JPH0788988B2 - Absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an absorption refrigerating machine, and more particularly to an absorption refrigerating machine in which the chilled water temperature is controlled to always be kept within a temperature setting range regardless of the load. It is about machines.

[Prior Art] An example of a conventional refrigerator of this type is shown in FIG. 3 and FIG. This example is disclosed in Japanese Utility Model Publication No. 61-35894.

In FIG. 3, (1) is a high-temperature regenerator, which has a combustion heating chamber (2) for gas or the like and heats and separates the refrigerant from the dilute liquid.
(3) is a low temperature regenerator for further heating and separating the refrigerant from the regenerator (1), and the refrigerant from both regenerators (1) and (3) is cooled and liquefied by the condenser (4).

The refrigerant from the condenser (4) is sent to the evaporator (5) and is evaporated to cool the water in the cold water pipe (20) to be cold water. On the other hand, the evaporated refrigerant is absorbed by the concentrated liquid in the absorber (6) to become a dilute liquid, and is pumped to the high temperature regenerator (1) again by the solution pump (13). (7) and (8) are low-temperature and high-temperature heat exchangers, which are a refrigerant vapor conduit (9) and a refrigerant liquid downflow pipe (1).
0), a refrigerant circulator (12) having a refrigerant pump (11), a dilute liquid pipe (14) having an absorbing liquid pump (13), and an intermediate liquid pipe (1).
5) and the concentrated liquid pipe (16) are connected to form a refrigeration cycle.

Reference numeral (20) is a chilled water pipe, which is connected to an air conditioner (not shown) for indoor load to cool the room.

A heating amount control valve (17) is attached to the fuel supply pipe (18) to the combustion heating chamber (2). A temperature detector (19) is provided on the cold water outlet side of the cold water pipe (20). (21) is a controller for controlling the refrigeration cycle.

Next, the operation of the above-mentioned conventional device will be described.

The controller (21) takes in the signal from the temperature detector (19) and sets the temperature set by the built-in temperature setter, for example, 15
When the temperature rises above the temperature, the heating amount control valve (17) is opened, fuel supply to the combustion heating chamber (2) is started, and the cold water temperature is controlled within a certain range, for example, within the range of 5 to 15 ° C.

Further, when the cold water temperature drops, that is, when the cold water temperature further drops below the set temperature of 5 ° C., for example, when it reaches 4 ° C., the refrigerant pump (11) is stopped, and when the temperature falls below, for example, 3 ° C. When it becomes, the solution pump (13) is stopped to prevent freezing of cold water.

The above control will be described in detail below with reference to FIGS. 4 (A) to 4 (C).

That is, the heating amount control valve (17) is closed at the point a when the temperature T ₂ = 5 ° C. set by the temperature setting device in the controller (21) is reached when the cold water temperature decreases.

Even after the heating in the high temperature regenerator (1) is stopped, the refrigerant evaporates due to the preheating of the solution, and the refrigerant pump (11) and the absorption liquid pump (13) are also operating, so the inside of the evaporator (5) The evaporation cycle of the refrigerant will continue. Therefore, when the cooling load is small, the cold water outlet temperature further decreases.

On the other hand, when the cold water temperature rises, that is, at the point C when the set temperature T ₁ of the temperature setter reaches 15 ° C., the heating amount control valve (17) is opened and heating of the high temperature regenerator (1) is started.

However, the solution temperature in the refrigeration cycle is low and the solution concentration is low, so that the refrigerant separation is not performed immediately after the start of heating, and after the solution temperature rises, the evaporation capacity in the evaporator (5) becomes maximum. . Therefore, the temperature of the cold water will rise even after the heating control valve (17) is opened. When the indoor cooling load is large, the difference between the set temperature T ₁ and the cold water temperature becomes large.

[Problems to be Solved by the Invention] Since the conventional absorption chiller is configured as described above, a phenomenon occurs in which the cold water temperature becomes lower or higher than the set temperature of the temperature setter depending on the load. . That is, there is a problem that the indoor temperature is also overcooled or overheated, and comfortable air conditioning is not performed.

Therefore, there is a problem that the above problems must be solved.

The present invention has been made to solve the above problems,
An object of the present invention is to obtain an absorption refrigerator in which the room temperature is not overcooled or overheated depending on the load.

[Means for Solving the Problems] In the absorption chiller according to the present invention, the chilled water temperature changes after opening and closing the heating amount control valve according to a preset program from the chilled water temperature and the chilled water temperature change rate by the controller. Is calculated and estimated, the opening / closing temperature of the heating amount control valve where the cold water temperature stays within the set range is calculated, and the heating amount control valve is opened / closed.

That is, when the change rate of the cold water temperature is large, the controller “opens” the heat source fluid control valve before reaching the upper limit value, that is, at the cold water temperature lower than the upper limit value when the cold water temperature rises.
It sends a signal to turn on. Also, the controller is
When the chilled water temperature decreases, when the rate of change of the chilled water temperature is large, a signal for closing the heat source fluid control valve is issued before the lower limit value is reached, that is, at the chilled water temperature higher than the lower limit value.

[Operation] In the controller of the present invention, the cold water temperature and the rate of change of the cold water temperature do not cause the cold water temperature to exceed the set temperature even after the heating amount control valve is opened.
The control temperature closest to the set temperature is calculated, and the heating amount control valve is opened / closed at this control temperature.

