Combined type air source heat pump air conditioning system

Abstract

The invention relates to a combined type air source heat pump air conditioning system which comprises an air source heat pump, an energy storage module, a user module, a control module and a flow path switching module. The air source heat pump communicates with the energy storage module through the flow path switching module, and the energy storage module communicates with the user module through the flow path switching module. The air source heat pump comprises a standard unit, a low-temperature unit and a photo-thermal unit; the air source heat pump units are arranged in parallel and electrically connected through the intelligent control module, and the intelligent control module is further electrically connected with the energy storage module, the user module and the flow path switching module. The intelligent control module automatically switches working modes according to the external environment temperature. Through intelligent control and cooperative work of multiple units, the higher energy efficiency ratio (COP) is achieved, and the operation cost is reduced. All the units are independently designed but complement each other, and reliability is high.

Description

Technical Field

[0001] The invention relates to the technical field of renewable energy, in particular to a composite air source heat pump air conditioning system. Background Art

[0002] Traditional air source heat pumps are inefficient in cold climates, especially in extremely low temperature environments, and are difficult to operate stably. Solar thermal units and heat pumps are independent systems, resulting in heat exchange losses of more than 15%. In addition, a single type of air source heat pump cannot fully adapt to changes in different seasons or environmental conditions, resulting in low energy efficiency. The adaptability to low temperatures is poor, and the COP value of traditional air source heat pumps drops significantly below 10°C. At extremely low temperatures, they need to rely on electric auxiliary heating, which increases energy consumption; the energy utilization is single, and a single heat pump cannot take into account the needs of different seasons. For example, the efficiency of solar heat pumps drops sharply on rainy days; the system redundancy is insufficient, and existing composite systems mostly use a series structure, and a single point failure can easily lead to system paralysis. Summary of the invention

[0003] The purpose of the present invention is to provide a composite air source heat pump air conditioning system, which is a composite system integrating a standard air source heat pump, a low-temperature air source heat pump and a solar thermal air source heat pump, and realizes efficient and stable heating and cooling under all climate conditions through multi-unit collaborative control and energy dynamic optimization technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The composite air source heat pump air conditioning system includes an air source heat pump, an energy storage module, a user module, a control module and a flow path switching module; the air source heat pump is connected to the energy storage module through the flow path switching module, and the energy storage module is connected to the user module through the flow path switching module; the air source heat pump includes a standard unit, a low temperature unit and a solar thermal unit; each air source heat pump unit is arranged in parallel and electrically connected through an intelligent control module, and the intelligent control module is also electrically connected to the energy storage module, the user module and the flow path switching module respectively; the intelligent control module automatically switches the working mode according to the external ambient temperature, and the control method includes: when the ambient temperature is ≥10°C, the standard unit + solar thermal unit combination mode is adopted for operation, and the energy storage module is charged to ≤80% SOC during the day; when the ambient temperature is between 10°C and -10°C, the low temperature unit + solar thermal unit is operated in parallel, and the energy storage module dynamically releases energy according to the load demand; when the ambient temperature is less than -10°C, the low temperature unit + electric auxiliary heating + energy storage combination mode is adopted for operation, and the energy storage module is forced to release energy to SOC ≥20%;

[0006] The energy storage module charging / discharging rate Q rate Through fuzzy PID algorithm control, the formula is:

[0007]

[0008] Among them, e(t) is the difference between the set temperature and the actual temperature, and the control coefficient K p =0.8,K i =0.05,K d =0.1.

[0009] In the above-mentioned composite air source heat pump air conditioning system, the low-temperature unit includes a jet reheat compressor and a stainless steel cold-resistant fin evaporator, and a PTC electric heating tape is laid on the surface of the evaporator.

[0010] In the above-mentioned composite air source heat pump air conditioning system, the energy storage module is a phase change material energy storage device or a water tank heat storage device, and the phase change material of the energy storage module is a carboxylic acid mixture, the phase change temperature is 45±2°C, and the latent heat value is ≥220kJ / kg.

[0011] In the above-mentioned composite air source heat pump air conditioning system, the solar thermal unit includes an external fin tube and an internal refrigerant tube; the surface of the external fin tube is coated with a TiAlN solar selective absorption coating, and the internal refrigerant tube is a microchannel flat tube; the microchannel flat tube is connected to the external fin by brazing.

[0012] In the above-mentioned composite air source heat pump air-conditioning system, the flow switching module includes a three-way proportional regulating valve, which is used to control the flow direction of the refrigerant; the refrigerant pipelines of the standard unit, the low-temperature unit and the solar thermal unit are independently connected and physically isolated through the three-way valve.

