CN-122015533-A - Efficient tubular heat exchanger and operation control system thereof

CN122015533ACN 122015533 ACN122015533 ACN 122015533ACN-122015533-A

Abstract

The invention discloses a high-efficiency tubular heat exchanger and an operation control system thereof, which belong to the technical field of heat energy recovery of a papermaking drying process, and improve the temperature uniformity of fins along the circumferential axial direction and the height direction of a heat exchange tube body by the cooperative design of intermittent spiral fins and axial diversion heat bridges, continuously guide and comb air flow, efficiently destroy a heat boundary layer to overcome the defect of poor heat transfer of a traditional heat exchange tube, not only improve the heat transfer coefficient of an air side, but also remarkably improve the dust accumulation resistance.

Inventors

LV PEIZHI
CHEN ZHENLIANG
Ren Beihui
LIANG FENG
PANG ZIJIE
LIU YAOJING
XIE YINGYING

Assignees

维达护理用品(广东)有限公司

Dates

Publication Date: 20260512
Application Date: 20260227

Claims (8)

1. The efficient tubular heat exchanger comprises a tubular heat exchange structure connected with a flash tank (1) through a pipeline and is characterized by comprising an S-shaped flow pipe (2) arranged in a heat exchange tube shell, wherein an S-shaped heat exchange tube (3) is sleeved in the S-shaped flow pipe (2), a heat exchange space is formed between the S-shaped flow pipe (2) and the S-shaped heat exchange tube (3), the S-shaped heat exchange tube (3) comprises a plurality of straight pipe fin sections (31) which are arranged in parallel and bent pipe straight sections (32) arranged at two ends of the straight pipe fin sections (31), a pair of bent pipe straight sections (32) positioned at two ends are respectively externally connected with a heat medium inlet pipe (33) and a heat medium outlet pipe (34) which extend to the outside of the S-shaped flow pipe (2), two ends of the S-shaped flow pipe (2) are respectively provided with an exhaust pipe (5) and an exhaust pipe (6), and the exhaust pipe (6) are externally connected with a drying gas hood; The outer wall of the straight tube fin segment (31) is distributed with a plurality of axial flow guide parts (7) which are parallel to the axial direction of the straight tube fin segment and are communicated with the inside of the straight tube fin segment, and the heat exchange space is provided with spiral fins (4) which are embedded with the straight tube fin segment (31) and the axial flow guide parts (7).
2. A high efficiency tubular heat exchanger according to claim 1 wherein the axial flow guide portion (7) is axially parallel to and axially protrudes from the straight tube fin segment (31), and the axial flow guide portion (7) has a triangular-like structure in a plane-like cross section in arc-shape with the outer tube wall of the straight tube fin segment (31), and comprises an arc-shaped cross section, a long inclined plane and a short inclined plane.
3. A high-efficiency tubular heat exchanger according to claim 2, wherein the extending direction of the long inclined plane of the axial flow guiding part (7) is adapted to the spiral direction of the air flow guided by the spiral fin (4), the short inclined plane is smoothly transited to the wall of the straight fin segment (31), the spiral fin (4) is provided with a clamping groove or a connecting surface matched with the shape of the axial flow guiding part (7), and the spiral fin is fixed on the axial flow guiding part (7) in an embedding, welding or brazing mode.
4. An operation control system of a high-efficiency tubular heat exchanger, which is applied to the high-efficiency tubular heat exchanger as claimed in claim 3, and is characterized by comprising an operation control platform, a heat source supply and pressure stabilizing module and a hot air actual temperature regulating module; the operation control platform is used as a data processing and command center of the system, and is embedded with: The vehicle speed-steam demand database is established by simulating different vehicle speeds and corresponding steam demand working conditions under the gram weight of raw paper and is used for mapping real-time vehicle speeds to total steam demand loads; a paper type-temperature database which is grouped according to paper types and gram weights and stores corresponding hot air actual temperature reference setting values; the temperature and humidity compensation algorithm model is used for calculating the compensation quantity of the temperature reference set value according to the real-time environment temperature and humidity; a flash tank pressure set point; The heat source supply and voltage stabilizing module is used for receiving a real-time vehicle speed signal from the paper machine, inquiring the vehicle speed-steam demand database to obtain a predicted total steam demand load, generating a feedforward opening command for the flash tank outlet regulating valve according to the predicted total steam demand load, collecting the flash tank outlet manifold pressure in real time, comparing the pressure with a flash tank pressure set value, generating a feedback regulating command through a PID (proportion integration differentiation) control algorithm, superposing the feedforward opening command and the feedback regulating command, and commonly controlling the opening of the flash tank outlet regulating valve; The hot air actual temperature regulation and control module is used for collecting the hot air actual temperature and the ambient temperature and humidity of an outlet of the exhaust pipe (6) or a downstream drying gas hood in real time, inquiring a paper type-temperature database to obtain a hot air actual temperature reference set value according to the paper type and gram weight of the current production, inputting the ambient temperature and humidity into the temperature and humidity compensation algorithm model to obtain compensation quantity, correcting the reference set value to obtain a target temperature, comparing the target temperature with the hot air actual temperature, and dynamically regulating the opening of a regulating valve on the exhaust pipe (6) through a PID control algorithm.
5. The operation control system of the high-efficiency tubular heat exchanger according to claim 4, wherein the hot air actual temperature regulation module further executes control logic for continuously acquiring the hot air actual temperature and the target temperature under the same time stamp, respectively establishing a hot air actual temperature trend curve and a target temperature trend curve in the same coordinate system by taking time as an x axis and taking temperature as a y axis, calculating a temperature comprehensive deviation value in a certain time window according to the hot air actual temperature trend curve and the target temperature trend curve, comparing the temperature comprehensive deviation value with a preset allowable deviation range, generating a pressure cooperative intervention signal containing the intervention direction and the temperature comprehensive deviation value when the temperature deviation value continuously exceeds the preset allowable deviation range, and sending the pressure cooperative intervention signal to the heat source supply and pressure stabilizing module to request the heat source supply and pressure stabilizing module to finely regulate the pressure set value of the flash tank.
6. The operation control system of a high-efficiency tubular heat exchanger according to claim 5, wherein the process of obtaining the integrated temperature deviation value comprises calculating an average absolute deviation or an integrated absolute error within a set evaluation time window as the integrated temperature deviation value based on two trend curves.
7. The operation control system of a high-efficiency tubular heat exchanger according to claim 6, wherein the heat source supply and pressure stabilizing module performs an intervention condition check after receiving the pressure cooperative intervention signal, confirms that the self pressure is stable and the requested intervention direction is within a safe allowable adjustment range of the flash tank pressure set value, and then performs directional fine adjustment on the flash tank pressure set value in a small fixed step size according to the temperature comprehensive deviation value.
8. The operation control system of a high-efficiency tubular heat exchanger according to claim 4, wherein the temperature and humidity compensation algorithm model is trained according to typical environmental parameters of historical environmental humiture (high temperature and humidity in summer and low temperature and low humidity in winter) to correct the target temperature.

