Finned tube heat exchanger and air-cooled total heat recovery unit

Abstract

This utility model provides a finned tube heat exchanger and an air-cooled total heat recovery unit, belonging to the field of heat exchanger technology. It includes a hot water inlet pipe and a hot water outlet pipe, connected by multiple sets of hot water heat exchange tubes. Each of the multiple sets of hot water heat exchange tubes is fitted with a refrigerant heat exchange tube. One end of each set of refrigerant heat exchange tubes is connected to a liquid refrigerant outlet pipe via a first pipe, and the other end is connected to a gas refrigerant inlet pipe via a second pipe. Through the fitted structure of the hot water heat exchange tubes and refrigerant heat exchange tubes, the heat of the high-temperature, high-pressure refrigerant gas can be released through either air cooling or hot water heat exchange, simplifying the refrigerant circulation system and solving the problem of high cost in traditional units.

Description

Technical Field

[0001] This utility model belongs to the field of heat exchanger technology, and more specifically, it relates to a finned tube heat exchanger and an air-cooled total heat recovery unit. Background Technology

[0002] In the field of refrigeration and heating, air-cooled total heat recovery chillers are widely used in commercial buildings, industrial production and other scenarios because of their ability to both cool and recover heat to produce hot water.

[0003] Existing air-cooled total heat recovery chiller units on the market use a dual-condenser system to achieve function switching. When the system does not require heat recovery, the high-temperature and high-pressure refrigerant gas enters the air-cooled condenser and directly releases the heat into the environment through heat exchange with the atmosphere. However, when heat recovery is required to produce hot water, the water-cooled condenser is activated, using water as a medium to recover the heat from the refrigerant gas. This working mode relies on an electric three-way valve to switch the refrigerant flow direction, allowing the high-temperature and high-pressure refrigerant gas to flow selectively between the air-cooled and water-cooled condensers. Its unit structure and refrigerant circulation system are complex, resulting in higher costs. Summary of the Invention

[0004] To address the aforementioned technical problems, this utility model provides a finned tube heat exchanger and an air-cooled total heat recovery unit to solve the problems existing in the prior art. Traditional units are usually equipped with air-cooled condensers, water-cooled condensers, and electric three-way valves, which are switched by the electric three-way valves. The unit structure and refrigerant circulation system are complex, resulting in high costs.

[0005] The purpose and effectiveness of this utility model—a finned tube heat exchanger and an air-cooled total heat recovery unit—are achieved through the following specific technical means:

[0006] A finned tube heat exchanger includes a hot water inlet pipe and a hot water outlet pipe, wherein multiple sets of hot water heat exchange tubes are provided between the hot water inlet pipe and the hot water outlet pipe for communication.

[0007] Each of the multiple sets of hot water heat exchange tubes is fitted with a refrigerant heat exchange tube. One end of each of the multiple sets of refrigerant heat exchange tubes is connected to a refrigerant liquid outlet pipe through a first pipe, and the other end of each of the multiple sets of refrigerant heat exchange tubes is connected to a refrigerant gas inlet pipe through a second pipe.

[0008] According to a preferred embodiment, the two ends of the multiple sets of refrigerant heat exchange tubes are respectively installed on two sets of heat exchanger end plates, and multiple sets of air-cooled fins are equidistantly arranged between the two sets of heat exchanger end plates.

[0009] A wind-cooled total heat recovery unit includes a finned tube heat exchanger as described above, wherein a variable frequency fan is provided on one side of the finned tube heat exchanger, and a magnetic levitation centrifugal compressor and a flooded evaporator are provided on the other side of the finned tube heat exchanger.

[0010] According to a preferred embodiment, the refrigerant liquid outlet pipe on the finned tube heat exchanger is connected to the magnetically levitated centrifugal compressor and the electronic expansion valve.

[0011] According to a preferred embodiment, the flooded evaporator is provided with a chilled water inlet pipe at one end and a chilled water outlet pipe at the other end.

[0012] An electronic expansion valve is installed between the refrigerant liquid outlet pipe and the flooded evaporator.

