CN116033727A - Phase distribution structure of phase-change cooling system - Google Patents
Phase distribution structure of phase-change cooling system Download PDFInfo
- Publication number
- CN116033727A CN116033727A CN202310308636.1A CN202310308636A CN116033727A CN 116033727 A CN116033727 A CN 116033727A CN 202310308636 A CN202310308636 A CN 202310308636A CN 116033727 A CN116033727 A CN 116033727A
- Authority
- CN
- China
- Prior art keywords
- liquid
- pipeline
- evaporator
- liquid level
- phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention relates to the technical field of refrigeration, in particular to a phase distribution structure of a phase change cooling system. Including the one end of condenser is connected to the delivery outlet of evaporimeter upper end through the return air pipeline, and the other end of condenser is connected to the input port of evaporimeter one side through the feed liquor pipeline, connect a driving pump and liquid level control mechanism on the pipeline of feed liquor pipeline, liquid level control mechanism is located the top position of evaporimeter one side, still connects an overflow valve on the pipeline of feed liquor pipeline, and overflow valve one end is connected to on the pipeline of driving pump entrance, the other end is connected to on the pipeline of driving pump exit through the pipeline. The liquid level control mechanism is arranged to keep the gas substances in the phase change cooling system at reasonable positions, so that the high-efficiency operation of the system is ensured, and the cooling efficiency is not affected due to unreasonable phase distribution; the overflow valve overflows redundant flow into the inlet pipeline of the driving pump, so that the pressure of the feed liquid is ensured, and the driving pump is protected from overload damage.
Description
Technical Field
The present disclosure relates to cooling systems, and particularly to a phase distribution structure of a phase change cooling system.
Background
In high power electronics, appliance cooling applications, water cooling has been the dominant source. The heat-transfer device uses cooling water (or liquid) as a heat-transfer medium, absorbs heat at the position of a heating component to raise the temperature, and then flows to a low-temperature end to cool down so as to achieve the purposes of heat transfer and conduction. The heat-generating components also dissipate heat and cool as heat is continuously "carried away".
The phase-change cooling is to utilize the characteristic of a great deal of heat absorption and heat release during the phase change of the material to absorb heat and change phase at the position of the heating component, sublimate the liquid into gas, then convey the gas to a cold source position, and convey the gas to the position of the heating component to absorb heat after the gas is condensed into liquid after releasing heat. Because the phase change heat absorption power is particularly high, the phase change cooling system can complete the heat energy transportation with high power at a small mass flow. Taking water as an example, the heat of about 4.2 kJ can be absorbed per kilogram of water with the temperature of one liter, and the vaporization heat of the phase-change heat exchange material (taking fluorocarbon cooling liquid FCM-47 as an example) can absorb 121.7kJ/kg of heat by changing each kilogram of liquid into gas under the condition of unchanged temperature, which is about 29 times of the same quality of water. Therefore, in contrast to the water cooling efficiency, it is theoretically possible to achieve the water cooling transmission efficiency with only a flow rate of 1/29. By adopting the phase-change cooling mode, the volume of the heat exchange mechanism and the power loss of fluid transportation can be greatly reduced, and the mechanical vibration and the operation noise generated by the phase-change cooling mode can be greatly reduced. Therefore, the method has wide development and application space.
In the system structure, from the distribution of liquid at the heat source, the transportation after phase change into gas, how the gas releases heat and condenses at the cold source, all have the stringent requirements. The freon is taken as a two-phase flow heat exchange working medium for example, and the most perfect state of the freon in the working process is that after the liquid is changed into a gaseous state in an evaporator, the liquid smoothly flows into a condenser by slight pressure difference to condense and release heat. The condensate can smoothly flow together under the self weight, then flows back to the evaporator by self weight and then circulates again.
In the two-phase flow heat exchange system, the working medium is changed into gas by the liquid phase after absorbing heat in the evaporator, and then the gas is released heat and condensed into liquid by the condenser to finish energy movement. Thus, two phases of working fluid, namely, liquid working fluid and gaseous working fluid, are always present in the system. In order to ensure efficient operation of the system, the system must have a reasonable "phase distribution". To store the liquid working medium in the evaporator capable of absorbing heat energy, the liquid working medium must be timely discharged and supplemented after absorbing heat and gasifying so as to ensure that the liquid working medium can receive heat energy in the maximum area. Then, the system only needs to introduce the gas working medium into the condenser to ensure that the gas working medium exchanges heat with the cold source with the largest contact area, and the gas working medium needs to be discharged in time when condensate is generated in the condenser to ensure that the condenser always contacts the cold source with the largest area. Therefore, the structural design of the two-phase flow heat exchange system must ensure reasonable 'phase distribution' to enable the system to be in an optimal working state.
The above situation where the flow and flow rate are just balanced is difficult to maintain, such as load power variations, drift in fluorine pump flow, etc. When the flow rate of the fluorine pump is smaller than the 'circulation rate' of the system, the 'phase distribution' of the system is broken, the liquid of the evaporator is reduced, the upper half part of the heat exchange tube of the evaporator is exposed and dry-burned, the heat exchange efficiency of the evaporator is reduced, the 'circulation rate' of the system is further influenced, and the heat exchange efficiency of the system is reduced. And then, for example, the flow rate of the fluorine pump is increased to enable the liquid level of the evaporator to rise. At this point we see that the "phase profile" of the system is changed because the rate of digestion (evaporation) of the fluorine liquid by the evaporator is less than the flow rate of the fluorine pump, and the excess fluorine liquid floods the upper port of the evaporator and enters the outlet pipe until all the fluorine liquid is pumped by the fluorine pump into the evaporator and the outlet pipe of the evaporator, and the fluorine pump begins to pump air (because the total amount of liquid is limited). Because the outlet pipe is filled with liquid, the gas cannot flow at a design flow rate of 5m/s, resulting in a decrease in the refrigerant gas delivery efficiency. Meanwhile, the gas evaporated in the evaporator is sealed in the evaporator to increase the pressure again, and the pressure also increases the phase change temperature of the fluorine material, so that the logarithmic average temperature difference between the phase change temperature and the heat source temperature is reduced, thereby causing the heat exchange power of the evaporator to be insufficient and reducing the heat exchange efficiency of the system.
