JP2635276B2 - Absorption type cold / hot water unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type chilled and heated water unit for general air conditioning, and more particularly to an absorption chilled and heated water unit capable of automatic switching operation of cooling and heating and capable of individually distributed air conditioning.

[0002]

2. Description of the Related Art FIG. 3 shows an absorption cooling / heating water unit having an automatic cooling / heating switching function (hereinafter referred to as an absorption cooling / heating water unit).
First, the cooling / heating operation cycle is as follows. During the cooling operation, the cooling / heating switching automatic valves 43 and 44 are closed by the switching operation electric signal. Further, the cooling water system piping 40 is filled with cooling water, with the cooling water system automatic draining valve 48 and the air bleeding automatic valve 49 both closed and the cooling water supply automatic valve 47 opened. By the way, the absorber 30
Solution diluted by the refrigerant (water) with the solution pump 31
Low temperature solution heat exchanger 32, high temperature solution heat exchanger 33
After that, the refrigerant is sent to the high-temperature regenerator 34, where it is heated and the refrigerant is evaporated and concentrated. Further, the low-temperature solution heat exchanger 32
The dilute solution branched from the outlet of the above and sent to the low temperature regenerator 35 exchanges heat with the refrigerant vapor generated from the high temperature regenerator 34 to generate and concentrate the secondary refrigerant vapor. High temperature regenerator 34
The concentrated solution concentrated in is passed through a high-temperature solution heat exchanger 33,
The solution concentrated in the low-temperature regenerator 35 passes through the low-temperature solution heat exchanger 32, and sensible heat is given to the dilute solution by the solution heat exchangers 32 and 33, and then dispersed in the absorber 30. On the other hand, each of the refrigerant vapors generated in the high-temperature regenerator 34 and the low-temperature regenerator 35 is condensed in the low-temperature regenerator 35 and the condenser 36, flows down into the evaporator 37 as a refrigerant liquid. And
The refrigerant is sprayed into the evaporator by the refrigerant spray pump 38, obtains heat of evaporation from the cold / hot water in the cold / hot water return pipe 4, evaporates, and passes through the vapor passage connecting the evaporator 37 and the absorber 30 to the inside of the absorber. Is absorbed into the concentrated solution. The heat of condensation of the refrigerant generated in the absorber 30 is removed by the cooling water circulating through the cooling water pipe 40. Note that the cooling water circulates through the condenser 36 via the absorber 30 to remove the condensation heat of the refrigerant vapor generated in the low-temperature regenerator 35, and then cools the cooling tower 42.
Then, the heat of condensation is released to the outside air and cooled. The circulation of the cooling water is performed by a circulation pump 41. Since the check valve 52 is provided on the discharge side of the cooling water pump 41, the cooling / heating water unit stops in the cooling operation mode,
Even if the cooling water pump stops, the cooling water on the secondary side of the check valve 52 does not flow back to the cooling tower.

In the heating operation cycle, the cooling / heating switching automatic valve 4
3, 44 are opened. The automatic water supply valve of the cooling water system is closed, and the automatic drainage valve 48 is opened, and is closed after drainage of the cooling water is completed. The automatic air bleed valve 49 is closed. Now, the refrigerant vapor generated in the high-temperature regenerator 34 flows into the evaporator 37 via the valve 43 without passing through the low-temperature regenerator 35, and heats the cold / hot water to the cold / hot water return pipe 4 to condense. I do. The condensed refrigerant liquid is sent to the absorber 30 via the cooling / heating switching valve 44 by the refrigerant spray pump 38, where it dilutes the concentrated solution sent from the high temperature regenerator 34 and the low temperature regenerator 35 and sprayed in the absorber. Make a dilute solution and again use solution pump 3
At 1, it is sent to the high temperature regenerator 34 and the low temperature regenerator 35. In this heating cycle, the cooling water circulation pump 41 is stopped, and no heat exchange is performed in the absorber 30 and the condenser 36,
The operation of the cooling tower 42 is also stopped.
The automatic bleeding device 45 is for discharging non-condensable gas in the machine maintained at a pressure lower than the atmospheric pressure, and operates continuously or periodically mainly at the time of switching from the heating to the cooling cycle or at the time of the cooling cycle. To prevent a decrease in cooling capacity.