[0013] According to a preferred embodiment, one end of the magnetically levitated centrifugal compressor is connected to the flooded evaporator, and the other end is connected to the refrigerant gas inlet pipe on the finned tube heat exchanger.

[0014] According to a preferred embodiment, a hot gas bypass valve is provided on one side of the flooded evaporator, and a one-way valve for connection is provided on one side of the refrigerant gas inlet pipe. One end of the one-way valve is connected to the magnetic levitation centrifugal compressor and the hot gas bypass valve.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. By using a nested structure of hot water heat exchange tubes and refrigerant heat exchange tubes, the heat of the high-temperature and high-pressure refrigerant gas can be released through either air cooling or hot water heat exchange, replacing the original dual condenser switching system. At the same time, the refrigerant heat exchange tubes are installed at both ends on the heat exchanger end plates, which, together with the air-cooled fins, further enhance the heat exchange function. This simplifies the refrigerant circulation system and solves the problem of high cost in traditional units.

[0017] 2. The air-cooled total heat recovery unit based on a finned tube heat exchanger can achieve three operating modes: no heat recovery, total heat recovery, and partial heat recovery. In the no heat recovery mode, when the user is not using hot water, the variable frequency fan runs at full speed, and the high-temperature, high-pressure refrigerant exhaust heat is completely dissipated into the atmosphere through the air-cooled fins, meeting the simple cooling demand. In the total heat recovery mode, when the user is using hot water at full load, the variable frequency fan stops running, and the hot water flows through the hot water heat exchange tube to absorb the refrigerant exhaust heat, achieving efficient heat recovery to produce hot water. The partial heat recovery mode is suitable for scenarios where the user uses hot water at partial load. The variable frequency fan runs at partial speed, and part of the refrigerant exhaust heat is dissipated through the air-cooled fins, while the rest is used to heat the hot water. The flexible switching between the three modes can be adjusted according to the user's actual needs and changes in operating conditions, greatly improving the unit's applicability and energy utilization efficiency, and avoiding the energy loss and system instability problems caused by the frequent switching of condensers under different operating conditions in traditional units. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the finned tube heat exchanger of this utility model;

[0019] Figure 2 This is a front view of the finned tube heat exchanger of this utility model;

[0020] Figure 3 yes Figure 2 Sectional view of AA;

[0021] Figure 4 This is a schematic diagram of the structure of the wind-cooled total heat recovery unit of this utility model.

[0022] In the diagram, the correspondence between component names and drawing numbers is as follows:

[0023] 11. Air-cooled fins; 12. Hot water heat exchanger tubes; 13. Refrigerant heat exchanger tubes; 14. Heat exchanger end plate; 15. Hot water inlet pipe; 16. Refrigerant gas inlet pipe; 17. Refrigerant liquid outlet pipe; 18. Hot water outlet pipe; 20. Variable frequency fan; 21. Electronic expansion valve; 22. Flooded evaporator; 23. Magnetic levitation centrifugal compressor; 24. Hot gas bypass valve; 25. One-way valve; 26. Chilled water inlet pipe; 27. Chilled water outlet pipe. Detailed Implementation

[0024] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0025] Example:

[0026] As attached Figure 1 To be continued Figure 3 As shown:

[0027] This utility model provides a finned tube heat exchanger, including a hot water inlet pipe 15 and a hot water outlet pipe 18, with multiple sets of hot water heat exchange tubes 12 connected between the hot water inlet pipe 15 and the hot water outlet pipe 18.

[0028] Multiple sets of hot water heat exchange tubes 12 are fitted with refrigerant heat exchange tubes 13, forming a sleeve-type structure. One end of each set of refrigerant heat exchange tubes 13 is connected to the refrigerant liquid outlet pipe 17 through a first pipe, and the other end is connected to the refrigerant gas inlet pipe 16 through a second pipe. In actual operation, high-temperature and high-pressure refrigerant gas enters the refrigerant heat exchange tubes 13 from the refrigerant gas inlet pipe 16. After heat exchange, it flows out from the refrigerant liquid outlet pipe 17 in the form of high-temperature and high-pressure refrigerant liquid. This sleeve structure of hot water heat exchange tubes 12 and refrigerant heat exchange tubes 13 changes the traditional working mode of relying on dual condenser switching. It integrates the heat release path of high-temperature and high-pressure refrigerant gas, which can be achieved by either air cooling or hot water heat exchange. This simplifies the refrigerant circulation system, reduces the number of equipment components, and lowers the unit cost.

