CN115373201A - LCD projector sealing optical machine with indirect liquid cooling - Google Patents

Abstract

The invention discloses an indirect liquid-cooled sealed optical machine of an LCD projector, which comprises a cooling system, an optical system and an optical machine housing; Heater, water tank and flowmeter, the cooling system also includes an external fan and an internal circulation fan; the water pump, the internal circulation heat exchanger, the light source heat absorber, the water tank and the flowmeter are connected in series Connected into a loop to form a closed loop flow channel. The inside of the closed circulation channel is filled with coolant; the external fan is blowing or sucking air to the water tank. The thermal equilibrium point of heat generation and heat dissipation of the present invention and the temperature difference between the environment are small, and the temperature rise of the LCD light valve and the optical material is small, which is beneficial to significantly improve the heat dissipation capacity of the optical machine, prolong the service life of the product, and allow the projector to output higher brightness at the same time , Enhance the overall market competitiveness of the product.

Description

An indirect liquid-cooled LCD projector sealed light engine

technical field

The invention relates to the field of projectors, in particular to an indirect liquid-cooled LCD projector sealed light engine.

Background technique

The fully sealed LCD projector light engine (referred to as the light engine, the same below) is a relatively popular structure in the industry in recent years. Since the heat dissipation of the LCD light valve is generally air-cooled, after sealing the optical system, it is significantly reduced. The life of the optical device can be significantly improved by eliminating the failure trouble caused by the deposition of dust on the surface of the optical device.

The specific structure is to set a closed circulation air duct (commonly known as "inner circulation air duct" in the industry) inside the optical machine, and the inner circulation air duct and the external atmosphere have certain airtightness. It also includes an internal circulation fan, an internal circulation heat exchanger (referred to as a heat exchanger, the same hereinafter) and the like. Put the LCD light valve, internal circulation fan and heat exchanger in the internal circulation air duct, and through the operation of the internal circulation fan, the heat on the surface of the LCD light valve can be taken away theoretically, and through the heat exchanger, the air inside the light machine The heat is transferred and diffused into the atmosphere. The heat source or priority heat dissipation object inside the optical machine is mainly the LCD light valve, and the cooling of the internal air mainly depends on the heat exchanger.

Under the current technical conditions, domestic LCD projectors have passed the 400Lm (lumen) mark. Due to the extremely low transmittance of the LCD light valve (natural light is about 5%-6%), and if the sealed optical machine technology is used, For example, the optical power corresponding to the output of 400Lm generates heat inside the optical machine (mainly the LCD light valve). The existing gas/air heat exchanger technology for the optical machine, see Figure 8-Figure 11 (described later), is aimed at about 3- As far as the 5-inch LCD light valve is concerned, it is almost impossible to provide effective heat dissipation for the LCD light valve. Even under the premise of relaxing the noise and volume indicators to a certain extent. The key reason is that the heat transfer from the heat absorbing part of the heat exchanger to the heat releasing part such as b' in Figure 8 requires a huge temperature difference, and usually the temperature difference is ≥ 30°C, which seriously affects the heat dissipation of the optical machine.

The above-mentioned key factor that causes the optical machine to not effectively dissipate heat is that the heat dissipation efficiency of the existing optical machine is affected by various objective factors that restrict each other, and it has been difficult to obtain a breakthrough. The fundamental reason is the heat transfer coefficient of the internal circulation air duct (to a certain extent, it can It is understood as the heat transfer coefficient) has been limited by the current technical conditions or the product definition of a single LCD projector.

Because after the optical machine tends to the thermal equilibrium state, the internal air temperature is as high as 60°C or more. At this time, the main materials such as the LCD light valve, polarizer, Philippine mirror and optical machine housing (usually plastic) of the projector are much higher than that of the projector. 60°C, usually as high as ≥85°C-110°C, it has already burned or failed. For the heat dissipation of the optical machine, the smaller the difference between the temperature value of the thermal balance point and the ambient temperature, the better the quality of the product, and the more advanced and reliable the optical machine heat dissipation technology. Therefore, the present invention provides an indirect liquid-cooled LCD projector sealed light engine, the heat balance point of heat generation and heat dissipation and the temperature difference between the environment are small, and the ability to transfer heat is cascaded with the temperature of each heat source ("thermal cascade", the same as the following) ) effect is far superior to the existing air-cooling technology, and the comprehensive engineering adaptability is far superior to the existing air/air heat exchange technology and even the active refrigeration technology such as the use of cold pumps, which is conducive to significantly improving the heat dissipation capacity of the optical machine.

