JPS629488Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field of the invention The invention relates to a control device for an absorption heat pump, a so-called reheating type absorption heat pump, which further heats hot water obtained by using heat dissipated by an absorption heat pump cycle with high-temperature refrigerant vapor. .

(b) Prior art and its problems In a dual-effect absorption heat pump, a reheating absorption heat pump uses refrigerant vapor to further heat the hot water flowing from the absorber to the condenser in a water heater attached to a high-temperature generator. is conventionally known.

However, when such reheating type absorption heat pumps are started, most of the refrigerant vapor generated in the high-temperature generator flows to the water heater side, and there is little flow of refrigerant to the evaporator side, which prevents absorption heat pump operation from occurring normally. not done,
The drawback was that the so-called boiler operation with poor thermal efficiency continued for a long time after the start of operation.

(c) Means for solving the problems In view of the above problems, the present invention has developed a so-called dual-effect reheating type absorption heat pump that uses a first sensor to sense the outlet temperature of the hot water condenser and the outlet temperature of the water heater. 1,
A second temperature detector is provided, and the heating amount control valve is fully opened so that the heating amount to the high temperature generator is supplied to the hot water load or more while the temperature sensed by the second temperature detector is below the lower limit set temperature; Until the temperature sensed by the second temperature detector reaches a predetermined temperature from the lower limit set temperature, the opening degree of the drain control valve that adjusts the refrigerant level in the water heater is controlled from fully open to fully closed. 1,
The signal from the second temperature detector is processed to control the opening degree of the heating amount control valve from fully open to the set opening degree, and the temperature sensed by the first temperature detector is changed from the predetermined temperature to the upper limit set temperature. Until then, by controlling the opening of the heating amount control valve from the set opening to fully closed using the signal from the first temperature detector, when the hot water temperature is low, the refrigerant generated energy is greater than the hot water load. is supplied to quickly raise the temperature of hot water in the water heater, and when the hot water take-out temperature exceeds the lower limit set temperature, the amount of heating is reduced and the refrigerant level in the water heater is raised to heat the hot water in the water heater. In other words, the amount of refrigerant separated by the high-temperature generator that circulates to the water heater is reduced, and more refrigerant is distributed to the condenser side, that is, the evaporator side, and the so-called boiler operation is changed from boiler operation to absorption heat pump in a short time after startup. Allows you to transition to driving,
Moreover, hot water close to a predetermined temperature can be stably and efficiently obtained.

(d) Embodiment FIG. 1 shows a control device for an absorption heat pump which is an embodiment of the present invention. , low and high temperature solution heat exchangers 6 and 7, a refrigerant conduit 8, a refrigerant liquid down-flow pipe 9, a refrigerant return pipe 11 with a refrigerant pump 10, a dilute liquid pipe 13 with a solution pump 12, an intermediate liquid pipe 14 and a concentrated liquid pipe. They are connected by pipes 15 to form an absorption heat pump cycle. 16 is a water heater attached to the high temperature generator 1, and a refrigerant conduit 8' and a refrigerant drain pipe 17 are connected so that a refrigerant circulation cycle is formed between the water heater and the high temperature generator 1. 18 is evaporator 4
19 is an absorber 5, a condenser 3, and a water heater 1;
6, a hot water pipe 20 is housed in the combustion chamber 21 of the high temperature generator 1, and 20 is a fuel pipe that supplies fuel to the combustion chamber 21 of the high temperature generator 1; the fuel pipe is equipped with a fuel control valve _V1 ;
is equipped with a drain control valve _V2 . S ₁ and S ₂ are
first and second temperature detectors that respectively detect the hot water condenser 3 outlet temperature and the water heater 16 outlet temperature;
C ₁ and C ₂ are first and second temperature regulators, respectively.
C ₃ is a controller that adjusts the opening degree _of the fuel control valve V ₁ in response to signals from the temperature regulators C _{1 and C 2 .} Until the temperature rises (e.g. from 38°C to 40°C), the signals from both the first and second temperature detectors S ₁ and S ₂ are processed and the opening degree of the fuel control valve V ₁ is adjusted (e.g. from fully open). to 1/3 of the set opening) and adjust the opening of the fuel control valve V ₁ using the signal from the first temperature sensor S ₁ up to the upper limit set temperature (for example, 42°C) of the first temperature sensor S 1 (for example, 1/3). It is designed to be adjusted from the set opening of /3 to fully closed). Furthermore, the opening of the drain control valve V ₂ is adjusted from fully open to fully closed via the second temperature regulator C ₂ based on the signal from the second temperature detector S ₂ from the lower limit setting temperature to a predetermined temperature. It is becoming more and more common.

