What kind of heat exchanger does a positive displacement heat exchanger belong to?

Volumetric heat exchangers belong to shell and tube heat exchangers, partition heat exchangers, and special heat exchangers for domestic hot water. What does that mean? This equipment is only used for the preparation of centralized domestic hot water, such as bathing water for hotels, hospitals, schools, etc.**, and is not suitable for the preparation of hot water in individual homes and residential quarters.

In terms of composition: the positive displacement heat exchanger is mainly composed of a water tank and an internal heat exchange tube bundle. Cold water flows in the tank, and high-temperature hot water or steam flows in the heat exchange tube.

The two kinds of water are not in direct contact, and the heat is transferred through the wall of the heat exchange tube, and the cold water is heated to 50-60 degrees Celsius, which is output from the top of the tank, and follows the pipe, ** to every water room and outlet point of the hotel.

From this, you can understand what is the meaning of wall heat exchanger and shell and tube heat exchanger.

Volumetric heat exchanger: wall heat exchanger can be divided into tube, plate and other types according to the structure of the heat transfer surface. Tubular heat exchangers use the surface of the tube as the heat transfer surface, including snake tube heat exchanger, casing heat exchanger and shell and tube heat exchanger. Plate heat exchangers use plate surface as the heat transfer surface, including plate heat exchanger, spiral plate heat exchanger, plate-fin heat exchanger, plate and shell heat exchanger and umbrella plate heat exchanger, etc.; Other types of heat exchangers are heat exchangers designed to meet certain special requirements, such as scraped surface heat exchangers, rotary plate heat exchangers and air coolers.

<> Vertical model drawings of positive displacement heat exchangers.

1. RV series

Its full name is the diversion type volumetric heat exchanger, divided into RV-04 vertical and RV-03 horizontal two, to the model as an example, introduction: the volume is cubic meters, indicating the design pressure of the pipe, indicating the design pressure of the shell. 04 represents a vertical structure, and 03 represents a horizontal structure.

2. HRV series

Its full name is diversion type semi-volumetric heat exchanger, in the model designation, HRV-02 refers to vertical structure, HRV-01 refers to horizontal structure. Taking the model as an example, it is the volume, which represents the design pressure of the pipe and the design pressure of the shell.

Models of horizontal positive displacement heat exchangers.

3. DFHRV series

Its full name is diversion floating coil semi-volumetric heat exchanger, it only has a vertical structure, taking the model as an example, 1600 represents the diameter of the equipment, is the volume size, h means that the heat source is high temperature water, indicates the design pressure of the pipe, and indicates the design pressure of the shell.

4. THF series

Its full name is floating coil semi-volumetric heat exchanger, there are THF-W horizontal structure and THF-L vertical structure, for example, model, 1200 indicates its diameter size, L represents vertical, A represents a single tube bundle, Q indicates that the heat source is steam, is the volume size, 8 indicates the heat exchange area.

"(1) According to the different types of heat exchange tubes, it is divided into: diversion type volumetric heat exchanger (common model is RV series, such as "RV-04-5 (or" RV-03-8S (floating coil volumetric heat exchanger (common model is CFP series, for example, "diversion type semi-volumetric heat exchanger (often see the model.

Volumetric heat exchanger is mainly composed of vessel body, steam coil assembly, steam inlet and outlet, hot and cold water inlet and outlet etc., in order to prevent corrosion on the surface of the body of the vessel, a layer of anti-corrosion alloy layer is sprayed on the surface, and a paint layer is brushed on the alloy layer, and the original pipe box is canceled, and the steam coil is directly connected through the flange, so that the utility model has the characteristics of simple and reasonable structure, long service life, good heat exchange effect, energy saving and so on. Advantages of positive displacement heat exchanger: The temperature drop of the heat medium of the positive displacement heat exchanger is large.

When the heat exchange of steam and water, the temperature of the condensate outlet is about 50, and the water trap needs to be set up above and below the return pipe, which brings convenience to the use and maintenance, and when the water-water heat exchange, the heat temperature drops to 2 times that of the same type of heat exchanger, and the high temperature hot water of 120 150 can be reduced to 70 75 after heat exchange. The positive displacement heat exchanger has good heat exchange effect, good heat dissipation effect, small heat dissipation loss and energy saving. At the same time, when steam is used as the heat medium, it can account for about 15% of the condensate heat of the entire heat exchange.

The cold water area is small and the volume utilization rate is high. It maintains the advantages of large water storage, low head loss, safe and stable water supply, and convenient scale removal of the volumetric heat exchanger. Positive displacement heat exchanger selection method:

The selection is completed through calculation, the heat exchange area is calculated to complete the selection, and the use in production is simple, and the specifications and models can also be selected according to experience, and most of them need to be selected after detailed calculations. The selection of volumetric heat exchanger should first consider the hourly water consumption, and then consider the buffer volume to prevent the hot water from being cold and hot, and the general buffer volume is 1 4. Or follow the buffer water for 10 to 15 minutes.