Contents of the invention

The object of the present invention is to overcome the deficiencies of the prior art and provide an indirect liquid-cooled LCD projector sealed light engine. The sealed optical mechanism of the indirect liquid-cooled LCD projector of the present invention is relatively simple to manufacture, high in cost performance, and the thermal balance point of heat generation and heat dissipation and the temperature difference between the environment are small, and the ability to transfer heat is cascaded with the temperature of each heat source ("thermal cascade", the same hereinafter) The effects are far superior to the existing air-cooling technology, and the comprehensive engineering adaptability is far superior to the existing air/air heat exchange technology and even active refrigeration technologies such as cold pumps. The temperature rise of the LCD light valve and optical materials is small, which is conducive to significant Improve the heat dissipation capacity of the optical machine, prolong the service life of the product, and at the same time allow the projector to output higher brightness, and enhance the overall market competitiveness of the product.

To achieve the above object, the present invention provides an indirect liquid-cooled LCD projector sealed optical engine, including a cooling system, an optical system and an optical engine housing.

The cooling system includes a water pump, an internal circulation heat exchanger, a light source heat absorber, a water tank and a flow meter arranged in sequence according to the liquid flow direction; the cooling system also includes an external fan and an internal circulation fan.

The water pump, the internal circulation heat exchanger, the light source heat absorber, the water tank and the flowmeter are all provided with a water inlet and a water outlet, and the water pump, the internal circulation heat exchanger, The light source heat absorber, the water tank and the flow meter are connected in series to form a loop, forming a closed circulation flow path. The inside of the closed circulation channel is filled with cooling liquid. The external fan is blowing or sucking air to the water tank.

Further, the number of the water pump, the internal circulation heat exchanger, the water tank, the external fan and the internal circulation fan is one or more.

When there are multiple water pumps, internal circulation heat exchangers and water tanks, they are connected in series or in parallel to the cooling system.

Further, the optical system includes an LED light source, a light collector, a collimator lens, an LCD light valve, a field lens, an imaging mirror and a projection lens arranged in sequence according to the traveling direction of light. The light source heat absorber is attached to the back of the LED light source.

One end of the light engine housing is provided with a light source installation port, and the other end is provided with a lens installation port; the LED light source and the projection lens are respectively installed at the light source installation port and the lens installation port correspondingly.

The condenser, the collimating lens, the LCD light valve, the field lens, the imaging mirror, the internal circulation heat exchanger and the internal circulation fan are installed in the optical machine housing . The water pump, light source heat absorber, water tank, flow meter and external fan are located outside the optical machine housing.

The interior of the optical machine housing is provided with an internal circulation air duct for closed-loop circulation, and the LCD light valve, the internal circulation heat exchanger and the internal circulation fan are placed in the internal circulation air duct; the internal circulation The water inlet and water outlet of the heat exchanger pass through the optical machine housing.

Further, the internal circulation heat exchanger includes a first confluence pipe, a second confluence pipe, several water channels, and several fins; each of the water channels is flat and the outer surface of the flow cross section is rectangular or Round waist shape.

The surface of the fins has a wavy structure.

When the number of the water channels is one less than the number of the fins, two adjacent fins are separated by one of the water channels, and the opposite two outer planes of any one of the water channels are respectively connected to one The crests or troughs of the wavy structure of the fins.

When the number of the water channels is one more than the number of the fins, the crest or trough of the wave-shaped structure of the fins is connected between two adjacent water channels.

The inside of the first confluence pipe is provided with a blocking wall, through which the first confluence pipe is divided into two disconnected cavities; the two disconnected cavities are the water inlet chamber and the water outlet chamber. chamber; the water inlet of the internal circulation heat exchanger communicates with the water inlet chamber, and the water outlet of the internal circulation heat exchanger communicates with the water outlet chamber.

One end of some of the several water channels communicates with the water inlet chamber of the first confluence pipe; one end of the remaining part of the several water channels communicates with the water outlet chamber of the first confluence pipe. The opposite ends of several water channels communicate with the second confluence pipe;

The cooling liquid flows into the water inlet cavity of the first confluence pipe through the water inlet of the internal circulation heat exchanger, is divided through the water inlet cavity, and then flows to the first water channel through some of the water channels. The two confluence pipes merge, and further flow back to the water outlet chamber of the first confluence pipe through the remaining part of the several water channels, and flow out through the water outlet of the internal circulation heat exchanger.

Further, the internal circulation heat exchanger also includes a skeleton; the first confluence pipe, the second confluence pipe, several water channels and several fins are assembled and installed inside the skeleton.