Next, the control operation of the embodiment of the present invention will be explained (see FIG. 2).

(A) Operation from startup to transition to absorption heat pump operation At the beginning of operation, the hot water temperature is measured by the second temperature sensor S ₂
is below the lower limit set temperature, and for 100% hot water load (for example, Qkcal/hr load), the fuel control _valve
is fully opened by the controller _C3 , and heat exceeding the hot water load (for example, heat of 1.5 Qkcal/hr) is input to the high temperature generator 1. Therefore, most of the refrigerant vapor generated in the high temperature generator 1 is transferred to the water heater 1 with low flow resistance.
The hot water that flows into the water heater 6 side and mainly flows through the hot water pipe 19 in the water heater receives heat exceeding the hot water load and rapidly rises in temperature, and the temperature at the outlet of the hot water heater 16 rises to the second level.
When the temperature sensor S ₂ reaches the lower limit set temperature of 38°C and the temperature rises further, the fuel control valve V ₁ is activated by a signal from the controller C _3.
As the opening degree of the second temperature regulator decreases,
C ₂ also reduces the opening degree of the drain control valve V ₂ from fully open. As the opening degree of the drain control valve V ₂ is reduced, the amount of refrigerant circulating between the water heater 16 and the high temperature generator 1 decreases, and the flow rate of refrigerant to the condenser 3 side and eventually to the evaporator 4 increases accordingly. The temperature of the hot water flowing through the water heater 19 increases due to heat dissipation by the absorption heat pump cycle, that is, the heat dissipation from the absorber 5 and the condenser 3, while the heat transfer area between the hot water and the refrigerant vapor decreases due to the rise in the refrigerant liquid level in the water heater 16. As a result, heating of hot water in the water heater is suppressed. Then, when the temperature sensed by the second temperature detector S ₂ reaches a predetermined temperature (40°C), the drain control valve V ₂ is fully closed, and all of the refrigerant vapor generated in the high temperature generator 1 is supplied to the condenser 3 side. The temperature of hot water is raised mainly by absorption heat pump operation. At this time, the opening degree of the fuel control valve V ₁ is adjusted to 1/3 by the controller C ₃ , and the heat input to the high temperature generator 1 is continued until the temperature sensed by the second temperature detector S ₂ reaches the lower limit set temperature. 1/3 of the heat input (e.g. 0.5Qkcal/hr)
adjusted to. That is, at the time of transition to absorption heat pump operation, for example, the total amount of heat of 0.5Qkcal/hr of heat input to high temperature generator 1 and heat absorption amount of 0.5Qkcal/hr of evaporator 4 for hot water load Qkcal/hr is Heat is radiated by the absorber 5 and condenser 3, producing so-called hot water output.
Qkcal/hr is obtained, and the heat balance of the absorption heat pump is balanced.

By controlling in this way, it is possible to quickly shift to absorption heat pump operation with high efficiency (e.g. coefficient of performance of 200%), in other words, low fuel consumption. (for example, 40℃) hot water output (for example, Qkcal/hr output) can be obtained in a short time. Incidentally, the coefficient of performance here refers to the ratio of hot water output to the heat input to the high temperature generator 1.
The maximum coefficient of performance in so-called boiler operation where hot water is heated only with 6 is 100%.

