JPS6038564A - Method of controlling absorption 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 a method for controlling the capacity of an absorption refrigerator, which controls the temperature of chilled water and adjusts the temperature of cooling air by operating a heat source control valve.

Conventionally, in the case of a cooling system for air conditioning, the capacity of an absorption chiller is controlled by fully operating the heat source control valve so as to keep the chilled water temperature approximately constant at t''!
The air conditioning system mixes the cold water returning from the room with the cold water from the refrigerator, adjusts the temperature, and sends it to the room to control the room temperature.

However, in such conventional methods, depending on the operating conditions of the air conditioning system, the temperature of the chilled water sent by the refrigerator may vary depending on the operating conditions of the air conditioning system.
The temperature was lower than that required by the room, and the elevated temperature was mixed with the cold water returned from the room to adjust the temperature to the room's temperature. In general, the efficiency of an absorption chiller is greatly affected by the temperature of the chilled water; for example, increasing the temperature of the chilled water by 1° C. will increase the efficiency by 2 to 3%. That is, in the conventional method, producing cold water at a lower temperature than necessary leads to a decrease in efficiency and wastes energy.

The present invention eliminates the above-mentioned drawbacks of the conventional method and reduces the temperature of cold water below the temperature required by the room.
To provide a control method for an absorption chiller that can save energy without reducing efficiency by operating the absorption chiller while keeping the chilled water temperature as high as possible under conditions where the room temperature is within an allowable range. This is the purpose.

The present invention provides a method for controlling an absorption refrigerator in which a heat source control mechanism is operated by an operation signal from a control mechanism to control chilled water temperature and adjust cooling air temperature, wherein the control mechanism comprises a
A method for controlling an absorption refrigerator, comprising receiving a signal and a signal b, and outputting the operation signal based on the signal a and signal b.

Signal a... A signal that detects the chilled water temperature and is output from the chilled water temperature control function so that the chilled water temperature Tw becomes a predetermined target value Two. Signal... The room temperature is detected and the room temperature TR becomes a predetermined target value. T
This is a signal output from the room temperature control function so that the temperature is RO.

Embodiments of the present invention will be described using the drawings.

In Figure 1, A is an absorber, E is an evaporator, GH is a high temperature generator, GL is a low temperature generator, C is a condenser, XH is a high temperature solution heat exchanger, XL is a low temperature solution heat exchanger, and SP is a solution heat exchanger. The pump and RP are refrigerant pumps, and these devices are connected to form a solution path and a refrigerant path to form a refrigeration cycle.

1 is a burner for heating the solution in the high temperature generator GH; 2
is a heat source control valve as a heat source control mechanism that adjusts the flow rate of fuel for the burner 1 to control the amount of heating. 6 is cold water pipe,
4 is a temperature detector that detects the cold water outlet temperature. The detection signal is sent to the chilled water temperature controller 5 as a chilled water temperature control function, and further sent to the control mechanism 6 as an a signal.

Reference numeral 7 indicates a room whose room temperature is to be controlled, and the detection signal of the room temperature detected by the temperature detector 8 is sent to the room temperature controller 9 as a room temperature control function, and further sent to the control mechanism 6 as b (8).

As described later, the control mechanism 6 selects the a signal or the b signal depending on conditions, and outputs the following C operation signal based on the selected signal.

That is, when the a signal is selected, the C operation signal is output to operate the heat source control valve 2 so that the chilled water temperature Tw becomes a predetermined target value Two (error tolerance range Two±ΔTw), and the chilled water temperature is adjusted. It is designed to control Tw. Also, b
When the signal is selected, the room temperature TR reaches the predetermined target value T.
C so that RO (error tolerance range TRO±ΔTw)
It outputs an operation signal and operates the heat source control valve 2 to control the room temperature TR.

The above-mentioned ΔTw and ΔTR are error tolerance ranges for the target values Two and TRO of the cold water temperature Tw and room temperature TR, and the lower limits of these tolerance ranges are respectively referred to as follows.

TWL: Minimum allowable cold water temperature - Two - ΔTw TRL: Minimum allowable room temperature = Tpo - ΔTR Next, some examples regarding the selection of the a signal and b signal in the control mechanism 6 and the C operation signal based on the selected signal I will explain about it. These signals may be analog values such as current values, voltage values, oil pressure values, or air pressure values, or digital values such as pulse signals.

FIG. 2 shows the control state of the first embodiment.

In this control, in the state where TvV≧TwL and TR≧'1'RL, the a signal or the b signal is continuously selected and control is performed, but when TV<TWL from that state...a Select signal When TR<TRL・
...The b signal is selected.