Preferably, the water pump, the internal circulation heat exchanger, the light source heat absorber, the water tank and the flow meter are connected in series through water pipes, and the water pipes are made of environmentally friendly silicone tubes.

Positive effect of the present invention:

1. The cooling system of the present invention forms a closed circulation flow channel, and the circulation of the cooling liquid in the cooling system is realized through the water pump, so that the internal circulation heat exchanger can effectively and quickly absorb the heat in the optical system, and realize the rapid heat dissipation of the LCD light valve; and the light source The heat sink can effectively and quickly absorb the heat emitted by the LED light source to achieve effective and rapid heat dissipation of the LED light source. At the same time, the external fan is blowing or sucking air to the water tank to realize rapid heat dissipation of the coolant in the water tank and ensure the cooling effect of the cooling system. . The invention is relatively simple to manufacture, high in cost performance, small in thermal balance point of heat generation and heat dissipation and ambient temperature difference, heat transfer capability and temperature cascade effect of each heat source ("thermal cascade", the same hereinafter) effect are far superior to the existing air cooling technology , the comprehensive engineering adaptability is much better than the existing air/air heat exchange technology or even active refrigeration technology such as cold pump, the temperature rise of LCD light valve and optical material is small, which is conducive to significantly improving the heat dissipation capacity of the optical machine and prolonging the service life of the product At the same time, the projector also allows to output higher brightness, which improves the comprehensive competitiveness of the product in the market.

2. Compared with the prior art, it is only aimed at setting a heat exchanger (gas/gas heat exchange) with a gas (heat absorption)/conduction (baffle)/gas (heat release) structure on the internal circulation air duct of the optical machine, or The heat exchanger with gas (heat absorption)/refrigeration/gas (heat release) structure is only aimed at the partial and single-point heat dissipation of the light machine with heat pipe radiators or extruded profile radiators for LED light sources. The heat absorber of the light source and multiple internal circulation heat exchangers, multiple internal circulation fans, multiple water tanks and multiple external fans can be set up to conduct comprehensive and multi-point cooling of the sealed optical machine of the projector, which can effectively reduce heat generation/ The temperature value of the heat balance point of heat dissipation minimizes the temperature rise of each heat source, so that the optical machine has better quality;

3. Compared with the prior art, the cooling (transferring heat) method of the high-consumption and low-efficiency Peltier element is set for the heat exchanger of the internal circulation air duct, and the present invention does not require additional high power for the Peltier element Energy consumption can effectively reduce the input electric power of the projector, save energy and benefit the overall heat dissipation of the projector.

4. Due to the stronger heat removal ability of the liquid, the cascade effect of the heat source temperature at different positions in the indirect liquid cooling system of the present invention is much better than that of the existing air cooling technology.

5. The specific heat capacity of the liquid is much larger than that of the air, which can effectively reduce the temperature change speed of the heating element, which is conducive to significantly improving the reliability of the product, including but not limited to balancing several chips of the LED light source due to the volt/ampere characteristic (or dynamic content) The high temperature of individual chips caused by the difference in resistance) is beneficial to prolong the life of chips that "grab power".

6. In addition to obtaining different heat dissipation effects by adjusting the speed of each fan in the prior art, the present invention can also realize the change of the heat transfer speed of the cooling system by adjusting the speed of the water pump, so that the cooling system of the projector can work more scientifically and efficiently status.

7. Compared with the existing heat exchanger technology, the internal circulation heat exchanger of the present invention has a much higher heat exchange area per unit volume (m ² /m ³ ), which is used for the miniaturization of the sealed optical machine of the projector, or for the internal circulation The air duct provides a higher heat transfer coefficient, which plays a significant positive role.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments recorded in the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the schematic diagram of the embodiment of the present invention;

Fig. 2 is another perspective view of the embodiment of the present invention;

Fig. 3 is the optical system figure of the embodiment of the present invention;

Fig. 4 is a display diagram of the embodiment of the present invention with the opener housing;

Fig. 5 is a display diagram of an internal circulation heat exchanger according to an embodiment of the present invention;

Fig. 6 is a partial sectional view of Fig. 5;

Fig. 7 is a further illustration of Fig. 5;

Fig. 8 is a structural schematic diagram of an existing buckle FIN welded heat exchanger;

Fig. 9 is a structural schematic diagram of an existing heat exchanger using heat pipes for heat transfer;

Fig. 10 is a schematic diagram of a heat exchanger of an existing straight rib profile structure;

Fig. 11 is a schematic structural diagram of a conventional heat exchanger using a cold pump.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the present invention. .

