TWI789604B - Condenser and Condenser Efficiency Improvement Method - Google Patents

Abstract

The invention relates to a condenser and a method for increasing the efficiency of the condenser. The method for improving the efficiency of the condenser of the invention is as follows: the high-pressure, high-temperature superheated gaseous refrigerant from the compressor is introduced into the liquid refrigerant area inside the condenser, and the high-pressure, high-temperature superheated gaseous refrigerant and the condenser The internal liquid refrigerant will produce heat transfer, which will cause the high-pressure, high-temperature superheated gas refrigerant to cool down and condense, and the liquid refrigerant inside the condenser will heat up and gasify due to heat absorption, achieving the effect of improving the efficiency of the condenser.

Description

Condenser and Condenser Efficiency Improvement Method

The invention belongs to the technical field of refrigeration and air conditioning, in particular to a condenser and a method for improving the efficiency of the condenser, which has the effect of improving the efficiency of the condenser.

The four major components of refrigeration and air conditioning are compressor, condenser, expansion valve and evaporator in sequence. The compressor sucks the lower-pressure gaseous refrigerant from the evaporator, raises its pressure, and sends it to the condenser, where it is condensed into a higher-pressure liquid refrigerant, and then becomes a lower-pressure liquid refrigerant through the expansion valve. , into the evaporator, where it absorbs heat and evaporates to become a gaseous refrigerant with a lower pressure, and then completes a complete refrigeration and air conditioning cycle. Please refer to Figure 1 for the conventional condenser heat exchange diagram, Figure 2 for the conventional condenser refrigerant pressure-enthalpy diagram and Figure 3 for the conventional condenser heat exchange temperature position diagram. It can be seen from the figure that the general condenser 1 has a liquid-gas two-phase refrigerant coexistence area inside, that is, the gaseous refrigerant area 10 is generally located above, and the liquid refrigerant area 11 is located below. The conventional condenser 1 comes from the compression The high-pressure, high-temperature superheated gaseous refrigerant 13 of the machine 12 enters from the gaseous refrigerant area 10 of the condenser 1 [that is, the top or side of the condenser 1 enters the condenser 1, and the top is shown in Fig. 1 ], and the relatively low-temperature cooling fluid 14 condenses into liquid refrigerant 15 in the liquid refrigerant zone 11 below after the heat exchange, and the liquid refrigerant 15 is output to the expansion valve 16 again. In the conventional condenser 1, since the high-pressure, high-temperature superheated gaseous refrigerant 13 of the compressor 12 enters from the gaseous refrigerant area 10 of the condenser 1, it condenses from a gaseous state to a liquid state after heat exchange. Difficulties to be overcome.

The refrigerating cycle formula explanation of aforementioned conventional condenser: (referring to the conventional condenser of Fig. 2 Refrigerant pressure enthalpy diagram)

1. Compression process a-b (compressor)

W _c = G ×( h _b - h _a )

2. Condensation process b-c (condenser)

Q _c = G ×( h _b - h _c )

3. Throttling process c-d (expansion valve)

h _d = h _c

4. Evaporation process d-a (evaporator)

Q _e = G ×( h _a - h _d )

5. The operation balance of the compressor

Q _c = Q _e + W _c

in:

W _c = compressor power KJ/S(KW)

G=refrigerant mass flow rate KG/S

h=refrigerant enthalpy KJ/KG

Q _c = heat dissipation per unit time of condenser KJ/S(KW)

Q _e = heat absorption per unit time of the evaporator KJ/S (KW)

The heat transfer equation of the aforementioned conventional condenser

Q _c =UA(LMTD)

LMTD=(ΔT _A -ΔT _B )/ln(ΔT _A /ΔT _B )

ΔT _A =T _c -T _A

ΔT _B =T _c -T _B

in:

Q _c = heat dissipation per unit time of condenser KJ/S(KW)

U=total heat transfer coefficient KW/M ² . ℃

A = heat transfer surface area M ²

LMTD = logarithmic mean temperature difference of the condenser °C

T _C = the condensation temperature of the refrigerant in the two-phase region °C

