JP2008157618A - Two-stage compression refrigerating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and efficient two-stage compression refrigerating system having simplified device configuration as a whole. <P>SOLUTION: This two-stage compression refrigerating system comprises a two-stage compressor 1, an intercooler 13, a condenser 4, a liquid receiver 15, and an evaporator 2. The liquid receiver 15 incorporates the intercooler 13 so that the liquid receiver 15 serves as the intercooler 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a two-stage compression refrigeration system having a liquid receiver used for cooling a reaction furnace that needs to maintain a predetermined temperature in a chemical plant or the like.

  In a widely used two-stage compression refrigeration cycle, the low-pressure discharge gas from the first-stage compressor is cooled by an intermediate cooler, and the cooled gas is supplied from the intermediate cooler to the inlet side of the second-stage compressor. It is configured. As prior art of a refrigeration system having a liquid receiver, there are Patent Documents 1 and 2 and the like, and in this conventional apparatus, a device corresponding to the liquid receiver is called “receiver” or “liquid reservoir”. Yes.

FIG. 5 shows a two-stage compression refrigeration system used in a conventional chemical plant or the like.
In FIG. 5, this conventional system includes a two-stage compressor 1 composed of a first-stage compressor 1A and a second-stage compressor 1B, and an evaporator 2 that supplies superheated gas to the inlet side of the first-stage compressor 1A. The intermediate cooler 3 that receives and cools the superheated pressure gas discharged from the first stage compressor 1A, supplies the cooled gas to the inlet side of the second stage compressor 1B, and is discharged from the second stage compressor 1B. The condenser 4 for condensing the superheated high pressure gas, the receiver 5 for receiving the low-temperature cold liquid condensed and liquefied by the condenser 4 and returning it to the evaporator 2, and the condenser 4 being superheated when the output of the evaporator 2 is reduced. A first bypass valve line 6 that supplies gas back to the evaporator 2 and the second stage compressor 1B and a second bypass valve line 7 are configured.

Cooling water is circulated as a refrigerant to the condenser 4, cold water is supplied into the evaporator 2, and the cold water circulating inside is cooled by the heat absorption action due to liquid evaporation in the evaporator 2, thereby cooling water at a predetermined temperature. In this way, it is circulated and supplied to the cooled side.
The intermediate cooler 3 is generally gas-cooled by a spray contact with superheated gas entering the intermediate cooler 3 from the first stage compressor 1A.

  However, since the intermediate cooler 3 is provided independently, it is necessary to perform liquid level control and spray adjustment of the intermediate cooler 3 in both the intermediate cooler 3 and the liquid receiver 5, There is a problem that the burden of maintenance work increases. This also increases the installation space for the entire two-stage compression refrigeration system.

JP-A-9-89398 (FIG. 1) Japanese Patent Laid-Open No. 10-9721 (FIG. 1)

  In view of the above, it is an object of the present invention to simplify the device configuration of the entire two-stage compression refrigeration system and provide a low-cost and efficient two-stage compression refrigeration system for the conventional problems described above. .

  In order to solve the above problems, the present invention proposes the following means (1) and (2).

  (1) A first means is a two-stage compression refrigeration system comprising a two-stage compressor, an intermediate cooler, a condenser, a receiver and an evaporator, and the intermediate cooler is built in the receiver. The liquid receiver is also used as the intermediate cooler.

  (2) The second means is the two-stage compression refrigeration system according to the first means, wherein the intermediate cooler built in the liquid receiver is held in the cold liquid in the liquid receiver, A nozzle tube for ejecting superheated gas in a cold liquid so that heat exchange is possible is provided.

  The heat exchange between the superheated pressure gas and the cold liquid in the receiver is performed by blowing the superheated pressure gas into the cold liquid or by gas-liquid contact for supplying the superheated pressure gas into the cold liquid spray atmosphere. Heat exchange or a heat exchanger such as a double tube type or a plate type may be used. In short, the superheated pressure gas may be cooled with a cold liquid.

