A heat collecting plate with liquid storage area

Abstract

The invention relates to the field of solar panel manufacturing. The working fluid in the existing heat collecting plate is in a bottom-in and top-out working mode, which has the defects of uneven heat absorption, low energy efficiency ratio and poor oil return. The invention provides a heat collecting plate with a liquid storage area, including a panel body and a working fluid flow channel, the working fluid flow channel extends in the vertical direction and forms an evaporation area, the panel body is provided with a working fluid inlet and a working fluid outlet respectively connected to the working fluid flow channel, the working fluid inlet is located at the top of the evaporation area, and the working fluid outlet is located at the bottom of the evaporation area; a liquid storage area is provided between the working fluid inlet and the evaporation area; the liquid storage area is located above the evaporation area, the liquid storage area includes a liquid storage pipe, the working fluid inlet is located on one side of the liquid storage pipe, the bottom of the liquid storage pipe is connected to the working fluid flow channel, the top of the liquid storage pipe is connected to a balancing pipe for guiding gaseous working fluid and balancing the air pressure in the pipe, and the other end of the balancing pipe is communicated with the working fluid flow channel at the bottom of the evaporation area; the heat absorption effect is balanced, the energy efficiency ratio is high, and the oil return is smooth.

Description

Technical Field

[0001] The invention relates to the field of solar heat collecting plate manufacturing, in particular to a heat collecting plate with a liquid storage area. Background Art

[0002] The heat collecting plate is an important component of solar heterogeneous heating equipment. Its interior is full of oil flow channels. When the working medium flows through the flow channels, the (liquid-gas) phase changes occur, thereby absorbing heat from the environment to achieve the purpose of improving energy efficiency. In the existing heat collecting plate layout structure, the flow channel usually adopts the method of oil (liquid is the working medium, referred to as the working medium; oil is lubricating oil, used to lubricate the compressor) entering from the bottom and exiting from the top. After long-term use, it is found that the current heat collecting plate has the following defects:

[0003] 1. The bottom-in and top-out supply and return method creates a dead corner at the bottom or edge of the heat collecting plate. The oil-liquid mixed medium cannot enter this area during operation, which wastes the evaporation area of ​​the heat collecting plate, affects the heat absorption of the plate surface and thus affects the energy efficiency of the system; the evaporated gaseous medium will accumulate in the dead corner, destroying the overall pressure balance of the heat collecting plate, and in severe cases, causing local cracking of the heat collecting plate.

[0004] 2. The oil and the working fluid are in a miscible state. As the working fluid temperature drops, the solubility of the oil will be greatly reduced. The working fluid will be separated into oil and liquid in the heat collecting plate. The separated oil cannot evaporate and naturally sinks under the influence of gravity. The bottom-in and top-out heat collecting plate cannot take away the accumulated oil at the bottom. Long-term accumulation and poor oil return will lead to oil shortage in the system, which will in turn affect the life of the compressor. Without oil sealing of mechanical equipment, the system efficiency will be greatly reduced.

[0005] Especially in extremely cold working conditions, the poor oil return is aggravated. For example, at -10 degrees Celsius to -30 degrees Celsius, the ambient temperature is closer to the boiling point of the working fluid. The smaller the difference between the ambient temperature and the boiling point of the working fluid, the milder the phase change of the working fluid in the flow channel. When the working fluid is converted from liquid to gas, its volume will expand. The expanded gaseous working fluid can also carry some lubricating oil when it returns from the flow channel through the upper outlet. The mild phase change will cause the activity of the gaseous working fluid to weaken, and its ability to return oil will be further weakened, or even completely lost. After working in extremely cold conditions for a long time, the lubricating oil will continue to accumulate in the flow channel (at the bottom or edge of the heat collecting plate). Eventually, the compressor will malfunction due to lack of lubricating oil and will not work.

