JPS63259363A - Condenser for heat pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to a shell-tube heat pump condenser mainly used in heat pumps that use a non-azeotropic mixed refrigerant that is a mixture of a high-boiling point refrigerant and a low-boiling point refrigerant. Concerning vessels.

(Prior Art) Generally, a single refrigerant (for example, R-12 or R-11) is used as a refrigerant.
As shown in Fig. 4, the heat pump using 4) is composed of a compressor, a condenser 31, an expansion valve 32, an evaporator, etc., and is compressed by a pressing machine 30 to generate high temperature,
The high-pressure refrigerant gas G is transferred to the refrigerant 34 in the α compression mold 31.
After being cooled and liquefied by water (for example, water), the expansion valve 32
It is depressurized and enters the evaporator 33, where it absorbs heat from the outside and evaporates, and is again compressed by the compressor 30, repeating the above-mentioned cycle.

In FIG. 4, 35 is the main body of the condenser 31, 36 is a coolant inlet, 37 is a coolant outlet, 38 is a bay plate, and 39 is a coolant outlet.
is a heat exchanger tube, 40 is a refrigerant inlet, 41 is a refrigerant outlet, 42
is a passage, and 43 is a heat medium.

On the other hand, in recent years, heat pumps that use a non-azeotropic refrigerant mixture of a high boiling point refrigerant (e.g. R-114) and a low boiling point refrigerant (e.g. R-12) have been proposed; It is known that output, withstand voltage, and cycle efficiency can be improved in comparison to

Therefore, if the cycle of a heat pump using a single refrigerant and the cycle of a heat pump using a non-azeotropic mixed refrigerant are represented by TS diagrams (vertical 1 is power versus temperature T1 and 1 is entropy S), The result is as shown in FIG.

That is, the cycle of a heat pump using a single refrigerant is a
b c d, and the heat pump cycle using a non-azeotropic mixed refrigerant is abed, and the evaporation and condensation steps of the latter are the isothermal changes of the former under equal pressure (dotted lines bc, cl
It is inclined as shown by solid lines bc and da with respect to a), and when condensing, the high boiling point refrigerant starts to condense in sequence, and the low boiling point refrigerant finishes condensing in the condensation part of the passage while being cooled by the refrigerant. It is supposed to be done.

On the other hand, if the above process is represented by a temperature composition equilibrium diagram (the vertical axis is the temperature and the hammer axis is the mixing ratio of high boiling point refrigerant and low boiling point refrigerant), the sixth
The result will be as shown in the figure.

Now, if the high boiling point refrigerant is XA% and the low boiling point refrigerant is ) (n%) vapor phase mixed refrigerant (temperature TO1 state ■) is cooled, T.

As the temperature decreases further, the high boiling point refrigerant begins to condense at the point of intersection (■) with the vapor line A, and after passing through the gas-liquid mixed phase state (■), the low boiling point refrigerant begins to condense at the point of intersection (■) with the liquidus line B. finish.

Therefore, the condensation temperature of the mixed refrigerant changes from Tb to Te in FIG. 5 and from T+ to T3 in FIG. By making it a flow, the temperature drop of the coolant in the condenser becomes ef as shown in FIG. 5, and the heat exchange temperature difference can be reduced.

In order to reduce the heat exchange temperature difference, as shown in FIG. It is sufficient to partition with multiple partition plates. Therefore, the refrigerant gas G passes through the passage 42 in a state opposite to the flow of the refrigerant 34 as shown by the dashed line, and the refrigerant liquid condensed in the passage 42 flows through the partition plate material on the bottom side; The water passes through the outlet 45 and sequentially flows toward the outlet 41 side. Incidentally, in FIG. 7, the same members as those shown in FIG. .

That is, in the final process of heating, the low boiling point refrigerant is likely to be liberated in the non-azeotropic mixed refrigerant, which should theoretically become a sulfated mixed condensate (temperature Ts), and the refrigerant gas (temperature T3, state ■) and refrigerant liquid (temperature T). There is a drawback in that the heat transfer surface of the condenser 31 must be increased in order to process this uncondensed gas.

Also, play! The low boiling point refrigerant gas accumulates in the passage 42 and acts like a non-condensable gas, reducing the condensation capacity of the unit 31. In particular, the liquid level of the refrigerant liquid remaining at the bottom of the passage 42 decreases. When the amount of uncondensed gas is high, the amount of uncondensed gas is sucked into the pipe from the outlet 41, and the amount of uncondensed gas remains in the passage 42, and the amount of uncondensed gas becomes even larger.

Further, the refrigerant liquid flows from the inlet cut side to the outlet 41 side through the notch 45 of the partition temporary seal, but due to flow path resistance, the liquid level becomes higher in the passage 42 closer to the inlet cut side, and the refrigerant It will be immersed in liquid. As a result, there is a problem that the heat transfer area decreases and the output decreases.