In the design of a traditional phase-change cooling system, a driving pump is used for pushing liquid of a phase-change cooling medium, the liquid is pumped to a position of a heating component for absorbing heat, and the liquid supply amount is adjusted according to the requirement of the maximum power of a load. Sometimes, in order to prevent the "dry burning" caused by insufficient liquid supply, a point is added above the required maximum power of the load.
Although the method ensures the supply amount of the phase-change cooling liquid, excessive supply liquid can enter the gas pipeline, and particularly when the load works under a low-power working condition, a large amount of liquid enters the gas pipeline, and after the liquid enters the gas pipeline, the gas circulation is not smooth, so that the transportation efficiency of heat energy is affected. Meanwhile, the gas pressure is also pushed up by the interference of the liquid, the boiling point (phase change point) of the phase change cooling material is sensitive to the pressure, the boiling point of the phase change cooling medium is increased by the increase of the gas pressure (the special characteristic table of the phase change cooling material can be specifically inquired), and the original design of the system is damaged by the increase of the boiling point, so that the cooling effect of the system is further deteriorated.
The working state of the high-power electronic load is not only the high-power electronic load can not work at the maximum power, but also the load power can be changed continuously in the working process, especially in some high-frequency intelligent electronic equipment, the load power is changed in a huge way, namely, a variable flow control method is adopted, and the response speed of the flow change of liquid can not reach the response speed of an electronic level. Many phase-change cooling systems give up flow tracking control and make up for the deficiency by expanding the heat exchange area.
The patent number is 20221041844. X, the invention is a pump driven cavitation self-repairing large-scale two-phase flow cooling system and a method thereof, the system comprises an evaporation cold plate and a condenser of electronic equipment, the evaporation cold plate of the electronic equipment is connected with the condenser, the condenser is connected with a liquid storage tank, a liquid level sensor is arranged in the liquid storage tank, two pipelines are arranged at the bottom of the liquid storage tank and are connected with a liquid supplementing tank, a liquid return one-way valve is arranged on one pipeline, a liquid supplementing one-way valve is arranged on the other pipeline, a refrigerant filling port is arranged between the liquid return one-way valve and the liquid supplementing tank, a liquid supplementing pump is arranged between the liquid supplementing one-way valve and the liquid supplementing tank, and the bottom of the liquid storage tank is connected with a liquid supplying pump which supplies liquid to the evaporation cold plate of the electronic equipment. The invention realizes self-repairing and self-starting after pump cavitation, and improves engineering applicability and reliability of a large two-phase flow cooling system. The patent application only gives a sufficient flow of cooling liquid at the front end of the evaporator at the position of driving the pump, when a certain load suddenly stops, the return air pipeline connected with the evaporator and the condenser can cause pressure problems, and the liquid also floods into the condenser, so that the problem of cavitation generated by the self-repairing fluorine pump because of too small flow is solved.
In the application of a phase-change cooling system, the liquid substance of the phase-change cooling material exists at the place where the liquid substance exists, and the gaseous substance exists at the place where the gaseous substance exists, so that the efficient operation of the system can be ensured. Unreasonable fluid phase distribution is a main reason for influencing the high-efficiency and stable operation of a phase-change cooling system, and is a main factor that the technology cannot be popularized.
Disclosure of Invention
The invention aims to solve the defects, and in the two-phase flow heat exchange system, the working medium is changed into gas by liquid phase change after heat absorption in the evaporator, and then the gas is discharged to the condenser to be condensed into liquid to finish energy movement. Thus, two phases of working fluid, namely, liquid working fluid and gaseous working fluid, are always present in the system. In order to ensure efficient operation of the system, the system must have a reasonable "phase distribution". To store the liquid working medium in the evaporator capable of absorbing heat energy, the liquid working medium must be timely discharged and supplemented after absorbing heat and gasifying so as to ensure that the liquid working medium can receive heat energy in the maximum area. Then, the system only needs to introduce the gas working medium into the condenser to ensure that the gas working medium exchanges heat with the cold source with the largest contact area, and the gas working medium needs to be discharged in time when condensate is generated in the condenser to ensure that the condenser always contacts the cold source with the largest area. Therefore, the structural design of the two-phase flow heat exchange system must ensure reasonable 'phase distribution' to enable the system to be in an optimal working state. To this end, a phase distribution structure of a phase-change cooling system is provided.
In order to overcome the defects in the background art, the technical scheme adopted by the invention for solving the technical problems is as follows: the phase distribution structure of the phase change cooling system comprises a condenser, an evaporator and a driving pump, wherein one end of the condenser is connected to an output port at the upper end of the evaporator through a return air pipeline, the other end of the condenser is connected to an input port at one side of the evaporator through a liquid inlet pipeline, the pipeline of the liquid inlet pipeline is connected with the driving pump and a liquid level control mechanism, the position of the liquid level control mechanism is located at one side of the evaporator, an overflow valve is further connected to the pipeline of the liquid inlet pipeline, one end of the overflow valve is connected to the pipeline at the inlet of the driving pump through a pipeline, and the other end of the overflow valve is connected to the pipeline at the outlet of the driving pump through a pipeline. The structure adopts a liquid level control method to control the dryness of the outlet of the steam part in the evaporator to improve or ensure the efficiency of the phase-change heat exchange system and the problem of mutual interference between loads.
According to another embodiment of the invention, the evaporator is further provided with a high temperature inlet and a low temperature outlet at the other side.