The positive displacement heat exchanger is composed of three main parts: hot water storage tank, built-in heater and automatic temperature control, and the main structural features are: the U-shaped tube with good heat transfer effect of multi-return program is used as the heating element, and the inspection hole is opened on the side to facilitate maintenance, and the water supply is designed according to the flow rate of seconds, and the water supply can be maintained smoothly even at the peak of water consumption. It is easy to realize automatic temperature control, and the water supply pressure changes very little, so as to ensure the balance of cold and hot water pressure in the system.

The heating part has high heat transfer coefficient, large heat exchange, sufficient heat exchange, and is convenient for maintenance. The heat exchange structure is mainly U-shaped tube, and the net spacing of the outer wall of the pipe is 11 25mm, which is convenient for scale cleaning and maintenance.

Glad to answer this question for everyone, the positive displacement heat exchanger is in the hotel. It is often used in hospitals, schools and other HVAC projects, and the following will introduce its structure, principle and use.

Uses:

Positive displacement heat exchanger is a tank type equipment for heat exchange between two cold and hot mediums, the cold medium is generally water, and the hot medium is generally steam, high temperature water, solar high temperature solution, air source high temperature water, etc., the cold water is heated to 55 or 60 degrees Celsius, and then the pipeline is transported to the water room for hot water purposes such as bathing or hand washing.

Structure

The internal structure of the positive displacement heat exchanger is mainly composed of a tank and a heat exchange tube bundle, the tank is generally made of carbon steel or stainless steel, and the tube bundle is generally stainless steel and copper tube bundle. In addition, the internal structure of the heat exchange tube bundle is slightly different depending on the coil or U-tube.

How it works

Through the above description, you should basically know that after the cold water is pressurized by the water pump, it enters the tank, and the high-temperature energy of the heat source in the tank is heat exchanged to the cold water of the tank through the tube bundle, so that it can be heated to meet the temperature and water production requirements of the use, and then output from the top outlet pipe, enter the hot water pipeline to the hot water point, if the water temperature is not used or cooled, the water will be returned to the tank and heated again.

Equipment features:

1) It has the functions of heat exchange and heat storage. The upper part of the heat exchange tube bundle of the positive displacement heat exchanger is the heat storage part, which belongs to the same temperature hot water area, with large heat storage and can adapt to the change of hourly heat consumption; It can provide a large storage and adjustment volume for hot water systems** with uneven water use to adapt to changes in water load; The outlet temperature is stable, and the water supply is safe and reliable.

2) The resistance loss of the heated water through the tank is very small. Because the cold water passes through the volumetric heat exchanger, the water section is very large, the flow rate is not enough, and the resistance loss is very small, which is generally only, which is extremely beneficial to maintain the balance of the pressure of the cold and hot water supply at the water point.

3) The requirements for heat medium are not strict. The volumetric heat exchanger has a large heat storage volume, and its heating load can be calculated according to the maximum hourly heat consumption, which can halve the load of the boiler and pipe network, greatly saving the investment in the heat medium supply system, and the use of hot coal is relatively uniform, which is conducive to improving the thermal efficiency of the boiler and prolonging its service life.

4) Simple structure, convenient management, can withstand water pressure, low noise.

Hope the above positive displacement heat exchanger technology can help everyone, thank you!

Hello everyone, I often see that everyone has doubts about volumetric and semi-volumetric heat exchangers, what is the difference between these two types of hot water equipment? Below, this time for everyone's technology is as follows, I hope to help you with Antie Wu. (Original technical answer, know the release, please do not **).

Structural drawings of semi-positive displacement heat exchangers.

1. The difference in selection

Both kinds of equipment will be used in the demand for domestic hot water in building places, such as hospitals, hotels, solar water heating projects, etc., both types can be selected according to the relevant atlas "CJT163-2015 Diversion Volumetric Water Heater and Semi-Volumetric Water Heater", from the name and selection data table, it can be seen that they belong to two different equipment.

2. It is different in terms of structure

You can check its appearance, positive displacement and semi-positive displacement heat exchangers belong to one side plug or into the heat exchange U-shaped tube bundle, but the position of the heated water inlet is different, the RV series water inlet is at the bottom of the tank, and the HRV series is on the side of the tube box, and the HRV series may be designed with manholes, while the RV series often does not. Placed in others, the shape and structure are basically the same.

3. Differences in performance

Comparing the selection data of these two heat exchangers, we will find that when the same volume size, the heat exchange area of the semi-volumetric heat exchanger is often larger, especially the design of the water inlet on the side of the tube box, which can make the water be heated faster. However, there is a small disadvantage that the effluent temperature may fluctuate greatly.

