JPH0765827B2 - Dual heat pump that can take out cold water and steam simultaneously - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cold water and steam simultaneous extraction dual heat pump that combines a high temperature side heat pump cycle and a low temperature side heat pump cycle, and in particular, a high boiling point refrigerant for steam extraction. The present invention relates to the binary heat pump described above, which allows the compressor outlet temperature to be adjusted to a constant temperature and prevents the high boiling point refrigerant from being deteriorated at high temperatures.

(Prior art) A high temperature side heat pump cycle that uses a high boiling point refrigerant and a low temperature side heat pump cycle that uses a low boiling point refrigerant are combined so that the high temperature heat output is from the high temperature side heat pump cycle, while the low temperature heat output is low. A so-called binary heat pump adapted to be taken out from the side heat pump cycle is known, and is disclosed in JP-A-62-52376, JP-A-62-52377, JP-A-57-2364 and JP-A-63-2053. Many are disclosed in the gazette and the like.

FIG. 3 is a diagram showing a general cycle configuration of such a binary heat pump. As a high temperature side cycle, a compressor (1), a condenser (2), a liquid receiver (3), an expansion valve (4),
The accumulator (6) is sequentially connected and connected, and one of the low-temperature side cycles has a compressor (7), a liquid receiver (8), a coagulation valve (9), an evaporator (10), and an accumulator ( 11) are sequentially connected and connected, and the condenser of the low temperature side cycle and the evaporator of the high temperature side cycle perform heat exchange in the cascade condenser (5). And, normally, CFC R-
High boiling point refrigerants such as 113 and R-114 are used, while low boiling point refrigerants such as R-12 and R-22 are used in the low temperature side cycle.

Next, referring to FIG. 3 above, the operation of these binary heat pumps will be described. In the high temperature side cycle, the high boiling point refrigerant discharged from the compressor (1) in a high temperature and high pressure state is
In the condenser (2), after being cooled by cooling water or the like circulating through the cooling tower (T) and liquefied, it is temporarily stored in the liquid receiver (3), and then in the low pressure liquid-gas mixture state by the expansion valve (4). After that, the cascade condenser (5) obtains heat from the refrigerant of the low temperature side cycle, evaporates, becomes a low-pressure gaseous state through the accumulator (6), and returns to the compressor (1). On the other hand, in the low temperature side cycle, the low boiling point refrigerant discharged from the compressor (7) gives heat to the high boiling point refrigerant through the cascade condenser (5) in a high temperature and high pressure state, and is itself cooled and condensed and liquefied. After being temporarily stored in the liquid receiver (8), a low-pressure liquid-gas mixture state is set by the expansion valve (9). Then, in the evaporator (10), heat is absorbed to cool the surroundings and the refrigerant itself evaporates. ,
A cycle of returning to the compressor (7) through a next accumulator (11) into a low-pressure gas state.

(Problems to be Solved by the Invention) However, the above-described binary heat pump is intended to lower the temperature on the low temperature side to below the freezing point by its cycle, and therefore the high temperature side condenser is intended only for heat dissipation. It was not necessary to raise the temperature of the high boiling point refrigerant discharged from the compressor to an extremely high level. However, if cold water and steam were to be taken out using this dual heat pump, the temperature and pressure of the high boiling point refrigerant discharged from the compressor would be abnormal. It becomes very high, promotes thermal decomposition of the refrigerant and refrigerating machine oil, causes deterioration, and causes a significant decrease in the coefficient of performance. Therefore, it has been practically difficult for the above-mentioned binary heat pump to take out steam from a heat source at room temperature.

The present invention copes with the above situation, and in a dual heat pump system for simultaneous extraction of cold water and steam, by providing a means for adjusting the compressor discharge temperature in the high boiling point refrigerant cycle, the high boiling point discharged from the refrigerating machine oil and the compressor. The purpose is to control so that the refrigerant does not deteriorate so that cold water and steam can be taken out simultaneously and stably.