[0004]

When the cooling / heating cycle of such an absorption-type cooling / heating water unit is switched, the cooling water is supplied each time (when switching from the heating to the cooling cycle).
Or drainage (when switching from cooling cycle to heating cycle)
The switching operation requires a long time, and the cycle switching cannot be performed immediately. In addition, when the number of switching of the cycle is increased in the middle period of spring and autumn, there is a disadvantage that the amount of drainage of cooling water increases and water is wasted.

[0005] These drawbacks can be solved by always keeping the cooling water in the path irrespective of cooling or heating. However, if the cooling water is always kept in the path, some problems occur. That is, at the time of switching from heating to the cooling cycle, the cooling water staying in the absorber and the condenser in the heating operation is heated by the high-temperature refrigerant vapor and becomes high-temperature water. When the cooling water pump is operated, the high-temperature water is extruded as it is and flows down to the cooling tower, and there is a possibility that the plastic-molded Raschig ring 51 and the like in the cooling tower may be heated and deformed. And the freezing of cooling water.

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems by enabling constant storage of cooling water, which is a factor of prolonging the cooling / heating switching time and cooling at the time of switching which leads to waste of water. An object of the present invention is to provide an absorption-type cold / hot water unit that makes supply and discharge of water almost unnecessary.

[0007]

According to the present invention, when the cooling / heating operation mode is switched, only the inside of the cooling water system piping, the inside of the heat transfer pipe of the condenser and the absorber and the water chamber are filled and drained, and the cooling tower is operated. Water filling and draining operations were not performed (claim 1).

Further, according to the present invention, the cooling water pipe returning from the condenser to the cooling tower is once lowered to a level lower than the cooling water level in the cooling tower and then raised to form a U-shaped pipe to form a U-shaped pipe. The cooling water was sprayed, the cooling water pump was not provided with a check valve on the discharge side, an automatic air vent valve was provided at the top of the cooling water piping system, and the operation mode was switched from cooling to heating. At this time, the automatic air release valve was opened to drain water only in the cooling water system piping, the heat transfer tubes of the condenser and the absorber, and the water chamber (claim 2).

Further, according to the present invention, a temperature detecting means for detecting a cooling water temperature is provided in a cooling tower or in a lower cooling water pipe, and when the detected temperature of the detecting means falls below a predetermined value, the lower cooling water pipe is provided. The cooling water is heated by a band heater installed in the device (claim 3).

Further, according to the present invention, a water level detecting means for detecting a water level in the cooling water piping system is provided, and when the water level detected by the water level detecting means is equal to or lower than a predetermined value at the start of the cooling operation, the cooling water pump is operated. The vehicle is controlled not to run (claim 4).

Further, according to the present invention, an automatic drain valve is provided independently on the secondary side of the check valve on the discharge side of the cooling water pump,
When the operation mode is switched from cooling to heating, the automatic drain valve is opened to drain water only in the cooling water system piping, the condenser, the heat transfer pipe of the absorber, and the water chamber (claim) Item 5).

Conventionally, as a treatment of the cooling water at the time of switching the cooling / heating cycle, the cooling water is drained at the time of heating. However, according to the present invention, the cooling water / cooling operation mode switching and the cooling water system piping and the condenser are performed. In addition, water filling and draining operations are performed only in the heat transfer tubes and the water chamber of the absorber, and water filling and draining operations in the cooling tower are not performed. This makes it unnecessary to supply and drain water by manual operation of the cooling tower (claim 1).

[0013]

Further, according to the present invention, the cooling water pipe returning from the condenser to the cooling tower is once lowered to a level lower than the level of the cooling water in the cooling tower, and then raised to raise the cooling water pipe.
A cooling pipe is formed and disposed so as to spray cooling water in the cooling tower. A check valve is not provided on the discharge side of the cooling water pump, and an automatic air vent valve is provided at the top of the cooling water piping system.
As a result, even if the cooling / heating water unit is stopped and the cooling water pump is stopped in the cooling operation mode, the cooling water is mostly supplied to the cooling tower by the action of the U-shaped pipe even if there is no check valve on the discharge side of the cooling water pump. Do not flow back to When switching the operation mode from cooling to heating, open the air venting automatic valve at the top of the cooling water piping system and introduce air into the upper part of the cooling water piping, because there is no check valve on the discharge side of the cooling water pump, Most of the cooling water piping, the cooling water in the heat transfer tubes of the condenser and the absorber, and the cooling water in the water chamber flow into the cooling tower, and are discharged from the overflow port of the cooling tower. As a result, only the majority of the cooling water pipes, the heat transfer pipes of the condenser and the absorber, and the water chamber are drained, and the cooling water in the cooling tower remains in the cooling tower. Therefore, at the time of switching from the heating to the cooling cycle, the high-temperature water staying in the absorber and the condenser during the heating operation does not return to the cooling tower and the cooling tower is not deformed by the thermal shock (claim 2).

