CN114674027A - Solar energy and low-temperature air source heat pump auxiliary type phase change heat storage and supply system and method - Google Patents

Abstract

The invention belongs to the technical field of heat storage and heat supply, and specifically discloses an air source and solar energy-assisted heat storage and heat supply system, comprising: a solar heat collector connected by pipelines, a solar/air dual-source heat pump unit, and a hot water storage system. Tank and user end; solar collectors are used to absorb solar energy to heat the circulating medium; solar/air dual source heat pump units are used to exchange heat in the low temperature air to the hot water storage tank with the assistance of the connected heated circulating medium In the circulating medium in the hot water storage tank, or only the heat in the low-temperature air is exchanged to the circulating medium in the hot water storage tank; the user end is used for heating the user by using the heat of the circulating medium in the hot water storage tank; also includes circulation Selection mechanism; the invention also discloses a corresponding heating method, which solves the technical problem that a single solar heating system cannot provide a stable and reliable heat source for the room.

Description

A solar energy and low temperature air source heat pump assisted phase change heat storage heating system and method

technical field

The invention belongs to the technical field of heat storage and heat supply, and particularly relates to an air source and solar energy-assisted heat storage and heat supply system and method.

Background technique

The traditional distributed heating system uses fossil fuels as the main energy supply method, which has problems such as poor economy and environmental pollution. On the other hand, heating methods such as heat pumps and air conditioners have problems such as high operating costs and increased pressure during peak hours of the power grid.

As a renewable energy, solar energy has the obvious advantages of green environmental protection, energy saving and economy, and has become the energy with the most development potential at present, and the plateau area has abundant solar energy resources that can be utilized. Due to the instability of solar energy, only using solar energy for heating will lead to an increase in the number of days where the room temperature is not satisfactory. In addition, the solar heating system cannot heat the room at night, and the solar heating is also affected by the weather, such as cloudy days, etc., so that a single solar heating system cannot provide a stable and reliable heat source for the room.

SUMMARY OF THE INVENTION

The present invention intends to propose a phase-change heat storage heating system assisted by solar energy and low temperature air source heat pump, which maximizes the utilization of solar energy, supplements the air source heat pump as the second heat source, and adopts enhanced heat exchange type convection-radiation at the user end. The combined phase-change heat storage floor is used to provide heat at night to solve the technical problem that a single solar heating system cannot provide a stable and reliable heat source for the interior.

For achieving the above object, the technical scheme adopted in the present invention is:

A solar energy and low temperature air source heat pump assisted phase change heat storage heating system, comprising:

Solar collectors, solar/air dual-source heat pump units, hot water storage tanks and user terminals connected by pipelines;

The solar collector is used for absorbing solar energy to heat the circulating medium;

The solar/air dual source heat pump unit is used to exchange the heat in the low temperature air to the circulating medium in the hot water storage tank with the assistance of the connected heated circulating medium, or only exchange the heat in the low temperature air into the circulating medium in the hot water storage tank;

The user terminal is used for heating the user by using the heat of the circulating medium in the hot water storage tank;

It also includes a cycle selection mechanism for selecting the cycle of the circulating medium and opening and closing the solar/air dual-source heat pump unit according to the following strategies:

When the temperature of the circulating medium is higher than the first temperature threshold, the circulating medium only circulates between the solar collector and the hot water storage tank through the pipeline, and the solar/air dual-source heat pump unit does not work;

When the temperature of the circulating medium is lower than the first temperature threshold but higher than the second temperature threshold, the circulating medium passes through the pipeline in parallel between the solar collector and the hot water storage tank, the solar thermal collector and the hot water storage tank solar/air Circulation between dual-source heat pump units, solar/air dual-source heat pump units work;

When the temperature of the circulating medium is lower than the second temperature threshold, the circulating medium stops circulating, and only the solar/air dual-source heat pump unit works.

Further, the cycle selection mechanism includes a first temperature sensor and a first electric three-way valve arranged on the pipeline of the water outlet of the solar collector according to the order of water flow; the first electric three-way valve divides the pipeline into two parts. It is two-way, one is connected to the hot water storage tank, and the other is connected to the solar/air dual-source heat pump unit;

It also includes a first circulating water pump 9 arranged on the pipeline between the first electric three-way valve and the hot water storage tank, and a second electric water pump 9 arranged on the pipeline returning from the solar/air dual-source heat pump unit to the solar collector. Three-way valve; the second electric three-way valve is also on the pipeline from the self-storage hot water tank back to the solar collector;

and a controller for opening and closing and switching the circulation path of the circulating medium and opening and closing the circulating medium by opening and closing the corresponding circulating water pump and gating the corresponding electric three-way valve according to the temperature sensed by the first temperature sensor and according to the aforementioned strategy. Closed solar/air dual source heat pump unit.

