JP5606796B2 - Absorption-type device and method for adjusting cooling capacity of absorption-type device - Google Patents

Description

  The present invention relates to an absorption type apparatus capable of energy-saving operation at a predetermined time when cooling is performed by an absorption type refrigerator or an absorption type chiller / heater (hereinafter referred to as an absorption type apparatus).

  When cooling is performed by an absorption type device, the cooling water inlet temperature is set to a predetermined value temperature (for example, 32 ° C.) corresponding to the rating of the absorption type device (for example, brine outlet temperature: 7 ° C.). In the cooling tower provided in the middle of water circulation, the cooling tower fan provided there is rotated to adjust the temperature of the cooling water to be lowered. On the other hand, especially when the ambient temperature is low, such as in the winter, when the user wants to increase the cooling / cooling temperature by the absorption device from the viewpoint of energy saving operation of cooling / cooling, that is, the brine outlet temperature is set high. You may want to An example of a general absorption type device is disclosed in Patent Document 1 below.

JP 2002-156169 A

However, when adjusting the temperature of the cooling water in a conventional absorption device, the inlet temperature of the cooling water becomes lower than a predetermined value due to the influence of the ambient temperature such as the outside air temperature, and the absorption liquid temperature in the absorber is affected by that influence. As a result, the absorption of the refrigerant vapor by the absorbing liquid is excessively promoted, the inside of the evaporator is excessively brought into a high vacuum state, and the evaporation of the refrigerant is excessively promoted. As a result, the cooling effect on the brine is promoted, and there is a problem that the increase of the brine outlet temperature cannot be set according to the user's wish. In addition, the amount of refrigerant liquid that accumulates in the lower part of the evaporator decreases, and in some cases, there is a problem that so-called air biting of the refrigerant pump that circulates the refrigerant liquid occurs.
Therefore, the problem to be solved is to provide an absorption type apparatus capable of energy-saving operation of cooling and cooling when the environmental temperature is low.

In view of the above problems, the first invention is that the brine passes through the evaporator, returns to the evaporator via the heat load device, and the cooling water passes through the absorber by the power of the cooling water pump. A cooling water circulation path that can pass through a cooling tower provided with a cooling tower fan and return to the absorber,
A temperature sensor for measuring a cooling water inlet temperature of the cooling water entering the absorber ;
A cooling capacity adjusting means capable of adjusting and controlling so that the cooling capacity of the cooling water with respect to the absorption liquid of the absorber is lowered;
The cooling capacity adjusting means comprises a flow rate control means for controlling the flow rate of cooling water circulated by the cooling water pump,
The flow rate control means gives an inverter circuit capable of adjusting and controlling the number of revolutions of the cooling water pump, a brine set temperature equal to or higher than a brine rated temperature at the evaporator outlet, and a cooling water inlet temperature measured by the temperature sensor. And a memory capable of reading a formula or a data table for obtaining a limiting rate for the rated flow rate of the cooling water pump for achieving the brine set temperature until the brine set temperature is changed, or Provided is an absorptive device characterized in that an operation that satisfies the brine set temperature requirement is continued until a stop command for the absorptive device is received .

According to a second aspect of the present invention, a brine circulation path in which brine passes through an evaporator and returns to the evaporator via a heat load device, and cooling water is provided with a cooling tower fan through an absorber by power of a cooling water pump. A cooling water circuit that can pass through the cooling tower and return to the absorber,
Providing a temperature sensor for measuring the cooling water inlet temperature of the cooling water entering the absorber ;
To achieve the one brine set temperature based on one of the brine set temperatures set sequentially higher than the brine rated temperature of the evaporator outlet and the cooling water inlet temperature measured by the temperature sensor A limiting rate for the rated flow rate of the cooling water pump is obtained, the cooling water pump is operated at a rated speed based on the limiting rate, and a stop command for the absorption type device is issued until there is a request to change the brine set temperature. Until it receives the one brine set temperature requirement.
This is a method for adjusting the cooling capacity of the absorption type device.

In the first invention and the second invention , since the cooling capacity adjusting means capable of adjusting and controlling the cooling capacity of the cooling water with respect to the absorbing liquid is provided, the cooling capacity of the cooling liquid can be decreased. The outlet temperature is raised above the rated value, and the set brine outlet temperature can be achieved. Therefore, energy saving operation of cooling and cooling is possible, and the amount of refrigerant evaporation is reduced, and the occurrence of air biting is easily prevented.
Also, if the brine set temperature and the cooling water inlet temperature are given, the limiting rate of the cooling water pump can be obtained, so the flow rate of the cooling water pump can be reduced, thereby reducing the cooling capacity of the cooling water and raising the brine outlet temperature And set brine outlet temperature can be achieved.

