TWI440805B - A variable pipe heat exchanger - Google Patents

Description

Reducer line heat exchanger

The invention relates to a water heater, in particular to a heat exchanger in a water heater.

The device that regulates the temperature of the air is called an air conditioner. The performance of these air conditioners is formulated for the unit. The air conditioner hot water machine (also known as the heat pump water heater) integrates the refrigeration, heating and hot water, and does not damage the performance of the existing air conditioner. , can also play a good hot water effect and safety and reliability. However, the air conditioner hot water machine refrigerant hot water machine on the market now has the following problems:

Because the general air-conditioning water heater has a small power, it can't be heated once, that is, 15 ° C into the water and 60 ° C out of the water. Therefore, most of them use the loop type heat pump, but the loop type heat pump has certain problems: if the temperature rises, the unit's condensing temperature, exhaust temperature, exhaust pressure and operating current will rise, when the water temperature rises. When the temperature is above 45 °C, the temperature difference between water and working fluid becomes smaller, and the heat absorption capacity becomes worse, resulting in a greatly reduced heat exchange efficiency. In fact, due to the problem of water mixing, the medium-temperature loop-type heat pump water heater has been in a medium-high temperature loop for a long time, resulting in a long-time overload operation of the compressor, resulting in low efficiency, high energy consumption, and even shortened the service life of the compressor.

In order to overcome the deficiencies of the prior art, the present invention provides a variable diameter pipeline heat exchanger with high efficiency and low energy consumption.

The technical solution adopted by the present invention to solve the technical problem thereof is:

A variable-diameter pipeline heat exchanger includes a heat exchange tube and a refrigerant disposed in the heat exchange tube, the heat exchange tube including an outer tube and an inner tube disposed in the outer tube, the inner tube including a first tube a conduit and a second conduit communicating with the first conduit, and an inner diameter of the first conduit is smaller than an inner diameter of the second conduit, the refrigerant being The first conduit flows to the second conduit, wherein the outer tube forms a first flow space and a second flow space with the first conduit and the second conduit, respectively, the first flow space being larger than the second flow space.

A transition tube is disposed at the junction of the first conduit and the second conduit.

The inner tube is provided with a middle tube, and an inner wall of the middle tube is in close contact with an outer wall of the inner tube.

At least one petal piece is disposed between the outer tube and the middle tube, and the flower piece is provided with an overflow hole.

The refrigerant inlet end of the first conduit is provided with a buffer boosting device, and the refrigerant inlet end of the first conduit is connected to the refrigerant output end of the buffer boosting device.

The beneficial effect of the present invention is that the inner tube of the present invention comprises a first conduit and a second conduit communicating with the first conduit, and the inner diameter of the first conduit is smaller than the inner diameter of the second conduit, when the refrigerant is high temperature and high pressure gas When flowing in a conduit, the diameter of the first conduit is small, so that the flow velocity is fast, and a larger number of Lei Sisno is obtained, and when flowing in the second conduit, the heat is mostly conducted out, so that there is more The liquid is present, and the second conduit has a large diameter, so that the generated liquid can accelerate the flow away, thereby avoiding the majority of the area of the heat exchanger being in an inefficient condensation state; the petal piece is disposed between the outer tube and the middle tube of the present invention. The petal piece is provided with a flow hole, thereby increasing water disturbance and enhancing the heat exchange effect; the refrigerant inlet end of the first pipe is connected to the refrigerant output end of the supercharging device, and the pressurization device can pressurize The refrigerant split is more uniform.

Through the improvement of the above structure, the invention can also perform one heating in the case of low power. When the temperature, pressure and flow rate are the same, when the refrigerant enters the heat exchanger, the length of the pipe required for the same heat is generally One-half of the heat exchanger not only saves material costs, but also reduces heat exchanger size.

Referring to FIG. 1 to FIG. 3, the present invention discloses a variable diameter pipeline heat exchanger comprising a heat exchange tube 9 and a refrigerant disposed in the heat exchange tube 9, the heat exchange tube 9 including an outer tube 1 and a An inner tube in the outer tube 1 , the inner tube includes a first tube 2 and a second tube 3 communicating with the first tube 2 , and the inner diameter of the first tube 2 is smaller than the inside of the second tube 3 The refrigerant flows from the first conduit 2 to the second conduit 3. The outer tube 1 forms a first flow space and a second flow space with the first duct 2 and the second duct 3, respectively. The capacity of the first flow space is the size of the outer tube 1 minus the capacity of the first duct 2, and the capacity of the second flow space is the outer tube 1 minus the capacity of the second duct 3. Wherein the first flow space is larger than the second flow space.

In the present embodiment, a connection duct 4 is provided at the junction of the first duct 2 and the second duct 3, and the transition duct 4 can reduce the resistance of the duct wall to the formation of the refrigerant flow during the variable diameter and thus And the resulting spoiler. The inner tube is provided with a middle tube 5, and an inner wall of the middle tube 5 is in close contact with an outer wall of the inner tube, and the refrigerant flows in the double-walled tube to provide protection against leakage of the refrigerant. At least one petal piece 8 is disposed between the outer tube 1 and the middle tube 5, and the flower piece 8 is provided with an overflow hole 7, thereby increasing water disturbance and enhancing the heat exchange effect.

