JP2003307363A - Refrigerating equipment combined with absorption type and compression type and its driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide refrigerating equipment combined with an absorption type and a compression type and efficiently driving by adjusting the driving state of a compression refrigerating machine according to the state of cooling loads and absorption refrigerating effects. <P>SOLUTION: This refrigerating equipment is formed by combining the absorption refrigerating machine having an evaporator E, with a compression refrigerating machine having one or more compressors Mc, a condenser Cc connected to the evaporator E of the absorption refrigerating machine in a heat exchange relation or a second condenser Ccx cooling using outside air or cooling water along with the condenser Cc, and an evaporator Ec exhibiting a refrigerating effect. The compression refrigerating machine is provided with a control valve feeding refrigerant liquid to the evaporator Ec, a sensor detecting a superheat degree of refrigerating steam of the outlet of the evaporator Ec, a means setting the target value of the superheat degree, and a control means controlling the capacity of the evaporator Ec by changing the target value of the superheat degree of the refrigerant steam of the outlet of the evaporator Ec. The plurality of compression refrigerating machines can be connected to the single absorption refrigerating machine. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus that can be used in an air conditioner, and more particularly, to an absorption refrigerating machine or an absorption cold / hot water machine that uses exhaust heat from an engine, a turbine, various plants, etc. as a heat source. The present invention relates to a refrigerating apparatus that effectively uses the refrigerating effect of 1. in combination with a compression refrigerator and an operating method thereof.

[0002]

2. Description of the Related Art In a cogeneration system, hot water having a relatively low temperature is supplied together with electricity. This hot water is not so high in temperature, is classified into low potential energy, and is often used for hot water supply or heating. Recently, it has also been often used for cooling as a heat source of an absorption refrigerator. . In a cogeneration system, this hot water is obtained by cooling the engine (jacket hot water), recovering heat from the engine exhaust gas, or recovering heat from the exhaust gas of the gas turbine. The exhaust gas may be directly used as a heat source for the absorption refrigerator without being converted into hot water. In some cases, the absorption refrigerator is operated with low potential energy alone, but as a combined air conditioner, a method of using it together with high potential energy to reduce the required amount of high potential energy has also been proposed and adopted.

When operating the absorption chiller-heater with low potential energy alone, it is difficult to extract the load capacity corresponding to the cooling and heating load because the amount of exhaust heat supplied is small or unstable. In order to solve this, there is known a refrigerating apparatus that cools a circulating refrigerant by using cold heat of an absorption refrigerator as a heat radiation source of a compression refrigerator. (JP-A-11
No. 223412). However, in this refrigeration system, the heat source side heat exchanger of the compression refrigerator is provided with cooling by air and cooling by the absorption refrigerator in series, and unless the compressor of the compression refrigerator is operated, refrigeration of the absorption refrigerator is performed. The effect could not be used. In addition, since the refrigerant liquid is only cooled, even if the heat source heat quantity of the absorption chiller (hot water heat quantity, etc.) increases, it is not possible to increase the amount of the absorption refrigeration effect that can be used, and the exhaust heat supply and The response to the increase or decrease in the cooling load was insufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and can adjust the operating state of the compression refrigerator according to the cooling load and the state of the absorption refrigeration effect, which is economical and efficient. An object of the present invention is to provide a refrigerating apparatus that can be used for an air conditioner that can be operated and an operating method thereof.

[0005]

