The typical greenhouse finned tube is composed of tube, wick and bearing end cover（ After the air pressure of 10 - 1 - (10 - 4) Pa is filled with appropriate working liquid, the porous structure of the suction core close to the inner cavity of the pipe is filled with liquid, and the sealing performance is various. One end of the tube is the evaporation section (heating section) and the other end is the cooling section (refrigeration section). According to the application, the heat insulation section must be arranged in the middle of each section. When one end of the greenhouse finned tube is heated, the liquid in the wick vaporizes, and the steam flows into the other end under a slight pressure difference to release heat and solidify into liquid, and then the liquid flows to the volatilization section along the porous structure under the action of pore like force. In this circulation system, the heat is transferred from one end of the finned tube to the other; End. During the whole process of heat transfer of greenhouse finned tubes, the following six key processes are involved
(1) The calorific value is transferred from the heat source to the (liquid vapor) sub page according to the wall thickness of the greenhouse finned tube and the wick filled with working liquid;
(2) The liquid volatilizes on the (liquid vapor) interface surface in the volatilization section;
(3) The vapor in the vapor chamber flows from the evaporation section to the cooling section;
(4) The surface solidification of vapor at the interface of vapor and liquid in the cooling zone
(5) The calorific value is sent from the (vapor-liquid) separation surface to the storage tank according to the wick, liquid and wall thickness
(6) In the wick, the capillary action makes the liquid flow back to the volatilization section.
Basic features
Greenhouse finned tube is a kind of heat conduction component which completes heat conduction by means of liquid change in its internal work. It has the following basic characteristics.
1. Very high heat transfer
Greenhouse
Finned tube The internal key depends on the vapor and high efficiency liquid phase change heat conduction of the working liquid, and the heat transfer coefficient is not large, so it has high heat transfer ability. Compared with silver, copper, aluminum and other metal materials, the net weight of greenhouse finned tube can transmit many orders of magnitude more heat. Naturally, high heat transfer performance is also relative. The temperature difference always exists, which is unlikely to violate the second basic law of heat. Moreover, the heat transfer capacity of greenhouse finned tubes is limited by many factors, and there are some heat transfer limits; The radial heat transfer performance of the greenhouse finned tube is very strong, and the axial heat transfer performance is not greatly improved (except for the axial greenhouse finned tube).
2. High quality isotherm
The vapor in the inner wall of the greenhouse finned tube is saturated, and the working pressure of the saturated water vapor is determined by the saturation temperature. The pressure drop caused by the saturated water vapor flowing from the volatilization section to the cooling section is not large. According to the chemical equation in the thermodynamics, the temperature drop is not large. Therefore, the greenhouse finned tube has excellent isotherm.
3、Heat flux plasticity
The total heating area of evaporation section or refrigeration section can be changed by the greenhouse finned tube, that is, the calorific value can be input by a small heating area and output by a large refrigeration area, or the calorific value can be input by a large heat conduction area and output by a small refrigeration area, that is, the heat flux can be changed, Deal with some heat conduction difficulties that can not be solved by other methods.
4、The intersection of thermal gas orientation
Because the driving force of the internal circulation system of a horizontally placed finned tube in a greenhouse is a hole like force, one end of the tube can be regarded as the volatilizing section when it is heated, and the other end can be regarded as the cooling section when it is heated. This feature can be used for the temperature deployment of spaceships and artificial earth satellites in indoor space, as well as for chemical changers and other equipment that first exothermic reaction and then endothermic reaction.
5、Thermal diode and thermal power switch characteristics
The finned tube of greenhouse can be made into thermal diode or thermal power switch. In other words, the thermal diode only allows the hot gas to flow in one direction, but not in the other direction; When the temperature of the heat source is higher than a certain temperature, the greenhouse finned tube starts to work. When the temperature of the heat source is lower than this temperature, the greenhouse finned tube does not conduct heat.