In order to make the evaporator generate more or less gas working medium, the evaporator outputs more or less gas working medium and can timely supplement the same amount of liquid working medium. The condenser can condense the gas working medium, and then all condensate is conveyed to the evaporator without breaking or buckling, so as to achieve balance. For this purpose, according to another embodiment of the present invention, the liquid level control mechanism is further provided with a height lower than the outlet at the upper end of the evaporator, so that the liquid level inside the evaporator is higher than the height of the tube orifice of the upper tube plate inside the evaporator, and the height difference H is 20mm-40mm. Thus, the problems that the upper half part of the heat exchange tube of the evaporator is exposed and dry-burned, the heat exchange efficiency of the evaporator is reduced, and the heat exchange efficiency of the system is reduced due to the influence of the circulation rate of the system are solved, the output of a gas working medium is ensured, the same amount of liquid working medium can be timely supplemented, the quantity of liquid working medium is not too large, the quantity of liquid working medium is not too small, and at least the dry-burned problem can not occur.
In the practical application process, the evaporator is compared with a "pot", the load is compared with a "heat source", the heat generated by the load is continuously input into the evaporator, condensate in the evaporator is heated and evaporated, the gas returns to the condenser, and the generated "heat source" also changes due to the power change of the load, so according to another embodiment of the invention, the evaporator is provided with at least 2 evaporators and is connected in parallel, the input port of each evaporator is connected with the liquid inlet pipeline through the liquid supply pipeline, the liquid level control mechanism is arranged on each liquid supply pipeline, and the output port of each evaporator is connected to the air return pipeline through the air return branch pipe. Each evaporator corresponds to a load, and through the liquid level control mechanism arranged on the liquid supply pipeline of each evaporator, the heat exchange efficiency brought by the change of liability power can be correspondingly ensured, the output of more or less gas working media can be ensured, and meanwhile, the same amount of liquid working media can be timely supplemented.
To adapt to various types of connected load structures, according to another embodiment of the present invention, the evaporators are arranged in an array, each layer is provided with at least 1 evaporator, a liquid level control mechanism is arranged on a liquid inlet pipeline connected at a total inlet of the lower end of each layer of evaporators, the lower ends of the evaporators are connected through pipelines, and the upper end of each layer of evaporators is connected through an air outlet branch pipe and is connected to an air return pipeline.
According to another embodiment of the invention, the liquid level control mechanism further comprises a float chamber, wherein a liquid inlet is formed in one side of the float chamber, a liquid outlet is formed in the bottom of the float chamber, a float and a needle valve seat are arranged in the float chamber, one side of the float is connected with a float arm, the front end of the float arm is connected with a needle valve, the needle valve is positioned in the needle valve seat, and the needle valve seat is connected with the liquid inlet. The structure in the float chamber controls the fluorine liquid amount of the evaporator, when the evaporator is started, working liquid working medium evaporates to reduce, the liquid level drops along with the liquid level, and the float drops along with the liquid level. In the descending process of the floater, the liquid inlet valve is opened, and then liquid working medium starts to be injected under the head pressure of the fluorine pump. Along with the injection of the liquid working medium, the liquid level of the evaporator rises, and meanwhile, the floater is pushed up, and the floater can be linked to close the liquid inlet valve. When the load power of the evaporator is increased and the liquid level is quickly lowered, the opening of the float switch valve is increased, and the fluorine liquid supply is increased. When the power of the evaporator is low and the liquid level is slowly reduced, the opening degree of the float switch valve is reduced, and the fluorine liquid supply is reduced. The liquid inlet valve is automatically opened and closed under the buoyancy action of the floater, so that the evaporator is always at the optimal liquid level. When the flow supplied by the float switch is small, the flow which is excessive by the fluorine pump returns to the liquid inlet pipe through the overflow valve.
When in installation, the float chamber is matched with the evaporator, and is connected by a hose, so that the liquid level height is adjustable.
Therefore, no matter how the load of the internal machine is started, stopped and changed, the evaporator can always keep the working liquid level which is level with the liquid level control mechanism to work, and the internal return air pipeline is always gas. Meanwhile, because the liquid level switch has unidirectionality, the pressure of the steam in the evaporator only can be relieved to the gas phase pipeline, so that the steam is driven to overflow towards the condenser. Likewise, when the flow rate of the float level switch is small or completely turned off, the flow rate of the fluorine pump flows to the fluorine pump supply pipe through the overflow valve. The evaporator is always at the optimal liquid level through the matching of the liquid level control mechanism and the overflow valve.
In order to solve the problem, according to another embodiment of the present invention, an air extraction device is further provided on the air return pipe.
According to another embodiment of the invention, the method further comprises the step of arranging a Tesla valve on the return air pipeline.
The beneficial effects of the invention are as follows:
1. by arranging the liquid level control mechanism, the liquid state substance in the phase-change cooling system is controlled at a reasonable position at the load end, so that the liquid state substance cannot enter the gas pipeline at any time and under any working condition. The gas substances in the phase-change cooling system are kept at reasonable positions, so that the high-efficiency operation of the system is ensured, and the cooling efficiency is not affected due to unreasonable phase distribution;
2. by arranging the liquid level control mechanism, the consumption of the liquid state can be automatically supplemented, the liquid state monitoring device is multipurpose, more and less in supplement, the supply quantity demand of the load to the liquid state substances can be tracked at all times, and the problems of shortage and excessive supply can be completely avoided. Not only solves the problem that the heat exchange efficiency is affected by the liquid substances entering the gas pipeline, but also solves the problem of matching the power and the liquid supply amount;
3. by arranging the overflow valve, the problem that the liquid supply pressure of the driving pump fluctuates due to the start and stop of the liquid supply of the liquid level control mechanism is solved, the overflow valve in the pipeline can overflow redundant flow into the inlet pipeline of the driving pump in a pressure overflow control mode, the liquid supply pressure is ensured, and the driving pump is also protected from overload damage;
4. after the air extractor or the Tesla valve is arranged, the pressure rise of the air return pipeline is restrained, and because the air return pipeline is provided with the air extractor or the Tesla valve, the air return is not driven by the air pressure difference, and after the return power is abundant, the air flow rate design of the pipeline can be greatly improved. When the gas pressure overflows, the flow rate of the gas pipeline can only be selected to be below 5m/s, and after the return air exhaust device or the Tesla valve is arranged, the flow rate of the gas and the pipeline is designed to be 18-20 m/s, so that the diameter of the return air pipeline can be directly reduced to be one fourth of the original diameter. This allows the volume of the return air line, which would otherwise not be advantageous in a two-phase heat exchange, to be improved radically immediately;
5. the Tesla valve is convenient to install, can accelerate the flow of gas, does not consume energy, does not generate motion noise, and has the advantage of no leakage risk.
