JPS598743B2 - Nijiyūkōyoukiyūsyureitosouchi - Google Patents

Description

Detailed Description of the Invention The present invention provides an absorption refrigeration system in which two generators, a low-temperature generator and a high-temperature generator, are provided for the purpose of heat recovery to perform a dual-effect absorption refrigeration cycle. It is related to.

In conventional dual-effect absorption refrigerators, the absorption solution from the absorber is sent to a high-temperature generator via a low-temperature heat exchanger and a high-temperature heat exchanger using a solution pump, and then to a low-temperature generator after passing through a high-temperature heat exchanger. The circulation cycle is repeated through which the solution is returned to the absorber via a low-temperature heat exchanger.In the case of this dual-effect refrigeration cycle, the pressure inside the high-temperature generator is increased and the pressure difference is used to send the solution to the low-temperature generator. The solution in the low temperature generator is heated with steam (within about 100°C) generated from the high temperature generator.

Therefore, the concentration of the concentrated solution is the concentration at the outlet of the low-temperature generator, and since the low-temperature generator is normally heated with steam at a temperature of less than 100°C, it cannot be concentrated very much, and there is a limit to the increase in refrigeration efficiency. In order to increase the concentration, it is necessary to increase the pressure of the refrigerant vapor generated in the high-temperature generator, which exceeds atmospheric pressure and is subject to legal restrictions as a pressure vessel (class 1 pressure vessel), making the structure expensive. Therefore, maintenance and safety became troublesome, and there were many problems in handling.

The present invention effectively improves many of these problems, lowers the pressure in the high temperature generator section of a dual-effect absorption refrigeration cycle, and
Another object of the present invention is to provide a dual-effect absorption refrigeration system that increases the cycle concentration range and is extremely efficient.

Another object of the present invention is to provide a type of dual-effect absorption refrigeration system that is capable of suppressing the pressure in the high-temperature generator section below atmospheric pressure, is easy to manufacture, and is inexpensive. Our goal is to provide the following.

Furthermore, in the present invention, prevention of overconcentration in the high temperature generation part,
One of the objectives is to provide a device that can accurately prevent cavitation in the solution pump used, ensure safe and stable refrigeration operation, and be extremely easy to handle.

The present invention comprises an absorber, a high temperature generator, a low temperature generator, a condenser,
In a dual-effect absorption refrigeration system equipped with an evaporator, a high-temperature common liquid heat exchanger, a low-temperature solution heat exchanger, a solution pump, a refrigerant pump, and a solution path and a refrigerant path that connect these devices, the solution in the absorber is A part of the heated and concentrated solution is guided by the solution pump to the low temperature generator via the low temperature solution heat exchanger, and a part of the heated and concentrated solution is guided to the high temperature generator via the high temperature solution heat exchanger. The solution is guided to the low-temperature solution heat exchanger via a return passage through a high-temperature solution heat exchanger, and the remainder of the solution heated and concentrated by the low-temperature generator is guided to the return passage or the low-temperature solution heat exchanger. The present invention, which is a dual-effect absorption refrigeration system, will be described with reference to the drawings.In the specific example shown in FIG. a low-temperature heat exchanger 3 as a container, a low-temperature generator 4, a high-temperature heat exchanger 5 as a high-temperature solution heat exchanger, a high-temperature generator 6,
The absorption solution circulation path leading to the high temperature heat exchanger 5, the low temperature heat exchanger 3, and the absorber 1, the absorber 1, the absorber solution pump 2, the low temperature heat exchanger 3, the low temperature generator 4, (some of which is evaporated) (to condenser 7), high temperature heat exchanger 5, high temperature generator 6, low temperature generator 4
, a condenser 7, an evaporator 8, and a refrigerant circuit leading to the absorber 1, so as to perform a double-effect absorption refrigeration cycle.

The low-temperature generator 4 and the high-temperature generator 6 are connected by a solution pipe 10, which is equipped with a solution pump 9 and serves as an intermediate solution passage passing through the high-temperature heat exchanger 5, and a refrigerant pipe 11, and the absorber 1 is an absorber solution pump 2 and a low temperature heat exchanger 3
The solution from the high temperature generator 6 is connected to the absorber 1 through a pipe 13 passing through the high temperature heat exchanger 5 and the low temperature heat exchanger 3, a return passage 14, and a pipe 15.
The liquid is then returned to and poured into an absorber tube 25 which serves as a cooling tube.