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

1 and 2 illustrate one embodiment of the present invention. In each drawing, the same parts as those in FIG. 3 or 4 are designated by the same reference numerals and the description thereof will be omitted.

As is clear from comparison between FIG. 1 and FIG. 3, the structure of each part of the refrigerator is the same, but the control method by the controller (31) is completely different.

That is, coolant outlet temperature in the case of performing the coolant outlet temperature control in FIG. 2 (A) ~ (C) present method, is a diagram showing a state and cooling capacity of the heating control valves, T _1, T in FIG. ₂ indicates the set temperature, and T ₁₁ and T ₂₂ indicate the temperatures at which the heating amount control valve (17) is opened and closed.

The controller (31) has a temperature (for example, 5 ° C when the temperature drops and 15 ° C when the temperature rises) set by a built-in temperature setting device (not shown),
Based on the detection signal from the temperature detector (19), the chilled water temperature change rate (for example, if the chilled water temperature decreases by 1 deg per minute, the temperature change rate will be 1/60 (deg / sec)) At the same time, a signal for opening and closing the heating amount control valve (17) (closing when the chilled water temperature drops) is emitted from the current chilled water temperature according to a preset program.

In addition, when the temperature of the cold water decreases, the program is higher than the set temperature (5 ° C.) (for example, 6
On the contrary, if the temperature change rate is small, the heating amount control valve (17) is closed at a temperature close to the set temperature (for example, 5.5 ° C.).

In addition, the program closes the heating amount control valve (17) and then operates the refrigerant pump (11) and the absorption liquid pump (13),
Even if the cold water temperature drops, the open / close temperature of the heating control valve (17) should be calculated considering the performance of the refrigerator so that it does not drop below the temperature (5 ° C) set by the temperature setting device. It is set.

That is, when the cold water temperature decreases, the rate of change of the cold water temperature (ΔT ₁ / Δ
The temperature (T ₂₂ ) at which the heating amount control valve (17) is closed according to a preset program from t ₁ ) and the current cold water temperature.
When the chilled water temperature reaches T ₂₂ , the heating amount control valve (1
Close 7) and stop heating the high temperature regenerator (1).

However, since the refrigerant pump (11) and the absorption liquid pump (13) are operating, the cold water temperature further decreases, but the heating amount control valve (17) is kept so that the cold water temperature does not fall below the set temperature T _2.
The closing temperature T _{22 of} is determined.

The same applies when the cold water temperature rises, and the rate of change of the cold water temperature (ΔT ₂ / Δt
The open temperature T ₁₁ of the heating amount control valve (17) is calculated from ₂ ) and the cold water temperature, and heating is restarted.

However, since the cooling capacity rises slowly, the cold water temperature rises but does not exceed the set temperature T ₁ .

As described above, it is possible to obtain the absorption refrigerating machine in which the room temperature is neither overcooled nor overheated.

Although the cold water temperature (19) is attached to the cold water outlet side in the above embodiment, it may be provided to the cold water inlet side.

[Effects of the Invention] As described above, according to the present invention, the opening / closing temperature of the fuel supply valve to the high temperature regenerator is changed from the set temperature within the set temperature range from the change rate between the cold water temperature and the change rate of the cold water temperature. ,
Due to the configuration that the temperature is farther away, the cold water temperature after opening and closing the fuel supply valve does not exceed the set temperature, and is always controlled within the set temperature range regardless of load changes, and stable cold water temperature is supplied. You can

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an absorption refrigerator according to the present invention, FIG.
FIG. 3 is a diagram showing a temperature change during chilled water temperature control according to the present invention, FIG. 3 is a schematic configuration diagram of a conventional absorption chiller, and FIG. 4 is a diagram showing a temperature change during conventional chilled water temperature control. is there. In the figure, (1) is a high temperature regenerator, (2) is a combustion heating chamber,
(3) is a low temperature regenerator, (4) is a condenser, (5) is an evaporator, (6) is an absorber, (7) is a low temperature heat exchanger, (8) is a high temperature heat exchanger, and (9). Is a refrigerant vapor conduit, (10) is a refrigerant liquid flow down pipe, (11) is a refrigerant pump, (12) is a refrigerant circulation path, and (1
3) is an absorption liquid pump, (14) is a dilute liquid pipe, (15) is an intermediate liquid pipe, (16) is a concentrated liquid pipe, (17) is a heating control valve, (18) is a fuel supply pipe, (19) ) Is a temperature sensor, (20) is a cold water pipe,
(21) and (31) are controllers. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A regenerator, a condenser, an evaporator, an absorber, a refrigerant pump, an absorption liquid pump, etc. are connected by piping to form a circulation path for the refrigerant and the absorption liquid, and control is provided for the heat source fluid supply path of the regenerator. An absorption refrigerator having a valve is provided with a controller electrically connected to a temperature detector and a heat source fluid control valve provided in a chilled water pipe section of the evaporator, and the controller is a chilled water temperature setting device. By using the upper limit value or lower limit value of the cold water temperature set by, and each data of the change rate of the cold water temperature and the cold water temperature, when the change rate of the cold water temperature is large when the cold water temperature rises, the upper limit value of the cold water temperature At a lower cold water temperature, a signal for opening the heat source fluid control valve is issued, and when the cold water temperature drops, if the rate of change of the cold water temperature is large, at the cold water temperature higher than the lower limit value of the cold water temperature. , The heat source fluid control valve An absorption chiller characterized by being configured to emit a signal to "close".