Incidentally, in order to treat the uncondensed gas, a supercooling heat exchanger 46 may be interposed in the piping of the heat pump as shown in FIG. In this way, the sensible heat of the refrigerant liquid coming out of the condenser 31 is given to the refrigerant gas G at the outlet of the evaporator 33, the refrigerant liquid in the condenser 31 is cooled, and the uncondensed gas in the refrigerant liquid is It will be condensed.

However, in this case, the temperature of the refrigerant gas leaving the evaporator 33 rises, increasing the degree of superheating of the gas in the compressor 30 and increasing the temperature of the discharged gas after compression, which adversely affects the refrigerant and lubricating oil. Undesirable.

(Problems to be Solved by the Invention) The present invention has been devised to solve the above-mentioned problems, and its purpose is to efficiently and reliably condense uncondensed gas and subcool refrigerant liquid. For heat pumps that can improve performance by preventing immersion of heat transfer tubes in refrigerant liquid and retention of uncondensed gas in the (m) path. We provide IFi equipment.

(Means for determining the problem) The condenser for a heat pump of the present invention has a plurality of heat transfer tubes, both ends of which are cooled, in a cylindrical body having 748 inlets and outlets for coolant and 748 inlets and outlets for refrigerant. Inlet/outlet for refrigerant: This is arranged along the axial direction so that the refrigerant gas passes through the passage formed in the main body, and the refrigerant passes through the heat exchanger tube to exchange heat. In the shell tube type decompressor,
The passage is partitioned with several partition plates so that the refrigerant gas passes in a countercurrent flow to the flow of the refrigerant. A liquid storage chamber is formed, and the supercooled liquid storage chamber is divided by a partition wall having a height from the bottom of the main body to the heat transfer tube at the uppermost position and having a small hole in the lower part. It is characterized in that one chamber is connected to the terminal end of the passage via a check valve, and the other chamber is connected to piping leading to the expansion valve.

(Function) The high-temperature, high-pressure refrigerant gas that exits the compressor enters the condenser passage, passes through the passage in a counterflow to the flow of coolant in the heat transfer tubes, and is cooled by the coolant. be condensed.

The refrigerant liquid condensed in the passage and the uncondensed gas that has not been completely condensed flow into the supercooling/liquid storage chamber from the end of the passage.

Note that since the pressure in the passage is higher than the pressure in the subcooling/liquid storage chamber during normal use, the refrigerant liquid in the passage is reliably discharged due to the pressure difference. As a result, the liquid level of the refrigerant liquid in the passage is lowered, so that uncondensed gas in the passage is easily drawn into the supercooling/liquid storage chamber. As a result, it is possible to prevent the heat transfer tubes from being immersed in the refrigerant liquid and to prevent uncondensed gas from remaining in the passages, and there is no reduction in performance.

The refrigerant liquid and uncondensed gas that have flowed into the supercooling/liquid storage chamber are mixed and cooled while passing through the supercooling/liquid storage chamber orthogonally to the heat transfer tubes, and are discharged to the outside. The refrigerant liquid containing uncondensed gas in the supercooling/liquid storage chamber is cooled by the low-temperature refrigerant on the inlet side.Condensation of the uncondensed gas and supercooling of the refrigerant liquid are promoted, increasing the capacity of the condenser. improves.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic system diagram of a heat pump using a condenser according to an embodiment of the present invention, in which 1 is a condenser, 2 is an expansion valve, 3 is an evaporator, and 4 is a compressor.

Note that the heat pump refrigerant is a high boiling point refrigerant (for example, R-1
14) and a low boiling point refrigerant (e.g. R-12) is used, and this non-azeotropic refrigerant mixture is different from a phosphor refrigerant (e.g. R-12 or R-114). During isobaric evaporation and isobaric condensation, the evaporation and condensation temperatures change, and the composition of the refrigerant in the gas phase and liquid phase changes.

The condenser 1 includes a main body 5, a tube plate 6, a heat exchanger tube 7, a passage 8,
The groove is composed of a partition plate 9, a subcooling/liquid storage chamber 10, a watertight partition wall 11, a partition wall 12, a check valve 13, and the like.

That is, the main body 5 includes a body 16 having a refrigerant inlet 14 at the top and a refrigerant outlet 15 at the bottom, and a coolant inlet 17 fixedly attached to one end of the body 16. An inlet side lid part 18 and an outlet 1 for coolant fixedly attached to the other end of the body part 16.
9 and an outlet side lid part 20.

The tube plate 6 is interposed between the body portion 16 of the main body 5 and each lid portion 18, 20 so as to disconnect the refrigerant inlet/outlet 15, 14 and the coolant inlet/outlet 19,17. ing.

