JPH0718615B2 - Double-effect absorption chiller / heater controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an improvement of a control device for adjusting the heating amount of a double-effect absorption cold / hot water machine of simultaneous cold / hot water supply type.

(B) Conventional technology In the double-effect absorption chiller / heater that simultaneously supplies cold / hot water,
Heat quantity control for obtaining a cold water output corresponding to the cold water load and a hot water output corresponding to the hot water load. In other words, it is necessary to perform heat input control for driving the absorption chiller-heater.

As a conventional technique for controlling the heating amount, for example, as disclosed in Japanese Patent Publication No. 52-584, a cold water load detector that detects a difference in cold water inlet / outlet temperature determines the size of the cold water load, and the cold water load is large. Sometime, the amount of heating is adjusted by the signal of the cold water outlet temperature detector, while the amount of heating is adjusted by the signal of the hot water outlet temperature detector when the cold water load is small. Further, as another conventional technique, for example, as seen in JP-A-55-96877,
The cooling water outlet temperature detector determines the cooling load, and the hot water outlet temperature detector determines the heating load.The ratio of the partial load on the cooling side to the total load (hereinafter referred to as the cooling load ratio) is a predetermined value [ 95%] or more, or the ratio of the partial load on the heating side to the total load (hereinafter referred to as the heating load ratio) is less than or equal to the lower limit setting value [20%] and the cooling load ratio is the lower limit setting value [20%]. If the above is the case, the heating amount adjustment by the signal from the cold water outlet temperature detector, that is, the cooling main control is performed, and conversely, if the heating load ratio is a predetermined value or more, or the cooling load ratio is less than or equal to the lower limit set value. When the heating load ratio is equal to or higher than the lower limit set value, the heating amount adjustment, that is, the heating main control is performed by the signal from the hot water outlet temperature detector, and both the cooling load ratio and the heating load ratio are within the predetermined range. In the case of [20% to 95%], that is, in the neutral region, the cooling main control is performed when shifting from the cooling main control region to the neutral region, while the cooling main control is performed when shifting from the heating main control region to the neutral region. Things have been proposed.

(C) Problems to be Solved by the Invention In the conventional case such as the former case described above, there is an advantage that the control signal for heating amount adjustment can be easily switched, but the determination for this switching is made. Since it depends only on the comparison of the cold water load, that is, because the size of the hot water load is not the target of discrimination, for example, when the hot water load changes without changing the cold water load, the amount of heating is temporarily changed. The excess and deficiency of the heating amount cannot be resolved until the excess and deficiency occur and the cold water outlet temperature changes due to the effect.
There is a problem that control followability and accuracy are lacking.

On the other hand, in the latter type such as the conventional one, the switching of the control signal for adjusting the heating amount is performed by both the size comparison of the cooling load and the size comparison of the heating load.
Compared with the former, there is an advantage that the heating amount control with respect to the heating and cooling load can be performed more accurately, but on the other hand, there is a problem that a complicated, highly accurate and expensive control device is required because there are various types of discrimination. In addition, for example, when there are cooling and heating loads near the boundary between the neutral region and the region for main control of cooling and heating, the main control can be switched by a slight change in these loads [JP-A-2006-29242].
As shown in FIG. 3 and FIG. 2 of JP-A-55-96877], the heating amount may be adjusted more than the actual load change, and a complicated, expensive and highly accurate control device is used. Nevertheless, depending on the case, there is a problem that the heating amount control with respect to the cooling and heating load lacks accuracy.

In view of the problems of these conventional ones, the present invention can more accurately control the heating amount for cold / hot water load as compared to the conventional ones such as the former, and is simpler than the conventional ones like the latter. It is an object of the present invention to provide a controller for a double-effect absorption water heater that simultaneously supplies cold and hot water and that can perform various heating amount controls.

(D) Means for Solving the Problems The present invention provides means for solving the above problems when the cold water outlet temperature is equal to or lower than the lower limit set value and the hot water outlet temperature is equal to or lower than the upper limit set value. While adjusting the heating amount according to the hot water outlet temperature by distinguishing between the two, in other cases, it is configured with a controller for a double-effect absorption cold water heater with cold / hot water simultaneous supply that adjusts the heating amount according to the cold water outlet temperature. is there.