Instead of pouring into the absorber tube 25, it may be returned to the solution reservoir at the bottom of the absorber 1.

However, it is preferable to pour it into the absorber tube 25 in order to increase the heat recovery and absorption effect.

The solution heated and concentrated in the low temperature generator 4 is divided into two parts, a part of which is guided to the high temperature generator 6 via a high temperature heat exchanger 5 via a pipe 10 serving as an intermediate solution passage, and the remainder is led to a return passage 14. Alternatively, it is guided to the low temperature heat exchanger 3 without passing through the high temperature heat exchanger 5.

Thereby, generation of crystals in the low temperature heat exchanger 5 can be prevented.

In this case, the cycle becomes a temperature-concentration diagram as shown in FIG. 1A.

In order to divide the solution heated by the low temperature generator 4 into two,
In this embodiment, the overflow wall 37 provides an overflow liquid reservoir 4' as a part of the overflow.

The part of the solution that does not overflow is passed through the solution pipe 10 by the solution pump 9, passes through the high temperature heat exchanger 5, and reaches the high temperature generator 6.

The remaining overflow solution enters the overflow reservoir 4' and is led to the return passage 14 connecting the high temperature heat exchanger 5 and the low temperature heat exchanger 3 or to the low temperature heat exchanger 3 through the passage 33.

When a part of the overflow is provided, when the solution pump 9 is provided in the piping 10, a head of the solution is ensured, and this helps to prevent cavitation of the solution pump 9.

In the figure, 20 is a refrigerant pump, 21 is a refrigerant circulation path, 22 is a spray pipe, and 23 is a pipe that connects the condenser 7 and the evaporator 8.

24 is a low temperature generator tube, 26 is a high temperature generator tube, 27 is a condenser tube, 28 is an evaporator tube, 35
is provided as necessary with a control valve such as a float valve.

36 is a steam valve.

The solution pump 9 is connected to the low temperature heat exchanger outlet and the absorption side of the solution pump 9 by a bypass pipe 17 having a throttle mechanism 16 such as an orifice or a pressure reducing valve in the piping 12 as required.
A portion of the dilute solution can be added to the pump to supercool it and help prevent cavitation in the pump.

Alternatively, the solution pipe 10 may also be connected to a bypass pipe 19 having a throttle mechanism 18 such as an orifice or a pressure reducing valve to the high temperature heat exchanger 5.
, and connect it to the heating side of the high-temperature heat exchanger 5 so that a part of the solution enters the heating side of the high-temperature heat exchanger 5 to prevent crystallization of the high-temperature heat exchanger. It can also be useful.

In these cases, a structure may be adopted in which the flow of a portion of the bypassed solution is automatically interrupted in order to selectively flow through the flow, and these structures may be appropriately incorporated into each of the embodiments described later. You can also do it.

In the embodiment shown in FIG. 2, a tank 30 forming a flash chamber 29 is provided in the return passage 14 between the heating side of the high temperature heat exchanger 5 and the heating side of the low temperature heat exchanger 3 in the previous example. The gas phase portion of the tank 30 and the gas phase portion of the low temperature generator 4 are connected through a refrigerant vapor pipe 31.

The refrigerant vapor generated by the flashing of the solution in the tank 30 is sent to the low temperature generator 4 through a pipe 31 to increase the concentration range and help improve efficiency.A tube that adds heat to the flash tank 30 as needed 32 may also be provided.

For example, in order to further increase the concentration, the tube 32 that provides a heat exchange effect may be used as the exhaust gas source or as the tube 2 of the high temperature generator 6.
It is effective to connect it to 6 and apply heat to further increase the concentration range.

The cycle in this case is as shown in FIG. 2A.

Also, the solution in the overflow liquid reservoir 4' is transferred to the solution pipe 34.
It may also be guided to the flash chamber 29 by.

In FIG. 3, the tank 30 can be replaced by the overflow reservoir 4' of the low temperature generator 40, and the flash chamber 29 can also be used as the outlet of the low temperature generator.

FIG. 4 shows part of an alternative embodiment in which instead of using the solution pump 9 to direct the solution from the low temperature generator 4 to the high temperature generator 6, an ejector 9' is used, and the absorber solution pump 2 The diluted solution is applied to the ejection side using the discharge pressure of The low temperature generator 4 is connected to the high temperature generator 6 so that the solution can be pumped by suction.