Drawings
The invention will be further described with reference to the drawings and examples.
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a schematic diagram of the present invention in an array-type multiple load power application;
FIG. 3 is a schematic view of the array evaporator of FIG. 2;
FIG. 4 is a schematic diagram of the present invention in a multiple load power application;
FIG. 5 is a schematic view of the structure of the liquid level control mechanism during liquid injection;
FIG. 6 is a schematic view of the structure of the liquid level control mechanism when liquid injection is stopped;
FIG. 7 is a schematic view of the structure of the invention in which an air extraction device is arranged on the air return pipeline;
FIG. 8 is a schematic diagram of the present invention with a Tesla valve in the return air line;
wherein: 1. the pump, 2, liquid inlet pipe, 3, overflow valve, 4, low temperature outlet, 5, high temperature inlet, 6, evaporator, 7, liquid level control mechanism, 8, return pipe, 9, gas, 10, condenser, 11, liquid supply branch pipe, 12, return branch pipe, 13, float chamber, 14, float, 15, liquid outlet, 16, needle valve, 17, liquid inlet, 18, needle valve seat, 19, float arm, 20, air extractor, 21, tesla valve, 22, air outlet branch pipe, 23, air outlet manifold gas, 24, air outlet branch pipe gas, 25, upper gas, 26, liquid level line, 27, lower liquid, 28, upper pipe orifice.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. Embodiments of the invention are described herein in terms of various specific embodiments, including those that are apparent to those of ordinary skill in the art and all that come within the scope of the invention.
The liquid phase distribution of the phase change cooling system adopts a liquid isolation means, and liquid substances in the phase change cooling system are controlled at a reasonable position at the evaporator end, so that the liquid substances cannot enter a gas pipeline at any time and under any working condition. The gas substances in the phase-change cooling system are kept at reasonable positions, so that the efficient operation of the system is ensured, and the cooling efficiency is not affected due to unreasonable phase distribution.
Meanwhile, the consumption of the tracking load to the liquid state can be automatically supplemented, the system is multipurpose, more and less, less and more, the supply quantity demand of the load to the liquid state material can be tracked at all times, and the problems of shortage and excessive supply can be completely avoided. Not only solves the problem that the heat exchange efficiency is affected by the liquid substances entering the gas pipeline, but also solves the problem of matching the power and the liquid supply amount.
The specific structure is as shown in fig. 1, the device comprises a condenser 10, an evaporator 6 and a driving pump 1, one end of the condenser 10 is connected to an output port at the upper end of the evaporator 6 through a return air pipeline 8, the other end of the condenser 10 is connected to an input port at one side of the evaporator 6 through a liquid inlet pipeline 2, the driving pump 1 and a liquid level control mechanism 7 are connected to the pipeline of the liquid inlet pipeline 2, the liquid level control mechanism 7 is located at the upper position at one side of the evaporator 6, an overflow valve 3 is further connected to the pipeline of the liquid inlet pipeline 2, one end of the overflow valve 3 is connected to the pipeline at the inlet of the driving pump 1 through a pipeline, and the other end of the overflow valve 3 is connected to the pipeline at the outlet of the driving pump 1 through a pipeline. The driving pump 1 pumps the phase change cooling liquid into the liquid inlet pipe 2 and through the liquid level control mechanism 7 into the evaporator 6, where the phase change cooling liquid is controlled at a fixed liquid level by the liquid level control mechanism 7. The liquid level control mechanism 7 and the lower end of the evaporator 6 are of a connector structure, and the liquid level of the liquid level control mechanism 7 is the same as the liquid level of the evaporator 6, namely the optimal working liquid level of the evaporator 6. When the system works, a high-temperature medium flows into the evaporator 6 from the high-temperature inlet 5 and heats the phase-change cooling liquid to make the phase-change cooling liquid be boiled and changed into gas, and the gas enters the condenser 10 through the air return pipeline 8 to be condensed into liquid and then flows back to the inlet of the driving pump 1 for recycling.
The evaporator 6 does not work at the maximum power according to the high-power electronic load or the mechanical equipment load, and the load power can be changed continuously in the working process, so that the internal input liquid amount of the evaporator is changed continuously, particularly in certain high-frequency intelligent electronic equipment, the load power is changed continuously, the liquid supply of the liquid level control mechanism 7 is started and stopped, so that the liquid supply pressure of the driving pump 1 fluctuates, at the moment, the overflow valve 3 in the pipeline can overflow the redundant flow into the inlet pipeline of the driving pump in a pressure overflow control mode, the liquid supply pressure is ensured, and the driving pump 1 is protected from overload damage.
The other side of the evaporator 6 is preferably provided with a high temperature inlet 5 and a low temperature outlet 4, wherein the high temperature inlet and the low temperature inlet can be liquid or high temperature wind blown by a fan, and in short, the high temperature inlet 5 and the low temperature outlet 4 are circulation ports for converting high temperature medium and low temperature medium.