(E) Action The control device of the present invention, in other words, only when the cold water load is small and the cold water outlet temperature is below the lower limit set value and the hot water load is large and the hot water outlet temperature is below the upper limit set value, in other words, Only when the cooling load is small and the chilled water output is excessive, and the heating load is large and the hot water output is insufficient, the determination is made to adjust the heating amount according to the heating load, that is, the hot water load. The function [action] is performed, and in other cases, it is discriminated to adjust the heating amount according to the cooling load, that is, the cold water load.

As described above, in the control device of the present invention, the size of the cold water load is compared with the size of the hot water load to determine which of the hot and cold water outlet temperatures is used for heating. The accuracy of the heating amount control is improved as compared with the conventional one in which the above determination is made only by the above. Further, since the above-mentioned discrimination is only two types, the heating amount can be easily adjusted by a simple and inexpensive device compared to the conventional one in which the discrimination is diverse.

(F) Embodiment FIG. 1 is a schematic configuration explanatory view showing an embodiment of a control device for a double-effect absorption chiller-heater according to the present invention. In FIG. 1, (1) is a high temperature generator, (2) is a low temperature generator,
(3) is a condenser, (4) is an evaporator, (5) is an absorber,
(6) and (7) are low temperature and high temperature solution heat exchangers,
(P _R ) is a refrigerant liquid pump, (P _A ) is an absorption liquid pump, and (8) is a water heater attached to the high temperature generator (1). ), (10), a pipe (11) through which the refrigerant liquid flows down, a pipe (12) through which the refrigerant liquid flows back,
(13), the pipes (14) and (15) through which the absorption liquid is sent, and the pipes (16), (17), (18), and (19) through which the absorption liquid flows to connect the same refrigerant [water] ] And the absorption liquid [aqueous solution of lithium bromide], and the high temperature generator (1) and the water heater (8) are connected to a pipe (20) through which a refrigerant vapor flows and a pipe (21) through which a refrigerant drain flows. ) Are connected to form a refrigerant circulation path similar to that of the conventional machine.

(22) is the combustion heating chamber of the high temperature generator (1), (23), (2
3) ... is a pipe through which combustion gas flows, (24) is a heater for the low temperature generator (2), (25) is a cooler built in the condenser (3), and (26) is built in the evaporator (4). Is a cooler built in the absorber (5), and (28) is a heat exchanger for hot water. Also, (B) is a burner, and (2
9) and (30) are heat exchange units on the cold water load side and the hot water load side, respectively.

The heat exchange unit (29) and the water cooler (26) on the cold water load side are connected to the pipe (31) and the pipe (32) with the pump (P _c ).
A cold water circulation path is formed by connecting the hot water load side heat exchange unit (30) and the hot water heat exchanger (28) to the pipe (3
Connecting at the hot water circulation path is constituted by 3) and a pump (P _H) with a tube (34). In addition, the cooler (27), (2
5) is connected in series by pipes (35), (36), (37) to form a cooling water flow path. Moreover, (38) is a conduit for guiding fuel to the burner (B). The pumps (P _c ) and (P _H ) can change the discharge amount.

(Stc ₁ ), (Stc ₂ ), (St _c ) are the cold water outlet temperature sensors provided in the pipe (32), (Sth ₁ ), (Sth ₂ ), (St _c ).
h) is a hot water outlet temperature sensor provided in each pipe (34), and (V _F ) is a fuel control valve provided in the pipe line (38). Note that (V _R ), (V _A ), and (V _H ) are the control valve for the refrigerant, the control valve for the absorbing liquid, and the control valve for the refrigerant drain provided in the pipes (10), (15), and (21), respectively. It is a control valve.