In order to solve the above problems, in the present invention, an absorption refrigerator having an evaporator E, one or more compressors, and a heat exchange relationship with the evaporator E of the absorption refrigerator. A condenser Cc connected to, or a refrigerating apparatus in which the condenser Cc is combined with a compression refrigerator having a second condenser Ccx cooled with outside air or cooling water and an evaporator Ec exhibiting a refrigerating effect, The compression refrigerator comprises a control valve for supplying a refrigerant liquid to the evaporator Ec, a sensor for detecting the superheat degree of the outlet refrigerant vapor of the evaporator Ec, and means for setting a target value of the superheat degree. A refrigerating apparatus combining an absorption type and a compression type, which has a control means for controlling the capacity of the evaporator Ec by changing a target value of the superheat degree of the outlet refrigerant vapor of the evaporator Ec. . In the refrigeration system, a plurality of compression refrigerators can be connected to one absorption refrigerator. Further, in the present invention, in the operating method of the refrigerating apparatus, the control means for controlling the capacity of the evaporator Ec performs an operation in which all the compressors are stopped and the refrigerant vapor from the evaporator Ec is condensed by the condenser Cc. You can work when you are.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention makes it possible to obtain the refrigerating capacity of a compression refrigerating machine by the absorption refrigerating effect alone without operating the compressor of the compression refrigerating machine, and even when the compressor is in operation. In addition, the absorption refrigeration effect can be sufficiently exerted, and the absorption refrigeration effect can be preferentially used. Next, the present invention will be described in detail with reference to the drawings. 1 to 4 are flow configuration diagrams showing an example of connection of component devices on the compression refrigerator side of the refrigerating apparatus of the present invention. In the figure, Mc is a compressor, Ec
Is an evaporator, Cc is a condenser, Ccx is a second condenser, Ta,
TR and Ts are temperature sensors, and Sc is a supercooler.

In FIG. 1, (a) is an overall configuration diagram,
(B) is a detailed view of the Ec portion, in which the refrigerant vapor from the evaporator Ec is sucked into the condenser Cc while the compressor Mc is stopped, and is condensed with the compressor Mc or the compressor Mc during operation of the compressor Mc. It is sucked into the container Cc. If the temperature of the heat transfer medium from the absorption type is low and the refrigerant vapor can be condensed in the condenser Cc, it is sucked into the condenser Cc and condensed in the condenser Cc. If the temperature of the heat transfer medium from the absorption type is high and the refrigerant vapor cannot be condensed in the condenser Cc, it exists in the condenser Cc in the form of refrigerant vapor,
Almost no heat transfer occurs. In the figure, the subcooler Sc may be omitted.

FIG. 1B shows an example of the evaporator Ec.
An indoor unit (air cooler) is shown. As shown in FIG. 1B, a controller is provided for each indoor unit to measure the temperature and adjust the expansion valve. That is, the target room temperature To is set by the remote controller or directly set by the controller and compared with the room temperature sensor Ta,
The difference temperature ΔT = Ta−To is sent to the controller of the compressor as the required capacity. Further, the temperature sensor TR at the outlet of the evaporator measures the temperature of the refrigerant superheated vapor, and the refrigerant liquid is supplied with the flow rate limited by the capillary, and the saturation temperature is measured by the room temperature sensor Ts.
Then, the degree of superheat ΔTsh = TR−Ts is obtained, and the expansion valve V1 (refrigerant supply valve) is adjusted so that the target degree of superheat is obtained.

FIG. 2A shows a plurality of compressors Mc, here three compressors Mc, and FIG. 2B shows a case where a plurality of compressors Mc are used, one of which is controlled by an inverter. However, other control may be performed by controlling the number of vehicles (start / stop). FIG. 3 shows a configuration having a system of the compressor Mc and the second condenser Ccx, and a system of the compressor Mc2 and the condenser Cc. Figure 3
Then, it is preferable to apply the present invention to the control in the state where the compressor Mc2 of the system of the condenser Cc is stopped. Figure 4
Is provided with a bypass passage in the compressor Mc when the discharge side of the compressor Mc and the condenser Cc are connected in series. When the compressor Mc is stopped, the bypass is bypassed and the refrigerant vapor is directly cooled. You can drive to condense. While the compressor is operating,
It does not matter if the condenser Cc acts as a supercooler.

