JPS60108652A - 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 The present invention is an improvement of a 14-energy type heat bonzo equipped with a plurality of condensers having different pressures and a multistage or plurality of compressors that send corresponding compressed gas to each of these condensers. Regarding. In addition, in this F3A specification, "heat pump" refers not only to a heat pump in a narrow sense that produces hot fluid, but also to a heat pump in a broad sense that includes refrigeration that produces cold fluid.

Recently, heat pumps that completely cure condensers have been attracting attention from an energy-saving perspective.

First, this heat pump will be explained using sheet 70 in FIG.

The liquid refrigerant in the evaporator is heated and evaporated by the heat source water fed through the pipe, and is sucked into the first stage compressor through the suction pipe 3. A small amount of the gas compressed by the compressor is discharged to the condenser B via the discharge pipe, and the remaining 2/3 is passed through the branch pipe 7 to the λ stage compressor. It gets sucked into machine r. Similarly, λ stage compressor ♂
For example, about //2 of the discharged gas is sent to the condenser via the discharge pipe /7, and the remaining //2 is sent to the suction part of the third stage compressor /Q, where it is compressed and sent to the condenser /l. is discharged.

Cooling of each of the condensers described above is performed by a load fluid as a fluid to be heated, and the load fluid is Bonzo/,
2, these three condensers Z.

It is heated to a jul which passes // in series to one cabinet.

In this system having multiple condensers with different pressures, a load fluid with a large inlet/outlet temperature is usually applied. It is heated by 70° C. in the condensers g, ri, and //, and the temperature becomes about 2θ° C. at the load fluid outlet and is used for loading.

On the other hand, the refrigerant gas condenses in the condenser
! It is depressurized by the depressurizer/2 and sent to the next stage condenser. At this time, Franche gas is generated due to the pressure reduction, but this gas is cooled by the load fluid in this condenser together with the refrigerant gas discharged from the second stage compressor through the discharge pipe 77'f. be condensed. Next, the pressure is reduced by the pressure reducing device 1 through the pipe 7g and sent to the lowest stage condenser B, and the flash gas is sent to the discharge pipe 3'! i-
After that, it is condensed and liquefied together with the refrigerant gas discharged from the first stage compressor. Then, the pressure is reduced by the lowest stage pressure reducing device 20, and the air is transferred to the evaporator/cooler 3.

In the above device (heat pump), the inlet and outlet portions of the load fluid are large, so the condensation temperatures of the three condensers are significantly different. For example, 2, each of the above condensers//, 2, ◇ decomposition temperature/false, respectively j'Q, 13
°C, 7. Assuming f°C and assuming that the evaporation temperature in the evaporator is θ°C, gi! The pressure to be increased in the /stage compressor is 7j℃ equivalent pressure from the SO"C phase pressure, so the equivalent pressure temperature difference is 2!℃. Similarly, the second and third stage compression The phase pressure temperature difference is 70°C in both the 7th stage and λ stage compressors.In other words, this system has a condensing temperature equivalent to 75°C and rr°C below the load fluid temperature of 75°C and rr°C, respectively, in the 7th stage and λ stage compressors. All the refrigerant gas discharged from the last stage of the multi-stage compressor is led to one condenser, and the load fluid temperature is increased from, for example, the inlet temperature to °C to the outlet temperature of o''C. This has the advantage that less power is required than in the conventional system in which the compressor is operated, and the required pressure A+1d ratio of one compressor is significantly smaller than that in the case of seven compressors.

However, this heat pump has two major drawbacks as follows. One of them is to approach the lowest stage where the pressure is lower like the 2nd stage and the 1st stage, and the flow of refrigerant liquid in the iL and small vessel. This means that the flow will become a pillar. In the above example, the main refrigerant flows into the lower stage condenser 6 of the special vc% from the pressure reducing device, so a space is required at the bottom of the condenser for this liquid refrigerant to flow. . When using a mixed refrigerant as shown below, the condenser becomes very large if the flow of refrigerant in the condenser and the flow of the load fluid must be made to flow independently. There is a drawback.

Another is that when a mixed refrigerant is used, for example, the temperature of the refrigerant gas sent from the λ-stage compressor ♂ through the discharge pipe /7 is different from the temperature of the refrigerant reduced in pressure by the pressure reducing device /2. That's what it means. This will be explained using FIG.

