JP3084716B2 - Absorption chiller / heater and its operation method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller / heater, and more particularly to an absorption chiller / heater having a mechanism capable of being separated into a cooling cycle and a heating cycle, and an operation method thereof.

[Conventional technology]

2. Description of the Related Art Conventionally, an absorption cooling / heating apparatus for producing hot water simultaneously with cold water is known and described in Japanese Patent Publication No. 61-38387.

According to such an apparatus, when the cooling load is smaller than the heating load, the refrigerant condensed in the hot water heater is supplied to the condenser-
By bringing it to the evaporator side, the cooling capacity can be provided without the need to concentrate the solution especially in the low-temperature generator. in this case,
The cooling capacity can be controlled by adjusting the amount of refrigerant brought to the condenser-evaporator side.

When the cooling capacity is insufficient, the cooling capacity control valve of the refrigerant vapor line may be set to the opening direction to perform the solution concentration and the refrigerant separation by the low-temperature generator.

When the cooling load becomes very low, the solution bypass valve is opened to reduce the absorption capacity and balance the load with the capacity (required value and supply value).

[Problems to be solved by the invention]

By the way, in the absorber, the absorbing solution absorbs the refrigerant vapor from the evaporator. However, the solution cannot absorb the refrigerant vapor unless cooled by cooling water to lower the temperature. As the cooling load becomes smaller, the proportion of the amount of heat when cooling the solution returning from the generator via the solution heat exchanger becomes larger than the heat of absorption when absorbing the refrigerant.

However, the heat for cooling the solution returning from the generator via the solution heat exchanger to a temperature at which the refrigerant can be absorbed is:
It is simply thrown away in cooling water, which is ineffective energy.

Accordingly, an object of the present invention is to provide an absorption chiller / heater that can be effectively used for heating without discarding such ineffective energy into cooling water, and an operation method thereof.

[Means for solving the problem]

In order to achieve the above object, in the present invention, an absorber, an evaporator, a high temperature generator, a low temperature generator, a condenser, a hot water heater,
A high-temperature heat exchanger, a low-temperature exchanger, and these devices are connected by a solution path and a refrigerant path, and the refrigerant path has a refrigeration cycle system and a hot water cycle system. In the water machine, a cooling load detector for detecting a cooling load is provided on a cooling water path, and a cycle separation mechanism for separating the cooling / heating water machine into a cooling cycle and a heating cycle is provided on a solution path and a refrigerant path, and the cooling load detection is performed. A control mechanism for operating a cycle separation mechanism in accordance with a detection signal of the heat generator, wherein the cycle separation mechanism includes a hot water generator in a refrigerant path from a high temperature generator. From the refrigeration cycle path from the branch point of the cycle system to the condenser, and from the branch point where the refrigerant that has passed through the hot water heater in the hot water cycle path branches to the high-temperature generator And hot water cycle system path leading to the condenser,
The control valve may be provided in the dilute solution path and the concentrated solution path connected only to the high temperature generator in the solution path.

In the operation method of the absorption chiller / heater, when the cooling load detector detects a predetermined load or less, a cycle separation mechanism is operated to separate the cycle into a cooling cycle and a heating cycle. Activate to combine the cycles.

Further, the present invention provides the absorption chiller / heater, wherein a concentration detector for detecting the concentration of the concentrated solution is provided in the concentrated solution path from the high temperature generator, and a detection signal of the cooling load detector and a concentration detector are provided. A control mechanism for operating the cycle separation mechanism in response to a detection signal of the concentration of the concentrated solution is provided.

Then, in the method of operating the absorption chiller / heater, the cooling load detector detects a predetermined load or less, and if the concentration of the concentrated solution is less than a predetermined value, the solution is concentrated to a predetermined value,
If the concentration of the concentrated solution is equal to or higher than a predetermined value, the cycle separation mechanism is operated to separate the cooling cycle and the heating cycle, and the cooling load detector detects a predetermined load or less, If the concentration of the concentrated solution is lower than the predetermined value, the solution is concentrated to the predetermined value.If the concentration of the concentrated solution is higher than the predetermined value and lower than the crystal judgment set value, the concentration of the concentrated solution is higher than the predetermined value and the crystal judgment concentration is higher than the predetermined value. Then, after increasing the amount of circulating solution, the cycle separation device is operated to separate into a cooling cycle and a heating cycle.

