JPS61101757A - Cryostatic device - 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 the Invention The present invention relates to an improvement in a low temperature apparatus that uses a non-azeotropic mixed refrigerant to obtain a low temperature through one-stage compression.

Conventional technology Conventionally, a low-temperature device that uses a non-azeotropic mixed refrigerant to obtain a low temperature through one-stage compression is described in "Refrigerating Machine" by Shun Tezuka (Kyoritsu Shuppan, Vol. 1).
As shown on page 43 (first edition in 1965), a low-temperature device as shown in Figure 3 has been proposed. In Figure 4, 1 is a compressor, 2 is a condenser, and 3 is a gas-liquid separator connected to the outlet of the condenser. It is separated into a gas component containing many boiling point components and a lower liquid component containing many high boiling point components. Further, the lower liquid component is depressurized by the first throttle device 4 to generate cold, and is sucked into the compressor 1 via the heat exchanger 5. On the other hand, the gas component in the upper part of the gas-liquid separator 3 is condensed and liquefied in the heat exchanger 5.
The pressure is reduced by the expansion device 6, the temperature is generated by the evaporator 7, and then the fluid is sucked into the compressor 1.

The mode of operation of such a low-temperature device will be explained using a temperature versus concentration diagram (hereinafter referred to as a TX diagram) of a non-azeotropic mixed refrigerant.

Figure 5 shows that in a non-azeotropic refrigerant mixture consisting of two components, the fourth
High pressure of condenser 2 and evaporator 7 in the low temperature equipment shown in the figure
FIG. 2 is a TX diagram in a state where the low pressure is constant. The upper curve of the lens shape for each pressure represents the saturated gas line, and the lower curve represents the saturated liquid line. Above the saturated gas line is the superheated gas region, below the saturated liquid line is the supercooled liquid region, and the inside of the lens shape is gas and liquid. It shows a two-phase region in a shared state. In such a TX diagram, the fourth
When expressing the state of each part of the low temperature apparatus shown in the figure, points a-j in FIG. 4 correspond to points a-j in FIG. That is, the gas component is separated into a gas component and a liquid component in the gas-liquid separator 3, but the gas component contains more low-boiling point components, and after being condensed and liquefied in the heat exchanger 5 and reduced in pressure, it is transferred to the evaporator. 7 (between points h-i)
generates low temperatures. Therefore, compared to the mixed refrigerant concentration circulating in the compressor 1, more low-boiling point components flow in the evaporator 7, making it possible to obtain a lower temperature at the same low pressure. This is shown by the TX diagram sloping downward to the right when the horizontal axis represents the concentration of low boiling point components.

Problems to be Solved by the Invention As explained above, although the conventional low-auxiliary equipment is capable of obtaining low temperatures through one-stage compression, the temperature level is limited by the TX diagram of the non-azeotropic mixed refrigerant. The drawback was that there were limits to receiving. That is, in the low-temperature @ position shown in FIG. 3, the gas component and liquid component separated in the gas-liquid separator 3 are as follows.
This is because it is uniquely determined by the component refrigerant constituting the constant refrigerant of the saturated gas line and the saturated liquid line at high pressure shown in the TX diagram of FIG.

The purpose of the present invention is to eliminate the drawbacks of the conventional low-temperature equipment described above. Specifically, the refrigerant flowing through the evaporator has a lower boiling point component than the conventional one, compared to the mixed refrigerant concentration circulating through the compressor. By configuring it to allow a large amount of flow, it is possible to obtain a lower temperature than before even at the same low pressure.

Means for Solving the Problems The means for achieving the above object in the present invention is to provide a rectifier at intermediate pressure instead of the gas-liquid separator installed at high pressure, and to use a rectifier as a heating source at the bottom of the rectifier. The compressor discharge gas is used as a cooling source for the upper part of the rectifier by reducing the pressure of the liquid refrigerant extracted from the lower part of the rectifier. The high boiling point components are directly sucked into the compressor, while only the low boiling point components are depressurized and flowed into the evaporator.

Function The main function of the means according to the present invention is that since the rectifier is installed at an intermediate pressure position, the high-pressure discharge gas and the liquid refrigerant at the bottom of the rectifier are reduced to a low pressure and the cold temperature is reduced. It is now possible to secure a sufficient temperature difference between the two, and the high boiling point component and low boiling point component are separated into the bottom and top of the rectifier through gas-liquid contact inside the rectifier, making the temperature range wider than before. At the same time, only low boiling point components are allowed to flow into the evaporator to obtain a lower temperature than before.

Embodiment An embodiment of the low temperature apparatus according to the present invention will be explained with reference to FIG. In FIG. 1, 11 is a compressor, 12 is a discharge gas pipe,
13 is a condenser, 14 is a first throttle device, and 15 is a rectifier disposed at an intermediate pressure position. The rectifier 15 is filled with a filler 16. Further, a part of the liquid refrigerant extracted from the lower part of the rectifier 15 exchanges heat with the discharge gas pipe 12 via the first heat exchanger 17 and is returned to the lower part of the rectifier 15.
The remaining pressure is reduced in the second expansion device 18 and then transferred to the second heat exchanger 1.
9 and is sucked into the compressor 11. Furthermore, after the gas refrigerant extracted from the upper part of the rectifier 15 is condensed and liquefied in the second heat exchanger 19, a part is returned to the upper part of the rectifier 15, and the remaining part is depressurized in the third expansion device 20. After generating a low temperature in the evaporator 21, it is sucked into the compressor 11.