For example, assume that the system is initially in the state of point P in the figure, and that the chilled water temperature is controlled by the a signal at that time. Assume that as a result of this cold water temperature control, the cold water temperature Tw decreases, but the room temperature TR also decreases and reaches 21 points. At these 21 points, the cold water conductivity Tw is Tw > TWL, so it continues to be a.
The signal causes the cold water temperature Tw to further decrease, and accordingly, the room temperature TR also begins to decrease. And room temperature TR is TR<TRI.

When this happens, the control mechanism 6 changes the b signal and switches to room temperature control, so that the room temperature does not fall below TR1.

At this time, the cold water temperature Tw is higher than TWL, but since the signal has already been switched to the b signal, the cold water temperature control is not performed and the high cold water temperature state is maintained. That is, it is possible to maintain the westernmost cold water temperature in the range of cold water temperatures required to maintain the predetermined room temperature at the lowest level. Therefore, while keeping the room temperature TR at a predetermined temperature, the cold water temperature can be maintained so as to obtain maximum efficiency.

Further, it is assumed that the state at point Q in the figure is initially established, and that room temperature control is being performed using the b signal at that time.

It is assumed that due to this room temperature control, the room temperature TR decreases together with the cold water temperature Tw and reaches 91 points. At this 91 point, the room temperature TR1i: Ti1l > TRL, so the b signal continues to cause the cold water temperature Tw and the room temperature TR to further decrease. When the chilled water temperature Tw becomes Tw<Twl, the controller [6 selects the j2a signal and switches to chilled water temperature control, and the control is performed so that the chilled water temperature Tw does not fall below Twb. be exposed.

Tw r Tn does not fall from the position of point P or point Q75
When the ib state changes, if the signal before crossing the horizontal line of TR=Tnb is the b signal, then TR<
Even when TRL is reached, the b signal is still selected.

Also, ']'W = Two, the signal power E B before crossing the line (if it is a word, Tw < T
(2) Even when the signal becomes 1, the a signal is still selected.

In this way, if control is performed using only one of the a signal and b4F without any chip selection, for example, if only the chilled water temperature is controlled by the a signal, the control trajectory will be R1-D-R2
During D-R2, the room is cooled more than necessary, resulting in wasted labor and effort.If only the b signal is used to control the room temperature, the control trajectory becomes Wl-D-W2. D-
During W2, the cold water temperature Tw drops more than necessary, leading to a corresponding drop in efficiency and energy loss.

On the other hand, the control trajectory according to this embodiment is R+D-Wl
Both the room temperature TRI and the cold water temperature Tw do not drop too much unnecessarily, improving efficiency and saving energy.

FIG. 3 shows the flow of control signals in the second embodiment. The control mechanism 6 compares the a signal and the b signal, and selects the signal that reduces the opening degree of the heat source control valve 20 and further reduces the amount of heat from the heat source. In this way, it is possible to prevent energy loss from lowering the cold water temperature TW+room temperature TR more than necessary.

The above-mentioned a signal or b signal may use the temperature difference from the target value. That is, a signal - DTw = Tw Tw.

It is also possible to use D Tw + D Tn, where b signal - DTR = TRTRO, as the a signal and b signal, and select the signal with the smaller value of both signals.

Also, by multiplying both by their respective ratios m and n, mII
DTw and n*DTR may be compared. In the case of proportional control, even if the proportional constant of the proportional band is different between chilled water temperature control and room temperature control, this m11
It is possible to compare the size by selecting an appropriate value.

These signals may be digitally converted signals suitable for arithmetic processing.

FIGS. 4(a), (b), and (c) show the third embodiment, in which the signal is selected based on the room temperature TR. If TR≧TRL, the tfa signal is selected, and the TR When the signal becomes <, select the change to the b signal.

The a signal and the b signal are selected under the following conditions. Such selection makes it possible to maintain the cold water temperature Tw as high as possible to the extent necessary to obtain the predetermined room temperature TR, and to prevent the cold water temperature Tw from lowering more than necessary and resulting in a decrease in efficiency.

In FIG. 4(a), the control mechanism 6 is a thermostat 11 which is activated by a signal from a temperature detector 10 that detects the room temperature TR. When TR≧TRL, signal a is selected, and TR< When TRL is reached, the b signal is selected and the heat source control valve 2 is controlled.

FIG. 4(b) shows the indoor temperature controller 9 and the thermostat 11.
is included. FIG. 4(c) shows the chilled water temperature controller 5. Indoor temperature controller 9 and thermostat 11
are integrated into one, or processes corresponding to these sequence functions are integrated as an arithmetic system.

