JP2004028375A - Refrigerating equipment combined with absorption type and compression type and operating method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating equipment that can be used for an air conditioner, economically and efficiently operated by selecting the optimal operation mode of a compression freezer. <P>SOLUTION: This freezing equipment is constituted by combining an absorption freezer having an evaporator E and a compression freezer having two or more compressors M1, M2, a first condenser C1 cooling by outside air or cooling water, a second condenser C2 connected having heat exchange relation with the evaporator E of the absorption freezer, a use side evaporator Ec providing a cooling effect, and a pipe circulating and connecting them. The compressors M1, M2 are connected in parallel with each other. The compressor M1 is connected by a pipe with the first condenser C1 at the discharge side, and the outlet side of the first condenser C1 is connected by a pipe with an inlet of the second condenser C2. The compressor M2 is connected at the discharge side with a pipe between the first and second condensers and is provided with a by-pass pipe 6 by-passing the compressor M2 in parallel with the compressor M2. The control valve V1 is provided to the by-pass pipe 6. A pipe on the discharge side of the compressor M2 and that of the compressor M1 can be connected by a pipe having a selector valve equivalent with a three-way valve. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigerating apparatus, and in particular, air that effectively utilizes a refrigerating effect from an absorption refrigerator or an absorption chiller / heater using exhaust heat from an engine, a turbine, various plants or the like as a heat source in combination with a compression refrigerator. The present invention relates to a refrigeration device that can be used as a harmony device.
[0002]
[Prior art]
Generally, in a cogeneration system, heat is discharged in the form of exhaust gas, hot water, or the like, along with power generation. Since the exhaust heat is not so high in temperature, it is classified as low potential energy and is often used for hot water supply or heating. Recently, absorption chillers have been operated with waste heat and used for cooling.
In the cogeneration system, the exhaust heat is obtained from exhaust gas and cooling water of a gas turbine or an engine, or cooling water of a fuel cell. In some cases, an absorption refrigerator is operated using only exhaust heat. However, as a combined cooling device, a method of using exhaust heat together with high potential energy to save the amount of high potential energy required for operation has been proposed and adopted. I have.
[0003]
By the way, since the exhaust heat changes according to the power generation amount, the supply amount is unstable, and it is difficult to obtain the capacity according to the cooling load when operating the absorption refrigerator only with the exhaust heat. In order to solve this, 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 is known. However, in the compression refrigerator of this refrigerator, the refrigerant vapor compressed by the compressor is condensed by a heat source side heat exchanger (condenser), and the condensate is supercooled by an evaporator of an absorption refrigerator. Regarding the absorption refrigeration effect, it is necessary to always use it while the compression chiller is running, regardless of the cooling load, and since it is used only for the subcooling, the ratio of the absorption refrigeration effect (ratio to the compression refrigeration effect) Therefore, there has been a problem that the power consumption of the motor driving the compressor cannot be significantly reduced.
[0004]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems of the prior art, and switches the operation mode of the compression refrigerator to an optimum one according to the amount of supplied exhaust heat and the cooling load, thereby achieving economical and efficient operation. And a refrigeration apparatus that can be used for an air conditioner.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an absorption refrigerator having an evaporator, two or more compressors, a first condenser cooled by outside air or cooling water, and heat exchange with an evaporator of the absorption refrigerator. A refrigeration apparatus combining a second condenser connected in a relationship, a use side evaporator exhibiting a refrigeration effect, and a compression refrigerator having a pipe for circulating them, wherein the two or more compressors are connected in parallel. Connecting the first compressor, the discharge side is connected to the first condenser by piping, the outlet side of the first condenser is connected to the inlet of the second condenser by piping, and the other compressor is The discharge side is connected to a pipe between the first condenser and the second condenser, and a bypass pipe for bypassing the compressor is provided in parallel with the compressor, and the bypass pipe has a control valve. A refrigeration apparatus characterized by the following.