6、Temperature control characteristics (controllable greenhouse finned tube)
In general, the heat transfer coefficient of each part of the finned tube in greenhouse does not change with the change of heating value. Therefore, when the heating value changes, the temperature of the spare part of the finned tube also changes. However, we have developed another kind of greenhouse finned tube —— The variable heat conduction tube makes the heat transfer coefficient of the cooling section decrease with the increase of the heating value, and increase with the decrease of the heating value. In this way, the steam temperature change of the greenhouse finned tube is very small when the heating value changes greatly, and the temperature control is completed. This is the temperature control characteristics of the greenhouse finned tube.
7、Adaptability to natural environment
The shape of the greenhouse finned tube can be changed according to the standards of pyrogen and cold storage. The greenhouse finned tube can be made into the transmission shaft of the motor, the leaf of the gas turbine, the twist drill, and the surgical treatment. The greenhouse finned tube can also be made into the component type, so as to integrate the heat transfer under the condition that the long-distance heat transfer or the heat shock hydrodynamics cannot be mixed; The finned tube of greenhouse can be used not only for road surface (gravity field), but also for indoor space (no gravity field). The greenhouse fin tube radiator is based on the high frequency welding technology plus the flake plate fin type, so the installation and application should avoid the impact extrusion molding, which will be very easy to deform, and even endanger the actual effect of heat removal.
Because the fin tube radiator in greenhouse is spiral, there will be some precipitation and rust layer in long-term application, so we should clean it immediately.
Check whether the connecting part is loose and the cushion falls off at the bracket of the radiator of the finned tube in the greenhouse.
The radiator of greenhouse fin tube is exposed to the outside area to prevent precipitation from sinking, keep dry and impetuous as possible, and the distance between the road surface is not suitable for too close, so as to prevent the irrigation in the vegetable shed from eroding the radiator of greenhouse fin pipe.
According to the maintenance of greenhouse finned tube radiator, the service life of greenhouse finned tube radiator has been greatly improved. All the long-term application of an object is indispensable, serious maintenance and maintenance, greenhouse finned tube radiator is not included, so actually from which aspect to maintain the greenhouse finned tube radiator? Let's take a look at the detailed introduction given by the authoritative experts of the greenhouse finned tube radiator network.
1、Regularly maintain the radiator of each greenhouse fin tube, whether there is accumulation, slag, rust layer and other fouling adhesion, and timely carry out cleaning. In addition, it is necessary to check whether the adhesive between the radiator of finned tube and rubber washer in each greenhouse is inseparable, whether the rubber washer is intact itself, so as to prevent leakage caused by rubber gasket opening and damage.
2、The screw cap and the left and right guide rods of flat plate heat exchanger should be lubricated frequently.
3、All instrument panel adjustment shall be undertaken by full-time personnel, and the actual operation and maintenance shall be carried out in strict accordance with the safety operation regulations.
4、When the rubber gasket needs to be removed or a part of the sealant needs to be repaired, it is necessary to remove the rubber gasket from the finned tube radiator of the greenhouse, put it on the table, remove the old sealing ring, or wipe off the strong adhesive of the concave groove of the finned tube radiator of the greenhouse with sandpaper at the sealant opening place, and then wipe off the oil stains in the concave groove with carbon or other organic solvents, Then rub the back of the new vulcanized rubber sealing ring with sandpaper, and dry it a little, so as not to stick to the fingers, but still sticky. Put the rubber gasket into the groove, smooth it all around, and apply a layer of calcium powder. Then install the greenhouse fin tube radiator into the machine equipment sound card frame and gently clamp it. According to the instructions for the use of super glue, it can be built and put into operation after a period of time.
5、When clamping the greenhouse fin tube radiator again, pay attention to the scale position of the last clamping. Do not press the rubber gasket too much, so as to reduce the service life of the sealing ring.
6、When removing and replacing the rubber gasket of the greenhouse fin tube radiator, it is necessary to upgrade all parts of this section, so as to prevent the uneven gap of each piece from endangering the actual effect of heat conduction.