This Figure 2 is a gas-liquid equilibrium diagram of a mixed refrigerant (non-azeotropic mixed refrigerant) under equal pressure, and shows that the refrigerant with a high boiling point T□
When a mixed refrigerant consisting of a refrigerant with a low boiling point Tm and a refrigerant with a low boiling point Tm is cooled, the temperature at point A on the k4 point curve becomes T.
Partial condensation begins at point A, and the temperature T at point B on the boiling point curve E
B indicates that all condensation is complete. Now, the state of the refrigerant gas sent from the first stage compressor is set to point A (pressure 1
)I+A4I formation On the other hand, the refrigerant (gas-liquid mixed state) whose pressure has been reduced by the pressure reducing device 16 has a pressure of p, expressed as a QC point, and a temperature of T. 9, the temperature becomes lower than the above-mentioned temperature TA.

As mentioned above, since there is a temperature difference between the refrigerant from the compressor and the refrigerant from the pressure reducing device, there is a drawback that heat exchange within the condenser cannot be performed effectively.

The object of the present invention is to provide an energy-saving heat pump with a compact condenser that eliminates the two drawbacks of the prior art described above.

Of the refrigerant that has been depressurized through the device to the condenser pressure of the pressure stage one stage lower than the above pressure stage, only the refrigerant is combined with the liquid refrigerant condensed in the condenser of the pressure stage one stage lower. , it is characterized in that it is configured so that it is returned to the evaporator through the lowest stage depressurization equipment without passing through the condensers in the subsequent stages.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 1/FIG. In these figures, the same reference numerals as in FIG. 7 indicate the same or equivalent parts.

FIG. 3 is a flow sheet showing the first embodiment, in which the liquid refrigerant in the evaporator is heated and evaporated by the heat source water fed through the piping 9, and the liquid refrigerant in the evaporator is evaporated. After that, the first stage pressure &
It gets sucked into the white machine. Of the gas compressed by the first stage compressor Hiroshi, for example, about 1/3 of the gas is discharged to the condenser B via the discharge pipe J, and the remaining 2/3 passes through the branch pipe 7 to the first stage compressor. being sucked into the machine. Similarly, for example, approximately //2 of the discharge gas of the first membrane compressor r is sent to the condenser via the discharge pipe 17, and the remaining //2 is sent to the suction section of the third stage compressor IO. , and is further compressed and discharged to the condenser//, where it is cooled by the load fluid as the heated fluid, which is the same as in FIG.

However, in this embodiment, the load fluid passing through each condenser is transferred by pump/2 to these three condensers 6. Three supercoolers 2/ are installed on the refrigerant downstream side of each bX Ad unit.

2, 2, and 23 in series in order to be heated. Therefore, this system having a plurality of condensers with different pressures, similar to the one shown in FIG. 13, the hot fluid at approximately 60°C is heated by io°C in each subcooler and condenser combination, and the temperature at the load fluid outlet /4' becomes approximately 20°C and is supplied to the load. On the other hand, the refrigerant gas is the top condenser/l
After condensing at 1<u, piping/! (Since the supercooler 23 is provided on the way to the pressure reducing device /j via i-, it is cooled by this supercooler 23, and further depressurized by the pressure reducing device /6.

In this way, by providing the supercooler λ3 before the pressure reducing device/B, the refrigerant is supercooled, so no flash gas is generated even if the refrigerant is subjected to the pressure reducing action by the pressure reducing device/6. Therefore, only the liquid refrigerant can be discharged without providing a separate gas-liquid divider. This depressurized refrigerant consists only of liquid refrigerant, joins with the liquid refrigerant condensed in the tear bath 2, is further sent to the supercooler 22, and after being cooled, is depressurized by the depressurizer. However, here too, since the refrigerant is supercooled, no Franche gas is generated, and it merges with the liquid refrigerant in the condenser 6 and beyond, and after being cooled in the supercooler 2/, the lowest pressure reducing device *, 20 and returns to the evaporator.

Figure μ is a pressure-enthalpy diagram of the heat pump of the first embodiment shown in the third factor, and points A and 81 are the first
The state of the refrigerant gas at the suction and discharge ports of the stage compressor is
Points 2 and 83 indicate the state of the refrigerant gas at the discharge ports of the second and third stage compressors, and points B3, B2 and B1 indicate the state of the refrigerant liquid at the outlets of the condenser //, ri and 2. , and also D'3
Point, D'2 point and 071 point are supercooler 23.22 and
The state of the refrigerant liquid at the outlet of 2/ is shown, and points 22, 51, and E indicate the state of the refrigerant liquid at the outlet of pressure reducing device/1. /! The shapes 1π of the refrigerant at the exits of P and 2o are shown respectively. As shown in the figure of Jin,
For example, the liquid refrigerant in the condenser// is in the subcooler 23, D
Since it is supercooled to point '3 (same temperature as the equivalent saturation 1J temperature of the condenser), even if the pressure is reduced by the pressure reducing device valley lz, it is clear that point B2 is in the liquid phase region. No flash gas is generated.