[0006]
In the refrigeration apparatus, the compression refrigerator is connected to a discharge-side pipe of another compressor and a discharge-side pipe of the first compressor by a pipe having a switching valve equivalent to a three-way valve. The connection from the discharge side of one compressor to the discharge side of another compressor and the connection from the discharge side of the other compressor to the pipe between the first condenser and the second condenser can be switched. Before connecting to the discharge side of another compressor with a pipe between the first condenser and the second condenser, a switching valve equivalent to a three-way valve is provided, and the second condenser is provided. A bypass pipe for bypassing can be connected, and a plurality of compression refrigerators can be connected to one absorption refrigerator.
[0007]
Also, in the present invention, in the method for operating the refrigeration apparatus, the compression refrigerator includes a first compressor and another compressor, and includes the following operation modes (a) to (e);
(A) an operation mode in which the first compressor is operated, compressed steam is condensed in the first condenser, the other compressors are stopped, and the bypass control valve is fully closed;
(B) an operation mode in which the compressor is stopped, the bypass control valve is fully opened or the opening is adjusted, and the refrigerant vapor is condensed in the second condenser;
(C) an operation mode in which the first compressor is stopped, the other compressors are operated, the bypass control valve is fully closed, and the refrigerant vapor is condensed in the second condenser,
(D) Operation of operating the first compressor, condensing the compressed vapor in the first condenser, stopping other compressors, fully opening the bypass control valve, and condensing the refrigerant vapor in the second condenser. mode,
(E) an operation mode in which the first compressor is operated, the compressed steam is condensed in the first condenser, the other compressor is operated, and the compressed steam is condensed in the second condenser,
Operating the refrigeration system in at least three types of operation modes.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention utilizes an absorption refrigerator as a destination of the condensation heat of the compression refrigerator. In particular, the compression refrigerator depends on the cooling load and the operation state of the absorption refrigerator (load state on the absorption refrigerator effect, etc.). In order to save energy, for example, by reducing the required power (head) of the compressor by selecting the operating state of the compressor.
In the present invention, the ON / OFF of the function of the first condenser of the compression refrigerator is performed by supplying / stopping the cooling medium, and the compressor is a high-head machine and a low-head machine (or more). By providing a bypass circuit, the refrigerant flow (operating mode) is switched according to the load, and by selecting the compressor or the bypass, the cooling heat from the absorption refrigerator can be effectively used to reduce the power consumption of the compressor. it can.
[0009]
Next, the present invention will be described in detail with reference to the drawings.
1 to 3 are flow configuration diagrams showing connection examples of components on the compression refrigerator side of the refrigeration apparatus of the present invention. FIG. 4 shows an absorption refrigerator and a compression refrigerator of the refrigeration apparatus of the present invention. It is a flow block diagram which shows the example of a combined connection.
In the figure, M1 and M2 are compressors, Ec is an evaporator, C1 is a first condenser, C2 is a second condenser, V1 is a control valve, V2 and V3 are switching valves, and V4 and V5 are control valves (expansion valves). ), P is a liquid pump, INV is an inverter, 2 to 5 are circulation pipes, 6 and 8 are bypass pipes, and 7 is a connection pipe.
[0010]
Next, the operation mode using FIG. 1 will be described.
{Circle around (1)} Mode 1 (M1 + C1) is an operation mode when the absorption refrigeration effect transfer medium (such as cold water) is not supplied to the second condenser C2, such as when the absorption refrigerator is stopped, and is a normal compression refrigerator. The operation is the same as. The refrigerant is compressed by the compressor M1, and is condensed and supercooled in the first condenser C1. The control valve (expansion valve) controls the degree of supercooling and also controls the blow-through of refrigerant vapor. The liquefied refrigerant passes through the second condenser C2, enters the evaporator Ec, evaporates by removing heat of the medium to be cooled, and is sucked into the compressor M1 again to form a refrigeration cycle.
(2) Mode 2 (C2 direct condensation) is to stop the compressors M1 and M2, open the M1 bypass valve V1, and transfer the refrigerant evaporated by the evaporator Ec to the second when the cooling heat obtained by the absorption refrigerator is sufficient. This is an operation of condensing in the condenser C2 and circulating by natural circulation or a liquid pump.