  According to the first aspect of the present invention comprising the first means, since the intermediate cooler is built in the liquid receiver and the liquid receiver and the intermediate cooling function are combined, the apparatus configuration of the entire two-stage compression refrigeration system This is a low-cost and efficient two-stage compression refrigeration system.

  The invention according to claim 2 comprising the second means exhibits the operational effect of the two-stage compression refrigeration system according to the first means, and jets superheated gas into the cold liquid of the liquid receiver. The superheated gas is efficiently heat-exchanged by the cold liquid, and energy saving can be achieved.

  In addition, the superheated pressure gas discharged from the first stage compressor is supplied to the receiver, and is cooled by exchanging heat with the cold liquid in the receiver, and the cooled gas is input to the second stage compressor. Therefore, it is not necessary to separately provide an intermediate cooler that has been provided conventionally, and the equipment configuration of the two-stage compression refrigeration system can be simplified, and the cost is efficient and low-stage compression refrigeration system.

  A two-stage compression refrigeration system according to the present invention will be described with reference to FIGS.

  FIG. 1 is a configuration diagram of a two-stage compression refrigeration system according to Embodiment 1 of the present invention, FIG. 2 is an explanatory view showing an enlarged P part of FIG. 1, and FIG. 3 is along the AA arrow in FIG. It is sectional drawing. FIG. 4 relates to Embodiment 2 of the present invention, and is an explanatory view corresponding to FIG.

  The present two-stage compression refrigeration system shown in FIG. 1 supplies superheated gas to a two-stage compressor 1 including a first-stage compressor 1A and a second-stage compressor 1B, and to the inlet side of the first-stage compressor 1A. The evaporator 2, the intermediate cooler 13 that receives and cools the superheated pressure gas discharged from the first stage compressor 1A, supplies the cooled gas to the inlet side of the second stage compressor 1B, and the second stage compression A condenser 4 that condenses the superheated high-pressure gas discharged from the machine 1B, a receiver 15 that receives the low-temperature cold liquid condensed and liquefied by the condenser 4 and returns it to the evaporator 2, and a reduction in the output of the evaporator 2 A first bypass valve line 6 that supplies superheated gas from the condenser 4 to the evaporator 2 and a second bypass valve line 7 that supplies superheated gas to the cooling gas line 17 are configured.

  As shown in FIGS. 1 and 2, an intermediate cooler 13 is built in the liquid receiver 15, and the liquid receiver 15 also serves as the intermediate cooler 13. The intermediate cooler 13 is configured by a nozzle tube 13B that is held in the cold liquid 15C in the liquid receiver 15 and that jets the superheated pressure gas G as the bubble gas g in the cold liquid 15C so that heat can be exchanged. ing.

  The intermediate cooler 13 includes a nozzle tube 13B having both ends closed and a large number of gas ejection holes 13C provided in the length direction and symmetrically, and a superheated gas introduction tube connected upward to the central portion of the nozzle tube 13B. 13A, the end of the superheated gas introduction pipe 13A is vertically penetrated through the body wall of the liquid receiver 15 and the superheated gas introduction pipe 13A is fixedly supported on the body wall of the liquid receiver 15 so that the nozzle pipe 13B is disposed at a height at which the entire 13B is horizontally immersed in the cold liquid 15C in the liquid receiver 15 at a predetermined depth.

  Further, the gas ejection hole 13C of the nozzle tube 13B is provided so as to be able to discharge the superheated gas G obliquely outward and downward to the lower side of the nozzle tube 13B (see FIG. 3), as shown in FIG. In addition, it is provided at a predetermined aperture ratio in the form of a single row perforated plate or a perforated plate. The nozzle tube 13B is not limited to a circular cross section, and a pipe material having an arbitrary cross section may be used.

  The liquid receiver 15 is separated from one end of the nozzle tube 13B, and a cold liquid introduction pipe 15A is provided from the upper side, and the liquid receiver 15 receives liquid at an upper part near the end opposite to the cold liquid introduction pipe 15A. An outlet pipe 13D for the gas cooled in the vessel 15 is provided. In FIG. 2, 13E is a filter provided inside the liquid receiver 15 of the gas outlet pipe 13D.

  The inlet pipe 13A of the intercooler 13 built in the liquid receiver 15 is connected to the discharge port of the first stage compressor 1A and the superheated pressure gas pipe 16 so that the superheat discharged from the first stage compressor 1A. Pressure gas is supplied to the liquid receiver 15. Further, the gas outlet pipe 13D on the liquid receiver 15 is connected to the inlet of the second stage compressor 1B by the cooling gas pipe 17, and is cooled by gas-liquid contact with the cold liquid of the liquid receiver 15 Is supplied to the inlet side of the second stage compressor 1B.

  Further, the discharge port of the second stage compressor 1B and the condenser 4 are connected to the liquid receiver 15 by the pipe line 18 and the cold liquid introduction pipe 15A on the liquid receiver 15 is connected to the liquid receiver 15 by the cold liquid outlet pipe 19 of the condenser 4. The evaporator 2 and the evaporator 2 are connected to the inlet side of the first stage compressor 1 </ b> A by a pipe 21. In FIG. 1, reference numerals 10 and 11 denote on-off valves.

  Thus, in this two-stage compression refrigeration system, the gas vaporized by the evaporator 2 is supplied to the inlet side of the first-stage compressor 1A through the pipe 21 through the filter 2A, and compressed in the container. The first stage superheated gas having a constant pressure is continuously sent from the discharge port of the first stage compressor 1A to the intercooler 13 through the pipe line 16. The gas cooled by the intermediate cooler 13 is supplied to the inlet side of the second stage compressor 1B through the cooling gas pipe 17 and is highly compressed in the container, and is sent from the discharge port to the condenser 4 through the pipe 18. It is done.

  The cold liquid condensed by the condenser 4 is sent to the liquid receiver 15. When the gas output of the evaporator 2 decreases, the second stage superheated gas passes from the condenser 4 through the first bypass valve line 6 and the second bypass valve line 7 to the evaporator 2 and the second stage compressor 1B, respectively. Is returned to the gas supply line to maintain the predetermined operating state of the first stage compressor 1A and the second stage compressor 1B.

  The liquid receiver 15 maintains the received cold liquid at a predetermined depth and sequentially feeds it to the evaporator 2. Cold water circulates from the cooled side in the evaporator 2, and the cold water is re-cooled by the heat absorption action by liquid evaporation in the evaporator 2 to be supplied to the cooled side (not shown) as low-temperature cold water.

  In addition, as shown in FIGS. 1 and 2, during this refrigeration cycle, the intermediate cooler 13 built in the receiver 15 has a refrigerant liquid having a predetermined depth that is initially present in the receiver 15. The held superheated gas is supplied to the intermediate cooler 13 while maintaining a predetermined depth through the gas ejection holes 13C of the nozzle tube 13B.

  In addition, when the superheated gas having a predetermined pressure supplied from the first stage compressor 1A to the intermediate cooler 13 enters the nozzle tube 13B from the gas introduction tube 13A, the cold liquid surface in the nozzle tube 13B with its own gas pressure. Is pushed down to the height level of the gas ejection hole 13C, and as shown in FIG. 3, the gas is ejected as bubbles in the cold liquid on both the left and right sides from the gas ejection hole 13C into the intermediate cooler 13, and the superheated gas is rapidly cooled directly. As a result, the liquid is stored in the space in the liquid receiver 15 on the cold liquid.

  At this time, the action of the superheated gas having a predetermined pressure in the intermediate cooler 13 depressing the internal cold liquid changes depending on the interval L, the number, and the diameter D of the gas ejection holes 13C. Further, the height of the gas ejection hole 13C and the ejection angle α influence the bubble rising curve in the cold liquid. Each of these conditions is to select a predetermined arrangement, number, diameter, height, and injection angle α of the gas ejection holes 13C according to the flow rate, temperature and pressure of the superheated gas supplied to the intercooler 1. is required.

  Further, since the intermediate cooler 13 uses the cold liquid 15C in the liquid receiver 15 as the refrigerant liquid in the liquid receiver 15 as it is, the intermediate cooler 13 is controlled only by controlling the liquid level of the cold liquid in the liquid receiver 15. And the receiver 15 can be controlled.

  In the embodiment described above, in the two-stage compression refrigeration system, the intermediate cooler 13 built in the receiver 15 is held at a predetermined depth in the cold liquid in the receiver 15, The nozzle tube 13B that jets superheated gas so that heat can be exchanged efficiently in the liquid is used for optimal design.

According to the above-described two-stage compression refrigeration system, the following effects can be obtained.
(1) Since the intermediate cooler is provided in the liquid receiver, the installation space for the intermediate cooler, the occupation of the connection pipe line, the entire equipment of the refrigeration apparatus are simplified, and the installation space is reduced.
(2) Since the intermediate cooler is built in the liquid receiver, the cold liquid held in the liquid receiver can be used as it is as the intermediate cooling refrigerant liquid, and separate refrigerant liquid level control for intermediate cooling is unnecessary. Thus, the control and maintenance of the entire apparatus is simplified.
(3) Since the intermediate cooler is built in the receiver and the superheated gas supplied to the intermediate cooler is brought into bubble contact with the cold liquid in the receiver to exchange heat, boiling heat transfer occurs. In addition, highly efficient heat transfer cooling is possible, and the cooling capacity is greatly improved.
(4) For this reason, the efficiency of the entire refrigeration system is improved, and the installation space and initial cost can be greatly reduced.

  A two-stage compression refrigeration system according to a second embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, the gas-liquid spray contact type intermediate cooler 23 is built in the receiver 25, and the receiver 25 is also used as the intermediate cooler 23, as shown in FIG. A portion surrounded by a dotted line indicates a shared portion of the intermediate cooler 23.

  The liquid receiver 25 includes a cold liquid introduction pipe 25A connected to the pipe line 19 from the condenser 4 in FIG. 1 and a cold liquid return pipe 25B to the evaporator 2 above and below the central portion. Connected to.

  Further, a superheated gas introduction pipe 23A connected to the superheated pressure gas pipe 16 from the discharge port of the first stage compressor 1A in FIG. 1 and a cold liquid introduction pipe 25A are received near one end of the liquid receiver 25. A cold liquid spray pipe 23B is provided in the upper part of the liquid vessel 25 and supplied with the cold liquid from the cold liquid supply pipe 25C. Further, a gas outlet pipe 23D connected to the cooling gas pipe 17 to the inlet side of the second stage compressor 1B and a filter 23E are provided near the end opposite to the superheated gas introduction pipe 23A.

  That is, in this embodiment, the intermediate cooler 23 uses the cold liquid supplied to the main body of the liquid receiver 25 and the liquid receiver 25 as it is for the intermediate cooler 23 and is supplied to the liquid receiver 25. Spray cooling with cold liquid is done. Other configurations are the same as those of the first embodiment (FIG. 1).

  Therefore, in the system of the present embodiment, the superheated gas sent from the first stage compressor 1A of FIG. 1 to the intercooler 23 of FIG. 4 enters the space inside the main body of the liquid receiver 25 through the superheated gas introduction pipe 23A. 1 and is cooled by the cold liquid sprayed from the cold liquid spray pipe 23B in the liquid receiver 25, and the cooled gas passes through the filter 23E and the gas outlet pipe 23D and enters the second stage compressor 1B of FIG. Supplied to the side.

  During this time, the low temperature cold liquid condensed and liquefied by the condenser 4 of FIG. 1 enters the liquid receiver 25 through the cold liquid introduction pipe 25A of FIG. 4, and then the cold liquid 25D at the bottom of the liquid receiver 25 is Then, the liquid is sequentially fed from the cold liquid return pipe 25B to the evaporator 2 of FIG.

According to the above-described two-stage compression refrigeration system, the following effects can be obtained.
(1) Since the intermediate cooler 23 is provided in the liquid receiver 25 and used as a combined device, the installation space for the intermediate cooler 23 and the occupied occupancy of the connecting pipe line are simplified and the installation space is reduced. To do.
(2) The configuration of the intermediate cooler 23 built in the liquid receiver 25 in order that the intermediate cooler 23 main body is also used as the liquid receiver 25 main body and only the cooling function of the intermediate cooler 23 is built in the liquid receiver 25. Is significantly simplified and economical.
(3) Since the intermediate cooling is performed in the liquid receiver 25 body, the cold liquid supplied into the liquid receiver 25 can be used as it is as the refrigerant liquid for intermediate cooling, and separate refrigerant liquid level control for intermediate cooling is unnecessary. As a result, the control and maintenance of the entire apparatus is simplified.
(4) Therefore, the efficiency of the refrigeration apparatus can be improved and the installation space and initial cost can be greatly reduced.

  In short, in Examples 1 and 2, the superheated pressure gas discharged from the first stage compressor 1A is supplied to the liquid receiver (15 or 25), and is cooled by exchanging heat with the cold liquid in the liquid receiver. Since the cooled gas is supplied to the inlet side of the second-stage compressor 1B, it is not necessary to separately provide an intermediate cooler that has been conventionally provided, and the equipment configuration of the two-stage compression refrigeration system can be simplified, and at low cost. It is an efficient two-stage compression refrigeration system.

Note that the cold liquid and the superheated pressure gas may be subjected to heat exchange in which the liquid is directly brought into gas-liquid contact in the stored liquid.
In addition, as described in the above embodiments, the present invention is a system that includes a two-stage compressor, an intercooler, a condenser, a receiver, and an evaporator to perform a two-stage compression refrigeration cycle. It can be said that the liquid receiver is configured to incorporate and also use an intercooler.

  The present invention is not limited to the above-described embodiments, and can be appropriately modified as necessary. In addition, each component in the embodiment includes those that can be easily assumed by those skilled in the art and those that are substantially the same.

1 is a configuration diagram of a two-stage compression refrigeration system according to Embodiment 1 of the present invention. It is explanatory drawing which expands and shows the P section of FIG. It is sectional drawing which follows the AA arrow of FIG. FIG. 7 is an explanatory diagram corresponding to Example 2 of the present invention and corresponding to FIG. 2. It is a block diagram of the conventional two-stage compression refrigeration system.

Explanation of symbols

1 2nd stage compressor 1A 1st stage compressor 1B 2nd stage compressor 2 Evaporator 2A Filter 3 Intermediate cooler 4 Condenser 5 Liquid receiver 6 First bypass valve line 7 Second bypass valve line 13 Intermediate cooling 13A Superheated gas introduction pipe 13B Nozzle pipe 13C Gas ejection hole 13D Gas outlet pipe 13E Filter 15 Receiver 15A Cold liquid introduction pipe 15B Cold liquid return pipe 15C Cold liquid 23 Intermediate cooler 23A Superheated gas introduction pipe 23B Cold liquid spray pipe 23D Gas outlet pipe 23E Filter 25 Receiver 25A Cold liquid introduction pipe 25B Cold liquid return pipe
25C Cold liquid supply pipe 25D Cold liquid

Claims (2)

  In a two-stage compression refrigeration system including a two-stage compressor, an intermediate cooler, a condenser, a receiver, and an evaporator, the intermediate cooler is built in the receiver, and the receiver receives the intermediate cooling. A two-stage compression refrigeration system characterized in that it is also used as a container. 2. The two-stage compression refrigeration system according to claim 1, wherein the intermediate cooler incorporated in the liquid receiver is held in the cold liquid in the liquid receiver and is superheated so that heat can be exchanged in the cold liquid. A two-stage compression refrigeration system comprising a nozzle pipe for ejecting gas.

Images