JPH05223391A - Absorption cold/warm water device - Google Patents

Abstract

PURPOSE:To obtain an absorption cold/warm water device in which an operation can be performance in a high efficiency without decreasing a COP, a load can be controlled with a relatively simple structure and a facility cost is low in the device of the structure having a solution return passage. CONSTITUTION:An absorption cold/warm water device has a high temperature regenerator 2, a low temperature regenerator 3, a condenser 4 and a solution pump 8. The regenerator 2 has a gas/liquid separator 12. The oven also has a solution return passage 13 for returning solution from the separator 12 to the high temperature regenerator. The device comprises first control means 15 for so controlling an operation of the pump 8 that a level position of the solution is held constant in the separator 12. The oven also comprises first valve means 17 for switching the passage in an intermediate concentration solution passage 16 in which solution flows from the separator 12, and second control means 21 for controlling the means 17 to an open side when a solution temperature in the separator 12 becomes a predetermined value or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller-heater equipped with a gas-liquid separator in a regenerator and provided with a solution return path for returning a solution from the gas-liquid separator to the regenerator.

[0002]

2. Description of the Related Art An absorption chiller-heater equipped with such a solution return path will be explained by taking, for example, a double-effect absorption chiller-heater as a high-temperature regenerator.
It has been recently proposed to prevent the occurrence of empty cooking in a high temperature regenerator in response to the technical demand for downsizing the absorption chiller / heater. If this solution return path is provided, when the solution path after the high temperature solution heat exchanger (gas-liquid separator) is closed, one closed solution circuit across the high temperature regenerator, the gas-liquid separator and the solution return path will be created. Once formed, the solution will circulate within this closed circuit.

Conventionally, load control in an absorption chiller-heater has been performed by using combustion side control and solution circulation side control in combination, and these controls are performed such as start-up and steady operation of the absorption chiller-heater. It was used in an appropriate combination depending on the situation. As an example of the combustion side control, there is a method of proportionally controlling the gas valve and the air valve of the combustion section by a control motor, or the gas flow rate adjusting valve by proportional control, and combining and controlling the combustion fan by an inverter. As the solution circulation side (quantity) control, there is a method such as proportional control of a solution pump by an inverter.

[0004]

However, in such load control, for example, the return cold water temperature is detected and the combustion gas flow rate, the combustion air flow rate, the solution circulation flow rate, etc. are simultaneously determined according to the load / start / stop situation. Since it needs to be controlled, there are the following problems. 1. The control system is complicated. 2. Since it is necessary to incorporate a device such as an inverter, the cost becomes high. 3. In order to maintain a constant solution concentration difference (concentration difference between concentrated solution and diluted solution) in the cycle (which causes COP drop when the concentration range becomes unstable), it is necessary to strictly control the solution circulation amount according to the combustion amount. Is. Therefore, it is an object of the present invention to enable highly efficient operation of an absorption chiller-heater configured to have a solution return path without lowering COP and to perform load control with a relatively simple configuration. It is possible to obtain an absorption chiller-heater with low equipment cost.

[0005]

In order to achieve this object, the feature of the absorption chiller-heater according to the present invention is that the solution pump is operated so that the solution surface position in the gas-liquid separator is kept constant. In addition to providing the first control means for controlling, in the medium-concentration solution passage through which the solution flows from the gas-liquid separator, the first valve means for opening and closing the flow path is provided, and the first valve means is the solution in the gas-liquid separator. There is a second control means for controlling the open side when the temperature is above a certain value and the closed side when the temperature is below a certain value.
The effects are as follows.

[0006]

That is, in this absorption chiller-heater, the liquid level in the gas-liquid separator is kept constant by the solution pump control by the first control means, and the first valve means is provided in the medium-concentration solution passage. The second valve means controls the first valve means to open when the solution temperature in the gas-liquid separator reaches a constant value.

The steady operation state and the rising state will be separately described below. (1) Steady operating state In this state, for example, when the solution temperature in the gas-liquid separator rises to a constant temperature, the first valve means is operated to the open side,
Medium liquid flows out. When the middle liquid flows out, the liquid level of the gas-liquid separator lowers, the first control means operates, and the dilute solution is supplied to the regenerator. When this supply is performed, the temperature of the solution in the gas-liquid separator decreases, the flow rate of the medium solution decreases, and the flow rate of the dilute solution also decreases due to the function of the second control means, so that the solution temperature in the gas-liquid separator decreases. It is kept almost constant and stable operation is possible (at this time, the concentration of the solution is also kept almost constant). Therefore,
In this configuration, when the heat input of the regenerator is large, the solution temperature in the gas-liquid separator easily rises, so the flow rate of the middle liquid increases overall, but the temperature and pressure on the refrigeration cycle are kept almost constant. As a result, the refrigerating capacity is maintained in a good state. On the other hand, when the heat input to the regenerator is small, the opposite occurs and the refrigerating capacity decreases while the temperature and pressure of the refrigeration cycle remain constant (while the concentration difference is maintained). In such a situation, the coefficient of performance does not change much in any case because the temperature and pressure of the refrigeration cycle are almost constant. Therefore, by proportionally controlling only the heat input amount (combustion amount) of the regenerator by the load, it is possible to perform accurate proportional control of the refrigerating capacity without lowering the efficiency.