Further, according to the present invention, the cooling water temperature detecting means provided in the cooling tower or in the lower cooling water pipe,
When detecting a drop in the cooling water temperature, a band heater installed in the lower cooling water pipe is energized to heat the cooling water. The heated and heated cooling water circulates with the cooling water in the cooling tower by convection to prevent freezing of the cooling water in winter. When the temperature rises to a predetermined temperature, the above-mentioned temperature detecting means operates to prevent the band heater from being energized (claim 3).

Further, in the present invention, when the cooling water pump is operated after switching from heating to cooling, the level of the cooling water in the cooling tower drops, and the cooling water is automatically replenished from the ball tap valve, and the cooling water is switched from cooling to heating. When switching, replenish the cooling water drained from the overflow port. During the operation of the cooling water pump, when the detected water level of the cooling water level detecting means provided for protecting the cooling water pump is equal to or lower than a predetermined value, the operation of the cooling water pump is interlocked to prevent idle operation. (Claim 4).

[0016]

FIG. 1 shows an embodiment of the present invention.
3 denote the same components. For the cooling water piping system, the water supply to the cooling tower 42 is
The water level is controlled by the ball tap valve 50 from the water supply valve 59 so that the water level in the storage tank of the cooling tower 42 is always constant throughout the four seasons. Thus, the inside of the storage tank of the cooling tower is always maintained in a full state. Also, the cooling water pipe that reaches the cooling tower 42 via the absorber 30 and the condenser 36 once falls below the level of the cooling water in the cooling tower, and then rises upward to form a U-shaped pipe to form a cooling tower. It is arranged to spray cooling water inside. There is no check valve on the discharge side of the cooling water pump 41, and an automatic air vent valve 49 is provided at the top of the cooling water pipe. Thereby, in the cooling operation mode,
Even if the cooling / heating water unit is stopped and the cooling water pump 41 is stopped, the cooling water hardly flows back to the cooling tower by the action of the U-shaped tube. When the operation mode is switched from cooling to heating, the air venting automatic valve 49 at the top of the cooling water piping system is opened to introduce air into the upper part of the cooling water piping, and there is no check valve on the discharge side of the cooling water pump 41. Therefore, cooling water piping 4
Most of 0, cooling water in the heat transfer tubes of the condenser 36 and the absorber 30 and in the water chamber flows into the cooling tower 42 and is drained from the overflow port 64 of the cooling tower.
If the cooling water stays in the absorber and the condenser,
When the cooling operation is immediately switched to the cooling operation after the heating operation, the cooling water in the absorber 30 and the condenser 36 is hot water of about 70 ° C., and this high-temperature water falls on the Raschig ring 51 and deforms. However, in the embodiment of the present invention, even if all the cooling water in the cooling water system is not drained, since there is no cooling water staying in the absorber and the condenser, the operation from the heating to the cooling operation is performed. When switching to, hot water from the condenser does not return to the cooling tower.

Next, as a measure to prevent the cooling water piping system from freezing in winter, a cooling water temperature detecting means 54 is provided in the cooling tower, whereby when the cooling water temperature falls below a preset temperature, the lower cooling water This is performed by heating the cooling water by energizing the band heater 61 disposed in the pipe. The cooling water heated and heated by the band heater circulates with the cooling water in the cooling tower 42 by convection, and the entire cooling water is heated to prevent freezing. When the temperature of the cooling water in the cooling tower 42 rises to a predetermined temperature, the above-mentioned temperature detecting means 54 operates, and the energization of the band heater 61 is stopped.

Next, when the cooling water pump 41 is operated after the operation mode is switched from heating to cooling, the water level of the cooling water in the cooling tower 42 drops, and the ball tap valve 50
The cooling water is supplied more automatically, and the amount of the cooling water discharged from the overflow port 64 when the air conditioner is switched from cooling to heating is replenished. During operation of the cooling water pump 41, a cooling water level detection level switch 62 is provided in the cooling tower to protect the cooling water pump.
The operation 1 is interlocked to prevent idling.

