JPS5840458A - Absorption type 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 The present invention relates to an absorption refrigerator that automatically and continuously controls the flow rate of a dilute solution in a circulation system according to load characteristics.

In absorption refrigerators, the amount of heat input is generally controlled according to load characteristics. In this case, if only the amount of heat input is controlled and the amount of dilute solution circulated is not controlled, the amount of dilute solution flowing into the regenerator will be too large or too small, so the refrigerator should be operated under normal conditions. It becomes difficult. Therefore, it is necessary to control the flow rate of the dilute solution in accordance with the control of the amount of heat input, but the conventional method of controlling the circulation flow rate of the dilute solution is to use a fixed orifice.
λ step control or T(1gh/Low 10FF three step control) was common.

However, since the temperature or pressure of the regenerator changes continuously due to heat input control, the conventional method of controlling the flow rate of a dilute solution in stages cannot operate the refrigerator sufficiently efficiently. was difficult.

The present invention was made based on the above-mentioned circumstances,
The purpose is to provide an absorption refrigerator that can continuously control the flow rate of a dilute solution according to the control of the amount of heat input.

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

FIG. 1 is a system diagram showing an embodiment of an absorption refrigerator according to the present invention. In this figure, (1) is a high-temperature regenerator into which a dilute solution is introduced and heated with a burner, (2) is a high-temperature regenerator (3) is a separator that separates the solution heated in 11 into refrigerant vapor and an intermediate concentrated solution. ) is a low temperature regenerator 1, and a separator (
The intermediate concentrated solution separated in step 2) is introduced through the Takamachi heat exchanger (4), where the temperature is lowered by 1 degree due to heat exchange with the dilute solution, and the high temperature refrigerant vapor from the separator (2) is introduced. is heated again. (5)° is a condenser which cools and condenses the refrigerant vapor from the low temperature regenerator (3) into the cooling water flowing through the coil (Sa).

The concentrated solution concentrated in the low-temperature regenerator (3) passes through the low-temperature heat exchanger +61 and is lowered in temperature through heat exchange with the diluted solution, and then is sprayed onto the coil (7a) of the absorber (7). (8) is an evaporator, and cold water from a load (not shown) flows through the coil (ga). Then, the refrigerant condensed in the condenser (5) is sprayed onto the coil (ga), and the refrigerant is spread over the coil (f).
It evaporates by removing the heat of vaporization from the cold water in fa). °The chilled water is therefore cooled and sent to the load. The refrigerant vapor evaporated in the evaporator (8) is absorbed by the concentrated solution in the absorber (7) to form a dilute solution, and this dilute solution is passed through the solution circulation pump 19) to the flow control valve aq and the heat exchanger +41. +61 and is supplied to the high temperature regenerator (1), and the same operation is repeated thereafter.

The flow rate control 4f plays an important role in the present invention, and an example thereof is shown in detail in FIG. In Figure 1, the pipe 0υ is connected to the outlet side of the solution circulation pump (9), and the pipe α2 is connected to the inlet side of the low temperature heat exchanger (6). The pipe a3 is connected to the high-temperature regenerator (1) as shown by the broken line in FIG. 1, and is used to receive the internal pressure of the regenerator (1). This is the a14trs ball receiving chamber, and a receiving board Oe fixed to the bellows fi51 is provided inside. A shaft αη is connected to the pressure receiving plate (II), and is connected to a valve α9 through an orifice 08 provided in the shaft arna pipe fIJ. ■ is a spring.

Next, the operation of the flow rate control valve 0I will be explained with reference to FIG. - No. 31 (a) shows the state of the flow control valve Ql when the operation of the fl refrigerator is stopped, and (b) shows the initial state at the beginning of the operation. Balance of force at this time Id +11
It is expressed in the reverse side of the formula.

AI (PP-PGE) > F3...+11
However, [2] The meaning of each symbol is as follows.

A1: Discharge pressure of bellows (+51 effective area P,: solution circulation pump 19) Paw: Internal pressure of high temperature regenerator (1) F8: Valve (spring load when 19 is closed - In equation (1), the left term is the valve The closing force is , and the crest is the opening force.At the beginning of the operation head, the pump discharge pressure P is received, the pressure receiving plate full K is the closing force of the valve, and the opening force acts on the valve, but the area of the pressure receiving plate (bellows By making the effective area larger than the nozzle opening area J'', a closing force acts on the valve.

As the temperature of the regenerator (1) increases, the regenerator P. F.

will also increase. In equation (1), the occluding force is reduced to the left term. Then, the regenerator pressure becomes equal to the closing force and the opening force. What determines the regenerator pressure at this time is the spring load Fs when the valve is closed, and 198271
The regenerator pressure at a point can be freely determined. In this state: If the regenerative temperature further increases, the closing force decreases,
Equation (1) becomes L of equation (2).