T _A = temperature of the cooling fluid at A in °C

T _B = temperature of the cooling fluid at B °C

ΔT _A = the temperature difference between the two fluids at A, °C

ΔT _B = the temperature difference between the two fluids at B

Furthermore, please refer to the schematic diagram of the conventional refrigerating and air-conditioning circulation system in FIG. 4 and the pressure-enthalpy diagram of the refrigerant in the conventional refrigerating and air-conditioning circulation system in FIG. 5. In some heat recovery applications, two condensers are used, and the first condenser 23 It is connected in series or in parallel with the second condenser 24. The existing control technology is to use a proportional three-way valve 2 to control the distribution of hot gas from the outlet of the compressor 20 to the first condenser 23 and the second condenser 24. However, the pressure drop of this type is very large, and the proportional three-way valve is a custom-made product, which is difficult and expensive to obtain, resulting in the lack of popularization in use. How to reduce the pressure drop and make the system more stable is a difficult problem to be overcome in the industry.

In view of the deficiency of the above-mentioned conventional technology, the inventor of this case has accumulated professional knowledge such as the design and construction of air-conditioning products for many years. After continuous research and improvement, the present invention has been successfully developed and released to the world.

The reason is that the main purpose of the present invention is to provide a method for improving the efficiency of the condenser, The system introduces the high-pressure, high-temperature superheated gaseous refrigerant from the compressor into the liquid refrigerant area inside the condenser. The high-pressure, high-temperature superheated gaseous refrigerant and the liquid refrigerant inside the condenser will produce heat transfer, which will cause the high-pressure, high-temperature superheated gaseous refrigerant to produce cooling and condensation, and condensation The liquid refrigerant inside the condenser is heated and vaporized due to heat absorption, which improves the efficiency of the condenser.

The aforementioned condenser efficiency improvement method of the present invention also includes a method of increasing the contact area of the high-pressure, high-temperature superheated gaseous refrigerant introduced into the liquid refrigerant area inside the condenser, so that the high-pressure, high-temperature superheated gaseous refrigerant and the liquid refrigerant have more contact areas to increase heat transfer Effect.

Another main purpose of the present invention is to provide a condenser. The condenser has a gaseous refrigerant area and a liquid refrigerant area, and a heat exchange channel for low-temperature fluid circulation, and has a refrigerant inlet to introduce high-pressure, high-temperature superheated gaseous refrigerant into the compressor. , and a refrigerant outlet to output the liquid refrigerant to the expansion valve, characterized in that: the refrigerant inlet leading to the high-pressure, high-temperature superheated gas refrigerant of the compressor is located in the liquid refrigerant area inside the condenser, so as to achieve the effect of improving the efficiency of the condenser.

The aforementioned condenser of the present invention further includes an aeration device, which is arranged at the refrigerant inlet end inside the condenser, and is connected to the high-pressure, high-temperature superheated gaseous refrigerant introduced into the compressor, so that the high-pressure, high-temperature superheated gaseous refrigerant and the liquid refrigerant have more Contact area to increase heat conduction effect.

The aforementioned aeration device of the present invention is made of porous material.

The aforementioned aeration device of the present invention is a tubular body or a plate-shaped body with mesh pores.

The aforesaid condenser of the present invention further includes a partition, which is arranged in the liquid refrigerant area inside the condenser to separate the liquid refrigerant into a high-temperature stirred area and a low-temperature un-stirred area, so as to ensure that the liquid refrigerant can be subcooled at a better temperature. out of the condenser.

Another main purpose of the present invention is to provide a condenser for heat recovery, which mainly includes two first condensers and second condensers connected in series or in parallel, and the second condensers are sequentially Connect the expansion valve, evaporator, compressor and the first condenser to form a complete cycle, which is characterized in that a 100% system capacity solenoid valve is installed in series between the first condenser and the second condenser, and another solenoid valve is installed in the first condenser Install 1-3 bypass solenoid valves in parallel with a total capacity equal to 100% of the system capacity. Multiple sets of solenoid valves are connected in parallel to reduce pressure drop flexibly, and have the effect of improving condenser efficiency and market popularization.

