JPH03144263A - Heat accumulation type compression refrigerating cycle - Google Patents

Abstract

PURPOSE:To flexibly cope with a variation in a load by providing a concentration difference utility heat accumulator in which high temperature refrigerant vapor of a circulation system of a compression type refrigerator is used as a heat source and low temperature refrigerant liquid of the circulation system is used as a cooling source. CONSTITUTION:In a compression type refrigerator in which refrigerant is sealed in a circulation system having a compressor 1, a condenser 2, an expansion valve 3 and an evaporator 4, a concentration difference utility heat accumulator in which high temperature refrigerant vapor of the system of the refrigerator is used as a heat source and low temperature refrigerant liquid of the system is used as a cooling source, is provided. That is, when a heat demand (heat load) is reduced, a compression refrigerating cycle concentrates the absorption liquid of the accumulator by excess hot heat and cold heat, takes the hot heat or the cold heat by using absorptivity of the absorption liquid when the heat demand is increased, and adding it to the cycle. Thus, the output of the cycle can be standardized to always continue a stable rated operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat storage type compression type refrigeration cycle, and particularly to a heat storage type compression type refrigeration cycle that is suitable for improving refrigeration performance and saving power.

[Conventional technology]

Conventionally, the condenser of a vapor compression type (hereinafter simply referred to as compression type) refrigeration equipment is used as the heater of an absorption refrigeration equipment that cools by the chemical action of the refrigerant and the absorption liquid that absorbs it. A method using an evaporator of a type refrigeration system has been proposed (Japanese Patent Application Laid-open No. 218773/1983).

[Problem to be solved by the invention]

The prior art uses a compression refrigeration device as a source for heating and cooling the absorption liquid and refrigerant of the absorption refrigeration device. This means that the entire amount of the refrigerant compressed in the compression refrigeration system is sent to the heater of the absorption refrigeration system, and that the whole view of the refrigerant after adiabatic expansion in the compression refrigeration system is shown in the condenser of the absorption refrigeration system. The structure is structured to flow from one to the other.

Absorption refrigeration equipment can use waste heat, etc. as its driving energy, but unless such an environment exists, the power cost will be higher than other refrigeration equipment, and the equipment will be larger.

On the other hand, compression refrigeration equipment is relatively compact, but if the load (heat capacity for refrigeration, cooling, or heating) changes, it will operate intermittently or at a cycle that deviates from the rated cycle. This was handled by methods such as.

The former method of operation had the problem that the larger the capacity of the equipment, the longer it took to start and stop it, and the thermal distortion of each device due to repeated startups and stops could lead to failures or shortened service life. .

Furthermore, in the latter operating method, the operating characteristics deteriorate, so there is a problem that the efficiency of operating energy is poor.

The present invention has been made in view of the above, and an object thereof is to provide a refrigeration cycle that can flexibly respond to load fluctuations in a large-capacity compression type refrigeration cycle.

A second object is to provide a refrigeration cycle with improved operating energy efficiency against load fluctuations.

[Means to solve the problem]

The gist of the present invention for achieving the above object is as follows.

(1) In a compression type refrigeration system that is composed of a circulation system including a compressor, a condenser, an expansion valve, and an evaporator, and in which a refrigerant is sealed, a high-temperature refrigerant in the circulation system of the compression type refrigeration apparatus is A heat storage type compression type refrigeration cycle characterized in that a heat storage device using a concentration difference is installed, using steam as a heating source and a low-temperature refrigerant liquid in the circulation system as a cooling source.

The above method uses part of the heat of condensation of high-temperature, high-pressure refrigerant gas in a compression refrigeration system to heat a highly absorbent solution (hereinafter referred to as absorption liquid), evaporates the refrigerant, and produces a concentrated absorption liquid. A cycle is added in which the refrigerant vapor generated from the absorption liquid is condensed and stored using part of the heat of evaporation of the low-temperature, low-pressure refrigerant liquid in the compression refrigeration device.

(2) When the heat load of the compression type refrigeration cycle is low, the excess heat of the refrigerant circulating in the cycle is used to convert the concentrated liquid obtained by concentrating the absorbing liquid of the heat storage device using concentration difference, and the refrigerant evaporated and condensed from the absorbing liquid, respectively. The heat storage device is stored and when the heat load becomes high, the concentration difference utilizing heat storage device is operated using the stored & concentrated liquid and the stored refrigerant to replenish the shortfall in the heat load. (1) The heat storage compression type refrigeration cycle as described.

