JPS6014987B2 - Dual effect absorption heating and cooling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a dual-effect absorption refrigeration system that performs an absorption refrigeration cycle using cold soot liquid and an absorption solution. This relates to heating and cooling equipment.

In order to perform a heating cycle in a conventional absorption refrigeration system, such as a dual-effect absorption refrigeration system equipped with multiple generators, the first step is to
As shown in the figure, the cooling cycle and heating cycle can be performed by operating valves in the piping. In the heating cycle of this configuration example, heat is generated in the high temperature generator and heat is exchanged with the absorption solution in the low temperature generator. Heating operation is performed while the condensed cold soot liquid and the refrigerant liquid generated in the low-temperature generator and condensed in the condenser are mixed into the absorption solution at or near the inlet of the absorption solution of the low-temperature generator.

(Hot water is taken out from the absorber and condenser.) Mixing cold soot into the low temperature generator lowers the concentration of the solution in the low temperature generator and lowers the boiling temperature of the solution under the pressure of the condenser. This results in lowering the cold soot vapor pressure in the high temperature generator, which is the heating source for the low temperature generator. Therefore, when the load is very small, or when the external fluid that cools the condenser, such as cooling water or hot water during heating, is low, the temperature of the hot water is low (at startup or when the set value of the hot water temperature is lowered). The internal pressure of the generator drops too much, making it difficult for the solution to come out of the high temperature generator. That is, when the solution circulation (inflow and outflow amount) of the high temperature generator deteriorates and the solution circulation amount decreases, the concentration range increases, the concentration at the high temperature generator outlet increases, and there is a tendency for crystal formation to occur. This is shown in the cycle diagram in Figure 2, and is also clear from Figure 3, which shows an example of the relationship between hot water outlet temperature and high temperature generator internal pressure at full load, but the decisive drawback of the conventional machine is Deterioration of solution circulation caused by a drop in the internal pressure of the high-temperature generator is caused by the concentration of the high-temperature generator increasing and concentrating, and the concentration of the low-temperature generator becoming diluted. As it progresses, it progresses more and more, and once excessive dilution occurs, there is no self-recovery ability, which is inconvenient and impedes safe driving. In addition, in order not to reduce the amount of solution circulating even when the pressure inside the high-temperature generator is low, the concentrated solution in the high-temperature generator is directly passed through the bypass without passing through either the high-temperature heat exchanger or the low-temperature heat exchanger, which have high resistance. There is also a method that allows the solution to flow into the absorber or the solution pipe line that flows into the absorber, but since the extremely high temperature solution is directly returned to the low pressure absorber, it causes flashing, noise generation, and corrosion due to cavitation. If a valve is installed in the bypass to control the flow rate of the bypass according to the ambient conditions, this valve must be of high quality and not heat resistant, making it expensive and causing many troubles due to heat.
Furthermore, in the high-temperature heat exchanger, most of the solution flows into the bypass that has already been opened on the upstream side, causing the solution to stagnate, and there is a risk of corrosion or crystal formation due to the difference in concentration of the solution.
Furthermore, during the cooling cycle, efficiency becomes extremely poor.
It had the following drawbacks.

In the present invention, a concentrated solution system from a high-temperature generator is branched after passing through a high-temperature heat exchanger, and the branched system is a solution system that flows into an absorber or an absorber without passing through a low-temperature heat exchanger. By connecting it to the high temperature generator, it eliminates the above-mentioned drawbacks of the secondary one, prevents a decrease in the circulation amount of the solution even when the pressure of the high temperature generator is low, and prevents troubles caused by an excessive increase in the concentration of the solution in the high temperature generator. In addition, it prevents flashing from occurring and prevents noise and corrosion.In high-temperature heat exchangers, the high-temperature solution does not stagnate and there is no risk of corrosion or crystallization. It is an object of the present invention to provide a dual-effect absorption air-conditioning device that can prevent crystallization without significantly reducing efficiency even during a cooling cycle. In the present invention, a solution circulation path is formed by connecting an absorber, a low-temperature generator, a high-temperature generator, a low-temperature heat exchanger, and a high-temperature heat exchanger, and a dilute solution system from the absorber to the high-temperature generator is provided. is arranged to pass through the low-temperature heat exchanger and the high-temperature heat exchanger, and the route of the concentrated solution concentrated in the high-temperature generator is routed through the high-temperature heat exchanger and then branched at a branch point. , a dual-effect absorption heating and cooling device characterized in that a branch line bypasses a low-temperature heat exchanger and is connected at a connection point to the absorber or to the solution line flowing into the absorber.