(2) Behavior at start-up When the temperature of the solution is low as when the absorption chiller-heater starts up, the medium-concentration solution in the medium-concentration solution passage is separated into gas and liquid by the action of the second control means. It does not flow unless the temperature of the solution in the vessel reaches a constant temperature. Therefore, the solution will repeat the solution circulation between the regenerator and the gas-liquid separator, and since the dilute solution will not be supplied, the liquid temperature in the gas-liquid separator will rise quickly and the frozen The cycle starts faster. Here, in the configuration of the present application, the combustion control is performed as usual. However, the control on the solution circulation side will be performed as described above. Therefore, when this control configuration is adopted, the solution circulation side is automatically adjusted and operated by the control according to the load on the combustion side.

[0009]

Therefore, the following advantages can be obtained by adopting the configuration of the present application. 1. The load can be controlled with a very simple control system, and there are few failures and reliability is improved. 2. The combustion amount control and the solution flow rate control are independent, and since the solution flow rate is automatically determined according to the combustion amount, it is less likely to be affected by disturbance. 3.2. In connection with the above, the concentration range of the concentrated-dilute solution is always constant and the COP does not decrease. 4. Can be configured as a simple and inexpensive system. 5. Starts up quickly. 6. Since the liquid level in the gas-liquid separator is controlled to be constant, the gas-liquid separation can be reliably performed.

[0010]

1 is a system diagram of an absorption chiller-heater 1. First, the system configuration of the absorption chiller-heater 1 will be described with reference to FIG. This absorption chiller-heater 1 is a so-called double-effect absorption chiller-heater, and has a high-temperature regenerator 2
Also, the low temperature regenerator 3, the condenser 4 provided on the downstream side of the vapor path of the low temperature regenerator 3, the evaporator 6 that performs heat exchange with the cooling system of the indoor unit 5, and the absorption liquid absorbs water vapor from the evaporator 6. An absorber 7, a solution pump 8, a low temperature solution heat exchanger 9, a high temperature solution heat exchanger 10 and the like are provided.

Next, the structure around the high temperature regenerator 2 will be described in more detail. The high temperature regenerator 2 is supplied with the dilute solution from the dilute solution introduction path 11 and is regenerated in the regenerator 2 to be disposed at a higher position than the high temperature regenerator 2. To the concentrated solution and steam. The gas-liquid separator 12 is configured to include an inflow check valve in the liquid inflow portion 12a and a level switch 12b inside, and the vapor side is connected to the vapor path of the low temperature regenerator 3 and the solution side is high temperature solution heat. It is connected to the solution section of the low temperature regenerator 3 via the exchanger 10. Now, between the gas-liquid separator 12 and the dilute solution introduction path 11 described above, a solution return path 13 for introducing the solution separated by the gas-liquid separator 12 to the dilute solution introduction path 11 is provided, and Further, the solution is transferred from the dilute solution introduction path 11 to the gas-liquid separator 1 via the solution return path 13 described above.
A check valve 14 is provided to prevent flow to 2.
By adopting such a configuration, the following operating conditions are created. That is, in the regenerator 2, the dilute solution undergoes a regenerating operation to become vapor and boiling liquid, and these vapor and boiling liquid are admixed to the gas-liquid separator 12 in a mixed state. Here, in a normal operating state in which the dilute solution is sequentially supplied to the high temperature regenerator 2 by the solution pump 8, the check valve 1
4 is kept closed and the vapor and concentrated solution are respectively admitted to the designated equipment. On the other hand, if the supply of the dilute solution to the high temperature regenerator 2 is interrupted for some reason, the check valve 14 provided in the dilute solution introduction path 11 is opened, and the gas-liquid separator 12 is passed through the solution return path 13. Through the dilute solution introduction path 11
The solution is supplied to the high temperature regenerator 2 to avoid the problem of empty cooking.