Further, the first temperature threshold is 28-31°C, and the second temperature threshold is 25-28°C.

Further, the user end includes a phase change material thermal storage floor heating terminal device, which is used to store the heat from the circulating medium in the hot water storage tank by utilizing the thermal storage properties of the phase change material, and convert the heat through radiation and convection. Heat is supplied to the user.

Further, the phase change temperature of the phase change material in the thermal storage floor heating terminal device of the phase change material is 27.99°C-30.99°C.

Further, the phase change material thermal storage floor heating terminal device is in the shape of a floor, and includes a ground layer, a load-bearing structure layer, an air layer, a moisture-proof layer, a phase change material layer and a thermal insulation layer in order from top to bottom;

The ground layer and the load-bearing structure layer are provided with heat exchange holes;

A ground coil pipe is laid in the change material layer, and a deformation joint is set in the phase change material between the adjacent two ground coil pipes;

The ground pipe is connected to the hot water storage tank.

Further, the phase change material of the phase change material layer is a microcapsule phase change material with n-octadecane as the core material and titanium dioxide-polyurea as the wall material, the phase change temperature is 29.66°C, and the latent heat of phase change is 181.1J/g.

Further, the evaporator in the solar/air dual-source heat pump unit is a dual-source evaporator, including an outer shell and an inner tube located in the outer shell;

The inner tube can pass the circulating medium, the outer shell can be in contact with the low-temperature air, and the refrigerant can pass between the outer shell and the inner tube; and the refrigerant can exchange heat with the circulating medium and the low-temperature air through the outer shell and the inner tube.

The present invention also provides a solar energy and low-temperature air source heat pump-assisted phase-change heat storage heat supply method, comprising:

Absorb solar energy with solar collectors to heat the circulating medium;

Using a solar/air dual-source heat pump unit, the heat in the low-temperature air is exchanged to the circulating medium in the hot water storage tank with the assistance of the connected heated circulating medium, or only the heat in the low-temperature air is exchanged to the storage tank. In the circulating medium in the hot water tank;

When the temperature of the circulating medium output by the solar collector is higher than the first temperature threshold, the circulating medium only circulates between the solar collector and the hot water storage tank through the pipeline, and the solar/air dual-source heat pump unit does not work;

When the temperature of the circulating medium output by the solar collector is lower than the first temperature threshold but higher than the second temperature threshold, the circulating medium passes through the pipeline in parallel between the solar collector and the water storage tank, the solar collector and the storage tank. The hot water tank solar/air dual-source heat pump unit circulates, and the solar/air dual-source heat pump unit works;

When the temperature of the circulating medium output by the solar collector is lower than the second temperature threshold, the circulating medium stops circulating, and only the solar/air dual-source heat pump unit works;

Through the user end, the heat of the circulating medium in the hot water storage tank is used to heat the user, and the heat from the circulating medium in the hot water storage tank is heated by the heat storage property of the phase change material deployed on the floor side of the user end. It is stored, and heat is supplied to users through radiation and convection heat exchange.

Further, it also includes dividing the whole day into unfavorable time periods, suitable time periods and favorable time periods;

The unfavorable period is the period of the day when the dry bulb temperature is the lowest;

The favorable period is the period of the day when the dry bulb temperature is the highest;

other time periods are suitable time periods;

Use solar collectors and/or solar/air dual-source heat pump units to collect heat during favorable periods, and use hot water storage tanks and phase-change heat storage floors to store heat;

During unfavorable times, the heat storage of the hot water storage tank and the phase change heat storage floor is used to provide heat for the user.

The beneficial effects of the present invention are:

In the present invention, the temperature of the circulating medium output by the solar collector is used to judge the current solar radiation intensity and switch the working mode. When the solar radiation intensity is sufficient to meet the indoor heating demand (the temperature of the output circulating medium is greater than the first A threshold value), use the solar collector for heating and heating alone; when the temperature of the circulating medium can be heated to a certain temperature with the intensity of sunlight, but it is not enough to meet the indoor heating demand (the temperature of the output circulating medium is less than the first threshold value and greater than The second threshold) and the solar/air dual-source heat pump unit are coupled for heating and heating; when the solar/air dual-source heat pump unit only works as a low-temperature air source heat pump system for heating and heating alone, the system always uses the most efficient heat conversion mode , under the premise of ensuring the user's heating experience, maximize the use of renewable energy and reduce its own energy consumption.

In the present invention, the use of phase change materials greatly increases the thermal inertia of the room. The heat storage is 6-7h every day, which can meet the design requirements of the room temperature for 24 hours, and the thermal inertia effect is remarkable, which can reduce the heating demand for the next day.

