JP2003307362A - Refrigerating equipment combined with absorption type and compression type - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide refrigerating equipment combined with an absorption type and a compression type and 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 first condenser Cc1 cooling using outside air or cooling water, a second condenser Cc2 connected to the evaporator E of the absorption refrigerating machine in a heat exchange relation, and evaporators Ec exhibiting refrigerating effects. The compression refrigerating machine is provided with a temperature set sensor setting a target temperature of medium cooled by the evaporators Ec, a temperature sensor detecting the temperature of medium, a means for adjusting a compression function force based on a difference between the set temperature and the detected temperature, and a means restricting the capacity of the second condenser Cc2. The compression refrigerating machine can adjust the compression capacity by the plurality of compressors Mc or inverters provided in the compressors Mc. <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. The present invention relates to a refrigerating apparatus that effectively uses the refrigerating effect of (1) in combination with a compression refrigerator.

[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, and 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 refrigeration system that can be used in an air conditioner that can be operated.

[0005]

In order to solve the above-mentioned problems, in the present invention, an absorption refrigerator having an evaporator E, one or more compressors, a first condenser cooled by outside air or cooling water,
A refrigeration apparatus comprising a combination of an evaporator E of the absorption refrigerator and a second condenser connected in a heat exchange relationship and a compression refrigerator having an evaporator Ec exhibiting a refrigerating effect, wherein the compression refrigerator is an evaporator. A temperature setting means for setting a target temperature of a medium (air, cold water, brine, etc.) cooled by the vessel Ec, and a temperature sensor for detecting the temperature of the medium are provided, and a difference between the set temperature and the detected temperature is provided. Based on the above, a refrigeration apparatus combining an absorption type and a compression type is provided, which is provided with means for adjusting the compression function force and means for limiting the capacity of the second condenser. .

In the refrigeration system, the compression refrigerator has a first condenser connected to the discharge side of the compressor, a second condenser connected to the suction side of the compressor, and a plurality of compressors.
One of the compression function force adjusting means is a control of the number of the plurality of compressors, or at least one of the compressors is provided with an inverter driven by variable frequency, and one of the compression function force adjusting means is It may be an inverter, and the means for limiting the capacity of the second condenser limits the flow rate provided in the flow path for transferring the medium carrying the refrigerating effect of the absorption refrigerator to the second condenser. Valve or said evaporator E
It can be a means for setting a large target value (set value) of the superheat degree of the valve for adjusting the superheat degree of the outlet refrigerant provided in c. In addition, the compression refrigerator has one absorption refrigerator,
Multiple units can be connected.

[0007]

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 3 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, Cc1 is a first condenser, Cc2 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 part, in which the refrigerant vapor from the evaporator Ec is sucked into the second condenser Cc2 while the compressor Mc is stopped, and the compressor Mc or the compressor Mc during operation of the compressor Mc. And is sucked into the second condenser Cc2. If the temperature of the heat transfer medium from the absorption type is low and the refrigerant vapor can be condensed in the second condenser Cc2, it is sucked into the second condenser Cc2 and condensed in the second condenser Cc2. If the temperature of the heat transfer medium from the absorption type is high and the refrigerant vapor cannot be condensed in the second condenser Cc2, it exists in the second condenser Cc2 in the form of refrigerant vapor, and heat transfer hardly occurs. In the figure, the subcooler Sc may be omitted.

FIG. 1B shows, as 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. 2 (a) is composed of a plurality of compressors Mc, here three, and FIG. 2 (b) is a case of a plurality of compressors, 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 Mc1 and the first condenser Cc1, and a system of the compressor Mc2 and the second condenser Cc2. In FIG. 3, the present invention is applied to the control of the second condenser Cc2 when the compressor Mc2 is stopped. The pressure is adjusted by the compressor Mc1 of the first condenser Cc1 system. The second system also operates depending on the operation mode. For example, when there is an operation permission signal from the absorption refrigerating machine side and the temperature of the carrier medium for the absorption refrigerating effect is equal to or higher than a predetermined temperature, the compressor is operated.

Next, the control of the refrigerating apparatus of the present invention will be described. First, in the control on the compression refrigerator side, in relation to the capacity control, the expansion valve V1 of each evaporator Ec is adjusted so that the superheat degree at the outlet of the evaporator Ec reaches 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
If there are multiple units, use the total value or weighted average value that takes into consideration the capacity of each evaporator. In the required capacity, for example, Table 1
The compressor Mc is operated at a frequency such as. 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. Since a difference of 0.4 ° C. is provided in the same region between when the room temperature has a downward slope and when the room temperature has an upward slope, this serves as a hysteresis, and frequent changes in frequency can be suppressed.

[0012]

[Table 1]

After the compressor Mc is stopped, the condensing capacity of the second condenser Cc2 is limited. When the means for limiting the condensing capacity of the second condenser Cc2 is the medium amount control valve V3 provided in the flow path that conveys the absorption refrigeration effect to the second condenser Cc2, the valve opening degree is, for example, as shown in Table 2. Adjust the opening. ΔT = −0.8 ° C.
Then, the valve is fully opened, ΔT = -1.8 ° C., the valve is fully closed, and the proportional opening is provided.

