Expansion joint for high-temperature pipeline

Abstract

The expansion joint comprises a corrugated pipe (5), a left connecting pipe (9) and a right connecting pipe (10) are welded to the left end and the right end of the corrugated pipe in a sealed mode respectively, and the expansion joint is characterized in that a left annular plate (2) is welded to the left connecting pipe in a sealed mode, a right annular plate (8) is welded to the right connecting pipe in a sealed mode, the left annular plate and the right annular plate are sleeved with an outer pipe (4), and the right end of the outer pipe is welded to the right annular plate in a sealed mode; a sealing ring (3) is arranged between the outer pipe and the left annular plate, a water inlet (1) is formed in the left annular plate, a water outlet is formed in the right annular plate, and a valve (11) is installed on the water outlet and is a pressure valve. The corrugated pipe has the beneficial effects that 1, a heat insulation sleeve is omitted, so that the corrugated pipe is prevented from being damaged due to loss of a heat insulation material; cooling water makes full contact with the corrugated pipe, all parts of the corrugated pipe are cooled evenly, and the problems of high temperature and redness of the corrugated pipe are solved; 3, the consumption of cooling water can be reduced, and the heat loss of the pipeline can be reduced.

Description

Technical Field

[0001] The invention relates to an expansion joint for a high-temperature pipeline. Background Art

[0002] In order to absorb the thermal expansion displacement of the high-temperature pipeline, it is necessary to set an expansion joint on the high-temperature pipeline. The expansion joint includes a bellows. The two ends of the bellows are respectively connected to an inner pipe, the inner pipe is located in the bellows, and the inner pipe is provided with an insulation sleeve made of insulation material. The opposite ends of the inner pipe are overlapped and have expansion joints. The expansion and contraction of the bellows or the vibration of the pipeline can easily cause the insulation material of the insulation sleeve to be lost, the expansion joint becomes larger, and the high-temperature medium passes through the expansion joint and contacts the bellows. The bellows is the weakest link in the pipeline system and has a high probability of problems. The high-temperature medium contacts the bellows, causing the bellows to turn red due to the high temperature and accelerate fatigue.

[0003] In order to prevent the bellows from turning red due to high temperature, some people have proposed wrapping a water pipe around the bellows to cool it. However, the disadvantage is that the water pipe cannot fully contact the bellows, and some parts of the bellows are still damaged by high temperature. In addition, the cooling water consumption is large. Summary of the invention

[0004] In view of the above problems, the present invention proposes an expansion joint for high-temperature pipes, which eliminates heat insulation materials, cools the bellows by direct contact between water and the bellows, absorbs heat from the bellows, and prevents the bellows from being damaged by high temperature.

[0005] The technical solution of the present invention is an expansion joint for high-temperature pipelines, which includes a bellows 5, and the left and right ends of the bellows are respectively sealed and welded with a left connecting pipe 9 and a right connecting pipe 10, and the characteristic is that a left ring plate 2 is sealed and welded on the left connecting pipe 9, and a right ring plate 8 is sealed and welded on the right connecting pipe, an outer tube 4 is sleeved on the left and right ring plates, the right end of the outer tube is sealed and welded to the right ring plate, a sealing ring 3 is provided between the outer tube and the left ring plate, a water inlet 1 is provided on the left ring plate, a water outlet is provided on the right ring plate, and a valve 11 is installed on the water outlet.

[0006] The working principle of the present invention is that the left ring plate, the right ring plate, the bellows and the outer tube form a cavity, the cavity is filled with cooling water, the heat on the bellows is absorbed by the cooling water, and the bellows is prevented from being damaged by high temperature.

[0007] Compared with the prior art, the present invention has the following advantages: 1. The heat insulation sleeve is eliminated, and there is no risk of damage to the bellows due to the loss of heat insulation material; 2. The cooling water is in full contact with the bellows, and all parts of the bellows are evenly cooled, thus avoiding the problem of high temperature and reddening of the bellows; 3. The consumption of cooling water can be reduced, and the heat energy loss of the pipeline can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural schematic diagram of the present invention.

[0009] Figure 2 This is the schematic diagram of the temperature controller circuit.