The present invention can store solar heat or air heat in favorable periods (such as daytime) for use in unfavorable periods such as nighttime heating, thereby improving the utilization rate of renewable energy and saving energy to the greatest extent.

Description of drawings

FIG. 1 is a schematic diagram of a solar energy and low temperature air source heat pump assisted phase change heat storage heating system in an embodiment of the present invention.

FIG. 2 is a front view of the solar heat collector in the embodiment of the present invention.

FIG. 3 is a left side view of the solar thermal collector in FIG. 2 .

4 is a schematic structural diagram of a solar ray tracer device of the present invention in an embodiment of the present invention, in which part (a) is a left side view and a partial enlarged view thereof, (b) part is a right side view, and (c) part is a right side view.

FIG. 5 is a schematic diagram of a longitudinal cross-sectional structure of a convection-radiation combined phase-change heat storage floor in an embodiment of the present invention.

FIG. 6 is a schematic diagram of the work flow of the solar energy and low temperature air source heat pump assisted phase change heat storage heating system in the embodiment of the present invention.

The reference signs in the accompanying drawings include: 1—solar heat collector, 2—first temperature sensor, 3—first electric three-way valve, 4—fan, 5—dual source evaporator, 6—first valve, 7—gas-liquid separator, 8—compressor, 9—first circulating water pump, 10—first check valve, 11—second valve, 12—air source heat pump heat exchanger, 13—liquid accumulator, 14— Filter, 15—thermal expansion valve, 16—second circulating water pump, 17—second temperature sensor, 18—hot water storage tank, 19—third valve, 20—second check valve, 21—first electric valve , 22—second electric three-way valve, 23—fourth temperature sensor, 24—fourth valve, 25—third check valve, 26—first pressure sensor, 27—phase change material heat storage floor, 28—fan Coil convection heat transfer end, 29—helix heater, 30—second pressure sensor, 31—third circulating water pump, 32—third pressure sensor, 33—fourth check valve, 34—fifth temperature sensor, 35—The second electric valve. 36-edge and corner insulation material; 37-heat exchange hole; 38-deformation joint; 39-load-bearing structure; 40-ground layer; 41-air layer; 42-moisture-proof layer; 43-phase change material layer; 44-insulation layer; 45-ground coil; 46-ray tracing device; 47-horizontal shaft; 48-solar heat collector plate; 49-balance rod; 50-horizontal motor; 51-tilt motor; 52-horizontal transmission gear; 53-tilt drive Gear; 54-semi-circular adjustment gear; 55-filter; 56-photoresistor; 60-rocker arm; 61-fixed arm; 62-tilt shaft; 63-semicircle base

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

As shown in FIG. 1, a solar energy and low-temperature air source heat pump-assisted phase-change heat storage heating system in this embodiment includes a solar collector 1, a solar/air dual-source heat pump unit, a hot water storage tank 18, Phase change material heat storage floor heating terminal device 27 and fan coil unit convection heat exchange terminal device 28;

The solar/air source heat pump unit includes a dual source evaporator 5, an air source heat pump heat exchanger 12 and a coil heater 29

In addition, the system also includes connecting pipelines, multiple groups of circulating water pumps and multiple groups of valves;

The solar collector 1 is used to collect solar energy to heat water, and the pipeline at the water outlet is provided with a first temperature sensor 2 and a first electric three-way valve in order of water flow; the pipeline from the first electric three-way valve is divided into two parts. It is two-way, one is connected to the hot water storage tank 18, and the first circulating water pump 9, the first check valve 10, and the second valve 11 are arranged on this pipeline in sequence according to the order of water flow; the other pipeline is connected to the dual source Evaporator 5, so that the hot water heated by the solar collector 1 can enter the inner pipe of the dual-source evaporator 5, the outer surface of the dual-source evaporator 5 is equipped with a fan 4, and the dual-source evaporator 5 can circulate three media for Heat exchange, that is, the refrigerant exchanges heat with the solar hot water flowing through the inner tube and the air flowing through the outer surface at the same time, and then the refrigerant flowing out from the dual-source evaporator 5 flows into the air source heat pump heat exchanger 12 through the pipeline, This part of the pipeline is provided with a gas-liquid separator 7 and a compressor 8 in sequence according to the direction of refrigerant flow; the refrigerant that has completed heat exchange in the air source heat pump heat exchanger 12 is returned to the dual-source evaporator 5 through the pipeline , on this part of the pipeline, the accumulator 13, the filter 14 and the thermal expansion valve 15 are arranged in sequence according to the direction of the refrigerant flow.

When the hot water from the solar collector 1 is not passed through the inner pipe of the double-source evaporator 5, the solar/air double-source heat pump unit operates like a normal air-source heat pump system; When hot water is used, the hot water can promote the operation of the air source heat pump system, and achieve the effect of improving the heat exchange efficiency by increasing the conversion temperature.