In a preferred embodiment, the liquid level control mechanism 7 is arranged at a height lower than the output port at the upper end of the evaporator 6, so that the liquid level inside the evaporator 6 is higher than the height of the pipe orifice of the upper pipe plate 28 inside the evaporator 6, and the height difference H is 20mm-40mm. As shown in FIG. 1, the liquid level control mechanism 7 is arranged on one side of the evaporator 6, and the distance from the pipe orifice of the upper pipe plate in the evaporator 6 to the liquid level controlled by the liquid level control mechanism 7 is 30mm. The liquid substance in the phase-change cooling system can be controlled at a reasonable position at the evaporator end by the arrangement, so that the liquid substance cannot enter the gas pipeline at any time and under any working condition. The gas substances in the phase-change cooling system are kept at reasonable positions, so that the efficient operation of the system is ensured, and the cooling efficiency is not affected due to unreasonable phase distribution.
The liquid level control mechanism 7 is directly connected to the liquid inlet pipe 2 when connected, and the liquid inlet pipe 2 is an iron pipe or a hard plastic pipe and is positioned at one side of the evaporator 6 through the liquid inlet pipe 2.
The liquid level control mechanism 7 comprises a float chamber 13, a liquid inlet 17 is formed in one side of the float chamber 13, a liquid outlet 15 is formed in the bottom of the float chamber, a float 14 and a needle valve seat 18 are arranged in the float chamber 13, one side of the float 14 is connected with a float arm 19, the front end of the float arm 19 is connected with a needle valve 16, the needle valve 16 is positioned in the needle valve seat 18, the needle valve seat 18 is connected with the liquid inlet 17, and the liquid inlet 17 can be connected with the liquid inlet pipeline 2 through a hose or can be directly connected with the liquid inlet pipeline 2. As shown in fig. 5, when the float 14 in the float chamber 13 does not reach the optimal operating level of the evaporator 6, the needle valve 16 is not closed in the needle seat 18, and the liquid is continuously injected; as shown in fig. 6, when the float 14 in the float chamber 13 reaches the optimum operating level of the evaporator 6, the needle valve 16 is closed in the needle valve seat 18 by the pushing of the float arm 19, and the injection of the liquid is stopped, so that the liquid level in the evaporator 6 is always maintained at the optimum operating level.
When the load power is high, the liquid level of the evaporator drops quickly, the float of the liquid level control mechanism 7 is linked with the opening degree of the needle valve 16 to be high, and the liquid inlet flow is high at the moment. When the load power is low, the liquid level of the evaporator drops slowly, the float of the liquid level control mechanism 7 is linked with the small opening of the valve, and the liquid inlet flow is small at the moment, so that the liquid level control mechanism can automatically change along with the load. If the instantaneous high-frequency loaded high-power electronic product exchanges heat, the heat exchange efficiency is hardly affected as long as the liquid level of the evaporator is not consumed to the dry-heating position because the liquid level of the evaporator is allowed to reasonably fluctuate.
When the pipe network of a plurality of load branches is used, the flow interaction among the load branches can be completely isolated by only adding a set of liquid level control mechanism 7 to each load branch.
When the loaded branches are in a low-power state, the fluorine pump bypasses the excessive flow in a pressure overflow mode, so that the excessive flow is shunted while the pressure of the supply liquid is ensured. In this way, the liquid supply problem of the complex pipe network is solved, and the flow interference among load branches is also solved.
Working principle: when the high-temperature medium flows into the evaporator 6 from the high-temperature inlet 5, the phase-change cooling liquid in the evaporator 6 starts to boil into gas, which is introduced into the cooler 10 through the return air pipe 8. The liquid level in the evaporator 6 starts to drop, the liquid level in the liquid level control mechanism 7 is linked to drop, and the liquid level control mechanism 7 starts to start liquid supply until the liquid level rises to a specified position and then stops. When the high-temperature medium flows into the evaporator 6 from the high-temperature inlet 5 at a high flow rate, the liquid level control mechanism 7 supplies liquid at a high flow rate. When the high temperature medium stops flowing into the evaporator 6 from the high temperature inlet 5 or flows into the evaporator 6 in a low temperature and low flow state, the liquid level control mechanism 7 stops supplying liquid or supplies liquid in a low flow state. The liquid level in the evaporator 6 is always controlled in a reasonable range (namely, fluctuation exists and is also in a small range), and the stable operation of the system is not affected. Because the liquid supply of the liquid level control mechanism 7 is started and stopped, the fluctuation of the liquid supply pressure of the driving pump 1 can be caused, at the moment, the overflow valve 3 in the pipeline adopts a pressure overflow control mode to overflow redundant flow into the inlet pipeline of the driving pump, the liquid supply pressure is ensured, and the driving pump 1 is also protected from overload damage.
In practical application, parallel multi-load concentrated phase-change cooling is often required, and the flow requirement of each load is different due to different distances, different power sizes, different structural states and the like of each load. In the use process, the starting and stopping beats and the power size adjustment of a plurality of loads are often different, the loads are opened and closed, the loads are fully loaded and lightly loaded, the power is stable and unchanged, and the loads are required to be adjusted frequently (even high-frequency power change). Therefore, in a load branch without starting or in a load branch with too small power adjustment, a large amount of non-phase-change cooling liquid directly enters the air return pipeline, so that the pipeline designed at the gas flow rate is enabled, and the normal flow rate of the gas in the pipeline is influenced due to the large amount of liquid entering, so that the bad phenomenon of overlarge exhaust resistance is caused to the branch which works normally. The above problems are solved by providing a liquid level control mechanism 7, the liquid level control mechanism 7 can prevent the liquid level of the phase-change cooling material liquid from exceeding the air outlet at any time according to the structural characteristics of the load, so as to prevent the liquid from entering the outlet pipeline. Specific multi-load structures are described in embodiments one and two.