[0006] 3. In addition, when the ambient temperature of extremely cold working conditions is close to the boiling point of the working fluid, on the one hand, the liquid working fluid cannot obtain enough heat and cannot be completely evaporated into a gaseous working fluid. As the operating time goes by, the liquid working fluid will accumulate at the bottom of the heat collecting plate, and even the entire plate surface will become a "liquid storage tank", causing the working system where the heat collecting plate is located to appear to be "lack of working fluid", causing the compressor in the system to have high temperature, and in severe cases, the compressor will be burned.

[0007] 4. On the other hand, the liquid working medium enters from the bottom of the heat collecting plate. Since it cannot get enough heat to evaporate into gas, the liquid working medium is greatly affected by gravity, which will hinder the return air of the compressor, greatly increase the resistance of the system in the heat collecting plate part, increase the power consumption of the compressor and reduce the energy efficiency ratio. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the defects existing in the above-mentioned prior art and provide a heat collecting plate with a liquid storage area, which has uniform evaporation, can fully absorb heat, has smooth oil return and high energy efficiency ratio.

[0009] To achieve the above-mentioned purpose, the present invention is realized through the following technical solutions: a heat collecting plate with a liquid storage area, comprising a panel body, a working fluid flow channel is arranged in the panel body, the working fluid flow channel extends in the vertical direction and forms an evaporation area, the panel body is also provided with a working fluid inlet and a working fluid outlet respectively connected to the working fluid flow channel, the working fluid inlet is located at the top of the evaporation area, and the working fluid outlet is located at the bottom of the evaporation area; a liquid storage area for storing liquid working fluid and balancing the flow rate of liquid working fluid is also provided between the working fluid inlet and the evaporation area; the liquid storage area is located above the evaporation area, the liquid storage area comprises a liquid storage pipe, the working fluid inlet is located on one side of the liquid storage pipe, the bottom of the liquid storage pipe is connected to the working fluid flow channel, the top of the liquid storage pipe is connected to a balancing pipe for guiding gaseous working fluid and balancing the air pressure in the pipe, and the other end of the balancing pipe is communicated with the working fluid flow channel at the bottom of the evaporation area.

[0010] In the above technical solution, the flow channel is set from top to bottom. When the liquid working medium flows in the flow channel under the push of gravity, it does not need to overcome gravity to do work; on the contrary, its gravitational potential energy is converted into kinetic energy, which can reduce the system resistance and reduce the power consumption of the compressor, thereby improving energy efficiency. After the oil and liquid are separated, the (lubricating) oil is naturally deposited to the lowest point of the heat collecting plate under the influence of gravity, and can smoothly return to the compressor of the system where the heat collecting plate is located through the working medium outlet, ensuring the life and efficiency of the compressor and improving the working stability; at the same time, the balance pipe can balance the air pressure in the upper space of the liquid storage area to ensure the liquid level balance of the liquid working medium in the liquid storage area.

[0011] A further preferred embodiment of the present invention is as follows: the liquid storage pipeline is a grid-like structure, and a barrier portion is provided in the liquid storage pipeline; the barrier portion is close to the working fluid inlet and arranged in the horizontal direction, so that the liquid storage pipeline near the working fluid outlet is sparsely arranged; the liquid working fluid enters the liquid storage area from the working fluid inlet and can quickly spread to a distant place through the barrier portion, and at the same time, a small amount of gaseous working fluid generated in the liquid storage area can rise to the top in time, reducing the impact on the flow rate of the liquid working fluid.

[0012] A further preferred solution of the present invention is: the working fluid flow channel includes a plurality of main flow channels extending in the vertical direction and secondary flow channels for connecting the main flow channels; a group of secondary flow channels is provided on one side or both sides of the main flow channel and the secondary flow channels in the same group are arranged alternately; the secondary flow channels on both sides of the same main flow channel, one group of secondary flow channels and the other group of secondary flow channels are arranged alternately. By providing the main flow channel and the secondary flow channel, the area of ​​the working fluid flow channel is increased, and then the contact area with the liquid working fluid is increased, which can increase the heat absorption effect.

