JP3407182B2 - Absorption type cold heat generator - 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 chiller-heater, and more particularly to an absorption-type cold heat generator using a secondary refrigerant that changes phase.

[0002]

2. Description of the Related Art In recent years, a secondary refrigerant (hereinafter, also simply referred to as "refrigerant") has been devised to increase the amount of heat transfer per unit flow rate by causing a phase change. FIG. 3 shows an example of such a configuration. An absorption chiller-heater that generates cold heat and a cooling tower (cooling tower) 21 that is connected to the absorption chiller-heater by cooling water pipes 40 and 41 to cool the cooling water.
And a fan motor 23 which is installed in the cooling tower 21 and is driven according to the temperature of the stored water detected by the temperature sensor (CTS sensor) 22 in the water tank, and a cooling water pipe 41 which absorbs the cooling water from the cooling tower 21. A cooling water pump 12 which circulates to the condenser 3 and the condenser 2, and an evaporator 4 which is connected to the evaporator 4 by a refrigerant liquid pipe 50 and a refrigerant gas pipe 51 and is arranged in an air-conditioned space to exchange heat with the air in the space. Indoor unit 5
Refrigerant pump that circulates the secondary refrigerants 2, 53, and the secondary refrigerant that is interposed in the refrigerant liquid pipe 50 and filled in the refrigerant liquid pipe 50 and the refrigerant gas pipe 51 between the evaporator 4 and the indoor units 52, 53 for air conditioning. 5
And 7 are included. The cooling circuit is formed by the cooling tower 21 and the cooling water pump 12 and the like, and the refrigerant circuit is formed by the indoor units 52 and 53, the refrigerant pump 57 and the like.

The refrigerant liquid pipe 50 and the refrigerant gas pipe 51 are connected to the lower end and the upper end of the evaporation coil of the evaporator 4, respectively. The other ends of the refrigerant liquid pipe 50 and the refrigerant gas pipe 51 are branched by the number of the indoor units 52 and 53 arranged below the evaporation coil, and the branched end of the refrigerant liquid pipe 50 is the indoor unit 5
2 and 53 are connected to the lower inlets of the heat exchangers respectively installed therein via expansion valves 54 and 55, and the branch ends of the refrigerant gas pipes 51 are respectively connected to the upper outlets of the heat exchangers. A refrigerant liquid temperature sensor (CRI sensor) 17 for detecting the temperature of the secondary refrigerant and outputting it as an electric signal to a control box (control means) 59 near the connection portion of the refrigerant liquid pipe 50 with the evaporation coil, a cooling water pump. A cooling water temperature sensor (CT1 sensor) 19 near the outlet of 12, an evaporator temperature sensor (LT sensor) 16 and the like above the evaporator 4, and a refrigerant gas temperature sensor near the upper end of the evaporation coil of the refrigerant gas pipe 51. The (CRO sensor) 18 and the refrigerant solenoid valve 20 controlled by the control box 59 according to the temperature detected by the refrigerant gas temperature sensor 18 are mounted.

In contrast to the indoor units 52 and 53, the absorption chiller-heater is usually called a hot water-fired multi-unit outdoor unit having a cooling circuit, and heats a dilute solution with heat of a heat medium to generate a concentrated solution and a refrigerant vapor. Regenerator 1 that separates into two parts, a condenser 2 that cools the separated refrigerant vapor and condenses and liquefies it to produce a liquid refrigerant, and the liquid refrigerant created in condenser 2 drops and evaporates on an evaporation coil equipped with it. An evaporator 4 that cools the secondary refrigerant in the coil, an absorber 3 that absorbs the refrigerant vapor evaporated in the evaporator 4 into a concentrated solution to produce a dilute solution, and the dilute solution is pressurized to heat the heat exchanger 5. The solution circulation pump 7 that feeds into the regenerator 1 via the fluid side, the conduit 6 that connects the bottom of the condenser 2 and the evaporator 4, and the heating fluid outlet side of the heat exchanger 5 are connected to the upper portion of the absorber 3. Concentrated solution pipe 8A, and a solution bypass valve 8 connecting the concentrated solution pipe 8A and the lower part of the absorber 3 , Evaporator temperature sensor 1 for detecting the temperature (evaporator temperature) of the refrigerant in the refrigerant distributor 6A evaporator 4
6 and an antifreezing valve 9 provided on a pipe line connecting the discharge side of the solution circulation pump 7 to the refrigerant distributor 6A.