(Tset) is a temperature setting device for setting the upper limit value Thc lower limit T _cc and hot water outlet temperature of the coolant outlet temperature, (TC) temperature setting device (Tset), the hot water outlet temperature sensor (Sth _2), chilled water outlet A temperature comparator that compares the temperature sensed by these sensors with the upper and lower limits, while receiving a signal from the temperature sensor (Stc ₂ ), and (C) adjusts the opening of the fuel control valve (V _F ). The controller (SC) receives the discrimination signal from the temperature comparator (TC) and sends a signal from the cold water outlet temperature sensor (Stc ₁ ) or hot water outlet temperature sensor (Sth ₁ ) to the controller (C). Is.

The temperature comparator (TC) is a cold water outlet temperature sensor (St
If the temperature condition in which the sensed temperature Tcx of c ₂ ) is less than or equal to the lower limit value Tcc and the sensed temperature Thx of the hot water outlet temperature sensor (Sth ₂ ) is less than or equal to the upper limit value Thc, a signal is output by the determination signal in this case. Switch the connection of the switch (SC) to the H side. On the other hand, under the conditions other than the above temperature conditions, as shown in FIG. 1, it is connected to the C side.

That is, the connection of the signal switch is as shown in the table below.

The fuel control valve (V _F) is the cold water outlet temperature sensor (St
The proportional control is performed via the controller (C) by the signal of either c ₁ ) or the hot water outlet temperature sensor (Sth ₁ ). The maximum temperature of the controller proportional band of coolant outlet temperature set at (C) a minimum temperature of [e.g. 6-8 ° C.] was selected to T _cc, also proportional band of the hot water outlet temperature [for example 50-60 ° C.] Is selected as Thc.

In addition, the openings of the control valves (V _R ), (V _H ), and (V _A ) are determined by the signals of the cold water outlet temperature sensor (Stc), the hot water outlet temperature sensor (Sth), and the controller (C), respectively. It is supposed to be adjusted. The control valve (V _A ) for the absorbing liquid may be controlled by the signal from the cold water outlet temperature sensor (Stc).

Next, an example of the operation of the control device having the above-described configuration, which is provided in this machine, will be described together with the operation of the dual-effect absorption chiller-heater (hereinafter referred to as "this machine") To do.

Now, when the machine is operated, for example, in the summer, the cooling load is usually large and the heating load is small in the summer, so that the chilled water output of the machine rarely becomes excessive with respect to the cooling load. Also, the hot water output is almost never insufficient for the heating load. The cold water outlet temperature of the machine is higher than the lower limit set value, and the hot water outlet temperature is lower than the upper limit set value. That is, Tcx> Tcc and Thx ≦ Thc. The signal switch (SC) is connected to the C side by the judgment signal of the temperature comparator (TC), which receives the signals from the hot and cold water outlet temperature sensors (Stc ₂ ) and (Sth ₂ ) and the signal from the temperature setting device (TSet). becomes, the fuel control valve (V _F) is the cold water outlet temperature sensor (St
The signal of c ₁ ) is proportionally controlled via the controller (C). That is, when the machine is operated in the summer, the amount of drive heat supplied to the machine is usually increased or decreased depending on the cooling load. In this case, the absorption liquid control valve (V _A ) is also proportionally controlled according to the cooling load, like the fuel control valve (V _F ). Further, the refrigerant control valve (V _R ) is proportionally controlled according to the cooling load by the signal from the cold water outlet temperature sensor (Stc). In addition, the refrigerant drain control valve (V _H ) in the water heater (8) is proportionally controlled according to the heating load by the signal from the hot water outlet temperature sensor (Sth). However, during summer operation, the heating load is zero or close to zero, so the refrigerant drain control valve (V _H ) is fully closed or an opening close to this.

In this way, in the summer, when the cooling load is large, the heating amount is automatically adjusted by the cooling water outlet temperature to obtain a chilled water output that almost matches the cooling load, and with the remaining power, it can be used for a small heating load. It is possible to take out the warm water output commensurate with it.