Next, the control of the refrigerating apparatus of the present invention will be described. First, regarding the control on the compression refrigerator side, in terms of capacity control, the expansion valve V1 of each evaporator Ec is adjusted so that the superheat degree at the outlet of the evaporator Ec becomes a target value, or the refrigerant at the outlet of the evaporator Ec is adjusted. Adjust the steam superheat to a specified value. The required capacity of the evaporator Ec of the compression refrigerator is the difference between the temperature sensor measuring the temperature of the medium cooled by the evaporator Ec and the target temperature of the medium to be cooled. Evaporator Ec
When there are a plurality of units, the total value or weighted average value in which the capacities of the respective evaporators Ec are added is used. In the required capacity, for example,
The compressor Mc is operated at the frequency shown in Table 1. When the temperature difference is decreasing, the frequency is a downward gradient (X side), and when the temperature difference is increasing, it is an upward gradient (Y side) frequency. 0.4 ° C in the same region when the room temperature is downhill and uphill
Since it has a difference of, this acts as a hysteresis, and it is possible to suppress frequent changes in frequency.

[0011]

[Table 1]

The capacity control after the compressor Mc is stopped can be controlled by adjusting the amount of the absorption refrigeration effect transmitted to the compressor side. For example, it is easy to adjust the amount of the medium carrying the absorption refrigeration effect. Method, but requires a flow control valve. The present invention newly makes it possible to control the capacity without using a flow rate control valve for the carrier medium. Specifically, after the compressor is stopped, the superheat target value of the evaporator Ec outlet steam is increased to limit the condensing capacity of the condenser Cc. For example, as shown in Table 2, the target superheat degree is set. ΔT = −0.8 ° C., superheat degree SH = 4.0 ° C., ΔT = −1.6 ° C., superheat degree SH = 8.0 ° C., and ΔT = −0.8 ° C. or less, The degree of superheat is SH = −5 × ΔT.

In this way, the condenser C increases due to the increase in superheat.
The reason why the condensing capacity of c is limited is that the flow rate of the refrigerant flowing through the evaporator is throttled in order to increase the degree of superheat, and as a result, the outlet pressure decreases, and the condensing capacity of the condenser Cc decreases. When operating the compressor, it is desirable to set the superheat target value as small as possible within the range where it can be controlled by following fluctuations, in order to reduce required power and increase efficiency (usually 4 ° C). However, since power is not involved after the compressor is stopped, the outlet pressure of the evaporator Ec can be reduced to set the superheat degree to a large value.

[Table 2]

When one compressor of FIG. 1 is controlled by an inverter, the compressor is operated at a frequency corresponding to the differential temperature as shown in Table 1 during the operation of the compressor. While the compressor is stopped, the method shown in Table 2 is used to adjust the capacity of the condenser Cc for capacity control. In the case of controlling the number of a plurality of compressors in FIG. 2, a method of determining the number of operating machines is used instead of determining the frequency by the temperature difference. If only controlling the number of multiple compressors, the pressure changes stepwise.
As in (b), at least one unit is controlled by an inverter to reduce the pressure change. The inverter frequency is the same as in Table 1. While operating at the maximum inverter speed, one compressor is additionally operated if the differential temperature rises, and if the differential temperature drops while operating at the minimum inverter speed, one compressor is stopped (other than the inverter is preferentially stopped). . After stopping the compressor completely, the capacity of the condenser Cc is adjusted.

When the compressor Mc, the second condenser Ccx, and the condenser Cc of FIG. 4 are connected in series, the compressor is operated at a frequency corresponding to the differential temperature as shown in Table 1 during the operation of the compressor. To do. At this time, the condenser Cc acts as a supercooler. The refrigerant liquid from the second condenser Ccx is cooled. While the compressor is stopped, the method shown in Table 2 is used to adjust the capacity of the condenser Cc for capacity control. The control on the absorption refrigerating machine side is operated so as to make full use of the exhaust heat, and the amount of heat input from the heat source is limited when avoiding freezing of the evaporator refrigerant and avoiding absorption solution crystallization. This control is independent of the compression type,
The control may be performed only on the absorption side.