Further, a cooling water coil is installed in each of the absorber 3 and the condenser 2, and an outlet of the cooling water coil of the absorber 3 is connected to an inlet of the cooling water coil of the condenser 2.
The inlet of the cooling water coil of the absorber 3 is connected to the cooling water pipe 41, and the outlet of the cooling water coil of the condenser 2 is connected to the cooling water pipe 40. The refrigerant liquid pipe 50 is connected to the entrance side of the evaporation coil of the evaporator 4, the refrigerant gas pipe 51 is connected to the exit side of the evaporation coil of the evaporator 4, and the secondary refrigerant is provided near the exit of the evaporation coil of the evaporator 4. A cold water outlet temperature sensor 17 for detecting the temperature of the is attached.

The refrigerant liquid pipe 50 is connected to the indoor units 52 and 53 on the way.
There is a portion arranged at a lower position than the above, and a refrigerant pump 57 that pressurizes the refrigerant liquid and sends it to the evaporation coil is attached thereto. During the heating operation, the outlet side of the check valve 58 provided on the discharge side of the refrigerant pump 57 and the suction side of the refrigerant pump 57 are connected via the cooling / heating switching valve 56.
Then, as a secondary refrigerant that changes phase, for example, HFC134
The refrigerant liquid pipe 50 is filled with a.

The operation of the air conditioner shown in FIG. 3 during cooling is as follows. The cooling / heating switching valve 56 is opened during cooling. The refrigerant vapor (HFC134a) is cooled and condensed in the evaporation coil of the evaporator 4 to become a refrigerant liquid, which flows downward in the refrigerant liquid pipe 50 due to gravity, and through the expansion valves 54 and 55, heat exchange between the indoor units 52 and 53. Flows into the vessel. The refrigerant liquid flowing into the heat exchanger evaporates by taking the heat of the air in the air-conditioned space,
It becomes the refrigerant gas and goes up through the refrigerant gas pipe 51 to rise to the evaporator 4
Flowing into the evaporation coil of. Since the outdoor unit is operated in the cooling mode, the evaporation coil of the evaporator 4 is cooled by the evaporation of the liquid refrigerant dropped on its surface, and the refrigerant gas flowing into the evaporation coil is condensed and liquefied. Due to this condensation and liquefaction, the pressure inside the evaporation coil decreases, and the indoor units 52, 53
The refrigerant gas evaporated in the heat exchanger is sucked into the evaporator 4. Since the refrigerant liquid condensed and liquefied inside the evaporation coil flows into the indoor units 52 and 53 by gravity, the refrigerant during cooling naturally circulates, and it is not necessary to drive the refrigerant by the refrigerant pump 57.

When the cooling operation is started, as described above,
The pressure inside the evaporation coil decreases, and the saturated refrigerant gas in the refrigerant gas pipe 51 flows into the evaporation coil due to the pressure difference. The refrigerant liquid condensed and generated in the evaporation coil is the refrigerant liquid pipe 5
The head (liquid column) of the refrigerant liquid rises as it flows down in 0 by its own weight. In order for the natural circulation of the refrigerant to be established, it is sufficient that (refrigerant liquid head-refrigerant gas head) is equal to or greater than the total pressure loss of the refrigerant circulation path. That is, the natural circulation of the refrigerant is not started until the liquid head satisfying this relationship is formed. This means that the heat load supplied to the evaporator 4 at the start of the cooling operation is small.

During heating, the cooling / heating switching valve 56 is closed. The refrigerant liquid is heated by the evaporation coil of the evaporator 4 to become a refrigerant gas, flows through the refrigerant gas pipe 51 downward, and flows into the heat exchanger of each indoor unit 52, 53. The refrigerant gas flowing into the heat exchanger is deprived of heat by the air in the air-conditioned space to be condensed and liquefied, and becomes a refrigerant liquid, which flows downward through the refrigerant liquid pipe 50 and flows into the refrigerant pump 57 inlet side. The refrigerant liquid is pressurized by the refrigerant pump 57, flows into the evaporation coil of the evaporator 4, and repeats the above cycle. At this time, the outdoor unit is operated in the heating mode, the high temperature concentrated solution separated by the regenerator 1 is guided to the evaporator 4, and the evaporation coil is heated by this heat.

In such a device, a cooling water inlet temperature at which the cooling operation can be started (starting the cooling operation) is generally set for winter cooling or the like, and protection is performed at a temperature lower than this set temperature, for example, 8 ° C. or lower. The function is activated and air conditioning cannot be performed. In the warm water-fired natural multi-system, when the cooling water inlet temperature is low, for example, 8 ° C. or less, when the cooling operation is started, it takes time until the solution temperature and the cooling water temperature rise, and the cooling start-up becomes slow. Will end up. This was particularly noticeable when the heat medium temperature was raised above room temperature.