[0013] A further preferred solution of the present invention is: a flow-limiting and flow-dividing connecting pipe is provided between the liquid storage pipe and the working medium flow channel; the cross-sectional area of ​​the inlet end of the flow-limiting and flow-dividing connecting pipe is smaller than the cross-sectional area of ​​the outlet end thereof, the inlet end of the flow-limiting and flow-dividing connecting pipe is connected to the bottom of the liquid storage pipe, and the outlet end of the flow-limiting and flow-dividing connecting pipe is connected to the working medium flow channel at the top of the evaporation zone. The flow-limiting and flow-dividing connecting pipe allows the liquid working medium to be more evenly separated when entering the evaporation zone, and absorbs heat more fully.

[0014] A further preferred solution of the present invention is that the flow limiting and diverting connecting pipeline includes at least one inlet end and at least two outlet ends, the diameter of the inlet end is the same as the diameter of the outlet end and the number of the inlet ends is less than the number of the outlet ends.

[0015] A further preferred solution of the present invention is that the flow-limiting and flow-diverting connecting pipe has a multi-stage flow-diverting structure.

[0016] A further preferred solution of the present invention is: an oil return pipe is also provided on the panel body, the oil return pipe is located at the bottom of the evaporation zone, the upper port of the oil return pipe is connected to the working fluid flow channel at the bottom of the evaporation zone, and the lower port of the oil return pipe is connected to the working fluid outlet.

[0017] A further preferred solution of the present invention is that the oil return pipe is arranged in an S shape.

[0018] A further preferred solution of the present invention is: a flow limiting collection area is further provided at the bottom of the evaporation area, and the pipes in the flow limiting collection area are staggered in a sparse and dense manner in the vertical direction; and the upper port of the oil return pipe is provided at the bottom of the flow limiting collection area.

[0019] A further preferred embodiment of the present invention is as follows: the heat collecting plate is of a symmetrical structure, comprising two groups of liquid storage areas and evaporation areas arranged in parallel, a tee pipe and / or a tee joint is provided between the two groups of liquid storage areas and evaporation areas; the working fluid inlets on the two liquid storage areas are arranged opposite to each other and connected by a tee pipe / tee joint, and the working fluid outlets at the bottom of the two evaporation areas are arranged opposite to each other and connected by another tee pipe or tee joint.

[0020] In summary, the present invention has the following beneficial effects: 1. The working fluid adopts a top-in-bottom-out working mode, which reduces the system operation resistance and the power consumption of the compressor in the power consumption system, and the area of ​​the evaporation zone is fully utilized through the liquid storage area and the current limiting and shunt connecting pipe, avoiding the formation of evaporation blind spots and improving the energy efficiency ratio; 2. The oil return capacity is strong, which can avoid the long-term deposition of (lubricating) oil in the heat collecting plate and extend the service life of the compressor in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of a heat collecting plate with a liquid storage area.

[0022] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0023] In the figure: 1, working fluid inlet; 2, liquid storage area; 21, barrier part; 3, flow limiting and diversion connecting pipeline; 4, evaporation area; 41, main flow channel; 42, secondary flow channel; 5, balance pipeline; 6, flow limiting and collecting area; 7, oil return pipe; 8, working fluid outlet. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0025] This embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0026] like Figure 1 and Figure 2 As shown, a heat collecting plate with a liquid storage area is shown, including a panel body, in which a working fluid flow channel is arranged, and the working fluid flow channel includes a plurality of main channels 41 extending in the vertical direction and secondary channels 42 for connecting the main channels 41. A group of secondary channels 42 is arranged on one side or both sides of the main channel 41, and the secondary channels 42 in the same group are arranged alternately. Among the secondary channels 42 located on both sides of the same main channel 41, one group of secondary channels 42 is staggered with the other group of secondary channels 42. The multiple main channels 41 of the working fluid flow channel extend side by side in the vertical direction and form an evaporation zone 4. When in use, the panel body is vertically arranged on the outer surface of the wall or is tilted in the open air through a fixed frame (in addition, according to the actual needs, the panel can also be arc-shaped).

