NB/T 47006-2019Aluminum plate-fin heat exchanger (English PDF)

1.1

This standard specifies the design, manufacture, inspection, acceptance, installation, use and maintenance requirements of aluminum plate-fin heat exchangers (hereinafter referred to as “heat exchangers”).

1.2

This standard is applicable to heat exchangers with design pressure not greater than 10.0MPa.

1.3

This standard is applicable to -269°C~200°C design temperature of heat exchangers.

1.4

This standard is applicable to heat exchangers used in air separation and liquefaction, natural gas processing and liquefaction, petrochemical engineering and mechanical power devices, etc.

1.5

The pressure elements of heat exchangers that cannot be designed and calculated by this standard can be designed according to the method specified in 4.1.6 of GB/T 150.1-2011.

1.6 Scope of heat exchangers

a) Heat exchanger body and its connection with external pipeline:

1) The groove end face of the first circumferential joint of welded connection;

2) The first flange sealing surface of flange connection;

3) The first threaded joint end face of threaded connection;

4) The first sealing surface connected with special connecting pieces or pipe fittings.

b) The connection welds between pressure elements and non-pressure elements.

c) Non-pressure elements directly connected to the heat exchangers, such as supports, lifting lugs, base plates, etc.

d) Overpressure relief devices directly installed on the heat exchangers.

3.1 plate-fin heat exchanger

the heat exchanger consisting of accessories such as core, header, nozzle and support Figure 1 shows a plate-fin heat exchanger (hereinafter referred to as a “heat exchanger”)

Figure 1 Plate-fin heat exchanger

3.2 core

the core consisting of various fluid channels which are banked and brazed into a whole according to the design requirements. Each layer of channel consists of parting sheet (cap sheet), heat transfer fin (distributor fin), side bar, etc., as shown in Figure 2

Figure 2 Single-layer channel structure

3.3 heat transfer fin

wavy element for heat transfer enhancement and pressure bearing between two parting sheets in the core

3.3.1 fin type

fin type indicating the geometric shape of the fin, mainly including plain fin, serrated fin, wavy fin, etc., among which plain fin and wavy fin can be perforated into perforated fin as required

3.3.2 percentage of opening

the ratio of the surface area of the heat transfer fin reduced after opening of the perforated fin to the total surface area of the heat transfer fin before opening

3.4 distributor fin

the fin that distributes the fluid into the core at the inlet and outlet, which is generally plain (perforated or non-perforated) fin

3.5 side bar

an element of the heat exchanger core for sealing and supporting each layer of channel

3.6 parting sheet

a sheet in the heat exchanger core that is used for separating the fluid between two layers of fins and is welded with the heat transfer fin and the side bar to form a whole during brazing

3.7 cap sheet

a cap sheet located at the outermost side of the heat exchanger core

3.8 dummy layer

the channel layer which is set at the top and bottom of the core to connect with the ambient atmosphere and doesn’t involve heat exchange. The dummy layer only meets the requirements of strength, thermal insulation and manufacturing process

3.9 dead area

the area in a channel that is connected with the heat transfer fin or distributor fin but has no medium flow

3.10 layer arrangement

a channel arrangement required to realize heat exchange between cold and hot media, including single banking, double banking, and single and multiple banking

3.10.1 single banking

an arrangement that each hot channel is arranged adjacent to a cold channel, as shown in Figure 3 a)

3.10.2 double banking

an arrangement that each hot channel is alternating with two alternating cold channels, or each cold channel is alternating with two hot channels, as shown in Figure 3 b)

3.10.3 single and multiple banking

the combination of single banking and double banking in the same core, besides hot channel is arranged adjacent to cold channel in the same core, as shown in Figure 3 c)

Figure 3 Channel arrangement diagram

3.11 header

a header that is usually welded of header body, nozzle, header with ends, flange (or nozzle cap), etc.

3.11.1 header body

the semi-cylindrical part of the header

3.11.2 header with ends

the plate connecting both ends of the semi-circular header and the header body

3.11.3 nozzle

the pipe connecting the external pipeline and the header

3.11.4 nozzle cap

a part that are used to close the nozzle during pressure test or nitrogen sealing

3.12 composite block

a core that two or more cores are connected into a whole by parallel welding, as shown in Figure 4

3.13 manifolded exchanger

a combination of two or more heat exchangers in different piping forms (in parallel or in series), as shown in Figure 5

3.14 heat transfer area

the sum of heat transfer surface areas of all channels of the same fluid, including areas of primary heat transfer surface and secondary heat transfer surface

3.14.1 primary heat transfer surface

a heat transfer surface provided by the parting sheet

3.14.2 secondary heat transfer surface

a heat transfer surface provided by the heat transfer fin, with the surface where the heat transfer fin is directly welded with the parting sheet removed

3.15 equivalent diameter

the diameter of circular pipe that is obtained by converting the dimension of non-circular channel according to the principle of equal hydraulic radius

Figure 4 Structure diagram of composite block

Figure 5 Composition diagram of manifolded exchanger

4.1 General

4.1.1

In addition to the requirements of this standard, the design, manufacture, inspection, acceptance, installation and use of heat exchangers shall also meet the requirements of the purchaser or the relevant laws, regulations and standards directed by the purchaser, as well as the drawing requirements.

4.1.2

See Annex A of GB/T 151-2014 for the declaration of conformity of this standard.

4.2 Pressure

4.2.1

The heat exchanger consists of several (equal or unequal) pressure channels. The respective design pressures shall be determined according to the dangerous working conditions that may occur during the operation of each channel.

4.2.2

The design pressure of each channel shall not be less than the maximum working pressure of the channel.

4.2.3

When the heat exchanger is designed according to external pressure, the maximum difference between internal pressure and external pressure that may occur during manufacture and use shall be considered.

4.2.4

When the heat exchanger works in vacuum, the design pressure of the vacuum channel shall be considered according to its external pressure. When a safety control device is provided, the design pressure shall be 1.25 times the maximum difference between internal pressure and external pressure or 0.1MPa, whichever is smaller; when no safety control device is provided, the design pressure shall be 0.1MPa.

4.2.5

The design pressure shall not be greater than the maximum allowable working pressure of the heat transfer fin determined by the burst test.