In a first embodiment, in an application where the array multi-load power is identical, as shown in fig. 2 and 3:
the evaporator 6 is arranged in an array, at least 1 evaporator 6 is arranged on each layer, under the control of a liquid level control mechanism 7, the evaporator 6 forms upper gas 25 and lower liquid 27 in the evaporator 6, a liquid level line 26 is flush with the position of the liquid level control mechanism 7, 3 evaporators 6 are arranged on each layer in fig. 2 and 3, the liquid level control mechanism 7 is arranged on a liquid inlet pipeline 2 connected with the main inlet of the lower end of each layer of evaporators, the evaporators of each layer are connected through pipelines, the upper end of each layer of evaporators 6 is connected with an outlet branch pipe 22 and connected with an air return pipeline 8, the outlet branch pipe 22 of each layer collects the outlet branch pipe gas 24 of the layer, the outlet branch pipe gas 24 of each layer is collected into the air return pipeline 8 again to form an outlet manifold gas 23, one end of the condenser 10 is connected with the output port of the upper end of each layer of evaporators through the air return pipeline 8, the other end of the condenser 10 is connected with the input port of one side of each layer of evaporators through the liquid inlet pipeline 2, the upper end of the liquid inlet pipeline 2 is connected with the overflow valve 3 through the overflow valve 1, and the upper end of the overflow valve 1 is connected with the overflow valve 1 through the overflow valve.
The pump 1 is driven to enable phase-change cooling liquid to enter each evaporator 6 in the array evaporator through the liquid inlet pipeline 2, and according to the structural characteristics of the array evaporator of the system, a set of liquid level control mechanisms 7 are respectively arranged on the liquid inlet pipelines of each layer (which are distinguished according to the height), and the liquid level control mechanisms 7 can control the liquid level entering each layer of the array evaporator so that the liquid level does not exceed the outlet of any load, and the liquid is prevented from entering the outlet pipeline.
When the evaporator 6 in the array evaporator starts to work, the phase change cooling liquid of the load starts to boil to generate consumption, and meanwhile, the liquid level is triggered to drop, at the moment, the liquid supplementing action of the liquid level control mechanism 7 is triggered, and the liquid level control mechanism 7 stops the liquid supplementing action after the liquid level is supplemented and the liquid level rises to the highest limit.
Since the flow rate of the liquid entering each evaporator, i.e., the amount consumed by the load, the load which is not started and the load which is low in power, is small, the total liquid supply amount of the driving pump 1 cannot be consumed entirely, and the excessive flow rate overflows from the overflow valve 3. The overflow valve 3 adopts a pressure overflow mode, and only when the pressure is increased due to insufficient flow consumption, an overflow phenomenon can be generated, so that the liquid supply requirements of all loads are ensured.
In a second embodiment, for applications with completely different multi-load power, as shown in fig. 4:
in the figure, a phase change cooling system with a set of cooling mechanism is centralized for a plurality of large loads in a parallel mode, 6 evaporators 6 are shown, the evaporators 6 are arranged to be connected in parallel, a high-low position is adopted, the input port of each evaporator 6 is connected with a liquid inlet pipeline 2 through a liquid supply branch pipe 11, a liquid level control mechanism 7 is arranged on each liquid supply branch pipe 11, and the output port of each evaporator 6 is connected to a return air pipeline 8 through a return air branch pipe 12.
The pump 1 is driven to serve as a liquid supply master pump, and the phase-change cooling liquid enters three sets of high-level evaporators and three sets of low-level evaporators through the liquid inlet pipeline 2. In each load, a set of liquid level control mechanism 7 is arranged according to the structural requirement of the phase change evaporator of the load. The level control mechanism 7 may, depending on the constructional features of the load, prevent the level of the phase change cooling material liquid from exceeding the air outlet at any time, so as to prevent the liquid from entering the outlet conduit. Thereby ensuring that only gas flows in the return air branch pipe 12 and ensuring that the return air dryness in the return air pipeline 8 is never permeated by liquid.
Similarly, the liquid flow entering each load is the consumption of the load, the load which is not started and the load with low power, and the entering flow is small. When the amount of liquid supplied to drive the pump 1 is not completely consumed, excessive flow flows back to the condenser 10 from the overflow valve 3. The overflow valve 3 adopts a pressure overflow mode, and only when the pressure is increased due to insufficient flow consumption, an overflow phenomenon can be generated, so that the liquid supply requirements of all loads are ensured.
Embodiment three, as shown in fig. 7:
through the liquid level control device at the liquid inlet, the improvement of the dryness of the evaporator outlet of each load branch is ensured by an important technology, and the air extractor 20 can be arranged on the air return pipeline 8 of the two-phase heat exchange main machine, so that the problem that if the structure of the air return main pipe is complex in practical application, especially if the air return main pipe is bent downwards in a U-shaped manner, the extra condensing phenomenon like 'out-of-womb' cannot occur in the U-shaped bend is difficult to ensure. The phenomenon that the air return main pipe is blocked and sealed by liquid is avoided. The gas reflux after the cooling liquid is evaporated can be ensured while the heat preservation of the pipeline of the air return pipeline 8 is well performed and no midway condensation phenomenon occurs.
After the air return pipe is provided with the air extractor, the pressure rise of the air return main pipe is restrained, so that the problem of air pressure rise generated by the air return main pipe is completely solved.
Fourth embodiment, as shown in fig. 8:
the Tesla valve 21 can be arranged on the air return pipeline 8, and the Tesla valve 21 can accelerate the flow of the air, and has the advantages of no energy consumption, no movement noise, no leakage risk and the like. The tesla valve 21 is installed clockwise when installed.
After the air extractor 20 or the Tesla valve 21 is arranged on the air return pipe, the pressure rise of the air return pipeline 8 is restrained, because the air return pipeline 8 is provided with the air extractor 20 or the Tesla valve 21, the air return flow is not driven by the air pressure difference, and the air flow rate design of the pipeline can be greatly improved after the return power is full. The flow rate of the gas pipeline in the gas pressure overflow design can only be selected to be below 5m/s, and after the return air extraction device 20 or the Tesla valve 21 is arranged, the design of the flow rate of the gas and the pipeline is dared to adopt 18 m/s-20 m/s, so that the diameter of the return air pipeline can be directly reduced to be one fourth of the original diameter. This gives a substantial improvement in return line volume that would otherwise not be advantageous in a two-phase heat exchange.