[0027] The panel body is also provided with a working medium inlet 1 and a working medium outlet 8 respectively connected to the working medium flow channel. The working medium inlet 1 is located at the top of the evaporation area 4, and the working medium outlet 8 is located at the bottom of the evaporation area 4. A liquid storage area 2 for storing liquid working medium and balancing the flow of liquid working medium (entering the evaporation area 4) is also provided between the working medium inlet 1 and the evaporation area 4. The liquid storage area 2 is located above the evaporation area 4. The liquid storage area 2 includes a liquid storage pipeline. The working medium inlet 1 is located on one side of the liquid storage pipeline. The bottom of the liquid storage pipeline is connected to the working medium flow channel. The top of the liquid storage pipeline is connected to a balancing pipeline 5 for dredging gaseous working medium and balancing the air pressure in the pipe. The other end of the balancing pipeline 5 is connected to the working medium flow channel at the bottom of the evaporation area 4. Part of the liquid working medium in the liquid storage area 2 is converted into gas after absorbing heat, and is extracted from the panel body through the balancing pipeline 5 at the top, so as to ensure the air pressure balance above the liquid surface of the liquid working medium in the liquid storage area 2.

[0028] The liquid storage pipeline is a grid structure, consisting of two groups of pipelines that are crisscrossed and interconnected, one group of pipelines is arranged horizontally, and the other group of pipelines is arranged vertically. A barrier 21 is provided in the liquid storage pipeline. (The barrier 21 is the flow channel closing point on the heat collecting plate. No flow channel is set in this area to block the passage of the working fluid.) The barrier 21 is close to the working fluid outlet 8 and arranged in the horizontal direction, so that the liquid storage pipeline near the working fluid outlet 8 is sparsely arranged.

[0029] A flow-limiting and flow-dividing connecting pipe 3 is provided between the liquid storage pipe and the working medium flow channel. The cross-sectional area of ​​the inlet end of the flow-limiting and flow-dividing connecting pipe 3 is smaller than the cross-sectional area of ​​the outlet end thereof, the inlet end of the flow-limiting and flow-dividing connecting pipe 3 is connected to the bottom of the liquid storage pipe, and the outlet end of the flow-limiting and flow-dividing connecting pipe 3 is connected to the working medium flow channel at the top of the evaporation area 4.

[0030] The flow-limiting and shunting connecting pipe 3 includes at least one inlet end and at least two outlet ends, the diameter of the inlet end is the same as the diameter of the outlet end and the number of the inlet ends is less than the number of the outlet ends. The flow-limiting and shunting connecting pipe has a multi-stage shunting structure, and the number of pipes increases with each stage. In this embodiment, a three-stage shunting structure is taken as an example. After the liquid working medium in the liquid storage area 2 passes through the flow-limiting and shunting connecting pipe 3, it is evenly transported to each main channel 41. In the process of the liquid working medium in the main channel 41 flowing down along the pipe wall under the action of gravity, a part of the liquid working medium absorbs heat and is directly converted into a gaseous working medium and enters the working system where the heat collecting plate is located from the working medium outlet 8 below, and the other part of the liquid working medium enters the secondary flow channel 42 when flowing down along the pipe wall of the main channel 41, and is converted into a gaseous working medium after absorbing heat, and finally returns to the compressor of the working system where the heat collecting plate is located from the working medium outlet 8 below.

[0031] In this embodiment, the panel body is further provided with a flow limiting collection area 6 and an oil return pipe 7. The flow limiting collection area 6 is located at the bottom of the evaporation area 4, and the pipes of the flow limiting collection area 6 are staggered in a sparse and dense manner in the vertical direction. The oil return pipe 7 is located at the bottom of the flow limiting collection area 6 and is arranged in an S shape.