[0011]

In the conventional absorption-type cold heat generator, the cooling water inlet temperature at which the cooling operation can be started is set to, for example, 8 ° C., and the cooling operation is performed below this set temperature. Once started, it takes time for the temperature of the solution and the temperature of the cooling water to rise, and the cooling rise is delayed. In particular, there is a problem that becomes remarkable when the temperature of the heating medium is raised from room temperature.

An object of the present invention is to provide an absorption type cold heat generating device which can smoothly start up the cooling operation at the time of low temperature cooling water.

[0013]

In order to achieve the above-mentioned object, the absorption type cold heat generating device according to the present invention heats the dilute solution fed from the absorber by the regenerator to form a refrigerant vapor and a concentrated solution. An absorption chiller / heater that separates and circulates the concentrated solution through the cooling / heating switching valve and / or the solution bypass valve to the absorber and the refrigerant vapor to the condenser and evaporator, and cooling water to the condenser via the absorber A cooling circuit that circulates with a cooling water pump,
In an absorption-type cold heat generating device, which comprises at least a control means for controlling the cooling / heating switching valve, and a refrigerant circuit for circulating a phase change refrigerant between the evaporator and at least one indoor unit,
When the cooling water inlet temperature at the start of the cooling operation is low, the control means controls the operation time for a long time according to the low temperature to perform forced heating.

The control means is arranged so that the inlet temperature of the cooling water is 8
When the temperature is between 15 ° C and 15 ° C, the cooling / heating switching valve is opened for 10 minutes, the solution bypass valve is opened, the cooling water pump is delayed for 5 minutes for forced heating for 10 minutes, and the cooling water inlet temperature is 5 minutes. When the temperature is between 8 ° C and 8 ° C, the cooling / heating switching valve is opened for 15 minutes, the solution bypass valve is opened, the cooling water pump is delayed for 10 minutes, and forced heating is performed for 15 minutes. The configuration may be such that the temperature is raised to.

According to the present invention, cooling start-up is accelerated during low-temperature cooling water, and if the cooling water inlet temperature is 5 ° C. or higher, cooling can be started even in winter.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. As shown in FIGS. 1, 2 and 3, the dilute solution is fed from the absorber 3 by the solution circulation pump 7, and the dilute solution is heated by the heat medium in the regenerator 1 and separated into the refrigerant vapor and the concentrated solution. Then, the concentrated solution is circulated to the absorber 3 through the solution bypass valve (SV9) 8 and / or the cooling / heating switching valve (CV) 10, and the refrigerant vapor is circulated to the condenser 2 and the evaporator 3 and , A cooling circuit including a cooling tower 21 in which cooling water is circulated to a condenser 2 via an absorber 3 by a cooling water pump (P2) 12, and a control means (control box) for controlling at least the cooling / heating switching valve 10.
59, the evaporator 4 and at least one indoor unit 52, 53
And a refrigerant circuit that circulates a phase-change refrigerant between the control unit 59 and the control unit 59. The control unit 59 controls the cooling water inlet temperature at the start of the cooling operation to be a low temperature close to the set temperature at which the cooling operation can be started. At this time, the operating time is controlled to be long according to the low temperature to perform forced heating.

When the inlet temperature of the cooling water is 8 ° C to 15 ° C, the control means 59 opens the cooling / heating switching valve 10 for 10 minutes and the solution bypass valve 8 and delays the cooling water pump 12 after 5 minutes. When the cooling water heating valve 10 is operated to perform forced heating for 10 minutes and the inlet temperature of the cooling water is 5 ° C. to 8 ° C., the cooling / heating switching valve 10 is opened for 15 minutes, the solution bypass valve 8 is opened, and the cooling water pump 12 is turned on. After a minute, the operation is delayed to perform forced heating for 15 minutes to raise the cooling water inlet temperature to 15 ° C. or higher.

That is, when the cooling operation is started, the cooling water inlet temperature is detected by the CTI sensor 19 and input to the control box 59, and the control box 59 outputs the cooling water pump 12, the cooling / heating switching valve 10 and the solution bypass valve 8 as follows. It is characterized by such a control.

