System for calculating actual heat exchange efficiency of Teflon shell-and-tube heat exchanger

Abstract

The utility model discloses a system for calculating the actual heat exchange efficiency of a Teflon shell-and-tube heat exchanger, which is used for being matched with the production of photovoltaic cells, and comprises a steam heating plate heat exchanger, a water tank, a temperature sensor, a temperature sensor, a temperature sensor and a controller, and is characterized in that the user side of the steam heating plate heat exchanger is connected to the water tank to generate 80 DEG C hot water; the hot water with the temperature of 80 DEG C flows out of the water tank and then enters the shell pass end of the Teflon shell-and-tube heat exchanger, and outlet water at the shell pass end flows back to the steam heating plate heat exchanger after passing through a vertical pipeline centrifugal pump, so that shell pass circulation is formed; an outlet of the tube pass end of the Teflon shell-and-tube heat exchanger is connected to a leakage-free fluorine-lined magnetic pipeline pump through a water pipe, and after the pump conveys water flow to a PE water tank, the water flow returns to the tube pass end of the Teflon shell-and-tube heat exchanger again to form tube pass circulation; according to the system, the actual heat exchange efficiency of the Teflon shell-and-tube heat exchanger is calculated by measuring the shell layer temperature difference and the tube pass temperature difference. The system provided by the utility model can accurately calculate the actual heat exchange efficiency of the Teflon shell-and-tube heat exchanger, and provides an efficient and reliable solution for hot water supply and heat exchange links in the production process of photovoltaic cells.

Description

TECHNICAL FIELD

[0001] The utility model discloses a system for calculating the actual heat exchange efficiency of teflon tube bank heat exchanger belongs to heat exchanger technical field. BACKGROUND

[0002] In the production process of photovoltaic cell, two processes of etching and alkali polishing need to use hot water. The traditional heating mode is to heat pure water by a hot water machine and then supply it to the machine table. However, with the increasing demand for energy saving and consumption reduction, heat pump heating gradually becomes a more efficient heating mode. The heat pump can use the process cooling water in the factory area as a heat source to produce high-temperature hot water, and then heat exchange with ultrapure water through a heat exchange unit to meet the needs of etching and polishing process.

[0003] Because the etching and polishing process has very high requirements for water quality, the resistivity of ultrapure water needs to reach 18MΩ*cm, and ordinary metal heat exchangers cannot meet this requirement. Therefore, it is considered to use teflon tube bank heat exchanger. However, the thermal conductivity of teflon is much lower than that of metal, so it is necessary to experimentally analyze the actual heat exchange efficiency of teflon tube bank heat exchanger. INVENTION CONTENTS

[0004] In order to solve the above problems, the utility model discloses a system for calculating the actual heat exchange efficiency of teflon tube bank heat exchanger.

[0005] The technical scheme of the utility model is as follows:

[0006] A system for calculating the actual heat exchange efficiency of teflon tube bank heat exchanger is used to match photovoltaic cell production, comprising:

[0007] A steam heated plate heat exchanger is connected to a water tank on the user side to produce 80℃ hot water;

[0008] The 80℃ hot water flows out of the water tank and enters the shell side end of the teflon tube bank heat exchanger. The outlet water of the shell side end is returned to the steam heated plate heat exchanger after passing through a vertical pipeline centrifugal pump, forming a shell side circulation.

[0009] The tube side end of the teflon tube bank heat exchanger is connected to a leak-free fluorine-lined magnetic pipeline pump through a water pipe. The pump delivers the water flow to a PE water tank, and the water flow returns to the tube side end of the teflon tube bank heat exchanger again, forming a tube side circulation.

[0010] The system calculates the actual heat exchange efficiency of the teflon tube bank heat exchanger by measuring the shell temperature difference and the tube temperature difference.

[0011] Preferably, pressure gauges, thermometers and regulating valves are arranged at the inlet and outlet of the steam heated plate heat exchanger, and at the inlet and outlet of the shell side end and the tube side end of the teflon tube bank heat exchanger.

