JPS6125993B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an air extraction device for an absorption type water chiller/heater.

A conventional automatic air extraction device will be explained with reference to FIG.

The absorption type water chiller/heater includes an evaporator 1, an absorber 2, a regenerator 3, a condenser 4, a heat exchanger 5, a solution pump 6, and a refrigerant pump 7.

The evaporator 1 includes a cold water tube group 1a, the absorber 2 includes a cooling water tube group 2a, the regenerator 3 includes a heating tube group 3a, and the condenser 4 includes a cooling water tube group 4a. The solution pump 6 sends the diluted solution in the absorber 2 to the regenerator 3 via the heat exchanger 5 and the supply pipe 8, and also distributes a part of it from the header 9 to the cooling water pipe group 2a of the absorber 2. Further, the solution sprayed from the head 9 is mixed with a concentrated solution returned to the absorber 2 from the regenerator 3 via the return pipe 10. The refrigerant pump 7 sprays the refrigerant liquid in the refrigerant tank 11 connected to the evaporator 1 from the header 12 to the cold water pipe group 1a.

The air bleed device includes an air bleed chamber 13, a gas-liquid downpipe 14, a gas-liquid separator 15, an air storage tank 16, a pipe 16a connecting the gas-liquid separator 15 and the air storage tank 16, and an air bleed pipe 1.
7, a solution introduction pipe 18, a solution return pipe 19, a cooling coil 20, a solenoid valve 21, an exhaust pump 22, and a pressure relay 23. Such an air extraction device is disclosed, for example, in Japanese Utility Model Application No. 48-85242.

The operation of this bleed device is to introduce a part of the solution discharged from the solution pump 6 into the bleed chamber 13 via the solution introduction pipe 18, while introducing cold water from the cooling coil 20 into the bleed chamber 13.
Refrigerant or cooling water is circulated to bring the bleed chamber 13 to a low temperature and low pressure. As a result, non-condensable gas is drawn into the bleed chamber 13 from the absorber 2 or the condenser 4 via the bleed pipe 17. At this time, the refrigerant vapor also flows into the bleed chamber 13 and is absorbed into the solution.

The non-condensable gas in the bleed chamber 13 mixes with the solution flowing down the gas-liquid down pipe 14 and is carried to the gas-liquid separator 15, where it is separated and stored in an air storage tank 16. On the other hand, the solution in the gas-liquid separator 15 is transferred to the solution return pipe 19
It returns to absorber 2 via .

When a predetermined amount of non-condensable gas accumulates in the storage tank 16, the pressure relay 23 detects this and operates to start the exhaust pump 22 and open the solenoid valve 21 to discharge the non-condensable gas in the storage tank 16. .

When the pressure in the storage tank 16 drops to a predetermined value during evacuation, the pressure relay 23 operates to close the solenoid valve 21 and stop the evacuation pump 22.

According to such an air bleed device, when non-condensable gas is drawn into the bleed chamber 13 from the absorber 2 or the condenser 4, the refrigerant vapor that flows together is sucked into the exhaust pump 22, and the oil used in the exhaust pump 22 is absorbed. Early deterioration will reduce the risk of deterioration.

However, the maximum pressure of the non-condensable gas accumulated in the storage tank 16 is the sum of the pressure of the absorber 2 and the pressure corresponding to the liquid column H. (flows into the absorber 2 through the gas) Therefore, the maximum pressure of the non-condensable gas that can be stored in the storage tank 16 is very low, and the storage capacity per volume of the storage tank 16 is small. Therefore, the exhaust pump 22 must be operated frequently, and the range of pressure change in the storage tank 16 is small, so that there are times when the non-condensable gas has accumulated to the extent that it should be exhausted and the exhaust has reached a point where the exhaustion has to be stopped. At times, it is very difficult to operate the pressure relay 23, that is, to perform proper exhaust work.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air extraction device that can appropriately exhaust non-condensable gas. A feature of this invention is that an inverted U-shaped rising portion is formed in the solution return channel that returns the solution from the gas-liquid separator to the absorber, rising from the gas-liquid separator to a predetermined height. Therefore, the pressure of the non-condensable gas accumulated in the storage tank is increased.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 shows an embodiment of the present invention. In FIG. 2, the same reference numerals are given to the same or equivalent parts as in the prior art, and the explanation thereof will be omitted. The solution return pipe 24 connecting the gas-liquid separator 15 and the bottom of the absorber 2 extends to a position higher than the liquid level 2b in the absorber 2 and slightly lower than the open end of the gas-liquid downcomer pipe 14 in the bleed chamber 13. Standing up section 2
It consists of an inverted U-shaped tube with 4a.