[0013] The beneficial effects of the present invention are:

[0014] The present invention can operate stably in a wide temperature range, and is particularly suitable for the geographical characteristics of my country with a large temperature difference between the north and the south, and has strong adaptability. It makes full use of natural energy, reduces dependence on traditional fossil fuels, reduces carbon emissions, and saves energy and protects the environment. Through intelligent control and the coordinated operation of multiple units, a higher energy efficiency ratio (COP) is achieved, and operating costs are reduced. Each unit is designed independently but complements each other. Even if a component fails, it will not affect the normal operation of the entire system, and the reliability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structural principle of the present invention;

[0016] In the figure: 1 - standard unit; 2 - low temperature unit; 3 - solar thermal unit; 4 - energy storage module; 5 - user module; 7 - flow switching module; 6 - intelligent control module. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] refer to Figure 1 The present invention provides a full-climate adaptive composite air source heat pump system, including an air source heat pump, an energy storage module 4, a user module 5, a control module 6 and a flow path switching module 7; the air source heat pump is connected to the energy storage module 4 through the flow path switching module 7, and the energy storage module 4 is connected to the user module 5 through the flow path switching module 7; the air source heat pump includes three main parts: a standard unit 1, a low temperature unit 2 and a solar thermal unit 3. Each air source heat pump unit is arranged in parallel and electrically connected through an intelligent control module 6, and the intelligent control module 6 is also electrically connected to the energy storage module 4, the user module 5 and the flow path switching module 7 respectively; the intelligent control module 6 automatically switches the working mode according to the external environment temperature.

[0019] The intelligent control module 6 realizes the automatic management and coordinated control of the three types of units, and selects the most appropriate operation mode according to the real-time meteorological data. It has the remote monitoring function, and the user can check the system status and adjust it at any time through the terminal devices such as mobile phone APP. The intelligent control module 6 includes a meteorological sensing unit and a central controller. The meteorological sensing unit integrates dry-bulb temperature sensor, irradiance sensor (accuracy ±5W / m 2 ), wind speed sensor; the central controller is equipped with a multi-objective optimization algorithm to calculate the expected COP value of each unit in real time.

[0020] The control method of the cooperative working mode of the intelligent control module 6 of the present invention is:

[0021] When the ambient temperature is ≥10℃, the standard unit + solar thermal unit combination mode is adopted for operation, and the energy storage module 4 is charged to 80% SOC during the day; when the ambient temperature is between 10℃ and -10℃, the low-temperature unit + solar thermal unit is operated in parallel, and the energy storage module 4 releases energy dynamically according to the load demand; when the ambient temperature is less than -10℃, the low-temperature unit + electric auxiliary heating + energy storage combination mode is adopted for operation, and the energy storage module 4 is forced to release energy to SOC ≥20%

[0022] Standard unit 1 uses a dual-rotor variable frequency compressor with an applicable temperature range of 5℃~45℃; it is suitable for medium and high temperature conditions and is usually used for cooling needs in spring, autumn and summer. It is equipped with a high-efficiency compressor and heat exchanger to ensure stable heat output to user module 5 within a relatively suitable temperature range.

[0023] Low temperature unit 2 is equipped with a jet reheat compressor and a cold-resistant fin evaporator made of 310S stainless steel. The surface of the evaporator is covered with a PTC electric heating cable with a power density of 25W / m, which automatically starts and stops according to the frost sensor signal; the defrost cycle adopts temperature difference and time dual parameter control: defrost is triggered when the temperature difference between the inlet and outlet of the evaporator is ≥8℃ or the cumulative running time is ≥60min. The applicable temperature range of low temperature unit 2 is 30℃~10℃; it is specially optimized for the low temperature environment in winter, and uses cold-resistant materials and technical means to ensure that it can still operate effectively below -25℃. It has a built-in electric auxiliary heating device to assist heating under extreme low temperature conditions to ensure that the heating effect is not affected.

[0024] Solar thermal unit 3 integrates a dual-channel fin heat exchanger, including an external fin tube and an internal refrigerant tube. The surface of the external fin tube is coated with a TiAlN solar selective absorption coating with an absorption rate of ≥93% and a thickness of 80-100μm; the internal refrigerant tube adopts a microchannel flat tube with a cross-sectional size of 1.8mm×16mm, which is connected to the external fin by brazing; combined with solar collector panels and air source heat pump technology, solar radiation energy is used to preheat the air during the day to reduce the demand for compressor cooling / heating. The solar collector panel can be tilted to adjust the angle to maximize the reception of sunlight, and can maintain a certain working efficiency even on cloudy days.