In this case, the cycle becomes a temperature-concentration diagram as shown in FIG. 4A.

In this example, the bypass pipe bypassed from the solution pipe 12 is used as the ejection pipe 12', but it can also be constructed in a system with other dedicated pumps if necessary.

When the solution pump 9 is used, the temperature of the solution is high and the motor temperature rises, but this can be avoided by using the ejector 9', which improves the operational efficiency and safety of the absorption refrigeration cycle. This makes it possible to ensure integrity.

Further, the concentration of the solution entering the high temperature generator 6 can be lowered, and the range of concentrated concentration in the high temperature generator 6 can be increased.

Ejector 9' can also be used in place of solution pump 9 in other embodiments.

Since the above embodiment is configured and operates as described above, when the pressure of the high temperature generator is kept constant, the cycle concentration range can be widened, and the efficiency can be significantly improved.Moreover, the return from the low temperature heat exchanger Since the bath liquid concentration can be lower than that of conventional products, there is no need to increase the pressure of the refrigerant vapor generated in the high-temperature generator, and the pressure in the high-temperature generator can be kept below atmospheric pressure. As a simple high-temperature generator part that can be operated and avoids legal restrictions on equipment configuration, the entire equipment can be constructed at a low cost, and by ensuring high operating efficiency, the overall utilization efficiency is increased and the absorption chiller The operation of the absorption refrigeration system can be carried out extremely safely and economically, and the simplification of the auxiliary equipment of the absorption refrigeration system has the effect of simplifying operational maintenance and safety handling.

According to the present invention, it is possible to provide a dual-effect absorption refrigeration device that exhibits the following practical effects.

(1) Efficiency can be improved by reducing the amount of solution sent to the high temperature generator and widening the concentration range.

(2) The high temperature generator can be operated with its pressure kept below atmospheric pressure.

(3) Since the medium concentration solution from the low temperature generator is mixed into the high concentration solution from the outlet of the high temperature generator to lower the concentration, crystal formation can be prevented.

(4) Cavitation of the pump that sends the solution from the low-temperature generator to the high-temperature generator can be prevented.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention, and FIGS. 1 to 3 are flow diagrams, FIG. 4 is a partial flow diagram, and IA, 2A, and 4A.
The figures are temperature-concentration diagrams for the cycles of Figures 1 and 2.4, respectively. 1...Absorber, 2...Solution pump, 3
...Low temperature heat exchanger, 4...Low temperature generator, 4'...Single bar flow liquid reservoir, 5...
・High-temperature heat exchanger, 6... High-temperature generator, 7...
...Condenser, 8...Evaporator, 9...
Solution pump, 9'...Ejector, 10...
...Solution piping, 10'...Piping, 11...
...Refrigerant piping, 12...Solution piping, 12'.
...Ejection pipe, 13...Piping, 14...
... Return passage, 15 ... Piping, 16 ...
...Aperture mechanism, 17...Bypass pipe, 18...
... Orifice, 19 ... Bypass pipe, 2
0... Refrigerant pump, 21... Refrigerant circulation, 22... Spray pipe, 23... Piping, 24... Low temperature generator tube , 25...
...Absorber tube, 26...High temperature generator tube, 27...Condenser tube, 28...
...Evaporator tube, 29...Flash chamber,
30... Tank, 31... Refrigerant vapor piping, 32... Tube, 33... Passage, 34... Solution piping, 35. ... Control valve, 36 ... Steam valve, 37 ... Overflow wall.

Claims (1)