CON1: 1st condenser

CON2: 2nd condenser

SV1: Solenoid valve

SV2: Solenoid valve

SV3: Solenoid valve

SV4: Solenoid valve

1: condenser

10: Gaseous refrigerant area

11: Liquid refrigerant area

12: Compressor

13: High pressure and high temperature superheated gaseous refrigerant

14: cooling fluid

15: liquid refrigerant

16: Expansion valve

2: Proportional three-way valve

20: Compressor

21: Expansion valve

22: Evaporator

23: 1st condenser

24: The second condenser

3: Condenser

30: Gaseous refrigerant area

31: Liquid refrigerant area

32: cooling fluid

320: Coolant inlet

321: Coolant outlet

322: cooling air inlet

323: cooling air outlet

33: Refrigerant inlet

34: High pressure and high temperature superheated gaseous refrigerant

35: Refrigerant export

36: Expansion valve

37: Aeration device

38: Partition

310: high temperature agitation zone

311: low temperature unstirred zone

40: Expansion valve

41: Evaporator

42:Compressor

〔Figure 1〕is a schematic diagram of the heat exchange of a conventional condenser;

[Fig. 2] is the pressure-enthalpy diagram of the conventional condenser refrigerant;

[Figure 3] is a conventional condenser heat exchange temperature position diagram;

[Figure 4] is a schematic diagram of a conventional refrigeration and air-conditioning circulation system;

[Figure 5] is the pressure-enthalpy diagram of the refrigerant in the conventional refrigeration and air-conditioning circulation system;

[Fig. 6] is the pressure-enthalpy diagram of the condenser refrigerant of the present invention;

[Fig. 7] is the heat exchange temperature position map of the condenser of the present invention;

[Fig. 8] is a schematic diagram of the heat exchange of the condenser of the present invention;

[Fig. 9] is a schematic diagram of the heat exchange of the water-cooled shell-and-tube condenser of the present invention;

[Fig. 10] is a schematic diagram of the heat exchange of the air-cooled tube-fin condenser of the present invention;

[Fig. 11] is a schematic diagram of the heat exchange of the condenser of the aeration device of the present invention;

[Fig. 12] is a schematic diagram of the heat exchange of the clapboard condenser of the present invention;

[Fig. 13] is a schematic diagram of the refrigerating and air-conditioning circulation system of the present invention;

[Fig. 14] is the refrigerant pressure-enthalpy diagram of the refrigerating and air-conditioning circulation system of the present invention.

The invention belongs to the technical field of refrigeration and air conditioning, in particular to a condenser and a condenser The efficiency-enhancing method has the effect of increasing the efficiency of the condenser. The condenser described in the description of the present invention is a general term, and its principle is applicable to condensers of various systems, for example, air-cooled, water-cooled, multi-tube condensers, tube-fin condensers, shell-and-tube condensers...etc. Most of the double condenser systems are heat recovery systems, such as heat pump systems, which can be subdivided into water-to-air, gas-to-gas, and water-to-water heat pumps.

The method for improving the efficiency of the condenser of the present invention is to introduce the high-pressure, high-temperature superheated gaseous refrigerant from the compressor into the liquid refrigerant area inside the condenser, and the high-pressure, high-temperature superheated gaseous refrigerant and the liquid refrigerant inside the condenser will produce heat transfer, so that the high-pressure, high-temperature superheated gaseous The refrigerant produces cooling and condensation, and the liquid refrigerant inside the condenser causes heating and gasification due to heat absorption. Due to the buoyancy of the high-temperature gas refrigerant, it will float upwards, and it is not easy to be directly output from the outlet of the liquid refrigerant in a short cycle, so it can achieve enhanced condensation. device efficiency.