As a result, a passage 8 for refrigerant passage is formed within the body 16.

The heat exchanger tube 7 is supported through the tube plate 6, and is supported by the main body 5.
A plurality of them are arranged along the axial direction within the shaft. or,
Openings at both ends of each heat transfer tube 7 form a coolant inlet 14 of the main body 5.
and the outlet 15. The passage 8 has a plurality of partitions so that the refrigerant gas G passes through the passage 8 in a counterflow to the flow of the coolant 21 in the heat transfer tubes 7. It is partitioned by a board 9. In this embodiment, the partition plates 9 are arranged alternately at the top and bottom of the old capital 16 in the longitudinal direction of the body 16, and the partition plates 9 on the bottom side have cutouts 22 for passage of refrigerant liquid. is formed.

The supercooling/liquid storage chamber 10 is formed at the end of the passage 8, and is divided into a first subcooling/liquid storage chamber 10a and a second supercooling/liquid storage chamber tob.

That is, in this embodiment, the supercooling/liquid storage chamber 10 is connected to the passage 8.
It is formed by disposing a watertight partition wall 11 in close contact with the inner circumferential wall of the body part 16 at the terminal end of the body part 16. The heat tube 7 is divided into two by a partition wall 12 provided along the axis thereof into a first subcooling/liquid storage chamber tOa and a second subcooling/liquid storage chamber 10b. 5 has a height from the bottom to the heat transfer tube 7 in the uppermost direction, and has a small hole 23 at the bottom.
is drilled. Also, the first supercooling/liquid storage chamber 10a
The bottom of the second supercooling/liquid storage chamber TOB is connected to the expansion valve 2 by a pipe 26, and the bottom of the second supercooling/liquid storage chamber TOB is connected to the expansion valve 2 by a pipe 25 with a valve 24 and a check valve 13 interposed therebetween. ing.

The refrigerant gas G, which has become high temperature and high pressure after being compressed by the compressor 3 storage unit 4, enters the passage 8 of the condenser 1 from the refrigerant inlet 14, and passes through the passage 8 inside the heat transfer tube 7. It passes in a counterflow to the flow of the coolant 21, is cooled by the coolant 21, and is condensed.

The refrigerant liquid condensed in the passage 8 and the uncondensed gas that has not been completely condensed flow from the refrigerant outlet 15 through II M 25 and the inlet 27 into the first supercooling/liquid storage chamber 10a. Note that the pressure inside the passage 8 is the same as that of the supercooling/liquid storage chamber 1 during normal use.
Since the pressure is higher than 0, the cold lyophilic liquid at the bottom of the passage 8 is smoothly and reliably discharged to the first supercooling/liquid storage chamber 10a side due to the pressure difference. In addition, since the check valve 13 is interposed in the lk pipe 25, the passage 8 is
This prevents the refrigerant liquid from flowing back into the tank. As a result, not much refrigerant liquid accumulates at the bottom of the passage 8, and the liquid level of the refrigerant liquid becomes low, so that the heat transfer tubes 7 are not immersed in the refrigerant liquid.
Capability can be prevented from decreasing. However, when the liquid level of the refrigerant liquid becomes low, the uncondensed gas in the passage 8 is also easily drawn into the pipe 25, and the amount of uncondensed gas retained in the passage 8 decreases, making condensation more active.

The refrigerant liquid and the uncondensed gas that have flowed into the lower part of the first supercooling/liquid storage chamber 10a flow upward perpendicularly to the heat transfer tubes 7 while being mixed and cooled, overflow the partition wall 12, and flow into the second subcooling/liquid storage chamber 10a. The liquid enters the supercooling/liquid storage chamber TOB, flows downward therefrom, and reaches the expansion valve 2 via the outlet 28 and the piping 26. Note that the refrigerant liquid containing uncondensed gas in the supercooled liquid storage chamber 10 is cooled by the low-temperature coolant 21 on the inlet 17 side, so that condensation of the uncondensed gas and supercooling of the refrigerant liquid are promoted. is,
The capacity of the condenser is improved. Also, a part of the refrigerant liquid containing uncondensed gas bypasses the small holes 23 of the partition wall 12;
Since most of the refrigerant liquid flows as described above, the overall flow is not obstructed. Furthermore, in the supercooling/liquid storage chamber 10, during standard operation, the top of the partition wall 12 becomes the liquid level, and when the refrigerant liquid increases due to a load change, the gas phase portion of the supercooling/liquid storage chamber 10 is compressed. has a liquid storage effect, and when the refrigerant liquid decreases, the second supercooling and liquid storage chamber 10
Although the liquid level is lower than b, the refrigerant liquid flows from the first supercooling/liquid storage chamber 10a to the second supercooling/liquid storage chamber 10b through the small hole 23 of the partition wall 12, and both are the same. It becomes liquid level.