The air source heat pump heat exchanger 12 is used for the first conversion of heat; followed by the heating of the water in the hot water storage tank 18 by the coil heater 29, the heat can finally be converted into the water in the hot water storage tank 18 .

The fan coil convection heat exchange terminal device 28 and the phase change material heat storage floor heating terminal device 27 are the user ends in the system, and the fan coil convection heat exchange terminal device 28 is used to directly supply heat to the user during the day; the phase change material The thermal storage floor heating terminal device 27 is used for absorbing heat during the day and supplying heat to the user through radiation and convection heat exchange at night, while maintaining the room temperature and reducing the heating demand for the next day; as shown in 1, the fan coil convection heat exchange The terminal device 28 and the phase change material thermal storage floor heating terminal device 27 are in a parallel relationship, and the circulating medium (which can be water, air or other fluid circulating medium) in the corresponding pipelines is heated in the hot water storage tank 18 After being heated in the heater, it is divided into two paths which flow into the fan coil convection heat exchange terminal device 28 and the phase change material heat storage floor heating terminal device 27 respectively. In the heater, a first pressure sensor 30, a first circulating water pump 31, a second pressure sensor 32, a check valve 33, and a second pressure sensor 32, a check valve 33 and a second Electric valve 35.

A second check valve 20, a first electric valve 21 and a second electric three-way valve 22 are arranged in sequence on the pipeline from the hot water storage tank 18 back to the solar collector 1, while the dual-source evaporator 5 is connected to the second electric valve 22. A first valve 6 is provided on the return water pipeline between the three-way valves 22 .

In addition, the hot water storage tank 18 is also connected with a water supply pipeline. The pipeline is provided with a fourth temperature sensor 23 , a fourth valve 24 , a third check valve 25 , and a first pressure sensor 26 in order along the direction away from each other.

Therefore, in this system, the dual-source evaporator 5 is connected with the solar collector 1, the air source heat pump heat exchanger 12, the hot water storage tank 18, the phase change material heat storage floor heating terminal device 27 and the fan coil convection heat exchange terminal respectively. The device 28 is connected in parallel or in series through valves, circulating water pumps and connecting pipelines to form a circuit that can supply heat and store heat at the same time.

The above system sets up multiple sets of temperature sensors and controllers that control the opening and closing of valves (for example, controller 1 and controller 2 in the figure), the controllers are connected to electric actuators, and the electric actuators are respectively connected to multiple sets of valves.

The solar thermal collector in the present example adopts a tracking type self-regulating solar thermal collector, and FIG. 2 and FIG. 3 show a specific implementation of the tracking type self-regulating solar thermal collector. The tracking self-adjusting solar collector in the figure mainly includes a solar collector plate 48 and a ray tracing mechanism;

The ray tracing mechanism further includes a ray tracing device 46 and a driving mechanism, wherein the driving mechanism includes a rocker arm 60, a fixed arm 61, a horizontal shaft 47, a balance rod 49, a horizontal motor 50, a horizontal transmission gear set 52, a pitch motor 51, a pitch motor The rotating shaft 62 , the pitch transmission gear set 53 and the semicircular adjustment gear 54 .

As shown in FIG. 2 , the horizontal rotating shaft 47 is located below the solar collector plate 48 , the solar collector plate 48 extends downward from the connecting portion, the horizontal rotating shaft 47 passes through the connecting portion, and the horizontal rotating shaft 47 , the connecting portion and the lower rocker The arms 60 form a pivotal connection. The balance rod 49 is used to stabilize the solar collector panel and transmit power to adjust the horizontal angle of the solar collector panel 48. At the end, two ends of the horizontal rod are hinged with a vertical rod; the ends of the two vertical rods away from the horizontal rod are hinged with the connecting rod fixed on the solar heat collecting panel 48 above. The rocker arm 60 is a hollow structure. The horizontal motor 50 and the horizontal transmission gear set 52 are located in the rocker arm 60. The horizontal transmission gear set 52 includes a first horizontal transmission gear, a second horizontal transmission gear, a third horizontal transmission gear and a horizontal gear shaft. , the first horizontal transmission gear, the second horizontal transmission gear, and the third horizontal transmission gear are all vertically arranged, wherein the two ends of the horizontal gear shaft are respectively fixed in the gear holes of the first horizontal transmission gear and the second horizontal transmission gear, and the third horizontal transmission gear The third horizontal transmission gear meshes with the second horizontal transmission gear, and the third horizontal transmission gear is fixedly connected to the side wall of the midpoint of the horizontal rod through a mandrel, the first horizontal transmission gear is a helical gear, and the output shaft of the horizontal motor 50 A drive gear is also coaxially fixed on the upper surface, and the drive gear is also a helical gear and meshes with the first horizontal transmission gear, so the torque output by the horizontal motor 50 passes through the first horizontal transmission gear, the horizontal gear shaft, the second horizontal transmission gear, The third horizontal transmission gear is specially delivered to the horizontal rod of the balance rod 49, and the horizontal rod rotates around the axial direction of the mandrel along with the third transmission gear, thereby driving the solar collector to adjust the level. A space for the two ends of the horizontal rod to swing up and down. In this embodiment, the space is a slit opened on the rocker arm 60 .