There are four benefits obtained by the aforementioned method of the present invention. Please refer to the pressure enthalpy diagram of the refrigerant in the condenser of the present invention in FIG. 6 and the heat exchange temperature position diagram of the condenser in the present invention in FIG. 7 . The first point is that the high-pressure, high-temperature superheated gaseous refrigerant is mixed with the liquid refrigerant inside the relatively low-temperature condenser, and the high-pressure, high-temperature superheated gaseous refrigerant is condensed rapidly. As shown in Figure 6, the state of the compressor outlet is improved from point b to point b', because part The liquid refrigerant inside the condenser is heated by the high-pressure, high-temperature superheated gas refrigerant to become a gas refrigerant. The pressure and temperature rise, but the discharge port does not rise. Theoretically, point b and point b' should be on the isotherm line, and the compression work (Wc') decreases. , which can improve the isentropic efficiency of the compressor. The second point is that part of the liquid refrigerant inside the condenser produces an evaporation effect and becomes a gaseous refrigerant with a larger specific volume, which increases the pressure of the condenser. Because of the two-phase coexistence area, the average condensation temperature will also rise, and the logarithmic average temperature of the condenser will be increased. Poor results in better heat transfer efficiency. The third point is that the high-pressure, high-temperature superheated gaseous refrigerant will form bubbles in the liquid refrigerant inside the condenser, and float upward due to buoyancy, producing a stirring effect and forming better heat transfer performance. The fourth point, the heat transfer Qc of the condenser increases, and the heat transfer Qe=Qc-Wc of the evaporator also Increase, the coefficient of performance COP of the system increases, so as to achieve the aforementioned effect of improving the efficiency of the condenser.

The refrigerating cycle formula explanation of condenser of the present invention: (please refer to Fig. 6)

1. Compression process a-b' (compressor)

W _{c '} = G ×( h _{b '} - h _a )

2. Condensation process b'-c' (condenser)

Q _{c '} = G ×( h _{b '} - h _{c '} )

3. Throttling process c’-d’ (expansion valve)

h _{d '} = h _{c '}

4. Evaporation process d’-a (evaporator)

Q _{e '} = G ×( h _a - h _{d '} )

5. The operation balance of the compressor

Q _{c '} = Q _{e '} + W _{c '}

in:

W _{c '} = compressor power KJ/S(KW)

G=refrigerant mass flow rate KG/S

h=refrigerant enthalpy KJ/KG

Q _{c '} = heat dissipation per unit time of condenser KJ/S(KW)

Q _{e '} = heat absorption per unit time of evaporator KJ/S(KW)

The heat transfer equation of condenser of the present invention

Q _{c '} =UA(LMTD)

LMTD=(ΔT _A -ΔT _B )/ln(ΔT _A /ΔT _B )

ΔT _A =T _{c '} -T _A

ΔT _B =T _{c '} -T _B

in:

Q _{c '} = heat dissipation per unit time of condenser KJ/S(KW)

U=total heat transfer coefficient KW/M ² . ℃

A = heat transfer surface area M ²

LMTD = logarithmic mean temperature difference of the condenser °C

T _C' = condensing temperature of the refrigerant in the two-phase region °C

T _A = temperature of the cooling fluid at A in °C

T _B = temperature of the cooling fluid at B °C

Δt _A = the temperature difference between the two fluids at A, °C

Δt _B = the temperature difference between the two fluids at B, °C

Taking the water-cooled condenser as an example (as shown in Figure 9, the heat exchange diagram of the water-cooled shell-and-tube condenser of the present invention), it is assumed that the condensation temperature of the refrigerant is 42°C, the inlet water temperature of the cooling water is 32°C, and the outlet water temperature of the cooling water is 37°C , as the following table: the present invention water-cooled condenser condensation temperature and LMTD relationship calculation table, when the condensation temperature increases upwards, the logarithmic mean temperature difference LMTD of the condenser also increases upwards, which will increase the heat dissipation of the condenser.

Taking an air-cooled condenser as an example (as shown in Figure 10 the heat exchange diagram of the air-cooled tube-fin condenser of the present invention), assuming that the condensation temperature of the refrigerant is 50°C, the inlet water temperature of the cooling water is 35°C, and the outlet water temperature of the cooling water is 40°C, as shown in the following table: the calculation table of the relationship between the condensing temperature and LMTD of the air-cooled condenser of the present invention. When the condensing temperature increases upwards, the logarithmic mean temperature difference LMTD of the condenser also increases upwards, which will increase the heat dissipation of the condenser.

The aforementioned condenser efficiency improvement method of the present invention also includes a method of increasing the contact area of the high-pressure, high-temperature superheated gaseous refrigerant introduced into the liquid refrigerant area inside the condenser, so that the high-pressure, high-temperature superheated gaseous refrigerant can form more bubbles (such as setting an aeration device) , so that the high-pressure, high-temperature superheated gaseous refrigerant and the liquid refrigerant have more contact areas to increase the heat conduction effect, and the smaller the bubbles, the better the heat conduction effect.

