ratio of each heat source.

[0042] The boiler 5, PVT heat pump 2 (photovoltaic-thermal combined system) and air source heat pump 3 coupled heating system is a high-efficiency heating solution that combines the advantages of multiple heat sources to improve heating efficiency and energy utilization.

[0043] The technical solution provided by this utility model can improve the system's energy efficiency and energy utilization rate through the synergistic utilization of solar energy by the PVT heat pump 2, and optimize the low-temperature adaptability of the air source heat pump 3. This is because in this technical solution, the PVT heat pump 2 or boiler 5 can serve as an auxiliary heat source, intervening in heating at extremely low temperatures, solving the problems of frosting and energy efficiency reduction that easily occur in the air source heat pump 3 under low-temperature environments, and compensating for the insufficient heating capacity of the air source heat pump 3. The functions of boiler 5 are enriched, enabling it to have peak-shaving and backup functions. As a peak-shaving heat source, boiler 5 can quickly start to supplement heat when the PVT heat pump 2 or air source heat pump 3 cannot meet the demand (such as continuous rainy days or extremely cold weather). This design avoids the limitations of a single heat source and improves the overall energy efficiency of the system.

[0044] Among them, the model of PVT heat pump 2 can be PVT-6K6P2197L.

[0045] The technical solution provided by this utility model enhances system stability and reliability through the complementary operation of multiple heat sources. The coupled system achieves dynamic switching of heat sources through the coordinated operation of PVT heat pump 2, air source heat pump 3, and boiler 5. For example, PVT heat pump 2 is prioritized during the day when there is sufficient sunlight, while switching to air source heat pump 3 or boiler 5 at night or on cloudy days ensures continuous heating. Utilizing the solar power generation and heating characteristics of PVT heat pump 2 significantly reduces fossil fuel consumption, achieving the goal of prioritizing renewable energy use. Boiler 5, as an unrestricted heat source (peak-shaving heat source), is only started when necessary, reducing overall operating time and thus reducing carbon emissions, achieving low-carbon operation of boiler 5. By prioritizing the use of solar and air energy, the consumption of gas and electricity is reduced, lowering operating costs. The coordinated operation of multiple heat sources reduces the long-term high-load operation of individual equipment, extending equipment lifespan. For example, air source heat pump 3 avoids frequent start-stop operations under extreme low temperatures in the coupled system, reducing the failure rate.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A coupled heating system of a PVT heat pump, an air source heat pump, and a boiler, characterized in that, include: The hot water storage tank and the air source heat pump form the first circuit; The hot water storage tank, PVT heat pump, boiler and plate heat exchanger form a second circuit, wherein the PVT heat pump and the boiler are connected by a cable; The hot water storage tank, the heat exchanger, and the user form a third circuit; When the PVT heat pump in the second circuit is insufficient to absorb energy, the air source heat pump in the first circuit and / or the boiler in the second circuit supply heat to the hot water storage tank.

2. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 1, characterized in that, A first one-way valve is installed on the pipeline from the hot water storage tank to the air source heat pump in the first circuit.

3. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 2, characterized in that, A first bidirectional valve is installed on the pipeline from the hot water storage tank to the PVT heat pump in the second circuit.

4. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 3, characterized in that, A second bidirectional valve is installed on the pipeline from the boiler to the heat exchanger in the second circuit.

5. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 1, characterized in that, A second one-way valve is installed on the pipeline in the third circuit that switches the plate to the user direction.

6. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 4, characterized in that, When the ambient temperature of the air source heat pump is higher than the temperature of the hot water storage tank, and the temperature of the PVT heat pump is lower than or equal to the temperature of the hot water storage tank, the first one-way valve opens, the first two-way valve on the pipeline from the hot water storage tank to the PVT heat pump in the second circuit closes, and the second two-way valve on the pipeline from the boiler to the heat exchanger in the second circuit opens, so that water flows from the boiler to the heat exchanger.

7. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 4, characterized in that, When the ambient temperature of the PVT heat pump and the ambient temperature of the air source heat pump are both lower than the temperature of the hot water storage tank, the first one-way valve is closed, the second two-way valve is opened, and the first two-way valve is partially opened.

8. The coupled heating system of PVT heat pump, air source heat pump and boiler according to claim 1, characterized in that, The power output interface of the PVT heat pump is connected to the power interface of the boiler via the cable.

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