It should be noted that like numerals denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

It should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner" and "outer" are Based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that the inventive product is usually placed in use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must Having a particular orientation, being constructed and operating in a particular orientation, and therefore not to be construed as limiting the invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are absolutely horizontal or overhanging, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal than "vertical", and it does not mean that the structure must be completely horizontal, but can be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation", "installation", "connection" and "connection" should be understood in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Example:

Referring to FIG. 1-FIG. 7 , this embodiment provides an indirect liquid-cooled LCD projector with a sealed optical engine, including a cooling system, an optical system and an optical engine housing 3 .

The cooling system includes a water pump 11, an internal circulation heat exchanger 12, a light source heat absorber 13, a water tank 14 and a flow meter 18 arranged in sequence according to the flow direction of the liquid (or cooling liquid, the same hereafter); the cooling system also includes an external Fan 15 and internal circulation fan 16.

The water pump 11 , the internal circulation heat exchanger 12 , the light source heat absorber 13 , the water tank 14 and the flow meter 18 are each provided with a water inlet and a water outlet. The water pump 11, the internal circulation heat exchanger 12, the light source heat absorber 13, the water tank 14 and the flow meter 18 are connected in series to form a closed circulation channel, and the inside of the closed circulation channel Fill with coolant. See the direction shown by the arrow in Figure 1 as the direction of liquid flow.

In this embodiment, the water inlets and outlets on the water pump 11, the internal circulation heat exchanger 12, the light source heat absorber 13, the water tank 14 and the flow meter 18 are preferably but not limited to Pagoda connector. Wherein the inner circulation heat exchanger 12, the light source heat absorber 13, the pagoda joint (water inlet and water outlet) of the water tank 14 are preferably but not limited to corresponding and described first manifold 121 (see later description ), the light source heat absorber 13 and the structural body of the water tank 14 are connected by brazing. The water pump 11 and the flow meter 18 are standard parts, generally plastic casings, so their corresponding water inlets and outlets, and their own structural bodies are often injection molded as one.

In this embodiment, the water pump 11, the internal circulation heat exchanger 12, the light source heat absorber 13, the water tank 14 and the flow meter 18 are connected in pairs by water pipes, and each water inlet and outlet The setting of the water port is used to facilitate the connection of the water pipe. And the multi-section water pipe includes a first water pipe 171 connected between the water outlet of the water pump 11 and the water inlet of the internal circulation heat exchanger 12; connected between the water outlet of the internal circulation heat exchanger 12 and the light source The second water pipe 172 between the water inlet of the heat absorber 13; the third water pipe 173 connected between the water outlet of the light source heat absorber 13 and the water inlet of the water tank 14; The fourth water pipe 174 between the water port and the water inlet of the flow meter 18 ; the fifth water pipe 175 connected between the water outlet of the flow meter 18 and the water inlet of the water pump 11 . In this embodiment, considering the actual conditions of the projector such as environmental protection, power consumption, weather resistance and volume, the inner diameter of the water pipe is preferably but not limited to 6mm-8mm to better meet the technical requirements, and the material of the water pipe is preferably environmentally friendly. High-quality silicone tubes, so that for consumers, the pipes will not emit peculiar smells, increasing consumer experience satisfaction. At the same time, the position of the flow meter 18 can be installed before or after the water pump 11, without limitation, and the functions are similar.

According to the flow direction of the coolant, the water pump 11, the first water pipe 171, the internal circulation heat exchanger 12, the second water pipe 172, the light source heat absorber 13, the third water pipe 173, The water tank 14 , the fourth water pipe 174 , the flow meter 18 and the fifth water pipe 175 are filled with coolant. In this embodiment, the coolant is preferably but not limited to an automobile antifreeze, such as the FD-2 automobile antifreeze of Great Wall Company.

The external fan 15 is blowing or sucking air to the water tank 14 . In this embodiment, the external fan 15 is blowing air to the water tank 14 . The size of the external fan 15 is preferably but not limited to an axial flow fan of 120mm*120mm*25mm (standard part model 12025); the water tank 14 is preferably but not limited to a computer water cooling radiator of 120mm*120mm*30mm.

In this embodiment, the structure of the light source heat absorber 13 can refer to the computer water cooling head of 40mm*40mm*12mm. The screw hole of the light source 21. These are the basic common sense of the structure of the projector, so I won't repeat them here.