In this mode, since the compressor is not operated, the required power can be significantly reduced.
[0011]
{Circle around (3)} Mode 3 (M2 + C2) operates the low-head compressor M2 to condense the refrigerant vapor in the second condenser C2, for example, when the temperature of the cold obtained in the absorption refrigerator is too high to directly condense. Driving. The M2 bypass valve is fully closed.
{Circle around (4)} In mode 4 (M1 + C1 + C2 direct condensation), the cooling temperature obtained by the absorption refrigerator is directly condensed. However, when the amount of heat is insufficient, the direct condensation in C2 and the high head compressor M1 + first condensation are performed. The device C1 is operated. The refrigerant condensed in C1 is supercooled in C2.
In this operation, the control valve (expansion valve) at the outlet of C1 may be slightly opened, and the refrigerant may be guided to the second condenser C2 in a two-phase state of the refrigerant vapor and the condensate. At this time, the refrigerant flow in the first condenser C1 becomes active, and the heat transfer deterioration due to the condensed refrigerant liquid is also eliminated, the heat transfer becomes very good, the condensing pressure decreases, and the compression power can be reduced. However, the load on the absorption refrigeration effect increases.
(5) Mode 5 (M1 + Cl, M2 + C2) is a mode in which the temperature of the cold heat obtained by the absorption refrigerator is insufficient and the amount of heat is also insufficient, and the high head compressor M1 + the first condenser C1 and the low head compression are used. The operation of the machine M2 + the second condenser C2 is performed.
[0012]
FIG. 2 shows a configuration in which a switching valve V2 is provided on the discharge side of M2 in FIG.
The compressor connected to the first condenser C1 can be selected.
In the operation of mode 1, when the temperature of the medium for cooling the first condenser C1 is equal to or higher than a predetermined value, the high head compressor M1 is selected, and when it is lower than the predetermined value, the low head compressor M2 is selected.
In FIG. 3, a switching valve V3 is provided in the pipes 3 of C1 and C2, and a pipe 8 that bypasses C2 is connected.
In order to adjust the load applied to the second condenser C2, the refrigerant liquid from the first condenser C1 can be bypassed to the second condenser C2.
[0013]
FIG. 4 is a flow diagram showing a combination of an absorption refrigerator and a compression refrigerator. A is an absorber, E is an evaporator, G is a regenerator, C is a condenser, SP is an absorption solution pump, and RP is a refrigerant. A pump, 1 is an absorption refrigerator, 10 is a heat exchanger, 11 to 14, 16 are solution pipelines, 15, 17, and 18 are refrigerant pipelines, 19 is a cold water circulation channel, 20 is a cooling water circulation channel, and 21 is a waste heat source flow. Road.
In FIG. 4, in the absorption refrigerator, the solution having absorbed the refrigerant passes from the absorber A to the regenerator G through the pipe 12 through the heated side of the heat exchanger 10 by the absorption solution pump SP. In the regenerator G, the solution is heated using exhaust gas from an external gas turbine or the like as a heat source, evaporates a refrigerant, is concentrated, and is introduced into the absorber A from the pipe 13 through the heating side of the heat exchanger 10. You.
On the other hand, the refrigerant vapor generated in the regenerator G is condensed by the cooling water in the condenser C and then guided to the evaporator E. In the evaporator E, the cold water can be taken out by removing latent heat from the chilled water circulation path 19. It becomes.
The compression refrigeration cycle has the configuration shown in FIG. 1, and the absorption refrigeration effect of the evaporator E is connected to the condenser C2 by a transport medium (for example, the cold water circulation path 19).
[0014]
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 using inexpensive fuel or the like as a heat source.
Each device constituting one compression refrigerator may be a plurality of devices.
Although described as a compression refrigerator, a mode in which heating operation is performed by a heat pump by switching pipes may be employed. At this time, heat may be supplied to the heat pump using the absorption refrigerator as a chiller / heater, or an exhaust heat source may be supplied directly to the heat pump.