[0012] Preferably, the conductivity meter is arranged at the inlet and outlet of the tube side end of the Teflon tube heat exchanger to monitor the water conductivity.

[0013] Preferably, the steam inlet of the steam heating plate heat exchanger is connected to the DN159 steam main pipe and accessed through a DN25 branch pipe, and a gate valve, a check valve, a regulating valve, a pressure gauge, a thermometer and a safety valve are arranged on the branch pipe.

[0014] Preferably, the return water pipe of the steam heating plate heat exchanger is accessed to the drain pipe through a DN25 pipe, and a pressure gauge, a thermometer, a check valve, a Y-type filter, a water pump and a drain trap are arranged on the return water pipe.

[0015] Preferably, in the circulation loop between the tube side end of the Teflon tube heat exchanger and the PE water tank, ultrapure water is filled to meet the requirement of the water resistivity of 18MΩ*cm for the wafering and polishing processes.

[0016] Preferably, all the water pumps in the system are operated at a fixed frequency, and the actual heat exchange efficiency of the Teflon tube heat exchanger is calculated by measuring the shell temperature difference and the tube temperature difference and using the related heat exchange theory.

[0017] The system has the advantages that:

[0018] The system can accurately calculate the actual heat exchange efficiency of the Teflon tube heat exchanger, and provides an efficient and reliable solution for the hot water supply and heat exchange link in the photovoltaic cell production process. Meanwhile, the system also has water quality monitoring and control functions, ensures that the water quality meets the process requirements, and improves the production efficiency and product quality. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic view of the utility model. DETAILED DESCRIPTION

[0020] The utility model will be further described below in combination with the drawings. The following examples are only used to more clearly illustrate the technical scheme of the utility model, and cannot limit the protection scope of the utility model.

[0021] Example:

[0022] The wafering and alkali polishing processes in the photovoltaic cell production process need to use hot water, and the current heating mode is that the pure water is prepared and then heated by a hot water machine to supply the machine table. The parameters are as follows:

[0023]

[0024] Note: The temperature difference between summer and winter results in different pure water inlet temperatures.

[0025] The average monthly electricity consumption of the hot water machine per day:

[0026]

[0027]

[0028] Note: The power consumption of the hot water machine for heating in winter: pure water temperature 5℃ to 65℃. The power consumption of the hot water machine for heating in summer: pure water temperature 20℃ to 80℃.

[0029] Now consider using heat pump heating, the heat source is taken from the process cooling water in the factory area (outlet water 19.5℃, return water 22.2℃, flow 1700m3 / h). The heat pump produces 85℃ high temperature hot water, which is heated by the heat exchanger and enters the main machine of the polishing process, and completes the follow-up process production.

[0030] The polishing and polishing process requires the resistivity of ultrapure water to reach 18MΩ*cm, ordinary metal heat exchanger cannot meet the requirements, now consider using Teflon material tube heat exchanger, because the thermal conductivity of Teflon is about 0.25-0.35W / m*K, which is much lower than that of metal (the thermal conductivity of metal is 40W / (m·k)), so the actual heat exchange efficiency of Teflon tube heat exchanger needs to be analyzed.

[0031] As shown in Figure 1 , a 200KW tube heat exchanger with Teflon coating is used, and the relevant experiments and analysis are completed by relying on the site conditions of the flue gas waste heat recovery project (2-3 kilograms of saturated steam produced by the waste heat boiler).

[0032] A DN25 branch pipe is connected to the steam main pipe, and the branch pipe enters the steam heating plate heat exchanger 1; a gate valve is provided on the branch pipe, and a check valve, a regulating valve, a pressure gauge, a thermometer and a safety valve are sequentially arranged before entering the plate heat exchanger. The DN25 return water pipe on the plate heat exchanger side is connected to the drain pipe, and a pressure gauge, a thermometer, a check valve, a Y-type filter, a water pump and a drain are sequentially arranged on the plate heat exchanger side.