,a,,(p,, -PGE')<FS''...(
2) However, P(4") after the regenerative temperature change rises, the opening force becomes larger than the closing force, and the valve 09 is moved in the opening direction to become the flow control valve (IllI is fc in FIG. 3). The balance of forces at this time is shown in equation (3).

A, (P, -ΔP, -P.F,' ) ” FS-
The dilute solution is circulated into the high-temperature regenerator (1) by the opening of the spring constant valve. Dilute solution circulation and heat input to the regenerator (1)
Rini ↓ Regeneration type temperature # (kogata) becomes a constant value. Due to the stability of the regenerator power, the L valve opening degree is also stabilized.

'If the heat input increases depending on the load characteristics, the regenerator (1
At 1, the heat input increases and the temperature (pressure)
increases. At this time, the flow control valve (I [I FI PG
E increases, the closing force decreases, and the 119id moves in the opening direction (Fig. 3 (dl) L, the dilute solution circulation amount increases.

In other words, by increasing the heat input Q (i
nput) and the amount of dilute solution circulated.

When the amount of heat input (input) decreases, the regenerator temperature (dry force) decreases, and the flow control valve QOI increases the closing force (the third
As shown in Figure (e), the amount of dilute solution circulated decreases.

(Formula 31 r shi S becomes, and further −=:, , −i!= 2. P, −Δ
When P, = P0 and k k are substituted, δ=1-2Po+2PGE1111I+(4). Here, if we ignore the change in the pump discharge pressure at the 4F opening after the valve is opened, considering it to be minute, the result is K2P.

is constant and equation (4) is δ:KP 10K. +1・-+5) GE, and it can be seen that there is a comparative relationship between the valve opening degree δ and the regenerator pressure.

It is well known that there is a proportional relationship between the valve opening degree and the flow rate, and therefore the flow rate and the regenerator pressure have a similar relationship.

As detailed above, according to the present invention, it is possible to adapt to the load characteristics.
When the amount of heat input is controlled by
5 is controlled, and the circulating flow rate of the dilute solution is automatically followed and controlled. Furthermore, as the control signal for s/Jf and quantity control aα, pressure (or temperature) changes inside the refrigerator are used without using a signal for heat input control, so it is rare regardless of the heat input control method. The amount of solution circulation can be controlled.

Therefore, according to the present invention, instead of the conventional step-by-step control using an orifice, the temperature inside the refrigerator can be controlled directly! As an I source, it is possible to automatically and continuously control the dilute solution circulation amount without requiring any other auxiliary driving source, and the operating efficiency of the refrigerator can be greatly improved.

Note that the present invention is not limited to dual-effect absorption refrigerators.

It is also applicable to other absorption refrigerators.

Furthermore, since the present invention uses pressure (temperature) changes inside the refrigerator as a signal as described above, it can be said to be applicable not only to heat input control but also to cooling water characteristics.

It is well known that when the cooling water temperature drops, the temperature of each part inside the refrigerator also drops. As the internal pressure decreases, the possibility of crystallization and the possibility of freezing of the refrigerant in the evaporator increases as the concentration of the concentrated solution increases.

Based on empirical results, it is considered desirable that the dilute solution circulation flow rate at this time does not change significantly.

When considering dilute solution circulation control using a fixed orifice, as the cooling water temperature decreases, the temperature of the high temperature regenerator also decreases, which increases the difference between the pressure of the solution circulation pump and the pressure of the high temperature regenerator. The dilute solution circulation flow rate increases. However, in the flow rate control valve of the present invention, the dilute solution circulation flow rate always corresponds to the regenerator pressure, and no large change in flow rate occurs.

Therefore, not only can the dilute solution circulation flow rate corresponding to heat input i (inpu control) be automatically and continuously controlled, but also the cooling water characteristics, which have been a major problem with absorption chillers, can be controlled. It is possible to respond.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing one embodiment of an absorption chiller according to the present invention, Fig. 2 is a sectional view showing an example of a flow rate control valve used in the present invention, and Fig. 3 is a diagram showing each operation of the present invention. It is an explanatory view showing operation of a flow control valve in a state. +11...High temperature regenerator, (2)...Separator, (3)...
Low temperature regenerator, (5)...condenser, (7)...absorber,'
+81...Evaporator, 19)...Solution circulation pump, 00)
...Flow control valve. Figure 2

Claims (1)

[Claims] The refrigerant that evaporates by removing the heat of vaporization from the load water in the evaporator,
The refrigerant is absorbed into an absorption solution in an absorber to form a dilute solution, and this dilute solution is heated in a regenerator to regenerate the refrigerant and absorption solution using L, and the regenerated refrigerant is supplied to the evaporator. In addition, in an absorption refrigerating machine having a circulation system configured to supply the regenerated absorption solution to the absorber, the circulation system is configured to continuously change the circulation amount of the dilute solution within the circulation system. An absorption refrigerating machine characterized by being equipped with a flow control valve whose opening degree changes depending on pressure or temperature.