The number of the water pump 11, the internal circulation heat exchanger 12, the water tank 14, the external fan 15 and the internal circulation fan 16 is one or more; in this embodiment, the water pump 11, the The number of the internal circulation heat exchanger 12, the water tank 14, and the external fan 15 is preferably but not limited to one, and the number of the internal circulation fan 16 is preferably but not limited to two, and the model is preferably but not limited to 5020 The turbo fan, which just matches the 3.5-5 inch LCD light valve.

When the number of the water pump 11, the internal circulation heat exchanger 12, and the water tank 14 is multiple, they are connected to the cooling system in series or in parallel. These are the basic common sense of water and electricity in life, and will not be repeated here. .

Referring to Fig. 3, the optical system described in this embodiment includes an LED light source 21, a concentrator 22, a collimator lens 23, an LCD light valve 24, a field lens 25, an imaging mirror 26 and a projection lens arranged in sequence according to the traveling direction of light rays. Lens 27. In this embodiment, the light concentrator 22 is preferably, but not limited to, a square conical light concentrator (commonly known as "light bucket", "light channel", etc. in the industry). This optical system is the structure adopted by 99% of LCD projectors in the current industry. The light source heat absorber 13 is attached to the back of the LED light source 21 . In this embodiment, the size of the LCD light valve 24 is 4.5 inches, which can perfectly match two 5020 turbo fans.

One end of the optical machine housing 3 is provided with a light source installation port, and the other end is provided with a lens installation port; the LED light source 21 and the projection lens 27 are respectively installed in the light source installation port and the lens installation port correspondingly At the place, the optical machine is fully sealed.

The condenser 22, the collimating lens 23, the LCD light valve 24, the field lens 25, the imaging mirror 26, the internal circulation heat exchanger 12 and the internal circulation fan 16 are installed Inside the optomechanical housing 3 . The water pump 11 , the light source heat absorber 13 , the water tank 14 , the flow meter 18 and the external fan 15 are located outside the optical machine housing 3 .

Referring to Fig. 4, the inside of the optical machine housing 3 is provided with a closed-loop internal circulation air duct 311, and the LCD light valve 24, the internal circulation heat exchanger 12 and the internal circulation fan 16 are placed In the internal circulation air duct 311; the wind flow flowing inside the internal circulation air duct 311 (refer to the arrow of "311" in the figure to indicate), flows out from the air outlet of the internal circulation fan 16 (two installed side by side), After the LCD light valve 24 is cooled (heat dissipation), the air temperature rises, and further hot air passes through the internal circulation heat exchanger 12 and is cooled and returns to the air inlet of the internal circulation fan 16; The water inlet and water outlet of the heater 12 pass through the optical machine housing 3 so as to connect the first water pipe 171 and the second water pipe 172 . This internal circulation air duct 311 is a typical structure of a fully sealed optical machine in the industry at present, and its principle and basic structure will not be repeated here.

5-7, the internal circulation heat exchanger 12 includes a first confluence pipe 121, a second confluence pipe 122, several water channels 123, and several fins 124; each of the water channels is flat and passes through The outer surface of the flow cross-section is rectangular or waist-circular in shape.

The surface of the fins 124 has a corrugated structure. This fin structure is very common in such as engine radiators (water tanks) of automobiles and external units of air conditioners. It has extremely low wind resistance and will not be repeated here.

When the number of the water channels 123 is one less than the number of the fins 124, the adjacent fins 124 are separated by one of the water channels 123, and the opposite two outer sides of any one of the water channels 123 The planes are respectively connected to the crests or troughs of the corrugated structure of one fin 124 .

When the number of the water channels 123 is one more than the number of the fins 124 , two adjacent water channels 123 are connected to the crests or troughs of the wavy structure of the fins 124 .

Referring to FIG. 7 , in this embodiment, the number of water channels 123 is preferably but not limited to six, and the number of fins 124 is preferably but not limited to five.

Continuing to refer to FIG. 7, the inside of the first confluence pipe 121 is provided with a blocking wall 1210, and the first confluence pipe 121 is divided into two disconnected cavities through the blocking wall 1210, that is, the water inlet Chamber 1211 and water outlet chamber 1212; the water inlet of the internal circulation heat exchanger 12 communicates with the water inlet chamber 1211, and the water outlet of the internal circulation heat exchanger 12 communicates with the water outlet chamber 1212.