As shown in FIG. 2 , the fixed arm 61 is pivotally connected to the semicircular adjusting gear 54 through the pitching shaft 62, and the rocker arm 60 is fixedly connected to the semicircular adjusting gear 54. The pivoting direction of the pivotal connection is the pitching direction. It is orthogonal to the pivoting direction formed by the horizontal rotating shaft 47 , the connecting portion and the rocker arm 60 , that is, the horizontal direction. The fixed arm 61 is also a hollow structure, and the pitch motor 51 and the pitch transmission gear set 53 are arranged in it. The pitch motor 51 transmits the power to the semicircular adjustment gear 54 through the pitch transmission gear set to adjust the pitch of the rocker arm 60, and then completes the Pitch adjustment of solar collector panels.

The ray tracing device 46 is basically shown in FIG. 4 and includes nine ray tracing modules. The structure of the ray tracing module is a cube box with a length, width and height of 20mm. On the upper side is a filter plate 55 for reducing the brightness of the light, and on the lower side a photoresistor 56 is placed for ray tracing, so that the photoresistor can have obvious resistance difference during operation. The ray tracing modules are evenly arranged on the plane in a cross shape along the outer contours of the two semicircular bases. In this embodiment, the photoresistor 56 in the central part (the central 0 o'clock position) is located on the normal line of the solar collector plate. At the same time, it is also the vertical intersection of the two semicircular bases, and one of the two semicircular bases is arranged along the rotation circumference of the horizontal axis 47, so the photoresistor 56 on the semicircular base The other is arranged along the direction of the horizontal adjustment of the solar collector plate, and the other is arranged along the rotation circumference of the semicircular adjustment gear 54, so the photoresistor 56 on the semicircular base is arranged along the direction of the pitch adjustment of the solar collector plate. .

When sunlight irradiates the ray tracing device, the nine photoresistors 56 are irradiated by light of different intensities, and the resistance values change. For pitch adjustment, adjust the normal line of the solar collector 48 to rotate in the direction with the smallest resistance value. After the adjustment is completed, judge the nine photoresistors again. If the photoresistor in the central part is not the lowest value of resistance, re-adjust the normal of the solar collector to align with the new position with the lowest resistance.

FIG. 5 is a structural diagram of the phase change material heat storage floor heating terminal device used in this embodiment—the convection-radiation combined phase change heat storage floor, which includes a ground layer 40 and a load-bearing structure layer 39 from top to bottom. , the air layer 41, the moisture-proof layer 42, the phase change material layer 43 and the thermal insulation layer 44; the load-bearing structure layer 39 includes a plurality of continuous load-bearing structures, the load-bearing structure is divided into a horizontal part and a vertical part, and the upper surface of the horizontal part is tightly It is attached under the ground layer, and there are aligned heat exchange holes 35 corresponding to the ground layer and the horizontal part, and the diameter is 50nm; Pass through the remaining layers below until it is supported on the building structure layer. The ground coils 45 are laid in the layer of the change material, and a deformation seam 38 is arranged between the phase change materials wrapping the two adjacent ground coils, so as to leave space for the volume change of the phase change material. The ground coil 45 is connected to the hot water storage tank of the external solar energy or air source heat pump heating system, and can provide heat to the phase change material layer 43 when the sunshine is sufficient, and the phase change material layer 43 phase change heat storage; close the valve at night, The phase change material layer releases heat during phase change, and the air layer and heat exchange holes enhance heat exchange, effectively increasing the temperature in the room. The load-bearing structure is a load-bearing structure made of high thermal conductivity, high strength and lightweight titanium alloy. The ground layer 40 is a cement ground layer. The phase change material is a microcapsule phase change material of n-octadecane (core material) + titanium dioxide-polyurea (wall material), the phase change temperature is 29.66°C, and the latent heat of phase change is 181.1J/g; and the two adjacent sites are Deformation slits are provided in the phase change material between the tubes. The phase transition temperature of the microcapsule phase change material used is 29.66°C, and the temperature of the hot water supplied by the solar energy or the air source heat pump is higher than the phase transition temperature, which can make the phase transition heat storage. A heat exchange hole with a diameter of 50nm is opened on the ground layer. When the phase change material releases heat, the heat exchange hole at the lower temperature is the air intake hole, and the heat exchange hole at the higher temperature is the heat dissipation hole, which circulates in the air layer. , and increase convection dissipation on the basis of radiation heat dissipation in the ground layer. The load-bearing structure made of high thermal conductivity, high strength and lightweight titanium alloy not only has strong load-bearing capacity, but also has good thermal conductivity. The moisture-proof layer is used to avoid moisture returning due to the passage of water vapor. Heat is released in the direction of the structural layer; finally, if the convection-radiation combined phase change heat storage floor in this embodiment is located at the corner, the corner insulation material 36 as shown in the figure can be used to reduce the self-phase change material to the wall. direction to release heat.