(Means for Solving the Problem) That is, the feature of the dual heat pump of the present invention to meet the above-mentioned object is that a low boiling point refrigerant cycle in which an evaporator is for taking out cold water and a condenser is for taking out steam. The high-boiling-point refrigerant cycle is connected by a cascade condenser that exchanges heat between the low-boiling-side cycle condenser and the high-boiling-side cycle evaporator, and the high-boiling-side cycle between the receiver and the expansion valve In a binary heat pump with an economizer installed for heat exchange between a condenser and an accumulator, both heat exchangers are completely opposed to each other, and a receiver is provided in parallel with a circuit from the condenser to the economizer. By providing a bypass that directly enters the expansion valve, the high boiling point cooling discharged from the compressor of the high boiling point cycle is used in the bypass circuit and the circuit that enters the economizer from the receiver. The point is that a gas temperature measuring sensor for the medium and a flow rate adjusting valve that operates by a signal from the control device are provided.

(Operation) When cold water and steam are simultaneously taken out by using the binary heat pump as described above, a high-boiling point discharged from the compressor is used by using a heat exchanger which is a completely countercurrent flow for the steam taking-out condenser. It becomes possible to heat the steam up to near the refrigerant gas temperature, and as a result, the steam temperature above the condensation temperature is obtained, and cold water is taken out from the low boiling point refrigerant side evaporator in the conventional dual heat pump and from the high boiling point refrigerant side condenser. It is possible to take out steam. Then, when the cold water and the steam are taken out, by sensing the gas temperature of the high boiling point refrigerant discharged from the compressor of the high temperature side cycle, operating the flow rate adjusting valve, and adjusting the refrigerant flow rate flowing from the liquid receiver to the economizer, The degree of supercooling and the degree of superheat at the exit of the economizer change, the temperature of the gas discharged from the compressor in the high boiling point refrigerant cycle is adjusted to a constant temperature, deterioration of refrigerating machine oil and refrigerant can be prevented, and long-term continuous operation becomes possible.

Note that the above-mentioned action is a case where cold water and steam are taken out at the same time. However, there is no problem even if the cold water and steam are taken out at the same time, and it is possible to use only one of them without taking out at the same time, and the action is the same as that described above.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cycle system diagram of a dual heat pump for taking out cold water and steam according to the present invention. As in FIG. 3, the high temperature side cycle includes a compressor (1), a condenser (2) and a liquid receiver (3). , Expansion valve (4), cascade condenser (5),
The low-temperature cycle is configured by sequentially connecting and accumulating pipes (6), and the low-temperature cycle includes a compressor (7), a cascade condenser (5), a liquid receiver (8), an expansion valve (9), an evaporator (10), and an accumulator ( 11) is constructed by connecting piping in sequence. Further, in the above-mentioned configuration circuit, in the present invention, as shown in FIG. 1, between the liquid receiver (3) and the expansion valve (4) of the high temperature side cycle, and between the cascade condenser (5) and the accumulator (6). Economizer for heat exchange in
Is provided, and a bypass is provided in parallel with the circuit that enters the economizer (12) from the receiver (3) and that directly enters the expansion valve (4) from the receiver (3). Sensors (15) for measuring the gas temperature of the high boiling point refrigerant discharged from the compressor (1) of the cycle and flow rate adjusting valves (13), (14) operated by signals of a control device (16) are installed.

In the figure, (17) is the heat source water inlet in the low temperature side evaporator, (18) is the same cold water outlet, (19) is the heated water inlet in the high temperature side cycle, and (20) is the same steam outlet. Is.

Therefore, in both of the cycles that are thermally coupled by the cascade condenser (5) and the economizer (12), in the condenser (2), the heated water is piped so as to exchange heat with the refrigerant in a counterflow, and The heat exchange between the refrigerants in the economizer (12) and the cascade condenser (5) is also arranged so as to be performed in counterflow.