[0015]
【The invention's effect】
According to the present invention, an economical and efficient operation can be performed by switching the operation mode of a compression refrigerator to an optimum one according to an amount of supplied exhaust heat and a cooling load, and the compressor is used for an air conditioner. It was possible to provide a refrigerating device that can be used.
[Brief description of the drawings]
FIG. 1 is a flow configuration diagram showing an example of a compression refrigerator of a refrigerator of the present invention.
FIG. 2 is a flow configuration diagram showing another example of the compression refrigerator of the refrigerator of the present invention.
FIG. 3 is a flowchart showing another example of the compression refrigerator of the refrigerator of the present invention.
FIG. 4 is a flow diagram showing an example in which an absorption refrigerator and a compression refrigerator of the refrigerator of the present invention are combined.
[Explanation of symbols]
M1, M2: compressor, Ec: evaporator, C1: first condenser, C2: second condenser, V1: control valve, V2, V3: switching valve, V4, V5: control valve (expansion valve), P : Liquid pump, INV: inverter, A: absorber, E: evaporator, G: regenerator, C: condenser, SP: absorption solution pump, RP: refrigerant pump, 1: absorption refrigerator, 2-5: circulation Piping, 6, 8: bypass piping, 7: connection piping, 10: heat exchanger, 11 to 14, 16: solution piping, 15, 17, 18: refrigerant piping, 19: cold water circulation, 20: cooling water circulation Road 21: Exhaust heat source flow path

Claims (5)

An absorption refrigerator having an evaporator, two or more compressors, a first condenser cooled by outside air or cooling water, a second condenser connected in a heat exchange relationship with an evaporator of the absorption refrigerator, A refrigeration system in which a utilization side evaporator to be used and a compression refrigerator having a pipe for circulating them are combined, wherein the two or more compressors are connected in parallel, and the first compressor is provided with a discharger. Side with the first condenser, the outlet side of the first condenser is connected with the inlet of the second condenser, and the other compressor has a discharge side with the first condenser and the second condenser. A refrigerating apparatus, wherein a bypass pipe is provided in parallel with the compressor, the refrigerating apparatus being connected to a pipe between the compressor and the compressor, and having a control valve in the bypass pipe. In the compression refrigerator, a discharge-side pipe of another compressor and a discharge-side pipe of the first compressor are connected by a pipe having a switching valve equivalent to a three-way valve, and the first compressor The connection from the discharge side of the other compressor to the discharge side of the other compressor and the connection from the discharge side of the other compressor to the pipe between the first condenser and the second condenser can be switched. The refrigeration apparatus according to claim 1, wherein In the compression refrigerator, a switching valve equivalent to a three-way valve is provided before connecting to a discharge side of another compressor with a pipe between the first condenser and the second condenser, and a second condenser is provided. The refrigeration apparatus according to claim 1 or 2, wherein a bypass pipe for bypassing is connected. 4. The refrigeration apparatus according to claim 1, wherein a plurality of compression chillers are connected to one absorption chiller. 5. The method of operating a refrigeration apparatus according to any one of claims 1 to 4, wherein the compression chiller has a first compressor and another compressor, and operates in the following (a) to (e). mode,
(A) The first compressor is operated, the compressed steam is condensed in the first condenser, the other compressors are stopped, the operation mode in which the bypass control valve is fully closed, and (b) the compressor is stopped. The operation mode in which the bypass control valve is fully opened or the opening degree is adjusted to condense the refrigerant vapor in the second condenser, (c) the first compressor is stopped, the other compressors are operated, and the bypass control valve is fully closed. An operation mode in which refrigerant vapor is condensed in the second condenser, (d) the first compressor is operated, the compressed vapor is condensed in the first condenser, and the other compressors are stopped; Is fully opened, the operation mode in which the refrigerant vapor is condensed in the second condenser, (e) the first compressor is operated, the compressed vapor is condensed in the first condenser, the other compressor is operated, and the compressed steam is operated. In at least three types of operation modes among the operation modes in which How the operation of the refrigeration system, characterized in that.

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