The system in this embodiment can realize the solar energy and low-temperature air source heat pump-assisted phase-change heat storage heat supply method of the present invention. The solar/air dual-source heat pump unit is used as the core component for coupled heat supply, and the heat from solar energy can be collected. The hot water or circulating medium that does not meet the heating requirements of the device 1 is transferred to the air source heat pump system, and the effect of improving the heat exchange efficiency is achieved by increasing the conversion temperature.

The system has two operating conditions, namely heat storage and heat supply; the system has three operating modes, which are only the solar heat collection system heat supply and heat storage mode, and only the air source heat pump system. Thermal storage mode and coupled solar energy and air source heat pump mode.

When the solar radiation intensity is high, the solar collector system is sufficient to meet the heating requirements of the room, so the system works in the heat storage mode of only the solar collector system; when the solar radiation intensity is low, the solar collector system is not enough to meet the room's heating requirements. When heating is required, the air source heat pump also needs to work at the same time, so the system works in the coupled mode of solar energy and air source heat pump; if it encounters cloudy days without sunshine, the air source heat pump needs to work alone, and the system works in only the air source heat pump system. Thermal storage mode. In the solar-air source heat pump coupling mode, the dual-source evaporator 5 can circulate three media for heat exchange, so that the refrigerant can exchange heat with the solar hot water in the inner tube and the outer surface air at the same time, and the heat pump can exchange heat with the air at the same time or separately. Heat exchange with liquid heat source can realize T-level utilization of energy.

In addition, the following strategies are adopted in the operation of the system in this embodiment:

Strategy 1: Energy storage and peak shifting, terminal coordination.

In the case of the dual energy complementation of solar energy and air source heat pump, the unfavorable time period, suitable time period and favorable time period for the operation of the main engine of the system are divided according to the needs of users.

The unfavorable period is the period with the lowest dry bulb temperature of the day, and it is also the period with the worst heating performance of the air source heat pump;

The favorable period is the period with the highest dry bulb temperature in a day, and it is also the period with the best heating performance of the air source heat pump;

other time periods are suitable time periods;

In favorable periods, since the external energy that can be directly collected is relatively sufficient, even exceeding the heating demand of indoor users, the system should be actively turned on and work under heat storage conditions to store heat in advance, and can start heating according to user settings.

In a suitable time period, the directly collected external energy may only just meet the heating needs of indoor users, or even be slightly insufficient, so the passive opening strategy is adopted in this time period, and heating is not actively performed, and heating is started according to user settings; During heating (for example, during certain hours of the day, there is no one in the room, and direct heating does not need to be turned on), energy storage can be performed appropriately, and phase change materials can be preferentially used for energy storage.

During unfavorable periods, it is difficult for the system to collect energy from the outside world (the period with the lowest bulb temperature is often the period when the solar radiation intensity is low, such as at night), and indoor users give priority to heating and utilize the energy stored in the system during favorable periods for heating.

Strategy 2: Matching the volume of the hot water storage tank

The lower limit of the temperature of the thermal storage tank 18 is set to 30°C according to the phase transition temperature (29.66°C) of the phase change material used for the thermal storage floor.

Considering the heat dissipation loss, the power consumption is converted according to the daily average COP of the host at -9°C, and the upper limit of the temperature of the hot water storage tank is set to 45°C, which has better climate suitability and more energy saving.

Strategy three:

Through the operation of the main engine in the high energy efficiency period, the system uses the hot water storage tank and the phase change thermal storage floor to store energy to meet the heating demand in the low energy efficiency period, so as to adjust the contradiction between supply and demand and optimize the system matching to achieve the goal of reliable operation, high efficiency and energy saving. .

This embodiment combines the above three strategies, aiming at the flow rate and temperature of the circulating medium in each pipeline of the heat source, the hourly changes of outdoor meteorological parameters and the changes of indoor environmental parameters, hourly and cumulative system energy consumption, and hourly water tank internal temperature The distribution and changes are monitored hourly, and the switching of the heat source mode is automatically controlled.