FIGS. 5(a), (b), (c), and (d) show a fourth embodiment in which the a signal and the b signal are switched based on the room temperature and the cold water temperature, and the signal This prevents hunting caused by too many switchings.

FIG. 5(a) shows a single controller (chilled water temperature controller 5,
The room temperature controller 9) and single thermostats (cold water thermostat 12, room temperature thermostat 11) are combined to switch in a relay sequence as shown in FIG. 5(b).

First, when Tw < TwL, the relay Xw is excited, so the signal a from the chilled water temperature controller 5 is output regardless of the room temperature. Next, Tw≧TwL and TR<TRL
In the case of , relay Xw is de-energized and relay XR is energized.

Therefore, the b signal from the indoor temperature controller 9 is output.

From the state of Tw≧TWL and TR<TRI, 'rw≧
When the state shifts to TwI and TR≧TRL, the b signal continues to be output because relay XR is self-holding.

On the other hand, from the state of TW<TWL, Tw≧TWL and TR≧T
When the state shifts to RL, relay XR is de-energized, so the a signal continues to be output.

FIG. 5(C) shows a system in which a cold water temperature controller 5, a cold water detection thermostat 12, and an indoor temperature controller 9 and a room temperature thermostat 11 are integrated.

FIG. 5(d) shows a system in which cold water, indoor temperature controllers 5 and 9, and thermostats 11 and 12 are all integrated into one unit.

The above can be applied even if there are multiple refrigerators or six rooms. If there are multiple rooms, the representative room temperature (temperature of the afterglow room or average temperature of each room) may be used as the room temperature.

According to the present invention, the temperature of the chilled water can be kept high under conditions where the room temperature is within the permissible range without lowering the temperature below the temperature required to maintain the room temperature at a predetermined temperature, and the temperature of the chilled water can be kept high under conditions where the room temperature is within the permissible range. It is possible to provide a control method for an absorption refrigerating machine that can save energy without causing a decrease in energy consumption, and it is possible to achieve an extremely effective effect in terms of practical energy saving.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention; FIG. 1 is a flow diagram of an absorption refrigerator, FIG. 2 is a graph showing the control state of one embodiment, and FIGS. 3 and 4 (a). , (b). (C), Figures 5(a), (c), and (d) are system diagrams of different embodiments, respectively, and Figure 5(b) is the same figure (a).
FIG. DESCRIPTION OF SYMBOLS 1...Burner, 2...Heat source control valve, 6...Cold water pipe, 4...Temperature detector, 5...Cold water temperature controller, 6...
...Control mechanism, 7...Room, 8...Temperature detector, 9
...Indoor temperature controller, 10...Temperature detector, 11.
...Thermostat, 12...Thermostat. Patent Applicant Ebara Corporation Patent Attorney Masashi Takagi Sen Yuma 1) Twisting Takao Maruyama Room 2 Figure 3 Figure 4 (α) (b) (c) 12 No. 5 (C) (b) (d)

Claims (1)

[Claims] 1. A method for controlling an absorption refrigerator in which a heat source control mechanism is operated in response to an operation signal from a control mechanism to control chilled water temperature and adjust cooling air temperature, wherein the control mechanism comprises: like a
A method for controlling an absorption refrigerator, comprising receiving a signal and a signal b, and outputting the operation signal based on the signal a and signal b. Signal a... A signal that detects the chilled water temperature and outputs from the chilled water temperature control function so that the chilled water temperature Tw becomes a predetermined target value T'wo. Target value T
Signal 2 output from the room temperature control function so that RO The method described in section. [Conditions] Prisoner When Tw<TWL...select a signal03)
When TR<TnL...select the b signal. However, TWL: Minimum allowable cold water temperature"' Two-ΔTw ΔTw' Tolerable error width TRL: Minimum allowable room temperature = TRO-ΔTR ΔTR: Tolerable error width 6, the above operation signal , the method according to claim 1, wherein a signal that makes the degree of opening of the heat source control valve smaller is selected from the a signal or the b signal and is output based on the selected signal. 4. The method according to claim 1, wherein the operation signal is output based on a signal selected from the a signal or the b signal under the following conditions. [Condition] (A) If Tn≧TRL, select signal a. (B) When TR<TRL, select signal to change. 5. The operation signal is selected from the a signal or b signal according to the following conditions. The method according to claim 1, which is output based on the selected signal. [Conditions] When Tw < TWL, select signal a. (B When Tw≧TWL and TR < TRL, select signal b. (CJ When Tw≧TWJ and Trt≧TRL, the previous signal remains as it is.