[0032] The upper end of the oil return pipe 7 is arranged at the bottom of the flow limiting and collecting area 6 , and is connected to the working medium flow channel at the bottom of the evaporation area 4 after passing through the flow limiting and collecting area 6 . The lower end of the oil return pipe 7 is connected to the working medium outlet 8 .

[0033] In the evaporation area 4, after the liquid working medium evaporates into a gaseous working medium, the lubricating oil is separated and, under the influence of gravity, gathers in the flow limiting collection area 6 at the bottom and returns to the compressor of the working system through the return oil pipe 7 or directly from the working medium outlet 8.

[0034] It should be noted that the heat collecting plate in this embodiment is a symmetrical structure, including two groups of liquid storage areas 2 and evaporation areas 4 arranged in parallel, and a three-way pipe and a three-way joint are provided between the two groups of liquid storage areas 2 and evaporation areas 4. The working fluid inlets 1 on the two liquid storage areas 2 are arranged opposite to each other and connected by a three-way pipe, and the working fluid outlets 8 at the bottom of the two evaporation areas 4 are arranged opposite to each other and connected by another three-way joint. Such an arrangement can improve the space utilization rate of the heat collecting plate.

[0035] The specific working principle of the present invention is as follows: After the heat collecting plate is installed in the working system, the system is started (the compressor is working), and the oil-liquid mixture of the liquid working fluid and the lubricating oil enters the liquid storage area from the working fluid inlet on the upper part of the panel body, and the mixed liquid spreads along the barrier part. Since the flow rate of the mixed liquid flowing into the evaporation area from the liquid storage area is greater than the flow rate of the mixed liquid flowing into the evaporation area from the liquid storage area (the flow rate can be controlled by the cross-sectional area of ​​the working fluid inlet and the cross-sectional area of ​​the inlet of the flow-limiting and shunting connecting pipe), the liquid level of the mixed liquid in the liquid storage area rises, and part of the liquid working fluid in the liquid storage area is converted into gas after absorbing heat, and is discharged through the balance pipe at the top, so as to ensure the balance of air pressure above the liquid surface in the liquid storage area. As the liquid level of the mixed liquid in the liquid storage area rises, under the action of gravity, the hydraulic pressure at the inlet of the flow-limiting and shunting connecting pipe increases, the flow rate increases, and the flow rate also increases until it maintains a dynamic balance with the flow rate at the working fluid inlet. After the mixed liquid is diverted by the flow-limiting and diverting connecting pipe, it evenly enters the evaporation zone. The liquid working fluid in the mixed liquid absorbs heat and is converted into a gaseous working fluid during the natural sedimentation process under the action of gravity, while the lubricating oil naturally settles to the flow-limiting collection area at the bottom of the evaporation zone. After being collected, it is discharged from the working fluid outlet through the return oil pipe (a small amount of lubricating oil is directly discharged from the working fluid outlet).

[0036] After passing through the evaporation zone, the working fluid converted into gaseous state and the gaseous working fluid in the balance pipe are discharged from the lowest point of the flow limiting collection zone. The heat collecting plate with this structure has a smooth internal working fluid flow path, and the liquid working fluid does not need to overcome gravity to flow, which reduces the system operation resistance and the power consumption of the compressor, thereby improving the energy efficiency ratio. There is no possibility of oil accumulation at the bottom of the heat collecting plate, which can extend the service life of the compressor in the working system where the heat collecting plate is located.