One end of some of the water channels 123 (preferably but not limited to three in this embodiment) among the several water channels 123 communicates with the water inlet chamber 1211 of the first confluence pipe 121; the remaining parts of the several water channels 123 One end of the water channels 123 (in this embodiment, preferably but not limited to three remaining) communicates with the water outlet cavity 1212 of the first confluence pipe 121 . The other ends of the plurality of water channels 123 communicate with the second confluence pipe 122 .

The cooling liquid flows into the water inlet chamber 1211 of the first confluence pipe 121 through the water inlet of the internal circulation heat exchanger 12 , diverted through the water inlet chamber 1211 , and then passes through some of the water channels 123 123 (such as the aforementioned three) flow to the second confluence pipe 122 for confluence, and further flow back to the outlet water of the first confluence pipe 121 through the remaining part of the water channels 123 (such as the aforementioned three) in the plurality of said water channels 123 The cavity 1212 flows out through the water outlet of the internal circulation heat exchanger 12 .

Specifically, when the hot air in the internal circulation air duct 311 passes through the internal circulation heat exchanger 12 , it passes through the cooling liquid flowing in several water channels 123 to rapidly cool the hot air, and simultaneously passes through several fins 124 to rapidly cool the hot air. Under the combination of several water channels 123 and several fins 124, the internal circulation heat exchanger 12 of this embodiment has a very high heat exchange area per unit volume, which is used for the miniaturization of the projector sealing optical machine, or for the internal circulation air duct 311 provides a higher heat transfer coefficient, which has a significant positive effect.

The internal circulation heat exchanger 12 also includes a skeleton 125; the first confluence pipe 121, the second confluence pipe 122, several water channels 123 and several fins 124 are assembled (such as brazed) and then installed on the The interior of the skeleton 125 is described. The skeleton 125 is used to properly install the internal circulation heat exchanger 12 inside the optical machine housing 3, and prevent damage to the fins during raw material transportation and assembly (because the thickness of the fins is generally only tens of microns).

The flow meter 18 is added to the cooling system to ensure the functional reliability of the system. When failures such as liquid leakage, insufficient pressure, and damage to the water pump 11 occur in the cooling system, the flow meter 18 sends a signal to the main control chip of the projector (the standard configuration of the projector, such as MTK9255, etc.) (not shown in the figure) , to protect the projector from being damaged. At the same time, the flow meter 18 can be used as a flow collection signal to provide intelligently controlled parameter collection input for the main control chip. During specific implementation, it is also possible to choose to add multiple temperature probes (not shown in the figure) on the cooling system, and send them to the main control chip of the projector, and then by adjusting the rotating speed of each blower fan and the rotating speed of the water pump 11, the projector Work in the optimal working condition, increase the intelligence of the cooling system, and bring consumers a better sense of experience.

Refer to Fig. 8-Fig. 11 for the more typical heat exchanger technology of the existing fully sealed optical machine. Fig. 8 is a structural schematic diagram of a heat exchanger adopting buckle FIN welding. In the figure, 41' is a separator, 42' is a heat absorbing part, and 43' is a heat releasing part. The specific manufacturing method is that the heat absorbing part 42' and the heat releasing part 43' of the heat exchanger are continuously punched fin structures (generally "FIN", an industry term) and welded to the two opposite surfaces of the separator 41' , The heat absorbing part 42' is placed inside the optical machine, the heat releasing part 43' is placed outside the optical machine, and the partition 41' isolates the inside and outside of the optical machine to achieve airtightness, which has the advantages of high cost performance and light weight.

The disadvantages of this type of heat exchanger mainly have two aspects. One is that the heat absorbing part 42' absorbs the heat of the air in the internal circulation air duct, and transfers it to the heat releasing part 43' through the partition plate 41'. There is a huge thermal resistance in this process, so that Brings a huge temperature difference, such as the heat of the air in the internal circulation air duct is transferred from a' of the heat-absorbing part 42' in Figure 8 to b' of the heat-releasing part 43' through the partition 41', and the heat is diffused into the atmosphere, The thermal resistance of this process is very large, because the physical distance between a'-b' is long, and the thickness of the buckle FIN is usually ≤0.3mm-0.4mm; secondly, the wind resistance of this buckle FIN structure is relatively large, and the internal circulation The pressure loss of the air flow provided by the fan is extremely large, which further reduces the heat transfer efficiency of the heat exchanger.