It is a whole system diagram of an absorption type device concerning the present invention which also displayed heat load equipment. It is explanatory drawing of the control apparatus of FIG. It is a graph used for one control method concerning the present invention. It is a graph used for the other control method which concerns on this invention. It is a graph used for the other control method which concerns on this invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The present invention may be a single-effect absorption device or a double-effect or higher-effect absorption device, but the entire structure will be described with reference to FIG. 1, taking a typical double-effect absorption chiller / heater as an example. To do. It is connected to a heat load device F such as an external indoor air conditioner, thereby enabling cooling and heating.
In the case of cooling, the on-off valves V1, V2, and V3 are closed. The casing is divided into an upper body 11 and a lower body 10. An evaporator 12 is formed on one side of the lower body 10 in the left-right direction, and an absorber 14 is formed on the other side. The upper body 11 is provided with a low temperature regenerator 18 and a condenser 20. On the other hand, a high temperature regenerator 16 is also provided. The high temperature regenerator 16 in this example is a burner type. In the following, the role of each of these devices and the flow of refrigerant and absorbent are outlined.

  The evaporator 12 is disposed so that a brine pipe D through which brine (water here) circulates through the heat load device F flows. The absorber 14 normally passes through a cooling water pipe C1 through which cooling water circulated through the cooling tower RT flows, and the cooling water pipe C1 exiting the absorber 14 also passes through the condenser 20 and exits the condenser 20. The cooling water pipe C1 is connected to the cooling tower RT so that the cooling water can be circulated.

  The refrigerant vapor (water in this example) evaporated by the evaporator 12 is absorbed by the absorber 14 in the absorbing liquid (lithium bromide solution in this example), and the high vacuum state of the evaporator is maintained. The absorbent that has absorbed the refrigerant has a reduced concentration and becomes a diluted absorbent. The dilute absorbent stored in the lower part of the lower body 10 and in the lower part of the absorber 14 is flowed to the dilute absorbent pipe H1 by the absorbent pump P1 and travels to the high temperature regenerator 16. In the middle of this, heat is removed from the concentrated absorbent via the low-temperature heat exchanger N1 with the concentrated absorbent pipe H3 through which the concentrated absorbent flows, which will be described later, and the temperature rises. Thereafter, the dilute absorbing liquid also takes heat from the intermediate absorbing liquid via the high temperature heat exchanger N2 between the intermediate absorbing liquid pipe H2 through which the intermediate absorbing liquid whose concentration has become intermediate by the high temperature regenerator 16 flows. The temperature rises.

  In this way, the diluted absorbent whose temperature is higher than that when it comes out of the absorber 14 flows into the high temperature regenerator 16. Then, it is heated by the burner 17. When the diluted absorbent is heated by the burner 17 in the high-temperature regenerator 16, the refrigerant is evaporated and separated. This refrigerant vapor passes through the low-temperature regenerator 18 described above through the refrigerant pipe R1. On the other hand, the intermediate absorption liquid whose intermediate concentration is obtained by evaporating and separating the refrigerant in the high temperature regenerator 16 flows through the intermediate absorption liquid pipe H2 and enters the low temperature regenerator 18.

  The intermediate absorption liquid that has entered the low-temperature regenerator 18 is heated by the heat transfer section of the above-described refrigerant pipe R1 in which the refrigerant vapor flows. Due to this heat, the refrigerant vapor further evaporated from the intermediate absorption liquid enters the condenser 20. Further, the refrigerant vapor flowing through the refrigerant pipe R1 enters the condenser 20 via the refrigerant pipe tip portion R1 'as vapor or as a refrigerant liquid. The refrigerant vapor in the condenser 20 is cooled by the cooling water flowing through the heat transfer section of the cooling water pipe C1 passing through the inside of the condenser 20 and returns to the refrigerant liquid.

  This refrigerant liquid flows down to the evaporator 12 through the second refrigerant pipe R2. The refrigerant liquid collected in the lower part of the evaporator 12 is sprayed from the sprayer R3A provided in the upper part of the evaporator 12 through the third refrigerant pipe R3 by the refrigerant pump P2. The sprayed refrigerant liquid takes evaporative heat from the brine flowing through the heat transfer section of the brine pipe D to become refrigerant vapor, and lowers the temperature of the brine. As described above, the refrigerant vapor is absorbed by the absorbent in the absorber 14.

  The above is an explanation of the case where the heat load device F is cooling, but in the case of heating, the on-off valves V1, V2, V3 are opened, the cooling water pump P3 is stopped, and cooling water is supplied to the cooling water pipe C1. The gas burner 17 is ignited without flowing, and the high temperature regenerator 16 heats the diluted absorbent. The refrigerant vapor generated by this heating enters the absorber 14 and the evaporator 12 from the middle of the refrigerant pipe R1 mainly through the heating pipe R1 "having a small flow resistance. Thus, through the heat transfer section of the brine pipe D. The brine is heated and the heat load device F can be heated.