FIG. 2 shows another embodiment of the present invention. In this embodiment, in addition to the configuration of the conventional example of FIG. 3, a secondary side of a check valve 52 on the discharge side of the cooling water pump 41 is provided.
Independently, an automatic draining valve 65 is provided, and when the operation mode is switched from cooling to heating, only the automatic draining valve is opened. The automatic air valve 49 remains closed. Thereby, water is drained only in the cooling water system pipes, the heat transfer tubes of the condenser and the absorber, and the water chamber. In this way, when the cooling / heating operation mode is switched, water is filled and drained only in the cooling water system piping, the heat transfer tubes of the condenser and the absorber, and the water chamber, and the water filling and draining operations in the cooling tower are performed. I can't. As described above, according to the present invention, there is provided an easy-to-use absorption-type cooling / heating water unit that has a short switching time of the heating / cooling cycle and can save water.

[0020]

According to the present invention, it is possible to effectively prevent the cooling tower from being damaged by the high-temperature cooling water at the time of switching from heating to cooling, and to prevent the cooling water from freezing in winter, and to constantly store the cooling water. As a result, since the operation of supplying and draining the cooling water is not required, the time required for switching the cooling / heating cycle is reduced, and an easy-to-use absorption-type cold / hot water unit is provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an absorption-type cold / hot water unit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an absorption-type cold / hot water unit according to another embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional absorption-type cold / hot water unit.

[Explanation of symbols]

 41 Cooling pump 42 Cooling tower 43 Cooling / heating switching automatic valve 44 Cooling / heating switching automatic valve 47 Automatic water supply valve 48 Automatic drainage valve 49 Automatic air release valve 50 Ball tap valve 51 Raschig ring 52 Check valve 54 Cooling water temperature detecting means 60 Cooling water drainage valve 61 Band heater 62 Level switch 64 Overflow port 65 Automatic drain valve

Claims (4)

(57) [Claims] A refrigerant vapor for cooling or heating cold and hot water in an evaporator is absorbed by a solution in an absorber, and a refrigerant vapor is separated from a dilute solution having absorbed the refrigerant vapor in a regenerator. Refrigerant vapor condensed by a condenser,
This is returned to the evaporator again, and the cooling water obtained by radiating the cooling water from the condenser with the cooling tower and lowering the temperature is cooled by the circulation pipe and the cooling water circulation pump provided in the middle thereof. In the absorption chiller / heater unit with an automatic cooling / heating switching function that can switch the cooling or heating operation mode by an external signal, return to the cooling tower from the condenser. The cooling water pipe is once lowered to a level lower than the level of the cooling water in the cooling tower, and then raised to form a U-shaped pipe to disperse the cooling water in the cooling tower. There is no check valve on the discharge side of the pump, and an automatic air release valve is provided at the top of the cooling water piping system, and the automatic air release valve is opened when the operation mode is switched from cooling to heating An absorption type cold / hot water unit characterized in that water is drained only in a cooling water system pipe, a heat transfer pipe of a condenser and an absorber, and a water chamber. 2. A temperature detecting means for detecting a cooling water temperature is provided in the cooling tower or in a lower cooling water pipe, and when the temperature detected by the detecting means falls below a predetermined value, the cooling water pipe is installed in the lower cooling water pipe. The absorption type cold / hot water unit according to claim 1, wherein the cooling water is heated by a band heater. 3. A water level detecting means for detecting a water level in a cooling water piping system is provided. When the water level detected by the water level detecting means at the start of cooling operation is lower than a predetermined value, the cooling water pump is controlled not to operate. The absorption type cold / hot water unit according to claim 1, wherein 4. A refrigerant vapor for cooling or heating cold and hot water in the evaporator is absorbed by a solution in the absorber, and the refrigerant vapor is separated from the dilute solution having absorbed the refrigerant vapor in a regenerator. Refrigerant vapor condensed by a condenser,
This is returned to the evaporator again, and the cooling water from the condenser is radiated by the cooling tower to cool down, and the cooling water obtained by cooling is circulated through the cooling water circulation pump into the absorber and condenser for cooling. In an absorption type cooling / heating water unit with an automatic cooling / heating switching function capable of switching the cooling or heating operation mode by an external signal, on the secondary side of a check valve on the cooling water pump discharge side, Independently, an automatic drain valve is provided, and when the operation mode is switched from cooling to heating, the automatic drain valve is opened to open the cooling water system piping, and the condenser, the heat transfer pipe of the absorber and An absorption-type cold / hot water unit characterized by draining water only in the water chamber.