In the above, the evaporator and absorber of a normal absorption refrigeration system are configured with the concentrated and stored absorbent liquid and the condensate liquid that is stored by reducing the refrigerant vapor to zero, thereby obtaining cold heat or heat. The cold or warm heat is used as a supplementary heat source for the compression type refrigeration cycle. Thereby, the compression type refrigeration system can be operated at the rated value regardless of fluctuations in heat load.

(3) The above-mentioned device is characterized by comprising a detection means for detecting the degree of heat load, and a control device for controlling the flow rate of refrigerant from the compression refrigeration cycle to the concentration difference utilization heat storage device based on a signal from the detection means. The heat storage compression type refrigeration cycle described in (1) or (2).

The above system automates the operation of the attached heat storage device utilizing concentration difference by providing a temperature detection means for detecting fluctuations in heat load.

[Effect]

When the heat demand (heat load) decreases, the surplus hot and cold heat of the compression refrigeration cycle is used.

The absorption liquid of the heat storage device using concentration difference is concentrated and stored, and when the heat demand increases, the absorbency of the absorption liquid is used to extract hot or cold heat and this is added to the cycle. This makes it possible to level out the output of the refrigeration cycle.

As a result, even when the heat load decreases, stable rated operation can be maintained without intermittent operation of the compression refrigeration equipment or unreasonable operation by shifting the cycle. Failure of each device due to thermal strain can be reduced, and the life of the device can be extended.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is an example of a system diagram of a heat storage type compression type refrigeration cycle of the present invention, in which a compression type refrigeration cycle denoted by numerals 1 to 19 is combined with a concentration difference utilizing heat storage device denoted by numerals 20 and onwards. It is something that

First, the cycle of a compression refrigerator will be explained using the enthalpy/pressure diagram shown in FIG. 2.

The refrigerant (e.g. Freon R-22) compressed by the compressor 1 becomes high temperature and high pressure (point A in Figure 2) and passes through the pipe 10 to the condenser 2.
It is cooled and liquefied (point B in FIG. 2) and flows into the pipe 11. A cooling source (for example, water) for the condenser 2 is introduced through a pipe 16, heated, and discharged through a pipe 17. In other words, the condenser 2 is a heater and also serves as a heat supply source for the tube 17.

The refrigerant liquid in pipe 11 flows through pipe 12 via liquid reservoir 5 and reaches expansion valve 3 . The expansion valve 3 is adiabatically expanded by the low temperature,
The refrigerant becomes a low-pressure refrigerant liquid (point C in FIG. 2), flows through the pipe 13, and is introduced into the evaporator 4.

In the evaporator 4, a heating liquid such as water for evaporating the refrigerant is introduced from a pipe 18, heats and evaporates the refrigerant, and the water is cooled and discharged from a pipe 19. In other words, the heated liquid is cooled, and the heated liquid is supplied as cold energy to the demand side. The refrigerant heated in the evaporator 4 becomes steam (second target point)
After flowing through the pipe 14 and being introduced into the accumulator 6, it is sucked through the pipe 15 from the suction side of the compressor.

The sucked refrigerant vapor is compressed by the compressor 1 driven by the prime mover 7 in the same manner as described above, and the compressor is operated by repeating the process of bringing it to a high temperature and high pressure state (point A in FIG. 2).

As mentioned above, the amount of heat and cold is a value strictly determined by the specifications of the compressor, and conventionally, with respect to fluctuations in the demand for heat and cold (load), if the fluctuation is within the rated value, 1st
In the second method, some of the hot or cold heat is adjusted by exchanging heat with the atmosphere from another location, for example, from a radiator tower, or in the second method, the rotational speed of the prime mover of the compressor is changed to
Adjustments have been made by operating the compressor by shifting the points A to D shown in the figure, or, as a third method, by repeatedly stopping and starting the compressor.

However, in the first method, the generated heat is wasted, and the energy input to the prime mover 7 that drives the compressor 1 is wasted. Operating at a cycle that deviates from the rating of the second method is
This increases mechanical loss, resulting in a decrease in performance and a decrease in the coefficient of performance. Furthermore, in the third method, the ratio of unsteady states from start to steady state and from steady state to stop increases, which causes a decrease in the coefficient of performance as described above, and also causes damage to the parts that make up the equipment due to repeated starting and stopping. Thermal distortion caused by expansion and contraction due to heat can cause unexpected damage or failure, which can shorten the lifespan of a single device. Of course, it is self-evident that it is not possible to output cold or hot heat that exceeds the rated value of the compressor.