  On the other hand, the refrigerant vapor heats the brine in the evaporator 12, loses heat and condenses into a refrigerant liquid. This refrigerant liquid enters the lower part of the absorber 14 through the fourth refrigerant pipe R4, and is mixed with the absorption liquid flowing in through the absorption liquid pipe H2 'by evaporating and separating the refrigerant in the high temperature regenerator 16. And it is sent to the high temperature regenerator 16 by the operation of the absorption liquid pump P1.

  The structure of the above-described cooling water pipe C1 that circulates the cooling water, which is a part of the present invention, will be described in detail. After the cooling water exits the condenser 20, the cooling water pipe C1 branches before reaching the cooling tower RT, and is divided into a main pipe C1A and a bypass pipe C1B on the cooling tower inflow side connected to the cooling tower RT. The bypass pipe C1B is connected to the main pipe C1A on the side where the cooling water flows out from the cooling tower RT. The cooling water pump P3 is positioned downstream of the communication connection position.

  A three-way valve B3 as an electric control valve is disposed at the branch position. A two-way valve B2 is provided downstream of the three-way valve and in the middle of the main pipe C1A on the cooling tower inflow side. It is arranged. The three-way valve, the two-way valve, the inverter part P3I of the cooling water pump P3, and the inverter part RFI of the cooling tower fan RF provided in the cooling tower RT are electrically connected to the control device 30, respectively. ing.

  In addition, a temperature sensor S1 is provided in the cooling water pipe C1 in the vicinity of the inlet through which the cooling water flows into the absorber 14, and the output of the temperature sensor S1 is connected to be input to the control device 30. As shown in FIG. 2, the control device 30 includes a central processing unit (CPU) 32, a memory 34 such as a ROM, and an input / output unit (I / O) 36. The graph of FIG. Calculation formulas corresponding to data or graphs are stored in a memory 34 such as a ROM.

  The input / output unit 36 receives the brine rated temperature, the brine set temperature, and the cooling water inlet temperature measured by the temperature sensor S1. The brine rated temperature may be stored in the memory 34 in advance. In response to these input values, in one of the control methods described below, a command is given to the inverter P3I of the cooling water pump P3 in order to control the rotational speed of the cooling water pump P3. In another control method, in order to control the rotation speed of the cooling water fan RF, a command is given to the inverter unit RFI of the cooling tower fan RF, and the opening / closing and opening of the three-way valve B3 and the two-way valve B2 are controlled. Is given.

  One control method uses graph diagram data corresponding to FIG. 3 stored in the memory 34. Further, in the cooling water circulation path, the three-way valve B3 is also connected to the two-way valve B2 so that the cooling water flowing through the cooling water pipe C1 flows through the main pipe C1A and flows into the cooling tower RT without flowing through the bypass pipe C1B. Even open the valve in that direction. That is, in the three-way valve, only the valve through which the cooling water flows into the bypass pipe C1B is closed.

  In FIG. 3, the horizontal axis represents the cooling water inlet temperature measured by the temperature sensor S1, and the vertical axis represents the percentage that is a ratio that limits the rotation of the cooling water pump P3 with respect to the rated rotation. is there. Graph lines G1 to G6 are graph lines with respect to the brine set temperature that is sequentially increased by +0, 1, 2, 3, 4, 5 ° C. with respect to the brine rated temperature. In the case of the brine set temperature between these graph lines, it can be calculated by performing, for example, linear interpolation between adjacent graph lines.

  When a request for a brine set temperature of, for example, + 4 ° C. is input to the brine rated temperature stored in the memory 34 of the control device 30 or input from the outside, the graph line G5 becomes the required line. . Here, assuming that the cooling water inlet temperature measured by the temperature sensor S1 is 25 ° C., the limiting rate of 65% is obtained by the graph line G5. This value is output to the inverter part P3I of the cooling water pump P3. Thereby, the cooling water pump is operated at a rotation speed of 35% of the rated value.

  Thereafter, when the temperature of the cooling water is measured again every predetermined time interval, for example, after 1 minute, it is assumed that the temperature has increased to, for example, 25.5 ° C., unlike the temperature of 25 degrees. In this case, a limiting rate of 58% is obtained by the graph line G5. This value is output to the inverter part P3I of the cooling water pump P3. Thereby, until the next 1 minute, the cooling water pump is operated at a rotational speed of 41% of the rated value.

  Thereafter, similarly, the measured value of the cooling water temperature is read again one minute later, and similarly the rotation of the cooling water pump P3 is controlled. In this way, the operation that satisfies the request for the brine set temperature is continued until the next request for changing the brine set temperature is received or until the stop command for the absorption type device is received.