Description

Efficient tubular heat exchanger and operation control system thereof Technical Field The invention relates to the technical field of heat energy recovery of a papermaking drying process, in particular to a high-efficiency tubular heat exchanger and an operation control system thereof. Background In the papermaking drying process, energy consumption is huge, wherein the drying of a dryer is a main energy consumption link, and in order to reduce energy consumption and improve energy efficiency, a heat energy recovery technology is generally adopted in the industry, namely, the waste heat of high-temperature condensed water discharged from the dryer is recovered and used for preheating air to assist in drying paper. Typical recovery systems generally use flash tanks to recover the residual heat of high-temperature condensate water of a drying cylinder, and use a tubular heat exchanger to produce hot air, and then send the hot air back to a drying part for auxiliary drying, wherein the heat of a traditional straight fin is transmitted only through a narrow contact area at the root of the fin, so that the temperature gradient of the fin along the height direction is large, the disturbance capacity to air flow is limited, and the laminar thermal boundary layer closely attached to the surface of the fin is difficult to effectively destroy, which is a main source of air-side thermal resistance, and the overall heat transfer coefficient (K value) is low; in addition, in the papermaking process, on one hand, the pressure of a heat source (flash steam) supplied to a heat exchanger by a flash tank is greatly influenced by the speed and gram weight change of raw paper, fluctuation is severe, so that hot air output is unstable, on the other hand, the actual temperature control of hot air is mostly simple in feedback, the multivariable influences of paper types, environment temperature and humidity and the like are not considered, the precision is poor, the production requirement of high-quality paper cannot be met, and the energy-saving potential is restricted. Therefore, aiming at the practical technical defect, a high-efficiency tubular heat exchanger and an operation control system thereof are provided. Disclosure of Invention The invention aims to solve the problem of practical technical defects and provides a high-efficiency tubular heat exchanger and an operation control system thereof. The invention aims at providing a high-efficiency tubular heat exchanger which comprises a tubular heat exchange structure connected with a flash tank pipeline, wherein the tubular heat exchange structure comprises an S-shaped flow pipe arranged in a heat exchange pipe shell, the S-shaped flow pipe is internally sleeved with an S-shaped heat exchange pipe, a heat exchange space is formed between the S-shaped flow pipe and the S-shaped heat exchange pipe, the S-shaped heat exchange pipe comprises a plurality of straight pipe fin sections which are arranged in parallel and bent pipe straight sections which are arranged at two ends of the straight pipe fin sections, a pair of bent pipe straight sections which are positioned at two ends are respectively externally connected with a heat medium inlet pipe and a heat medium outlet pipe which extend to the outside of the S-shaped flow pipe, and two ends of the S-shaped flow pipe are respectively provided with an exhaust pipe and an exhaust pipe which are externally connected with a drying gas hood; The outer wall of the straight tube fin section is distributed with a plurality of axial flow guide parts which are parallel to the axial direction of the straight tube fin section and are communicated with the inside of the straight tube fin section, and the heat exchange space is provided with spiral fins which are embedded and installed together with the straight tube fin section and the axial flow guide parts. Further, the axial flow guiding part and the straight tube fin segment are axially arranged in parallel and axially protrude, and the nodding section of the axial flow guiding part is of a triangle-like structure which is in arc connection with the outer tube wall of the straight tube fin segment, and comprises an arc connection surface, a long inclined surface and a short inclined surface. Further, the extending direction of the long inclined plane of the axial flow guiding part is matched with the spiral direction of the air flow guided by the spiral fins, the short inclined plane is smoothly transited to the wall of the straight pipe fin section, and the spiral fins are provided with clamping grooves or connecting surfaces matched with the axial flow guiding part in shape and are fixed on the axial flow guiding part in an embedding, welding or brazing mode. Further, the operation control system of the high-efficiency tubular heat exchanger comprises an operation control platform, a heat source supply and pressure stabilizing module and a hot air actual temperature regulating module;