Next, the heating cycle / cooling cycle separation mechanism will be described in detail.

First, the cycle separation mechanism will be described. The cycle separation mechanism is provided for separating the absorption chiller / heater into the heating cycle and the cooling cycle, and is specifically performed by control valves provided in the solution path and the refrigerant path. This control valve is
In the solution path, from the branch point to the low-temperature generator in the dilute solution path connected to the high-temperature generator to the high-temperature generator, and from the high-temperature generator in the concentrated solution path to the junction with the concentrated solution from the low-temperature generator. In the refrigerant path, between the branch point from the high-temperature generator to the hot water heater of the refrigerant path to the condenser, and from the branch point where the refrigerant that has passed through the hot water heater branches to the high-temperature generator. It is provided between the condenser.

Then, by closing all the control valves, the heating cycle and the cooling cycle are separated. The heating cycle is a combination of a high-temperature generator and a hot water heater, in which the solution of the high-temperature generator is heated, the refrigerant vapor generated from the solution is condensed by the hot water heater, the hot water is heated, and this hot water is supplied to the heating load. Used.

Also, the separated cooling cycle consists of an absorber, an evaporator,
This is a combination of a high temperature generator and a condenser. The absorber and the evaporator generate cooling capacity by the concentration energy of the solution, and are used for cooling load.

The separation of the heating cycle and the cooling cycle by operating such a cycle separation mechanism is performed when the cooling load detector detects a predetermined load or less, that is, when the cooling load is less than a certain level (for example, 10% of the rated value). When the heating load is high, the cooling cycle and the heating cycle are separately operated. If the cooling load is more than a certain level (for example, 10% of the rating), it is not necessary to separate the cooling cycle from the heating cycle. Even when there is no heating load, the heat source supplied to the high temperature generator may be adjusted. So there is no need for separation.

However, if the operation is continued while being separated, the concentration energy of the cooling cycle is lost, so that the cooling capacity is reduced and the temperature of the chilled water is increased. Therefore, taking this rise into account, both cycles for concentrating the solution are integrated. Then, when the temperature of the chilled water decreases (the cooling load decreases), the chilled water separates again. In order to avoid such frequent switching with the separation, it is possible to use a concentration detector to concentrate the solution to a certain degree or more during the separation.

[Action]

In the present invention, in the absorption chiller / heater, after the cooling load is reduced, a heating cycle mainly comprising a high-temperature generator and a hot water heater and a cooling cycle mainly comprising an evaporator and an absorber are separated. The heat of the high-temperature generator side is prevented from coming to the absorber side, and the cooling load is mainly the concentration energy (heat storage energy) of the solution on the absorber side, that is, the evaporator and the absorber. It is provided by a cooling cycle and eliminates ineffective energy, in which heat coming from the high-temperature generator is discarded into cooling water by an absorber after the conventional cooling load is reduced.

In addition, the cooling cycle at the time of separation, since the cooling load can be covered only by the concentration energy of the solution, the concentration of the concentrated solution at the time of separation is maintained at a predetermined value or more by a concentration detector, and If the concentration is too high, there is a risk that crystals will form in the concentrated solution path. In such a case, the solution circulation amount is increased to avoid a local high concentration.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these embodiments.

Embodiment 1 FIG. 1 is a schematic process diagram showing an absorption cooling / heating water apparatus of the present invention. In FIG. 1, an absorber A, an evaporator E, a high temperature generator GH, a low temperature generator GL, a condenser C, a hot water heater W, a high temperature heat exchanger XH, and a low temperature heat exchanger XL are provided. As the solution path, the solution pump PS, lines 1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 1
Some of the above devices are connected by 0 and 11 to form a solution circulation path. The refrigerant path includes a refrigeration cycle system refrigerant path and a hot water cycle system refrigerant path. The refrigeration cycle system refrigerant path includes pipes 12 and 13, valve 43, heater 1
4. The low-temperature generator system refrigerant path from the pipe 15 to the condenser C via the pipes 17 and 16 to the evaporator E, and the solution in the low-temperature generator GL evaporates and is condensed in the condenser C. A condenser-system refrigerant path to the evaporator E via the pipes 17 and 16; a refrigerant pump PM for recirculating the refrigerant to the evaporator E repeatedly;
8 and 19 are provided.