The present invention solves the above-mentioned problem by providing a heat storage device utilizing concentration difference, which is indicated by reference numerals 20 onward in FIG. 1. The heat storage device using concentration difference is disclosed in Japanese Patent Application Laid-open No. 61-180891.
As described in the issue, this is a device that utilizes the concentration and dilution of absorbent liquids.

The heat storage type compression type refrigeration cycle of the present invention is a thermal storage type compression type refrigeration cycle.

If the cold/heat load is small, perform the operations described below.

When the thermal load (not shown) is small, the temperature of the hot water flowing through the pipe 16 increases, which is detected by the temperature detection sensor 26.
If the temperature exceeds a preset temperature, valve 23.2 is activated.
4 and 25 (including slight opening and slight opening). For example, when the temperature exceeds a set value, the temperature detection sensor 26 and the control device (the control device is not shown) activate the valve 24.
By opening the valve 25 and closing the valve 23, a part of the refrigerant flowing through the pipe 10 in the state of high temperature and high pressure steam is transferred to the pipe 101.
and introduced into the heat exchanger 100 of the concentration diluter 20, which is a closed container of the heat storage device utilizing concentration difference. At this time, the dilute absorption liquid (for example, LiBr aqueous solution) sprayed from the nozzle 33 onto the surface of the heat exchanger 100 is heated and evaporated, and the concentrated absorption liquid is transferred to the tube 34. Heat recovery device 50. tube 36
The absorbent liquid is then introduced into the absorbent storage tank 30 and stored. The generated steam flows to the chamber 22 side.

The refrigerant that has heated the absorption liquid is liquefied and flows through the pipe 102 onto the pipe 1, which is the main piping system.

On the other hand, a portion of the low-temperature, low-pressure refrigerant liquid flowing through the pipe 13 is transferred to the pipe 30.
1 and introduced into the heat exchanger 300, the steam generated in the chamber 21 is cooled (heat exchanged), condensed and liquefied, and stored in the condensate storage tank 40 via the pipe 43. The refrigerant liquid flowing in the heat exchanger 300 is heated and turned into vapor, which flows through the pipe 302 and joins the main pipe 14 .

In addition, when the cold load is small, the temperature of the cold water flowing through the pipe 18 is detected by the temperature detection sensor 27, and the valve 2 is
3. Opening/closing control of 24 and 25 (control device not shown)
This is what we do.

As described above, according to the present invention, when the thermal and cold loads are small, it is possible to concentrate and store the absorption liquid of the heat storage device using concentration difference using the surplus heat of the refrigerant of the compressor. In other words, this operation accumulates energy.

Next, the operating method of the heat storage compression type refrigeration cycle of the present invention will be explained separately when the cooling load increases and when the heating load increases.

First, when the cooling load increases, that is, the pipe 1 in the evaporator 4
The case where the cold water temperature rises in No. 8 will be described.

Cooling water is flowed from equipment such as a cooling water tower (not shown) through the pipe 201 of the heat exchanger 200 of the concentrator diluter 20 of the heat storage device using concentration difference, without flowing the refrigerant through the refrigerant pipes 101, 102, 301, and 302. The concentrated absorption liquid described above is extracted from the absorption liquid storage tank 30 and sprayed into the heat exchanger 200 by the nozzle 33 via the pipes 31 and 32. On the other hand, the condensate stored during concentration is extracted from the condensate storage WJ 40 and sprayed onto the heat exchanger 400 through the pipe 41 and the nozzle 42 .

By the above operation, the pressure inside the concentrator diluter 20 decreases, and
The liquid (for example, water) sprayed onto the heat exchanger 400 on the opposite side evaporates and its temperature drops. The generated steam is transferred to the heat exchanger 200 on the 21 side.
The absorbent liquid is absorbed by the concentrated absorbing liquid that is being sprayed on the air, the temperature of the absorbing liquid increases, and the absorbent liquid is cooled by the heat exchanger 200. In addition, heat exchanger 2
Cooling water for cooling 00 is discharged from 202.

On the other hand, evaporate it on the side of the container 22. : The heated liquid removes heat from the liquid (for example, water) flowing inside the heat exchanger 400,
Can be evaporated continuously. Note that the liquid introduced from the pipe 401 to heat the heat exchanger 400 cools down and is discharged from the pipe 402, thereby serving as a source of cold heat. The cold source can be used as a cold source to reduce the temperature rise of the pipe 18, or can separately supply the cold heat from 402 to the demand side, in either case, when the cold load increases. I can handle it.