[0029] Please see as follows Figure 1 and Figure 2 As shown, multiple sets of refrigerant heat exchange tubes 13 are respectively installed on two sets of heat exchanger end plates 14 at both ends. Multiple sets of air-cooled fins 11 are equidistantly arranged between the two sets of heat exchanger end plates 14. The heat exchange function is further enhanced by the multiple sets of air-cooled fins 11. The two ends of the multiple sets of refrigerant heat exchange tubes 13 are respectively fixedly installed on two sets of heat exchanger end plates 14. The heat exchanger end plates 14 support the refrigerant heat exchange tubes 13. Multiple sets of air-cooled fins 11 are equidistantly distributed between the two sets of heat exchanger end plates 14. When the system is in a non-heat recovery mode or a partial heat recovery mode and requires air cooling, the outside air flows through the air-cooled fins 11 under the action of the variable frequency fan 20. The air-cooled fins 11 increase the contact area between the refrigerant heat exchange tubes 13 and the air, promote heat exchange, and dissipate the heat of the refrigerant gas in the refrigerant heat exchange tubes 13 to the surrounding environment. In conjunction with the multiple sets of air-cooled fins 11, the heat exchange performance of the heat exchanger under air cooling conditions is further improved.

[0030] As attached Figure 4As shown: This utility model also provides an air-cooled total heat recovery unit, including the aforementioned finned tube heat exchanger. A variable frequency fan 20 is provided on one side of the finned tube heat exchanger. The variable frequency fan 20 can adjust the speed and control the air flow according to the system operation requirements, thereby adjusting the air-cooling heat dissipation effect of the heat exchanger. A magnetic levitation centrifugal compressor 23 and a flooded evaporator 22 are arranged on the other side of the finned tube heat exchanger. The refrigerant liquid outlet pipe 17 on the finned tube heat exchanger is connected to the magnetic levitation centrifugal compressor 23 and the flooded evaporator 22 respectively. The magnetic levitation centrifugal compressor 23 compresses the low-temperature, low-pressure refrigerant gas into a high-temperature, high-pressure refrigerant gas. The high-temperature, high-pressure refrigerant gas then enters the finned tube heat exchanger for heat exchange, while the refrigerant liquid flowing out from the refrigerant liquid outlet pipe 17 flows to the magnetic levitation centrifugal compressor 23 and the flooded evaporator 22.

[0031] Please see as follows Figure 4 As shown, a chilled water inlet pipe 26 is provided at one end of the flooded evaporator 22 to introduce water that needs to be cooled. After entering the flooded evaporator 22, the water exchanges heat with the low-temperature and low-pressure refrigerant inside. After being cooled down, it flows out from the chilled water outlet pipe 27 to provide chilled water to users. An electronic expansion valve 21 is provided between the refrigerant liquid outlet pipe 17 and the flooded evaporator 22. The electronic expansion valve 21 can control the flow rate and pressure of the refrigerant flowing from the refrigerant liquid outlet pipe 17 to the flooded evaporator 22. The high-temperature and high-pressure refrigerant liquid is throttled and depressurized by the electronic expansion valve 21, becoming a low-temperature and low-pressure gas-liquid two-phase mixture, which enters the flooded evaporator 22 and evaporates and absorbs heat inside the evaporator to cool the chilled water.

[0032] One end of the magnetic levitation centrifugal compressor 23 is connected to the flooded evaporator 22, and the other end is connected to the refrigerant gas inlet pipe 16 on the finned tube heat exchanger, forming a complete refrigerant circulation loop; a hot gas bypass valve 24 is provided on one side of the flooded evaporator 22, and a one-way valve 25 for connection is installed on one side of the refrigerant gas inlet pipe 16, with one end of the one-way valve 25 connected to the magnetic levitation centrifugal compressor 23 and the hot gas bypass valve 24.