The hot water cycle system refrigerant path includes a pipe 21, a hot water cycle branch point 20, a pipe 21, a heating side 22 of the hot water heater W, and a pipe.
23, via the control valve 24, through the branch point 36, through the pipes 44, 25 to the condenser C, and through the pipes 17, 16 to the evaporator E.
Then, the refrigerant path branched at the branch point 36 passes through the pipe 37,
Circulated to high temperature generator GH. 26 and 27 are cooling water pipes, 28 is a cold water pipe, 29 is a heating pipe, and 30 is a heat source calorie control valve. Reference numeral 31 denotes a temperature detector for detecting a chilled water load.

In the apparatus configured as described above, the refrigerant load detector 31 detects that the refrigeration load has decreased (usually, it is detected by a decrease in the chilled water temperature, or the return temperature from the cooling load side and the supply temperature). And a cycle separation mechanism S that separates the chiller / heater into a cooling cycle and a heating cycle is operated to separate the chiller / heater. The separation mechanism shown in FIG. 1 includes valves 39 and 43 (also serving as a cooling capacity adjusting valve) in the refrigerant vapor line connecting the high temperature generator GH and the low temperature generator GL, and the high temperature generator GH.
And a solution outlet valve 52 from the high-temperature generator GH. When separating, valves 39, 43,
Close all 51 and 52.

Heating after separation is obtained by condensing refrigerant vapor generated in the high-temperature generator GH in the hot water heater W. Condensate is valve 23 (fully open)
And returns to the high-temperature generator GH via the pipe 37 and circulates.

The cooling after the separation is obtained by absorbing the refrigerant from the evaporator E using the concentration of the solution circulating in the absorber A, the low-temperature heat exchanger XL, and the low-temperature generator GL. That is, by the solution pump PS,
The solution in the absorber A is connected to lines 2 and 8, the low-temperature heat exchanger XL, and the line 9
Through the low temperature generator GL. The cryogenic generator GL simply passes through the solution, which is sprayed into absorber A via line 10, cryogenic heat exchanger XL, lines 11,7.
Cooling capacity control involves adjusting the amount of solution spray (lines 34 and 35, valve 5
Adjustment of the bypass amount of the bypass path consisting of 0)
In FIG. 1, a solution bypass valve 50 is used to balance the load and the capacity. When the valve is opened, the solution spray amount is reduced, and the absorption capacity is reduced.

At the time of cycle separation, when the solution concentration is low, separation can be performed after increasing the concentration energy. That is, by bringing the refrigerant condensed in the hot water heater W to the condenser C-evaporator E side, the solution concentration increases, and it can be used in the cooling cycle after separation.

At the time of cycle separation, the concentration detector 32 outputs the high-temperature generator GH,
The solution concentration on the high-temperature heat exchanger XH concentrated solution side may be high, and if the solution is separated as it is, there is a possibility of crystallization in the high-temperature heat exchanger XH concentrated solution line from the high-temperature generator GH outlet. (When the flow stops and the temperature drops). In this case, since the cooling load is small, the concentration of the dilute solution should be low.If the circulation amount is increased and the temperature range between the dilute solution and the concentrated solution is reduced, the concentration of the concentrated solution is reduced and the danger of crystallization is eliminated. . That is, the circulation is increased, the concentration range between the dilute solution and the concentrated solution is reduced and then separated, and as an example of a mechanism for increasing the circulation amount, there is pressure control of a high-temperature generator, and by increasing the pressure, Therefore, the outflow from the high-temperature generator GH increases, and the inflow increases accordingly (the circulation amount increases). When the heating capacity control valve 24 at the lower part of the hot water heater is closed, the pressure temporarily decreases, but the pressure rises and returns to the original amount.
Pressure can be controlled.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, since it can isolate | separate into a cooling cycle part and a heating cycle part, when the cooling load becomes small, the amount of heat discharged | released to the cooling water in an absorber can be used effectively for heating.

