JPS60200062A - Controller for absopption heat pump - 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 (a) Industrial Application Field The present invention operates by keeping the pressure and temperature in the generator and condenser lower than the pressure and temperature in the evaporator and absorber. The present invention relates to a control device for an absorption heat pump (hereinafter referred to as this type of absorption heat pump) that takes out a heated fluid having a higher temperature than a heat source fluid supplied to an evaporator from an absorber.

(b) Prior art This type of absorption heat pump operates by keeping the pressure in the generator and condenser lower than the pressure in the evaporator and absorber, as described in, for example, Japanese Patent Laid-Open No. 58-69372. The generator and condenser are usually located below the evaporator and absorber, as shown in the figure. Then, when the operation is stopped, the dilute absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber is made to flow down into the concentrated absorption liquid in the generator to dilute the concentrated absorption liquid. Also, the example is JP-A No. 5
As explained in Japanese Patent No. 8-31262, when the operation is stopped, the refrigerant liquid in the evaporator or condenser is blown into the concentrated absorption liquid in the generator to dilute the concentrated absorption liquid. By diluting the absorption liquid in this way, it is possible to prevent the absorption liquid (lithium bromide aqueous solution) from crystallizing after the operation is stopped.

When restarting operation, first operate the pump (hereinafter referred to as absorption liquid pump) that sends diluted absorption liquid (hereinafter referred to as diluted liquid) to send diluted liquid from the generator to the absorber, and absorb this diluted liquid. The refrigerant vapor is separated by flowing down from the container to the generator via a solution heat exchanger and sprayed onto a heater built into the generator, and the separated refrigerant vapor is liquefied in a condenser. Next, when the amount of refrigerant in the refrigerant reservoir of the condenser exceeds a predetermined value, a pump (hereinafter referred to as the second refrigerant pump) sends the refrigerant to the refrigerant reservoir of the evaporator. When the amount of refrigerant liquid exceeds a predetermined value, the refrigerant liquid is returned to the evaporator from pump (hereinafter referred to as the first refrigerant pump) K, and is sprayed to the heat supply device built into the evaporator for evaporation, and the operation shifts to steady operation. That's what I do.

In the case of this method of starting operation, immediately after restarting operation, the refrigerant does not evaporate in the evaporator, and the temperature of the heated fluid flowing into the absorber is low, so the evaporator and absorber The pressure inside the vessel hardly increases.

Therefore, the pressure difference between the absorber and generator remains small,
The amount of dilute liquid flowing from the absorber to the generator via the solution heat exchanger and sprayed to the heater is small, and the refrigerant is separated in the generator in a small amount. If the amount exceeds a predetermined value, it will take a long time to sag. Furthermore, the refrigerant liquid is sent from the condenser to the evaporator, and the amount of refrigerant liquid in the refrigerant liquid reservoir of the evaporator reaches a predetermined value or more, and evaporation of the refrigerant in the evaporator starts, and the pressure in the evaporator and absorber increases. It took a long time to start rising.

As described above, conventional absorption heat pumps of this type have the disadvantage that it takes a long time to transition from restarting operation to steady operation, and that the start-up of operation is slow.

(c) Purpose of the Invention The purpose of the present invention is to provide an absorption heat pump of this type that can quickly start up operation.

B) Structure of the Invention The present invention provides an absorption heat pump of the type described above, in which a binox pipe for refluxing concentrated liquid to a generator or a binox pipe for dilute liquid to bypass a solution heat exchanger is provided. Then, by controlling the opening and closing of the control valve provided in the bypass pipe using the signal from the detector that detects the pressure inside the evaporator or the temperature of the refrigerant inside the evaporator, the amount of absorption liquid sprayed to the heater built into the generator is controlled. The configuration is such that the adjustment is possible.