Please refer to the heat exchange schematic diagram of the condenser of the present invention shown in Fig. 8, the heat exchange schematic diagram of the water-cooled shell-and-tube condenser of the present invention shown in Fig. 9, and the heat exchange schematic diagram of the air-cooled tube-fin condenser of the present invention shown in Fig. 10, as can be seen from the figures. The device 3 has a gaseous refrigerant area 30 and a liquid refrigerant area 31 inside, and a heat exchange channel for the circulation of the cooling fluid 32 [shown in Figure 9 as a water-cooled type, which has a cooling liquid inlet 320 and a cooling liquid outlet 321; shown in Figure 10 Shown as an air-cooled type, it has a cooling air inlet 322 and a cooling air outlet 323], and also has a refrigerant inlet 33 to introduce the high-pressure, high-temperature superheated gaseous refrigerant 34 of the compressor, and a refrigerant outlet 35 to output the liquid refrigerant to the expansion valve 36, It is characterized in that: the refrigerant inlet 33 leading to the high-pressure, high-temperature superheated gaseous refrigerant 34 of the compressor is located in the liquid refrigerant area 31 inside the condenser 3, and the high-pressure, high-temperature superheated gaseous refrigerant 34 and the liquid refrigerant inside the condenser 3 will produce heat transfer, so that The high-pressure, high-temperature superheated gaseous refrigerant 34 produces cooling and condensation, while the liquid refrigerant inside the condenser 3 heats up and gasifies due to heat absorption. Due to the buoyancy of the high-temperature gaseous refrigerant, it will float upwards, and it is not easy to short cycle directly from the liquid refrigerant outlet 35 output, so as to achieve the effect of improving the efficiency of the condenser.

Please refer to Fig. 11, the aforesaid condenser 3 of the present invention further includes an aeration device 37, the aeration device 37 is located at the end of the refrigerant inlet 33 inside the condenser, and is connected to the high-pressure, high-temperature superheated gaseous refrigerant 34 introduced into the compressor. The high-temperature superheated gaseous refrigerant 34 uses the aeration device 37 to form more bubbles, so that the high-pressure, high-temperature superheated gaseous refrigerant 34 has more contact area with the liquid refrigerant to increase the heat conduction effect, and the smaller the bubbles, the better the heat conduction effect.

The aforementioned aeration device 37 of the present invention is made of porous material.

The aforementioned aeration device 37 of the present invention is a tubular body or a plate-shaped body with mesh pores.

Please refer to Fig. 12, the aforementioned condenser 3 of the present invention further includes a partition 38, which is arranged in the liquid refrigerant region 31 inside the condenser to separate the liquid refrigerant region 31 into a high-temperature stirring region 310 and a low-temperature non-stirring region 311, although the high-pressure, high-temperature superheated gaseous refrigerant 34 floats up due to buoyancy, it will not It flows to the refrigerant outlet 35, and the separator is set in the liquid refrigerant region 31 inside the condenser to separate the liquid refrigerant region 31 into a high-temperature stirred region 310 and a low-temperature un-stirred region 311, which can ensure that the refrigerant can be cooled after better supercooling. out of condenser 3.