The present invention will be explained with reference to FIG. 4 in accordance with an embodiment of the present invention. In an apparatus for performing a cooling cycle and a heating cycle, which includes a mechanism that is connected to piping to constitute an absorption refrigeration cycle, and valves 8 and 9 of an air conditioning/heating switching mechanism in the piping, and which is led out from the condenser 3,
A condensate return pipe 18 entering the evaporator 4 is provided with a valve 8, and a soot liquid bypass pipe 19 having a valve 9 is provided in the return pipe 18, and the cold soot liquid bypass pipe 19 is connected to the high temperature heat exchanger 7. A line connected to the low temperature generator 2 and/or a line connected to the low temperature generator 2 is provided.

Further, the valve 9 may be a valve that can adjust the relationship as appropriate, such as a control valve.
The valve is an ON-OFF valve, etc., and is controlled to adjust the amount of soot mixed in according to the operating condition.
Thus, pipes 13, 13', 16, and 16' are provided as a system for the concentrated solution from the solution reservoir 20 of the high temperature generator 1, passing through the high temperature heat exchanger 7 and the low temperature heat exchanger 6.

After passing through the high temperature heat exchanger 7, this concentrated solution line is branched off at a branch point 26 into a branch pipe 27 forming a branch line. The branch pipe 27 is provided with a valve 28 in the middle, and its terminal end is connected at a connection point 29 to the pipe line 25, which is a solution system line flowing into the absorber 5, thereby bypassing the low temperature heat exchanger 6 and flowing into the absorber 5. There is an influx. 1' and 2' are generator tubes, 3' is a condenser tube, 4' is an evaporator tube, 5' is an absorber tube, 11 is piping, 14 is a cold soot pump, 15 is a solution pump, 17 is a valve, 21 is a cold soot vapor conduit, 22 is a pipe, 24 is a cold circulation pipe, and 25 is a nozzle.

The dilute solution from the absorber 5 is guided to the high temperature generator 1 via the low temperature heat exchanger 6 and the high temperature heat exchanger 7 by a solution pump 15, and is then exchanged with the heated side of the low temperature heat exchanger 6 in the piping 11. A pipe 12 leading to the low-temperature generator 2 from the heated side of the vessel 7 is provided so that a part of the dilute solution from the absorber 5 can be bypassed if necessary. The operation of the embodiment constructed as above will be described. When the valve 8 is opened and the valve 9 is closed, the cooling cycle is performed.

That is, the dilute solution is sent to the high temperature generator 1 via the low temperature heat exchanger 6 and high temperature heat exchanger 7 by the solution pump 15, where it is heated to a high temperature, releases soot vapor, and is concentrated to become an intermediate solution. . This solution enters the high-temperature heat exchanger 7, where its temperature is lowered by heat exchange with the dilute solution from the absorber 5, and then enters the low-temperature generator 2, where it collects the cold soot vapor previously generated in the high-temperature generator 1. The soot vapor generated in the low temperature generator 2 enters the condenser 3Z, where it is cooled by cooling water and condensed. . Further, the cold soot vapor generated in the high temperature generator 1 is also condensed by heat exchange with the solution in the low temperature generator 2 and enters the condenser 3. The refrigerant accumulated in the condenser 3 passes through the condensate return pipe 18, passes through the valve 8, and returns to the evaporator 4. The concentrated solution leaving the low temperature generator 2 passes through pipes 16 and 16', exchanges heat with the dilute solution in the low temperature heat exchanger 6, and enters the absorber 5, which is a heat transfer tube absorber with cooling water inside. It is sprayed from the nozzle 25 onto the group of tubes 5'. The sprayed concentrated solution is cooled by the cooling water and becomes a dilute solution by absorbing the evaporated refrigerant vapor in the evaporator 4. In the evaporator 4, the cold water loses heat due to evaporation of the lining medium and becomes low temperature. becomes. As described above, the dilute solution is sent to the high temperature generator 1 via the low temperature heat exchanger 6 and the high temperature heat exchanger 7 to perform a cooling cycle. Furthermore, during the heating cycle, the valve 8 is closed, the valve 9 is opened, and the medium liquid accumulated in the condenser 3 is introduced into the low temperature generator 2.