[Brief description of the drawings]

FIG. 1 is a schematic process diagram showing an absorption cooling / heating water apparatus of the present invention. A: Absorber, E: Evaporator, GH: High temperature generator, GL: Low temperature generator, C: Condenser, W: Hot water heater, XH: High temperature heat exchanger, XL: Low temperature heat exchanger, PS …… Solution pump, PM …… Refrigerant pump, S …… Cycle separation mechanism, 1-13, 15-19, 21, 23, 25, 34, 35, 37, 44 …… Pipe line, 14 ... heating pipe, 20, 36 ... branch point, 22 ... heating side, 24, 39, 43, 50-52 ... control valve, 26, 27 ... cooling water pipe, 28 ... cold water pipe, 29 ... … Heating tube, 30… heat source calorie control valve, 31… cooling load detector, 32… concentration detector,

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-15655 (JP, A) JP-A-54-149960 (JP, A) JP-A-58-43366 (JP, A) 65956 (JP, A) JP-A-56-142364 (JP, A) JP-B-61-38387 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00, 29 / 00

Claims (6)

(57) [Claims] 1. An absorber, an evaporator, a high temperature generator, a low temperature generator, a condenser, a hot water heater, a high temperature heat exchanger, a low temperature heat exchanger, and these devices are connected by a solution path and a refrigerant path,
The refrigerant path has a refrigeration cycle system and a hot water cycle system.In an absorption chiller / heater capable of simultaneously taking out cold water and hot water, a cooling load detector for detecting a cooling load is provided in the cold water path, and a solution path and a refrigerant are provided. A cycle separating mechanism for separating the cooling / heating machine into a cooling cycle and a heating cycle on a path, and a control mechanism for operating the cycle separating mechanism based on a detection signal of the cooling load detector is provided. Cold and hot water equipment. 2. A cycle separation mechanism comprising: a refrigeration cycle system path from a high temperature generator to a condenser from a branch point of a refrigerant path to a hot water cycle system; and a refrigerant passing through a hot water heater in the hot water cycle system path. A control valve provided in a hot water cycle system path from a branch point branching to the generator to the condenser, and a dilute solution path and a concentrated solution path connected only to the high temperature generator of the solution path. 2. The absorption cooling / heating water device according to 1. 3. A concentration detector for detecting the concentration of the concentrated solution is provided in the concentrated solution path from the high-temperature generator, and a detection signal of the cooling load detector and a detection signal of the concentration of the concentrated solution by the concentration detector are provided. 3. The absorption chiller / heater according to claim 1, further comprising a control mechanism for operating the cycle separation mechanism. 4. The method for operating an absorption chiller / heater according to claim 1, wherein when the cooling load detector detects a predetermined load or less, a cycle separation mechanism is operated to separate the cooling cycle and the heating cycle. And operating the cycle separation mechanism to unite the cycles when the increase in load is detected. 5. The method according to claim 3, wherein said cooling load detector detects a load below a predetermined load, and if the concentration of the concentrated solution is less than a predetermined value, the solution is reduced to a predetermined value. A method for operating an absorption chiller / heater, comprising: concentrating and, if the concentration of a concentrated solution is equal to or higher than a predetermined value, operating a cycle separation mechanism to separate into a cooling cycle and a heating cycle. 6. The method for operating an absorption chiller / heater according to claim 3, wherein the cooling load detector detects a load of not more than a predetermined value, and if the concentration of the concentrated solution is less than a predetermined value, the solution is reduced to a predetermined value. Concentrate, if the concentrated solution concentration is equal to or more than a predetermined value and less than the crystal judgment set value, and if the concentrated solution concentration is equal to or more than the predetermined value and the crystal judgment set value or more, increase the solution circulation amount,
A method for operating an absorption chiller / heater, wherein a cycle separator is operated to separate a cooling cycle and a heating cycle.