Fig. 9 is a structural schematic diagram of an existing heat exchanger using heat pipes for heat transfer. In addition to the relatively large wind resistance of this structure, the heat of the air in the inner circulation air duct is transferred to the heat pipe from the point a" of the heat absorbing part 37' 36', and then transferred from the heat pipe 36' to the point b" of the heat release part 38', the thermal resistance of this process is also extremely large, although the thermal conductivity of the heat pipe 36' is nearly two orders of magnitude that of the partition plate 41' of the scheme in Figure 8, In fact, the heat transfer effects of the schemes in Figure 8 and Figure 9 on specific products are often very different. One is that there is a large temperature difference between the two ends of the heat pipe 36' (at least > 3°C), and the other is that the physical distance between a"-b" is often not shorter than that of the scheme in Figure 8. At the same time, if the heat-absorbing part 37' and the heat release part 38' adopt the buckle FIN structure, and the thickness is usually ≤0.3mm-0.4mm. In addition, the cost of this technical method is also uncompetitive.

Fig. 10 is a schematic diagram of a heat exchanger with a conventional straight-rib profile structure. It is usually composed of two straight-rib profile radiators 47', 48' bonded back to back (some of them simply use aluminum alloy die-casting as a whole). m ² /m ³ ), except that it is suitable for use in some low-brightness (meaning low thermal power) products, it has been phased out.

Fig. 11 is a schematic structural diagram of a conventional heat exchanger using a cold pump. In the figure, 49' is a Peltier element, 50' is a heat absorbing part, and 51' is a heat releasing part. Because this technology will significantly increase the total heat generation of the projector and is still immature in terms of intelligent control, there is no good solution to the phenomenon of condensation, so the industry has been more cautious, and there are few products equipped with this technology.

Continuing to refer to Fig. 6 and Fig. 7, the superiority of the present invention will be demonstrated with specific data below. Taking the external dimension of the internal circulation heat exchanger 12 as an example, the section in Fig. 6 is 25mm*60mm , assuming that the maximum area of the flow section of each water channel 123 is 1mm (usually 0.8mm-1.2mm)*25mm, the total area of the six water channels 123 is 6mm*25mm, and then the cross-sections of the plurality of fins 124 can be obtained The occupied area is (60-6)mm*25mm, and the section area occupied by any fin 124 is 10.8mm*25mm. When the hot air in the inner circulation air duct 311 passes through the several fins 124, the fins The distance from any point a on the chip to point b on the water channel 123 must be ≤ 5.4mm, which greatly shortens the physical distance of heat transfer. After the heat is transferred to the water channel 123 , it is taken away by the liquid inside the water channel 123 , and finally diffuses into the atmosphere through the water tank 14 . Compared with the physical distances of a'-b' and a"-b" in Fig. 8-Fig. 9, the ab distance in the present invention is much shorter. At the same time, it can be calculated according to experience that the heat exchange area of the internal circulation heat exchanger 12 on the internal circulation air duct 311 can easily exceed 2000m ² /mm ³ . This is totally impossible for the prior art shown in Figures 8-11. After considering wind resistance, the heat exchange area per unit volume is usually ≤1000m ² /mm ³ .

The wavy structure on the surface of the fins 124 is conducive to breaking the boundary layer of the fluid. Compared with the straight rib structure in Figures 8-11, the laminar flow effect will be much better, thereby increasing the heat transfer rate between the fins 124 and the air in the inner circulation air duct 311. In fact, this is also fully sealed. The machine expects the core of fast heat dissipation.

It should be noted that, in this document, the terms "comprising", "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, It also includes other elements not expressly listed, or elements inherent in the process, method, article, or apparatus.

In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above examples is only used to help understand the method and core idea of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that due to the limitation of digital expression, there are objectively unlimited specific structures. For those of ordinary skill in the art, without departing from the principle of the present invention, Several improvements, modifications or changes can also be made, and the above-mentioned technical features can also be combined in an appropriate manner; these improvements, modifications, or combinations, or the idea and technical solution of the invention are directly applied to other occasions without improvement, All should be regarded as the protection scope of the present invention.

Claims (6)

1. An indirect liquid-cooled LCD projector sealed optical machine is characterized by comprising a cooling system, an optical system and an optical machine shell (3);

the cooling system comprises a water pump (11), an internal circulation heat exchanger (12), a light source heat absorber (13), a water tank (14) and a flowmeter (18) which are sequentially arranged in the flowing direction of liquid; the cooling system further comprises an external fan (15) and an internal circulation fan (16);

the water pump (11), the internal circulation heat exchanger (12), the light source heat absorber (13), the water tank (14) and the flowmeter (18) are respectively provided with a water inlet and a water outlet, and the water pump (11), the internal circulation heat exchanger (12), the light source heat absorber (13), the water tank (14) and the flowmeter (18) are connected in series to form a loop to form a closed circulation flow channel; the closed circulating flow channel is filled with cooling liquid; the outer fan (15) is over against the water tank (14) for blowing or sucking.

