How does a U shaped tubular heat exchanger work?

Each tube of the U-shaped tubular heat exchanger is bent into a U-shape, the fluid inlet and outlet are installed on both sides of the same end, and the head is divided into two chambers with a partition, and each tube can be freely retracted to solve the problem of thermal compensation. The structure is simple, there is only one tube sheet, the sealing surface is less, the operation is reliable, and the cost is low; The tube bundle can be withdrawn, and the cleaning between the pipes (shell stroke) is convenient. Light weight, suitable for high temperature and high pressure occasions.

The pipe process is difficult to clean, and the pipe fluid must be a clean and non-scaling material, because the pipe needs a certain bending radius.

Therefore, the utilization rate of tubular sheet is low; The spacing of the innermost layer of the tube bundle is large, and the shell is easy to short circuit; The inner pipe cannot be replaced, so the holding rate is high. U-shaped tubular heat exchanger is suitable for occasions where the temperature difference of the tube and shell wall is large or the shell medium is easy to scale, and the pipe medium is clean and not easy to scale, and the high temperature, high pressure and strong corrosiveness are occasions. Generally, high temperature, high pressure, and corrosive medium are in the pipe, but the high-pressure space is reduced, the sealing is easy to solve, and the material can be saved and the heat loss can be reduced.

U-shaped tubular heat exchanger, a single heat exchanger has two tube plates.

Half of this heat exchanger has a parallel flow direction for the medium inside and outside the tube bundle, and the flow direction of the medium inside and outside the tube for the other half is counterflow. The twin tube sheets of the U-shaped tubular heat exchanger are generally connected to each other by polyliquid shells. The polyliquid shell can be used to adjust the spacing of the tubesheets and ensure that the two tubesheets are parallel to each other.

At the same time, the polyliquid shell is used to seal the gas (liquid) leakage between the adjacent two tube sheets to prevent the overflow of toxic gas (liquid). The highest and lowest parts of the polyliquid shell need to be set up with venting ports and clean ports respectively for timely export of leaking gas (liquid). If the temperature difference between the shell and the tube is large, in order to reduce the stress at the junction between the shell and the tube, the wall thickness of the short joint should be reduced as much as possible, and an expansion joint can be added if necessary.

The U-shaped tubular heat exchanger is composed of a tube box, a shell, a tube bundle, etc. The U-shaped tubular heat exchanger has only one tube sheet, no floating head, and all the structures are relatively simple. The heat exchange tube is made into a U-shape, and both ends are fixed on the same tube sheet, because the shell and the tube are separated, the thermal expansion can be ignored, and the tube bundle can be freely expanded and contracted, and the temperature difference stress will not be generated due to the temperature difference of the fluid medium.

Since the heat exchange tubes are all made into U-shaped bends with different radii, except for the outermost layer that can be replaced after damage, the rest of the tubes are only damaged by plugging the tubes. Compared with the fixed tube-plate heat exchanger, there is a gap in the central part of the tube bundle, and the fluid is easy to short-circuit, which affects the heat transfer effect, and the tubes arranged on the tubesheet are less than the fixed tube-plate heat exchanger, and the volume is somewhat large. In order to increase the flow rate of the fluid medium in the shell, baffles and longitudinal partitions can be arranged in the shell to improve the heat transfer effect.

U-shaped tubular heat exchanger is a kind of shell-and-tube heat exchanger, which is composed of tube sheets, shells, tube bundles and other parts. In the case of the same diameter, the heat exchange area of the U-tube heat exchanger is the largest; It has simple structure, compact, high sealing performance, easy maintenance and cleaning, minimum metal consumption and lowest cost under high temperature and high pressure; The U-shaped tube heat exchanger has only one tube sheet, which has good thermal compensation performance and strong pressure-bearing capacity, and is suitable for operation under high temperature and high pressure conditions. The main structure of U-shaped tubular heat exchanger includes tube box, cylinder, head, heat exchange tube, pipe, baffle, anti-impact plate and deflector tube, anti-short circuit structure, support and other accessories of tube shell process, etc.