Incidentally, the supercooling/liquid storage chamber 10 serves both supercooling and liquid storage functions. In addition, the volume of the supercooling/liquid storage chamber 10 is determined by the size of the supercooling cooling surface, so if the storage capacity of the refrigerant liquid is insufficient, the liquid storage chamber 10 is installed at 11 Jin 26143.
9 may be interposed.

(Effects of the invention) As mentioned above, the heat pump device of the present invention is
Separate the end of the passage through which the refrigerant gas passes with a watertight partition wall 2
to form a supercooling/liquid storage chamber, and dividing the supercooling/liquid storage chamber into two with a partition wall, one chamber is connected to the end of the passage, and the other chamber is connected to the F1 pipe leading to the expansion valve. Because it is configured to connect,
The refrigerant liquid and uncondensed gas in the passage are once introduced into the supercooling/liquid storage chamber and mixed, where they are cooled with low-temperature refrigerant.

As a result, the condensation of uncondensed gas and the supercooling of the refrigerant liquid are promoted, resulting in good and reliable condensation. The refrigerant gas can be mixed and cooled with a supercooled high-boiling refrigerant liquid to be condensed.

Furthermore, since a subcooling/liquid storage chamber is formed and the refrigerant liquid is allowed to flow into this chamber, the refrigerant liquid does not accumulate much in the passage. As a result, the liquid level of the refrigerant liquid in the passage does not become low and the heat transfer tubes are not immersed in the refrigerant liquid, thereby preventing a decrease in performance. However, when the liquid level of the refrigerant becomes low, uncondensed gas in the passage is easily sucked into the supercooling/liquid storage chamber, and the retention of uncondensed and trapped gas in the passage decreases, resulting in active condensation. Become.

Furthermore, since the refrigerant liquid in the supercooling/liquid storage chamber is cooled with refrigerant, the amount of water from the compressor is reduced compared to the conventional case where the refrigerant liquid from the condenser is cooled with refrigerant gas from the purple generator. The discharge gas can be kept at a low temperature, and there will be no adverse effects due to high temperatures of the refrigerant or lubricating oil.

In addition, since a supercooling/liquid storage chamber for supercooling is provided inside the condenser, the groove construction and piping of the equipment itself are easier than when using a conventional heat exchanger for supercooling. This makes maintenance easier.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram of a heat pump using a condenser according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■ in Fig. Figure 4 is a schematic system diagram of a heat pump using a single refrigerant and a conventional concentrated/condensing type, and Figure 5 shows a heat pump cycle using a single refrigerant and a heat pump using a non-azeotropic mixed refrigerant. T559 diagram of the cycle, FIG. 6 is a two-gland diagram of temperature composition equilibrium in a non-azeotropic mixed refrigerant, and FIG. 7 is a schematic system diagram of a heat pump using a non-azeotropic mixed refrigerant and a conventional condenser. 1 is a condenser, 2 is an expansion valve, 5 is a main body, 7 is a heat exchanger tube, 8 is a passage, 9 is a partition plate, 10 is a subcooling/liquid storage chamber, 11 is a watertight partition wall, 12 is a sinking wall, 13 is a check valve, 14 is a refrigerant inlet, 15 is a refrigerant outlet, 17 is a coolant inlet,
19 is a coolant outlet, 21 is a coolant, 26 is a pipe, G
is a refrigerant gas.

Claims (1)

[Claims] In a cylindrical body (5) with inlets and outlets (19), (17) for coolant and inlets and outlets (15), (14) for refrigerant,
A plurality of heat transfer tubes (7) are connected at both ends to coolant inlets and outlets (1).
9), disposed along the axial direction to communicate with (17),
The passage (8) formed in the main body (5) is filled with refrigerant gas (G).
However, in a shell tube type condenser in which the refrigerant (21) passes through the heat transfer tube (7) to perform heat exchange, the refrigerant gas (G) cools the passage (8). agent (21)
The passageway (8) is partitioned with a plurality of partition plates (9) so that the flow passes as a counterflow, and the terminal end of the passageway (8) is hermetically partitioned with a watertight partition wall (11) to serve as a supercooling and liquid storage area. Room (10)
The supercooling/liquid storage chamber (10) is formed into a main body (5).
) The partition wall (12) has a height from the bottom to the heat transfer tube (7) at the uppermost position, and is divided into two by a partition wall (12) with a small hole (23) in the lower part, and one chamber is equipped with a check valve (13). ) through passage (8)
and the other chamber to the expansion valve (2).
26) A condenser for a heat pump, characterized in that it is connected to a condenser.