When the load on the absorption refrigerator is too great or the capacity of the absorption type is too high due to the heat source heat quantity, the evaporation temperature or the refrigeration output temperature of the absorption type becomes too high. Reduce the medium flow rate, etc., or use the condenser C
The heat medium flow rate to c is reduced. These controls may be performed unilaterally from the absorption side. When a plurality of compression refrigerators and one absorption refrigerator are combined, the heat medium circulation amount may be controlled as a whole or individually.

The compression refrigerator uses the available absorption refrigerator output and controls within that range. It should be noted that the control can be performed by associating the compression type side and the absorption type side, but there is a drawback that the control system becomes too complicated. The absorption refrigerator is not particularly limited such as single effect, double effect, and single effect, and is not limited by the working medium of the absorption refrigerator. The form of the heat source is not particularly limited, such as hot water, steam, fuel, or exhaust gas, and is not limited to exhaust heat, and may be an absorption refrigerator that uses an inexpensive fuel as a heat source. Further, each device constituting one compression refrigerator may be a plurality of devices. Although it is described as a compression refrigerator, a mode in which heating operation is performed by a heat pump by switching pipes may be adopted. At that time, heat is applied to the heat pump by using the absorption refrigerator as a cold / hot water machine,
Alternatively, the exhaust heat source may be directly applied to the heat pump.

[0018]

INDUSTRIAL APPLICABILITY According to the present invention, the refrigerating capacity of the refrigerant circuit (refrigerating capacity of the compression refrigerator) can be obtained by the absorption refrigeration effect alone without operating the compressor of the compression refrigerator, and the compressor is operated. It is designed so that the absorption and refrigeration effect can be fully exerted even when it is being used. In addition, the absorption refrigeration effect is preferentially used to enable the operation of the absorption refrigeration effect alone, and the operation state of the compression refrigerator can be adjusted according to the cooling load and the state of the absorption refrigeration effect, which is economical and efficient. The refrigeration apparatus can be used as an air conditioner that can be operated.

[Brief description of drawings]

FIG. 1 is a flow configuration diagram showing an example of a compression refrigerator of a refrigeration apparatus of the present invention, (a) is an overall view, and (b) is a detailed view of an Ec portion.

2A and 2B are flow configuration diagrams showing another example of the compression refrigerator of the refrigeration apparatus of the present invention.

FIG. 3 is a flow configuration diagram showing another example of the compression refrigerator of the refrigeration apparatus of the present invention.

FIG. 4 is a flow configuration diagram showing another example of the compression refrigerator of the refrigerator of the present invention.

[Explanation of symbols]

Mc, Mc1, Mc2: compressor, Ec: evaporator, Cc:
Condenser, Ccx: second condenser, Sc: subcooler, Ta,
TR, Ts: temperature sensor, V1: expansion valve

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor, Koichi Irie             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Tetsuya Endo             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Jun Aoyama             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Tomoyuki Uchimura             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Kodai Fukuzumi             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION

Claims (3)

[Claims] 1. An absorption refrigerator having an evaporator E, one or more compressors, a condenser Cc connected in a heat exchange relationship with the evaporator E of the absorption refrigerator, or the condenser Cc and outside air or A refrigeration apparatus in which a second condenser Ccx cooled with cooling water and a compression refrigerator having an evaporator Ec exhibiting a refrigerating effect are combined, wherein the compression refrigerator supplies a refrigerant liquid to the evaporator Ec. A valve, a sensor for detecting the superheat degree of the outlet refrigerant vapor of the evaporator Ec, and means for setting a target value of the superheat degree are provided, and the target value of the superheat degree of the outlet refrigerant vapor of the evaporator Ec is changed. Therefore, the refrigerating apparatus combined with the absorption type and the compression type is provided with a control means for controlling the capacity of the evaporator Ec. 2. The refrigerating apparatus according to claim 1, wherein a plurality of the compression refrigerators are connected to one absorption refrigerator. 3. The operating method of the refrigerating apparatus according to claim 1, wherein the control means for controlling the capacity of the evaporator Ec stops all the compressors and condenses the refrigerant vapor from the evaporator Ec in the condenser Cc. A method for operating a refrigerating apparatus, which is activated when the operation is performed.