For the second embodiment, 10 load branches are provided, the 10 load branches are in a parallel state, and according to different load power configurations, 4 load branches of 20kw and 6 load branches of 3.4kw are respectively designed, and the total power is about 100.4kw. Each load branch is provided with an independent evaporator 6 as a heat exchanger for circulating heat absorption of the two-phase heat exchange material. The driving pump 1 is used to drive the two-phase heat exchange material liquid to the evaporator to absorb the heat energy of the electric heating. The level of the liquid in each evaporator was set to be 30mm above the orifice of the upper tube sheet 28 in the evaporator 6 by the position of the liquid level controller 7. Aiming at the parameter setting, the concrete performance under the following working conditions is observed respectively:
table 1 is the rated parameters for each load:
table 2 shows the data generated under various conditions:
as can be seen from table 2:
1. when the load power is adjusted from small to large, the parameters of sequence numbers 1-4 can be seen:
the total power of the load is 36KW, 60KW, 81KW and 100.4KW, the liquid level in each evaporator can be seen from the position of the liquid level in the corresponding evaporator that the cooling liquid in the corresponding evaporator is always kept within 30mm above the pipe orifice of the upper pipe plate, although the consumption of the cooling liquid is gradually increased due to the increase of the power, the corresponding liquid level controller can automatically and gradually increase the opening and closing degree of the cooling liquid according to the liquid level descending degree in the evaporator, the liquid level in the evaporator is always kept at a reasonable position, and the output of the driving pump is 3.2m 3 And/h can meet the requirement of supplying the two-phase heat exchange material liquid when the load is full, the opening degree of the liquid level controller is maximized according to the power increase, the overflow valve starts to slowly stop working, each load branch works normally without mutual influence, and the dryness of outlets of all branches is ensured to be close to 1, namely, hundred percent of gas in the return air pipeline 8 is ensured.
2. From large to small, the load power is adjusted, and the parameter of the serial number 4-1 can be seen:
the total power of the load is respectively 100.4KW, 81KW, 60KW and 36KW, the position of the liquid level in each evaporator can show that the cooling liquid in the corresponding evaporator is always kept within 30mm above the pipe orifice of the upper pipe plate, and the liquid consumption of the two-phase heat exchange material is gradually reduced due to the reduction of the total power, but under the control of the liquid level controller, the corresponding liquid level controller is gradually and slowly closed due to the reduction of the cooling liquid consumption, and the liquid supply amount of the driving pump is kept at 3.2m 3 And/h, the liquid level controller is closed, and excessive cooling liquid overflows to the front end of the driving pump 1 from less to more through the overflow valve to form internal circulation, so that the liquid level in the evaporator is always kept at a reasonable position, and the dryness of all branch outlets is close to 1, namely, one hundred percent of gas in the return air pipeline 8.
3. All loads are fully loaded, from normal flow to large regulated main feed flow:
when the liquid supply amount of the circulating cooling liquid of the driving pump 1 is manually adjusted, the total liquid supply amount is gradually increased, the liquid supply amount of each branch is also increased, but due to the arrangement of the liquid level controller, the cooling liquid in the corresponding evaporator is always kept within 30mm above the pipe orifice of the upper pipe plate from the liquid level position in each evaporator, when the liquid level position in each evaporator reaches 30mm above the pipe orifice of the upper pipe plate, the liquid level controller is closed, excessive cooling liquid overflows to the front end of the driving pump 1 from less to more through the overflow valve to form internal circulation, so that the water level in the evaporator is always kept at a reasonable position, and the dryness of all branch outlets is close to 1, namely, hundred percent of gas in the air return pipeline 8.
Table 3, data generated under two high power loads in suddenly closed load branches:
as can be seen from Table 3, the two high-power loads in the load branch are suddenly closed, the consumption of the cooling liquid in the corresponding evaporator connected to the load branch is suddenly minimized, that is, the injection of the cooling liquid is not needed, and the liquid level controller on the load branch is gradually closed to stop the injection of the cooling liquid, because the liquid supply amount of the driving pump 1 is kept at 3.2m 3 And/h, the redundant cooling liquid at the two closed paths of 20kw load branches overflows to the front end of the driving pump 1 through an overflow valve to form internal circulation, other loads keep the original working state, and the dryness of all branch outlets is close to 1, namely, the air in the return air pipeline 8 is hundred percent.
The above is specific experimental data applied to the simulation test in the second embodiment, and it can be obtained that no matter the power of the load changes from small to large, from large to small, or suddenly stops working, or the industrial quantity of the driving pump is too large, under the design of the liquid level controller and the overflow valve, the cooling liquid in the evaporator can be kept at a proper position, all branches do not interfere with each other, and the dryness of the outlets of the branches is close to 1, that is, the dryness of the outlets of the branches is hundred percent of gas in the air return pipeline 8.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.
Claims (8)
1. The utility model provides a phase distribution structure of phase transition cooling system, includes condenser (10), evaporimeter (6) and driving pump (1), its characterized in that: one end of the condenser (10) is connected to an output port at the upper end of the evaporator (6) through an air return pipeline (8), the other end of the condenser (10) is connected to an input port at one side of the evaporator (6) through a liquid inlet pipeline (2), a driving pump (1) and a liquid level control mechanism (7) for controlling the liquid level height in the evaporator (6) are connected to the pipeline of the liquid inlet pipeline (2), the position of the liquid level control mechanism (7) is located at one side of the evaporator (6), an overflow valve (3) is further connected to the pipeline of the liquid inlet pipeline (2), one end of the overflow valve (3) is connected to the pipeline at the inlet of the driving pump (1) through a pipeline, and the other end of the overflow valve is connected to the pipeline at the outlet of the driving pump (1) through a pipeline.
2. A phase distribution structure of a phase change cooling system according to claim 1, wherein: the other side of the evaporator (6) is provided with a high-temperature inlet (5) and a low-temperature outlet (4).