  In FIG. 4, the horizontal axis represents the cooling water inlet temperature, and the vertical axis represents the ratio of the cooling water flowing to the bypass pipe C1B using the two-way valve B2 and / or the three-way valve B3 shown in FIG. FIG. For example, when a request for a brine set temperature of + 4 ° C. is input, the graph line H5 becomes the request line. Here, if the cooling water inlet temperature measured by the temperature sensor S1 is 25 ° C., a bypass ratio of 46% is obtained by the graph line H5. This ratio signal or this is changed to a valve opening signal and sent to a three-way valve or a two-way valve.

  Since the cooling water starts flowing at a bypass rate of 46% from what was 0%, the cooling water inlet temperature rises. For example, if it becomes 25.5 degreeC after 1 minute, in order to maintain the state located on the graph line H5, it will flow by a 37% bypass ratio this time. Thereafter, similarly, the measured cooling water inlet temperature is read again after 1 minute, and the bypass ratio is similarly controlled. In this way, the operation that satisfies the request for the brine set temperature is continued until the next request for changing the brine set temperature is received or until the stop command for the absorption type device is received.

  FIG. 5 is a graph showing the cooling water inlet temperature on the horizontal axis and the rotation speed ratio of the cooling tower fan RF shown in FIG. 1 on the vertical axis. For example, when a request for a brine set temperature of + 4 ° C. is input, the graph line I5 becomes the request line. Here, if the cooling water inlet temperature measured by the temperature sensor S1 is 25 ° C., a rotation rate ratio of 63% is obtained by the graph line H5. This signal is transmitted to the inverter unit RFI.

  Thus, since the rotation speed ratio of 100% is reduced to the rotation speed ratio of 63% and the rotation starts, the cooling water inlet temperature rises. For example, if it becomes 25.5 degreeC after 1 minute, in order to maintain the state located on the graph line I5, this will be 73% of rotation speed ratio this time. Thereafter, similarly, the measured cooling water inlet temperature is read again after 1 minute, and the rotation speed ratio is similarly controlled. In this way, the operation that satisfies the request for the brine set temperature is continued until the next request for changing the brine set temperature is received or until the stop command for the absorption type device is received.

  INDUSTRIAL APPLICABILITY The present invention can be used for an absorption type apparatus that adjusts and controls the cooling capacity of cooling water.

DESCRIPTION OF SYMBOLS 12 Evaporator 14 Absorber 16 High temperature regenerator 18 Low temperature regenerator 20 Condenser C1 Cooling water pipe C1B Bypass pipe P3 Cooling water pump P3I Inverter part RF cooling tower fan RFI inverter part RT Cooling tower S1 Temperature sensor

Claims (2)

The brine passes through the evaporator, returns to the evaporator via the heat load device, and the cooling water passes through the absorber and the cooling tower provided with the cooling tower fan by the power of the cooling water pump. A cooling water circuit that can be returned to the absorber,
A temperature sensor for measuring a cooling water inlet temperature of the cooling water entering the absorber ;
A cooling capacity adjusting means capable of adjusting and controlling so that the cooling capacity of the cooling water with respect to the absorption liquid of the absorber is lowered;
The cooling capacity adjusting means comprises a flow rate control means for controlling the flow rate of cooling water circulated by the cooling water pump,
The flow rate control means gives an inverter circuit capable of adjusting and controlling the number of revolutions of the cooling water pump, a brine set temperature equal to or higher than a brine rated temperature at the evaporator outlet, and a cooling water inlet temperature measured by the temperature sensor. And a memory capable of reading a formula or a data table for obtaining a limiting rate for the rated flow rate of the cooling water pump for achieving the brine set temperature until the brine set temperature is changed, or The absorption-type apparatus is characterized in that the operation that satisfies the demand for the brine set temperature is continued until the absorption-type apparatus stop command is received . The brine passes through the evaporator, returns to the evaporator via the heat load device, and the cooling water passes through the absorber and the cooling tower provided with the cooling tower fan by the power of the cooling water pump. A cooling water circuit that can be returned to the absorber,
Providing a temperature sensor for measuring the cooling water inlet temperature of the cooling water entering the absorber ;
To achieve the one brine set temperature based on one of the brine set temperatures set sequentially higher than the brine rated temperature of the evaporator outlet and the cooling water inlet temperature measured by the temperature sensor A limiting rate for the rated flow rate of the cooling water pump is obtained, the cooling water pump is operated at a rated speed based on the limiting rate, and a stop command for the absorption type device is issued until there is a request to change the brine set temperature. Until it receives the one brine set temperature requirement.
A method for adjusting the cooling capacity of an absorption type device.

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