JPS5872855A - Absorption type air conditioner - 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 relates to an absorption air conditioner used in an air conditioner or the like.

Conventional absorption air conditioners of this type use kettle-type boilers, furnace water tube boilers, etc. for their generators, so they have a large amount of stored liquid, and there is a risk that the refrigeration capacity will be slow to rise at the time of start-up. . Furthermore, at the start of operation, the temperature and pressure of the generator are low and the differential pressure between the high pressure side and the low pressure side is insufficient, so liquid returns from the generator to the absorber is poor.

For this reason, conventional methods have been to increase the capacity of the liquid tank and generator connected to the absorber to prevent cavitation from occurring due to a drop in the liquid level in the circulation pump connected to the liquid tank, and to temporarily supply solution to the generator. In addition to storing a large amount of water, control measures were taken to adjust the pressure reducing valve to improve drainage.

As mentioned above, increase the valley of the liquid tank and generator,
Furthermore, if the amount of sealed solution is increased, there are disadvantages such as poor load response due to an increase in heat capacity, and a long time required from startup to change of refrigeration capacity.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, to quickly build up the refrigerating capacity at the start of operation, and to prevent the occurrence of cavitation in the circulation pump. The gas-liquid separator and the liquid tank are connected to a bypass return pipe, and the bypass return pipe is provided with a tilt control valve that opens and closes depending on the liquid level of the liquid tank. It is characterized by this.

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

In FIG. 1, 1 is an evaporator, 2 is an absorber, 3 is a liquid tank, 4 is a circulation pump, 5 is a heat exchanger, 6 is a through-boiler type heater 6A, a combustor 6B, and a gas-liquid separator 6C. 7 is a condenser, and these devices 1 to 7 are operably connected by piping. 8 is an expansion valve provided in a pipe 9 connecting the evaporator 1 and the condenser 7.

11 is a throttle provided in the main return pipe 12 that communicates the gas-liquid separator 6C with the pipe 10 that connects the evaporator 1 and absorber 2; 13 is a throttle provided in the gas-liquid separator 6C; A float valve 14 is provided at one end 12a of the main return pipe 12 so as to open when the liquid level rises, and 14 is a bypass return valve that connects the gas-liquid separator 6C and the liquid tank 3. A float valve 15 that opens when the liquid level of the liquid tank 3 falls is provided in the opening on the liquid tank 3 side.

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

The solution containing the refrigerant in the liquid tank 3 is sucked and pressurized by the circulation pump 4, and then introduced into the heater 6A of the generator 6 via the heat exchanger 5, where it is heated by the combustion gas generated from the burner 6B. It is introduced into the gas-liquid separator 6C while being heated. The refrigerant vapor separated by the gas-liquid separator 6C is introduced into the condenser 7, where it is cooled, condensed, and liquefied.Then, the pressure is reduced by the expansion valve 8, and then introduced into the evaporator 1, where it is evaporated and vaporized. do. At this time, cooling and freezing effects are performed by the latent heat of vaporization.

On the other hand, the solution in which all the refrigerant vapor is generated in the gas-liquid separator 6C is transferred to the float valve 13. Main return pipe 12. Heat exchanger 5 and throttle 11
The liquid is then introduced into the absorber 2, where it is cooled while absorbing the refrigerant vapor from the evaporator 1, and then returned to the liquid tank 3.

At the start of operation, if the differential pressure between the pressure control side and the low pressure side is not large enough, the return of liquid from the bubble separator 6C of the generator 6 to the absorber 2 is poor, so that the gas-liquid separator 6C The liquid level rises. In addition, since the temperature of the solution in the heater 6A and the heat exchanger 5 is low, the flow state of the solution does not become a gas-liquid two-phase state, but flows in a full liquid state, and the amount of retained liquid increases.
Since the amount of liquid in the liquid tank 3 is relatively insufficient, the liquid level decreases.

When the liquid level in the liquid tank 3 drops at a certain point near the limit for absorbing refrigerant vapor from the circulation pump 4, the float valve 15 of the liquid tank 3 opens.