[0025] The flow path switching module 7 includes a three-way proportional regulating valve and an electronic expansion valve. The three-way proportional regulating valve controls the flow direction of the refrigerant, and the valve body has a pressure resistance of ≥4.2MPa; the opening accuracy of the electronic expansion valve is ±5%, and the response time is ≤2s. The refrigerant pipelines of the standard unit, low-temperature unit and solar thermal unit are independent and physically isolated by a three-way valve; when a single unit fails, the remaining units can automatically compensate for at least 70% of the rated power.

[0026] Energy storage module 4 uses phase change material energy storage and water tank heat storage device to store excess energy, and release it when needed to further balance the supply and demand relationship. Energy storage module 4 includes a phase change energy storage tank and a plate heat exchanger. The phase change energy storage tank contains carboxylic acid phase change material (phase change temperature 45±2℃, latent heat value ≥220kJ / kg); the heat exchange area of ​​the plate heat exchanger is designed to be 1:1.5 with the total power of the unit.

[0027] The charging / discharging rate of the energy storage module 4 is controlled by a fuzzy PID algorithm, and the formula is:

[0028]

[0029] Among them, e(t) is the difference between the set temperature and the actual temperature, and the control coefficient K p =0.8,K i =0.05,K d =0.1, and the values ​​of each coefficient are obtained through experience.

[0030] The present invention achieves the technical goal of an average annual COP ≥ 3.5 and COP ≥ 2.0 under extremely low temperatures through the parallel coordination of multiple units, photothermal efficiency enhancement and intelligent energy storage technology. In practical applications, the proportion of each unit can be flexibly configured according to the climate characteristics of different regions and the specific needs of users. For example, in the cold northern regions, the number of low-temperature air source heat pump units can be appropriately increased; while in the warm and humid environment in the south, more emphasis is placed on the application of standard air source heat pump units and photothermal air source heat pump units. In addition, for large public buildings or industrial facilities, it is also possible to consider integrating larger-scale energy storage units to meet the additional load requirements during peak hours.

[0031] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A composite air source heat pump air conditioning system, characterized in that: The invention comprises an air source heat pump, an energy storage module (4), a user module (5), a control module (6) and a flow path switching module (7); the air source heat pump is connected to the energy storage module (4) through the flow path switching module (7), and the energy storage module (4) is connected to the user module (5) through the flow path switching module (7); the air source heat pump comprises a standard unit (1), a low temperature unit (2) and a solar thermal unit (3); each air source heat pump unit is arranged in parallel and is electrically connected through an intelligent control module (6), and the intelligent control module (6) is also electrically connected to the energy storage module (4), the user module (5) and the flow path switching module respectively. (7); The intelligent control module (6) automatically switches the working mode according to the external ambient temperature, and the control method includes: when the ambient temperature is ≥10°C, the standard unit + solar thermal unit combination mode is adopted for operation, and the energy storage module (4) is charged to ≤80% SOC during the day; when the ambient temperature is between 10°C and -10°C, the low-temperature unit + solar thermal unit is adopted for operation in parallel, and the energy storage module (4) dynamically releases energy according to the load demand; when the ambient temperature is less than -10°C, the low-temperature unit + electric auxiliary heating + energy storage combination mode is adopted for operation, and the energy storage module (4) is forced to release energy to SOC ≥20%; The energy storage module (4) has a charge / discharge rate Q rate Through fuzzy PID algorithm control, the formula is: Among them, e(t) is the difference between the set temperature and the actual temperature, and the control coefficient K p =0.8,K i =0.05,K d =0.

1.

2. The composite air source heat pump air conditioning system according to claim 1, characterized in that: The low-temperature unit (2) comprises a jet heat-increasing compressor and a stainless steel cold-resistant fin evaporator, and a PTC electric heating tape is laid on the surface of the evaporator.

3. The composite air source heat pump air conditioning system according to claim 1, characterized in that: The energy storage module (4) is a phase change material energy storage device or a water tank heat storage device. The phase change material of the energy storage module (4) is a carboxylic acid mixture, with a phase change temperature of 45±2° C. and a latent heat value of ≥220 kJ / kg.

4. The composite air source heat pump air conditioning system according to claim 1, characterized in that: The solar thermal unit (3) comprises an external fin tube and an internal refrigerant tube; the surface of the external fin tube is coated with a TiAlN solar selective absorption coating, and the internal refrigerant tube is a microchannel flat tube; the microchannel flat tube is connected to the external fin by brazing.

5. The composite air source heat pump air conditioning system according to claim 1, characterized in that: The flow path switching module (7) comprises a three-way proportional regulating valve, which is used to control the flow direction of the refrigerant; the refrigerant pipelines of the standard unit (1), the low-temperature unit (2) and the solar thermal unit (3) are independently connected and physically isolated through the three-way valve.

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