[Claims] 1. Absorber, high temperature generator, low temperature generator, condenser, evaporator, high temperature solution heat exchanger, low temperature solution heat exchanger, solution pump,
Regarding a dual-effect absorption refrigeration system equipped with a refrigerant pump, a solution path connecting these devices, and a refrigerant path, the solution in the absorber is guided by the solution pump to the low temperature generator via the low temperature solution heat exchanger, A portion of the heated and concentrated solution is guided to the high temperature generator via the high temperature solution heat exchanger, and the heated and concentrated solution is guided to the low temperature solution heat exchanger via the return passage through the high temperature solution heat exchanger, A dual-effect absorption refrigeration apparatus characterized in that the remainder of the solution heated and concentrated by the low temperature generator is guided to the return passage or the low temperature solution heat exchanger. 2 Absorber, high temperature generator, low temperature generator, condenser, evaporator, high temperature solution heat exchanger, low temperature solution heat exchanger, solution pump,
In a dual-effect absorption refrigeration system equipped with a refrigerant pump, a solution path connecting these devices, and a refrigerant path, an overflow portion is provided at the solution outlet of the low temperature generator, and the solution in the absorber is transferred to the solution pump. Guide the solution through the low temperature solution heat exchanger to the low temperature generator, guide the heated and concentrated solution to the overflow part, and guide the solution that does not overflow to the high temperature generator via the high temperature solution heat exchanger, The heated and concentrated solution is guided to the low temperature solution heat exchanger via the return passage through the high temperature solution heat exchanger, and the overflow solution is guided to the return passage or the low temperature solution heat exchanger. A dual-effect absorption refrigeration device featuring: 3 Absorber, high temperature generator, low temperature generator, condenser, evaporator, high temperature solution heat exchanger, low temperature solution heat exchanger - solution pump,
In a dual-effect absorption refrigeration system equipped with a refrigerant pump, a solution path connecting these devices, and a refrigerant path, an overflow portion is provided at the solution outlet of the low temperature generator, and the solution in the absorber is transferred to the solution pump. Guide the solution through the low temperature solution heat exchanger to the low temperature generator, guide the heated and concentrated solution to the overflow part, and guide the solution that does not overflow to the high temperature generator via the high temperature solution heat exchanger, The heated and concentrated solution is guided through the high temperature solution heat exchanger to the low temperature solution heat exchanger through a return passage, a flash chamber is provided in the return passage, and the gas phase portion of the flash chamber is connected to the gas phase of the low temperature generator. A dual-effect absorption refrigeration apparatus, characterized in that the overflow solution is communicated with the above-mentioned return passageway, the low-temperature solution heat exchanger, or the flash chamber. 4 Absorber, high temperature generator, low temperature generator, condenser, evaporator, high temperature solution heat exchanger, low temperature solution heat exchanger, solution pump,
In a dual-effect absorption refrigeration system equipped with a refrigerant pump, a solution path connecting these devices, and a refrigerant path, an overflow is provided at the solution outlet of the low temperature generator, and the solution in the absorber is pre-empted by the solution pump. d1 The heated and concentrated solution is introduced into the low temperature generator through the low temperature solution heat exchanger, and the heated and concentrated solution is poured into the overflow part, and the solution that does not overflow is passed through the high temperature solution heat exchanger through the intermediate solution path and into the high temperature solution. The heated and concentrated solution is guided through the high-temperature solution heat exchanger to the low-temperature solution heat exchanger via the return passage, and the overflow solution is guided to the return passage or the low-temperature solution heat exchanger. A dual-effect absorption refrigeration apparatus, characterized in that the intermediate solution passage is provided with an ejector driven by the discharge pressure of the solution pump, and the ejector transfers the solution in the intermediate solution passage. 5 Absorber, high temperature generator, low temperature generator, condenser, evaporator, high temperature solution heat exchanger, low temperature solution heat exchanger, solution pump,
In a dual-effect absorption refrigeration system equipped with a refrigerant pump, a solution path connecting these devices, and a refrigerant path, an overflow portion is provided at the solution outlet of the low temperature generator, and the solution in the absorber is transferred to the solution pump. The heated and concentrated solution is guided to the low temperature generator via the low temperature solution heat exchanger, and the heated and concentrated solution is guided to the overflow part, and the solution that does not overflow is passed through the high temperature solution heat exchanger through the intermediate solution passage to the high temperature generator. The heated and concentrated solution is introduced into the low temperature solution exchanger through the high temperature solution exchanger and into the low temperature solution exchanger via a return passage, a flash chamber is provided in the return passage, and the gas phase portion of the flash chamber is transferred to the low temperature solution exchanger. communicating with the gas phase part, and guiding the overflow solution to the return passage, the low temperature solution heat exchanger, or the flash chamber, and the intermediate solution passage having an ejector driven by the discharge pressure of the solution pump. A dual-effect absorption refrigeration apparatus characterized in that the ejector is used to transfer the solution in the intermediate solution passage.