The solution leaving the low temperature generator 2 passes through the low temperature heat exchanger 6 and enters the absorber 5, where it imparts heat to the cooling water (hot water) and completes the heating cycle. In this case, the solution concentration in the low temperature generator 2 becomes low, and due to the decrease in concentration, the generated vapor pressure becomes high, and the condensation temperature increases. Therefore, the cooling water (hot water) coming out of the condenser 3
The temperature will increase and it can be used for heating, etc. Therefore, when the pressure inside the high-temperature generator 1 is low, especially during heating, if the valve 28 is opened and the branch pipe 27 is passed through, the concentrated solution leaving the high-temperature heat exchanger 7 will have a low resistance and a low pressure. Connection point 29
The solution flows through the branch pipe 27 connected to the , and the necessary solution circulation amount can be ensured. Therefore, it is possible to prevent an excessive increase in concentration due to a decrease in the amount of solution circulation, and to prevent crystallization caused by this. In addition, the high temperature concentrated solution from the high temperature generator 1 passes through the high temperature heat exchanger 7 and has a relatively low temperature, so even if it is led to the low pressure absorber 5, no flushing occurs and noise and corrosion are prevented. The valve 28 does not need to have high heat resistance requirements, making it inexpensive and causing fewer troubles.Furthermore, since the required amount of solution always flows in the high-temperature heat exchanger 7, corrosion due to stagnation or There is no risk of crystal formation. Furthermore, since heat is recovered in the high temperature heat exchanger 7 even during the cooling cycle, crystallization can be prevented without significantly reducing efficiency. Valve 2 of branch pipe 27
8 is not necessary.

Further, this valve 28 may be a manual valve or an automatic valve. This valve 2
The control in step 8 can be effected automatically, manually, continuously, intermittent, or on/off in various cases as described below. (1) If the internal pressure of the high temperature generator is low during both cooling and heating, or if you want to operate at low pressure, the internal pressure can be detected directly or indirectly by the temperature of a specific part of the cycle, and the branch line can be Make use of it.

(D) During the heating cycle, the internal pressure of the high temperature generator is generally low, so make use of the branch system. (m) When the cooling, heating, and air-conditioning cycles are started, the internal pressure of the high-temperature generator has not yet risen sufficiently. Make use of it.

(W) Utilize the branch line as a solution dilution cycle when the heating and cooling equipment is stopped.

(V) When the temperature of the cooling water or hot water is low, the internal pressure of the high pressure generator decreases, so the branch system can be utilized by detecting the temperature.

(Town) In the case of a combination of multiple items above. In addition, valves 8 and 9 are used to mix cold soot into the solution for the heating cycle.
, pipes 18 and 19, the valves 8 and 9 may be one three-way valve, or other connection configurations in which one may be omitted may be selected. In FIG. 4, a pipe 12 leads a portion of the dilute solution to the low temperature generator 2, and the concentration within the low temperature generator 2 decreases, the boiling temperature of the solution decreases, and the pressure within the high temperature generator 1 decreases. It is effective to lower the pressure inside the high-temperature generator 1 when everyone is loaded or when the cooling water temperature is high, and it is also preferable by law to keep the internal pressure of the high-temperature generator 1 below atmospheric pressure. On the other hand, if the internal pressure is low, the internal pressure may drop too much and cause a problem in solution circulation. This is particularly effective for devices. FIG. 5 shows another embodiment in which the connection point 29 is provided immediately below the absorber 5, and the connection point 29 is provided at a lower position than the branch point 26, so that the internal pressure of the high pressure generator 1 In addition to the differential pressure between the absorber 5 and the internal pressure of the absorber 5, a position head is also used to ensure smooth circulation of the solution.

FIG. 6 shows another embodiment in which connection points 29 are provided along three overflow lines connecting the low temperature generator 2 and the absorber 5.