According to the invention, the pressure difference between the absorber and the generator is small, and the operation is restarted with a small amount of absorption liquid flowing from the absorber to the generator via the solution heat exchanger and being sprayed to the heater of the generator. Even immediately after a conventional absorption heat pump of this type, a larger amount of absorption liquid can be distributed to the heater via the binox pipe, increasing the amount of refrigerant vapor generated in the generator. I can do it.

Therefore, in this kind of absorption heat pump equipped with the control device of the present invention, it does not take as much time as in the conventional absorption heat pump for the refrigerant liquid amount in the refrigerant liquid reservoir to reach a predetermined value or more. The time from the restart of operation until the refrigerant evaporates in the evaporator and the pressure in the evaporator and absorber rises can be shortened, allowing for faster start-up of operation compared to conventional absorption heat pumps of this type.

(E) Embodiment The drawing is a schematic structural explanatory diagram showing an embodiment of the control device for this type of absorption heat pump according to the present invention, and (1) is a lower stage consisting of a generator (2) and a condenser (3). The side generation condensation stage (4) is the upper evaporation absorption stage consisting of the evaporator (5) and the absorber (6), (7) is the solution heat exchanger, (8)
) and (9) are the first and second refrigerant pumps, respectively, and 00) is the absorption liquid pump. The reflux tube α ae, the tube to which the concentrated liquid is sent (17)
, (1 飄 (1! J, pipe in which diluted liquid flows down (2 (1), (
21) to form a circulation path for refrigerant (water) and absorption liquid (lithium bromide aqueous solution) similar to that of conventional absorption heat pumps of this type. Note that (22 is a heat exchange coil built into the solution heat exchanger (7)).

(2 East is the heater built in the generator (2), 04) is the cooler built in the condenser (3), (c) is the heat supply built in the evaporator (5), (26) is the absorption It is a heated device built into the heater (6).
, 301 is the cooler CI! C32+ is a pipe connected to the heat supply device (25) for flowing a heat source fluid such as waste hot water or waste steam, (01) is a pipe connected to the heat supply device (25), and is connected to 04) is a pipe connected to the heated device (a) through which heated fluid such as hot water or steam flows.

C35), (support)) are generator (2) and absorber (
6) Absorbent sprayer provided inside, 6'? ) is the evaporator (5
09 is the solution reservoir of the generator (2) and absorber (6), respectively (40, (4υ
are the refrigerant reservoirs of the condenser (3) and evaporator (5), respectively.
(421, (43 is an eliminator.

(SW,) is the liquid level switch installed in the solution reservoir (to), (
0 is the refrigerant liquid reservoir (liquid level controller provided in 401, (SW2
) is the refrigerant liquid reservoir (4υ liquid level switch, < Vo
) is a refrigerant liquid flow control valve provided in the pipe α4), and the absorption liquid pump (101) and the first refrigerant pump (8) are controlled by the liquid level switches (SW, ), (SW2), and liquid level controller (C), respectively.
), the second refrigerant pump (9) is controlled to start and stop to maintain the liquid level between the upper and lower limit set levels, and the liquid level controller (O controls the opening of the flow rate control valve (Vo)). The flow rate of the refrigerant liquid sent from the condenser (3) to the evaporator (5) is adjusted by controlling the temperature.

In the absorption heat pump (hereinafter referred to as this machine) with such a busy configuration, during steady operation, the generation condensation stage (11 side operates at a lower pressure than the evaporation absorption stage (4) side, and the absorber (6)
The heat generated when the concentrated liquid sprayed in the heated device (261) absorbs the refrigerant raises the temperature of the heated fluid in the heated device c!e, and the heat source fluid (e.g. waste steam) is ) The heated fluid (for example, hot water) is taken out at a higher temperature (for example, 116 degrees Celsius) than the temperature (for example, 80 degrees Celsius).