Further, when the thermal load taken out from the condenser 2 increases, that is, when the temperature in the tube 16 decreases, the tube 16
01, 102, 301, 302 (7) The refrigerant flow is stopped and the heat exchanger 20 of the concentration diluter 20 of the heat storage device using concentration difference
Take out the concentrated absorption liquid from the absorption liquid tank 30 onto the tube 31.
, 32 and spraying via nozzle 33.

On the other hand, the condensate is taken out from the condensate storage tank 40 and sprayed onto the heat exchanger 400 of the concentrator diluter 20 through the pipe 41 and nozzle 42 . Into the heat exchanger 400, a liquid (for example, water) at an appropriate temperature level is introduced from the pipe 401, and the temperature is increased by exchanging heat with a liquid (for example, water) at an appropriate temperature level, such as atmospheric temperature, river water, ground water, gray water, etc. , as described above, steam is generated on the 22 side,
21 side, heat is generated due to absorption phenomenon, and heat exchanger 200
The liquid (for example, water) flowing through the tube 202 is heated and taken out from the tube 202.

The heated liquid may be used to heat the water flowing through the pipe 16 in the same manner as described above, or may be heated separately in the '17
It is also possible to supply heat from 202 to the heat demand side.

FIG. 3 is a system diagram of another embodiment of the present invention.

Heat exchangers 500 and 6oO are attached to the middle of the refrigerant pipe 10, and the pipes 501, 502 and 601, 60
2. Refrigerants used in compression refrigeration cycles (e.g. Freon R)
-22) By using a different liquid (e.g. water), the heat exchanger 100 and the heat exchanger 300 shown in FIG.
was omitted.

Furthermore, tubes 501, 502 and tubes 601, 602
, namely heat exchangers 500 and 200 and heat exchangers 600 and 4.
By using a heat pipe for 00, the performance can be further improved.

〔Effect of the invention〕

According to the present invention, it is possible to easily vary the cold and hot heat output, which has been difficult with conventional compression refrigeration cycles.

In addition, when electricity is used as the motive power to operate the compressor, the heat energy is mainly used in the fir operation at night, and the heat energy is released during the day, which contributes to leveling the power load between day and night. can.

In addition, it is possible to achieve cold and hot heat output that exceeds the rated value without lowering the coefficient of performance, which was not possible with conventional compression refrigeration cycles.

[Brief explanation of the drawing]

FIGS. 1 and 3 are system diagrams of a heat storage compression type refrigeration cycle according to an embodiment of the present invention, and FIG. 2 is an enthalpy/pressure diagram of the compression type refrigeration cycle. 1... Compressor, 2... Condenser, 3... Expansion valve, 4
...Evaporator, 5..Liquid storage container, 6..Accumulator, 7..Motor, 10-19, 31, 32, 34, 3
6,41.43,101,102,201,202,3
01.302,401,402,501,502゜60
1.602...tube, 20...concentrator diluter, 23°24
．． 25...Valve, 26.27...Temperature detection sensor, 3
0... Absorption liquid storage tank, 33, 4.2... Nozzle, 40
... Condensate storage tank, 50 ... Heat recovery device, 100,200
゜300.400,500.600...Heat exchanger.

Claims (1)

[Scope of Claims] 1. A compression refrigeration system comprising a circulation system including a compressor, a condenser, an expansion valve, and an evaporator, and a refrigerant sealed in the system. A heat storage type compression type refrigeration cycle characterized in that a heat storage device using a concentration difference is installed in which the high temperature refrigerant vapor in the circulation system is used as a heating source and the low temperature refrigerant liquid in the circulation system is used as a cooling source. 2. When the heat load of the compression refrigeration cycle is low, the excess heat of the refrigerant circulating in the cycle is used to store the concentrated liquid obtained by concentrating the absorbing liquid in the heat storage device using concentration difference, and the refrigerant evaporated and condensed from the absorbing liquid. Claim 1, characterized in that when the heat load becomes high, the heat storage device using the concentration difference is operated by the stored concentrated liquid and the stored refrigerant to replenish the shortfall in the heat load. The heat storage compression type refrigeration cycle described in Section 1. 3. A claim characterized by comprising a detection means for detecting the degree of heat load, and a control device for controlling the flow rate of refrigerant from the compression refrigeration cycle to the concentration difference utilization heat storage device based on a signal from the detection means. The heat storage compression type refrigeration cycle according to item 1 or 2.