According to this third/embodiment, each pressure reducing device has a refrigerant top Dit.
Since the subcooler is installed in the 01ll, flash gas is not generated even if the pressure is reduced by the pressure reducing device, so the liquid refrigerant can be discharged without a separate gas-liquid separator, and the condensation Since the liquid refrigerant can be combined with the liquid refrigerant from the evaporator and returned to the evaporator through the lowest stage pressure reducing device without passing through the Cεε multiplier in the next stage and subsequent stages II4, liquid refrigerant accumulates especially at the bottom of the condenser in the low pressure stage. Therefore, both of the two drawbacks of the conventional device can be eliminated. In addition, the supercooler 2/ is the outlet refrigerant of the lowest stage M 6, which is shown in Fig. 51.
Since supercooling occurs at point 1 point 1, the cooling effect by the evaporator/VC (the difference in enthalpy between point A and point 1AiE ) can be increased. Note that the above-mentioned supercooler K's twisting action is similar to that of the other supercoolers 23. ．． The same can be said for 2.2.

FIG. 5 is a flow sheet showing the second embodiment, and shows the pressure reducing device/6. A gas-liquid separator, 2≠, 2j, is provided downstream of the refrigerant of the decompression equipment /O and /R in order to extract only the liquid refrigerant from the refrigerant after being depressurized at /F. In this example, liquid refrigerant from condensers l/ and
When the pressure is reduced by and/or, flash gas is generated, but in this gas-liquid separator, 2≠ and 2! The gas is sent to the next stage condenser and condensed, but the liquid refrigerant is combined with the condensed liquid from the condenser and sent to the next stage pressure reducing device.

61 is a pressure-enthalpy diagram of the heat pump shown in FIG. 5, for example, the liquid refrigerant (D
point s) is when the pressure is reduced by the pressure reducing device-16 B2
As shown by the dots, it is in a gas-liquid mixed state, and the gas is shown to be combined with the discharge gas from the second stage compression stage (point 82) and sent to the condenser (point B2). Note that this diagram is the same as the pressure-enthalpy diagram of the heat pump shown in FIG.

According to this second embodiment, liquid refrigerant can be effectively extracted from the refrigerant whose pressure has been reduced by the pressure reducing device by the gas-liquid separator, and the liquid refrigerant is combined with the liquid refrigerant from the tea supply. Since the liquid refrigerant can be returned to the evaporator through the lowest pressure reducing device without passing through the condensers of the next stage and subsequent stages, liquid refrigerant does not accumulate especially at the bottom of the condenser of the low pressure stage, and therefore Any of the drawbacks of the conventional device shown in FIG. 7 can be eliminated.

FIG. 7 is a flow sheet showing the third embodiment, in which both the supercooler in the first embodiment and the gas-liquid separator in the second embodiment are provided.

In this embodiment, for example, the refrigerant exiting the condenser // passes through a subcooler 23 and is then depressurized by a pressure reducing device /l, and the refrigerant gas contained therein is removed by a gas-liquid separator λ. The gas discharged from the second stage compressor is separated from the gas in the second stage compressor, and is condensed in the condenser.
and Feature g of the third embodiment can be combined.

FIG. So, the supercooler 2 just before the bottom killing decompression device FK20 is the most effective.
The structure is simplified by leaving only / and omitting the subsequent supercooler. However, this embodiment is equipped with a gas-liquid separator to separate the flash gas generated by the pressure reducing device. Therefore, the feature of the present invention is fully fulfilled.

The second diagram shows the pressure of the heat pump shown in the MJ' diagram.
It is an enthalpy diagram, and supercooling by supercooler 2/ is cooled at D'1 point pl, which results in freezing effect (I
It can be seen that A-11) is increasing.

FIG. 1Q is a flow sheet showing the jth embodiment,
Two condensers (// and 2) are provided, and the low-pressure side condenser B is used to collect the discharge gas from the first stage compressor≠ and the flash gas generated by the pressure reducing device/2 in the gas-liquid separator 2j. The separated refrigerant gas is combined with the refrigerant gas and introduced (7, the separated liquid refrigerant is passed through the supercooler) and then guided to the lowest pressure reducing device.