The operation of the present embodiment will be described. When the cooling water inlet temperature is 15 ° C or higher, the cooling operation starts as usual. When the cooling water inlet temperature is 8 to 15 ° C., the cooling / heating switching valve 10 is opened for a predetermined time of 10 minutes to prevent the concentrated solution from flowing into the lower part of the absorber coil so as not to be cooled and forced heating operation for 10 minutes (or Perform preheating operation). At this time, the cooling water pump 12 is delayed after 5 minutes so that the flow of the cooling water into the absorber coil is delayed for a predetermined time, and the solution bypass valve 8 is opened (ON). After the forced heating operation for 10 minutes, if the cooling water inlet temperature is 15 ° C or higher, the cooling / heating switching valve 1
0 is closed, and the cooling water pump 12 continues to operate (ON). The solution bypass valve 8 has a cooling water inlet temperature of 20 ° C.
With the above, it is closed (OFF) and opened (ON) when the cooling water inlet temperature is 15 ° C or higher.

Similarly, when the cooling water inlet temperature is 5 to 8 ° C., the cooling / heating switching valve 10 is opened for 15 minutes, and the cooling water pump 12 is delayed after 10 minutes. When the cooling water inlet temperature is 5 ° C. or lower, the cooling operation is stopped and the low cooling water abnormality alarm is output. Normally, when performing a cooling operation in the winter type and in the interim period for a pack type (integrated cooling tower), it is common to control the cooling water temperature by installing an antifreezing heater in the cooling tower water tank in consideration of the outside air temperature. The temperature of the cooling water is kept at 8 to 10 ° C. by the antifreezing heater even in the winter. Even in the hot water multi-system, the anti-freezing heater is used in the case of winter cooling, but if the cooling water inlet temperature is 5 ° C or less at the start of cooling operation, it is judged that the outdoor unit control is abnormal and the cooling operation is performed to protect the outdoor unit. Do not do.

According to the present invention, cooling can be started up quickly,
If the cooling water inlet temperature is 5 ° C or higher, cooling operation can be performed even in winter.

[0022]

According to the present invention, since the control means for performing the forced heating operation according to the cooling water inlet temperature at the start of the cooling operation is provided, the cooling rising can be accelerated and the cooling water inlet temperature is 5 ° C. or more. This has the effect of enabling air-conditioning operation even in winter.

[Brief description of drawings]

FIG. 1 is a diagram showing an operation of a control means according to an embodiment of the present invention.

FIG. 2 is a diagram showing control steps in FIG.

FIG. 3 is a system diagram showing a conventional technique.

[Explanation of symbols]

1 regenerator 2 separator 3 low temperature regenerator 2 condenser 3 absorber 4 evaporator 5 heat exchanger 7 Solution circulation pump 8 Solution bypass valve 10 Cooling / heating switching valve 12 Cooling water pump 21 Cooling Tawa 52,53 Indoor unit 59 control box

Continuation of front page (56) Reference JP-A-9-89410 (JP, A) JP-A-6-257882 (JP, A) JP-A-5-332640 (JP, A) JP-A-8-247571 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 15/00 306 F25B 15/00

Claims (2)

(57) [Claims] 1. A dilute solution fed from an absorber is heated by a regenerator to separate into a refrigerant vapor and a concentrated solution, and the concentrated solution is circulated to the absorber through a cooling / heating switching valve and / or a solution bypass valve. An absorption type chiller / heater that circulates the refrigerant vapor to a condenser and an evaporator, a cooling circuit that circulates cooling water to the condenser through the absorber by a cooling water pump, and controls at least the cooling / heating switching valve. In the absorption type cold heat generating device comprising a control means for controlling and a refrigerant circuit for circulating a phase change refrigerant between the evaporator and at least one indoor unit, the control means is a cooling water inlet at the start of cooling operation. An absorption-type cold heat generator characterized in that, when the temperature is low, the operating time is controlled to be long according to the low temperature and forced heating is performed. 2. The control means has an inlet temperature of cooling water of 8 ° C.
At 15 ° C, the cooling / heating switching valve is opened for 10 minutes, the solution bypass valve is opened, the cooling water pump is delayed for 5 minutes to perform forced heating for 10 minutes, and the inlet temperature of the cooling water is 5 ° C. When the temperature is 8 ° C, the cooling / heating switching valve is opened for 15 minutes, the solution bypass valve is opened, and the cooling water pump is turned on.
The absorption type cold heat generator according to claim 1, wherein the cooling water inlet temperature is raised to 15 ° C or higher by performing a delayed heating after 15 minutes to perform forced heating for 15 minutes.