[0010] Figure symbols: 1-water inlet, 2-left ring plate, 3-sealing ring, 4-outer tube, 5-bellows, 6-left casing, 7-right casing, 8-right ring plate, 9-left connecting pipe, 10-right connecting pipe, 11-valve, 12-temperature sensor. DETAILED DESCRIPTION

[0011] An expansion joint for a high-temperature pipeline comprises a bellows 5, with a left connecting pipe 9 and a right connecting pipe 10 respectively sealed and welded at the left and right ends of the bellows. The invention is characterized in that a left ring plate 2 is sealed and welded on the left connecting pipe 9, a right ring plate 8 is sealed and welded on the right connecting pipe, an outer pipe 4 is sleeved on the left and right ring plates, the right end of the outer pipe is sealed and welded to the right ring plate, a sealing ring 3 is provided between the outer pipe and the left ring plate, a water inlet 1 is provided on the left ring plate, a water outlet is provided on the right ring plate, and a valve 11 is installed on the water outlet.

[0012] The left ring plate, the right ring plate, the outer tube and the bellows form a cavity. Cooling water enters the cavity through the water inlet, absorbs the heat of the bellows, and is discharged from the water outlet.

[0013] The function of the sealing ring is to prevent cooling water from leaking between the left ring plate and the outer tube.

[0014] To further protect the bellows, a left sleeve 6 is connected to the left connecting pipe, the right end of the left sleeve is close to the right connecting pipe, and a right sleeve 7 is connected to the right connecting pipe, the left end of the right sleeve is close to the left connecting pipe, and the right sleeve extends into the left sleeve; in this way, the high-temperature medium must pass through the gap channel between the left sleeve and the right sleeve to directly contact the bellows. The gap channel has a thermal resistance function. The longer the gap channel is, the greater the thermal resistance formed is.

[0015] Its working principle is that the expansion joint is connected in series in the pipeline. When the pipeline is axially displaced, the bellows will expand and contract accordingly to compensate for the displacement of the pipeline. The water inlet is connected to the cooling water source, and the valve opening is adjusted to make the water outflow less than the water inflow, so that the cooling water fills the outer pipe. The cooling water absorbs the heat on the bellows to avoid the problem of high temperature and redness of the bellows.

[0016] In order to reduce water consumption, the valve is a pressure valve. When the pressure in the outer tube is lower than the set value, the pressure valve is closed. When the pressure in the outer tube is greater than the set value, the pressure valve is closed and opened. The principle is that after the cooling water in the outer tube absorbs the heat on the bellows, its temperature will rise, and the pressure in the outer tube will also rise. When the pressure in the outer tube is greater than the set value, the pressure valve is closed and opened, hot water flows out, cooling water enters, the water temperature in the outer tube decreases, the pressure in the outer tube also decreases, and the pressure valve is closed.

[0017] In order to further reduce water consumption and reduce the heat energy loss of the medium in the pipeline, the valve is a solenoid valve, which is controlled by a temperature controller. The temperature controller includes a temperature sensor (thermocouple) for detecting water temperature. The output end of the temperature sensor is connected to the input end of the amplifier. The output end of the amplifier is connected to the inverting input end of the operational amplifier A1 through a resistor R1. The non-inverting input end of the operational amplifier A1 is connected to the DC power supply VDD through a resistor R2. The non-inverting input end of the operational amplifier A1 is grounded through a resistor R3. A resistor R4 is connected between the non-inverting input end of the operational amplifier A1 and the output end of the operational amplifier A1. The output end of the operational amplifier A1 is connected to the base of the transistor T1 through a resistor R5. The emitter of the transistor T1 is grounded. The collector of the transistor T1 is connected to the DC power supply VDD through the coil J1 of the DC relay. The coil J1 is connected in parallel with a diode D1. The cathode of the diode is connected to the DC power supply VDD. The contacts of the DC relay control the on and off of the solenoid valve.