Please refer to Fig. 13 for the schematic diagram of the refrigerating and air-conditioning circulation system of the present invention and Fig. 14 for the refrigerant pressure-enthalpy diagram of the refrigerating and air-conditioning circulation system of the present invention. This embodiment is applied to heat recovery and mainly includes two series or parallel first Condenser CON1 and the second condenser CON2, the second condenser CON2 is sequentially connected to the expansion valve 40, the evaporator 41, the compressor 42 and the first condenser CON1 to form a complete cycle, which is characterized in that: the first condenser CON1 and the second A solenoid valve SV1 with 100% system capacity is installed in series between the 2 condensers CON2, and 1-3 bypass solenoid valves SV2 with a total capacity equal to 100% system capacity are installed in parallel at the first condenser CON1 [in In this embodiment, there are three bypass solenoid valves SV2, SV3, and SV4 whose total capacity is equal to 100% of the system capacity; in actual implementation, one bypass solenoid valve SV2 can be set, which is equal to 100% of the system capacity; or The total capacity of 2 bypass solenoid valves SV2, SV3 can be set equal to 100% of the system capacity, and the total capacity of 3 bypass solenoid valves SV2, SV3, SV4 can also be set equal to 100% of the system capacity]. A solenoid valve can achieve the same effect, but the pressure drop is lower, and the system is more stable. Because the condensation process is theoretically an equal-pressure process, and because multiple sets of solenoid valves are used in parallel, the design for reducing the pressure drop will be more flexible. The pressure-enthalpy diagram is shown in Figure 14, and the outlet state of the compressor 42 is improved from point b To point b', because theoretically point b' is lower than point b, the compression work (Wc') is reduced, and the efficiency can be improved. The parallel design of multiple solenoid valves is more flexible than the control of traditional proportional three-way valves. In terms of market applications, solenoid valves are mass-produced stock items, which are easy to obtain (as mentioned above: the proportional three-way valve used by the practitioner is a custom-made product, which is difficult and expensive to obtain).

In summary, a "condenser and condenser efficiency improvement" disclosed by the present invention The "method" has never been seen in the past, nor has it been seen in domestic and foreign publications. It already has the patent requirements of novelty, and this invention can clearly eliminate the lack of conventional technology and achieve the design purpose. It also fully meets the patent requirements. I would like to ask your examiner to review the application according to the law and grant a patent for this case. I really appreciate the convenience.

However, the above-mentioned ones are only preferred embodiments of the present invention, and are not intended to limit the scope of this creation. For those who are familiar with this art, they can use the description of the present invention and the alternative methods made by the scope of the patent application and so on. Effective structural changes should be included in the patent scope of the present invention.

3: Condenser

30: Gaseous refrigerant area

31: Liquid refrigerant area

32: cooling fluid

33: Refrigerant inlet

34: High pressure and high temperature superheated gaseous refrigerant

35: Refrigerant export

36: Expansion valve

Claims (5)

A condenser, the condenser has a gaseous refrigerant area and a liquid refrigerant area, and a heat exchange channel for the cooling fluid to circulate, and also has a refrigerant inlet to import the high-pressure, high-temperature superheated gaseous refrigerant of the compressor, and a refrigerant outlet to output the liquid refrigerant In the expansion valve, it is characterized in that: the refrigerant inlet for introducing the high-pressure, high-temperature superheated gaseous refrigerant into the compressor is located below the liquid level of the saturated liquid refrigerant in the liquid refrigerant area inside the condenser, and the high-pressure, high-temperature superheated gaseous refrigerant comes from the liquid refrigerant in the condenser The saturated liquid refrigerant that can form bubbles in the area is introduced below the liquid surface. The introduced high-pressure, high-temperature superheated gas refrigerant will form bubbles in the saturated liquid refrigerant in the liquid refrigerant area inside the condenser, and float upward due to buoyancy. The saturated liquid refrigerant in the condenser produces agitation and heat transfer, which causes the high-pressure, high-temperature superheated gas refrigerant to cool down and condense, while the saturated liquid refrigerant in the liquid refrigerant area inside the condenser increases in temperature due to heat absorption and gasification. Heat conduction performance, in order to achieve the effect of improving the efficiency of the condenser. The condenser as described in Claim 1 further includes an aeration device, which is installed at the refrigerant inlet end inside the condenser and connected to the high-pressure, high-temperature superheated gaseous refrigerant introduced into the compressor. The gas device forms more bubbles, so that the high-pressure, high-temperature superheated gas refrigerant and the saturated liquid refrigerant have more contact areas to increase the heat transfer effect. The condenser as claimed in claim 2, wherein the aeration device is made of porous material. The condenser according to claim 2, wherein the aeration device is a tubular body or a plate-shaped body with mesh pores. The condenser as described in claim 1 further includes a partition, which is arranged in the liquid refrigerant area inside the condenser to separate the liquid refrigerant into a high-temperature stirred area and a low-temperature un-stirred area to ensure that the saturated liquid refrigerant can It exits the condenser after optimal subcooling.

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