JPH0634236A - Heat pump for sewage heat source - Google Patents

Abstract

PURPOSE:To prevent surge of a compressor by automatically lowering a set temperature of a temperature regulator to be provided at a warm water outlet of a condenser in response to a sewage temperature when the sewage temperature is lowered to a set value or lower in a heat pump for a sewage heat source using a turbo compressor. CONSTITUTION:At the time of room heating, refrigerant gas fed from a turbo compressor 3 to be driven by a motor 1 is introduced into a double bundle condenser 4, and heat exchanged with water supplied through a warm water tube C to obtain warm water for room heating. In this case, when a slight room cooling load is requested, fresh water is supplied to a double bundle evaporator 7 through a chilled water tube D, evaporation of refrigerant liquid utilizing heat of sanitary sewage water in a sewage tube B so far is conducted with fresh water to obtain chilled water. In this case, the sewage water temperature at an inlet side of the tube B is detected by a temperature detector 19, and when the sewage temperature becomes a set temperature or lower, a set temperature of an outlet temperature regulator 13 of warm water for room heating is sequentially lowered, thereby preventing surge of the compressor 3 due to insufficient capacity of the heat pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage heat source heat pump using a turbo compressor.

[0002]

2. Description of the Related Art FIGS. 3 and 4 are cycle flow diagrams of a sewage heat source heat pump using a turbo compressor. FIG. 3 shows the flow during the cooling operation, and FIG. 4 shows the flow during the heating operation. The circuits shown in these figures have basically the same configuration, but there are some parts which are not shown in the drawing because they are irrelevant depending on the respective operating conditions. Thick line piping in each figure
The main flow according to the operating state of each figure is shown.

In FIG. 3, 1 is a motor, 2 is a speed increaser connected to the same motor, 3 is a turbo compressor connected to the speed increaser, 4 is a double bundle connected to the discharge side of the compressor by a pipe. Condenser, 6 is an orifice connected to the condenser by piping, 7
Is a double bundle evaporator connected to the same orifice by a pipe, and this evaporator is connected to the suction side of the compressor 3 by a pipe. A is a sewage pipe connected to the condenser 4, B is a sewage pipe connected to the condenser 7, C is a hot water pipe connected to the condenser 4, and D is a cold water pipe connected to the condenser 7. 5 is a sewage pump provided on the sewage pipe A, 17 is a sewage pump provided on the sewage pipe B, 12 is a hot water pump provided on the hot water pipe C, and 8 is cold water provided on the cold water pipe D. It is a pump. Further, 15 is a shutoff valve, 16 is a filter, and these shutoff valve and filter are sewage pipe A, sewage pipe B,
It is provided in each of the hot water pipe C and the cold water pipe D.
13 is a temperature controller provided on the outlet side pipe of the hot water pipe C, 9 is a temperature controller provided on the outlet side pipe of the cold water pipe D, 11 is a suction vane provided on the compressor 3, and 10 is the same vane. Is a vane motor that drives the. Temperature controller 1
Reference numerals 3 and 9 are connected to the vane motor 10 by a signal line. Reference numeral 14 is a flow control valve provided on the pipe that bypasses the condenser 4 in the sewage pipe A. In FIG.
Reference numeral 18 denotes a flow rate control valve provided on a pipe that bypasses the evaporator 7 in the sewage pipe B. The flow rate control valve 14 is connected to the temperature controller 13 by a signal line. The flow rate control valve 18 of FIG. 4 is connected to the temperature controller 9 by a signal line. In order to avoid complication of the drawing, FIG.
The flow control valve 18 provided in the sewage pipe B is illustrated in the (flow diagram during cooling operation), and the flow control valve 14 provided in the sewage pipe A is not illustrated in FIG. 4 (flow diagram during heating operation). is there.

In FIG. 3 showing the cooling cycle flow,
The refrigerant gas compressed by the turbo compressor 3 driven from the motor 1 through the speed increaser 2 is transferred to the double bundle condenser (dou
It flows into the blebundle condenser 4 and is cooled and condensed by the sewage supplied by the sewage pump 5 through the sewage pipe A. The condensed refrigerant liquid evaporates in a double bundle evaporator 7 through the orifice 6, cools the cold water supplied through the cold water pipe D by the cold water pump 8, and supplies it as cooling water for cooling. The evaporated refrigerant gas is returned to the turbo compressor 3 to form a cycle. The cold water outlet temperature is controlled by the control signal from the temperature controller 9 via the vane motor 10 to adjust the angle of the suction vane 11 of the compressor and the refrigerant gas flow rate to control the cold water outlet temperature.

When a slight heating load is required during the cooling operation and hot water is required, the hot water pump 12 is started, fresh water is supplied to the double bundle condenser 4 through the hot water pipe C, and the sewage pipe A is supplied. The heat of the refrigerant gas that has been exhausted to the dirty water is exhausted to the water in the hot water pipe C to produce hot water used as a heat source for heating or the like. The hot water control is performed by detecting the hot water outlet temperature on the hot water pipe C by the temperature controller 13 and adjusting the amount of waste water in the sewage pipe A entering the double bundle condenser 4 by the flow rate control valve 14.

FIG. 4 shows the flow during the heating cycle. The water supplied through the hot water pipe C by the hot water pump 12 is deprived of the sensible heat and latent heat of liquefaction of the refrigerant gas by the double bundle condenser 4 to be warmed. It becomes hot water for use. The outlet temperature of the hot water is controlled by the control signal from the temperature controller 13 via the vane motor 10 to adjust the angle of the suction vane 11 of the compressor and adjust the flow rate of the refrigerant gas to control the outlet temperature of the hot water.