[0018] The resistance values ​​of resistors R2, R3 and R4 are equal. Resistors R2, R3 and R4 provide reference voltage for operational amplifier A1. When the output of operational amplifier A1 is at a low level, the reference voltage is 1 / 3 of the voltage value of the DC power supply VDD. When the output of operational amplifier A1 is at a high level, the reference voltage is 2 / 3 of the voltage value of the DC power supply VDD. Initially, the output of operational amplifier A1 is at a high level. When the water temperature rises to the maximum value, the signal voltage of the inverting input of operational amplifier A1 is greater than the voltage of the non-inverting input. The output of operational amplifier A1 becomes low, transistor T1 is turned on, coil J1 is energized, the contacts of the DC relay are closed, the solenoid valve is opened, hot water flows out, cooling water enters, and the water temperature decreases. When the water temperature drops to the minimum value, the signal voltage of the inverting input of operational amplifier A1 is lower than the voltage of the non-inverting input. The output of operational amplifier A1 becomes high, transistor T1 is turned off, coil J1 loses power, the contacts of the DC relay are disconnected, the solenoid valve is closed, no hot water flows out, and the water temperature rises.

[0019] The temperature control principle is that the amplifier amplifies the output signal of the temperature sensor, and the operational amplifier A1 compares the temperature signal with the reference voltage. The reference voltage has two different values, namely, the value when the output end of the operational amplifier A1 is high (reference voltage 1) and the value when the output end of the operational amplifier A1 is low (reference voltage 0). When the temperature signal is greater than the reference voltage 1, the operational amplifier A1 outputs a high level, the transistor T1 is turned on, the coil J1 is energized, the contacts of the DC relay are closed, the solenoid valve is opened, the hot water flows out, the cooling water enters, and the water temperature decreases; When the temperature signal is less than the reference voltage 0, the operational amplifier A1 outputs a low level, the transistor T1 is cut off, the coil J1 loses power, the contacts of the DC relay are disconnected, the solenoid valve is closed, no hot water flows out, and the water temperature rises; The technical effect is that the water in the outer pipe is maintained within a certain temperature range, which will not make the bellows red and can reduce the loss of heat energy in the pipeline.

Claims

1. An expansion joint for a high-temperature pipeline, comprising a bellows (5), the left and right ends of the bellows being respectively sealed and welded with a left connecting pipe (9) and a right connecting pipe (10), wherein: A left annular plate (2) is seal-welded to the left connecting pipe 9, a right annular plate (8) is seal-welded to the right connecting pipe, an outer pipe (4) is sleeved on the left and right annular plates, the right end of the outer pipe is seal-welded to the right annular plate, a sealing ring (3) is provided between the outer pipe and the left annular plate, a water inlet (1) is provided on the left annular plate, a water outlet is provided on the right annular plate, and a valve (11) is installed on the water outlet.

2. The expansion joint for high temperature pipeline according to claim 1, characterized in that: A left sleeve (6) is connected to the left connecting pipe, the right end of the left sleeve is close to the right connecting pipe, a right sleeve (7) is connected to the right connecting pipe, the left end of the right sleeve is close to the left connecting pipe, and the right sleeve extends into the left sleeve.

3. The expansion joint for high temperature pipeline according to claim 1, characterized in that: The valve is a pressure valve.

4. The expansion joint for high temperature pipeline according to claim 1, characterized in that: The valve is a solenoid valve, which is controlled by a temperature controller (12). The temperature controller includes a temperature sensor for detecting water temperature. The output end of the temperature sensor is connected to the input end of an amplifier. The output end of the amplifier is connected to the inverting input end of an operational amplifier A1 through a resistor R1. The non-inverting input end of the operational amplifier A1 is connected to a DC power supply VDD through a resistor R2. The non-inverting input end of the operational amplifier A1 is grounded through a resistor R3. A resistor R4 is connected between the non-inverting input end of the operational amplifier A1 and the output end of the operational amplifier A1. The output end of the operational amplifier A1 is connected to the base of a transistor T1 through a resistor R5. The emitter of the transistor T1 is grounded. The collector of the transistor T1 is connected to the DC power supply VDD through a coil J1 of a DC relay. The coil J1 is connected in parallel with a diode D1. The cathode of the diode is connected to the DC power supply VDD. The contacts of the DC relay control the on and off of the solenoid valve.

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