(B) Operation after transition to absorption heat pump operation When the hot water temperature detected by the first temperature detector _S1 rises from the predetermined temperature to the upper limit setting temperature (for example, from 40℃ to 42℃), the controller _C3 Fuel control valve V ₁
Adjust to reduce the opening (for example, from 1/3 open to fully closed). By controlling in this way, when the load decreases or when the thermal energy of the waste heat fluid flowing through the heat source tube 18 increases, fuel consumption can be further reduced.In other words, the coefficient of performance can be further improved while maintaining the predetermined temperature. In addition, it is possible to obtain hot water close to that of the high temperature generator 1, and also to prevent abnormal increases in pressure and temperature within the high temperature generator 1.

Also, during operation of the absorption heat pump, if the thermal energy of the waste heat fluid decreases extremely or the load increases extremely, the outlet temperature of the hot water condenser 3 and the outlet temperature of the water heater 16 may return to the predetermined temperature (for example, 40°C). ), and if the temperature drops below the lower limit set temperature (e.g. 38℃), conversely, the opening degree of drain control valve V ₂ and fuel control valve V ₁ is increased to switch from so-called absorption heat pump operation to boiler operation. It is controlled so that the heat equivalent to or more than the load is transferred to the high temperature generator 1.
Since the temperature at the outlet of the hot water heater 16 can be returned to near a predetermined temperature (for example, 40° C.).

(e) Effects of the invention As described above, the present invention provides a dual-effect so-called reheating absorption heat pump in which hot water is supplied to the high-temperature generator while the condenser outlet temperature, that is, the hot water take-out temperature, is below the lower limit set temperature. Fully open the heating amount control valve so that the amount of heating is more than the hot water load heat amount,
Until the hot water extraction temperature reaches a predetermined temperature from the lower limit set temperature, the opening of the drain control valve is controlled from fully open to fully closed, and the amount of heating is controlled by processing the signals from the first and second temperature detectors. The opening of the valve is controlled from fully open to the set opening, and the heating amount control valve is controlled by the signal from the first temperature sensor until the hot water condenser outlet temperature reaches the predetermined upper limit temperature. Since the opening is controlled from the set opening to fully closed, it is possible to shift to absorption heat pump operation with less fuel consumption in a short time from the start of operation, and it is possible to stably and efficiently obtain hot water close to a predetermined temperature. This has a practical effect.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of the circuit configuration showing one embodiment of the control device of the present invention, Fig. 2a shows an example of the opening control of the drain control valve, and Fig. 2b shows the opening of the fuel control valve. It is a drawing showing an example of control. 1... High temperature generator, 2... Low temperature generator, 3... Condenser, 4... Evaporator, 5... Absorber, 6, 7... Low temperature, high temperature solution heat exchanger, 16... Water heater, 17... Refrigerant drain pipe, 18...Heat source pipe, 19...Hot water pipe, 20...Fuel pipe, _C1 , _C2 ...First and second temperature controller, _C3 ...Controller, _S1 , _S2 ...First and second temperature detector , V ₁ ... fuel control valve, V ₂ ... drain control valve.

Claims (1)

[Scope of utility model registration request] A high-temperature generator whose heating amount is controlled, a water heater attached to the generator, a low-temperature generator, a condenser, an evaporator, an absorber, and a solution heat exchanger are connected via piping, and waste hot water and other low-temperature fluids are supplied to the evaporator. In an absorption heat pump that extracts hot water by passing water from the absorber through the condenser to the water heater while supplying hot water, the setting is such that when the heating amount control valve is fully opened, more heat than the hot water load is supplied to the high temperature generator. and when the temperature detected by the hot water heater outlet temperature detector is between the first lower limit set temperature and the predetermined temperature, the flow rate of refrigerant drain returning from the water heater to the high temperature generator is adjusted based on the signal from the detector. The drain control valve is increased or decreased between fully open and fully closed, and the signals from the temperature sensor and the hot water condenser outlet temperature detector are processed to adjust the heating amount control valve between fully open and the set opening. When the detected temperature of the hot water condenser outlet temperature detector is between the predetermined temperature and the upper limit setting temperature, the signal from the detector causes the heating amount control valve to change between the set opening and fully closed. A control device for an absorption heat pump that is equipped with a control mechanism that increases and decreases.