(This is a pipe for blowing refrigerant liquid that has a four-way on-off valve (V,). Before stopping the operation of this machine, open the on-off valve (■,) and use the conventional absorption heat pump of this type (hereinafter referred to as Similar to the conventional machine), the refrigerant liquid in the refrigerant reservoir (40, (41) is blown to the lower limit setting level of the liquid level by the second and first refrigerant pumps (9), (8), ) is diluted to perform dilution operation of the absorption liquid.

(The phrase refers to the absorption liquid pump (1 (l discharge side pipe side and sprayer 00
This is an absorption liquid bypass pipe connected to the lltl pipe (211), and this bypass pipe is equipped with a control valve (■). (Sl) (S2) are the refrigerant reservoir (41) and the pipe ( [6) A detector for detecting the temperature of the refrigerant liquid in (S,)
, (S4) are detectors that detect the pressure in the evaporator (5) and absorber (6), respectively, and the control valve (G) is controlled to open and close by a signal from either of these detectors. There is.

Next, we will explain an example of the operation of this machine at the start of operation, comparing it with the operation of a conventional machine that does not have a bypass pipe (451).

In this machine, immediately after the start of operation, the evaporative absorption stage (4)
The pressure on the side is, for example, about 60 +++ mHg, which is low (and the temperature of the refrigerant liquid in the tube (16) and the refrigerant reservoir (4υ) is, for example, about 42°C, and the value is low, so the detector The control valve (V) is fully opened by the signal of (S, ), (S2), (S3) or (S4), and the absorption liquid discharged by the absorption liquid pump (10) is transferred to the absorber (6) side and the generator. (2) side. Then, the absorption liquid that has been divided to the generator (2) side and the absorption liquid that flows down from the absorber (6) due to the head difference are transferred to the heater (c) by the sprinkler 05. The refrigerant vapor is liquefied in the condenser (3) and the liquid level in the refrigerant reservoir (40) rises, and when the liquid level exceeds a predetermined level, the liquid level controller ( The second refrigerant pump (9) is activated by the signal C), and the refrigerant liquid is sent to the evaporator (5) side.

On the other hand, in the conventional machine, the entire amount of the absorption liquid discharged by the absorption liquid pump uO) is sent to the absorber (6). Then, the absorption liquid that has flowed into the absorber (6) flows down again toward the generator (2) due to the head difference and is dispersed to the heater (23). However, at the beginning of operation, the pressure difference between the absorber (6) and the generator (2) is small and the amount of absorption liquid flowing down to the generator +21 side is small. The amount of refrigerant vapor generated in the generator (2) is small.

Therefore, in this machine, the refrigerant liquid reservoir (
4 [J] It does not take as long as the conventional machine for the liquid level to reach a predetermined level or higher, and the refrigerant liquid reaches the evaporator (5) more than the conventional machine.
Sent quickly to the side.

In this machine, the refrigerant liquid is sent to the evaporator (5) side and the liquid level in the refrigerant liquid reservoir (4υ) rises, and when this liquid level exceeds a predetermined level, the liquid level switch (SW2) is activated. The first refrigerant pump (8) operates according to the signal, and the heat supply device (25
), and evaporation of the refrigerant in the evaporator (5) is started. When the refrigerant starts to evaporate, the pressure on the evaporation and absorption stage (4) side gradually increases, and the unevaporated refrigerant in the evaporator (5) is also repeatedly heated by the heat supply device (25), so that the pipe (I6) , the temperature of the refrigerant liquid in the refrigerant liquid reservoir (41) also gradually rises. Then, the pressure difference between the absorber (6) and the generator (2) becomes too large, so that the flow rate of the absorption liquid flowing from the absorber (6) to the generator (2) via the solution heat exchanger (7) increases. gradually increases.The pressure on the evaporative absorption stage (4) side and the pipe α6),
As the temperature of the refrigerant liquid in the refrigerant reservoir (4]) increases, the detectors (81), (S2), (S3) or (
The control valve (G) is throttled in the closing direction by the signal S4), and when a predetermined value (for example, a pressure of 234 mmHg and a refrigerant liquid temperature of 70° C.) is reached, the control valve (3) is fully closed. Then, the machine shifts to steady operation.