Even though this embodiment has a relatively simple configuration, it still has the above-mentioned functions that are characteristic of the present invention, such as saving energy and preventing liquid refrigerant from accumulating at the bottom of the condenser. The effect of the condenser is reduced, and the condenser can therefore be made more compact.

Figure 1/Figure 1 shows the pressure of the heat pump shown in Figure 1θ.
It is an enthalpy diagram.

In each of the above embodiments, the compressor was described as a multi-stage compressor, but the present invention is applicable to the case where two or more Tase compressors are connected in a row, and when a screw set or a reciprocating type compressor is operated. Of course, this also includes the case where λ or more compressors with a capacity of 8i1U are connected in series and operated. Further, although the description has been made regarding a narrowly defined heat pump that produces hot fluid, it goes without saying that the same device can also be applied to a refrigerator that produces cold fluid.

As explained above, in the present invention, the pressure of the refrigerant condensed in the condenser of the low pressure stage is reduced to the condenser pressure of the next stage using the pressure reducing device A, and then the liquid cooling II! i1. The structure is such that the liquid refrigerant is combined with the liquid refrigerant condensed in the condenser and returned to the illuminator without passing through the condensers in the next stage or later. There is no accumulation, and therefore the k-multiplier can be designed in a connected manner. In addition, by providing a supercooler that is cooled by the fluid to be heated in the condenser before the lowest pressure reducing device,
The refrigeration effect increases by 1, and the performance of the heat pump improves.

[Brief explanation of the drawing]

Figure 1 is a flow sheet of the conventional energy-saving heat pump developed earlier, Figure 2 is a diagram of the isobaric air-liquid flow of a mixed refrigerant,
ml) Figure 3 ny jr figure, figure 7, figure r and figure /Q
The quotient is the 70th sheet of the heat pump of the present invention;
The diagrams are four diagrams showing the pressure-enthalpy of the /, λ, ·, ゛, ≠ and j-th embodiments, respectively. /... Evaporator, ≠, 7, 10... Compressor, Otsu, ri. //... Condenser, /l, l, 20... Pressure reduction device ↑R
1,2/. ,! ,! ,? 3...1 supercooled rice bowl, 24', , 2J'
...gas/liquid fraction] 1 in a container. Figure 2 Figure 4 Figure 8 B/1

Claims (1)

[Claims] f. An evaporator, a plurality of condensers with different pressures, a multi-stage or plurality of compressors that send compressed gas at a pressure corresponding to each of these condensers, a plurality of pressure reducing devices, and these In an energy-saving heat pump consisting of piping connecting equipment, etc., the refrigerant condensed in any condenser other than the condenser with the lowest pressure is passed through a pressure reduction device to the condenser pressure of the pressure stage 97 stages lower than the above pressure stage. A heat pump characterized in that, of the refrigerant after depressurization and fc, only the liquid refrigerant is returned to the evaporator through the lowest stage pressure reducing device without passing through the condenser at the next stage or later. 2. Take out only the liquid refrigerant from the refrigerant condensed in the condenser of the lowest pressure stage/higher pressure stage, after reducing the pressure to the lowest stage condenser pressure via the pressure reducing device. 2. The heat pump according to claim 1, further comprising a supercooler cooled by the heated fluid to be heated in the condenser, which is provided upstream of the refrigerant C)v of the pressure reducing device. 3. After reducing the pressure of the refrigerant condensed in the condenser of the lowest stage, the lowest pressure stage, through the pressure reducing device to the condenser pressure of the lowest stage, only liquid refrigerant is removed. As a means for taking out the refrigerant, a gas-liquid separator is provided downstream of the refrigerant, and only the liquid refrigerant separated by the gas-liquid separator is sent to the evaporator through the lowest-stage pressure-reducing device without passing through the lowest-stage condenser. 1. The heat pump according to item 1 of the box. lA Evaporator, multiple condensers with different pressures, multistage or multiple compressors that send compressed gas at corresponding pressures to each of these condensers, multiple pressure reducing devices, and piping that connects these devices. In an energy-saving heat pump consisting of, etc., the refrigerant condensed in any condenser other than the condenser with the lowest pressure is reduced to the condenser pressure of the pressure stage pi stages lower than the above pressure stage through a pressure reducing device. Among refrigerants,
Only the liquid refrigerant is heated in the Maa device in the middle of the pipe that joins the softened liquid refrigerant in the condenser of the pressure stage and leads to the lowest stage pressure reducing device without passing through the condenser of the next stage or later. A heat pump characterized in that it is provided with a subcooler that is cooled by a fluid to be heated.