The refrigerant inlet end of the first conduit 2 is provided with a buffer boosting device 6, and the refrigerant inlet end of the first conduit 2 is connected to the refrigerant output end of the buffer boosting device 6, and the buffer boosting device 6 can The refrigerant is split more uniformly, and the pressure of the refrigerant into the independent variable diameter micro-tube heat exchanger is increased to increase the heat transfer coefficient.

The working principle of the invention is as follows: since the diameter of the casing of the independent variable diameter micro-tube heat exchanger is fine, the flow rate of the refrigerant and water is increased under the same flow rate, and a large Reynolds number can be obtained, and the thickness of the liquid refrigerant is reduced. As a result, the thickness of the stagnant layer is greatly reduced, so the heat transfer coefficient can be greatly improved, so that the heat transfer rate is faster. Increasing the diameter of the tube at the end of the refrigerant channel helps to allow the condensate to flow out as quickly as possible. The refrigerant condenses heat in the heat exchanger, and condenses from the imported superheated or saturated high-temperature and high-pressure gas to the outlet inside the tube. Saturated or subcooled liquid. The presence of the condensate hinders the contact of the high temperature and high pressure gas with the wall surface of the tube and becomes the main thermal resistance of the condensation heat transfer. Due to the closer the end, the more the proportion of condensed liquid, the larger the diameter of the condensing duct can reduce the flow resistance, and the condensed liquid is accelerated to flow out. Since the fluid is viscous, internal friction is generated during flow, and flow resistance is formed. According to Fanning's formula and Newton's law of viscosity, when the laminar flow is inferred, the pressure drop is inversely proportional to the square of the diameter of the refrigerant channel.

In the case of complete turbulence, the flow resistance is only proportional to the square of the velocity. The pipe diameter is increased and the flow rate of the condensate is slowed down. The flow resistance or pressure drop is reduced in laminar or turbulent flow, so the flow rate is reduced. Slow will be significantly reduced. This kind of segmentation widening, increasing the flow rate, and reducing the low pressure drop design makes the heat exchange time longer when the refrigerant is in the high temperature and high pressure gas dominant stage, and accelerates the flow away when more condensed liquid is generated, avoiding the heat exchanger being large. Part of the area is in an inefficient condensation process. Moreover, a petal piece is arranged between the outer tube and the middle tube, and the flower piece is provided with a flow hole, the petal piece and the overflow hole can increase the disturbance of the water, and the heat exchange effect is enhanced by the disturbance.

By using the improved heat exchanger, even a small power refrigerant hot water machine can achieve one heating. When the refrigerant enters the heat exchanger, when the temperature, pressure and flow rate are the same, the pipe length required to make the same heat is one-half of that of the general heat exchanger. This not only saves material costs but also reduces heat exchanger size.

Outer tube

2‧‧‧First catheter

3‧‧‧Second catheter

4‧‧‧Transition tube

5‧‧‧中管

6‧‧‧buffer booster

7‧‧‧Overcurrent

8‧‧‧petal tablets

9‧‧‧ heat exchange tube

The invention will now be further described with reference to the drawings and embodiments.

1 is a cross-sectional view of the present invention; FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1; and FIG. 3 is an overall view of the present invention.

1‧‧‧External management

2‧‧‧First catheter

3‧‧‧Second catheter

4‧‧‧Transition tube

5‧‧‧中管

7‧‧‧Overcurrent

8‧‧‧petal tablets

Claims (5)

A variable-diameter pipeline heat exchanger includes a heat exchange tube and a refrigerant disposed in the heat exchange tube, the heat exchange tube including an outer tube and an inner tube disposed in the outer tube, the inner tube including a first tube a conduit and a second conduit communicating with the first conduit, and an inner diameter of the first conduit is smaller than an inner diameter of the second conduit, the refrigerant flowing from the first conduit to the second conduit, wherein: the outer The tube and the first conduit and the second conduit respectively form a first flow space and a second flow space, the first flow space being larger than the second flow space. A reducer heat exchanger according to claim 1, wherein a transition tube is provided at the junction of the first conduit and the second conduit. A reducer heat exchanger according to claim 1, wherein the inner pipe is provided with a middle pipe, and an inner wall of the inner pipe is in close contact with an outer wall of the inner pipe. The variable-diameter heat exchanger according to claim 3, wherein at least one petal piece is disposed between the outer tube and the middle tube, and the petal piece is provided with an overflow hole. The variable-diameter heat exchanger of claim 1, wherein the refrigerant inlet end of the first conduit is provided with a buffer pressurization device, and the refrigerant inlet end of the first conduit is coupled to the buffer The refrigerant output of the boosting device is connected.