When a slight cooling load is required during the heating operation and cold water is required, the cold water pump 8 is started, fresh water is supplied to the double bundle evaporator 7 via the cold water pipe D, and the sewer pipe B is supplied. The heat of the refrigerant liquid that has been absorbed from the sewage supplied via the heat is absorbed from the water in the cold water pipe D,
Produces cold water used for cooling and other purposes. For the chilled water control, the temperature controller 9 detects the chilled water outlet temperature on the chilled water pipe D, and the sewage pump 17 adjusts the amount of sewage entering the double bundle evaporator 7 via the sewage pipe B by the flow rate control valve 18. Be seen.

As described above, the double handle condenser 4 and the double bundle evaporator 7 take out cold water and hot water at the same time during cooling to discharge unnecessary heat to dirty water, and take out hot water and cold water at the same time during heating. It makes it possible to absorb heat from dirty water. Since the average winter temperature of sewage in a city is generally about 13 to 15 ° C, it can be used as a heat source.

[0009]

When a turbo chiller is used as the sewage heat source heat pump, during the winter heating operation (Fig. 4), the sewage temperature is significantly lower than the design value, and the hot water outlet for heating is used. When operating at a constant temperature, the suction pressure of the turbo compressor decreases, the compression ratio increases, the capacity of the heat pump is insufficient, and the compressor causes surging,
The wind pressure may fluctuate, and operation may be stopped due to excessive vibration and noise. Although an auxiliary boiler is installed as a countermeasure against this, it causes an increase in construction cost, machine room space, complicated operation and maintenance / fuel cost.

According to the present invention, even when the sewage temperature is significantly lower than the design value in winter, the compressor does not surging and the auxiliary boiler is not installed.
It aims to enable the heating operation of the sewage heat source heat pump.

[0011]

Means for Solving the Problems The present invention has been made to solve the above problems, and in a sewage heat source heat pump using a turbo compressor, when the sewage temperature detector and the sewage temperature fall below a set value, Sewage characterized by being provided with a signal converter that automatically lowers the set temperature of a temperature controller provided on the outlet side of the hot water for heating of the condenser according to the temperature signal detected by the temperature detector. The present invention relates to a heat source heat pump.

[0012]

When the sewage temperature is significantly lower than the design value, the set temperature of the hot water outlet temperature controller is automatically and sequentially decreased, the suction pressure of the compressor is prevented from being lowered, and the compressor does not cause surging. Therefore, it is not necessary to install an auxiliary boiler.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cycle flow chart during heating operation according to an embodiment of the present invention. In the figure, 19 is a sewage temperature detector provided in the inlet side pipe of the sewage pipe B, 20 is a temperature detection value of the detector, and the signal is converted into a hot water pipe C.
Is a signal converter for sending to a temperature controller provided on the outlet side pipe of the. The configuration and operation of the parts other than the above are the same as those of the conventional technique, and thus the description thereof is omitted. Further, in FIG. 1, the flow control valve 14 on the sewage pipe A and the flow control valve 18 on the sewage pipe B shown in the section of the prior art are not shown in order to avoid complication of the drawing.

In the present apparatus, the set temperature of the outlet temperature controller 13 for hot water for heating is automatically and sequentially lowered by the signal of the signal converter 20 when the temperature detected by the sewage temperature detector 19 becomes lower than the set value. It has become.

FIG. 2 shows an example of the conversion mode in the above embodiment. When the sewage temperature lowers to 10 ° C., the set value of the hot water outlet temperature, which was 45 ° C. until then, starts to gradually decrease, and When the temperature is 7 ° C, it becomes 40 ° C. In this device, the hot water temperature is lowered even when the sewage temperature is temporarily lowered.
Even if the temperature is temporarily lowered to about 38 to 40 ° C., there is no problem because the room temperature does not change greatly. The conversion mode of the signal converter 20 is arbitrarily selected and set.

According to the present embodiment, even when the winter sewage temperature drops significantly below the design value, the heating operation of the sewage heat source heat pump is performed without causing surging in the compressor or installing an auxiliary boiler. It can be performed. It should be noted that the present invention allows the existing plant to be easily retrofitted on-site.

[0017]

In the sewage heat source heat pump of the present invention, when the sewage temperature detector and the sewage temperature falls below the set value, the hot water for heating the condenser is generated according to the temperature signal detected by the temperature detector. Since there is a signal converter that automatically lowers the set temperature of the temperature controller installed on the outlet side, even if the sewage temperature drops significantly below the design value, the compressor will not cause surging. Therefore, the heating operation can be performed without installing the auxiliary boiler.

[Brief description of drawings]

FIG. 1 is a cycle flow diagram during heating operation according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a signal conversion mode in the above embodiment.

FIG. 3 is a cycle flow diagram during a cooling operation of a conventional sewage heat source heat pump.

FIG. 4 is a cycle flow chart during heating operation of a conventional sewage heat source heat pump.

[Explanation of symbols]

 A Sewage piping B Sewage piping C Hot water piping D Cold water piping 1 Motor 2 Speed increaser 3 Turbo compressor 4 Double bundle condenser 5 Sewage pump 6 Orifice 7 Double bundle evaporator 8 Cold water pump 9 Temperature controller 10 Vane motor 11 Suction vane 12 Hot water pump 13 Temperature controller 14 Flow rate control valve 15 Shutoff valve 16 Filter 17 Sewage pump 18 Flow rate control valve 19 Sewage temperature detector 20 Signal converter

Claims (1)

[Claims] 1. A sewage heat source heat pump using a turbo compressor for heating a condenser according to a sewage temperature detector and a temperature signal detected by the temperature detector when the sewage temperature falls below a set value. A sewage heat source heat pump, comprising: a signal converter that automatically lowers a set temperature of a temperature controller provided on the outlet side of hot water.