Next, the operating condition of the dual heat pump cycle in FIG. 1 will be described with reference to the Mollier diagram shown in FIG.
In the high temperature side cycle, the high boiling point refrigerant (R-114) discharged from the compressor (1) at high temperature and high pressure heats the counter-current water to be heated in the condenser (2), and outputs it as steam at the outlet (20).
As it is discharged, it cools itself into a high-temperature liquid refrigerant, which is temporarily stored in the liquid receiver (3) and then enters the economizer (12). In the Mollier diagram of FIG. 2, the state during this time is shown by lines from (f) and (g) to (i).
Then, in the economizer (12), heat exchange with the refrigerant flowing from the cascade condenser (5) flowing in the opposite direction to the accumulator (6) causes the refrigerant discharged from the receiver to
It is supercooled and the position (h) in FIG. 2 is obtained. Then, it goes into the expansion valve (4), becomes a low pressure state, reaches (e) of FIG. 2 again, reaches the cascade condenser (5), and absorbs the condensation heat of the low boiling point refrigerant in the low pressure side cycle. It becomes a gas refrigerant under low pressure and is overheated. This point is indicated by (j) in FIG. After that, the refrigerant that reaches the economizer (12) and is further heated by the refrigerant flowing from the liquid receiver (3) flowing in the opposite direction to the economizer (12) is further heated, and then passes through the accumulator (6) to the compressor (1). Completes the cycle as it is aspirated by
Steam is taken out.

In the above cycle, the high temperature side cycle is often (e) ', (j), (f)', in FIG.
(G) ', (i)', (h) ', (e)' may occur, but it is extremely desirable to carry them through the cycle as described above.

On the other hand, in the low temperature side cycle, the high temperature and high pressure low boiling point refrigerant discharged from the compressor (7) is shown by (c) in the Mollier diagram of FIG. 2 and then the next cascade condenser (5).
Then, the heat of condensation is given to the high boiling point refrigerant in the high temperature side cycle, and at the same time, the heat is taken away by the evaporation of the high boiling point refrigerant. This state is shown in FIG.

After that, the liquid is temporarily stored in the liquid receiver (8) and passes through the expansion valve, resulting in (a) in FIG. Next, it enters the evaporator (10), takes heat from the heat source water to make cold water, and is taken out from the cold water outlet (18).

On the other hand, it absorbs heat and becomes a gas refrigerant. This is (b) of FIG. Then, under the above operating conditions, the gas temperature of the high boiling point refrigerant discharged from the compressor in the high temperature side cycle is sensed, and the flow rate adjusting valves (13) and (14) are actuated in accordance with the detected gas temperature to the economizer (12). Of the high temperature side of the high temperature side economizer outlet to adjust the degree of supercooling and the low pressure side compressor suction gas superheat degree,
Keep the compressor discharge gas temperature constant.

More specifically, in the heat pump according to the present invention which operates as described above, for example, when the flow rate adjusting valve (13) is opened or the flow rate adjusting valve (14) is closed, the heat exchange amount in the economizer (12) is changed. Will increase,
As a result, the supercooling of the high-pressure side economizer (12) outlet refrigerant increases, and the refrigerant heating increases on the low-pressure side economizer (12) outlet side. In this state, the former is (h) ″ in the Mollier diagram of FIG.
, And the latter is indicated by (f) ″.

The compressor (1) discharge gas temperature becomes high. This is (g) ″ in the Mollier diagram.

Next, conversely, when the flow rate adjusting valve (13) is closed or the flow rate adjusting valve (14) is opened, the discharge gas temperature of the compressor (1) becomes low due to the effect opposite to the above.

Therefore, when the temperature sensor (15) senses an output signal from the temperature sensor (15) and the control device (16) responding to the output signal controls the flow rate adjusting valves (14) and (15), the compression is achieved. The discharge gas temperature of the machine (1) can be automatically maintained constant.