There are many domestic enterprises engaged in the manufacture of volumetric heat exchangers, mainly distributed in Shandong, Beijing, Shanxi, Jiangsu, Sichuan, and Guangdong. When choosing a brand, there are a few suggestions to share with you.

1. Whether it has a pressure vessel manufacturing license, which is a national certification standard for comprehensively judging its welding level.

2. Whether to manufacture volumetric heat exchangers in batches, if a factory is very professional in manufacturing, but a total of several volumetric heat exchangers are produced a year, it is not reliable in quality. The maturity of the technology is obtained by the processing experience of hundreds of units.

When choosing a positive displacement heat exchanger brand, we should focus on the above two points, and I believe that there will be satisfactory results.

I hope the above objective answers can help everyone, thank you!

Hello, in view of the working principle of the volumetric limb heat exchanger that everyone is more concerned about, I will share the following relevant knowledge for you, and I hope you are satisfied. (Original technical answer, please do not**).

1. Working principle

By using the heat exchange principle of heat conduction, the saturated steam (or high-temperature water) of the primary heat source is exchanged with the cold water on the secondary side through the heat exchange tube (stainless steel or copper), and the heat source energy is transferred to the water, so that the water temperature rises, so as to achieve the purpose of the heat exchanger.

Schematic diagram of the working principle of a positive displacement heat exchanger.

2. Operating principle

The primary saturated steam (or high temperature water) transfers heat to the secondary water through the main volumetric heat exchanger coil, so that the temperature of the secondary water rises to 60, and an electric control valve is installed at the inlet of the positive displacement heat exchanger steam (or high temperature water) to adjust the flow of the heat source to ensure that the outlet temperature of the secondary water reaches the set working temperature. A safety valve is installed at the secondary water inlet to ensure that the equipment operates under safe working conditions, and the electric control valve adjusts the flow through the signal sent by the temperature of the secondary water outlet to achieve the purpose of automatic control.

3. Structural principle

The volumetric heat exchanger is composed of heat exchange Lizhou tube, volumetric tank, various inlets and outlets, instrument ports, tube boxes or main and auxiliary pipe bundles and other components. In terms of material, it is mainly composed of carbon steel lined stainless steel and all stainless steel. The structure is simple, and the welding manufacturing is relatively mature.

Volumetric heat exchanger is a heat exchanger that uses cold and hot fluids to flow alternately through the surface of the heat storage body (packing) in the regenerator chamber to exchange the residual amount of the hot ridge, and the cold and hot fluids of the partition wall volumetric heat exchanger are separated by the solid partition wall and carry out heat exchange through the partition wall, so it is also called surface heat exchanger. A kind of volumetric heat exchanger, it is mainly made up of vessel body, steam coil assembly, steam inlet and outlet, hot and cold water inlet and outlet etc., in order to prevent the surface corrosion of the body of the vessel, a layer of anti-corrosion alloy layer is sprayed on the surface, and the oil cherry blossom paint layer is brushed on the alloy layer, and the original pipe box is canceled in addition, and the steam coil is directly connected by the flange, and the utility model has the characteristics of simple and reasonable structure, long service life, good heat exchange effect, energy saving and so on.

Hello, positive displacement heat exchanger can be divided into many types according to the different types of structure, material and heat source. (Original technical answer, please do not**).

1. According to the structure

According to the structure of the heat exchange tube bundle, it can be divided into coil volumetric heat exchanger (CFP or THF series), U-tube volumetric heat exchanger (RV or HRV series), and according to different bearings, it can be divided into vertical volumetric heat exchanger and horizontal volumetric heat exchanger.

Positive displacement heat exchanger for copper coils.

Positive displacement heat exchanger with copper U-tube.

2. According to the material

The better material is the all-stainless steel volumetric heat exchanger, the slightly inferior is the carbon steel lined stainless steel, the heat exchange tube stainless steel, and the more general shell carbon steel, the heat exchange tube stainless steel. In addition to stainless steel, the heat exchanger tube can also be made of copper T2.

3. Follow the heat source

Common heat sources are mainly saturated steam, high-temperature water, high-temperature aqueous solution three kinds, among which the use of saturated steam volumetric heat exchanger is called the supervision and inspection of pressure vessel equipment, the state stipulates that the need for a local special equipment manufacturing license can be produced, sold, installed, and need to be filed with the Quality Supervision Bureau. The volumetric heat exchanger using high-temperature water (aqueous solution) is an ordinary pressure vessel and can be manufactured by a general manufacturing plant.

I hope the above introduction to the types of positive displacement heat exchangers can help you, thank you.