The characteristic components of the absorption chiller-heater 1 of the present invention will be described below. First, the solution pump 8 is provided with a first control device 15 as first control means for controlling the operation / stop of the solution pump 8 so as to keep the solution surface position in the gas-liquid separator 12 constant. There is. Further, as shown in FIG. 1, the medium concentration solution path 16 from the high temperature solution heat exchanger 10 to the low temperature regenerator 3 is provided with a first electromagnetic opening / closing valve 17 as a first valve means, and the low temperature regenerator 3 is provided. A second electromagnetic opening / closing valve 20 as a second valve means is provided in the vapor path 19 extending from the flash chamber 18 to the flash chamber 18. The first electromagnetic on-off valve 17, the second control means for controlling the opening and closing of the second electromagnetic on-off valve 20, the second control device 21 and the third control device 22 as the third control means are respectively provided. Here, the control by the second control device 21 controls the first electromagnetic on-off valve 17 to the open side when the temperature of the solution in the gas-liquid separator 12 becomes a certain value or more, and to the closed side when the solution temperature becomes less than the certain value. The third control device 22 controls the second electromagnetic on-off valve 20 to the open side when the vapor temperature at the outlet of the gas-liquid separator 12 becomes a certain value or more and to the closed side when the vapor temperature becomes less than the certain value. Is.

More specifically, the gas-liquid separator 1
The level switch 12b in 2 is provided to start and stop the solution pump 8, and the first electromagnetic on-off valve 17 is opened and closed by the liquid temperature in the gas-liquid separator 12 (for example, set temperature 167 ° C.). It becomes (open on the high temperature side). Here, the combustion control in the high temperature regenerator is performed as usual.
That is, for example, by detecting the return cold water temperature, the combustion gas flow rate,
The flow rate of combustion air is controlled. Furthermore, high temperature regenerator 2
In order to suppress the internal pressure fluctuation as much as possible, the second electromagnetic opening / closing valve 20 is opened / closed (opened on the high temperature side) by the saturated steam temperature of the steam temperature at the outlet of the gas-liquid separator 12 (for example, the set value 115 ° C.).

With this structure, when the first or second solenoid valves 17 and 20 are maintained in the closed state, the inside of the solution circulation path through the high temperature regenerator 2, the gas-liquid separator 12 and the solution return path 13 The solution circulates through the regenerator 2
The concentration of the dilute solution can be increased with high efficiency by heating with the combustion device provided in the. Further, in the steady operation state, the concentration of the solution flowing out from the gas-liquid separator 12 is increased by the first and second control devices 15 and 21 or the first to third control devices 15, 21 and 22 working together. ,
It is efficiently maintained at a predetermined concentration, and as a result, high-performance operation while maintaining a high COP is possible.

[Other Embodiments] In the above embodiments, an example of a double-effect absorption chiller-heater was shown, but this structure can also be adopted in a single-effect absorption chiller-heater. is there. Furthermore, it is not necessary to use a solenoid valve,
This may be any structure that can open and close the flow path. Therefore, these valves are simply referred to as valve means, and the control device can be arbitrarily configured.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a diagram showing a system configuration of an absorption chiller-heater.

[Explanation of symbols]

 2 high temperature regenerator 3 low temperature regenerator 4 condenser 8 solution pump 12 gas-liquid separator 13 solution return path 15 first control means 16 medium concentration solution path 17 first valve means 20 second valve means 21 second control means 22 second Three control means

Claims (3)

[Claims] 1. A high temperature regenerator (2), a low temperature regenerator (3),
With a condenser (4) and a solution pump (8),
In an absorption chiller-heater provided with a gas-liquid separator (12) in the high temperature regenerator (2) and provided with a solution return path (13) for returning a solution from the gas-liquid separator (12) to the high temperature regenerator, The gas-liquid separator (12) is provided with first control means (15) for controlling the operation of the solution pump (8) so that the solution surface position in the gas-liquid separator (12) is kept constant. ) To the medium-concentration solution passage (16) through which the solution flows, the first valve means (1) for opening and closing the passage.
7) is provided, and the second control means (21) for controlling the first valve means (17) to the open side when the solution temperature in the gas-liquid separator (12) is a certain value or more and to the closed side when the solution temperature is less than the certain value. ) Provided absorption cold water heater. 2. A second valve means (20) for opening and closing a flow path is provided in a vapor path from the gas-liquid separator (12) to the condenser (4), and the second valve means (20). ) To the open side when the vapor temperature at the outlet of the gas-liquid separator (12) is a certain value or higher,
The absorption chiller-heater according to claim 1, further comprising third control means (22) for controlling to a closed side when the value is less than a certain value. 3. Absorption cold / hot water provided with a regenerator, a condenser, and a solution pump, the regenerator having a gas-liquid separator, and a solution return path for returning a solution from the gas-liquid separator to the regenerator. In the machine, with the first control means for controlling the operation of the solution pump so as to keep the solution surface position in the gas-liquid separator constant, a medium-concentration solution in which the solution flows out of the gas-liquid separator The passage is provided with a first valve means for opening and closing the flow passage, and the first valve means is opened to the open side when the solution temperature in the gas-liquid separator is a certain value or more.
An absorption chiller-heater equipped with a second control means for controlling to a closed side when the value is less than a certain value.