Next, there is shown a TX diagram showing the working mode of the low temperature apparatus according to the present invention in a state where the low pressure of TX of a non-azeotropic mixed refrigerant consisting of two components is constant, as in the conventional example.

In this TX diagram, when representing the state of each part of the cryogenic apparatus shown in FIG. 1, points a-Q in FIG. 1 correspond to points a-Q in FIG. 2. That is, inside the rectifier 15 disposed at an intermediate pressure position, among the refrigerant in a gas-liquid coexistence state flowing through the first throttle device 14, the gas refrigerant not only rises and the liquid refrigerant descends, but also 1 The liquid refrigerant flowing into the heat exchanger 17 is heated by the discharge gas pipe 12, and volatile low-boiling components become gaseous, rise in the rectifier 15, and are extracted from the upper part of the rectifier 15. The gas refrigerant is condensed in the second heat exchanger 19, and a portion is returned to the rectifier 15 and descends as a liquid refrigerant. At this time, inside the rectifier 15, the rising gas refrigerant and the descending liquid refrigerant come into gas-liquid contact in the contact area expanded by the filler 16, and the liquid refrigerant descending due to the rectifying action is richer in high-boiling point components. , the rising gas refrigerant becomes richer in low-boiling components. This state corresponds to the state of separation in multiple stages within the range surrounded by the saturated gas line and the saturated liquid line at intermediate pressure in the TX diagram of FIG.
At the bottom, the refrigerant is separated into a liquid refrigerant shown by point e, and at the top, it is separated into a gas refrigerant shown at point f, making it possible to separate the refrigerant with a wider concentration range than before. Therefore, the high boiling point components in the lower part are used to generate refrigeration in the second heat exchanger 19 via the second throttling device 18 and are sucked into the compressor 11 as they are, but the low boiling components in the upper part are The refrigerant is condensed and liquefied in the heat exchanger 19, reduced to a low pressure in the third throttle device 0, and then generated at a low temperature in the evaporator 21. The refrigerant flowing through the evaporator 21 contains more low-boiling point components than before. Because it flows, it is possible to obtain a lower temperature than before even at the same low pressure.

Next, a second embodiment of the low temperature apparatus according to the present invention will be described only with respect to the main parts around the rectifier shown in FIG. In FIG. 3, numbers 12 to 19 are the same components as in the embodiment shown in FIG. A flow control valve 21 is installed in the pipe that returns to the upper part of the rectifier 15 through the vessel 19.
It has been established. By using such a configuration, the mode of operation is similar to that of the embodiment shown in FIG.
The heat exchanger 17 in the illustrated embodiment is omitted, and the concentration separation width can be adjusted by the flow rate control valve 21.

As described in detail, the low temperature apparatus of the present invention is provided with a rectifier at an intermediate pressure position, uses compressor discharge gas as a heating source, and extracts gas from the bottom of the rectifier as a cooling source. Since the liquid refrigerant is used under reduced pressure, when it is separated into high boiling point components and low boiling point components by rectification as shown in Figure 2,
Even though the temperature is higher at the bottom of the rectifier and lower at the top, it is possible to maintain a sufficient temperature difference between the rectifier and the heat source, promoting the rectification action and expanding the separation width. It is possible. Furthermore, the low-temperature device of the present invention is configured so that only the low-boiling components separated in the upper part of the rectifier flow into the evaporator, making it possible to obtain a lower temperature than before.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a low-temperature device according to an embodiment of the present invention, Fig. 2 is a temperature vs. concentration diagram of a non-azeotropic mixed refrigerant to explain the working mode of the embodiment, and Fig. 3 is a diagram of a temperature vs. concentration diagram of a non-azeotropic mixed refrigerant. FIG. 4 is a configuration diagram of a low-temperature device of a different embodiment, FIG. 4 is a configuration diagram of a conventional low-temperature device of one embodiment, and FIG. 6 is a diagram showing the temperature of a non-azeotropic mixed refrigerant to explain the mode of operation of the conventional example shown in FIG. It is a versus concentration diagram. 11... Compressor, 12... Discharge gas pipe, 13... Condenser, 15... Rectifier,
21... Evaporator, 17.19... Heat exchanger, 14, 18, 20... Throttle device. Name of agent Patent attorney Toshio Nakao and one other person Figure 3 q Figure 4 Figure 5

Claims (2)

[Claims] (1) Enclose a non-azeotropic mixed refrigerant, compressor, discharge gas pipe,
A condenser, a first throttle device, and a rectifier are connected, and the liquid refrigerant at the bottom of the rectifier exchanges heat with the discharge gas pipe, and after extraction, passes through the second throttle device and exchanges heat with the gas refrigerant at the top of the rectifier. The gas refrigerant in the upper part of the rectifier is condensed and liquefied, and then a part of the refrigerant is returned to the upper part of the rectifier, and the remaining part flows into the evaporator through a third throttling device. cryogenic equipment. (2) A heat exchanger for exchanging heat between the rectifier refrigerant and a discharge gas pipe provided between the compressor and the condenser is provided in the lower part of the rectifier. The low temperature device according to item 1.