2. The indirect liquid-cooled LCD projector sealing optical machine according to claim 1, wherein the number of the water pump (11), the internal circulation heat exchanger (12), the water tank (14), the external fan (15) and the internal circulation fan (16) is one or more;

when the number of the water pump (11), the internal circulation heat exchanger (12) and the water tank (14) is multiple, the water pump, the internal circulation heat exchanger and the water tank are connected into the cooling system in series or in parallel.

3. The indirect liquid-cooled LCD projector sealing optical machine according to claim 1, wherein the optical system comprises an LED light source (21), a condenser (22), a collimating lens (23), an LCD light valve (24), a field lens (25), an imaging mirror (26) and a projection lens (27) arranged in sequence along the light traveling direction; the light source heat absorber (13) is attached to the back surface of the LED light source (21);

one end of the optical machine shell (3) is provided with a light source mounting port, and the other end of the optical machine shell is provided with a lens mounting port; the LED light source (21) and the projection lens (27) are respectively and correspondingly arranged at the light source mounting opening and the lens mounting opening;

the condenser (22), the collimating lens (23), the LCD light valve (24), the field lens (25), the imaging reflector (26), the internal circulation heat exchanger (12) and the internal circulation fan (16) are arranged in the optical-mechanical shell (3); the water pump (11), the light source heat absorber (13), the water tank (14), the flow meter (18) and the outer fan (15) are positioned outside the optical machine shell (3);

an inner circulating air duct (311) which is closed-loop and circulates is arranged inside the optical machine shell (3), and the LCD light valve (24), the inner circulating heat exchanger (12) and the inner circulating fan (16) are arranged in the inner circulating air duct (311); the water inlet and the water outlet of the internal circulation heat exchanger (12) penetrate out of the optical machine shell (3).

4. The indirect liquid-cooled LCD projector sealing optical machine according to claim 1, wherein the internal circulation heat exchanger (12) comprises a first manifold (121), a second manifold (122), a plurality of water channels (123), a plurality of fins (124); each water channel is flat, and the outer surface of the flow cross section is rectangular or oval;

the surface of the fin (124) is in a wave-shaped structure;

when the number of the water channels (123) is less than that of the fins (124), two adjacent fins (124) are separated by one water channel (123), and two opposite outer planes of any one water channel (123) are respectively connected with the wave crest or the wave trough of the wave-shaped structure of one fin (124);

when the number of the water channels (123) is more than that of the fins (124), the wave crest or the wave trough of the wave-shaped structure of one fin (124) is connected between two adjacent water channels (123);

a blocking wall (1210) is arranged inside the first collecting pipe (121), and the first collecting pipe (121) is divided into two cavities which are not communicated through the blocking wall (1210); the two cavities which are not communicated are an inlet cavity (1211) and an outlet cavity (1212); the water inlet of the internal circulation heat exchanger (12) is communicated with the water inlet cavity (1211), and the water outlet of the internal circulation heat exchanger (12) is communicated with the water outlet cavity (1212);

one end of a part of water channels (123) in the water channels (123) is communicated with the water inlet cavity (1211) of the first collecting pipe (121); one end of the rest water channel (123) in the plurality of water channels (123) is communicated with the water outlet cavity (1212) of the first collecting pipe (121); the other ends of the water channels (123) are communicated with the second collecting pipe (122);

the cooling liquid flows into the water inlet cavity (1211) of the first collecting pipe (121) through the water inlet of the internal circulation heat exchanger (12), is divided through the water inlet cavity (1211), flows to the second collecting pipe (122) through a part of water channels (123) in the plurality of water channels (123) to be converged, further flows back to the water outlet cavity (1212) of the first collecting pipe (121) through the rest water channels (123) in the plurality of water channels (123), and flows out through the water outlet of the internal circulation heat exchanger (12).

5. The internal circulation heat exchanger according to claim 4, wherein the internal circulation heat exchanger (12) further comprises a skeleton (125); the first collecting pipe (121), the second collecting pipe (122), the plurality of water channels (123) and the plurality of fins (124) are installed inside the framework (125) after being assembled.

6. The indirect liquid-cooled LCD projector sealing optical machine according to claim 1, wherein the water pump (11), the internal circulation heat exchanger (12), the light source heat absorber (13), the water tank (14) and the flow meter (18) are connected in series through water pipes, and the water pipes are environment-friendly silicone tubes.

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