During the noren cycle, the pressure difference between the low-temperature generator and the absorber is generally large, making it easy for gas bypass to occur. Since the noise becomes loud when a gas bypass occurs, a valve is normally provided in the overflow line 30 and this valve is closed during heating, but as in this embodiment, the connection point 29 is connected to the overflow line 30' to allow the solution to flow. Gas bypass can be prevented. Figure 7 shows another embodiment in which the refrigerant vapor from the high-temperature generator is guided to the absorber and evaporator, and the solution is circulated. In general, the internal pressure of the high-pressure generator 1 that performs the heating cycle while feeding is likely to be lower than that of other systems, and in this case, there is a risk that the circulation of the absorption solution cycle will deteriorate; however, in this example, By providing a bypass using the branch pipe 26, the cycle of the absorption solution can be ensured, which is particularly effective.

In the present invention, a solution circulation path is formed by connecting an absorber, a low temperature generator, a high temperature generator, a low temperature heat exchanger, and a high temperature heat exchanger,
A system for a dilute solution from the absorber to the high temperature generator is arranged to pass through the low temperature heat exchanger and the high temperature heat exchanger, and a system for the concentrated solution concentrated in the high temperature generator is arranged to pass through the low temperature heat exchanger and the high temperature heat exchanger. The solution is routed through a high temperature heat exchanger and then branches off at a branch point, and the branch line bypasses the low temperature heat exchanger and is connected to the absorber or the solution line flowing into the absorber at the connection point. This not only prevents the solution concentration in the high temperature generator from becoming excessive even when the internal pressure of the high temperature generator is low or when it is desired to operate in a low state, preventing the danger of crystal formation, but also suppressing flashing. The valves in the branch system do not require a high level of heat resistance, and troubles caused by high heat are also prevented.Furthermore, there is no stagnation of high temperature and high concentration solutions in the high temperature heat exchanger, and corrosion and crystal formation are avoided. It is possible to provide a dual-effect absorption air-conditioning device that can prevent crystallization without causing any risk of crystallization and without significantly reducing efficiency during the cooling cycle, and has extremely great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a system explanatory diagram of a subordinate example, and FIGS. 2A and 2B are cycle diagrams showing the relationship between pressure and concentration of the example in FIG. 1, where A is a case where hot water is high and B is a case where hot water is low. Figure 3 is a relationship diagram between high temperature generator internal pressure and hot water outlet temperature.
FIGS. 4 to 7 are system diagrams of different embodiments of the present invention. 1... High temperature generator, 2... Low temperature generator, 1', 2'... Generator tube, 3...
... Condenser, 3' ... Condenser tube, 4.
...Evaporator, 4'...Evaporator tube,
5...Absorber, 5'...Absorber tube, 6...Low temperature heat exchanger, 7...High temperature heat exchanger, 8, 9...Valve , 10...detector, 11, 12, 1
3,13'...Piping, 14...Cold soot pump, 15...Solution pump, 16,16'...
... Piping, 17 ... Valve, 18 ... Condensate return pipe, 19 ... Refrigerant liquid bypass pipe, 2
0...Solution reservoir, 21...Soot vapor conduit, 22...Piping, 24...Refrigerant circulation pipe, 25... Nozzle, 26... Branch point, 27... Branch pipe, 28... Valve, 29...
... Connection point, 30 ... Overflow line. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Strategy? figure

Claims (1)

[Claims] 1. Absorber, low temperature generator, high temperature generator, low temperature heat exchanger,
A solution circulation path is formed by connecting a high-temperature heat exchanger, and a dilute solution path from the absorber to the high-temperature generator is arranged to pass through the low-temperature heat exchanger and the high-temperature heat exchanger, A line for the concentrated solution concentrated in the high temperature generator passes through the high temperature heat exchanger and is then branched off at a branch point, and the branch line bypasses the low temperature heat exchanger and is connected to the absorber or the absorber. A dual-effect absorption heating and cooling device, characterized in that it is connected at a connection point to a solution line flowing into the system. 2. The device according to claim 1, further comprising a valve in the branch line. 3. The device according to claim 1 or 2, wherein the connection point is located lower than the branch point of the branch line. 4. The device according to claim 1, 2 or 3, wherein the connection point is provided in an overflow line connecting the low temperature generator and the absorber.