It belongs to a kind of tube heat exchanger, the working principle of the heat exchanger is to transfer heat from the high temperature end to the low temperature section, each tube of the U-shaped tubular heat exchanger pipe is bent into a U-shape, the two ends of the tube are installed on both sides of the same fixed tube sheet respectively, and the head is separated into two chambers with a partition, each tube can be automatically contracted, and has nothing to do with other tubes and shells, even if the temperature difference between the shell and the tube is very large, the U-shaped tubular heat exchanger is commonly used for circulating water cooling high-temperature gas in actual production, After the heat exchanger tube is corroded or leaked, only the core can be replaced, but it should not be cleaned.

This is very simple, that is, the two working fluids exchange heat through the metal pipe wall, generally convection heat exchange.

Tubular heat exchanger is also known as shell and tube heat exchanger and tubular heat exchanger, and the working principle of tubular heat exchanger is as follows:

Shell-and-tube heat exchangers are made up of multiple layers of materials with good thermal conductivity, and work similarly to water heaters.

The water heater is generated by gas when burning, and the heat exchanger is a heating medium, not an open flame, there are two pipe circuits inside the heat exchanger, one is the heat source and the other is the heated source, the heat source is like the flame when the water heater burns, such as hot water or steam.

The source being heated is like the water being heated in a water heater. There is also a regulating valve in front of the heat source inlet of the heat exchanger in the heat source circuit, and the temperature of the heated source can be adjusted by changing the opening of this valve.

The working principle of Nianchun of tubular heat exchanger is as follows:

1. The heat exchanger with flat plate and fin Heng Gaoxian as heat transfer elements is mainly composed of plate bundle and head, etc., and there are several channels in the plate bundle.

2. Place fins between the two plates of each layer channel, and seal them with seals on both sides, and according to the different fluid flow methods, the cold and hot fluid channels are stacked at intervals, arranged and brazed into a whole, that is, made into a plate bundle.

3. The flow modes of the two fluids are countercurrent, cross-flow and cross-current, etc., the A and B fluids are respectively introduced into their respective plate bundle channels by the inlet head through the deflector of a distribution section, and then led to the outlet head by the deflector of another distribution section, the two fluids are counter-current wall heat exchange, and the commonly used fins are straight, porous, sawtooth and corrugated and other forms.

4. The main advantage of the clapper fin heat exchanger is compactness, because most of the heat is transmitted through the fins through the flat plate, and the heat transfer area per unit volume of the equipment can reach 1500 meters.

5. Sturdy, because the plate bundle is a whole piece and the fin plays a supporting role between the two plates, it can withstand high working pressure.

In heating engineering equipment, tubular heat exchanger is a kind of high-efficiency and energy-saving equipment. Due to its strong structure, large elasticity and strong adaptability, a lot of improvements have been made to the structure, process and materials in recent years, so that its technical performance tends to be more reasonable and advanced. The use in heating facilities is particularly critical, and now it is becoming more and more widely used in our lives, so among the many types of heat exchangers, tubular heat exchangers still occupy an important position.

Heat exchanger. Tubular heat exchanger What is a tubular heat exchanger Tubular heat exchanger is a very key device in the equipment, in daily life, we are more familiar with the tubular heat exchanger is to do shell and tube heat exchanger, in fact, it is a kind of wall heat exchanger, at present, in the process of heating transportation, tubular heat exchanger still occupies a leading position in various heat exchangers. The tubular heat exchanger that we can see is absolutely like a posture device, which is composed of four parts: shell, tube bundle, tube sheet and head.

Types of tubular heat exchangersWhat are the types of tubular heat exchangers? The common type is the fixed tube-plate type, through the welding of the tube and the shell, the tubular heat exchanger is very strong in fixity, and also ensures that the installation process of the tubular heat exchanger is relatively simple when it is installed.