[0033] The specific usage and function of this embodiment are as follows: When using the unit, it can achieve three operating modes: no heat recovery, full heat recovery, and partial heat recovery. In the no heat recovery mode, when the user does not use hot water, the variable frequency fan 20 runs at full speed, and the heat from the high-temperature and high-pressure refrigerant exhaust is completely dissipated into the atmosphere through the air-cooled fins 11, meeting the simple cooling needs. In the full heat recovery mode, when the user uses hot water at full load, the variable frequency fan 20 stops running, and the hot water flows through the hot water heat exchange tube 12 to absorb the heat from the refrigerant exhaust, achieving efficient heat recovery to produce hot water. The partial heat recovery mode is suitable for scenarios where the user uses hot water at partial load. The variable frequency fan 20 runs at partial speed, and part of the heat from the refrigerant exhaust is dissipated through the air-cooled fins 11, while the rest is used to heat the hot water. The flexible switching between the three modes can be adjusted according to the user's actual needs and changes in operating conditions, greatly improving the applicability and energy utilization efficiency of the unit, and avoiding the energy loss and system instability problems caused by the frequent switching of condensers under different operating conditions in traditional units.

[0034] The embodiments of this utility model are given for illustration and description purposes only, and are not intended to be exhaustive or to limit the utility model to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the utility model, and to enable those skilled in the art to understand the utility model and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A finned tube heat exchanger, characterized in that: It includes a hot water inlet pipe (15) and a hot water outlet pipe (18), and multiple sets of hot water heat exchange pipes (12) are provided between the hot water inlet pipe (15) and the hot water outlet pipe (18) for communication; Each of the multiple sets of hot water heat exchange tubes (12) is fitted with a refrigerant heat exchange tube (13). One end of each of the multiple sets of refrigerant heat exchange tubes (13) is connected to the refrigerant liquid outlet tube (17) through a first pipe, and the other end of each of the multiple sets of refrigerant heat exchange tubes (13) is connected to the refrigerant gas inlet tube (16) through a second pipe.

2. The finned tube heat exchanger according to claim 1, characterized in that: Multiple sets of refrigerant heat exchange tubes (13) are installed on two sets of heat exchanger end plates (14) at both ends, and multiple sets of air-cooled fins (11) are arranged at equal intervals between the two sets of heat exchanger end plates (14).

3. An air-cooled total heat recovery unit, characterized in that: The finned tube heat exchanger according to any one of claims 1-2 is provided with a variable frequency fan (20) on one side of the finned tube heat exchanger and a magnetic levitation centrifugal compressor (23) and a flooded evaporator (22) on the other side of the finned tube heat exchanger.

4. The air-cooled total heat recovery unit according to claim 3, characterized in that: The refrigerant liquid outlet pipe (17) on the finned tube heat exchanger is connected to the magnetic levitation centrifugal compressor (23) and the electronic expansion valve (21).

5. The air-cooled total heat recovery unit according to claim 4, characterized in that: The flooded evaporator (22) is provided with a chilled water inlet pipe (26) at one end and a chilled water outlet pipe (27) at the other end. An electronic expansion valve (21) is provided between the refrigerant liquid outlet pipe (17) and the flooded evaporator (22).

6. The air-cooled total heat recovery unit according to claim 5, characterized in that: One end of the magnetic levitation centrifugal compressor (23) is connected to the flooded evaporator (22), and the other end is connected to the refrigerant gas inlet pipe (16) on the finned tube heat exchanger.

7. The air-cooled total heat recovery unit according to claim 6, characterized in that: A hot gas bypass valve (24) is provided on one side of the flooded evaporator (22), and a one-way valve (25) for connection is provided on one side of the refrigerant gas inlet pipe (16). One end of the one-way valve (25) is connected to the magnetic levitation centrifugal compressor (23) and the hot gas bypass valve (24).

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