Claims

1. A heat collecting plate with a liquid storage area, comprising a panel body, wherein a working fluid flow channel is provided in the panel body, wherein the working fluid flow channel extends in a vertical direction and forms an evaporation area (4), and wherein a working fluid inlet (1) and a working fluid outlet (8) are respectively connected to the working fluid flow channel on the panel body, wherein: The working medium inlet (1) is located at the top of the evaporation zone (4), and the working medium outlet (8) is located at the bottom of the evaporation zone (4); a liquid storage area (2) for storing liquid working medium and balancing the flow of liquid working medium is provided between the working medium inlet (1) and the evaporation zone (4); the liquid storage area (2) is located above the evaporation zone (4), the liquid storage area (2) comprises a liquid storage pipeline, the working medium inlet (1) is located at one side of the liquid storage pipeline, the bottom of the liquid storage pipeline is connected to the working medium flow channel, the top of the liquid storage pipeline is connected to a balancing pipeline (5) for channeling gaseous working medium and balancing the gas pressure in the pipeline, and the other end of the balancing pipeline (5) is communicated with the working medium flow channel at the bottom of the evaporation zone (4).

2. The heat collecting plate according to claim 1, characterized in that: The liquid storage pipeline is a grid-like structure, and a barrier portion (21) is provided in the liquid storage pipeline; the barrier portion (21) is close to the working medium inlet (1) and arranged in the horizontal direction, so that the liquid storage pipeline close to the working medium outlet (8) is sparsely arranged.

3. The heat collecting plate according to claim 1 or 2, characterized in that: The working fluid flow channel comprises a plurality of main flow channels (41) extending in a vertical direction and secondary flow channels (42) for connecting the main flow channels (41); a group of secondary flow channels (42) is provided on one side or both sides of the main flow channel (41), and the secondary flow channels (42) in the same group are arranged alternately; and the secondary flow channels (42) in one group and the secondary flow channels (42) in another group are arranged alternately on both sides of the same main flow channel (41).

4. The heat collecting plate according to claim 1 or 2, characterized in that: A flow-limiting and flow-dividing connecting pipe (3) is provided between the liquid storage pipe and the working medium flow channel; the cross-sectional area of ​​the inlet end of the flow-limiting and flow-dividing connecting pipe (3) is smaller than the cross-sectional area of ​​the outlet end thereof; the inlet end of the flow-limiting and flow-dividing connecting pipe (3) is connected to the bottom of the liquid storage pipe, and the outlet end of the flow-limiting and flow-dividing connecting pipe (3) is connected to the working medium flow channel at the top of the evaporation region (4).

5. The heat collecting plate according to claim 4, characterized in that: The flow limiting and diverting connecting pipeline (3) comprises at least one inlet end and at least two outlet ends, the diameter of the inlet end is the same as the diameter of the outlet end, and the number of the inlet ends is less than the number of the outlet ends.

6. The heat collecting plate according to claim 5, characterized in that: The flow-limiting and flow-dividing connecting pipe has a multi-stage flow-dividing structure.

7. The heat collecting plate according to claim 1 or 2, characterized in that: An oil return pipe (7) is also provided on the panel body. The oil return pipe (7) is located at the bottom of the evaporation area (4). The upper end of the oil return pipe (7) is connected to the working medium flow channel at the bottom of the evaporation area (4), and the lower end of the oil return pipe (7) is connected to the working medium outlet (8).

8. The heat collecting plate according to claim 7, characterized in that: The oil return pipe (7) is arranged in an S shape.

9. The heat collecting plate according to claim 7, characterized in that: A flow limiting collection area (6) is also provided at the bottom of the evaporation area (4), and the pipes of the flow limiting collection area (6) are staggered in a sparse and dense manner in the vertical direction; the upper end of the oil return pipe (7) is provided at the bottom of the flow limiting collection area (6).

10. The heat collecting plate according to claim 1 or 2, characterized in that: The heat collecting plate is of a symmetrical structure, comprising two groups of liquid storage areas (2) and evaporation areas (4) arranged in parallel, with a three-way pipe and / or a three-way joint provided between the two groups of liquid storage areas (2) and evaporation areas (4); the working fluid inlets (1) on the two liquid storage areas (2) are arranged opposite to each other and connected via a three-way pipe / three-way joint, and the working fluid outlets (8) at the bottom of the two evaporation areas (4) are arranged opposite to each other and connected via another three-way pipe or three-way joint.

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