Thus, the high temperature side cycles (e), (j), (f),
(G), (i), (h), (e) and low temperature side cycles (a), (b), (c), (d), (a) are (e),
(J) and (d), (c) are thermally coupled by a cascade capacitor and the high temperature side cycle (i),
(H) (A part) and (j), (f) (B part) are thermally coupled by an economizer, and a high temperature side cycle (e), which is a Mollier diagram of a conventional binary heat pump,
(J), (g), (i) and (e) and the low temperature side cycles (a), (b), (c), (d) and (a) will result in higher thermal efficiency.

Although the case of simultaneously taking out cold water and steam has been described above, it is as described above that only one of cold water and steam may be used.

Further, it can be understood that the present invention can be used not only for cold water and steam but also for other fluids in a range that can be similarly applied, and cold water and steam broadly mean fluids.

(Effects of the Invention) As described above, in the two-way heat pump according to the present invention, in the high temperature cycle, the bypass including the flow rate adjusting valve is provided in parallel with the circuit that enters the economizer from the liquid receiver including the flow rate adjusting valve. Is provided to adjust the flow rate of the high temperature side refrigerant flowing to the economizer by opening and closing the flow rate adjusting valve. Even if the temperature is exceeded, it is possible to immediately return to a predetermined temperature by operating the flow rate control valve, and maintain the same temperature at a constant temperature, thereby suppressing abnormal pressure and temperature, and refrigerating oil or refrigerating machine oil. It has a remarkable effect of preventing deterioration and, as a result, preventing a decrease in the coefficient of performance, and making it possible to take out steam constantly and stably.

Moreover, by combining the flow rate adjusting valve with the temperature sensor and the control device, the compressor discharge temperature of the high boiling point refrigerant can be automatically maintained, and the cold water and steam can be taken out automatically.

[Brief description of drawings]

FIG. 1 is a cycle system diagram showing an example of a binary heat pump according to the present invention, FIG. 2 is a Mollier diagram based on the above cycle, and FIG. 3 is a cycle system diagram of a conventional binary heat pump. (1), (7) ... Compressor, (2) ... Condenser, (3),
(8) ... Liquid receiver, (4), (9) ... Expansion valve, (5) ... Cascade condenser, (6), (11) ... Accumulator, (10) ... Evaporator, (12) ... Economizer, ( 13),
(14) ... Flow control valve, (15) ... Sensor, (16) ...
Control device.

Front Page Continuation (72) Inventor Masao Fujishima 4-16- Shinhinodai, Sakai City, Osaka Prefecture 6-406 (72) Inventor Yasuhiro Hatano 3-33-2 Miharadai, Sakai City, Osaka Prefecture (72) Inventor Masami Ogata Osaka 2-26-9 Taguchiyama, Hirakata-shi (72) Inventor Yukitoshi Urata 2-29-14 Fukasawa-cho, Takatsuki-shi, Osaka (72) Inventor Tamotsu Ishikawa 29, Tenobe-cho, Tsunabe-cho, Kyoto Prefecture Shimogakiuchi (29 72) Inventor Masayuki Kawabata 2-11-6 Ikenomiya, Hirakata City, Osaka Prefecture

Claims (1)

[Claims] 1. A low-boiling-point refrigerant cycle in which an evaporator is for taking out cold water, and a high-boiling-point refrigerant in which a condenser is for taking out steam is heat-exchanged between a condenser in a low-boiling-side cycle and an evaporator in a high-boiling-side cycle. In the two-way heat pump, the economizer is installed to connect between the receiver and the expansion valve of the high-boiling-side cycle and between the evaporator and the accumulator while being connected by a cascade condenser that And a bypass that directly enters the expansion valve from the receiver in parallel with the circuit that enters the economizer from the receiver, and a high-boiling-side cycle in the bypass circuit and the circuit that enters the economizer from the receiver. Chilled water characterized by having a gas temperature measuring sensor for high boiling point refrigerant discharged from the compressor and a flow rate control valve operated by a signal from the control device, Care simultaneous removable 2-way heat pump.