3. A phase distribution structure of a phase change cooling system according to claim 1, wherein: the liquid level control mechanism (7) is arranged at a height lower than an output port at the upper end of the evaporator (6), so that the liquid level inside the evaporator (6) is higher than the height of a pipe orifice of an upper pipe plate (28) inside the evaporator (6), and the height difference H is 20-40 mm.
4. A phase distribution structure of a phase change cooling system according to claim 1, wherein: the evaporator (6) is provided with at least 2 evaporators and is connected in parallel, the input port of each evaporator (6) is connected with the liquid inlet pipeline (2) through a liquid supply branch pipe (11), a liquid level control mechanism (7) is arranged on each liquid supply branch pipe (11), and the output port of each evaporator (6) is connected to the air return pipeline (8) through an air return branch pipe (12).
5. A phase distribution structure of a phase change cooling system according to claim 1, wherein: the evaporators (6) are arranged in an array, each layer is at least provided with 1 evaporator (6), a liquid level control mechanism (7) is arranged on a liquid inlet pipeline (2) connected with the main inlet of the lower end of each layer of evaporator, the lower ends of the evaporators (6) are connected through pipelines, and the upper ends of the evaporators (6) of each layer are connected through an air outlet branch pipe (22) and are connected to an air return pipeline (8).
6. A phase distribution structure of a phase change cooling system according to claim 1, wherein: the liquid level control mechanism (7) comprises a float chamber (13), a liquid inlet (17) is formed in one side of the float chamber (13), a liquid outlet (15) is formed in the bottom of the float chamber, a float (14) and a needle valve seat (18) are arranged in the float chamber (13), one side of the float (14) is connected with a float arm (19), the front end of the float arm (19) is connected with a needle valve (16), the needle valve (16) is located in the needle valve seat (18), and the needle valve seat (18) is connected with the liquid inlet (17).
7. A phase distribution structure of a phase change cooling system according to claim 1, wherein: an air extracting device (20) is arranged on the air return pipeline (8).
8. A phase distribution structure of a phase change cooling system according to claim 1, wherein: a Tesla valve (21) is arranged on the air return pipeline (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310308636.1A CN116033727B (en) | 2023-03-28 | 2023-03-28 | Phase distribution structure of phase-change cooling system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310308636.1A CN116033727B (en) | 2023-03-28 | 2023-03-28 | Phase distribution structure of phase-change cooling system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116033727A true CN116033727A (en) | 2023-04-28 |
| CN116033727B CN116033727B (en) | 2023-07-25 |
Family
ID=86078094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310308636.1A Active CN116033727B (en) | 2023-03-28 | 2023-03-28 | Phase distribution structure of phase-change cooling system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116033727B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110048676A1 (en) * | 2009-08-28 | 2011-03-03 | Hitachi, Ltd. | Cooling system and electronic apparatus applying the same therein |
| CN212299530U (en) * | 2020-06-01 | 2021-01-05 | 北京市京科伦工程设计研究院有限公司 | Refrigerating system with pressure control device |
| CN114151252A (en) * | 2021-11-19 | 2022-03-08 | 哈尔滨工程大学 | Liquid ammonia phase change cooling type hybrid power heat management system |
-
2023
- 2023-03-28 CN CN202310308636.1A patent/CN116033727B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110048676A1 (en) * | 2009-08-28 | 2011-03-03 | Hitachi, Ltd. | Cooling system and electronic apparatus applying the same therein |
| CN212299530U (en) * | 2020-06-01 | 2021-01-05 | 北京市京科伦工程设计研究院有限公司 | Refrigerating system with pressure control device |
| CN114151252A (en) * | 2021-11-19 | 2022-03-08 | 哈尔滨工程大学 | Liquid ammonia phase change cooling type hybrid power heat management system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116033727B (en) | 2023-07-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207118211U (en) | A kind of data center module condensing units radiant heating system | |
| CN103900251B (en) | Immediately heating water heater | |
| CN113206271A (en) | Immersed cooling system and method for fuel cell | |
| CN210832593U (en) | Refrigerating system | |
| CN113784582B (en) | Pump-driven two-phase liquid cooling system for realizing stable flow distribution and flow control method | |
| CN102759159A (en) | Heat pipe and heat pump composite system | |
| CN114071972A (en) | Pump-driving double-loop heat pipe combined heat dissipation system for high-power-density cabinet | |
| CN102297512A (en) | Cascade type heat pump system | |
| CN116033727B (en) | Phase distribution structure of phase-change cooling system | |
| WO2023236596A1 (en) | Computing device, node, and management and control apparatus based on phase-change immersion liquid-cooling system | |
| CN105890211B (en) | A kind of accumulation of energy interconnection heat pump system of suitable cold district heat supply | |
| CN201163095Y (en) | Heat pump water heater equipped with bypass condensation heat exchange loop | |
| KR102513802B1 (en) | Refrigeration system | |
| CN110986400B (en) | Underground energy storage system with double liquid storage cavity structure and control method thereof | |
| CN100547334C (en) | Two-way heat transfer heat pipe | |
| CN113778205A (en) | Multi-connection forced two-phase immersed liquid cooling system and control method thereof | |
| CN202675513U (en) | Heat pipe and heat pump combined system | |
| CN215176142U (en) | Heat pump energy-saving system | |
| CN101586892B (en) | Synchronous refrigerating-heating machine set with cold-hot source complement | |
| CN220674233U (en) | Liquid cooling system for data center | |
| CN104567096A (en) | Heat exchange unit of water chilling and warming machine and operating method thereof | |
| JP7396725B1 (en) | Heat pump system and heat pump system control method | |
| CN219181965U (en) | Heat radiation system of power module | |
| CN214672696U (en) | Immersed cooling system for fuel cell | |
| CN215275782U (en) | System for utilize heat pump set cold and hot volume to carry out concentrated decrement of industry solution |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |