JPS60256767A - Regulator for quantity of refrigerant liquid circulated in refrigerator - 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 Application of the Invention] The present invention relates to a refrigerant liquid circulation amount adjusting device suitable for refrigerators, particularly large capacity and high head refrigerators.

[Background of the invention]

Conventionally, orifice plates and float valves have been generally used as refrigerant liquid circulation rate adjusting devices for refrigerators, but the use of the former orifice plate reduces the refrigeration load and lowers the flow rate to below the optimum design flow rate of the orifice. Furthermore, when the temperature of the cooling water in the condenser rises and exceeds the optimum design pressure of the orifice, refrigerant gas is drawn in and flows into the evaporator together with the refrigerant liquid. Since this refrigerant gas is drawn into the compressor without effectively acting on refrigeration, problems such as increasing the power required for the compressor occur.

On the other hand, the use of the latter float valve, which opens and closes using the buoyancy of the float ball, has extremely few problems like the above-mentioned orifice plate, and works effectively even under partial loads of the refrigerator, but the refrigeration capacity The larger the diameter of the float valve, the larger the diameter of the float valve. When the cooling water temperature of the condenser is high and when the evaporation pressure is low such as in a brine refrigerator.

The pressure difference before and after the float valve becomes large, and the torque required to operate the float valve also becomes large, which not only poses problems in structural design such as increasing the diameter of the float ball and increasing the size of the float chamber, but also causes economical problems. There is a fear that it may damage your sexuality.

[Purpose of the invention]

In view of the above, the present invention provides a relatively small and low-cost float for use in a large-capacity refrigerator, a refrigerator with a large pressure difference between a condenser and an evaporator, and a large pressure difference before and after one float valve. The object of the present invention is to provide a valve type refrigerant liquid circulation amount adjusting device.

[Summary of the invention]

In order to achieve the above object, the present invention provides an evaporator.

In a refrigerator in which a compressor, a condenser, a float chamber, and a float valve are operatively connected to a flash economizer or the like having a built-in refrigerant liquid flow rate adjustment device, communication between the float chamber of the refrigerant liquid flow rate adjustment device and the flash duct is provided. The float valve is characterized in that a separate opening is provided in the float valve in parallel with the float valve.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 indicates a built-in eliminator 12, an evaporator through which a cooling pipe 13 passes, and reference numeral 2 indicates a centrifugal tube having first to third stage impellers 3A to 3C built in and equipped with an inlet guide vane 13. The compressor 4 is a condenser through which a cooling pipe 15 passes. 5A.

5B is the first. In the second flash economizer, this first
The flash economizer 5A is connected to the inlet of the third stage impeller 3C via a pipe 18, and the second flash economizer 5B is connected to the inlet of the second stage impeller 3B via a pipe 19. .

The first economizer 5A is a first economizer. The second refrigerant liquid shield ring amount adjustment device w6, 7 and the first refrigerant liquid circulation amount adjustment device 6
It consists of a flush duct 9A” that connects to the eliminator IIA and an eliminator IIA.
JR[514'j%m3CO7D([[* 'i' has been passed.

As shown in FIGS. 2 and 3, the first refrigerant liquid circulation amount adjusting device M6 includes a float chamber 6A communicating with the flash duct 9A via a communication port 10, and a float 6C arranged in parallel with the communication port 10. with valve 6B and separate opening 6
D, for example, an orifice plate or a butterfly valve, and a refrigerant liquid swirl prevention plate 6E, and the float chamber 6A communicates with the condenser 3 via a refrigerant liquid introduction pipe 16. The second refrigerant liquid circulation amount adjusting device 7 includes a float chamber 7A and a float valve 7B.

On the other hand, the second economizer 5B is connected to the float chamber 7A.
and the float chamber 8A of the third refrigerant liquid circulation amount adjusting device 8, which is connected to the inlet side of the second stage impeller 3B and the evaporator 1 via piping 19, 20, and the piping 2.
1. A float valve 8B provided at the connection port between the float chamber 8A and the float chamber 8A, and a flush duct 9B communicating with the float valve 7B via piping 17. Eliminator 1'I
It is composed of B.

Next, the operation of this embodiment configured as described above will be explained.

The refrigerant gas generated in the evaporator 1 is sucked into the centrifugal compressor 2 via the inlet guide vent 14, and is passed through the impellers 3A to 3C.
The refrigerant gas, which has been pressurized to high pressure and high temperature, is introduced into the condenser 4. This introduced refrigerant gas is transferred to the cooling pipe 15.
In the case where the refrigerant liquid is cooled and liquefied by the cooling water flowing therethrough and collected in the float chamber 6A of the first refrigerant liquid circulation amount adjusting device 6 in the first economizer 5A through the pipe 16, the float valve 6B is A refrigerant liquid amount corresponding to the refrigeration load is introduced into the flash duct 9A while acting to maintain the refrigerant liquid level 21 for liquid sealing so that the refrigerant gas does not blow through. The refrigerant liquid spouted from this flash duct 9A is transferred to the float chamber 7A and the pipe 1.
8 and is depressurized before being sucked into the third stage impeller 3C. Due to this pressure drop, some of the refrigerant liquid evaporates and becomes gas, but this refrigerant gas is sufficiently separated from the liquid by the eliminator 10A and guided to the third stage impeller 3c, and then discharged from the second stage impeller 3B. It is sucked into the third stage impeller 3C together with the gas.

On the other hand, the refrigerant liquid is introduced into the float chamber 7A of the second refrigerant liquid circulation amount adjusting device 7, and thereafter the float chamber 8A and the float valve 8 of the third refrigerant liquid circulation amount adjusting device 8 are introduced in the same manner as described above.
A refrigerant liquid corresponding to the refrigeration load is effectively supplied to the evaporator 1 through B and piping 20. In the evaporator 1, the refrigerant liquid performs a freezing action by removing heat from the cold water flowing through the cooling pipe 13. At this time, the evaporated refrigerant gas is again supplied to the centrifugal compressor 2, and the above-mentioned refrigeration cycle is repeated.

FIG. 4 is a diagram showing the operation of the centrifugal compressor.

From this figure, the amount of refrigerant liquid 4I is determined by curves 25 and 2 depending on the load.
It is understood that the flow rate changes between 6 and 6.

A curve 25 shows the operation when the temperature of the cooling water in the condenser 4 changes when the inlet side vane 14 provided at the impeller inlet of the centrifugal compressor 2 is fully open.

On the other hand, curve 1 26 shows the operation when the temperature of the cooling water changes at the minimum opening of the inlet 4 and the side vane 14 just before reaching the surging state. The refrigerant liquid circulation amount shown on the biconvex lines 25 and 26 is the minimum required refrigerant liquid circulation amount to safely operate the refrigerator.

In the full load operation shown at point a in FIG. 4, the refrigerant liquid collected in the float chamber 6A in FIG. 2 flows out from both the float valve 6B and the orifice plate 6D to the flush duct 9A. Then, as the refrigerant circulation amount decreases due to a decrease in the refrigerating load, the refrigerant liquid level falls, and the float balls 6C floating on the refrigerant liquid level also fall. Therefore, the float valve 6B operates in the closing direction and maintains a minimum liquid level that does not impair the liquid sealing effect of the refrigerant gas.

When the load further decreases and reaches point b (FIG. 4), the float valve 6B is fully closed, so that the minimum amount of refrigerant required for stable operation of the refrigerator is supplied via the orifice 6D.

In general, the diameter of the float valve 6B is based on the refrigerant liquid circulation amount when the centrifugal compressor is operated at full load at the lower limit of the cooling water temperature of the condenser 4 determined as the operating conditions of the refrigerator. Determined by This maximum refrigerant circulation amount is usually approximately 120% of the refrigerant liquid circulation amount at the specification point.

On the other hand, the refrigerant capacity of the centrifugal compressor can be adjusted by opening and closing the inlet vane 14 provided at the inlet of the impeller.
This is done by adjusting the suction air volume. In this case, the minimum opening degree of the inlet guide vane 14 is limited to the point at which the surging state is reached, and the refrigerator is not operated at an opening degree below this, and the amount of refrigerant liquid circulating at this time is limited to the point at which the surging state reaches. This is the minimum refrigerant liquid circulation amount corresponding to load reduction.

That is, the above-mentioned minimum refrigerant liquid circulation amount is the minimum required refrigerant liquid circulation amount in order to stably operate the refrigerator with the minimum load, and is approximately 20 to 3 times the refrigerant liquid circulation amount at the specification point.
0%, and 24-36% for the maximum liquid circulation amount.

From the above, the maximum refrigerant liquid circulation amount that requires adjustment of the refrigerant liquid circulation amount in response to load changes is 76 to 64% of that amount, and this is the refrigerant liquid circulation amount that is shared by the float valve 6B, which accounts for the remaining 24 to 34%. can be assigned to an opening other than the float valve 6B. Since it is possible to expand the maximum refrigerant liquid circulation amount shared by at least the openings 6D other than the flow valve 6B, such as the orifice plate or the butterfly valve, to about 40%, the load factor of the float valve 6B is further reduced. Since the torque required to operate the float valve 6B is reduced to 60%, the float valve 6B can be made smaller.

In the refrigeration cycle of this embodiment described above, two flash economizers and three refrigerant liquid circulation amount adjustment devices are used, but the present invention is not limited to this, and one flash economizer and one refrigerant liquid circulation amount adjustment device are used. A similar effect can be obtained when using .

〔Effect of the invention〕

As explained above, according to the present invention, the float valve and the opening (
By installing an orifice plate), 60% of the maximum refrigerant circulation amount can flow out from the float valve and 40% from the orifice plate, so the shaft torque for operating the float valve can be significantly reduced (approx. 40%), it is possible to downsize not only the float chamber and the float but also the entire device, simplifying the structural design and reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a refrigeration cycle of a refrigerator equipped with an embodiment of the refrigerant liquid circulation amount adjusting device of the present invention, FIG. 2 is a detailed sectional view of the refrigerant liquid circulation amount adjusting device of FIG. 1, and FIG. 2 is a sectional view taken along line A-A in FIG. 2, and FIG. 4 is an explanatory diagram of the operation of the centrifugal compressor shown in FIG. 1. 1... Evaporator, 2... Centrifugal compressor, 4... Condenser, 5A. 5B...Flash economizer, 6,7...Refrigerant liquid circulation amount adjustment device, 6A, 7A...Float chamber, 6B
. 7B... Float valve, 6D... Orifice plate or butterfly valve, 9A... Flush duct, 10... Communication section.

Claims (1)

[Scope of Claims] 1. In a refrigerator comprising an evaporator, a compressor, a condenser, and a flash economizer or the like having a built-in refrigerant liquid flow rate adjustment device consisting of a float chamber and a float valve, the refrigerant A refrigerant liquid circulation amount adjusting device for a refrigerator, characterized in that a separate opening is provided in a communication portion between a float chamber and a flash duct of the liquid flow rate adjusting device in parallel with the float valve. 2. The refrigerant liquid circulation amount adjusting device according to claim 1, wherein the separate opening provided in parallel with the float valve is formed by providing an orifice plate or a butterfly valve.