In addition, when the machine is operated in winter, the cooling load decreases while the heating load increases, contrary to summer, and the chilled water output of this machine tends to be excessive with respect to the cooling load, while the hot water output increases. On the other hand, the cold water outlet temperature is likely to drop and the hot water outlet temperature is unlikely to rise because the temperature tends to be insufficient. Then, in this case, the opening degree of the refrigerant control valve (V _R ) is decreased while the opening degree of the refrigerant drain control valve (V _H ) is increased, and, in addition, in the present machine, the high temperature generator (1) Since the resistance of the refrigerant flowing from the high temperature generator (1) to the water heater (8) is smaller than the resistance of the refrigerant flow to the condenser (3) via the heater (24) of the low temperature generator (2). In other words, the refrigerant circulation amount on the hot water output side, that is, on the hot water output side, is larger than that on the refrigeration cycle side, that is, on the cold water output side. Nevertheless, the rate of decrease of the cold water outlet temperature becomes faster than the rate of increase of the hot water outlet temperature. That is, the cold water outlet temperature reaches the lower limit value Tcc by the time the hot water outlet temperature reaches the upper limit value Thc. Under this temperature condition, that is, Tcx ≦ Tcc and Thx ≦ Thc, the connection of the signal switch (SC) is switched to the H side by the determination signal of the temperature comparator (TC), and the fuel control valve (V _F ) is a signal from the hot water outlet temperature sensor (Sth ₁ ) and is proportionally controlled via the controller (C).

In this way, in this machine, the heating amount is automatically adjusted by the hot water outlet temperature in the winter when the heating load is large, and a temperature output almost equal to the heating load is obtained. You can also take out the cold water output that matches. In addition, even when driving in the middle of spring or autumn,
The signal switch (SC) is connected to the H side under the temperature condition of Tcx ≦ Tcc and Thx ≦ Thc, such as when the number of cooling rooms sharply decreases while the number of heating rooms rapidly increases. When this temperature condition is reached, the coolant pump (P _R ) is stopped by the signal from the cold water outlet temperature sensor (Stc) to prevent freezing of the cold water, and the cold water (26) of the evaporator (4) is stopped. It is also possible to stop the spraying of the refrigerant liquid to the above).

Fig. 2 shows a concrete example of the control circuit of the signal switch (SC) of this machine. The hot and cold water outlet temperature sensors (Stc ₂ ), (St
h ₂ ), temperature setter (TSet) and temperature comparator (TC) functions such as cold water outlet temperature detection thermostat (TS ₁ ), hot water outlet temperature detection thermostat (TS ₂ ), relay connected to these It is included in a simple electric circuit. In this control circuit, the detected temperature of the cold water outlet temperature detection thermostat (TS ₁ ) is less than or equal to the lower limit value Tcc set for it, and the detected temperature of the hot water outlet temperature detection thermostat (TS ₂ ) is set for it When the value is Thc or less, the auxiliary relay (HR ₁ ) is de-energized while the auxiliary relay (HR ₂ ) is excited and the auxiliary relay contact (H
Both R ₁ ) and (HR ₂ ) are turned on, the relay (HR ₃ ) is excited and the switching contact (HR ₃ ) is connected to the H side. In addition, at other times, the switching contact piece (HR ₃ ) is connected to the C side. The switching of the control signal of such a fuel control valve by employing an inexpensive signal switching means constituted by a simple control circuit (V _F) can conveniently.

In addition, when both the heating and cooling loads are about the same in this machine, as described above, in this machine, the refrigerant vapor from the high temperature generator (1) first flows to the water heater (8) side rather than the refrigeration cycle side. Since a large amount of water flows, the opening of the refrigerant drain control valve (V _H ) is adjusted by the signal from the hot water outlet temperature sensor (Sth) so that it approaches the hot water output that is almost commensurate with the heating load, and the water heater (8 ) Is adjusted to the refrigerant circulation amount. Then, the refrigerant control valve (V _R ) is increased by the signal from the cold water outlet temperature sensor (Stc) so as to increase the flow rate of the refrigerant from the high temperature generator (1) to the refrigeration cycle side to compensate for the shortage of the cold water output with respect to the cooling load. The opening degree of is adjusted to be increased. Therefore, at this point, the normal cold water outlet temperature is higher than its lower limit set value Tcc, and the hot water outlet temperature is close to the desired temperature (for example, 55 ° C), in other words, lower than the upper limit set value Thc, and the signal switch (SC) connection is on the C side. The fuel control valve so that the cold water outlet temperature is at the desired temperature [for example 7 ° C.] (V _F) cold water outlet temperature sensor (St
It is adjusted via the controller (C) by the signal of c ₁ ) and adjusted to the heating amount which almost matches the heating and cooling load. in this way,
When both the heating and cooling loads are of the same size, the control unit controls the heating amount at the chilled water outlet temperature so that the input heat is first distributed so that the hot water output matches the heating load, and then the cooling The chilled water output is distributed to match the load, and as a result, capacity control is performed to match both loads.