[0033] The user side of the steam heating plate heat exchanger 1 outputs 80℃ hot water, which first enters the water tank 2 with a volume of 6m 3 , and then enters the Teflon tube heat exchanger 3 shell side after coming out of the water tank 2. The water outlet of the shell side passes through a vertical pipeline centrifugal pump 4 with a flow rate of Q=20m 3 / h, and then enters the steam heating plate heat exchanger 1. The inlet and outlet of the steam heating plate heat exchanger 1 and the inlet and outlet of the tube heat exchanger shell side are provided with pressure gauges, thermometers and regulating valves.

[0034] The DN70 water pipe at the outlet of the Teflon tube heat exchanger 3 tube side is connected to a Q=20m 3HCLF leakproof fluorine lining magnetic pipeline pump 5 enters 6 m 3 PE water tank 6, and returns to the tube side of the Teflon shell-and-tube heat exchanger 3, wherein the tube side of the Teflon shell-and-tube heat exchanger 3 is provided with pressure gauges, thermometers, regulating valves and conductivity meters.

[0035] The water pipe of the Teflon shell-and-tube heat exchanger 3 is made of steel pipe with Teflon coating on the inner wall, and the PE water tank 6 is filled with ultrapure water.

[0036] All the water pumps in the system are operated at a constant frequency, the actual heat exchange efficiency of the Teflon shell-and-tube heat exchanger is obtained by measuring the shell temperature difference and the tube temperature difference and using relevant heat exchange theory calculation.

[0037] The above is only the preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A system for calculating the actual heat exchange efficiency of a Teflon tube heat exchanger, used in conjunction with photovoltaic cell production, characterized in that, include: A steam-heated plate heat exchanger, with its user side connected to a water tank to produce hot water at 80°C; After the 80°C hot water flows out of the water tank, it enters the shell side of the Teflon tube heat exchanger. The water from the shell side flows back to the steam-heated plate heat exchanger after passing through a vertical pipeline centrifugal pump, forming a shell-side circulation. The tube side of the Teflon tube heat exchanger is connected to a leak-free fluoropolymer-lined magnetic pipeline pump via a water pipe. The pump delivers water to a PE water tank, and the water then returns to the tube side of the Teflon tube heat exchanger, forming a tube-side circulation. The system calculates the actual heat exchange efficiency of the Teflon tube heat exchanger by measuring the shell temperature difference and the tube-side temperature difference.

2. The system according to claim 1, characterized in that, Pressure gauges, thermometers, and regulating valves are installed at the inlet and outlet of steam-heated plate heat exchangers, and at the inlet and outlet of the shell side and tube side of Teflon tube heat exchangers.

3. The system according to claim 1, characterized in that, Conductivity meters are also installed at the inlet and outlet of the tube side of the Teflon tube heat exchanger to monitor the conductivity of the water.

4. The system according to claim 1, characterized in that, The steam inlet of the steam-heated plate heat exchanger is connected to the DN159 main steam pipe and then to the DN25 branch pipe. The branch pipe is equipped with a gate valve, check valve, regulating valve, pressure gauge, thermometer and safety valve.

5. The system according to claim 1, characterized in that, The return water pipe of the steam-heated plate heat exchanger is connected to the drain pipe through a DN25 pipe. The return water pipe is equipped with a pressure gauge, thermometer, check valve, Y-type filter, water pump and drain condensate.

6. The system according to claim 1, characterized in that, The circulation loop between the tube side of the Teflon tube heat exchanger and the PE water tank is filled with ultrapure water to meet the requirement of a water resistivity of 18 MΩ*cm for the texturing and polishing processes.

7. The system according to claim 1, characterized in that, All water pumps in the system operate at a fixed frequency. By measuring the shell temperature difference and tube temperature difference, and using relevant heat exchange theories, the actual heat exchange efficiency of the Teflon tube heat exchanger is obtained.

Images