[Table 2]

When the means for limiting the condensing capacity of the second condenser is the increase of the superheat target value at the outlet of the evaporator Ec, for example, Table 3
Set the target superheat as shown in. 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. As described above, the reason why the condensing capacity of the second condenser is limited by the increase in the degree of superheat is to increase the degree of superheat, so that the flow rate of the refrigerant flowing through the evaporator is throttled, and as a result, the outlet pressure decreases, This is because the condensation capacity of the condenser is reduced. 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.

[0015]

[Table 3] When one compressor in FIG. 1 is controlled by an inverter, the compressor is operated at a frequency corresponding to the temperature difference as shown in Table 1 during the operation of the compressor. While the compressor is stopped, the method shown in Table 2 or Table 3 is used to adjust the capacity of the second condenser Cc2 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 the inverter is operating at the maximum rotation speed, one compressor is additionally operated when the differential temperature rises, and the compressor is stopped when the differential temperature drops while operating at the inverter minimum rotation speed (other than the inverter takes precedence. Stop. After the compressor is completely stopped, the second condenser C
Modulates the capacity of c2. Further, the first condenser Cc1 adjusts the expansion valve V2 at the outlet so that the degree of supercooling at the outlet of the first condenser reaches a target value, or adjusts the expansion valve V2 by liquid level control to prevent gas bypass. The second condenser Cc2 adjusts the number of rotations of the refrigerant pump RP so that the degree of supercooling at the outlet of the second condenser reaches a target value, or installs a valve after the refrigerant pump to adjust the valve opening degree, or controls the liquid level. Adjust the refrigerant pump speed or valve opening to prevent gas bypass.

Next, the control on the absorption refrigerating machine side is operated so as to make full use of the exhaust heat, and at the time of avoiding freezing of the evaporator refrigerant and avoiding the absorption solution crystal, the heat input amount from the heat source is limited. This control may be performed only on the absorption type side, regardless of the compression type. There is too much load on the absorption refrigerator, or there is more than the capacity of the heat source for the absorption type.
When the evaporation temperature or the refrigeration output temperature of the absorption type becomes too high, the flow rate of the heat medium to the subcooler is reduced, or the flow rate of the heat medium to the second condenser Cc2 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, the absorption refrigerator may be used as a cold / hot water machine to supply heat to the heat pump, or the exhaust heat source may be directly supplied to the heat pump.

[0019]

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, resulting in economical and efficient operation. It is a refrigeration system that can be used as an air conditioner.

[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.

[Explanation of symbols]

Mc, Mc1, Mc2: Compressor, Ec: Evaporator, Cc
1: First condenser, Cc2: Second condenser, Sc: Supercooler, Ta, TR, Ts: Temperature sensor, RP: Refrigerant pump, V1, V2, V3: Control valve

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25B 1/00 371 F25B 1/00 371B 371F 27/02 27/02 K (72) Inventor Takeichi Irie Ota-ku, Tokyo 11-1 Haneda Asahi-machi, EBARA CORPORATION (72) Inventor Tetsuya Endo 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo (72) Inventor Atsushi Aoyama 11 Asahi-machi, Ota-ku, Tokyo No. 1 In the EBARA CORPORATION (72) Inventor Tomoyuki Uchimura 11-11 Haneda Asahi-cho, Ota-ku, Tokyo Inside the EBARA CORPORATION (72) Inventor Yukaku Fukuzumi 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo Inside EBARA CORPORATION

Claims (5)

[Claims] 1. An absorption refrigerator having an evaporator E, one or more compressors, a first condenser cooled by outside air or cooling water, and a first condenser connected in a heat exchange relationship with the evaporator E of the absorption refrigerator. A refrigerating apparatus in which a second condenser and a compression refrigerator having an evaporator Ec exhibiting a refrigerating effect are combined, wherein the compression refrigerator sets a target temperature of a medium cooled by the evaporator Ec. And a temperature sensor for detecting the temperature of the medium, and means for adjusting the compression function force based on the difference between the set temperature and the detected temperature, and means for limiting the capacity of the second condenser. A refrigerating apparatus which is a combination of an absorption type and a compression type. 2. The compression refrigerating machine has a first condenser connected to a discharge side of the compressor, a second condenser connected to a suction side of the compressor, and a plurality of compressors. The refrigerating apparatus according to claim 1, wherein one of the force adjusting means is a control of the number of the plurality of compressors. 3. The compression refrigerator has a first condenser connected to a discharge side of the compressor, a second condenser connected to a suction side of the compressor, and at least one of the compressors has a variable frequency. 3. The refrigerating apparatus according to claim 1 or 2, wherein an inverter driven by is provided, and one of the compression function force adjusting means is the inverter. 4. The means for limiting the capacity of the second condenser is a valve for limiting the flow rate provided in the flow path for transferring the medium for carrying the refrigerating effect of the absorption refrigerator to the second condenser. The refrigerating apparatus according to claim 1, 2, or 3. 5. The means for limiting the capacity of the second condenser is means for setting a large target value of the superheat degree of a valve for adjusting the superheat degree of the outlet refrigerant provided in the evaporator Ec. The refrigerating apparatus according to claim 1, 2 or 3.