Heat exchanger. However, the shell of the tubular heat exchanger is difficult to clean, and it is difficult to turn over because of its weight. In addition, there is a kind of floating head heat exchanger, the tube box of this tube heat exchanger is relatively large, and the shell is more flexible, easy to move, is a tube heat exchanger that can be moved at will.

U" type tubular heat exchanger, the shape of the heat exchanger on the "U" type, and the shell of the tubular heat exchanger and the heat exchanger are selected separately in the design, such a design ensures that the tubular heat exchanger can be freely expanded, and the simple structure is the representative of this tubular heat exchanger, so it is more convenient to clean the tubular heat exchanger. Moreover, the heat transfer effect of this tubular heat exchanger is still good, although it is not as good as the above two tubular heat exchangers.

Heat exchanger.

Answer]: a, d

See textbook p201).

Analysis] This question examines the production and installation of static equipment and process metal structures. The tung finger structure of the U-shaped tube heat exchanger is relatively simple, and the weight of the heavy shed is light, which is suitable for high temperature and high pressure occasions. The main disadvantage is that it is difficult to clean the tube and the dry inside, so the fluid in the tube must be clean; And because the pipe needs a certain bending radius, the utilization rate of the tube sheet is poor.

A heat exchanger with a flat plate and fins as heat transfer elements. It is mainly composed of plate bundles and heads, etc. There are several channels in the plate bundle.

Fin is placed between the two plates of each layer of passage and sealed with seals on both sides. Depending on the fluid flow mode, the cold and hot fluid channels are stacked at intervals, arranged and brazed into a whole, that is, a plate bundle is formed. The two fluid flow modes include reverse flow, cross flow and wrong reverse flow.

A and B fluids are respectively led by the inlet head through the deflector of a distribution section into their respective plate bundle channels, and then through the deflector of another distribution section to the outlet head and lead out, the two fluids are counter-current wall heat exchange.

Tubular heat exchanger is the most typical partition heat exchanger, mainly composed of shell, tube bundle, tube sheet and head, etc., the shell is mostly round, and the inside is equipped with parallel tube bundles, and the two ends of the tube bundle are fixed on the tube sheet.

Tubular heat exchanger is the most widely used heat exchanger in chemical and alcohol production. It is mainly composed of shell, tube sheet, heat exchange tube, head, baffle baffle, etc. The required materials can be made of ordinary carbon steel, copper, or stainless steel.

During heat exchange, a kind of fluid enters from the connecting pipe of the head, flows in the tube, and flows out from the outlet pipe at the other end of the head, which is called the pipe process; Another type of fluid enters through the tube of the shell and flows out from another tube on the shell, which is called the shell pass.

The heat exchanger tube of the U-shaped tube heat exchanger is U-shaped, the two ends are fixed on the same tube sheet, the tube bundle can be freely expanded, and the temperature difference stress will not be generated due to the temperature difference of the medium, because this heat exchanger has only one tube plate, and there is no floating head, so it is cheaper than the floating head type, the structure is also simple, and the tube bundle can be extracted to clean the tube, which is the advantage of this heat exchanger. (Force and Hyde heat exchangers).

The disadvantage is that the heat transfer performance is poor due to the large spacing between the tubes, especially the gap in the middle part. Due to the different curvatures of each row of pipes and the different lengths of the pipes, the distribution of pipes is not as uniform as that of straight pipes. The pipe in the middle of the bundle can not be checked and replaced, and the scrap rate of the pipe after plugging is twice as large as that of the straight pipe, because a tube sheet bears all the supporting effects, and the thickness of the tube sheet with the same inner diameter of the shell is greater than that of other forms.

When the diameter of the heat exchanger is large, the U-shaped part is difficult to support, and the vibration resistance of the tube bundle is poor.

Our company undertakes the installation, upgrading and transformation of heating machine room, plate heat exchanger maintenance and cleaning and other related businesses, and the company's employees have more than 10 years of industry experience and have served the world's top 500 enterprises for many years. Customers are located in Beijing, Tianjin, Hebei, Northeast, Northwest and other regions, specializing in providing heat exchange solutions for various working conditions.