This solution return pipe 24 does not have to be an inverted U-shaped pipe, and after rising to a position higher than the liquid level 2b and slightly lower than the open end of the gas bleed pipe 13 of the gas-liquid descending pipe 14, the solution in the absorber 2 Any channel that communicates with the inside may be used.

The gas-liquid separator 15 and the storage tank 16 are connected by a side passage 25, and two liquid level relays 2 are installed in this side passage 25.
6 and 27 are arranged. One liquid level relay 2
6 is installed near the same level as the liquid level 2b of the absorber 2, and the other liquid level relay 27 is installed at a position slightly lower than the top of the rising portion 24a of the solution return pipe 24.

One liquid level relay 26 starts the exhaust pump 22 and opens the solenoid valve 21, and the other liquid level relay 26
7 closes the electromagnetic valve 21 and stops the exhaust pump 22.

The oil trap 2 is used as an auxiliary device for the exhaust pump 22.
8. A check pressure relay 29 for checking the degree of vacuum attainment, and a solenoid valve 30 that opens and closes in conjunction with this pressure relay 29 are provided, and in the event of a power outage or an unexpected accident, air and oil will pass through the bleed tank 16. This prevents the water from flowing back into the hot and cold water machine.

Next, the operation of this embodiment will be explained.

The operations until the noncondensable gas and the solution are separated in the gas-liquid separator 15 are the same as those of the conventional system, so they will be omitted and the following operations will be explained step by step.

The non-condensable gas separated by the gas-liquid separator 15 is stored in an air storage tank 16. On the other hand, the solution in the gas-liquid separator 15 is pushed up to the top of the rising portion 24a by the head corresponding to the liquid column height ^H1 , and then descends and returns to the absorber 2.

Since there is a considerable liquid level difference of H ₁ - _{H 2} between the liquid level 2b of the absorber 2 and the open end of the gas-liquid downcomer pipe 14 in the bleed chamber 13, there is a head difference between the absorber 2 and the bleed chamber 1.
Since the pressure difference with 3 is extremely small, it seems that the solution return pipe 24 causes a siphon effect.
However, the siphon effect does not occur in situations where the interior of the machine is maintained at a high vacuum, such as in an absorption type water cooler/heater.

The reason for this is that the siphon effect occurs when a suction pressure corresponding to the liquid column of H ₁ - _{H 2} acts, but in an absolute vacuum there is no pressure lower than absolute vacuum, so the suction pressure is generated. do not have.

However, although the pressure in the absorber 2 and the bleed chamber 13 is generally a high vacuum of about 7 mmHg, it is not an absolute vacuum, so there is a slight possibility that a siphon effect will occur.

However, since the suction pressure that causes the siphon action is lower than the saturated vapor pressure of the solution, the refrigerant in the solution evaporates and the gas phase 31 at the saturated vapor pressure is transferred to the rising part 24a of the solution return pipe 24.
The presence of this gas phase 31 completely prevents siphon action.

The amount of solution passing through the solution return pipe 24 is the same as the amount flowing into the bleed chamber 13 via the solution introduction pipe 18, and the flow continues.

While the above operations continue, the storage tank 1
The pressure in 6 gradually increases, and the liquid level in side channel 25 gradually decreases accordingly. When the liquid level becomes lower than one of the liquid level relays 26, the liquid level relay 26 operates, starts the exhaust pump 22, opens the solenoid valve 21, and discharges the non-condensable gas in the bleed tank 16.