Therefore, the specific work flow of the system is shown in Figure 6. First, the operation period is judged, and the current operation strategy is determined according to the result of the interruption, and then the temperature sensor set in the hot water storage tank 18 is used to sense the water temperature and start the working mode judgment. When the hot water temperature in the hot water tank is less than 40°C, according to the relevant hot water temperature collected by the controllers 1 and 2, it is determined whether the first circulating water pump 9 and the second circulating water pump 16 are turned on (the air source heat pump unit is chained on or off) , specifically:

① When the water temperature of the solar collector is greater than or equal to 30°C, only the first circulating water pump 9 is turned on, and the system works in the heat supply and heat storage mode of the solar collector only;

② When the water temperature of the solar collector is greater than or equal to 27°C and less than 30°C, the solar collector and the air source heat pump unit operate jointly. At this time, the first circulating water pump 9 on the solar collector side and the air source heat pump unit side The second circulating water pump 16 is in the open state, and the system works in the coupled mode of solar energy and air source heat pump.

③ When the water temperature of the solar collector is less than 27°C, the first circulating water pump 9 on the solar collector side stops running, the second circulating water pump 16 on the air source heat pump unit side is on, and the system works in the air source heat pump system only. In heat supply and heat storage mode.

As shown in the figure, when the temperature of the hot water in the hot water storage tank is not less than 40°C, the system starts the heating mode according to the customized heating temperature at the end of the user.

In addition, in order to ensure that the phase change material heat storage floor heating terminal device can store heat in advance during the day, when the outlet water temperature of the phase change material heat storage floor is lower than the phase change temperature (close to 30°C), the system starts the third circulation valve to carry out phase change. Change material heat storage. Similarly, as shown in Figure 6, the system will also determine the working mode according to the water temperature of the solar collector. When the water temperature of the solar collector is higher than the phase change temperature, it can be The heating system works in the heat supply and heat storage mode. Since the phase transition temperature is determined to be close to 30°C in this embodiment, the judgment criteria for determining the working mode here are substantially the same as those described above. Therefore, in FIG. The condition for the stepless control of compressor 1 to open the compressor is unified as "the collector temperature is less than the phase transition temperature".

As shown in FIG. 6 , the working process of the ray tracing solar collector in this embodiment is as follows. When sunlight irradiates the ray tracer device, the nine photoresistors 56 are irradiated by light of different intensities, and the resistance value changes. Change, according to the photoresistor corresponding to the minimum resistance value, the position of the strongest sunlight can be judged, and the normal line of the solar collector panel can be adjusted by horizontal adjustment and pitch adjustment, and the normal line of the solar collector panel is rotated to the direction with the smallest resistance value.

In this embodiment, as shown in 6, first, it is judged whether the resistance value of the photoresistor at 0 o'clock in the center of the ray tracing solar collector is the smallest. Among the photoresistors arranged in the horizontal direction, the photoresistor with the smallest resistance value is rotated by a fixed value, which is 15° in this embodiment. After the adjustment is completed, the resistance values of the photoresistors arranged in the horizontal direction are compared again to determine Among the photoresistors arranged in the horizontal direction, whether the resistance value of the photoresistor at the 0 o'clock position is the smallest, if not, turn it again. Until the lowest resistance of each photoresistor arranged in the horizontal direction is the photoresistor at the central 0 o'clock position or stop after cyclic adjustment ten times. Next is the adjustment in the vertical direction, and the process is the same as that in the horizontal direction. It is also possible to adjust vertically first and then horizontally.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (10)