Also, since the machine switches the connection of the signal switch (SC) while detecting both the hot and cold water outlet temperature,
Even when the heating load changes suddenly without changing the cooling load, or when the cooling load sharply decreases and the heating load increases rapidly, the conventional dual-effect absorption cooling temperature that switches the signal while detecting only the chilled water outlet temperature The followability and accuracy of the heating amount control are also improved compared to a water machine.

Of course, in this machine, not only the hot water of the water heater (8) can be supplied to the heating load, but also to the hot water supply load of the bath or the hot water pool.

(G) Effect of the Invention As described above, the present invention can easily select which of the hot and cold water outlet temperature sensors is used as the control signal for adjusting the heating amount with respect to the change in the load of the hot and cold water machine, and the heating amount. The effect of good control followability and the dual effect absorption chiller-heater with simultaneous supply of cold and hot water, and obtaining the hot and cold water output that almost matches the load regardless of the cold water load and hot water load. It has a high practical value as it is possible to supply cold and warm water at a stable temperature, such as the effect that it is possible to precisely control the amount of heat required.

[Brief description of drawings]

FIG. 1 is a schematic structural explanatory view showing an embodiment of a control device for a double-effect absorption chiller / heater simultaneously supplying cold / hot water according to the present invention,
FIG. 2 is a circuit diagram showing a specific example of the signal switching mechanism in the control device of the present invention. (1) …… High temperature generator, (2) …… Low temperature generator, (3)
… Condenser, (4) …… Evaporator, (5) …… Absorber,
(8) ... Water heater, (9), (10), (15), (20),
(21) …… pipe, (24) …… heater, (26) …… chiller,
(28) …… heat exchanger for hot water, (32), (34) …… tube,
(P _R ) …… Refrigerant liquid pump, (B) …… Burner, (St
c ₁ ), (Stc ₂ ), (Stc) ... Cold water outlet temperature sensor,
(Sth ₁ ), (Sth ₂ ), (Sth) …… Hot water outlet temperature sensor, (C) …… Controller, (SC) …… Signal switch, (TSe)
t) ... Temperature setter, (TC) ... Temperature comparator, (V _F ) ...
… Fuel control valve, (V _R )… Refrigerant control valve, (V _H )… Refrigerant drain control valve, (V _A )… Absorbing liquid control valve.

Claims (1)

[Claims] Claim: What is claimed is: 1. A cold water outlet temperature sensor and a hot water outlet temperature sensor of a double-effect absorption cold / hot water machine of simultaneous cold / hot water supply type, and control for adjusting a heating amount of the absorption cold / hot water machine by receiving signals from these temperature sensors. And a temperature setting device for setting the lower limit value of the cold water outlet temperature and the upper limit value of the hot water outlet temperature,
The temperature comparator compares the high and low of the temperature detected by the cold water outlet temperature sensor with respect to the lower limit value of the cold water outlet temperature of this temperature setting device and the high and low of the sensed temperature of the hot water outlet temperature sensor with respect to the upper limit value of the hot water outlet temperature, and the cold water outlet temperature In the case of a temperature condition where the temperature is below the lower limit value and the hot water outlet temperature is below the upper limit value, the signal from the hot water outlet temperature sensor is transmitted to the controller by the discrimination signal of the temperature comparator, while the temperature comparison is performed under the conditions other than the above temperature conditions. A control device for a double-effect absorption chiller-heater characterized by comprising a signal switcher for transmitting a signal from a chilled water outlet temperature sensor to a controller according to a discrimination signal of the container.