For this reason, the solution in the gas-liquid separator 6C is returned to the liquid tank 3 via the liquid return pipe 14 and the 70-meter square 15. In response to the decrease in the liquid level in the liquid tank 3, the crab
Since the solution is supplied from the gas-liquid separator 6C to the liquid tank 3, it is possible to prevent cavitation from occurring due to idle running of the circulation pump 4 and suction of refrigerant vapor.

Next, we will consider the heat capacity related to the delay in startup time of absorption air conditioners.

(1) Generate the refrigerant of the sealed solution, let the solution amount be G, #summer clothes from the initial state be Δξ, and the latent heat of vaporization of the refrigerant be i.
The above Q is expressed by the following formula.

ΣQII−GJ・Δξj・1 ・・・・・・・・・
(1)! (11) Q2 for increasing the temperature of the sealed solution
．． The temperature difference from the initial state is Δt, the specific gravity of the solution is k Cp,
Then, Q2 is expressed by the following formula.

ΣQzj=G1・C1゜j・Δ1.・・・・・・
(2) (iii) As in the above, if the amount of heat to raise the temperature level of the component equipment at each location is Q, then Q3 is expressed by the following equation.

ΣQ31=GJ−Cpj・Δ1.・・・・・・
...(3) flJ, t In the combination of refrigerant and absorbent of Haflon R-22 and tetraethylene glycol dimethyl ether, on the generator (Δt x 100r), that is, on the solution side, Δξ-10%, CPPO25K (Il
l/~・ki, i ki 45K (2f/Kg, so
Qs +Q! = G (0,10X 45+0.5X
100)-GX55 (1(m) Also, for the constituent materials, Qs'-Gp (0゜lX100) = 10XGρ(Km
), for the same weight increase, an increase in the encapsulated solution has a five times greater effect on the heat capacity than an increase in the weight of the constituent materials. Therefore, reducing the heat capacity is
This is very effective in speeding up the start-up time of refrigerating capacity in absorption air conditioners that can only be heated in a limited number of pre-installed units.

In addition, the ratio and capacity of an air conditioner are closely related to two factors: 7M degrees and the balance of refrigerant number in the solution, and the temperature is as shown in equations (1) to (3) above. .

On the other hand, regarding the balance of the refrigerant concentration in the solution, the capacity of the circulation pump (Jp + Liquid Doll G sealed in the cycle).

There is a first-order lag relationship between That is, assuming that the time constant is τ, this τ is as follows.

τ”” G −/ G p ・・・・・・
(4) Therefore, for a JJ pump of the same capacity (+t#), reducing the amount of sealed molten e as much as possible will improve responsiveness.

FIG. 2 shows another embodiment in which a drop in the liquid level in the liquid tank 3 is detected by a liquid level detector 17, and this detection signal opens a solenoid valve 16 provided in a bypass return pipe 14. This is how it was done. Moreover, in order to prevent flapping when the solenoid valve 16 opens and closes, the delay circuit 18 is provided.
The solenoid valve 16 is configured to open for a certain period of time with one detection signal. The rest of the configuration is the same as the embodiment shown in FIG. 1, so the explanation will be omitted.

Although cooling was explained in the above implementation night 0, the same applies to heating or a heat pump heating cycle, so the explanation will be omitted.

As explained above, according to the present invention, by reducing the amount of liquid in the liquid tank, the occurrence of cavitation can be prevented, and the amount of filled liquid can be reduced to improve responsiveness. p, and the rise of the refrigerating capacity at the time of starting the exercise can be accelerated.

[Brief explanation of the drawing]

FIGS. 1 and 2 are system diagrams showing an embodiment of an absorption air conditioner according to the present invention. 2... Absorber, 3... Liquid tank, 6... Generator,
6A... Once-through boiler type heater, 6C... Gas-liquid separator, 14... Bypass return pipe, 15... Control valve. Agent Patent Attorney Toshiyuki Usuda Punishment 1 Figure Z

Claims (1)

[Claims] In an absorption air conditioner in which an evaporator, an absorber, a liquid tank, a circulation pump, a heat exchanger, a generator, and a condenser are all operably connected, the generator is combined into a once-through boiler type heater and a gas-liquid separator. Connect this gas-liquid separator and the mJ We liquid tank to a bypass return pipe, and then connect this gas-liquid separator to the bypass return pipe! ll
An absorption type air conditioner characterized in that a valve is provided which opens depending on the liquid level in the liquid tank.