The actual evacuation work starts when the exhaust pump 22 is activated and the check pressure relay 29 operates when the suction side of the exhaust pump 22 reaches a predetermined degree of vacuum, opening the solenoid valve 30.

As the exhaust work progresses, the liquid level in the side passage 25 rises, and when it reaches the other liquid level relay 27, the other liquid level relay 27 operates, closing the solenoid valve 21,
The exhaust pump 22 is stopped.

FIG. 3 shows another embodiment of the present invention. In the embodiment shown in FIG. The non-condensable gas is ejected into the opening of the gas-liquid down pipe 14, so that the non-condensable gas is effectively mixed into the solution flowing down inside the gas-liquid down pipe 14.

In this case, the cooling coil 20 is preferably arranged to cool the solution passing through the solution introduction tube 18. Furthermore, if air is extracted from the condenser, a cooling pipe is naturally unnecessary.

The operation of this embodiment is almost the same as that in FIG. 2, so the explanation will be omitted.

The embodiments of the invention described above have the following effects.

(1) When returning the solution from the gas-liquid separator to the absorber, it passes through the riser, so the non-condensable gas is increased to the absorber pressure plus the pressure equivalent to the liquid column up to the top of the riser. The stored air pressure can be taken.

Therefore, the storage pressure of non-condensable gas can be significantly increased, and the storage capacity per volume of the storage tank can be improved.

This also allows the exhaust cycle to be lengthened.

(2) Since the liquid level relay controls the start/stop of the exhaust pump and the opening/closing of the solenoid valve, it is possible to reduce malfunctions, which may result in the risk of exhausting more than necessary, causing refrigerant vapor to be sucked into the exhaust pump, causing oil deterioration, or insufficient exhaust. This can be resolved.

As described above, according to the present invention, when the solution is returned from the gas-liquid separator to the absorber, it is passed through the rising part, so that the pressure equivalent to the column up to the top of the rising part is added to the pressure in the absorber. The storage pressure of the non-condensable gas can be increased to a value of 0.05, thereby significantly increasing the storage pressure of the non-condensable gas. Therefore, the pressure relay or liquid level relay
Since the difference in operating pressure or liquid level between ON and OFF can be made large, detection of exhaust timing is stable, malfunctions are eliminated, and exhaust work can be performed properly.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional automatic air extraction device, FIG. 2 is a system diagram of one embodiment of the present invention, and FIG. 3 is a system diagram showing the main parts of another embodiment of the invention. 1... Evaporator, 2... Absorber, 3... Regenerator,
4... Condenser, 6... Solution pump, 13... Air bleed chamber, 14... Solution downcomer, 15... Gas-liquid separator,
16... Air storage tank, 17... Air extraction pipe, 18...
Solution introduction pipe, 20... Cooling coil, 21... Solenoid valve, 22... Exhaust pump, 24... Solution return pipe,
24a...rising portion, 25...side road, 26,
27...Liquid level relay, 32...Nozzle.

Claims (1)

[Claims] 1 A bleed chamber, a bleed pipe that leads non-condensable gas to the bleed chamber,
A solution introduction pipe that guides a portion of the solution discharged from the solution pump into the bleed chamber, a gas-liquid pipe that lowers the solution from the bleed chamber and transports it to the gas-liquid separator with the non-condensable gas in the bleed chamber mixed in. A downcomer pipe, a gas-liquid separator that is connected to the gas-liquid downcomer pipe and separates the solution and non-condensable gas, an air storage tank that stores the non-condensable gas separated by the gas-liquid separation pipe, and a gas-liquid separator that transfers the solution from the gas-liquid separator to the absorber. The solution return flow path has a valve connected to the air storage tank and a solution return flow path for returning the gas, and the non-condensable gas accumulated in the air storage tank is discharged to the outside of the air storage tank by opening the valve. An air extraction device for an absorption type water chiller/heater, characterized by having an inverted U-shaped rising portion rising from a liquid separator to a predetermined height.