In addition, the control valve (vK is 0N-instead of the valve that controls the opening degree)
It is also possible to use an OFF valve. Also,
Bypass pipe (four are connected to pipe (181) instead of connecting pipe (181)
9) may be connected.

Furthermore, in place of the bypass pipe (45), a control valve (bypass pipe (45) with This is connected to the pipe (2I) on the artificial side of vessel 09, so that the absorbing liquid can bypass the heat exchange coil, which has a large flow resistance, and flow down to the artificial generator (2) side.

In this machine, the temperature of the heat source fluid and the cooling fluid fluctuates, and the pressure difference between the evaporation absorption stage (4) and the generation condensation stage (11) fluctuates, and the temperature changes from the absorber (6) to the solution heat exchanger (11). 7) Even when the flow rate of the absorption liquid flowing down to the generator (2) via the generator (2) changes, the opening degree of the control valve (■) is controlled to
It is possible to reduce fluctuations in the amount of absorption liquid sprayed to the generator (2) and the absorber (6), and to prevent uneven distribution of absorption liquid between the generator (2) and the absorber (6).
It also has the advantage of being able to continue stable operation.

(f) Effects of the Invention As described above, the present invention provides an absorption heat pump of this kind that, at the start of operation when the flow rate of the absorption liquid flowing down from the absorber to the generator via the solution heat exchanger is small, If a large amount of absorption liquid is sprayed into the heater of the generator through the evaporator, the amount of refrigerant vapor generated in the evaporator at the start of operation can be increased. Therefore, according to the invention:
It does not take as much time as with conventional absorption heat pumps for the amount of refrigerant in the refrigerant reservoir to exceed a predetermined value, and f! ,
I = 17, 3 - O 5.11 - 3

[Brief explanation of the drawing]

The drawing is a schematic structural explanatory diagram showing one embodiment of a control device for an absorption heat pump of this type according to the present invention. (1)...Generation and condensation stage, (2)...Generator, (
3)... Condenser, (4)... Evaporative absorption stage, (5)
... Evaporator, (6) ... Absorber, (7) ... Solution heat exchanger, (8), (9) ... First. Second refrigerant pump, (101... absorption liquid pump, (16), f
lgl, (IL(2o+, (21)...tube, (22
...Heat exchange coil, (231... Heater, C4
)... Cooler, (251... Heater, C26)
... Heated device, C351 ... Spreader, (c), C
31...Solution reservoir, (4o), (4υ...Refrigerant reservoir, (4th limit...Bypass pipe, (C1...
Controller, (SWI), (SW,)...Liquid level switch,
(S,), (S, > (S3), (S4)...detector,
M...Control valve. Applicant Sanyo Electric Co., Ltd. and one other agent Patent attorney Shizuo Sano

Claims (1)

[Claims] (1) Heat source fluid is supplied to the generator and evaporator while cooling fluid is flowing to the condenser, and the heated fluid at a temperature higher than the temperature of the heat source fluid is taken out from the absorber. In an absorption heat pump consisting of a pipe-connected solution heat exchanger and a solution heat exchanger, there is an absorption heat pump that connects the discharge side of the pump that sends the absorption liquid from the generator to the absorber and the inlet side of the absorption liquid dispersion provided in the generator. A bypass pipe or a bypass pipe for the absorption liquid connecting the absorption liquid absorber outlet side and the distribution dense inlet side is arranged so that the absorption liquid bypasses the solution heat exchanger and flows down from the absorber to the dispersion device. An absorption heat pump characterized in that the bypass pipe is provided with a control valve, and the opening and closing of the control valve is controlled by a signal from a detector that detects the pressure in the evaporator or the temperature of the refrigerant in the evaporator. control device.