1. A solar energy and low temperature air source heat pump assisted phase change heat storage heating system, comprising: Solar collectors, solar/air dual-source heat pump units, hot water storage tanks and user terminals connected by pipelines; The solar collector is used for absorbing solar energy to heat the circulating medium; The solar/air dual source heat pump unit is used to exchange the heat in the low temperature air to the circulating medium in the hot water storage tank with the assistance of the connected heated circulating medium, or only exchange the heat in the low temperature air into the circulating medium in the hot water storage tank; The user terminal is used for heating the user by using the heat of the circulating medium in the hot water storage tank; It also includes a cycle selection mechanism for selecting the cycle of the circulating medium and opening and closing the solar/air dual-source heat pump unit according to the following strategies: When the temperature of the circulating medium is higher than the first temperature threshold, the circulating medium only circulates between the solar collector and the hot water storage tank through the pipeline, and the solar/air dual-source heat pump unit does not work; When the temperature of the circulating medium is lower than the first temperature threshold but higher than the second temperature threshold, the circulating medium passes through the pipeline in parallel between the solar collector and the hot water storage tank, the solar thermal collector and the hot water storage tank solar/air Circulation between dual-source heat pump units, solar/air dual-source heat pump units work; When the temperature of the circulating medium is lower than the second temperature threshold, the circulating medium stops circulating, and only the solar/air dual-source heat pump unit works. 2 . The system according to claim 1 , wherein the cycle selection mechanism comprises a first temperature sensor and a first electric three-way valve arranged in the order of the water flow on the pipeline of the water outlet of the solar collector; The first electric three-way valve divides the pipeline into two paths, one of which is connected to the hot water storage tank, and the other is connected to the solar/air dual-source heat pump unit; It also includes a first circulating water pump 9 arranged on the pipeline between the first electric three-way valve and the hot water storage tank, and a second electric water pump 9 arranged on the pipeline returning from the solar/air dual-source heat pump unit to the solar collector. Three-way valve; the second electric three-way valve is also on the pipeline from the self-storage hot water tank back to the solar collector; and a controller for opening and closing and switching the circulation path of the circulating medium and opening and closing the circulating medium by opening and closing the corresponding circulating water pump and gating the corresponding electric three-way valve according to the temperature sensed by the first temperature sensor and according to the aforementioned strategy. Closed solar/air dual source heat pump unit. 3. The system of claim 1, wherein the first temperature threshold is 28-31°C, and the second temperature threshold is 25-28°C. 4 . The system according to claim 1 , wherein the user end comprises a phase change material thermal storage floor heating terminal device, which is used for utilizing the thermal storage properties of the phase change material to control the circulation from the hot water storage tank. 5 . The heat of the medium is stored, and heat is supplied to the user through radiation and convection heat exchange. 5 . The system according to claim 4 , wherein the phase change temperature of the phase change material in the terminal device for thermal storage floor heating of the phase change material is 27.99° C.-30.99° C. 6 . 6 . The system according to claim 5 , wherein the phase change material thermal storage floor heating terminal device is in the shape of a floor, and comprises a ground layer, a load-bearing structure layer, an air layer, a moisture-proof layer, a phase Variable material layer and thermal insulation layer; The ground layer and the load-bearing structure layer are provided with heat exchange holes; A ground coil pipe is laid in the change material layer, and a deformation joint is set in the phase change material between the adjacent two ground coil pipes; The ground pipe is connected to the hot water storage tank. The system according to claim 5, wherein the phase change material of the phase change material layer is a microcapsule phase change material with n-octadecane as the core material and titanium dioxide-polyurea as the wall material , the phase transition temperature is 29.66℃, and the latent heat of phase transition is 181.1J/g. 8. The system according to claim 1, wherein the evaporator in the solar/air dual-source heat pump unit is a dual-source evaporator, comprising an outer casing and an inner pipe located in the outer casing; The inner tube can pass the circulating medium, the outer shell can be in contact with the low-temperature air, and the refrigerant can pass between the outer shell and the inner tube; and the refrigerant can exchange heat with the circulating medium and the low-temperature air through the outer shell and the inner tube. 9. A solar energy and low-temperature air source heat pump-assisted phase-change heat storage heat supply method, characterized in that, comprising: Absorb solar energy with solar collectors to heat the circulating medium; Using a solar/air dual-source heat pump unit, the heat in the low-temperature air is exchanged to the circulating medium in the hot water storage tank with the assistance of the connected heated circulating medium, or only the heat in the low-temperature air is exchanged to the storage tank. In the circulating medium in the hot water tank; When the temperature of the circulating medium output by the solar collector is higher than the first temperature threshold, the circulating medium only circulates between the solar collector and the hot water storage tank through the pipeline, and the solar/air dual-source heat pump unit does not work; When the temperature of the circulating medium output by the solar collector is lower than the first temperature threshold but higher than the second temperature threshold, the circulating medium passes through the pipeline in parallel between the solar collector and the water storage tank, the solar collector and the storage tank. The hot water tank solar/air dual-source heat pump unit circulates, and the solar/air dual-source heat pump unit works; When the temperature of the circulating medium output by the solar collector is lower than the second temperature threshold, the circulating medium stops circulating, and only the solar/air dual-source heat pump unit works; Through the user end, the heat of the circulating medium in the hot water storage tank is used to heat the user, and the heat from the circulating medium in the hot water storage tank is heated by the heat storage property of the phase change material deployed on the floor side of the user end. It is stored, and heat is supplied to users through radiation and convection heat exchange. 10. The method according to claim 9, further comprising: dividing the whole day into unfavorable time periods, suitable time periods and favorable time periods; The unfavorable period is the period of the day when the dry bulb temperature is the lowest; The favorable period is the period of the day when the dry bulb temperature is the highest; other time periods are suitable time periods; Use solar collectors and/or solar/air dual-source heat pump units to collect heat during favorable periods, and use hot water storage tanks and phase-change heat storage floors to store heat; During unfavorable times, the heat storage of the hot water storage tank and the phase change heat storage floor is used to provide heat for the user.

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